Accuracy estimation of the magnetometer measurements onboard Service Module of ISS

There is a three-component magnetometer SM-8M onboard Service Module of ISS. It means to solve problems concerned with the station attitude motion and monitoring environment in some space experiments. Successful operation of the magnetometer depends on how precise its measurements adjust with the part of the Earth Magnetic Field that is presented by IGRF model. If the measurements after its appropriate correction deviate from IGRF model less the a few hundreds $\gamma$, then the magnetometer operates acceptably. Such errors correspond to the magnetometer accuracy and field variations that are not taken into account in IGRF model. To calculate the deviations one has to know the station position in its orbit and the magnetometer attitude. If they are known then one can specifies the const biases in the measurements, the transition matrix from Service Module structural coordinate system to the proper magnetometer coordinate system, and Poisson coefficients that characterize the influence of the proper station magnetic field in magnetometer readings. This paper contains results of magnetometer testing carried out in the way above. The root-mean-square deviation of measurements from IGRF model is in the limits $200 \div 300 ~\gamma$ for each vector component of the field.