GPS-20 Operating Manual
Rikaline
Rikaline
Marketing Corp.
5F-1, 125, Roosevelt Road, Sec. 5, Taipei, Taiwan 116
Tel: ++886 2 2934 5456 Fax: ++886 2 2934 4373 E-Mail:
web:
www.rikaline.com.tw
14
Name Example
Units
Description
Message ID
$GPVTG
VTG protocol header
Course 309.62
Degrees
Measured
heading
Reference T
True
Course
Degrees
Measured
heading
Reference M
Magnetic
(1)
Speed
0.13
Knots
Measured horizontal speed
Units N
Knots
Speed
0.2
Km/hr
Measured horizontal speed
Units
K
Kilometers per hour
Checksum *6E
<CR> <LF>
End of message termination
(1) SiRF Technology Inc. does not support magnetic declination. All “course over ground” data are
geodetic WGS84 directions.
4.2 RTCM Received Data
The default communication parameters for DGPS Input are 9600 baud, 8 data bits, stop bit, and no
parity. Position accuracy of less than 5 meters can be achieved with the GPS-20 by using Differential GPS
(DGPS) real-time pseudo-range correction data in RTCM SC-104 format, with message types 1, 5, or 9. As
using DGPS receiver with different communication parameters, GPS-20 may decode the data correctly to
generate accurate messages and save them in battery-back SRAM for later computing.
