Sergey Revnivykh, Deputy Head of the GLONASS Directorate, Director of the GLONASS System Development Department, Academician M.F. Reshetnev "

Perhaps, there is not a single branch of the economy where satellite navigation technologies have not already been used - from all types of transport to agriculture. And the application areas are constantly expanding. Moreover, for the most part, receiving devices receive signals from at least two global navigation systems - GPS and GLONASS.

State of the issue

It just so happened that the use of GLONASS in the space industry in Russia is not as great as one might expect, given the fact that the main developer of the GLONASS system is Roskosmos. Yes, already many of our spacecraft, launch vehicles, upper stages have GLONASS receivers as part of onboard equipment. But so far they are either auxiliary means or are used as part of the payload. Until now, to carry out trajectory measurements, to determine the orbits of near-earth spacecraft, synchronization, in most cases, ground-based means of the command-measuring complex are used, many of which have long depleted their service life. In addition, the measuring instruments are located on the territory of the Russian Federation, which does not allow providing global coverage of the entire trajectory of spacecraft, which affects the accuracy of the orbit. The use of GLONASS navigation receivers as part of the standard on-board equipment for trajectory measurements will make it possible to obtain the orbit accuracy of low-orbit spacecraft (which constitute the main part of the orbital constellation) at the level of 10 centimeters at any point of the orbit in real time. At the same time, there is no need to involve the means of the command-measuring complex in carrying out trajectory measurements, to spend funds to ensure their operability and the maintenance of personnel. It is enough to have one or two stations for receiving navigation information from the aircraft and transmitting it to the flight control center for solving planning problems. This approach changes the entire strategy of ballistic and navigation support. But, nevertheless, this technology is already well developed in the world and does not present any particular difficulty. It only requires making a decision on the transition to such a technology.

A significant number of low-orbit spacecraft are satellites for remote sensing of the Earth and the solution of scientific problems. With the development of technologies and means of observation, increasing the resolution, the requirements for the accuracy of the binding of the received target information to the coordinates of the satellite at the time of the survey are increasing. In a posteriori mode, to process images and scientific data, in many cases, the orbit accuracy needs to be known at the centimeter level.

For special spacecraft of a geodetic class (such as Lageos, Etalon), which are specially created to solve fundamental problems of studying the Earth and refining models of spacecraft motion, centimeter accuracy of orbits has already been achieved. But it should be borne in mind that these vehicles fly outside the atmosphere and are spherical in order to minimize the uncertainty of solar pressure disturbances. For trajectory measurements, a global international network of laser rangefinders is used, which is not cheap, and the operation of the tools is highly dependent on weather conditions.

ERS and science spacecraft mainly fly at altitudes up to 2000 km, have a complex geometric shape, and are fully disturbed by the atmosphere and solar pressure. It is not always possible to use laser facilities of international services. Therefore, the task of obtaining the orbits of such satellites with centimeter accuracy is very difficult. The use of special motion models and information processing methods is required. Over the past 10-15 years, significant progress has been made in world practice to solve such problems using onboard high-precision GNSS navigation receivers (mainly GPS). The pioneer in this area was the Topex-Poseidon satellite (joint NASA-CNES project, 1992-2005, altitude 1,336 km, inclination 66), the orbital accuracy of which was provided 20 years ago at a level of 10 cm (2.5 cm in radius).

In the next decade in the Russian Federation, it is planned to launch a lot of ERS spacecraft for solving applied problems for various purposes. In particular, for a number of space systems, the binding of target information with very high accuracy is required. These are the tasks of reconnaissance, mapping, monitoring of ice conditions, emergency situations, meteorology, as well as a number of fundamental scientific tasks in the field of studying the Earth and the World Ocean, building a high-precision dynamic geoid model, high-precision dynamic models of the ionosphere and atmosphere. The accuracy of the position of the spacecraft is already required to know at the level of centimeters throughout the entire orbit. It's about posterior precision.

This is no longer an easy task for space ballistics. Perhaps the only way that can provide a solution to this problem is the use of measurements from an onboard GNSS navigation receiver and the corresponding means of high-precision processing of navigation information on the ground. In most cases it is a combined GPS and GLONASS receiver. In some cases, requirements may be put forward for the use of only the GLONASS system.

Experiment on high-precision determination of orbits using GLONASS

In our country, the technology for obtaining high-precision coordinates using geodetic-class navigation receivers has been quite well developed for solving geodetic and geodynamic problems on the Earth's surface. This is a so-called precise point positioning technology. A feature of the technology is the following:

* to process the measurements of the navigation receiver, the coordinates of which need to be clarified, the information from the navigation frames of the GNSS signals is not used. Navigation signals are used only for range measurements, primarily based on measurements of the carrier phase of the signal;

* High-precision orbits and onboard clock corrections, which are obtained on the basis of continuous processing of measurements of the global network of GNSS navigation signals receiving stations, are used as ephemeris-time information of navigation spacecraft. Most of the solutions are now used by the International GNSS Service (IGS);

* measurements of the navigation receiver, the coordinates of which need to be determined, are processed together with high-precision ephemeris-time information using special processing methods.

As a result, the coordinates of the receiver (the phase center of the receiver antenna) can be obtained with an accuracy of a few centimeters.

For solving scientific problems, as well as for the tasks of land management, cadastre, construction in Russia, for several years now, such means have existed and are widely used. At the same time, the author has not yet had information about the means that can solve the problems of high-precision determination of the orbits of low-orbit spacecraft.

An initiative experiment carried out a few months ago showed that we have prototypes of such means, and they can be used to create standard industry-specific means of high-precision ballistic and navigation support for low-orbit spacecraft.

As a result of the experiment, the possibility of using existing prototypes for high-precision determination of the orbit of LEO spacecraft at a level of several centimeters was confirmed.

For the experiment, the flying domestic satellite ERS "Resurs-P" No. 1 (near-circular sun-synchronous orbit with an average altitude of 475 km), equipped with a combined navigation receiver GLONASS / GPS, was chosen. To confirm the result, data processing was repeated for geodetic spacecraft of the GRACE system (joint project of NASA and DLR, 2002-2016, altitude 500 km, inclination 90), on board of which GPS receivers were installed. The features of the experiment are as follows:

* in order to assess the capabilities of the GLONASS system for determining the orbit of the Resurs-P spacecraft (general view is shown in Fig. 1), only GLONASS measurements were used (4 sets of onboard navigation receivers developed by JSC RIRV);

* to obtain the orbit of the spacecraft of the GRACE system (general view is shown in Fig. 2), only GPS measurements were used (measurements are freely available);

* High-precision ephemeris and corrections of the on-board clocks of the navigation satellites of the GLONASS and GPS systems, which were obtained at the IAC KVNO TsNIIMash on the basis of processing the measurements of the stations of the global network IGS (data are freely available), were used as assistance information. The IGS estimate of the accuracy of this data is shown in Fig. 3 and is about 2.5 cm. The location of the global network of GLONASS / GPS stations of the IGS service is shown in Fig. 4;

* a prototype of the hardware and software complex, providing high-precision determination of the orbit of low-orbit spacecraft (initiative development of JSC "GEO-MCC"). The sample also provides decoding of measurements of the onboard receivers of the Resurs-P spacecraft using high-precision ephemeris-time information and taking into account the peculiarities of the session operation of the onboard receivers. The prototype was tested according to the measurements of the spacecraft of the GRACE system.

Rice. 1. General view of the Resurs-P spacecraft.

Rice. 2. General view of the spacecraft of the GRACE system.

Rice. 3. Evaluation of the accuracy of the IAC KVNO TsNIIMash ephemeris by the IGS service. The accuracy of the assisting ephemeris information of the GLONASS navigation spacecraft (designation - IAC, dark blue dots on the graph) is 2.5 cm.

Rice. 4. Location of the global network of GLONASS / GPS stations of the international IGS service (source - http://igscb.jpl.nasa.gov/network/iglos.html).

As a result of the experiment, an unprecedented result was obtained for the domestic ballistic and navigation support of low-orbit spacecraft:

* Taking into account the assistance information and real measurements of the onboard navigation receivers of the Resurs-P spacecraft, a high-precision orbit of this spacecraft with an accuracy of 8-10 cm was obtained only from GLONASS measurements (see Fig. 5).

* In order to confirm the result during the experiment, similar calculations were carried out for geodetic spacecraft of the GRACE system, but using GPS measurements (see Fig. 6). The orbital accuracy of these spacecraft was obtained at a level of 3-5 cm, which fully coincides with the results of the leading analysis centers of the IGS service.

Rice. 5. The accuracy of the "Resurs-P" spacecraft orbit obtained from GLONASS measurements only with the use of assisting information, estimated from measurements of four sets of onboard navigation receivers.

Rice. 6. Accuracy of the GRACE-B spacecraft orbit obtained from GPS measurements only with the use of assisting information.

ANNKA system of the first stage

Based on the results of the experiment, the following conclusions objectively follow:

In Russia, there is a significant backlog of domestic development for solving the problems of high-precision determination of the orbits of LEO spacecraft at a competitive level with foreign information processing centers. On the basis of this groundwork, the creation of a permanent industry ballistic center for solving such problems will not require large expenditures. This center will be able to provide all interested organizations that require binding to the coordinates of information from remote sensing satellites, services for high-precision determination of the orbits of any remote sensing satellites equipped with GLONASS and / or GLONASS / GPS satellite navigation equipment. In the future, the measurements of the Chinese system BeiDou and the European Galileo can also be used.

It is shown for the first time that the GLONASS system measurements when solving high-precision problems can provide the solution accuracy practically no worse than the GPS measurements. The final accuracy depends mainly on the accuracy of the assisting ephemeris information and the accuracy of knowledge of the low-orbit spacecraft motion model.

Presentation of the results of domestic remote sensing systems with high-precision referencing to coordinates will dramatically increase its importance and competitiveness (taking into account the growth and market price) in the world market for the results of remote sensing of the Earth.

Thus, for the creation of the first stage of the Assisted Navigation system for LEO SC (code name - ANNKA system) in the Russian Federation, all the components are available (or are under construction):

* there is its own basic special software that allows, independently of the GLONASS and GPS operators, to receive high-precision ephemeris-time information;

* there is a prototype of special software, on the basis of which a standard hardware and software complex for determining the orbits of LEO spacecraft with an accuracy of centimeters can be created in the shortest possible time;

* there are domestic samples of on-board navigation receivers that allow solving the problem with such accuracy;

* Roscosmos is creating its own global network of GNSS navigation signal reception stations.

The architecture of the ANNKA system for the implementation of the first stage (posterior mode) is shown in Fig. 7.

