Garmin GPS 15L Technical Specifications

Contents

Garmin GPS 15L Technical Specifications Manual pdf 24 page image

190-00266-01 GPS 15H & 15L Technical Specifications Rev. DPage 204.3 BAUD RATE SELECTIONBaud rate selection can be performed by sending the appropriate configuration sentence to the GPS sensoras described in the $PGRMC section 4.1.3, field <10>.4.4 ONE-PULSE-PER-SECOND (PPS) OUTPUTThe highly accurate one-pulse-per-second (PPS) output is provided for applications requiring precisetiming measurements. The signal is generated after the initial position fix has been calculated and continuesuntil power down. The rising edge of the signal is synchronized to the start of each GPS second.Regardless of the selected baud rate, the information transmitted by the GPS 15H & 15L is referenced tothe pulse immediately preceding the NMEA 0183 RMC sentence.The accuracy of the one-pulse-per-second output is maintained only while the GPS 15H & 15L cancompute a valid position fix. To obtain the most accurate results, the one-pulse-per-second output should becalibrated against a local time reference to compensate for cable and internal receiver delays and the localtime bias.The default pulse width is 100 ms, however; it may be programmed in 20 ms increments between 20 msand 980 ms as described in $PGRMC section 4.1.3, field <13>.4.5 RECEIVED RTCM DATAPosition accuracy of less than 5 meters can be achieved with the GPS 15H & 15L by using DifferentialGPS (DGPS) real-time pseudo-range correction data in RTCM SC-104 format, with message types 1, 2, 3,7, and 9. These corrections can be received by the GPS 15H & 15L on COM 2. The RTCM data must bereceived at the same baud rate as the COM 1 port. For details on the SC-104 format, refer to RTCM Paper134-89/SC 104-68 by the Radio Technical Commission for Maritime Services.