Garmin GPSMAP 17 Технічні характеристики - Сторінка 25

4.3

Baud Rate Selection

Baud rate selection can be performed by sending the appropriate configuration sentence to the GPS sensor

as described in the $PGRMC Section

4.4

(This signal not available on the GPS 16A or GPS 17N.)

The highly accurate one-pulse-per-second (PPS) output is provided for applications requiring precise

timing measurements. The signal is generated after the initial position fix has been calculated, and the

signal continues until 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 sensor is referenced to the

pulse immediately preceding the NMEA 0183 RMC sentence.

The accuracy of the one-pulse-per-second output is maintained only while the GPS sensor can compute a

valid position fix. To obtain the most accurate results, the one-pulse-per-second output should be calibrated

against a local time reference to compensate for cable and internal receiver delays and the local time bias.

The default pulse width is 100 ms, however; it may be programmed in 20 ms increments between 20 ms

and 980 ms as described in $PGRMC Section

<13>.

Position accuracy of less than 5 meters can be achieved with the GPS 16/17 series products by using

Differential GPS (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 16/17 series products on COM 2. The

RTCM data must be received at the same baud rate as the COM 1 port. For details on the SC-104 format,

refer to RTCM Paper 134-89/SC 104-68 by the Radio Technical Commission for Maritime Services.

190-00228-20

4.1.3 Sensor Configuration Information

GPS 16/17 Technical Specifications

Page 21

(PGRMC), field <10>.

(PGRMC), field

Rev. C