Description NMEA protocol.
Implementation in Garmin and GlobalSat receivers
Introduction
National Marine Electronics Association (NMEA) has developed a special protocol to maintain marine navigation equipment compatibility different manufacturers. This NMEA protocol describes not only the data obtained from GPS receivers, but also measuring sonars, radars, electronic computers, barometers and other navigation devices used on marine ships. The data interface of most portable GPS receivers is implemented in accordance with the NMEA specification. Most navigation programs that provide real-time data display support and "understand" NMEA protocol. This data contains full GPS navigation measurements of the receiver - position, speed and time. All NMEA messages consist of a serial dataset separated by commas. Each separate message does not depend on others and is completely "complete". NMEA Message includes a title, a set of data provided by ASCII characters, and the "Chexumma" field to verify the reliability of the transmitted information. The header of the standard NMEA messages consists of 5 characters, of which the first two define the type of message, and the remaining three is its name. For example, all GPS NMEA messages have the "GP" prefix. Messages that are not described in the NMEA specification, but implemented in GPS receivers in accordance with the general rules, have the prefix "P", supplemented with three symbols, unique for each company. For example, the "own" NMEA messages Garmin have the prefix "PGRM", Magellan - "PMGN" Each NMEA message starts with "$" ends "\\ n" ("Row Translation") and cannot be longer than 80 characters. All data is contained in one line and separated from each other commas. Information is presented in the form of ASCII text and does not require special decoding. If the data does not fit into the selected 80 characters, they are "broken" into several NMEA messages. Such a format allows you to not limit the accuracy and number of characters in separate data fields. For example, fractional part The coordinate values \u200b\u200bcan be represented by 3 or 4 decimal signs, but this should not affect the software of the software that allocates the necessary data from the message by the field number. At the end of each NMEA, the message contains the "Chexumma" field separated from the data "*" symbol. If necessary, it can be used to verify the integrity and reliability of each received message. NMEA Protocol supports not only outgoing, but also incoming messages with which, for example, you can update or add waypoint of the route. These messages must be formed in strict accordance with the NMEA format, otherwise they will simply ignore the GPS receiver. It is worth noting that not all navigation programs and models of receivers support this mode, as the branded protocols of manufacturers - Garmin, Magellan, etc. are used to load points and routes. From the moment of creation, NMEA protocol has undergone several modifications associated with adding new fields and messages. The current version that most receivers support is version 2.3, although the description of the new version 3.0 has already been published. The full NMEA message specification is missing in free access and it cannot be officially downloaded in electronic form, its separate sections, the general description of the NMEA protocol and the most popular messages can be found on the Internet. You can officially purchase NMEA documentation on the site http://www.nmea.org/.
list of messages
NMEA Protocol describes a large list of various messages from which you can select two dozen messages that are actively used in navigation equipment. Due to the great popularity and simple data presentation, the NMEA protocol found the use of not only marine equipment, but also in geodesic, household and aviation GPS receivers.
Aam - Arrival in the Travel Point
ALM - Almanac data
APA - autopilot data "A"
APB - autopilot data "B"
BOD - Azimuth to destination
DTM - Used Datum
GGA - Fixed Solution Information
GLL - data latitude and longitude
GSA - General information about satellites
GSV - detailed information about satellites
MSK - Transfer Management Base Receiver
MSS - Base Receiver Status
RTE - VTG route information - motion and speed vector
WCV - speed data near the waypoint
WPL - travel point data
XTC - Error Deviation from Track
XTE - Measured Error Deviation from Track
ZTG - UTC time and remaining time before arriving at the destination
ZDA - date and time.
Some of the NMEA messages may contain the same data fields, or fully contain other data smaller data, NMEA messages.
GGA - Fixed Solution Information.
The most popular and most used NMEA message with information about the current fixed solution is horizontal coordinates, the height value, the number of satellites used and the type of solution.
$ GPGGA, 123519,4807.038, N, 01131.000, E, 1.08.0.9,545.4, m, 46.9, m, * 47
GGA - NMEA Sungwalk
123519 -Utc time 12:35:19
4807.038, N - latitude, 48 degrees 7.038 minutes of northern latitude
01131.000, E - longitude, 11 degrees 31.000 minutes of Eastern longitude
1 - Type Solution, Standalone Solution
08 - Number of satellites used
0.9 - Geometric Factor, HDOP
545.4, M - Height above sea level in meters
46.9, M - Height of geoid over Ellipsoid WGS 84
[Empty field] - the time has passed since the last DGPS amendment. Filled when activating DGPS mode
[Empty field] - the identification number of the base station. Filled when activated by DGPS mode.
GSA - general information About satellites.
This NMEA message contains a list of satellites used in the position of the position and the values \u200b\u200bof the geometric factors of DOPS, which determine the accuracy of the position counting. DOP parameters are determined by the geometric arrangement of satellites in the sky. The better "distributed" in the sky satellites, the less DOP and the better the accuracy of the position. The minimum value of PDOP (\u003d 1) corresponds to the situation when one satellite is strictly over the user, while the other 3 are evenly distributed around at the horizon level. PDOP value is calculated as square root From the sum of the squares of HDOP and VDOP.