The system functions are as follows:

* receiving measurements from the global network to the information processing center of the ANNKA system;

* formation of high-precision ephemeris for navigation satellites of GLONASS and GPS systems (in the future - for BeiDou and Galileo systems) in the ANNKA center;

* obtaining measurements of on-board satellite navigation equipment installed on board the low-orbit ERS satellite and transferring it to the ANNKA center;

* calculation of the high-precision orbit of the remote sensing spacecraft in the center of ANNKA;

* transfer of the high-precision orbit of the remote sensing spacecraft to the data processing center of the ground-based special complex of the remote sensing system.

The system can be created as soon as possible, even within the framework of the existing measures of the federal target program for the maintenance, development and use of the GLONASS system.

Rice. 7. The architecture of the ANNKA system at the first stage (a posteriori mode), which ensures the determination of the orbits of LEO spacecraft at a level of 3-5 cm.

Further development

The further development of the ANNKA system towards the implementation of the mode of high-precision determination and prediction of the orbit of LEO spacecraft in real time on board can radically change the entire ideology of ballistic and navigation support of such satellites and completely abandon the use of measurements of ground-based means of the command and measurement complex. It is difficult to say how much, but the operational costs of ballistic and navigation support will be reduced significantly, taking into account the payment for the work of ground assets and personnel.

In the USA, NASA created such a system more than 10 years ago on the basis of a communication satellite system to control TDRSS spacecraft and the GDGPS global high-precision navigation system created earlier. The system was named TASS. It provides assisting information to all scientific spacecraft and remote sensing satellites in low orbits in order to solve onboard orbit determination tasks in real time at a level of 10-30 cm.

The architecture of the ANNKA system at the second stage, which ensures the solution of problems of determining orbits on board with an accuracy of 10-30 cm in real time, is shown in Fig. eight:

The functions of the ANNKA system at the second stage are as follows:

* receiving measurements from stations for receiving GNSS navigation signals of the global network in real time to the ANNKA data processing center;

* formation of high-precision ephemeris for navigation satellites of GLONASS and GPS systems (in the future - for BeiDou and Galileo systems) in the ANNKA center in real time;

* tab of high-precision ephemeris on the SC-relay of communication systems (constantly, in real time);

* relaying of high-precision ephemeris (assisting information) by satellites-repeaters for low-orbit ERS spacecraft;

* obtaining a high-precision position of the remote sensing spacecraft on board using special satellite navigation equipment capable of processing received GNSS navigation signals together with assistance information;

* transmission of target information with high-precision referencing to the data processing center of a special ground-based remote sensing complex.

Rice. 8. The architecture of the ANNKA system at the second stage (real-time mode), which ensures the determination of the orbits of LEO spacecraft at the level of 10-30 cm in real time on board.

The analysis of existing capabilities, experimental results show that the Russian Federation has a good groundwork for creating a high-precision assisted navigation system for low-orbit spacecraft, which will significantly reduce the cost of controlling these vehicles and reduce the lag behind the leading space powers in the field of high-precision spacecraft navigation in solving urgent scientific and applied problems. In order to take the necessary step in the evolution of LEO SC control technology, it is only necessary to make an appropriate decision.

The ANNKA system of the first stage can be created as soon as possible with minimal costs.

To proceed to the second stage, it will be necessary to implement a set of measures that should be provided for within the framework of state or federal targeted programs:

* creation of a special communication satellite system to ensure continuous control of near-earth spacecraft, either in geostationary orbit, or in inclined geosynchronous orbits;

* modernization of the hardware and software complex for the formation of assisting ephemeris information in real time;

* completion of the creation of the Russian global network of stations for receiving navigation signals from GNSS;

* development and organization of production of onboard navigation receivers capable of processing GNSS navigation signals together with assistance information in real time.

The implementation of these measures is serious, but quite realizable work. It can be carried out by the URSC enterprises taking into account the already planned activities within the framework of the Federal Space Program and within the framework of the Federal Target Program for the maintenance, development and use of the GLONASS system, taking into account the corresponding adjustments. Estimation of the costs of its creation and the economic effect is a necessary stage, which should be done taking into account the planned projects for the creation of space systems of complexes for remote sensing of the Earth, satellite communication systems, space systems and scientific complexes. There is absolute confidence that these costs will pay off.

In conclusion, the author expresses sincere gratitude to the leading specialists in the field of domestic satellite navigation Arkady Tyulyakov, Vladimir Mitrikas, Dmitry Fedorov, Ivan Skakun for organizing the experiment and providing materials for this article, the IGS international service and its leaders - Urs Hugentoble and Ruth Nilan - for the opportunity make full use of the measurements of the global network of stations for receiving navigation signals, as well as all those who helped and did not interfere.

ERS satellite "Resurs-P"

Remote sensing of the Earth (ERS) - observation of the surface by aviation and space vehicles equipped with various types of imaging equipment. The working range of wavelengths received by the survey equipment is from fractions of a micrometer (visible optical radiation) to meters (radio waves). Sensing methods can be passive, that is, use the natural reflected or secondary thermal radiation of objects on the Earth's surface, caused by solar activity, and active, using the stimulated radiation of objects initiated by an artificial source of directional action. Remote sensing data obtained from (SC) are characterized by a large degree of dependence on the transparency of the atmosphere. Therefore, the spacecraft uses multichannel equipment of passive and active types, which register electromagnetic radiation in various ranges.

ERS equipment of the first spacecraft launched in the 1960s and 1970s. was of the trace type - the projection of the measurement area onto the Earth's surface was a line. Later, panoramic-type ERS equipment appeared and became widespread - scanners, the projection of the measurement area onto the Earth's surface is a strip.

Earth remote sensing spacecraft are used to study the natural resources of the Earth and to solve meteorological problems. Spacecraft for the study of natural resources are equipped mainly with optical or radar equipment. The advantages of the latter are that it allows observing the Earth's surface at any time of the day, regardless of the state of the atmosphere.

general review

Remote sensing is a method of obtaining information about an object or phenomenon without direct physical contact with this object. Remote sensing is a subsection of geography. In the modern sense, the term mainly refers to technologies of air or space sensing of terrain for the purpose of detecting, classifying and analyzing objects on the earth's surface, as well as the atmosphere and the ocean, using propagated signals (for example, electromagnetic radiation). They are divided into active (the signal is first emitted by an airplane or a space satellite) and passive remote sensing (only a signal from other sources is recorded, for example, sunlight).

Passive remote sensing sensors register a signal emitted or reflected by an object or adjacent territory. Reflected sunlight is the most commonly used radiation source, detected by passive sensors. Examples of passive remote sensing are digital and film photography, infrared, charge-coupled devices and radiometers.

Active devices, in turn, emit a signal to scan the object and space, after which the sensor is able to detect and measure the radiation reflected or generated by backscattering by the sensing target. Examples of active remote sensing sensors are radar and lidar, which measure the time delay between emitting and registering the returned signal, thus determining the location, speed, and direction of an object.

Remote sensing provides the ability to obtain data on dangerous, hard-to-reach and fast-moving objects, and also allows observation over large areas of the terrain. Examples of remote sensing applications include monitoring deforestation (for example, in the Amazon basin), the state of glaciers in the Arctic and Antarctic, and measuring the depth of the ocean using a lot. Remote sensing is also replacing expensive and relatively slow methods of collecting information from the Earth's surface, while at the same time guaranteeing human non-interference in natural processes in the observed territories or objects.

With the help of orbiting spacecraft, scientists have the ability to collect and transmit data in different ranges of the electromagnetic spectrum, which, when combined with larger air and ground measurements and analysis, provide the necessary data spectrum for monitoring current phenomena and trends such as El Niño and others. natural phenomena, both in the short and long term. Remote sensing is also of applied value in the field of geosciences (for example, nature management), agriculture (use and conservation of natural resources), national security (monitoring of border areas).

Data acquisition techniques

The main goal of multispectral studies and analysis of the data obtained is objects and territories that emit energy, which allows them to be distinguished against the background of the environment. An overview of satellite remote sensing systems is found in the overview table.

Daylight saving time is generally the best time to obtain remote sensing data (in particular, during these months the sun is greatest above the horizon and the day is longest). An exception to this rule is the acquisition of data using active sensors (for example, Radar, Lidar), as well as thermal data in the long wavelength range. In thermal imaging, in which the sensors measure thermal energy, it is better to use the time interval when the difference in ground temperature and air temperature is greatest. Thus, the best times for these methods are during the colder months, as well as a few hours before dawn at any time of the year.

In addition, there are some more considerations to consider. With the help of radar, for example, it is impossible to get an image of the bare surface of the earth with thick snow cover; the same can be said for the lidar. However, these active sensors are insensitive to light (or lack thereof), making them an excellent choice for high latitude applications (for example). In addition, both radar and lidar are capable (depending on the wavelengths used) of imaging the surface under a forest canopy, making them useful in highly overgrown regions. On the other hand, spectral data acquisition methods (both stereo imaging and multispectral methods) are applicable mainly on sunny days; Data collected in low light conditions tends to have a low signal-to-noise ratio, making it difficult to process and interpret. In addition, while stereo images are capable of displaying and identifying vegetation and ecosystems, this method (as with multi-spectral sensing) cannot penetrate tree canopies and obtain images of the earth's surface.

Remote sensing applications

Remote sensing is most commonly used in agriculture, geodesy, mapping, monitoring the surface of the earth and the ocean, as well as the layers of the atmosphere.

Agriculture

With the help of satellites, images of individual fields, regions and districts can be obtained with certainty in a cyclical manner. Users can receive valuable information about the state of the land, including crop identification, crop area definition, and crop status. Satellite data is used to accurately control and monitor agricultural performance at various levels. This data can be used to optimize farming and spatially oriented management of technical operations. The images can help determine the location of crops and the extent of land depletion, and can then be used to develop and implement a treatment plan to optimize the local use of agricultural chemicals. The main agricultural applications of remote sensing are as follows:

• vegetation:
  • crop type classification
  • crop condition assessment (crop monitoring, damage assessment)
  • yield assessment

• the soil
  • display of soil characteristics
  • display of soil type
  • soil erosion
  • soil moisture
  • display of tillage practice

Forest cover monitoring

Remote sensing is also used to monitor forest cover and species identification. Maps obtained in this way can cover a large area, while simultaneously displaying detailed measurements and characteristics of the area (type of trees, height, density). Using remote sensing data, it is possible to define and delineate different types of forest that would be difficult to achieve using traditional methods on the surface of the earth. Data is available in a variety of scales and resolutions to suit local or regional requirements. Requirements for the detail of the terrain display depends on the scale of the study. To display changes in forest cover (texture, density of leaves), apply:

• multispectral imagery: very high resolution data are needed to accurately identify species

• multiple images of the same territory are used to obtain information about seasonal changes of various types

• stereophotos - for differentiation of species, assessment of the density and height of trees. Stereo photographs provide a unique view of forest cover only accessible through remote sensing technology

• Radars are widely used in the humid tropics due to their ability to acquire images in all weather conditions

• Lidars allows you to get a 3-dimensional structure of the forest, to detect changes in the height of the earth's surface and objects on it. Lidar data helps estimate tree heights, crown areas, and the number of trees per unit area.

