Noise calculation and analysis of a search coil magnetometer

For expertise on detecting very weak signal, search coil magnetometer is widely used in Magnetotellurics (MT). Unfortunately, noise is a primary factor affecting the sensitivity. In this work, noise model of the magnetometer is presented based on measured parameters, where transfer function affected by core eddy current loss is considered. Calculation is imposed on the model, and noise frequency response is obtained. After frequency dependent noise discussion, many suggestions to reduce the noises are presented. This work is useful for further study to obtain low noise search coil magnetometer.