$ GPGSA, A, 3,04,05,09,12,24,2,5,1.3,2.1 * 39
GSA - NMEA Title
A - selection type between 2D and 3D solutions, automatic (A-AUTO, M-MANUAL)
3 - Solution type, 3D decision (1 - no solution, 2 - 2D solution, 3 - 3D decision)
04.05 ... - PRN codes used in the counting position of satellites (12 fields)
2.5 - spatial geometric factor, PDOP
1.3 - horizontal geometric factor, HDOP
2.1 - Vertical geometric factor, VDOP
GSV - detailed information about satellites
This NMEA message contains detailed information for all GPS navigator tracked. Based on the limit of 80 characters as part of one NMEA, data can be transmitted only for 4-satellite. Accordingly, for 12 satellites, 3 GSV messages are required. The SNR field (Signal To Noise Ration) contains the values \u200b\u200bof the levels received from satellites, navigation signals. Theoretically, its value may vary from 0 to 99 and is measured in DB. In fact, the signal level lies in the range of 25 ... 35 DB. It is worth noting here that this parameter is not absolute and not suitable for comparing the sensitivity of the receivers different models and manufacturers. In GPS navigators, various algorithms for calculating the level of the received signal can be used, which leads to different results with an equal degree of sensitivity of receivers. For each visible GPS satellite, a set of information is transmitted, including signal level, elevation angle and satellite azimuth. The number of these "sets" is determined by the total number of visible satellites, the value of which is transmitted in a separate field.
$ GpgSV, 2,1,08,01,40,083,46,02,17,308,41,12,07,344,39,14,22,228,45 * 75
GSV - NMEA Title
2 - the number of GSV messages in the package
1 - Message Number in Package (from 1 to 3)
08 - the number of visible satellites
01 - satellite number
40 - elevation angle, in degrees
083 - Azimuth in degrees
46 - SNR, signal level
This NMEA message contains all sets of so-called "PVT" data. "PVT" is a generally accepted cut from "Position, Velocity, Time" (position, speed, time).
$ GPRMC, 123519, A, 4807.038, N, 01131.000, E, 022.4.084.4,230394,003.1, W * 6A
RMC - NMEA Title
123419 - UTC Time, 12:34:59
A - Status (Activative, V- Ignore)
4807.038, n - latitude, 48 degrees 07.038 minutes of northern latitude
01131.000, e - longitude, 11 degrees 31.000 minutes of Eastern longitude
022.4 - speed, in nodes
003.1, W - Magnetic Variations
GLL - data latitude and longitude
NMEA message with the value of the coordinates of latitude and longitude, and the time when this solution was calculated.
$ Gpgll, 4916.45, n, 12311.12, w, 225444, a, * 31
GLL - NMEA header
4916.46, N - latitude, 49 degrees 16.45 minutes of northern latitude
12311.12, W-longitude, 123 degrees 11.12 minutes of Western longitude
225444 - Locking time in the time scale of UTC, 22:54:44
OOD - Azimuth to destination
This NMEA message indicates azimuth to the destination point in navigation mode.
$ Gpbod, 045., T, 023., M, Dest, Start * 01
BOD - NMEA Title
045., T - True direction to the point
023., M - Magnetic direction to point
DEST - endpoint identification number
START - Identification number of the starting point
$ GPRMB, A, 0.66, L, 003,004,4917.24, N, 12309.57, W, 001.3,052.5.000.5, V * 20
RMB - NMEA Title
A - data type, (A - active, V - ignore)
0.66, L - deviation from the track. The parameter is defined in marine miles. (L -Vlevo, R-Right)
003 - Identification number of the starting point
004 - Identification number of the end point
4917.24, n - value of the latitude of the end point, 49 degrees 17.24 minutes of northern latitude
12309.57, W - the value of the longitude of the end point, 123 degrees 09.57 minutes of Western longitude
001.3 - distance to the point, in marine miles
000.5 - speed, in nodes
V - information about arrival (and - arrival, V - the point has not yet been reached)
RTE - Route Information
NMEA Message RTE Displays a list of travel points of the active route. There are two types of RTE messages. In the first case, all the route points are displayed. In the second, only the list of remaining points that have yet to be visited when moving along the route. Considering that the NMEA protocol has a limit on which the message length should not exceed 80 characters, the RTE message may consist of several lines.
$ GPRTE, 2,1, C, 0, W3IWI, DRIVWY, 32CEDR, 32-29,32BKLD, 32-I95,32-US1, BW-32, BW-198 * 69
RTE - NMEA Title
2 - Total messages for displaying a full data list
1 - Message Number from general list
c - Type RTE Messages (C - Full List of Route Points, W - List of Points that have yet to be visited)
0 - route identifier
W3IWI, DRIVWY, .. - List of waypoints
Features Garmin.
Garmin receivers support most NMEA messages containing GPS measurements, coordinates and time - GGA, GLL, GSA, GSV, RMC. As well as navigation messages - RMB, BOD
To display these messages, it is necessary to change the interface with "Garmin" to the receiver settings to "NMEA" and it is possible to set the desired speed. The same speed must be installed in the navigation program in the settings of the serial port to which the navigator is connected.
Unfortunately, USB receivers do not support NMEA protocol, limiting its settings only by the Garmin protocol
To display information entering the serial port of the computer, you can use the terminal windows programor one of the navigation programs that support this possibility.
