Parallel Computation of Aerial Target Reflection of Background Infrared Radiation: Performance Comparison of OpenMP, OpenACC, and CUDA Implementations

The infrared (IR) signature of an aerial target due to the reflection of radiation from the Sun, the Earth's surface and atmosphere plays an important role in aerial target detection and tracking. As the background radiation from the Earth's surface, and atmosphere is distributed in the entire space and in a wide spectrum, it is time-consuming to obtain an aerial target's reflected radiation. This problem is suitable for parallel implementation to run on multicore CPU or many-core GPU because the reflection of background radiation incident from different directions in each spectral wavelength can be calculated in parallel. We consider three different parallel approaches: 1) CPU implementation using OpenMP (open multiprocessing); 2) GPU implementation using OpenACC (open accelerators); and 3) GPU implementation using CUDA (compute unified device architecture). An NVIDIA K20c GPU (with 2496 cores) and two Intel Xeon E5-2690 CPU (with 8 cores each) are used in our experiment. Compared to their single-threaded CPU counterpart, speedups obtained by OpenMP, OpenACC, and CUDA implementations are 15x, 140x, 426x, respectively. The result shows that GPU implementations are promising in our problem.