A Three Axis Magnetometer For use in a Small Satellite

This paper deals with a construction of a three axis magnetometer for use in a small satellite. It is necessary to know the magnetic field around the satellite for an attitude stabilisation and for propulsion. A minimal weight, size and power consumption are the most critical properties of this construction. The magnetic flux has to be measured in an 8-bit resolution. Two small packages with magnetoriesistive sensors from HONEYWELL are used. One package measures magnetic flux in the axis X and Y, and second in the axis Z. The microcontroller is used for data processing, sensors setup and for communication over central bus. Other units in the satellite are able to read the results of the magnetic field measurement over this bus. The software in the microcontroller has to remove any noise and electrical offsets from the data, improves the immunity to an impulse disturbances and a magnetic offsets caused by other electric circuits in the satellite. Construction of this magnetometer is one part of a large project, whose aim is to build Czech amateur satellite compatible with the CubeSat technology.