Magnetic imaging system in smartphones based on built-in magnetometer

Summary form only given. Magnetometers have recently become a built-in feature in most tablets and smartphones around the globe. The sensor is usually based on GMR/AMR (Giant/ Anisotropic Magneto Resistance) materials, which are produced as magnetometer integrated circuits that cost less than USD 1. Although they are not as sensitive as the magnetometers used in the geomagnetic survey, their omnipresence and low price tag, as well as the readily available computing power of tablets/smartphones, drive our interest to develop a subsurface imaging system based on built-in magnetometers.