Comparison of geomagnetic field from models and satellite observations for attitude determination purposes

In this study, two geomagnetic field models, T89 and IGRF-11 models are compared with the satellite observations Total magnetic field, magnetic field components and angle between the model and observed data are used for comparisons. The differences are important for the satellite attitude determination systems where the total magnetic field and the angle between the model vector and the observed vector are essential. T89 model differs from the observations by an amount of (0.1-0.3)×10⁴ nT in the total magnetic field. Differences increase when the geomagnetic activity occurs. Differences in the angle can range from 20 to 30^o. Differences are found to be the highest in By component and the lowest in B_z component Comparisons are also made between the IGRF and T89 models. Two models are found to be the most different during the high geomagnetic activity periods.