Useful articles
Decoding of NMEA signals (Part 1)
This section describes the functionality associated with the reception of data from navigation sensors, supporting the standard IEC 61162-1 or NMEA 0183.
Summary table
Summary table illustrates the principles of interaction with each navigation sensor.
| Sensor |
The type of data transmitted by the sensor |
Posts supporting the transmitted data |
Channel in the System Configuration Utility / Service / Sensors / Accuracy of the connected sensor |
|---|---|---|---|
|
GPS (GLONASS, DECCA, LORAN)
|
Position |
GGA
GLL
RMC
SNU
|
Pos. system 1 (Pos. system 2) |
|
COG & SOG |
RMC VTG |
Pos. system 1 (Pos. system 2) |
|
|
Satellite information |
GGA |
Pos. system 1 (Pos. system 2) |
|
|
Datum |
DTM |
Pos. system 1 (Pos. system 2) |
|
|
LORAN-C data status |
SNU |
Pos. system 1 (Pos. system 2) |
|
|
UTC time |
ZDA
ZLZ
ZZU
GGA
GLL
|
Time |
|
|
UTC date |
ZDA |
Time |
|
|
ARPA
|
Targets |
TTM |
ARPA_A (ARPA_B) |
|
VRM's, EBL's, Cursor |
RSD |
ARPA_A (ARPA_B) |
|
|
Heading |
OSD
VHW
|
Compass |
|
|
Speed through the water |
OSD
VHW
|
Log |
|
|
Sounder |
Depth under the sounder vibrator |
DBT
DPT
DBK
DBS
|
Sounder |
|
Compass |
Heading |
HDT
HDM
OSD
VHW
|
Compass |
|
Speed log (dopler log)
|
Dpeed through the water |
OSD
VHW
VBW
|
Log |
|
SOG |
VBW |
Log |
|
|
Digital anemometer |
Wind direction speed |
VWR
MWV
VWT
|
Wind |
|
Digital thermometer |
Water temperature |
MTW |
Temperature |
|
Yeoman digitizer |
WP position |
WPL |
Yeoman |
Format Data
This section provides a description of message formats, standards IEC 61162-1 and / or NMEA 0183, received and processed by the various navigational instruments.
Message format consists of the following parts:
$ - AAA, xx, a, c --- c, ... * hh <CR> <LF>.
|
N |
Field |
Description |
|---|---|---|
|
1 |
$ |
Start of sentence |
|
2 |
- |
Talker id |
|
3 |
AAA |
Mnemonic code of identifying the data type |
|
4 |
, |
Data field delimiter |
|
5 |
xx, a, c --- c ... |
Data |
|
6 |
* Hh |
Checksum field |
|
7 |
<cr> <lf> |
End of sentence |
DBK (Depth Below Keel) - depth of water under the keel
Standard NMEA 0183 v.2.1, 1995 (not recommended for new designs).
$ - DBK, x.x1, f2, x.x3, M4, x.x5, F6 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|
1 |
xx |
Depth |
The depth |
|
|
2 |
f |
Unit |
'F' - ft |
|
|
3 |
xx |
Depth |
The depth |
|
|
4 |
M |
Unit |
'M' - Meters |
|
|
5 |
xx |
Depth |
The depth |
|
|
6 |
F |
Unit |
'F' - Fathoms |
|
DBS (Depth Below Surface) - water depth relative to the water surface
Standard NMEA 0183 v.2.1, 1995 (not recommended for new designs).
$ - DBS, x.x1, f2, x.x3, M4, x.x5, F6 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|
1 |
xx |
Depth |
The depth |
|
|
2 |
f |
Unit |
'F' - ft |
|
|
3 |
xx |
Depth |
The depth |
|
|
4 |
M |
Unit |
'M' - Meters |
|
|
5 |
xx |
Depth |
The depth |
|
|
6 |
F |
Unit |
'F' - Fathoms |
|
DBT (Depth Below Transducer) - depth, measured from the vibrator sonar
Standard IEC 61162-1, 2000.
$ - DBT, x.x1, f2, x.x3, M4, x.x5, F6 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|
1 |
xx |
Depth |
The depth |
|
|
2 |
f |
Unit |
'F' - ft |
|
|
3 |
xx |
Depth |
The depth |
|
|
4 |
M |
Unit |
'M' - Meters |
|
|
5 |
xx |
Depth |
The depth |
|
|
6 |
F |
Unit |
'F' - Fathoms |
|
DPT (Depth) - depth
Standard iec 61162-1, 2000 IMO Resolution a.224 (vii).
