An Attempt on Geomagnetic Survey using Smartphone Magnetometer

Abstract

The authors present an attempt to evaluate the utilization of magnetometer sensors of the smartphones on geophysical investigations related to geomagnetic fields. The Smartphones is equipped with a magnetometer sensor that can be used as an alternative instrument for geomagnetic surveys which is less expensive and more accessible compared to industrial grade magnetometer. This experiment used an Android-based smartphone magnetometer supported by the Phyphox application. Industrial-scale magnetometer Geometrics PPM G-857 also used as a comparison and data control. The acquisition is conducted in fields where underground utilities of gas pipelines is situated and those pipelines is expected to be the source of subsurface anomalies. The results showed that the Smartphone magnetics anomaly (TMI & RTP) maps gave similar trend compared to the Geometrics PPM G-857, despite of difference value of anomaly up to 1000 nT. The smartphone results are also portrayed higher frequency anomalies, this could be understood that the electronic component of smartphone itself might be the source of noise. The Gaussian filter is applied such that anomalies with wavelength spectrum () less than 3m (higher frequency) will be damped. The anomaly filtering might improve the anomaly response of gas pipelines which is described as high magnetic anomaly. Although the anomalous response of the smartphone magnetometer is not as accurate as the PPM G-857 magnetometer, this experiment successfully confirms the ability of the magnetometer smartphone to be used for geomagnetic surveys.