[Rock-dev] Standard unit for IMU mangetometer values?

[Leif Christensen]

Hi,

do we have a standard unit / convention for magnetometer readings?

In the xsens_imu and imu_xsens drivers, we are just forwarding the
values from the xsens, which confirms to no standard at all (arbitrary
unit with 1 being the magnetic field strength at calibration time in
Enschede, Netherlands). The stim300, imu_kvh_1750 have no magnetometer
inside.

Some are using Tesla, some Gauss (10^-4 T).

Most of the time we are interested in the magnetic flux density of the
(distorted) earth magnetic field, which ranges from 30µT (equator) to 60
µT (pole).

Apart from being the derived SI unit, Tesla is a little bit unhandy for
these ranges, I think. But if we have a standard there, I would go with
that. If not, I would either propose µT or Gauss.

Total magnetic field strength today in Bremen (IGRF11 model):
49429.8 nT
49.4298 µT
0.494298 G
0.0000494298 T

LG,
Leif
-- 
 Leif Christensen

 DFKI Bremen
 Robotics Innovation Center
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 Phone: +49 (0)421 17845-4149
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 E-Mail: leif.christensen at dfki.de

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