© 2022 COSPARThis study examines geomagnetic storm conditions for attitude estimation of a spacecraft having magnetometers with various measurement noise levels at low Earth orbit. The geomagnetic field models are introduced by taking the external field effects into account. It is important to discuss the limitations of the models and the measurements that are being used. Therefore, the external effects are evaluated under different noise levels of magnetometer to determine and discuss the suppression level caused by the noise levels in a general framework. External magnetic field effects are examined by the ratio to noise under various magnetometer standard deviations up to 300 nT. An analysis is carried out for attitude estimation using Kalman-type filter in order to determine what noise level is acceptable on a particular sensor with a specified attitude requirement, magnetic field model, and space weather conditions. This study indicates that external magnetic fields are vital for establishing attitude processes based on magnetometers with varying noise on which the spacecraft relies for accuracy.