The Ørsted Satellite Project

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DETERMINING THE DIRECTION OF A GEOMETRICAL/OPTICAL REFERENCE AXIS IN THE COORDINATE SYSTEM OF A TRI-AXIAL MAGNETIC SENSOR

 

Primdahl, F. (1,3), P. Brauer (1), J.M.G. Merayo (1), J.R. Petersen (3), and T. Risbo (2)

 

  1. Technical University of Denmark, Department of Automation, Building 327, DK-2800 Lyngby, Denmark. Phone: +45 4525 3445, Fax: +45 45 88 71 33, E-mail: fp@iau.dtu.dk
  2. Copenhagen University, Niels Bohr Institute, Department of Geophysics, Juliane Maries Vej 30, DK-2100 Copenhagne Ø, Denmark.
  3. Danish Space Research Institute, Juliane Maries Vej 30, DK-2100 Copenhagen Ø, Denmark.

 

Abstract. The orthogonal reference coordinate system axes of a calibrated magnetic vector field sensor are related to the instrument digital output vector U by the calibration matrix [C] and the offset vector O. This reference coordinate system must then in addition be related to (at least) two externally accessible optical or geometrical axes in order to be able to determine the precise orientation of the magnetic sensor reference coordinate axes in an external system. Two methods for determining an optical/geometrical axis in the sensor reference coordinates are discussed:

  • Using a tri-axial coil facility to measure the sensor orientation in two different positions, rotated about a fixed optical (or geometrical) reference axis.
  • In the Earth's field the magnetometer sensor is rotated about a fixed geometrical axis into a number of (at least 3) positions.

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