Below is a list of NMEA Garmin EMAP receiver messages, which are contained in the composition of one era.
$ GPRMC, 135412, A, 5522.8973, N, 0.0710.1401, E, 0.0.0.0,190507,9.3, E, A * 1F
$ GPRMB, A ,, A, A * 0B
$ GPGGA, 135412,5522.8973, N, 03710.1401, E, 1,04,5.4,205.2, M, 15.8, M, * 4A
$ GPGSA, A, 3,08,13,23,25,5.7,5.4,1.0 * 3C
$ GPGSV, 3,1,11,02,15,267,00,0,11,085,45,04,05,236,00,08,39,233.00 * 77
$ GPGSV, 3,2,21,10,32,308,00,13,63,109,43,16,17,11,00,23,31,111,38 * 77
$ GPGSV, 3,3,11,24,09,343,00,25,66,077,44,27,69,229.00 * 46
$ GPGll, 5522.8973, N, 03710.1401, E, 135412, A, A * 43
$ Gpbod, t, m, * 47
$ PGRME, 19.1, M, 15.2, M, 25.3, M * 15
$ PGRMZ, 673, F, 3 * 19
$ PGRMM, WGS 84 * 06
In addition to standard NMEA messages, the Garmin receivers implements its own set of messages, each of which in the header contains the "GRM" prefix, the "M" or "Z" identifier, which defines the data type, and one character for the title.
PGRME - Assessment of positioning errors
$ PGRME, 15.0, M, 45.0, M, 25.0, M * 1C
15.0, M - assessment of horizontal positioning error, in meters
45.0, M - assessment of the vertical error, in meters
25.0, M - equivalent spherical positioning error
PGRMZ - Height Measurements
$ PGRMZ, 93, F, 3 * 21
93, F - height value, pounds
3 - position measurement conditions (2 - height defined by the user,
3 - Height calculated by GPS)
PGRMM - Current Datum
$ PGRMM, NAD27 Canada * 2f
NAD27 Canada - the name of the current horizontal datum
Features SIRF.
GPS SIRF chips are used in various navigation GPS equipment, ranging from ordinary boards, ending with portable and automobile GPS navigator. But unlike navigators, they only support NMEA messages associated with GPS measurements, position and time calculation - GGA, GLL, GSA, GSV, RMC, VTG, ZDA.
"SIRF" also supports several "incoming" NMEA messages intended for configuration and configuration of various parameters. In addition, the "SIRF" is implemented its own binary protocol that allows you to change much more settings. These 5 "incoming" NMEA messages in accordance with the rules begin with the $ PSFR prefix. All messages contain a fixed data set and end with the "\\ N" symbol.
To configure the SIRF parameters, the SIRFTECH special program is used. Setting the NMEA parameters The message is carried out in a separate menu item.
$ Gpgga, 100643.000,5522.9036, n, 03710.1282, E, 1,07,1,6,209.9, m, 14.9, m, 0000 * 52
$ GPGSA, A, 3,31,01,23,20,11,30,14,2.1,1,6,1.4 * 35
$ GPGSV, 3,1,12,20,84,187,41,01,49,067,46,23,46,238,45,31,45,073,50 * 7B
$ Gpgsv, 3,2,12,11,25,194,34,13,16,240,04,15,319,30,17,14,273,21 * 7A
$ GPGSV, 3,3,12,30,10,026,33,14,05,063,22,05,04,009,25,25,03,195, * 7f
$ GPRMC, 100643.000, A, 5522.9036, N, 03710.1282, E, 0.16,199.11,200507, * 0D
As can be seen from the above example, the "factory" settings contain a smaller number of NMEA messages compared to the GARMIN settings. If necessary, this set can be expanded by setting the period in the missing NMEA messages.
$ GPGGA, 100833.000,552.9076, N, 03710.1270, E, 1,07,1.3,222.4, M, 14.9, M, 0000 * 53
$ GPGLL, 5522.9076, N, 03710.1270, E, 100833.000, A * 34
$ GPGSA, A, 3,31,01,23,20,11,30,17,2.1,1.3,6 * 31
$ GPGSV, 3,1,12,20,84,180,43,01,49,067,47,23,47,238,45,31,45,072,49 * 77
$ GPGSV, 3,2,12,11,24,193,26,13,16,240,26,04,15,319,24,17,13,273,31 * 78
$ GPGSV, 3,3,12,30,10,025,6,14,04,064,22,25,04,195,05,04,008,21 * 7c
$ GPRMC, 100833.000, A, 5522.9076, N, 03710.1270, E, 0.18,4.86,200507, * 00
$ GPVTG, 4.86, T, M, 0.18, N, 0.3, K * 60
$ GPZDA, 100834.000,20,05,2007, * 5A
PSFR100, PSFR102 - Configuration of Serial Ports
NMEA message Number 100 Used to install the port A, message 102 - Port V. Message 100 has an additional field that allows you to switch the interface to the binary SIRF protocol.
Accordingly, there is a command in the binary protocol that switches the port back to the NMEA format. Before switching to the binary protocol, it is necessary to understand whether the program will continue to restore the NMEA protocol.
