System Description

SystemDescriptionandInstallationManualforRangeFinder ICD1000001
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8.3.5 GPSNavigationDataMessage:Type0x04
TheGPSDataMessage:
ProvidestheRangeFinderwithGPSdata,including‐latitude,longitude,height,groundspeed,track,
andvalidity,accuracyandintegritymeasurements.
Ifused,shouldbesentatregularintervals(betweenoneandfivetimespersecond),typicallyatthe
nominalupdaterateoftheGPShardware.
Note:
IftheNavigationReceiverVali dbit(intheHemispherebyte)is0, thenalldatafields
in the message are required to be valid, except for Time of Fix (which can be set to all
spaces if it is not valid). If the Navigation Receiver Valid bit is 1, all data fields are
consideredinvalid;sendingthemessagewiththeNavigationReceiverValidbitsetto1has
thesameeffectasnotsendingthemessage.
An overview of the GPS Navigation Data Message is shown in Table 813.Table 814 provides the detailed
messagedefinition.AnexampleoftheGPSNaviga tionDataMessageisfoundinTable815.
Table813GPSNavigationDataMessagePayloadStructureOverview
PayloadIndex MessageField Numberbytes
00 GPSLongitude 11
11 GPSLatitude 10
21 SpeedOverGround 6
27 GroundTrack 8
35 Hemisphere/DataStatus 1
36 TimeofFix 10
46 Height 4
50 HPL 4
54 HFOM 4
58 VFOM 4
62 NAC
V
1