A magnetometer is an electronic device capable of measuring magnetic fields or magnetic dipole moment. Magnetometers are widely used for measuring the Earth’s magnetic field, in geophysical surveys, to detect magnetic anomalies of various types. If you fancy building your very own DIY magnetometer you may be interested in a Arduino project published to the Instructables website by maker Markus Opitz. His magnetometer costs less than €50 to build and provides an easy way to survey the land around you.
Build your very own DIY magnetometer
“What is under the ground? What is under my property? I have studied geography, I have an old house that has been standing as a farm for over a hundred years on a wide piece of land and I like to work with Arduino & Co. So I build my own magnetometer.
With a magnetometer you can map archaeological structures that cause anomalies in the Earth’s magnetic field. They work best in large open areas and are (hopefully) sensitive enough to pick up the slight changes in the earth’s magnetic field over a particular spot. Magnetometer mapping can reveal patterns by recording the magnetic properties of ferrous elements in the soil or those left behind after human activity.”
The idea is to plot the magnetometer data on a map, visualise differences and therefore get an insight into the underground. For example, magnetometry was used in the exploration of the ground around Stonehenge in England. However, they have better sensors there and drag them across the field with a quad. Two years ago I already walked over my property with a single magnetometer sensor, recorded GPS data and magnetic values and transferred them to a custom Google Maps map.
The result was interesting, but not very meaningful. For more data, I would have had to walk a lot more in a more dense grid. So how about seven sensors side by side? Do I then need 7 GPS receivers? No, I can calculate the position of the sensors starting from the center coordinate if I have a compass that shows the current direction.”