EndRun Sonoma N12, User Manual

Page: 116 / 174

S o n o m a U s e r M a n u a l 100
C H A P T E R T E N
101 S o n o m a U s e r M a n u a l
O P T I O N S
NMEA Format
The National Marine Electronics Association (NMEA) has developed a specification that defines the
interface between various pieces of marine electronic equipment. This standard defines “sentences”
that contain GPS position, navigation, time, and other information. Sentences that have been imple-
mented in the Sonoma conform to NMEA-0183 Specification Version 3.01 and are GGA, GLL, GSA,
RMC, VTG and ZDA. Your Sonoma can output one, two, or three of these sentences per second.
Not all information defined in the NMEA sentences is available from the GPS Receiver resident in
the Sonoma. Following are the definitions for the NMEA sentences as implemented in this product:
NOTE: Up to 3 sentences may be transmitted per second. The first character (“$”) of the first
sentence is the “on-time” character. Once the unit is locked to GPS, the “on-time” character starts
transmitting within the first 20 microseconds of each second..
GGA (GPS Fix Data)
The GGA sentence contains the time, position, and fix related data. (EndRun does not calculate mean
sea level.) Examples are below:
$GPGGA,,,,,,,0,00,,,M,,,*2B<CR><LF>
$GPGGA,173423.00,3827.030,N,12244.020,W,1,08,1.2,14.5,M,,,,0000*72<CR><LF>
Msg ID $GPGGA
Field 1 173423.00 UTC time of fix (hhmmss.ss)
Field 2 3827.030 Latitude in ddmm.mmm
Field 3 N Direction of latitude (N=north, S=south)
Field 4 12244.020 Longitude in dddmm.mmm
Field 5 W Direction of longitude (W=west, E=east)
Field 6 1 Fix quality indicator (0=fix not valid, 1=GPS fix)
Field 7 08 Number of SVs in use, 00-08
Field 8 1.2 HDOP (horizontal dilution of precision)
Field 9 14.5 Altitude above WGS84 ellipsoid (we do not calculate mean sea level)
Field 10 M “M” indicates altitude is in meters
Field 11 empty field Height of geoid (mean sea level)
Field 12 empty field Units of geoidal separation
Field 13 empty field Time in seconds since last DGPS update
Field 14 empty field DGPS station ID number
Checksum *72
Msg End <CR><LF>
GLL (Position Data)
The GLL sentence identifies the position fix, time of position fix, and status. Examples are below:
$GPGLL,,,,,,,V,N*64<CR><LF>
$GPGLL,3827.030,N,12244.020,W,173423.00,A,A*34<CR><LF>
Msg ID $GPGLL
Field 1 3827.030 Latitude in ddmm.mmm
Field 2 N Direction of latitude (N=north, S=south)