$GPGST

GPS Pseudorange Noise Statistics

Example: $GPGST,024603.00,3.2,6.6,4.7,47.3,5.8,5.6,22.0*58

$GPGSV

GPS Satellites in view

eg. $GPGSV,3,1,11,03,03,111,00,04,15,270,00,06,01,010,00,13,06,292,00*74
    $GPGSV,3,2,11,14,25,170,00,16,57,208,39,18,67,296,40,19,40,246,00*74
    $GPGSV,3,3,11,22,42,067,42,24,14,311,43,27,05,244,00,,,,*4D


    $GPGSV,1,1,13,02,02,213,,03,-3,000,,11,00,121,,14,13,172,05*62


1    = Total number of messages of this type in this cycle
2    = Message number
3    = Total number of SVs in view
4    = SV PRN number
5    = Elevation in degrees, 90 maximum
6    = Azimuth, degrees from true north, 000 to 359
7    = SNR, 00-99 dB (null when not tracking)
8-11 = Information about second SV, same as field 4-7
12-15= Information about third SV, same as field 4-7
16-19= Information about fourth SV, same as field 4-7

$GPHDT

Heading, True.

Actual vessel heading in degrees Ture produced by any device or system producing true heading.

$--HDT,x.x,T
x.x = Heading, degrees True

$GPMSK

Control for a Beacon Receiver

  $GPMSK,318.0,A,100,M,2*45

where:
       318.0      Frequency to use
       A          Frequency mode, A=auto, M=manual
       100        Beacon bit rate
       M          Bitrate, A=auto, M=manual
       2          frequency for MSS message status (null for no status)
       *45        checksum

$GPMSS

Beacon Receiver Status

Example 1: $GPMSS,55,27,318.0,100,*66

where:
       55         signal strength in dB
       27         signal to noise ratio in dB
       318.0      Beacon Frequency in KHz
       100        Beacon bitrate in bps
       *66        checksum

Example 2: $GPMSS,0.0,0.0,0.0,25,2*6D

$GPR00

List of waypoint IDs in currently active route

eg1. $GPR00,EGLL,EGLM,EGTB,EGUB,EGTK,MBOT,EGTB,,,,,,,*58
eg2. $GPR00,MINST,CHATN,CHAT1,CHATW,CHATM,CHATE,003,004,005,006,007,,,*05


List of waypoints. This alternates with $GPWPL cycle
which itself cycles waypoints.

$GPRMA

Recommended minimum specific Loran-C data

eg. $GPRMA,A,lll,N,lll,W,x,y,ss.s,ccc,vv.v,W*hh
A    = Data status 
lll  = Latitude
N    = N/S
lll  = longitude
S    = W/E
x    = not used
y    = not used
ss.s = Speed over ground in knots
ccc  = Course over ground
vv.v = Variation
W    = Direction of variation E/W
hh   = Checksum 

$GPRMB

Recommended minimum navigation information (sent by nav. receiver when a destination waypoint is active)

eg1. $GPRMB,A,0.66,L,003,004,4917.24,N,12309.57,W,001.3,052.5,000.5,V*0B


           A            Data status A = OK, V = warning
           0.66,L       Cross-track error (nautical miles, 9.9 max.),
                                steer Left to correct (or R = right)
           003          Origin waypoint ID
           004          Destination waypoint ID
           4917.24,N    Destination waypoint latitude 49 deg. 17.24 min. N
           12309.57,W   Destination waypoint longitude 123 deg. 09.57 min. W
           001.3        Range to destination, nautical miles
           052.5        True bearing to destination
           000.5        Velocity towards destination, knots
           V            Arrival alarm  A = arrived, V = not arrived
           *0B          mandatory checksum


eg2. $GPRMB,A,4.08,L,EGLL,EGLM,5130.02,N,00046.34,W,004.6,213.9,122.9,A*3D
            1   2  3   4    5    6     7   8      9   10    11    12   13

