GPS Messages

What information is send with each NMEA/PUBX message?

Message Data Types
PUBX00 S-TLAHSNPV
RMC SDTL-HS---
GGA S-TLA--NP-
GLL S-TL------
GSA S------NP-
VTG S----HS---

Data Types
S: Status
D: Date
T: Time L: Lat/lon
A: Altitude
S: Speed
H: Heading
N: Number of sats
P: DOP
V: Vertical velocity

PUBX00 u-blox Proprietary Message

$PUBX,00,081350.00,4717.113210,N,00833.915187,E,546.589,G3,2.1,2.0,0.007,77.52,0.007,,0.92,1.19,0.77,9,0,0*5F

Field No. Example Format Description
0 $PUBX string $PUBX Message ID, UBX protocol header, proprietary sentence
1 00 numeric Proprietary message identifier: 00
2 081350.00 hhmmss.sss UTC Time, Current time
3 4717.113210 ddmm.mmmm Latitude, Degrees + minutes
4 N character N/S N/S Indicator, N=north or S=south
5 00833.915187 Longitude - Longitude, Degrees + minutes
6 E character E/W E/W indicator, E=east or W=west
7 546.589 numeric Altitude in meters above user datum ellipsoid
8 G3 string Navigation Status, see table below
9 2.1 numeric Horizontal accuracy estimate in meters
10 2.0 numeric Vertical accuracy estimate in meters
11 0.007 numeric Speed over ground in km/h
12 77.52 numeric Course over ground in degrees
13 0.007 numeric Vertical downward velocity
14 - numeric Age of most recent DGPS corrections in seconds, empty = none available
15 0.92 numeric HDOP Horizontal Dilution of Precision
16 1.19 numeric VDOP Vertical Dilution of Precision
17 0.77 numeric TDOP Time Dilution of Precision
18 9 numeric Number of GPS satellites
19 0 numeric Number of GLONASS satellites
20 0 numeric DR used
21 *5F hexadecimal Checksum
22 - character Carriage Return and Line Feed

Navigation Status
NF No Fix
DR Dead reckoning only solution
G2 Stand alone 2D solution
G3 Stand alone 3D solution
D2 Differential 2D solution
D3 Differential 3D solution
RK Combined GPS + dead reckoning solution
TT Time only solution

Send: $PUBX,00*33<CR><LF> to poll PUBX00 message

GGA Message

$GPGGA,092725.00,4717.11399,N,00833.91590,E,1,8,1.01,499.6,M,48.0,M,,0*5B

Field No. Example Format Description
0 $GPGGA string $GPGGA Message ID, GGA protocol header
1 092725.00 hhmmss.sss UTC Time, Current time
2 4717.11399 ddmm.mmmm Latitude, Degrees + minutes
3 N character N/S N/S Indicator, N=north or S=south
4 00833.91590 dddmm.mmmm Longitude - Longitude, Degrees + minutes
5 E character E/W E/W indicator, E=east or W=west
6 1 digit Position Fix Status Indicator, See Table below
7 8 numeric Satellites Used, Range 0 to 12
8 1.01 numeric HDOP HDOP, Horizontal Dilution of Precision
9 499.6 numeric MSL Altitude in m
10 M character M MSL Altitude Unit, Meters (fixed field)
11 48.0 numeric Geoid Separation in m
12 M character M Geoid Separation Unit, Meters (fixed field)
13 - numeric Age of Differential Corrections in seconds, Blank (Null) fields when DGPS is not used
14 0 numeric Diff. Reference Station ID
15 *5B hexadecimal Checksum
16 - character Carriage Return and Line Feed

Fix Status
0 No Fix / Invalid
1 Standard GPS (2D/3D)
2 Differential GPS
6 Estimated (DR) Fix

RMC Message

$GPRMC,083559.00,A,4717.11437,N,00833.91522,E,0.004,77.52,091202,,,A*57

Field No. Example Format Description
0 $GPGGA string $GPRMC Message ID, RMC protocol header
1 083559.00 hhmmss.sss UTC Time, Current time
2 A character Status - Status, V = Navigation receiver warning, A = Data valid
3 4717.11437 ddmm.mmmm Latitude, Degrees + minutes
4 N character N/S N/S Indicator, N=north or S=south
5 00833.91522 dddmm.mmmm Longitude - Longitude, Degrees + minutes, see Format description
6 E character E/W E/W indicator, E=east or W=west
7 0.004 numeric Speed over ground in knots
8 77.52 numeric Course over ground in degrees
9 091202 ddmmyy date Date in day, month, year format
10 - numeric Magnetic variation value, not being output by receiver
11 - character Magnetic variation E/W indicator, not being outputby receiver
12 - character Mode Indicator, see Position Fix Flags description
13 *57 hexadecimal Checksum
14 - character Carriage Return and Line Feed