A Study of the Effects of Background Subtraction on Occultation Imaging

One of the crucial steps in the occultation transform imaging technique involves the removal of the time-varying instrumental background. Previous versions of this imaging technique applied to BATSE data have used simple high-pass filtering to eliminate background variations on timescales longer than the typical duration of an occultation step (of order 10 s). We have investigated an alternative technique in which the imaging algorithm is applied to the residuals generated from fitting the raw data with a semi-empirical model of the background. Comparison of the resulting maps shows that the latter does not significantly improve imaging performance.