Motion MC hard and soft iron calibration static saved use in different location

[JChak.2]

Hi all,

I am using the ST library Motion MC for Magnetometer Calibration. The Library works really well but it always needs calibration in 8 figures to get a good status. 

We notice that The hard and Soft iron parameters are not changing from one calibration to another. 

Could these values be saved and used in other geographic locations without any 8 figures calibration since they are stable?

Please is there anyone who has tested this method. In our case we don't need the exact north orientation and it will be used in North-America

Many thanks and waiting for your reply,

[Miroslav BATEK]

Hard iron distortion arises from permanent magnets, magnetized iron or steel located nearby the magnetometer. This distortion remains constant and in fixed location related to the magnetometer for all heading orientations. Hard iron effect adds a constant magnitude field component along each magnetometer axis.

Soft iron distortion arises from the interaction of the Earth magnetic field and the material which surrounds the magnetometer sensor distorting the Earth magnetic field. The distortion magnitude and direction depend on the incident angle of the Earth magnetic field on the material. Hence, it varies with the magnetometer orientation.

You can save the calibration parameters and use them in different locations if the materials nearby the magnetometer remains the same.

[JChak.2]

Hi Miroslav,

Many thanks for these information, I will make some tests to confirm