$ PSRF100,0,9600,8,1,0 * 0C
$ PSRF102,9600,8,9,0 * 3C
PSRF100 - NMEA Title
0 - a parameter indicating what mode protocol (0-SIRF, 1-NMEA) has been changed
9600 - port speed (4800, 9600, 19200, 38400)
8 - Data bits (7, 8)
1 - Stop bits (0,1)
0 - paired (0 - no, 1 odd, 2-even)
PSFR101, PSFR104 - initialization of receiver parameters
NMEA messages under numbers 101 and 104 are designed to initialize the parameters intended for GPS reception. The definition of these parameters can speed up the capture time of the GPS satellites. Message 101 Sets current coordinates in XYZ format, message 104 - in BLH format (longitude, latitude).
$ PSRF101, -2686700, -4304200,3851624,95000,497260,921,12,3 * 22
$ Psrf104,37.3875111, -121.97232,0,95000,237759,922,12,3 * 3A
PSRF101 - NMEA Title
37.3875111 - Latitude in degrees
121.97232 - Longitude in degrees
0 - height, meters
95000 - clock shift
237759 - GPS time, seconds
922 - GPS WEEK Number
12 - Number of channels
3 - Data Initialization Type (1 - Hot Start, 2 - Warm Start, 3 - Data Initialization, 4 - Cold Start With Full Data Cleaning, 8 - Cold Start with Restoring Factory Settings)
PSFR103 - NMEA generation generation configuration
This NMEA message allows you to install or request a period of generating each "outgoing" NMEA message.
$ PSRF103,05,00,01,01 * 20
PSRF103 - NMEA Title
05 - message name
01 - Period, in seconds (0-255)
01 - Availability of Chexum (0- yes, 1 - no)
Experiment results
In terms of normal satellites, the Garmin Emap receiver issues the following set of NMEA messages:
$ GPRMC, 104644, A, 5522.8965, N, 0.0710.1389, E, 0.0.0.0.0,200507,9.3, E, A * 16
$ GPRMB, A ,, A, A * 0B
$ GPGGA, 104644.5522.8965, N, 03710.1389, E, 1,07,1.2,186.6, M, 15.8, M, * 44
$ Gpgsa, a, 3,01,04,13,16,20,23,31,2.1,1,1,7 * 35
$ GPGSV, 3,1,10,01,34,070,48,04,28,311,40,11,10,190,00,13,32,249,41 * 7e
$ GPGSV, 3,2,10,16,11,111,40,20,68,142,50,23,64,247,49,25,21,196.00 * 70
$ GPGSV, 3,3,10,30,05,012,00,31,36,055,52 * 7d
$ Gpgll, 5522.8965, N, 03710.1389, E, 104644, A, A * 40
$ Gpbod, t, m, * 47
$ PGRME, 6.0, M, 7.7, M, 9.8, M * 29
$ PGRMZ, 612, F, 3 * 1E
$ PGRMM, WGS 84 * 06
$ GPRTE, 1,1, C, * 37
From analysis of the messages, it is clear that at the current receiver 10 (GSV) satellites are monitored, of which 7 (GGA) are used in the position counting. Horizontal positioning error at the same time equals 6 meters (RME), and Solution indicator - 1 (GGA)
If you create the conditions under which the GPS signal will not be accepted, the GGA messages will contain "empty" fields, and the Solution type indicator will take value 0 (GGA)
$ GPGGA, 0,00, M, M, * 66
$ GPGSA, A, 1 ,, * 1E
In the "normal" mode of the RMB and BOD message contain empty fields. After the waypoint "Road" was chosen as the end point destination, these fields were "filled" data. As the analysis follows from the analysis, the distance to the point is 1.620 miles, the azimuth of the movement is 6.3 degrees (BOD). At the same time, the azimuth of BOD and RMB messages differs at 0.1 degrees.
$ GPRMB, A, 0.00, R, Road, 5524.501, N, 03710.445, E, 1.620,6.4, V, A * 59
$ Gpbod, 6.3, t, 357.0, m, road, * 74
After the "Home" route was selected to navigate the RTE message list, a list of all route dots appended. And in the RMV message - the identification numbers of the initial and final (next) point of the route.
$ GPRTE, 1,1, C, Home, Sloboda, Ierusalim, Institut * 01
$ GPRMB, A, 9.99, R, Slobod, Ierusal, 5555.237, N, 03649.976, E, 34.346,340.6, V, A * 1F
Conclusion
In most cases, the user does not need, and it is not interesting to know which data and in which fields are transmitted. Most navigation programs "disassemble" data NMEA messages and represent them in user-friendly form - graphics, schemes, tables, etc.
Of particular interest are NMEA messages for users who would like to conduct GPS data, calculate the estimates of the measurements obtained, or analyze the behavior of navigation receivers in various conditions. There are a number of programs with which you can solve these tasks.
But still, for deep analysis of GPS data, the NMEA format is not intended, since it does not contain the so-called "raw" measurements - pseudodality, phases, doppler. Each manufacturer of navigation equipment has its own "open" or "closed" protocol that displays this information.
NMEA is a simple and understandable format that allows not only to ensure the exchange of data between GPS receivers and navigation programs, but also gives users some idea of \u200b\u200bthe principles of satellite navigation equipment.
