Vectornav VN-100, User Manual

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UM001 43
rate and acceleration measurements straight from the IMU. The measurements have not been corrected
for bias offset by the onboard Kalman filter. These are equivalent to the UncompAccel and UncompGyro
fields in group 3.
Imu
accel[0] accel[1] accel[2] rate[0] rate[1] rate[2]
Byte
Offset
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Type float float float float float float
4.4.8 MagPres
The compensated magnetic, temperature, and pressure measurements from the IMU. The magnetic
measurement is given in Gauss, and has been corrected for hard/soft iron corrections (if enabled). The
temperature measurement is given in Celsius. The pressure measurement is given in kPa. This field is
equivalent to the Mag, Temp, and Pres fields in group 3.
MagPres
mag[0] mag[1] mag[2] temp pres
Byte Offset
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Type float float float float float
4.4.9 DeltaThetaVel
The delta time, angle, and velocity measurements. The delta time (dtime) is the time interval that the
delta angle and velocities are integrated over. The delta theta (dtheta) is the delta rotation angles
incurred due to rotation, since the last time the values were outputted by the device. The delta velocity
(dvel) is the delta velocity incurred due to motion, since the last time the values were outputted by the
device. These delta angles and delta velocities are calculated based upon the onboard conning and
sculling integration performed onboard the sensor at the IMU rate (default 800Hz). The integration for
both the delta angles and velocities are reset each time either of the values are either polled or sent out
due to a scheduled asynchronous ASCII or binary output. This field is equivalent to the DeltaTheta and
DeltaVel fields in group 3 with the inclusion of the additional delta time parameter.
DeltaThetaVel
dtime dtheta[0] dtheta[1] dtheta[2]
Byte Offset
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Type float float float float
DeltaThetaVel (continued)
dvel[0] dvel[1] dvel[2]
Byte Offset 16 17 18 19 20 21 22 23 24 25 26 27
Type float float float