  
      1    A         validity
      2    4.08      off track
      3    L         Steer Left (L/R)
      4    EGLL      last waypoint
      5    EGLM      next waypoint
      6    5130.02   Latitude of Next waypoint
      7    N         North/South
      8    00046.34  Longitude of next waypoint
      9    W         East/West
      10   004.6     Range
      11   213.9     bearing to waypt.
      12   122.9     closing velocity
      13   A         validity
      14   *3D       checksum


eg3. $GPRMB,A,x.x,a,c--c,d--d,llll.ll,e,yyyyy.yy,f,g.g,h.h,i.i,j*kk
1    = Data Status (V=navigation receiver warning)
2    = Crosstrack error in nautical miles
3    = Direction to steer (L or R) to correct error
4    = Origin waypoint ID#
5    = Destination waypoint ID#
6    = Destination waypoint latitude
7    = N or S
8    = Destination waypoint longitude
9    = E or W
10   = Range to destination in nautical miles
11   = Bearing to destination, degrees True
12   = Destination closing velocity in knots
13   = Arrival status; (A=entered or perpendicular passed)
14   = Checksum

$GPRMC

Recommended minimum specific GPS/Transit data

eg1. $GPRMC,081836,A,3751.65,S,14507.36,E,000.0,360.0,130998,011.3,E*62
eg2. $GPRMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68


           225446       Time of fix 22:54:46 UTC
           A            Navigation receiver warning A = Valid position, V = Warning
           4916.45,N    Latitude 49 deg. 16.45 min. North
           12311.12,W   Longitude 123 deg. 11.12 min. West
           000.5        Speed over ground, Knots
           054.7        Course Made Good, degrees true
           191194       UTC Date of fix, 19 November 1994
           020.3,E      Magnetic variation, 20.3 deg. East
           *68          mandatory checksum


eg3. $GPRMC,220516,A,5133.82,N,00042.24,W,173.8,231.8,130694,004.2,W*70
              1    2    3    4    5     6    7    8      9     10  11 12


      1   220516     Time Stamp
      2   A          validity - A-ok, V-invalid
      3   5133.82    current Latitude
      4   N          North/South
      5   00042.24   current Longitude
      6   W          East/West
      7   173.8      Speed in knots
      8   231.8      True course
      9   130694     Date Stamp
      10  004.2      Variation
      11  W          East/West
      12  *70        checksum


eg4. for NMEA 0183 version 3.00 active the Mode indicator field is added
     $GPRMC,hhmmss.ss,A,llll.ll,a,yyyyy.yy,a,x.x,x.x,ddmmyy,x.x,a,m*hh
Field #
1    = UTC time of fix
2    = Data status (A=Valid position, V=navigation receiver warning)
3    = Latitude of fix
4    = N or S of longitude
5    = Longitude of fix
6    = E or W of longitude
7    = Speed over ground in knots
8    = Track made good in degrees True
9    = UTC date of fix
10   = Magnetic variation degrees (Easterly var. subtracts from true course)
11   = E or W of magnetic variation
12   = Mode indicator, (A=Autonomous, D=Differential, E=Estimated, N=Data not valid)
13   = Checksum

$GPRTE

Routes

eg. $GPRTE,2,1,c,0,PBRCPK,PBRTO,PTELGR,PPLAND,PYAMBU,PPFAIR,PWARRN,PMORTL,PLISMR*73
    $GPRTE,2,2,c,0,PCRESY,GRYRIE,GCORIO,GWERR,GWESTG,7FED*34
           1 2 3 4 5 ..

1. Number of sentences in sequence
2. Sentence number
3. 'c' = Current active route, 'w' = waypoint list starts with destination waypoint
4. Name or number of the active route
5. onwards, Names of waypoints in Route

$GPTRF

Transit Fix Data

Time, date, position, and information related to a TRANSIT Fix.

$--TRF,hhmmss.ss,xxxxxx,llll.ll,a,yyyyy.yy,a,x.x,x.x,x.x,x.x,xxx
hhmmss.ss = UTC of position fix
xxxxxx = Date: dd/mm/yy
llll.ll,a = Latitude of position fix, N/S
yyyyy.yy,a = Longitude of position fix, E/W
x.x = Elevation angle
x.x = Number of iterations
x.x = Number of Doppler intervals
x.x = Update distance, nautical miles
x.x = Satellite ID