Attention!
An article from the site is used as the source material. GPS portal"
NMEA 0183. (from " National Marine Electronics Association") - Standard Defining the textual communication protocol of the maritime (as a rule, navigation) equipment (or equipment used in trains). It became especially popular in connection with the spread of GPS receivers using this standard.
General view of rows in NMEA 0183
- the symbol "$" or "!" (Hex 24 or Hex 21)
- 5-letter message identifier. The first two letters - the source identifier of the message, the following three letters - the message format identifier, according to the NMEA 0183 protocol of a specific version.
- list of data (letters, numbers and points) separated by commas. If any data is missing inside Rows, commas are still set (for example, ","). Some fields in the end Rows may be absent at all.
- symbol "*".
- eight-bit XOR -Summage of all characters (including "," and "^") in the line between "$" and "*" given to two ASCII symbols in the upper case for the 16-riche submission of bytes (0-9, A-F) .
(Hex 0D, Hex 0a).
Maximum message length is limited to 82 characters (NMEA 0183 REV 3.0)
The standard describes more than 250 NMEA sequence identifiers. The standard determines the rate of data exchange of 4800 bodes. (For speeds of 38400 baud and above there is an advanced standard NMEA-0183-HS).
Standard Allows you to add your own sequence identifiers, which is often used by manufacturers for transmission for more information About the operation of the device.
RMC string (private example)
$ GPRMC, HHMMSS.SSS, A, GGMM.MM, P, GGGMM.MM, J, V.V, B.B, DDMMYY, X.X, N, M * HH
Fields:
- "GP" - source identifier; In the example above, it is GPS, "GL" - GLONASS, "GA" - Galileo, "GN" - GLONASS + GPS, etc.
- RMC - "Recommended Minimum Sentence C"
- "HHMMSS.SSS" - the location time of the worldwide coordinated time UTC: "HH" - clock, "MM" - minutes, "ss.sss" - seconds. The length of the fractional part of seconds varies. The leading zeros are not lowered.
- "A" - Status: "A" - data is reliable, "V" is unreliable.
- "GGMM.mm" - latitude. 2 digits of degrees ("GG"), 2 digits of integer minutes, point and fractional part of minutes of variable length. The leading zeros are not lowered.
- "P" - "n" for northern or "s" for southern latitude.
- "Gggmm.mm" - longitude. 3 Digitles of degrees ("GGG"), 2 digits of integers, point and fractional part of the variable length. The leading zeros are not lowered.
- "J" - "E" for Eastern or "W" for Western longitude.
- "V.V" is a horizontal component of speed relative to the Earth in nodes. Floating point number. Whole and fractional parts of variable length.
- "B.B" is a way angle (direction of speed) in degrees. Floating point number. Whole and fractional parts of variable length. The value of 0 corresponds to the movement to the north, 90s - East, 180 - South, 270 - west.
- "DDMMYY" - date: day of the month, month, the last 2 digits of the year (leading zeros are mandatory).
- "X.X" - magnetic decline in degrees (often absent), calculated on some model. Floating point number. Whole and fractional parts of variable length.
- "N" - the direction of magnetic decline: to obtain a magnetic course, magnetic declination is necessary "E" - subtract, "W" - add to the true course.
- "M" is the mode indicator: "A" - autonomous, "D" - differential, "E" - approximation, "N" - unreliable data (often absent, this field is missing in old NMEA versions).
- "HH" - check sum.
- Byte is 0x0d. - Byte is 0x0a.
Examples of the RMC string
Example 1.
$ GPRMC, 125504.049, A, 5542.2389, N, 03741.6063, E, 0.06,25.82,200906, * 17
Fields:
- 12 hours 55 minutes 4,049 seconds UTC
- "A" - reliably
- latitude 55 ° 42,2389 ", Northern
- longitude 37 ° 41,6063 ", Eastern
- speed \u200b\u200b0.06 nodes
- Sea stations
- River stations
- Others
Marine radio equipment - equipment intended for the protection of human life at sea, ensuring the safety of navigation, the management of the work of the fleet and the transfer of public and private correspondence. For the efficient use of radio equipment on the courts, it is necessary to know its principles of construction, specifications and features of operation. Depending on the area of \u200b\u200bswimming in the sea radio equipment, various requirements are put forward.
A1 - In the zone of coastal umbl-radiotelephone stations using Tsive.
A2 - in the range of PV-radiotelephone stations using the Tsill, excluding the area A1.
A3 - in the area of \u200b\u200bthe satellites of Inmarsat, excluding areas A1 and A2.
A4 - outside the districts of A1, A2, A3.
Thus, the radio equipment on the vessel consists of three complexes: the equipment of the VHF range, the equipment of the PV / KV-band and the ship earth station (NWS) of the InMarsat system. Regardless of the diving areas, each vessel must be installed: VHF radio installation, RPL (radar beacon-respondent), Navtex receiver, ARB (emergency radio), portable emergency vapor radio stations.
Radio equipment on the vessel should meet the requirements of the GMDD, specified in the RMRS Rules (Russian Maritime Register of Shipping) and RDR (Russian River Register). Each vessel should be placed a spare power source, with which radio equipment could provide a connection with a distress in the event of a breakdown or damage to the main and emergency energy sources. When moving from one power source to another, the light and sound alarm should be triggered. Maintenance is provided to work and repair equipment, which performs the following procedures: delivery to installation site, storage (if necessary) and installation. All of these stages must be performed in accordance with the instructions in the technical documentation.