Contains: the depth measured from the vibrator sonar and correction value for the location of the vibrator. positive correction means the distance from the vibrator to the water surface, the negative - distance from the vibrator to the keel.
$ - DPT, x.x1, x.x2, x.x3 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|---|---|---|---|---|
|
1 |
xx |
The depth (in meters) |
|
|
|
2 |
xx |
Correction (in meters) |
|
not processed |
|
3 |
xx |
Maximum range scale in use |
|
not processed |
DTM (Datum reference) - geodetic data on the basis of
Standard IEC 61162-1, 2000.
Contains information on the reference ellipsoid into which the received coordinates.
$ - DTM, ccc1, a2, x.x3, a4, x.x5, a6, x.x7, ccc8 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|---|---|---|---|---|
|
1 |
ccc |
Local datum |
'W72' - WGS 72
'W84' - WGS 84
'IHO' - reference ellipsoid terminology IHO
'999' - reference ellipsoid defined by the user
'S85' - SGS85
'P90' - PE90
|
Processed only 'W84' |
|
2 |
a |
Local datum subdivision code |
|
not processed |
|
3 |
xx |
Lat offset, min |
|
not processed |
|
4 |
a |
Hemisphere |
'N' - North;
'S'-South
|
not processed |
|
5 |
xx |
Lon offset, min |
|
not processed |
|
6 |
a |
Hemisphere |
'E' - East;
'W' - West
|
not processed |
|
7 |
xx |
Altitude offset, m |
|
not processed |
|
8 |
ccc |
Reference datum |
'W84' - WGS84
'W72' - WGS72
'S85' - SGS85
'P90' - PE90
|
not processed |
GGA (Global Positioning System Fix Data) - coordinate data for gps
Standard IEC 61162-1, 2000.
Contains: time, location and related data from the receiver-GPS.
$ - GGA, hhmmss.ss1, llll.ll2, a3, yyyyy.yy4, a5, x6, xx7, x.x8, x.x9, M10, x.x11, M12, x.x13, xxxx14 * hh <CR > <LF>.
|
N |
Field |
Title |
Value |
Note |
|---|---|---|---|---|
|
1 |
hhmmss.ss |
UTC time of observation |
Hours, minutes, seconds |
not processed in 3000 ns ecdis |
|
2 |
llll.ll |
Latitude waypoint |
Degrees, minutes and tenths of minutes |
|
|
3 |
a |
Hemisphere |
'N' - the north; |
|
|
4 |
yyyyy.yy |
Longitude Waypoint |
Degrees, minutes and tenths of minutes |
|
|
5 |
a |
Hemisphere |
'E' - the east; |
|
|
6 |
x |
GPS quality indicator observation |
'0' - observation is impossible or ineffective;
'1' - valid observation, GPS type SPS;
'2' - observation is valid diff. GPS SPS type
'3' - valid observation, GPS PPS type
'4' - valid observation, RTK
|
'4' is not processed |
|
7 |
xx |
Number of satellites used |
0 to 12 |
|
|
8 |
xx |
Horizontal Dilution of Precision |
|
|
|
9 |
xx |
Antenna height above sea level |
|
not processed |
|
10 |
m |
Units |
'M' - Meters |
not processed |
|
11 |
xx |
Geoid separation |
The vertical difference between the ellipsoid 'WGS-84' and sea level (geoid), |
not processed |
|
12 |
m |
Units |
'M' - Meters |
not processed |
|
13 |
xx |
Age data diff. gps (seconds) |
|
|
|
14 |
xxxx |
Station code diff.gps |
from 0000 to 1023 |
|
GLL (Geographic Position - Latitude / Longitude) - geographic coordinates
Standard IEC 61162-1, 2000.
Contains: the coordinates of the MS, the time of observation and data status.
$ - GLL, llll.ll1, a2, yyyyy.yy3, a4, hhmmss.ss5, A6, a7 * hh <CR> <LF>.
|
N |
Field |
Title |
Value |
Note |
|---|---|---|---|---|
|
1 |
llll.ll |
Latitude waypoint |
Degrees, minutes and tenths of minutes |
|
|
2 |
a |
Hemisphere |
'N' - the north; |
|
|
3 |
yyyyy.yy |
Longitude Waypoint |
Degrees, minutes and tenths of minutes |
|
|
4 |
a |
Hemisphere |
'E' - the east; |
|
|
5 |
hhmmss.ss |
UTC time of observation |
Hours, minutes, seconds |
not processed in 3000 ns ecdis |
|
6 |
a |
Status data from the receiver- |
'A' - reliable data; |