The Analysis of Data from Rotation Modulation Collimators

Abstract

Three methods of analysing data from rotation modulation collimators are discussed and only one is found to be at all satisfactory. A new algorithm has been developed which decreases the time required to perform this cross-correlation analysis considerably. Previous calculations of the image shapes resulting from the inclusion of weighting functions in the cross-correlation are corrected and the effect on image shape and intensity of rotation axis motion during an observation is described. Corrections to the image intensity have been derived for two special cases of spin axis motion and these are used to evaluate the results of two X-ray observations from sounding rockets. In both cases the intensity corrections are found to be in good agreement with the observations.