Surface monitoring

Surface monitoring is one of the most important and typical applications for remote sensing. The obtained data are used to determine the physical state of the earth's surface, for example, forests, pastures, road surfaces, etc., including the results of human activities, such as the landscape in industrial and residential areas, the state of agricultural areas, etc. Initially, a land cover classification system should be established, which usually includes land levels and classes. Levels and grades should be developed taking into account the purpose of use (national, regional or local), spatial and spectral resolution of remote sensing data, user request, and so on.

Detecting changes in the state of the earth's surface is necessary to update land cover maps and rationalize the use of natural resources. Changes are typically found when comparing multiple images containing multiple layers of data and, in some cases, comparing old maps and updated remote sensing images.

• seasonal change: agricultural land and deciduous forests change seasonally

• annual changes: changes in land surface or land-use area, such as deforestation or urban sprawl

Information about the land surface and changes in vegetation cover is directly necessary for the definition and implementation of environmental protection policies and can be used in conjunction with other data to perform complex calculations (for example, to determine the risks of erosion).

Geodesy

Airborne survey data collection was first used to detect submarines and obtain gravity data used to construct military maps. These data represent the levels of instantaneous disturbances of the Earth's gravitational field, which can be used to determine changes in the distribution of the Earth's masses, which in turn can be required for various geological studies.

Acoustic and near-acoustic applications

• Sonar: passive sonar, records sound waves emanating from other objects (ship, whale, etc.); active sonar, emits pulses of sound waves and registers the reflected signal. Used to detect, locate and measure parameters of underwater objects and terrain.

• Seismographs are a special measuring device that is used to detect and record all types of seismic waves. With the help of seismograms taken in different places in a certain area, it is possible to determine the epicenter of an earthquake and measure its amplitude (after it has occurred) by comparing the relative intensities and the exact timing of the oscillations.

• Ultrasound: Ultrasound sensors that emit high-frequency pulses and record the reflected signal. Used to detect water waves and determine the water level.

When coordinating a series of large-scale observations, most sensing systems depend on the following factors: the location of the platform and the orientation of the sensors. High quality instruments nowadays often rely on positional information from satellite navigation systems. Rotation and orientation are often determined by electronic compasses with an accuracy of about one to two degrees. Compasses can measure not only azimuth (i.e., the degree deviation from magnetic north), but also altitude (the value of the deviation from sea level), since the direction of the magnetic field relative to the Earth depends on the latitude at which the observation is taking place. For more accurate orientation, it is necessary to use inertial navigation, with periodic corrections by various methods, including navigation by stars or known landmarks.

Overview of the main remote sensing instruments

• Radars are mainly used in air traffic control systems, early warning systems, forest cover monitoring, agriculture and for obtaining large-scale meteorological data. Doppler radar is used by law enforcement agencies to control the speed of vehicles, as well as to obtain meteorological data on wind speed and direction, location and intensity of precipitation. Other types of information obtained include ionized gas data in the ionosphere. Artificial Aperture Interferometric Radar is used to obtain accurate digital elevation models of large areas of the terrain.

• Satellite laser and radar altimeters provide a wide range of data. By measuring the fluctuations in ocean water level caused by gravity, these instruments display the topography of the seabed with a resolution of the order of one mile. By measuring the height and wavelength of ocean waves with altimeters, you can find out the speed and direction of the wind, as well as the speed and direction of surface ocean currents.

• Ultrasonic (acoustic) and radar sensors are used to measure sea level, ebb and flow, and determine the direction of waves in coastal sea regions.

• Light detection and ranging technology (LIDAR) is well known for its applications in the military field, in particular in laser navigation of projectiles. LIDAR is also used to detect and measure the concentration of various chemicals in the atmosphere, while LIDAR on board aircraft can be used to measure the height of objects and phenomena on the ground with greater accuracy than can be achieved with radar technology. Remote sensing of vegetation is also one of the main applications of LIDAR.

• Radiometers and photometers are the most common instruments used. They capture reflected and emitted radiation over a wide frequency range. The most common are visible and infrared sensors, followed by microwaves, gamma ray sensors and, less commonly, ultraviolet sensors. These instruments can also be used to detect the emission spectrum of various chemicals, providing data on their concentration in the atmosphere.

• Stereo images from aerial photography are often used to probe vegetation on the Earth's surface, as well as to generate topographic maps in the development of potential routes by analyzing terrain images, combined with modeling of environmental features obtained by ground-based methods.

• Multispectral platforms such as Landsat have been in active use since the 1970s. These instruments have been used to generate thematic maps by imaging at multiple wavelengths of the electromagnetic spectrum (multi-spectrum) and are typically used on Earth observation satellites. Examples of such missions include the Landsat program or the IKONOS satellite. Land cover and land-use maps obtained by thematic mapping can be used for mineral exploration, detection and monitoring of land use, deforestation, and the study of plant and crop health, including vast tracts of agricultural land or woodland. Landsat satellite imagery is used by regulators to monitor water quality parameters including Secchi depth, chlorophyll density and total phosphorus. Meteorological satellites are used in meteorology and climatology.

• Spectral imaging produces images in which each pixel contains complete spectral information, displaying narrow spectral ranges within a continuous spectrum. Spectral imaging devices are used to solve various problems, including those used in mineralogy, biology, military affairs, and environmental measurements.

• As part of combating desertification, remote sensing allows observing areas that are at risk in the long term, determining the factors of desertification, assessing the depth of their impact, and providing the necessary information to decision-makers to take appropriate environmental protection measures.

Data processing

With remote sensing, as a rule, digital data processing is used, since it is in this format that remote sensing data are received at the present time. In a digital format, it is easier to process and store information. A two-dimensional image in one spectral range can be represented as a matrix (two-dimensional array) of numbers I (i, j), each of which represents the intensity of radiation received by the sensor from an element of the Earth's surface, which corresponds to one pixel in the image.

The image consists of n x m pixels, each pixel has coordinates (i, j)- line number and column number. Number I (i, j)- integer and is called the gray level (or spectral brightness) of the pixel (i, j)... If the image is obtained in several ranges of the electromagnetic spectrum, then it is represented by a three-dimensional lattice consisting of numbers I (i, j, k), where k Is the number of the spectral channel. From a mathematical point of view, it is not difficult to process digital data obtained in this form.

In order to correctly reproduce the image on digital records supplied by information receiving points, it is necessary to know the record format (data structure), as well as the number of rows and columns. Four formats are used which order the data as:

• sequence of zones ( Band Sequental, BSQ);

• zones alternating along lines ( Band Interleaved by Line, BIL);
• zones alternating in pixels ( Band Interleaved by Pixel, BIP);
• a sequence of zones with compression of information into a file by the method of group coding (for example, in jpg format).

V BSQ-format each area image is contained in a separate file. This is convenient when there is no need to work with all zones at once. One zone is easy to read and visualize, zone images can be loaded in any order you want.

V BIL-format zonal data is written to one file line by line, while the zones alternate along the lines: 1st line of the 1st zone, 1st line of the 2nd zone, ..., 2nd line of the 1st zone, 2nd line 2nd zone, etc. Such recording is convenient when all zones are analyzed simultaneously.

V BIP-format the zonal values ​​of the spectral brightness of each pixel are stored sequentially: first, the values ​​of the first pixel in each zone, then the values ​​of the second pixel in each zone, etc. This format is called combined. It is convenient when performing pixel-by-pixel processing of a multi-zone image, for example, in classification algorithms.

Group coding used to reduce the amount of raster information. Such formats are convenient for storing large images; to work with them, you need to have a means of unpacking the data.

Image files are usually accompanied by the following additional information related to snapshots:

• description of the data file (format, number of rows and columns, resolution, etc.);

• statistical data (characteristics of brightness distribution - minimum, maximum and average value, variance);
• map projection data.

Additional information is contained either in the header of the image file or in a separate text file with the same name as the image file.

According to the degree of complexity, the following levels of CW processing provided to users differ:

• 1A - Radiometric correction of distortions caused by differences in sensitivity of individual sensors.

• 1B - radiometric correction at the processing level 1A and geometric correction of systematic sensor distortions, including panoramic distortions, distortions caused by the rotation and curvature of the Earth, fluctuations in the altitude of the satellite orbit.

• 2A shows image correction at 1B level and correction in accordance with a given geometric projection without using ground control points. For geometric correction, a global digital elevation model ( DEM, DEM) with a step of 1 km on the ground. The used geometric correction eliminates systematic distortions of the sensor and projects the image into a standard projection ( UTM WGS-84), using known parameters (satellite ephemeris data, spatial position, etc.).

• 2B - image correction at 1B level and correction in accordance with a given geometric projection using ground control points;

• 3 - image correction at 2B level plus correction using terrain DEM (orthorectification).

• S - image correction using the reference image.

The quality of data obtained from remote sensing depends on their spatial, spectral, radiometric and temporal resolution.

Spatial resolution

It is characterized by the size of a pixel (on the surface of the Earth) recorded in a raster image - usually ranging from 1 to 4000 meters.

Spectral resolution

Landsat data includes seven bands, including the infrared spectrum, ranging from 0.07 to 2.1 µm. The Hyperion sensor of the Earth Observing-1 apparatus is capable of registering 220 spectral bands from 0.4 to 2.5 µm, with a spectral resolution of 0.1 to 0.11 µm.

Radiometric resolution

The number of signal levels that the sensor can record. Typically ranges from 8 to 14 bits, resulting in 256 to 16 384 levels. This characteristic also depends on the noise level in the instrument.

Temporary permission

The frequency of the satellite's flight over the surface area of ​​interest. It is useful when examining a series of images, for example, when studying the dynamics of forests. Initially, the analysis of the series was carried out for the needs of military intelligence, in particular, to track changes in infrastructure, the movements of the enemy.

To create accurate maps based on remote sensing data, a transformation that removes geometric distortion is required. An image of the Earth's surface with a device pointing straight down contains an undistorted image only in the center of the image. When shifting to the edges, the distances between the points on the image and the corresponding distances on the Earth become more and more different. Correction of such distortions is performed during the photogrammetry process. Since the early 1990s, most commercial satellite imagery has been sold already corrected.

In addition, radiometric or atmospheric correction may be required. Radiometric correction converts discrete signal levels, for example from 0 to 255, to their true physical values. Atmospheric correction removes spectral distortion introduced by the presence of the atmosphere.

