Import of GPS-coordinates in format NMEA 0183
NMEA 0183 is a format of messages transfer for information interchange between navigation GPS-receivers and consumers of the navigation information.
Program for Import of GPS-coordinates is started from the menu: File/Import from /GPS/NMEA coordinates or File / Update / Coordinates GPS/NMEA.
In a mode of import the map can be created anew. In update mode the objects will be only added onto the chosen map.
The input data is the text file containing records in a format of NMEA 0183 report. The program processes the following messages of protocol NMEA 0183:
- $GPGGA (GPS), $GLGGA (ГЛОНАСС), $GNGGA (GPS+ГЛОНАСС);
- $GPGLL (GPS), $GLGLL (ГЛОНАСС), $GNGLL (GPS+ГЛОНАСС);
- $GPRMC (GPS), $GLRMC (ГЛОНАСС), $GNRMC (GPS+ГЛОНАСС);
- $GPGNS (GPS), $GLGNS (ГЛОНАСС), $GNGNS (GPS+ГЛОНАСС);
- $GPWPL (GPS), $GLWPL (ГЛОНАСС), $GNWPL (GPS+ГЛОНАСС).
When recording a track, a linear object with a four-dimensional metric (latitude, longitude, height, speed) is formed on the map. The «Speed» field is recorded as a floating point number in km/h. The value is selected from the velocity field and converted from knots to km/h (multiplied by 1.852).
The kind of created objects and a way of creation (a point or a line) are chosen in dialog.
Successively going records with identical coordinates are skipped. It is assumed that the geodetic coordinates read from a file of format NMEA 0183, are defined on ellipsoid WGS-84. If necessary the program recalculates coordinates to the coordinate system of a map on which objects are created.