Short-Time and High-Precision Measurement Method for Larmor Frequency of Marine Overhauser Sensor

The measurement accuracy of the Larmor frequency of the Overhauser magnetic sensor directly determines the magnetic accuracy of the Overhauser magnetometer. We propose a multichannel interpolation method for marine magnetic measurements, addressing specifically the deficiencies in traditional measurement methods. The quantization error of the count value of the standard signal is greatly reduced using the delay chain interpolation technique. Also the influence arising from the phase error is weakened through channel expansion. In addition, we also design a test platform and conduct two sets of field contrast tests, the test results showing that the proposed method not only improves the precision of the frequency measurement by about three times but also improves the resolution and lowers the noise level of the system.