B.A. Dvorkin

The active introduction of information satellite technologies as an integral part of the rapidly developing informatization of society radically changes the living conditions and activities of people, their culture, stereotype of behavior, way of thinking. A few years ago, household or car navigators were looked upon as a miracle. High-resolution space images on Internet services, such as Google Earth, people looked at and did not cease to admire. Now, not a single motorist (if there is no navigator in the car yet) will leave the house without first selecting the optimal route in the navigation portal, taking into account traffic jams. Navigation equipment is installed on the rolling stock of public transport, including for control purposes. Space images are used to obtain operational information in areas of natural disasters and for solving various problems, for example, municipal administration. Examples can be multiplied and they all confirm the fact that the results of space activities have become an integral part of modern life. It is also not surprising that various space technologies are often used together. Hence, of course, the idea of ​​integrating technologies and creating unified end-to-end technological chains lies on the surface. In this sense, the technology of remote sensing of the Earth (ERS) from space and global navigation satellite systems (GNSS) is not an exception. But first things first…

GLOBAL NAVIGATION SATELLITE SYSTEMS

The Global Navigation Satellite System (GNSS) is a complex of hardware and software that allows you to get your coordinates at any point on the earth's surface by processing satellite signals. The main elements of any GNSS are:

• orbital constellation of satellites;
• ground control system;
• receiving equipment.

Satellites constantly transmit information about their position in orbit, ground stationary stations provide monitoring and control of the position of satellites, as well as their technical condition. The receiving equipment is a variety of satellite navigators that are used by people in their professional activities or everyday life.

The principle of operation of GNSS is based on measuring the distance from the antenna of the receiving device to the satellites, the position of which is known with great accuracy. Distance is calculated from the propagation delay time of the signal transmitted by the satellite to the receiver. To determine the coordinates of the receiver, it is enough to know the position of the three satellites. In fact, signals from four (or more) satellites are used to eliminate the error caused by the difference between the clock of the satellite and the receiver. Knowing the distances to several satellites of the system, using conventional geometric constructions, the program "wired" into the navigator calculates its position in space, thus, GNSS allows you to quickly determine the location with high accuracy at any point on the earth's surface, at any time, in any weather conditions ... Each satellite of the system, in addition to basic information, also transmits auxiliary information necessary for the continuous operation of the receiving equipment, including a complete table of the position of the entire satellite constellation, transmitted sequentially for several minutes. This is necessary to speed up the operation of the receiving devices. It should be noted that an important characteristic of the main GNSS is that for users with satellite receivers (navigators), receiving signals is free.

A common disadvantage of using any navigation system is that under certain conditions the signal may not reach the receiver, or arrive with significant distortion or delays. For example, it is almost impossible to determine your exact location inside a reinforced concrete building, in a tunnel, in a dense forest. To solve this problem, additional navigation services are used, such as, for example, A-GPS.

Today, several GNSSs operate in space (Table 1), which are at different stages of their development:

• Gps(or NAVSTAR) - operated by the US Department of Defense; currently the only fully deployed GNSS available 24/7 to users around the world;
• GLONASS- Russian GNSS; is in the final stage of full deployment;
• Galileo- European GNSS, which is at the stage of creating a satellite constellation.

We will also mention the national regional GNSS of China and India, respectively - Beidou and IRNSS, which are under development and deployment; distinguished by a small number of satellites and nationally oriented.

Characteristics of the main GNSS as of March 2010

Let's consider some of the features of each GNSS.

Gps

The basis of the American GPS system are satellites (Fig. 2), orbiting the Earth along 6 circular orbital trajectories (4 satellites in each), at an altitude of about 20 180 km. Satellites transmit signals in the ranges: L1 = 1575.42 MHz and L2 = 1227.60 MHz, the latest models also in the L5 = 1176.45 MHz range. The system is fully operational with 24 satellites, however, in order to increase positioning accuracy and reserve in case of failures, the total number of satellites in orbit is currently 31 satellites.

Rice. 1 GPS Block II-F spacecraft

GPS was originally intended for military use only. The first satellite was launched into orbit on July 14, 1974, and the last of all 24 satellites required to fully cover the earth's surface was launched into orbit in 1993. It became possible to use GPS to accurately target rockets to stationary, and then to mobile objects in the air and on the ground. To restrict access to accurate navigation information for civilian users, special interference was introduced, however, they were canceled since 2000, after which the accuracy of determining coordinates using the simplest civilian GPS navigator ranges from 5-15 m (the height is determined with an accuracy of 10 m) and depends on the conditions for receiving signals at a particular point, the number of visible satellites and a number of other reasons. The use of the WAAS global differential correction system improves the GPS positioning accuracy for North America to 1–2 m.

GLONASS

The first satellite of the Russian satellite navigation system GLONASS was launched into orbit back in Soviet times - on October 12, 1982. The system was partially put into operation in 1993 and consisted of 12 satellites. The basis of the system should be 24 satellites moving above the Earth's surface in three orbital planes with an inclination of 64.8 ° and an altitude of 19,100 km. The measuring principle and signal transmission ranges are similar to the American GPS GLONASS system.

rice. 2 Spacecraft GLONASS-M

Currently, there are 23 GLONASS satellites in orbit (Fig. 2). The last three spacecraft were launched into orbit on March 2, 2010. Now they are used for their intended purpose - 18 satellites. This ensures continuous navigation almost throughout the entire territory of Russia, and the European part is provided with a signal for almost 100%. According to plans, the entire GLONASS system will be deployed by the end of 2010.

At present, the accuracy of determining coordinates by the GLONASS system is slightly lower than similar indicators for GPS (no more than 10 m), while it should be noted that the combined use of both navigation systems significantly increases the positioning accuracy. To improve the performance of GPS, GLONASS and Galileo systems in Europe and to increase their accuracy, the European Geostationary Navigation Coverage Service (EGNOS) is used.

Galileo

The European GNSS Galileo is designed to solve navigation problems for any mobile objects with an accuracy of less than 1 m. Unlike the American GPS and Russian GLONASS, Galileo is not controlled by the military departments. Its development is carried out by the European Space Agency. Currently, there are 2 test satellites in orbit, GIOVE-A (Fig. 3) and GIOVE-B, launched in 2005 and 2008, respectively. The Galileo navigation system is slated to be fully deployed in 2013 with 30 satellites.

rice. 3 Spacecraft GIOVE-A

SATELLITE NAVIGATORS

As already noted, receiving equipment is an integral part of any satellite navigation system. The modern market for navigation receivers (navigators) is as diverse as the market for any other electronic and telecommunication products. All navigators can be subdivided into professional receivers and receivers used by a wide range of users. Let us dwell on the latter in more detail. Various names are used for them: GPS navigators, GPS trackers, GPS receivers, satellite navigators, etc. Recently, navigators built into other devices (PDAs, mobile phones, communicators, watches, etc.) have become popular. .). Among the actual satellite navigators, a special large class is made up of car navigators. Navigators designed for hiking, water, etc. trips are also becoming widespread (they are often called simply GPS navigators, despite the fact that they can also receive GLONASS signals).

A mandatory accessory for almost all personal navigators is a GPS chipset (or receiver), a processor, RAM and a monitor for displaying information.

Modern car navigators are able to plot a route taking into account the traffic organization and carry out address search. A feature of personal navigators for tourists is, as a rule, the ability to receive a satellite signal in difficult conditions, such as a dense forest or mountainous terrain. Some models have a waterproof case with increased shock resistance.

The main manufacturers of personal satellite navigators are:

• Garmin (USA; navigators for air, automobile, motorcycle and water transport, as well as for tourists and athletes)
• GlobalSat (Taiwan; navigation equipment for various purposes, including GPS receivers)
• Ashtech (formerly Magellan) (USA; personal and professional navigation receivers)
• MiTac (Taiwan; car and travel navigators, pocket personal computers and communicators with built-in GPS-receiver under the brands Mio, Navman, Magellan)
• ThinkWare (Korea; personal navigation devices under the I-Navi brand)
• TomTom (Netherlands; car navigators), etc.

Professional navigation equipment, including for engineering, geodetic and mine surveying, is produced by such companies as Trimble, Javad (USA), Topcon (Japan), Leica Geosystems (Switzerland), etc.

As already noted, a large number of personal navigation devices are currently being produced, differing in their capabilities and price. As an illustration, we will describe the features of only one sufficiently "advanced" device in order to characterize the capabilities of the entire class of modern GPS navigators. This is one of the latest innovations in the popular series of car navigators - TomTom Go 930 (description taken from the GPS-Club website - http://gps-club.ru).

The TomTom GO 930 (Fig. 6) combines the latest trends in car navigation - maps of several continents, wireless headset and unique Map Share ™ technology

rice. 4 TomTom GO 930 Car Navigator

All TomTom devices are developed in-house and are completely plug & play, which means they can be simply taken out of the box and used without having to read long instructions. An intuitive interface and "icons" in Russian will allow drivers to easily plan a route. Clear voice instructions in Russian help motorists reach their destination easily and stress-free. The navigator supports wireless control and Enhanced Positioning Technology (EPT), designed for uninterrupted navigation even in tunnels or densely built-up areas.

The TomTom navigation map provider is Tele Atlas, part of the TomTom Group. In addition to the fact that TomTom has fully Russified maps, it is the only navigation solution provider that offers maps of Europe and the United States on select navigator models.

The world's road infrastructure changes by 15% annually. Therefore, TomTom gives its users the opportunity to download the latest map version free of charge within 30 days of using the navigation device for the first time, as well as access to the unique Map Share ™ technology. TomTom navigation users can download a new map from the TomTom HOME service. Thus, the latest version of the map can be accessed at any time. What's more, motorists can use Map Share ™ technology, a free manual map update right on the navigator as soon as traffic changes become known, with just a few taps on the touchscreen. Users can make changes to street names, speed limits on certain sections of the road, driving directions, blocked passages, and changes to POIs (points of interest).

TomTom's unique map-sharing technology enhances navigation by allowing users to instantly make changes directly to their map. In addition, the user can receive information about similar changes made by the entire TomTom community.

This card sharing feature allows you to:

• change the maps of your TomTom device daily and immediately;
• gain access to the world's largest community of users of navigation devices;
• share updates daily with other TomTom users;
• get full control over downloaded updates;
• use the best and most accurate maps in any location.

CARDS FOR PERSONAL SATELLITE NAVIGATORS

Modern navigators are unthinkable without the presence of full-fledged large-scale maps in them, which show objects not only along the route of movement, but also throughout the survey area (Fig. 7).

rice. 5 Sample small-scale navigation chart

Both raster and vector maps can be loaded into navigators. We will talk about one of the types of raster information in particular, but here we will note that paper maps scanned and loaded into GPS receivers are not the best way to display spatial information. In addition to the low positioning accuracy, there is also the problem of binding the map coordinates to the coordinates issued by the receiver.

