
ST2276
Scientech Technologies Pvt. Ltd.
33
Note :
Some autopilots, Robertson in particular, misinterpret "bearing from origin to
destination" as "bearing from present position to destination". This is likely due to the
difference between the APB sentence and the APA sentence, for the APA sentence
this would be the correct thing to do for the data in the same field. AP A only differs
from APB in this one field and APA leaves off the last two fields where this
distinction is clearly spelled out. This will result in poor performance if the boat is
sufficiently off-course that the two bearings are different.
$GPAPB, A, A, 0.10, R, N, V, V, 011, M, DEST, 011, M, 011, M*82
where :
APB Autopilot format B
A Loran-C blink/SNR warning, general
warning
A Loran-C cycle warning
0.10 cross-track error distance
R steer Right to correct (or L for Left)
N cross-track error units - nautical
Miles (K for kilometers)
V arrival alarm - circle
V arrival alarm - perpendicular
011, M magnetic bearing, origin to destination
DEST destination waypoint ID
011, M magnetic bearing, present position to destination
011, M magnetic heading to steer (bearings could True as 033, T)
$GPBOD :
Bearing Origin to Destination
Eg. BOD, 045. T, 023. M, DEST, START
045., T bearing 045 degrees True from "START" to "DEST"
023., M beraing 023 degrees Magnetic from “START” to “DEST”
"DEST" destination waypoint ID
START origin waypoint ID
Example 1: $GPBOD, 099.3, T, 105.6, M, POINTB,*01
Waypoint ID: "POINTB" Bearing 99.3 True, 105.6 Magnetic. This sentence is
transmitted in the GOTO mode, without an active route on your GPS.
HiK-Consulting