Modeling the DMSP and CRRES Dosimeters Using the Path Length Distribution Method

Abstract : The Path Length Distribution method is used to model the dosimeter instruments used aboard the DMSP and the CRRES satellites. The Monte Carlo methods used to compute the path length distributions for the isotropic, mirror plane, and sin(N) alpha pitch angle proton angular distributions (N = 4, 6, 8 and N = 999 (for comparison with the Mirror Plane Distribution)) are described. The path length distributions are used to compute the instrument proton flux and dose count response functions and geometric factors for power law and Maxwellian proton energy spectra. Comparisons of the geometric factor computations using the path length method with the infinite slab approximation and the truncated infinite slab path length distribution are also made. Tables and graphs of modeled instrument performance are provided.