Vector digital maps, especially in GIS formats, are actually a database that stores information about the coordinates of objects in the form of, for example, "shapefiles" and, separately, qualitative and quantitative characteristics. With this approach, the information takes up much less space in the memory of navigators and it becomes possible to download a large amount of useful reference information: gas stations, hotels, cafes and restaurants, parking lots, attractions, etc.

As mentioned above, there are navigation systems that allow the user to supplement the navigator maps with their own objects.

In some personal navigation devices, especially those intended for tourists, it is possible to put objects on your own (that is, actually make your own maps and diagrams). For these purposes, a special simple graphic editor is provided.

Special attention should be paid to regime issues. As you know, in Russia, there are still restrictions on the use of large-scale topographic maps. This is quite a hindrance to the development of navigational cartography. However, it should be noted that at present the Federal Service for State Registration, Cadastre and Cartography (Rosrrestr) has set the task by 2011 to have full coverage of the Russian Federation (economically developed regions and cities) with digital navigation maps of scales 1:10 000, 1:25 000, 1:50 000. These maps will display navigation information represented by a road graph, digital cartographic background and thematic information (roadside infrastructure and services).

NAVIGATION SERVICES

The development and improvement of satellite navigation systems and receiving equipment, as well as all the active implementation of WEB technologies and WEB services, gave rise to the emergence of various navigation services. Many models of navigators are able to receive and take into account information about the traffic situation when planning a route, avoiding traffic congestion as much as possible. Traffic (traffic jams) data is provided by specialized services and services, via the GPRS protocol or from the radio on the air via the RDS channels of the FM band.

SPACE IMAGES IN NAVIGATORS

Any navigational maps become outdated quickly enough. The advent of ultra-high spatial resolution space imagery (currently, the WorldView-1, WorldView-2, GeoEye-1 spacecraft provide up to 50 cm resolution) provide cartography with a powerful tool for updating the map content. However, after updating the map and before its release and the possibility of "loading" into the navigation device, a lot of time passes. Space images provide an opportunity to immediately receive the most relevant information in the navigator.

Of particular interest from the point of view of using space images are the so-called. LBS services. LBS (Location-based service) is a service based on determining the location of a mobile phone. Taking into account the widespread development of mobile communications and the expansion of services provided by cellular operators, it is difficult to overestimate the potential of the LBS services market. LBSs do not necessarily use GPS technology to determine their location. Location can also be determined using base stations of GSM and UMT cellular networks.

rice. 6 Space shot in Nokia mobile phone

Manufacturers of mobile phones and navigation devices, providing LBS services, pay more and more attention to space imagery. Let's take as an example Nokia (Finland), which signed an agreement in 2009 with DigitalGlobe, operator of super-high-resolution satellites WorldView-1, WorldView-2 and QuickBird, to provide Ovi Maps users with access to space imagery (note that Ovi - Nokia's new brand for Internet services).

In addition to clarity when navigating urban areas (Fig. 8), it is very useful to have a background in the form of satellite images, while traveling through an underexplored territory for which there are no fresh and detailed maps. Ovi Maps can be downloaded to almost all Nokia devices.

The integration of ultra-high resolution satellite imagery into LBS services makes it possible to increase their functionality by an order of magnitude.

One of the promising possibilities of using Earth remote sensing data from space is the creation of three-dimensional models based on them. Three-dimensional maps are highly visual, and allow you to better navigate, especially in urban areas (Fig. 9).

rice. 7 3D navigation chart

In conclusion, let us note the great promise of using ultra-high resolution orthorectified images in satellite navigators and LBS services. The Sovzond company produces ORTOREGION and ORTO10 products, which are based on orthorectified images from the ALOS (ORTOREGION) and WorldView-1, WorldView-2 (ORTO10) spacecraft. Orthorectification of individual scenes is performed using the rational polynomial coefficients (RPC) method without using ground control points, which significantly reduces the cost of work. The studies have shown that, according to their characteristics, the ORTOREGION and ORTO10 products may well serve as a basis for updating navigation maps, respectively, at 1:25 000 and 1:10 000 scales. Orthophotomosaics, which are actually photo maps, supplemented with signatures, can also be directly loaded into navigators.

The integration of high-resolution satellite imagery into navigation systems and LBS-services allows an order of magnitude increase in their functionality, convenience and efficiency of use.

The word "satellite" in the meaning of an aircraft appeared in our language thanks to Fyodor Mikhailovich Dostoevsky, who reasoned about "what will become in space with an ax? .. If it gets far away, then I think it will start to fly around the Earth, without knowing why, in the form of a satellite ... ". What prompted the writer to such reasoning is difficult to say today, but a century later - at the beginning of October 1957 - not even an ax began to fly around our planet, but a device that was most complicated at that time, which became the first artificial satellite sent into space with very specific goals. ... And others followed him.

Features of "behavior"

Today, everyone has long been accustomed to satellites - violators of the calm picture of the night sky. Created at factories and launched into orbit, they continue to "circle" for the good of mankind, remaining invariably interesting only to a narrow circle of specialists. What are artificial satellites and what benefit does a person get from them?

As you know, one of the main conditions for a satellite to enter orbit is its speed - 7.9 km / s for low-orbit satellites. It is at this speed that dynamic equilibrium occurs and the centrifugal force balances the force of gravity. In other words, the satellite flies so fast that it does not have time to fall to the earth's surface, since the Earth literally leaves from under its feet due to the fact that it is round. The higher the initial velocity reported to the satellite, the higher its orbit will be. However, with distance from the Earth, the speed in a circular orbit decreases and geostationary satellites move in their orbits at a speed of only 2.5 km / s. When solving the problem of a long and even eternal existence of a spacecraft (SC) in a near-earth orbit, it is necessary to raise it to an ever greater height. It is worth noting that the Earth's atmosphere also significantly affects the spacecraft motion: even being super-rarefied at altitudes over 100 km from sea level (the conditional boundary of the atmosphere), it noticeably slows them down. So, over time, all spacecraft lose their flight altitude and the duration of their stay in orbit directly depends on this altitude.

From the Earth, satellites are visible only at night and at those times when they are illuminated by the Sun, that is, they do not fall into the region of the earth's shadow. The need for all of the above factors to coincide leads to the fact that the duration of observation of most LEO satellites is, on average, 10 minutes before entering and the same amount after leaving the Earth's shadow. If desired, terrestrial observers can systematize satellites by brightness (the International Space Station (ISS) is in the first place here - its brightness is approaching the first magnitude), by the frequency of blinking (determined by forced or specially specified rotation), in the direction of movement (through the pole or in the other direction). The conditions for observing satellites are significantly affected by the color of its coverage, the presence and range of solar panels, as well as the flight altitude - the higher it is, the slower the satellite moves and the less bright and noticeable it becomes.

The high altitude of flight (the minimum distance to the Earth is 180-200 km) conceals the size of even such relatively large spacecraft as the Mir orbital complexes (de-orbited in 2001) or the ISS - all of them are visible as luminous points, more or less brightness. With a simple eye, with rare exceptions, it is impossible to identify a satellite. For the purpose of accurate identification of spacecraft, various optical means are used - from binoculars to telescopes, which is not always accessible to a simple observer, as well as calculations of their trajectories. The Internet helps the amateur astronomer to identify individual spacecraft, where information on the location of satellites in low-Earth orbit is published. In particular, anyone can enter the NASA website, which displays the current location of the ISS in real time.

As for the practical use of satellites, starting from the very first launches, they immediately began to solve specific problems. So, the flight of the first satellite was used to study the Earth's magnetic field from space, and its radio signal carried data on the temperature inside the sealed satellite body. Since the launch of a spacecraft is a rather expensive pleasure, and besides, it is very difficult to implement, then several tasks are assigned to each of the launches at once.

First of all, technological problems are solved: development of new designs, control systems, data transmission, and the like. The experience gained makes it possible to create the next copies of satellites with more advanced ones and gradually move on to solving complicated target tasks that justify the costs of their creation. After all, the ultimate goal of this production, like any other, is to make a profit (commercial launches) or the most efficient use of satellites during operation for defense purposes, solving geopolitical and many other tasks.

It should be recalled that astronautics as a whole was born as a result of the military-political confrontation between the USSR and the USA. And, of course, as soon as the first satellite appeared, the defense departments of both countries, having established control over outer space, have since then kept a constant record of all objects in the immediate vicinity of the Earth. So, probably, only they know the exact number of spacecraft, one way or another functioning at the moment. At the same time, not only the spacecraft themselves are tracked, but also the last stages of the rockets, transition compartments and other elements that delivered them into orbit. That is, strictly speaking, a satellite is considered not only that which has "intelligence" - its own control, observation and communication system - but also a simple bolt that separated from the spacecraft during the next phase of the flight.

According to the catalog of the US Space Command, as of December 31, 2003, there were 28,140 such satellites in low-earth orbit, and their number is steadily growing (objects larger than 10 cm are taken into account). Over time, due to natural reasons, some of the satellites fall to Earth in the form of fused remnants, but many remain in orbits for decades. When spacecraft work out their resource and cease to obey commands from the Earth, while continuing to fly, it becomes not only cramped in near-Earth space, but sometimes even dangerous. Therefore, when launching a new spacecraft into orbit, in order to avoid collisions and disasters, it is necessary to constantly be aware of where the “old” one is.

The classification of spacecraft is a rather laborious task, since each spacecraft is unique, and the range of tasks solved by new spacecraft is constantly expanding. However, if we consider spacecraft from the point of view of practical use, then we can distinguish the main categories determined by their intended purpose. The most in demand today are communication satellites, navigation, remote sensing of the Earth and scientific. Military satellites and reconnaissance satellites constitute a separate class, but in essence they solve the same problems as their "peaceful" counterparts.

Communication satellites

Signalers were among the first to benefit from the launch of satellites in practice. The launching of transponder satellites into near-earth orbit made it possible to quickly solve the problem of stable all-weather communication in most of the inhabited territory. The first commercial satellite was the communications satellite Echo-2, launched by the United States in 1964 and which made it possible to organize the transmission of television programs from America to Europe without using cable communication lines.

At the same time, its own communications satellite "Molniya-1" was created in the Soviet Union. After the deployment of the ground network of Orbita stations, all regions of our large country gained access to Central Television, and in addition, the problem of organizing reliable and high-quality telephone communications was resolved. The Molniya communication satellites were deployed in highly elliptical orbits with an apogee of 39,000 km. For the purpose of continuous broadcasting, a whole constellation of Molniya satellites was deployed, flying in different orbital planes. Ground stations of the Orbit network were equipped with rather large antennas, which, with the help of servo drives, tracked the movement of the satellite in orbit, periodically switching to the one that was in the field of view. Over time, in the process of improving the element base and improving the technical parameters of onboard and ground systems, several generations of such satellites have changed. But to this day constellations of satellites of the Molniya-3 family provide information transmission throughout Russia and beyond.

