COMPTEL skymapping: a new approach using parallel computing
  Large-scale skymapping with COMPTEL using the full survey database presents challenging problems on account of the complex response and time-variable background. A new approach which attempts to address some of these problems is described, in which the information about each observation is preserved throughout the analysis. In this method, a maximum-entropy algorithm is used to determine image and background simultaneously. Because of the extreme computing requirements, the method has been implemented on a parallel computer, which brings large gains since the response computation is fully parallelizable. The zero level is left undetermined in this method. Results using data from 7 years of COMPTEL data are presented. 
A. W. Strong, H. Bloemen, R. Diehl, W. Hermsen, V. Schoenfelder