Nmea info

nmea

=== GGA - Global Positioning System Fix Data ===

Time, Position and fix related data for a GPS receiver.

------------------------------------------------------------------------------
                                                      11
        1         2       3 4        5 6 7  8   9  10 |  12 13  14   15
        |         |       | |        | | |  |   |   | |   | |   |    |
 $--GGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh<CR><LF>
------------------------------------------------------------------------------

Field Number: 

1. Universal Time Coordinated (UTC)
2. Latitude
3. N or S (North or South)
4. Longitude
5. E or W (East or West)
6. GPS Quality Indicator,
     - 0 - fix not available,
     - 1 - GPS fix,
     - 2 - Differential GPS fix
           (values above 2 are 2.3 features)
     - 3 = PPS fix
     - 4 = Real Time Kinematic
     - 5 = Float RTK
     - 6 = estimated (dead reckoning)
     - 7 = Manual input mode
     - 8 = Simulation mode
7. Number of satellites in view, 00 - 12
8. Horizontal Dilution of precision (meters)
9. Antenna Altitude above/below mean-sea-level (geoid) (in meters)
10. Units of antenna altitude, meters
11. Geoidal separation, the difference between the WGS-84 earth
     ellipsoid and mean-sea-level (geoid), "-" means mean-sea-level
     below ellipsoid
12. Units of geoidal separation, meters
13. Age of differential GPS data, time in seconds since last SC104
     type 1 or 9 update, null field when DGPS is not used
14. Differential reference station ID, 0000-1023
15. Checksum

=== GSA - GPS DOP and active satellites ===

------------------------------------------------------------------------------
	1 2 3                        14 15  16  17  18
	| | |                         |  |   |   |   |
 $--GSA,a,a,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x.x,x.x,x.x*hh<CR><LF>
------------------------------------------------------------------------------

Field Number: 

1. Selection mode: M=Manual, forced to operate in 2D or 3D, A=Automatic, 3D/2D
2. Mode (1 = no fix, 2 = 2D fix, 3 = 3D fix)
3. ID of 1st satellite used for fix
4. ID of 2nd satellite used for fix
5. ID of 3rd satellite used for fix
6. ID of 4th satellite used for fix
7. ID of 5th satellite used for fix
8. ID of 6th satellite used for fix
9. ID of 7th satellite used for fix
10. ID of 8th satellite used for fix
11. ID of 9th satellite used for fix
12. ID of 10th satellite used for fix
13. ID of 11th satellite used for fix
14. ID of 12th satellite used for fix
15. PDOP
16. HDOP
17. VDOP
18. Checksum

=== GSV - Satellites in view ===

These sentences describe the sky position of a UPS satellite in view.
Typically they're shipped in a group of 2 or 3.

------------------------------------------------------------------------------
	1 2 3 4 5 6 7     n
	| | | | | | |     |
 $--GSV,x,x,x,x,x,x,x,...*hh<CR><LF>
------------------------------------------------------------------------------

Field Number: 

1. total number of GSV messages to be transmitted in this group
2. 1-origin number of this GSV message  within current group
3. total number of satellites in view (leading zeros sent)
4. satellite PRN number (leading zeros sent)
5. elevation in degrees (00-90) (leading zeros sent)
6. azimuth in degrees to true north (000-359) (leading zeros sent)
7. SNR in dB (00-99) (leading zeros sent)
   more satellite info quadruples like 4-7
   n) checksum

Example:
    $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

Some GPS receivers may emit more than 12 quadruples (more than three
GPGSV sentences), even though NMEA-0813 doesn't allow this.  (The
extras might be WAAS satellites, for example.) Receivers may also
report quads for satellites they aren't tracking, in which case the
SNR field will be null; we don't know whether this is formally allowed
or not.

=== RMC - Recommended Minimum Navigation Information ===

------------------------------------------------------------------------------
                                                          12
        1         2 3       4 5        6  7   8   9    10 11|  13
        |         | |       | |        |  |   |   |    |  | |   |
 $--RMC,hhmmss.ss,A,llll.ll,a,yyyyy.yy,a,x.x,x.x,xxxx,x.x,a,m,*hh<CR><LF>
------------------------------------------------------------------------------

Field Number:

1. UTC Time
2. Status, V=Navigation receiver warning A=Valid
3. Latitude
4. N or S
5. Longitude
6. E or W
7. Speed over ground, knots
8. Track made good, degrees true
9. Date, ddmmyy
10. Magnetic Variation, degrees
11. E or W
12. FAA mode indicator (NMEA 2.3 and later)
13. Checksum

A status of V means the GPS has a valid fix that is below an internal
quality threshold, e.g. because the dilution of precision is too high 
or an elevation mask test failed.

=== VTG - Track made good and Ground speed ===

------------------------------------------------------------------------------
         1  2  3  4  5	6  7  8 9   10
         |  |  |  |  |	|  |  | |   |
 $--VTG,x.x,T,x.x,M,x.x,N,x.x,K,m,*hh<CR><LF>
------------------------------------------------------------------------------

Field Number: 

1. Track Degrees
2. T = True
3. Track Degrees
4. M = Magnetic
5. Speed Knots
6. N = Knots
7. Speed Kilometers Per Hour
8. K = Kilometers Per Hour
9. FAA mode indicator (NMEA 2.3 and later)
10. Checksum