The creation of powerful launch vehicles of the "Proton" and "Delta" types made it possible to ensure the delivery of communication satellites into a geostationary circular orbit. Its peculiarity lies in the fact that at an altitude of 35,800 km, the angular velocity of rotation of the satellite around the Earth is equal to the angular velocity of rotation of the Earth itself. Therefore, a satellite in such an orbit in the plane of the earth's equator seems to hang over one point, and 3 geostationary satellites located at an angle of 120 ° provide an overview of the entire surface of the Earth, with the exception of only circumpolar regions. Since the task of maintaining its given position in orbit is assigned to the satellite itself, the use of geostationary spacecraft has made it possible to significantly simplify ground-based means of receiving and transmitting information. The need to supply the antennas with drives has disappeared - they have become static, and to organize a communication channel, it is enough to set them only once, during the initial setup. As a result, the terrestrial network of users was significantly expanded, and information began to flow directly to the consumer. Evidence of this is the multitude of parabolic dish antennas located on residential buildings both in large cities and in rural areas.

At first, when space was "available" only to the USSR and the USA, each of the countries cared exclusively about meeting their own needs and ambitions, but over time it became clear that everyone needed satellites, and as a result, international projects gradually began to appear. One of them is the publicly accessible global communications system INMARSAT, created in the late 1970s. Its main purpose was to provide ships with stable communications while on the high seas and coordinate actions during rescue operations. Now mobile communication through the INMARSAT satellite communication system is provided by means of a portable terminal the size of a small case. When you open the lid of the "suitcase" with a flat antenna mounted in it and point this antenna at the supposed location of the satellite, two-way voice communication is established, and data exchange occurs at a speed of up to 64 kilobits per second. Moreover, today four modern satellites provide communication not only at sea, but also on land, covering a huge territory stretching from the Northern to the Southern Arctic Circle.

Further miniaturization of communication facilities and the use of high-performance antennas on spacecraft led to the fact that the satellite phone acquired a "pocket" format, not much different from the usual cellular one.

In the 1990s, the deployment of several mobile personal satellite communications systems began almost simultaneously. First there were low-orbit ones - IRIDIUM (Iridium) and GLOBAL STAR (Global Star), and then geostationary - THURAYA (Thuraya).

The "Thuraya" satellite communications system has 2 geostationary satellites in its composition so far, allowing communication in most of the African continent, on the Arabian Peninsula, in the Middle East and in Europe.

The Iridium and Global Star systems, which are similar in structure, use constellations of a large number of LEO satellites. Spacecraft alternately fly over the subscriber, replacing each other, thereby maintaining continuous communication.

The "Iridium" includes 66 satellites rotating in circular orbits (height 780 km from the Earth's surface, inclination 86.4 °), located in six orbital planes, 11 vehicles each. This system provides 100% coverage of our planet.

Global Star includes 48 satellites flying in eight orbital planes (altitude 1,414 km from the Earth's surface, inclination 52 °), 6 vehicles each, providing 80% coverage, excluding circumpolar regions.

There is a fundamental difference between these two satellite communication systems. In Iridium, a telephone signal arriving at a satellite from Earth is transmitted through a chain to the next satellite until it reaches the one that is currently in the visibility range of one of the ground receiving stations (gateway stations). This arrangement makes it possible to start operating it as soon as possible after the deployment of the orbital component at a minimum cost of creating a ground infrastructure. In "Global Star" broadcasting of a signal from satellite to satellite is not provided, therefore this system requires a denser network of ground receiving stations. And since they are absent in a number of regions of the planet, there is no continuous global coverage.

The practical benefits of the use of personal satellite communications have become obvious today. Thus, in the process of climbing Mount Everest in June 2004, Russian climbers had the opportunity to use telephone communication through the Iridium, which significantly reduced the intensity of the anxiety of all those who followed the fate of climbers during this difficult and dangerous event.

An emergency with the crew of the SoyuzTM-1 spacecraft in May 2003, when, after returning to Earth, the rescuers could not find the cosmonauts in the Kazakh steppe for 3 hours, also prompted the ISS program managers to provide the cosmonauts with the Iridium satellite phone.

Navigation satellites

Another achievement of modern astronautics is the global positioning system receiver. The creation of the currently existing satellite global positioning systems - the American GPS (NAVSTAR) and the Russian "GLONASS" - began 40 years ago, during the Cold War, to accurately determine the coordinates of ballistic missiles. For these purposes, as a supplement to satellites - rocket launch recorders, a system of navigation satellites was deployed in space, the task of which was to communicate their exact coordinates in space. Having received the necessary data from several satellites simultaneously, the navigation receiver determined its own position.

The “protracted” peacetime forced the owners of the systems to start sharing information with civilian consumers, first in the air and on the water, and then on land, although it reserved the right to coarse the binding of navigation parameters in certain “special” periods. This is how military systems became civilian.

Various types and modifications of GPS receivers are widely used in marine and air vehicles, in mobile and satellite communication systems. Moreover, the GPS receiver, like the transmitter of the Cospas-Sarsat system, is a must-have equipment for any floating craft going to the open sea. The cargo spacecraft ATV, which is to fly to the ISS in 2005, being created by the European Space Agency, will also correct its trajectory with the station according to GPS and GLONASS data.

Both navigation satellite systems are approximately the same. GPS has 24 satellites, located in circular orbits of 4 in six orbital planes (altitude 20,000 km from the Earth's surface, inclination 52 °), as well as 5 spare vehicles. GLONASS also has 24 satellites, 8 each in three planes (altitude 19,000 km from the Earth's surface, inclination 65 °). In order for the navigation systems to work with the required accuracy, atomic clocks are installed on the satellites, information is regularly transmitted from the Earth, specifying the nature of the movement of each of them in orbit, as well as the conditions for the propagation of radio waves.

Despite the seeming complexity and scale of the global positioning system, a compact GPS receiver today can be purchased by anyone. According to signals from satellites, this device allows not only to determine the location of a person with an accuracy of 5-10 meters, but also to provide him with all the necessary data: geographical coordinates indicating the location on the map, current world time, speed of movement, altitude, position of the sides light, as well as a number of service functions derived from primary information.

The advantages of space navigation systems are so indisputable that the United Europe, despite the enormous costs, plans to create its own navigation system GALILEO ("Galileo"). China also plans to deploy a system of its navigation satellites.

Earth remote sensing satellites

The use of miniature GPS receivers has made it possible to significantly improve the operation of another category of spacecraft - the so-called Earth remote sensing satellites (ERS). If earlier images of the Earth taken from space were difficult enough to associate with certain geographic points, now this process does not present any problems. And since our planet is constantly changing, its photos from space, never repeated, will always be in demand, providing irreplaceable information for studying the most diverse aspects of life on earth.

Remote sensing satellites have a fairly large number, and nevertheless, their group is constantly replenished with new, more and more advanced devices. Modern remote sensing satellites, unlike those that operated in the 1960s and 1970s, do not need to return to Earth the films captured in space in special capsules - they are equipped with super-light optical telescopes and miniature photodetectors based on CCD matrices, as well as high-speed data lines with a bandwidth of hundreds of megabits per second. In addition to the efficiency of data acquisition, it becomes possible to fully automate the processing of the received images on Earth. Digitized information is no longer just an image, but the most valuable information for ecologists, foresters, land surveyors and many other interested structures.

In particular, multispectral photographs taken in the spring make it possible to predict the yield based on the moisture reserve in the soil, during the growing season of plants - to detect the places where narcotic crops are grown and take timely measures to destroy them.

In addition, current commercial systems for selling video images of the Earth's surface (photographs) to consumers must be taken into account. The first such systems were first the US civilian satellite constellation LANDSAT, and then the French SPOT. Under certain restrictions and in accordance with certain prices, consumers around the world can acquire images of areas of interest on the Earth with a resolution of 30 and 10 meters. The current, much more advanced civilian satellites - ICONOS-2, QUICK BIRD-2 (USA) and EROS-AI (Israel-USA) - after the removal of restrictions by the American government, allow you to buy photographs of the earth's surface with a resolution of up to 0.5 meters - in panchromatic mode and up to 1 meter - in multispectral mode.

Close to the remote sensing satellites are meteorological spacecraft. The development of their network in near-earth orbits has significantly increased the reliability of weather forecasting and made it possible to do without extensive networks of ground-based weather stations. And the news releases published today all over the world, accompanied by animated images of cyclones, paths of cloudiness, typhoons and other phenomena, which are created on the basis of data from meteorological satellites, allow each of us to personally be convinced of the reality of natural processes occurring on Earth.

Satellites - "scientists"

By and large, each of the artificial satellites is an instrument of cognition of the surrounding world taken out of the Earth. Scientific satellites, on the other hand, can be called a kind of testing grounds for testing new ideas and designs and obtaining unique information that cannot be obtained in any other way.

In the mid-1980s, NASA adopted a program to create four astronomical observatories in space. With some delays or other, all four telescopes were launched into orbit. The first to start its work was "HUBBL" (1990), designed to study the Universe in the visible range of wavelengths, followed by "KOMPTON" (1991), which studied space using gamma rays, the third was "CHANDRA" (1999 ), which used X-rays, and completed this extensive program SPITZER (2003), which accounted for the infrared range. All four observatories were named after prominent American scientists.

HUBBL, which has been operating in near-Earth orbit for the 15th year, delivers unique images of distant stars and galaxies to Earth. For such a long service life, the telescope was repaired several times during shuttle flights, but after the sinking of Columbia on February 1, 2003, the launches of space shuttles were suspended. It is planned that the HUBBL will remain in orbit until 2010, after which it will be destroyed, having exhausted its resource. KOMPTON, which transmitted images of gamma-ray sources to Earth, ceased to exist in 1999. CHANDRA continues to supply information about X-ray sources on a regular basis. All three of these telescopes were designed by scientists to work in highly elliptical orbits in order to reduce the influence of the Earth's magnetosphere on them.

As for "SPITZER", which is capable of capturing the weakest thermal radiation emanating from cold distant objects, unlike its counterparts revolving around our planet, it is in solar orbit, gradually moving away from the Earth by 7 ° per year. In order to perceive extremely weak thermal signals emanating from the depths of space, SPITZER cools its sensors to a temperature that exceeds absolute zero by only 3 °.

For scientific purposes, not only bulky and complex scientific laboratories are launched into space, but also small spherical satellites equipped with glass windows and containing corner reflectors inside. The parameters of the flight paths of such miniature satellites are tracked with a high degree of accuracy using laser radiation directed at them, which makes it possible to obtain information about the slightest changes in the state of the Earth's gravitational field.

