Revision history

May 11, 2016. First issue.
July 02, 2018. The definition of the timestamp is updated.

KM Binary sensor data, version 1, length 132 bytes

Data field	Content	Format	# of bytes
Start ID	#KMB	char	4U
Datagram length	132	uint16	2U
Datagram version	1	uint16	2U
UTC seconds	s	uint32	4U
UTC nanoseconds	ns	uint32	4U
Status word	See 1)	uint32	4U
Latitude	deg	double	8F
Longitude	deg	double	8F
Ellipsoid height	m	float	4F
Roll	deg	float	4F
Pitch	deg	float	4F
Heading	deg	float	4F
Heave	m	float	4F
Roll rate	deg/s	float	4F
Pitch rate	deg/s	float	4F
Yaw rate	deg/s	float	4F
North velocity	m/s	float	4F
East velocity	m/s	float	4F
Down velocity	m/s	float	4F
Latitude error	m	float	4F
Longitude error	m	float	4F
Height error	m	float	4F
Roll error	deg	float	4F
Pitch error	deg	float	4F
Heading error	deg	float	4F
Heave error	m	float	4F
North acceleration	m/s2	float	4F
East acceleration	m/s2	float	4F
Down acceleration	m/s2	float	4F
Delayed heave:	-	-	-
UTC seconds	s	uint32	4U
UTC nanoseconds	ns	uint32	4U
Delayed heave	m	float	4F

For calculation of the doppler effect at the transducer locations (needed in FM chirp mode), the following data is mandatory: Roll, pitch, heave, heading, 3 axis rates and velocities. The update rate should be minimum 100 Hz. Delayed heave is strongly recommended (if this improves the heave quality). Note that the delayed heave is based on the same reference point as regular heave.

Definitions

Data field	Description
Data format	Little endian (the least significant byte is transmitted first). Float is according to IEEE - 754.
Dgm length	The total number of bytes in the datagram.
Dgm version	The version is incremented if the datagram format is changed.
Timestamp format	Epoch 1970-01-01 UTC time
Position and height	At user defined sensor reference point. Position in decimal degrees.
Latitude	Negative on Southern hemisphere.
Longitude	Negative on Western hemisphere.
Height	Positive above ellipsoid.
Positive roll	Port side up.
Positive pitch	Bow up.
Positive heave	Downwards, at user defined sensor reference point.
Heading	True North.
Error fields	Sensor data quality: RMS, -1 = not implemented

1) Status word

One bit per status info, 1= active

Bit #	Invalid data:
0	Horizontal position and velocity
1	Roll and pitch
2	Heading
3	Heave and vertical velocity
4	Acceleration
5	Delayed heave

Bit #	Reduced performance:
16	Horizontal position and velocity
17	Roll and pitch
18	Heading
19	Heave and vertical velocity
20	Acceleration
21	Delayed heave