Advanced Navigation Boreas D90 - External Depth Packet; Geoid Height Packet; RTCM Corrections Packet

11.4.32 External Depth Packet
External Depth is the measured distance below Mean Sea Level
External Depth Packet
Packet ID 53
Length 8
Read / Write Read / Write
Field # Bytes Offset Data Type Size Description
1 0 fp32 4 Depth (m)
2 4 fp32 4 Depth standard deviation (m)
Table 94: External Depth Packet
11.4.33 Geoid Height Packet
This packet provides the offset at the current location between the WGS84 ellipsoid and the EGM96 geoid
model. This can be used to determine the current height above mean sea level and also depth through the
following equations:
Height Above Mean Sea Level = WGS84 Height – Geoid Height
Depth = Geoid Height – WGS84 Height
WGS84 Height is the height at the current location in the System State packet, see 11.4.1 System State
Packet
Geoid Height Packet
Packet ID 54
Length 4
Read / Write Read
Field # Bytes Offset Data Type Size Description
1 0 fp32 4 Geoid height (m)
Table 95: Geoid Height Packet
11.4.34 RTCM Corrections Packet
This packet is used to encapsulate RTCM v3 correction data to be sent to the Boreas internal GNSS receiver for
DGPS or RTK GNSS functionality.
RTCM Corrections Packet
Packet ID 55
Length Variable, up to 255 bytes
Read / Write Write
Field # Bytes Offset Data Type Size Description
1 0 RTCM corrections data
Table 96: RTCM Corrections Packet
v1.2 Page 139 11 Oct 2022
Boreas Reference Manual • Advanced Navigation Packet Protocol