Immediate prospects

Space engineering, which received such rapid development at the end of the 20th century, does not stop progressing for a single year. Satellites, which seemed to be the height of technical thought some 5-10 years ago, are replacing new generations of spacecraft in orbit. And although the evolution of artificial earth satellites is becoming more and more fleeting, looking into the near future, one can try to see the main prospects for the development of unmanned astronautics.

X-ray and optical telescopes flying in space have already presented scientists with many discoveries. Now, entire orbital complexes equipped with these devices are being prepared for launch. Such systems will make it possible to conduct a massive study of the stars of our Galaxy for the presence of planets in them.

It's no secret that modern earth-based radio telescopes receive pictures of the starry sky with a resolution that is orders of magnitude higher than that achieved in the optical range. Today it is time for this kind of research instruments to be launched into space. These radio telescopes will be launched into high elliptical orbits with a maximum distance of 350 thousand km from the Earth, which will make it possible to improve the quality of the radio emission of the starry sky obtained with their help by at least 100 times.

The day is not far off when factories for the production of highly pure crystals will be built in space. And this applies not only to biocrystalline structures, so necessary for medicine, but also materials for the semiconductor and laser industries. It is unlikely that these will be satellites - here you will most likely need visited or robotic complexes, as well as transport ships docked to them, delivering the initial products and bringing the fruits of extraterrestrial technology to Earth.

The colonization of other planets is not far off. On such long flights, you cannot do without creating a closed ecosystem. And biological satellites (flying greenhouses), simulating long-distance space flights, will appear in near-earth orbit in the very near future.

One of the most fantastic tasks, while already today from a technical point of view is absolutely real, is the creation of a space system for global navigation and observation of the earth's surface with an accuracy of centimeters. This positioning accuracy will find applications in a wide variety of areas of life. First of all, seismologists need this, hoping, by tracking the slightest vibrations of the earth's crust, to learn how to predict earthquakes.

At the moment, the most economical way to launch satellites into orbit are disposable launch vehicles, and the closer to the equator the cosmodrome is, the cheaper the launch is and the larger the payload to be launched into space. And although floating and aircraft launchers have already been created and are successfully functioning, the well-developed infrastructure around the cosmodrome will be the basis for the successful activities of earthlings in the development of near-earth space for a long time to come.

Alexander Spirin, Maria Pobedinskaya

The editors are grateful to Alexander Kuznetsov for his help in preparing the material.

orbital constellation;

development work;

space rocket;

rocket and space technology;

operator's workplace;

launch vehicle;

root mean square error;

technical task;

feasibility study;

federal space program;

digital elevation model;

emergency.

Introduction

The content of the studies, the results of which are presented in this review, are:

The creation of corporate space systems and complexes should be based on a modern element base and the latest design solutions, and the nomenclature and quality of the data obtained should correspond to the world level.

1 Review of space programs for remote sensing of foreign countries

1.1 US space program

1.1.1 US Space Policy Framework

The main ideas of the new space policy:

The main goals of the US space policy are:

1.1.2 Statement of Strategic Intentions of the US National Geospatial Intelligence System

Figure 1 - Space image - raster image

Figure 2 - Identification of targets and objects

Figure 3 - Displaying the operational situation in real time

1.1.3 Space military surveillance program

1.1.4 US Commercial Space Program

Figure 4 - Spacecraft WorldView-1

Figure 5 - GeoEye-1 spacecraft

The next logical step in the development of the ERS space assets market is the launch of a spacecraft with ultra-high resolution (up to 0.25 m). Previously, images with this resolution were provided only by military satellites of the United States and the USSR.

So far, the main competing companies in the remote sensing market from Europe, Russia, Japan, Israel and India have no plans to create ultra-high resolution remote sensing satellites. Therefore, the launches of such devices in the United States will lead to further market development and the strengthening of the positions of American companies - operators of Earth remote sensing systems.

1.2 Space programs of European countries

1.2.1 France

The space segment of the SPOT system currently consists of four spacecraft (SPOT 2, -4, -5 and -6). The ground segment includes the SC control and operation center, a network of information receiving stations and data processing and distribution centers.

Figure 6 - SPOT 5 spacecraft

1.2.2 Germany

Figure 7 - Satellites TerraSAR-X and Tandem-X

Figure 8 - Architecture of the orbital segment of the SAR-Lupe system

1.2.3 Italy

The Italian space exploration program is based on the use of US launch vehicles (Scout), the European Organization for the Development of Launch Vehicles (Europe 1) and the European Space Agency (Ariane).

1.2.4 UK

Figure 9 - Image with a resolution of 2.8 m, received by the TOPSAT-1 minisatellite

1.2.5 Spain

Spain is also participating in the creation of a global European defense satellite surveillance system.

1.3 Space programs of other countries

1.3.1 Japan

Figure 10 - 3D-model of the territory of Gujarat, built according to Cartosat-1 data

On January 10, 2007, the Cartosat-2 satellite was launched, with the help of which India entered the meter-resolution data market. Cartosat-2 is a panchromatic camera remote sensing satellite for cartography. The camera is designed for photography with a spatial resolution of one meter and a swath width of 10 km. The spacecraft has a sun-synchronous polar orbit with an altitude of 630 km.

India is ready to distribute satellite images of meter resolution, obtained with the help of Cartosat-2, at prices below market prices and in the future plans to launch a new spacecraft with a spatial resolution of up to 0.5 meters.

1.3.2 Israel

1.3.3 China

Figure 11 - SC CBERS-01

On September 19, 2007, the third Chinese-Brazilian ERS satellite CBERS-2B was launched in China. The satellite was launched into a morning sun-synchronous orbit with an altitude of 748x769 km, an inclination of 98.54 degrees, the time of crossing the equator is 10:30.

1.3.4 Korea

1.3.5 Canada

Canada in 1990 created the Canadian Space Agency, under the leadership of which work is carried out on the rocket and space theme.

The satellite, originally designed for 5 years of operation in space, has doubled its design time and continues to transmit high-quality images. For 10 years of flawless operation, RADARSAT-1 has surveyed territories with a total area of ​​58 billion square meters. km, which is two orders of magnitude larger than the surface area of ​​the Earth. The system reliability was 96%. The largest of the 600 consumers of RADARSAT-1 information is Ice Reconnaissance Canada, which receives 3,800 radar images annually with a time delay of less than 90 minutes after acquisition.

Figure 12 - RADARSAT in space through the eyes of an artist

The Canadian Space Agency has signed a contract with MacDonald, Dettwiler and Associates (MDA) to conduct a project to create a second generation of satellites for remote sensing of the Earth's surface using Radarsat-2. The Radarsat-2 satellite provides images with a resolution of 3 m per pixel.

1.3.6 Australia

Australia actively cooperates with a number of countries in the field of space exploration. Australian firms are also developing a microsatellite with South Korea to collect environmental data in rural areas in the Asia-Pacific region. According to the director of the CRCSS center, the project will cost $ 20-30 million. Australia's cooperation with Russia opens up great prospects.

1.3.7 Other countries

Recently, Taiwan's National Space Agency NSPO announced plans to develop the first spacecraft by the national industry. The project, called Argo, is aimed at creating a small satellite for Earth remote sensing (ERS) using high-resolution optical equipment.

According to NSPO, in the course of work on the Argo project, a space platform has already been developed, in the control system of which the new LEON-3 processor will be used for the first time. All software for onboard systems and ground flight control center is supposed to be created in Taiwan. The estimated life of the satellite will be 7 years.

1.4 Space programs of the CIS countries

1.4.1 Belarus

Table 1. Main characteristics of the Kanopus-V and BKA spacecraft

Spacecraft size, m × m

Spacecraft mass

Payload mass, kg

Orbit:

altitude, km

inclination, hail

period of circulation, min

time of crossing the equator, hour

Re-observation period, days

Average daily power, W

Active life, years

Spacecraft "Kanopus-V" and BKA are designed to solve the following tasks:

- highly operational observation.

1.4.2 Ukraine

As for high-resolution spacecraft better than 10 m, it is also advisable to create them on a cooperative basis with interested foreign partners and owners of similar systems. When creating promising spacecraft, special attention should be paid to increasing the information capabilities of the system. In this regard, Ukraine has a number of original developments.

1.4.3 Kazakhstan

Representatives of the research organizations and production and implementation structures of Kazakhstan, Russia and foreign countries involved in the implementation of the Kazakh space program believe that satellite communications and Earth remote sensing systems should become the priority direction of development of space activities in Kazakhstan at the moment.

2 Russian space program

2.1 Main provisions of the Federal Space Program of Russia for 2006-2015

The main objectives of the Program are:

Terms and stages of the Program implementation - 2006 - 2015.

At the first stage (until 2010), in terms of remote sensing of the Earth, the following are created:

The priority areas of space activities contributing to the achievement of strategic goals are:

Program activities include activities funded from the budget and activities carried out with funds invested in space activities by non-governmental customers.

Activities financed from budgetary funds include the activities provided for in the following sections:

section I - "Research and development work";

During the implementation of the Program, the following results will be achieved:

b) the frequency of updating the data of hydrometeorological observation has been increased to 3 hours for medium-altitude spacecraft and to a real time scale for geostationary spacecraft, which will provide:

e) a space complex with a small-sized spacecraft was created with an increased accuracy of determining the coordinates of objects in distress, the promptness of receiving emergency messages up to 10 seconds and an accuracy of determining the location of objects in distress up to 100 m were ensured.

An assessment of the magnitude of the economic effect from the results of space activities in the socio-economic and scientific spheres shows that as a result of the implementation of the Program, the generalized economic effect in the period 2006-2015 is projected at the level of 500 billion rubles in 2005 prices.

2.2 Analysis of ERS space systems.

Figure 13 - ERS spacecraft orbital constellation for the period 2006-2015

In fact, the main ERS spacecraft developed in the period up to 2015 will be the Kanopus-V spacecraft for operational monitoring of man-made and natural emergencies and the Resurs-P spacecraft for operational optoelectronic observation.

SC "Kanopus-V" No. 1, which was launched on July 22, 2012, includes:

The Resource-P complex is a continuation of the domestic high-resolution remote sensing equipment used in the interests of the social and economic development of the Russian Federation. It is designed to solve the following tasks:

- Subsystem "Arktika-MS2" of four spacecraft to provide mobile government communications, air traffic control and relay of navigation signals (developed by JSC "ISS named after MF Reshetnev").

2.3 Development of a ground-based complex for receiving, processing, storing and distributing ERS CI

As noted in the FKP-2015, the ground space infrastructure, including cosmodromes, ground control facilities, information receiving points and an experimental base for ground testing of rocket and space technology products, needs to be modernized and retrofitted with new equipment.

The functional diagram of the integrated remote sensing satellite system is shown in Figure 14.

