IMPROVED METHOD FOR CALIBRATING FILTER VECTOR MAGNETOGRAPHS

We have developed a method to improve present techniques for calibrating linear and circular polarization signals in terms of the vector magnetic field from observations with a filter vector magnetograph. The method substantially reduces inaccuracies in deriving the inclination of the field from theoretical calibrations for inclination angles in the range 30 degrees-60 degrees. We outline the method and demonstrate its improved accuracy in applications to a model magnetic field and to actual magnetograph observations. We also demonstrate how the method affects the calculation of derived parameters using the example of the vertical electric current density.