System Description

System Description and Installation Manual for MXS ICD10004-01
© Sagetech Corporation 2018 Confidential Proprietary Export-Controlled Page 51 of 160
Vertical Figure of Merit (VFOM)
Byte Offset
Byte Name Field Description
58
VM0
Vertical Figure of Merit (VFOM)
All zeros – VFOM not available Else
Floating point distance (meters) that the computed altitude can be above or below the true
position with an accuracy of 95%.
59
VM1
60
VM2
61
VM3
Navigation Accuracy for Velocity (NAC
v
)
Byte Offset
Byte Name Field Description
62
NAV0 MSN
Bits 7-4
0x0
0x1
0x2
0x3
0x4
0x5-
0xF
NAC
V
(Most Significant Nibble)
The field is used to declare the accuracy of own-vehicle velocity. The value is
based on GPS figure of merit for horizontal velocity.
Unknown or ≥ 10 m/s
< 10 m/s
< 3 m/s
< 1 m/s
< 0.3 m/s
Reserved
LSN
Bits 3-0
Least Significant Nibble
Reserved
Table 0-15 GPS Navigation Data Message Example Data
Message Field Byte Values (original) Byte Message Content (Hex)
Start Byte
AA AA
Message Type
0x04 GPS Data Message 04
Message ID
An arbitrary number between 0 and 255 (inclusive) that uniquely identifies the message. 12
Payload Length
63 3F
P
A
Longitude
4543.6632Degrees
[ 31 32 31 32 39 2E 31 32 34 38 30