The quality of radio equipment is a totality of indicators that determine its compliance with the current requirements of science and technology. Indicators of the quality of the device include reliability, operational characteristics, cost-effectiveness, safety, design, etc. Many indicators have a numerical significance and, in essence, determine the effectiveness of the use of any equipment on the vessel.
On ships with displacement over 500 R.T. There must be at least three VHD portable stations and two radar respondents. On ships with displacement from 300 to 500 R.T. - Two stations and 1 RLO. It is also recommended to equip vessels for receiving facsimile.
In the catalog of the company's products you can get acquainted with various models And the brands of global manufacturers of radio equipment and make the necessary order.
- Gyroscopic compasses
- Magnetic compasses
- Cardplotters
- Lagi
- Meteertators
- GNSS GPS / GLONASS receivers
- Radar stations
- Repeitors
- SCDVP (BNWAS)
- RDR / U-RDR data recorders
- Automatic Identification System (AIS)
- External Sound Signals Receive Systems
- Sonora
- Satellite compass
- Echohotot
- Autodulus
- Electronic cartography
- Fleetbroadband
- INMARSAT LRIT, SSAS (ACDD, SSOO)
- Iridium (Iridium)
- Satellite television
- Terminals bgan.
- Terminals vsat.
Satellite communications at sea is currently an important means of message with the shore. Satellites of various operators create a large coverage of the earth's surface, which provides communication from any point of the globe.
On ships, applied classification communities, used as required to install satellite equipment, as well as additional. On small ships, boats, yachts, satellite equipment is used at the discretion of the owners and mainly to access the Internet.
Types of equipment:
Inmarsat Lrit, SSAS Terminals (OSD, SSOO) are marine satellite equipment, mandatory for installation on passenger, commercial and cargo ships with areas of navigation A2, A3, A4.
- Ship security alert system - allows you to send a hidden alarm in case of an attack on the ship. ACDD or LRIT is a system of identification of ships and tracking them at the far distance.
- FleetBroadband terminals - this equipment of the marine system satellite communicationsgiving broadband Internet access providing satellite telephone communication, Transfer SMS messages.
- VSAT - equipment providing high-speed data transmission through satellite Internetthat allows you to organize even video conferencing on board.
Also, for these purposes, BGAN terminals are used, differing from FBB equipment and VSAT compactness, mobility and communication speed.
From the high-specialized satellite marine equipment on ships: satellite service station, signal reception antenna and, for long-range sailing areas and phones running through satellite communications systems of operators such as Iridium, Inmarsat and Thuraya.
- Krenometers
- Navis automation systems
- Praxis automation systems
- MPS automation systems
- Fuel Consumption Control Systems
- Sensors
- Automation systems ABS
- Automation systems roll
1. Service, service and repair of ship electricity:
- Automation of systems remote control main engines;
- automation of ship power plants;
- repair and configuration of GEU systems;
- repair, commissioning and testing of automation and emergency warning alarm main engines (Wartsila, Man, Mak, SKL);
- repair, commissioning and testing of automation and emergency warning alarm auxiliary and emergency diesel generators (Volvo Penta, Scania, Deutz, Cat).
2. Service, service and repair of electrical equipment of general public systems:
- repair, adjustment of steering devices and automation of auto-rules;
- repair, commissioning, comprehensive check of fire alarm systems;
- automation of boiler equipment;
- automation of fuel preparation systems;
- automation of water treatment systems;
- Automation of wastewater treatment systems.
3. Service, service and repair of electrical equipment of deck mechanisms.
4. Development and coordination of project documentation for the modernization and refurbishment of vessel automation systems.
5. Capital, medium and current repair of electric motors and generators of any power. Repair and configuration of the generator excitation system, setting up the parallel operation of the generators.
- Headset and tubes
- Hydrostaty
- Spare parts for KVU
- Zip for gyrocompassas
- Zip for Typhonov
- Magnetron
- Converters and distributors
- Escaretable communication systems
- Fire safety systems
- Ship displays and PCs
- Ship Tiffons
- Elements of power (AKB)
- Power supplies
- Additional blocks
I had the need to test the application using the GNSS data using the NMEA protocol. It was due to the fact that he worked on the project of the aircraft navigation program, test in the air is expensive naturally, on Earth, ride the car with a GNSS receiver is not particularly convenient, so I wanted to sit at the table to have on the virtual parallel port NMEA protocol data from allegedly moving equipment. At first, I was looking for a different software thought, I will find something suitable, but most of the paid and control of data emulation is not entirely convenient, although almost all parameters of the NMEA standard are emulated. But I needed something simple emulating coordinates, the speed, in principle, no more and more convenient and logical control was required. So I had to write the application of this kind on C #.
Fly_nmea.
NMEA ("National Marine Electronics Association") - the full name "NMEA 0183" - the text of the marine communication protocol (as a rule, navigation) equipment among themselves.