Figure 14 - Integrated ERS satellite system

Thus, the ministries and departments-consumers of CI ERS, on the one hand, and the Federal Space Agency, on the other hand, are interested in ensuring the coordination of the activities of all NKPOR centers and stations created by different departments and organizations and establishing their coordinated functioning and interaction according to uniform rules. convenient for all parts of the NCCOR and consumers.

3 Analysis of the "Concept for the development of the Russian space system for remote sensing of the Earth for the period up to 2025"

An important section of the Concept is the proposals that increase the efficiency of using space information in Russia.

The main problems that determine the efficiency of using space information in Russia are:

This approach is promising, since as the development of the national geoinformatics market accelerates, there will be a steady demand for geospatial data, which can be replenished with domestic remote sensing systems as they emerge and develop. The problems of the development of the remote sensing industry are not solved in one day immediately after the launch of a new satellite; a rather long stage of the formation of a stable demand for remote sensing data is required.

9. To develop and put into operation ground and aviation means of validation of the results of thematic processing of space information.

4 Feasibility study of funding principles for the creation of remote sensing space systems

Conclusion

The studies performed allow us to draw the following conclusions:

3 A. Kucheiko. New US policy in the field of commercial remote sensing means. Cosmonautics news, no. 6, 2003

4 V. Chularis. US National Outer Space Policy. Foreign military review No. 1, 2007

6 V. Chularis. Geographic information support of the US Armed Forces. Foreign military review, No. 10, 2005

7 US space reconnaissance tasked with new tasks. Science, 03.02.06

8 The United States has created in orbit the largest ever constellation of reconnaissance satellites in history. News of Science. 03.02.2006

9 A. Andronov. Satellites available to terrorists. "Independent Military Review", 1999

10 V. Ivanchenko. The Sharp Eye Iconos. Magazine "COMPUTERRA", 06.09.2000

11 M. Rakhmanov. Satellite intelligence: new development trends. C.NEWS High Technology Edition 2006

12 A. Kopik. A new commercial spy has been launched. "News of Cosmonautics", No. 6, 2003.

13 M. Rakhmanov. Satellite sensing: change is inevitable. C.NEWS High Technology Edition 2006

16 Yu.B. Baranov. Remote sensing data market in Russia. Journal "Spatial Data", No. 5, 2005

17 French intelligence rushes into space. Science, 27.12.04.

18 Radar imagery: Germany takes the lead. Science, 20.03.06.

19 Maxim Rakhmanov “Germany launches a space espionage system”, Science, CNews, 2003.

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28 Radar satellite: Canada keeps Russia from going blind. Science, 2005

the leading position of the United States as a world leader in the development and use of Earth remote sensing (ERS) systems. The main efforts of state regulation of the remote sensing industry in the United States are aimed at encouraging the development of market

mechanisms.

The fundamental document in this area is the directive on space policy on the use of commercial remote sensing systems, approved by the President of the United States

March 1994, which outlined the fundamentals of the US policy in the field of access of foreign customers to the resources of American Earth remote sensing systems.

The new policy aims to further strengthen the leadership position in

the world of American companies and covers the following areas of activity:

− licensing of the activity and functioning of the remote sensing system;

− using the resources of the remote sensing system in the interests of defense, intelligence and

other US government departments;

− access of foreign customers (government and commercial) to ERS resources, export of ERS technologies and materials;

− intergovernmental cooperation in the field of military and commercial space imagery.

The main goal of the policy is to strengthen and protect the national security of the United States and the interests of the country in the international arena by strengthening the leading position in

areas of CS ERS and the development of national industry. The objectives of the policy are to stimulate economic growth, protect the environment and strengthen

scientific and technological excellence.

The new directive also affects the commercialization of sensing systems.

On a non-commercial basis, according to experts, remote sensing technologies will not only fail to develop, but will also throw the United States (like any other country) far back from the leading positions in the world. Space imagery materials, according to the US government,

become demanded by government departments for their needs with products of remote sensing systems obtained on a commercial basis. In this case, one of the

the main goals are to relieve the National Intelligence Community of the large volume of requests for these products from various US departments. The second, but no less important task of the new government policy in the field of space is the commercialization of remote sensing systems in order to further strengthen the world's leading

the provisions of the American companies - operators of space sensing systems. The directive determines the procedure for licensing the activities of the remote sensing system in

interests of the Ministry of Defense, intelligence and other departments, for example, the State Department, etc. And it also sets certain restrictions for foreign customers of products

remote sensing systems and the export of technologies and materials for it and defines the basis for intergovernmental cooperation in the field of military and commercial types

The steps taken by the US government are strengthening and protecting national security and creating an enabling environment for the country in the international arena by strengthening America's leading position in the field of

Remote sensing and development of our own industry. To this end, the government of the country

immense powers have been granted to the US National Cartography and Imaging Information Administration - NIMA, which is a structural subdivision of the US intelligence community. NIMA is functionally responsible for the collection, distribution of species information received from the remote sensing space systems among

government departments and foreign consumers, receiving and distributing

which is produced only with the approval of the US Department of State. The Department of Commerce and NASA are charged with coordinating requests for Earth remote sensing products in the commercial sector across areas. This provides for the use of the same species information by different departments interested in the same survey areas.

Civilian needs in the field of remote sensing are determined by the ministries of commerce,

Interior and Space Agency NASA. They also allocate appropriate funds for the implementation of projects in this area. Assistance in implementation

civil government remote sensing programs are provided by NIMA. This

the organization is also the lead in the preparation of action plans for the implementation of the new space policy, in the development of which, in addition to NIMA, the ministers of defense, trade, the State Department and the director of central intelligence (concurrently and director of the CIA) are involved.

Geoinnovation agency "Innoter"

It is characteristic that these issues are solved by law, in the form of discussion and adoption of laws. It is taken into account that such government means of remote sensing, such as Landsat,

Terra, Aqua and others will be used to solve defense and reconnaissance tasks when it becomes unprofitable for the operator to obtain information using commercial remote sensing systems. NIMA creates all the necessary conditions for the US industry to gain a competitive advantage over others

countries. The US government guarantees support for the development of the remote sensing systems market, it also reserves the right to limit sales of generic products to certain

countries in the interests of observing the leading role of the United States in spaceborne ERS. The directive stipulates that the CIA and the Ministry of Defense must monitor their inherent

methods and methods of the state of the development of remote sensing in other countries so that the US industry does not lose its leading position in the world in the markets for remote sensing means.

The US government does not prohibit its MoD from purchasing any species materials

from commercial firms. The direct benefit is clear: there is no need to launch a new one or to retarget an existing remote sensing satellite to the military area of ​​interest. And the efficiency is becoming the highest. This is what the US Department of Defense is happy to do.

thereby developing commercial structures engaged in the development and

using remote sensing systems.

The main ideas of the new space policy:

− it is legally stipulated that the resources of the American satellite remote sensing data will be in

to be used to the maximum extent for solving defense, reconnaissance

tasks, ensuring internal and international security and in the interests

civil users;

− government remote sensing systems (for example, Landsat, Terra, Aqua) will

focused on tasks that cannot be effectively solved by the operators of the CS

Remote sensing due to economic factors, interests of ensuring national

security or other reasons;

− establishment and development of long-term cooperation between

government agencies and the US aerospace industry, providing an operational mechanism for licensing activities in the field of the operation of operators of remote sensing systems and the export of technologies and materials for remote sensing;

− creating conditions that provide the US industry with a competitive advantage in the provision of remote sensing services to foreign

government and commercial customers.

Geoinnovation agency "Innoter"

The new Earth remote sensing policy is the first step of the Bush administration to revise the US space policy. It is obvious that the adoption of the document took place with the active

lobbying aerospace corporations who have embraced the new rules of the game with satisfaction. The previous policy, defined by the PDD-23 directive, contributed to the emergence and development of high-definition commercial media. The new document guarantees state support for the development of the remote sensing market, and

also establishes that new commercial projects will be developed by the industry taking into account the needs for specific products identified by civil

and defense departments.

Another important aspect is that the state becomes an "international pusher"

ERS commercial information. In the structure of sales of type information of commercial operators, defense and other government customers prevailed before.

However, the scale of purchases was relatively low and the market for space

ERS materials developed slowly. In recent years, after the appearance of a high-resolution (0.5-1 m) remote sensing spacecraft, the situation began to change. High and medium resolution commercial systems are now seen as a critical addition

military space systems, which makes it possible to increase the efficiency of order fulfillment

and the performance of the integrated system as a whole, to delimit functions and expand the circle of users of specific information.

Over the past 5-7 years, species imaging using commercial spacecraft has become an important source of up-to-date and high-quality species information due to

for a number of reasons:

− the resource of military surveillance systems is limited due to the expansion of the range of tasks and the number of consumers, as a result of which the efficiency of solving the tasks of survey shooting has decreased;

− commercial species production of medium and low resolution has become more accessible,

by virtue of the introduction of the principles of direct broadcasting and the growth of the supply of services on the international market;

− The market for high-resolution images (up to 1 m and better) has grown significantly, and the number of operators of commercial camera systems has increased, which has led to increased competition and reduced service costs;

− commercial specific products do not have a secrecy stamp, therefore, they are subject to wide distribution among the lower levels of the Armed Forces, the command of the allied forces, other departments (the Ministry of Foreign Affairs, the Ministry of Emergency Situations, the border service) and

even the media.

Geoinnovation agency "Innoter"

On August 31, 2006, US President George W. Bush approved the concept of the US National Space Policy, which presents

fundamental principles, goals, objectives and directions of activity of the American military-political leadership, federal ministries and departments, as well as commercial structures for the use of outer space in national interests. This document replaced the 1996 presidential directive of the same name.

The release of the "national space policy" was due to the increased importance of space systems in ensuring the national security of the United States, and

also the need to bring the implemented space policy in accordance with the new conditions of the situation.

The implementation of space programs has been declared a priority area of ​​activity. At the same time, the American military-political leadership will

adhere to a number of fundamental principles below:

− all countries have the right to free use of outer space for peaceful purposes, allowing the United States to carry out military and intelligence activities in the national interests;

− any claims are rejected any country for the sole use of outer space, celestial bodies or their parts, as well as restriction of the rights of the United States to such activities;

− The White House seeks to cooperate with the VPR of other states within the framework of

the peaceful uses of outer space in order to expand the opportunities and achieve greater results in space exploration;

− US spacecraft must operate freely in outer space.

Therefore, the United States will view any interference with the functioning of its Constitutional Court as an infringement on their rights;

− CS, including ground and space components, as well as communication lines supporting their operation, are considered vital for the national interests of the country.

V In this regard, the United States will:

− defend their rights to the free use of outer space;

− to dissuade or deter other countries from acting or developing means to violate these rights;