Abstract:

A fast algorithm of calculating scattering of background infrared radiation from non-lambertian aerial complex targets is presented. The sky and earth background infrared radiation are calculated by using a Modtran software. The surface of the target is partitioned into triangular facets and hidden by detection direction. Threads are partitioned by the incident direction of background light and run in the kernel of the graphic processing unit (GPU). Based on the five parameters bidirectional reflectance distribution function (BRDF) model, scattering intensity of background infrared radiation caused by visible facets from a direction is computed in every thread. The obtained results of all visible facets are weighted and averaged to obtain scattering intensity of the complex target surface. The comparison results of the central processing unit (CPU) calculation and GPU parallel calculation of an aircraft target shows that the GPU parallel calculation improves more than one hundred times.