Data is transmitted as proposals. The format of proposals is as follows:
$ Aaaaa [,<данные> ] * HH Where:
$ - the proposal start symbol (code 24h);
AAAAA - five-character address (name) of proposals;
[, <данные> ] - list of data fields separated by commas (2SH code);
* - sign of the checksum (2Ah code);
HH - checksum.
Example sentences:
GGA - GPS Definition Data
Time place and data related to observation.
$ GPGGA, HHMMSS.SSS, LLL.LL, A, YYYY.YY, A, X, XX, X.X, X.X, M, X.X, M, X.X, XXX * HH
I needed to emulate four lines:
- GLL - location coordinates
- GSV - Visible satellites
- RMC - Recommended Minimum GPS and Glonass Data Set
- GSA - the accuracy deterioration factor used to navigate satellites
- we set the initial coordinates in the WGS-84 system
- next, go to a flat projection, such as a mercator (for converting the coordinates I used a ready-made library on C #)
- knowing the flat coordinates X, Y, H we implement the physics of the aircraft movement by variable parameters through graphic interface, such as: roll, pitch, speed
- we convert flat coordinates in the coordinates B, L, H system WGS-84
- we form a NMEA standard message package from the required four lines.
- send them to a virtual parallel port
Fly_NMEA + Android Sensor
For more convenient testing, I still adjusted data reception with Android sensors (tilt angles). Android on UDP sends two rows of type:- "Angle: \\ T236.04152 \\ T-1.0 \\ T-3.0"
- "ACC: \\ T-0.46309182 \\ T-0.14982383 \\ T-10.56939"
- Pitch
Connect Fly_NMEA
To emulate COM ports, another Virtual Serial Ports Emulator will be useful, you will need to configure the connection of two virtual COM ports for example: COM1<-> COM6 and Fly_NMEA program will send data to the COM6, and on the COM1 program using the NMEA protocol will take them.Conclusion
In general, I spent more time to search for such software, and not finding that I would fully satisfied faster writing it myself. By the project on which I worked, I also managed to fully connect the emulator to programs that understand the NMEA protocol as: 2GIS and SAS Planet.
Flynmea and Android Sensor (Data Transmission Project with UDP Sensors)
You are probably busy with solving the problem of hacking the next mega-super-hyper Servak, but do you know what GPS is and how to contact him?! If not, then you here! In this article, I will tell you about how GPS receivers work, how to get information from them, as well as write yourself simple program To work with the GPS module.
GPS (Global Positioning System, Global Positioning System) was enacted in the USA in 1994. It consists of 24 satellites and terrestrial receiving complexes, which can be both your GPS navigator or GPS module (in the future navigator). To accurately determine the coordinates, your navigator must see at least 4 satellites. In the previous past, the accuracy of determining coordinates outside the United States (and more precisely for consumers not from the USA) was artificially reduced, but not so long ago, this restriction was removed and now you can determine your location even in a taiga with an accuracy of several meters.
On the fingers it works like this: your navigator receives information from each of the visible satellites, which are for him as beacon. Inside the navigator there is a microprocessor with a program sewn into it, which is based on the data obtained and calculates your location.
Currently, there is a huge amount of GPS navigators and GPS modules for PDAs and laptops. GPS navigator is a GPS receiver with a screen that displays information about your location, and the GPS module is a GPS receiver that connects to the computer and transmits all the navigation information of the program that works with it. All of them, in principle, differ only in the form factor and fundamental differences in the work do not have. But you are more interested in how much you still communicate with a computer and how to pull out information from it. Now I'll tell you everything and show.
What kind of form factor (COM, USB, Bluetooth, etc.) was not a GPS module, it will be logically connected to the computer through the COM port, i.e. When connected, a connection is created on a serial port. Navigation information In most cases is transmitted via the NMEA protocol. This is the most common transmission protocol for GPS modules. Although there are other protocols, but we will not consider them.
Well, now the time to find out how to make software to work with all this economy. I will say right away that I don't really want to explain how to poke into the buttons in the same
VB, the article is more familiarized. For those who in the tank I will explain like the process of creating a program in the following articles.
I will light only the most important moments and I think you will succeed. I will say right away that the program can be used in any programming languages, if only it was possible to work with the serial port and with rows.
The first where to start it from the opening of the COM port. Almost all receivers by default are settings: Speed \u200b\u200b9600 bits / s, 8 / N / 1. As soon as you open the port you immediately with an interval in a second will come navigation information about this type:
$ GPGGA, 143345.264, 0936.23, N, 06354.15, E, 0.06,0.0,230.6, m, 0.0, m, 0.0,0345 * 76
$ GPRMC, 143345.26, A, 0936.23, N, 06354.15, E, 0.0.0.0,230306,0.0, E, A * 45
$ GPGSA, A, 3,03, 04.05.07,11,12,0,0,0,0,0.0 * E2
$ GPGSV, 1,1,06,05,67,120,20 * 34
Now proceed to the analysis:
Data is transmitted as proposals. The format of proposals is as follows:
$ Aaaaa [,<данные> ] * HH
$ - the proposal start symbol (code 24h);
AAAAA is a five-grade address (name) of the sentence;
[, <данные> ] - list of data fields separated by commas (2SH code);
* - sign of the checksum (2Ah code);
HH - checksum;
Types of data fields.
