Trimble Outdoors AcutimeTM2000 Synchronization Kit manual Coordinate Systems, Tsip, Nmea

F Theory of Operation

F.4 Coordinate Systems

This section lists the coordinate system formats supported by the TSIP and NMEA 0183 protocols.

F.4.1 TSIP

In the default TSIP configuration, position is output in a Latitude- Longitude-Altitude (LLA) format based on a default datum, WGS-84. The LLA format can be easily converted by the host system to other coordinate systems using the appropriate translation algorithm. By sending the appropriate TSIP command, the smart antenna's position output can be changed to a Cartesian (XYZ) coordinate format. The datum used for LLA transformations can also be changed using the TSIP 8E packet. The smart antenna offers a selection of 179 datums, which are listed in Appendix A, Trimble Standard Interface Protocol.

The TSIP velocity output format is also three-dimensional. The default format is X-Y-Z with the option of an East-North-Up (ENU) coordinate format. Time tags on fix messages default to UTC (Universal Coordinated Time), but can be switched to GPS time by sending the appropriate TSIP command.

F.4.2 NMEA 0183

The NMEA 0183 protocol supports only LLA format and UTC time. If a custom datum is required, it can be set through TSIP using command 0x8E-15.

Acutime 2000 Synchronization Kit User Guide F-7