| Type of field | Designation | Definition |
|
Special format fields |
||
| Status | A. | A field of one symbol. A \u003d yes, data reliable, warning signal not. V \u003d no, data is not reliable, there is warning signal. |
| Latitude | lLL.LL. | degrees-minutes shares minutes. 2 sign The number of signs of a minima. If first the sign of degrees or the minutes is missing, then It is replaced by zero in order to Great resolution. |
| Longitude | yyyyy.yy. | Field of constant / variable length: Degree minute and minutes of a minute. 3 sign degrees, 2 sign minutes and variable The number of signs of a minima. If first There is no signs or first sign, they are replaced by zero to Save a constant number of characters. Devimal point and subsequent signs Shares are additional and may not be used if not needed Great resolution. |
| Time | hhmmss.ss. | Field of constant / variable length: hours / minutes / seconds And the fraction of a second. 2 watches sign, 2 characters minutes, 2 characters seconds and variable number Signs of the share of seconds. As the first watches sign, minutes, seconds can be set zero to save constant number of signs. If not High accuracy is required, Devimal point and shares of seconds can To be omitted. |
| Certain fields | Some fields specially are intended to accommodate in advance certain permanent values, more often Total let's notice. Sign such fields is the presence of one or Multiple signs. |
|
Fields of digital values
Information fields
Notes:
1. Spaces can only be used in the fields of texts of the variable length.
2. Negative sign "-" (code 2DH) is the first sign of the field if negative values \u200b\u200bare given. When using a negative sign in the fields of fixed length, their length increases by one. With positive values, the sign is lowered.
GGA - GPS Definition Data
Time place and data related to observation.
$ GPGGA, HHMMSS.SSS, LLL.LL, A, YYYYY.YY, A, X, XX, X.X, X.X, M, X.X, M, X.X, XXXX * HH
1. HHMMSS.SSS - the time of navigation definitions;
2. LLLL.LL, A - latitude, N / S;
3. yyyyy.yy, A - longitude, E / W;
4. X - Observation quality indicator: 0 \u003d No data, 1 \u003d Observation obtained, 2 \u003d Observation in differential mode;
5. XX - the number of satellites used;
6. X.x - the magnitude of the horizontal geometric factor (HDOP);
7. X.x, m - antenna height above sea level (geoid), m;
8. X.x, m - excess of the geoid over the Ellipsoid WGS84, M;
9. X.x - obsolescence of differential amendments, that is, time in seconds from the moment the last differential correction is obtained, the zero field is used if the differential mode is turned off;
10. XXXX - Differential station identifier 0U1023.
Time, date, coordinates and course read by equipment.
$ GPRMC, HHMMSS.SS, A, LLL.LL, A, YYYYY.YY, A, X.X, X.X, XXXXXX, X.X, A, A * HH
The fields of this offer are:
1. HHMMSS.SS - time;
2. A - status (A / V);
3. LLLL.LL, A - latitude, N / S;
4. yyyyy.yy, a - longitude, E / W;
5. X.x - speed in nodes;
6. X.x - course in degrees;
7. XXXXXX - Date: DD / MM / YY (day / month / year);
8. X.x, a - magnetic decline in degrees, E / W;
9. A - Mode Indicator: A \u003d Autonomous Observation, D \u003d Differential Mode, N \u003d Data is unreliable.
GSA - the accuracy deterioration factor used to navigate satellites
$ Gpgsa, a, x, xx, ..., xx, x.x, x.x, x.x * hh
The fields of this offer are:
1. A - Mode of control of the number of determined coordinates: M \u003d manual, mode is indicated, A \u003d automatic switching;
2. X - Operating mode: 1 \u003d Observation is not possible, 2 \u003d The two coordinates are determined, 3 \u003d the three coordinates are determined;
3. XX ... XX - Satellite numbers used to solve the navigation problem, the number of fields is equal to the number of receiver channels, for GPS, 1-132 are used for WAAS 33E64, for GLONASS 65ё96;
4. X.x - general geometric degradation factor (PDOP);
5. X.x is a horizontal geometric factor of deterioration of accuracy (HDOP);
X.x is a vertical geometric deterioration factor (VDOP).
GSV - Visible satellites
The number of satellites in the radiovidance zone, satellite number, elevation angle, azimuth and signal-to-noise ratio. One sentence may contain information about 1 to 4 satellites, additional data on satellites are transmitted in the following sentences. The offer number is indicated in the first two data fields. For satellite Systems The following rooms are reserved: for GPS 1-32, for Waas 33-64, for GLONASS 65-96.
$ GPGSV, X, X, XX, XX, XX, XXX, XX, ..., XX, XX, XXX, XX * HH
The fields of this offer are:
1. X - the total number of messages;
2. X - message number;
3. XX - the total number of satellites in the radiochability zone;
4. XX - satellite number;
5. XX - the angle of elevation of the satellite, degrees 00-90;
6. XXX - Azimuth True, degrees 000-360;
7. XX - Signal / noise ratio 00-99 dB if the satellite is not accompanied.
Note: Fields 4, 5, 7 are repeated for 2, 3 and 4 satellites.
Well, now, having a NMEA protocol description and a direct_rushki driver .Sys you can proceed to the line of packets and creating mega programmalls)))).
