SAR Image Simulation of Complex Target including Multiple Scattering

Abstract

We present a GPU-based computation for simulating the synthetic aperture radar (SAR) image of the complex target. To be more realistic, we included the multiple scattering field and antenna pattern tracking in producing the SAR echo signal for both Stripmap and Spotlight modes. Of the signal chains, the computation of the backscattering field is the most computationally intensive. To resolve the issue, we implement a computation parallelization for SAR echo signal generation. By profiling, the overall processing was identified to find which is the heavy loading stage. To further accommodate the hardware structure, we made extensive modifications in the CUDA kernel function. As a result, the computation efficiency is much improved, with over 224 times the speed up. The computation complexity by comparing the CPU and GPU computations was provided. We validated the proposed simulation algorithm using canonical targets, including a perfectly electric conductor (PEC), dielectric spheres, and rotated/unrotated dihedral corner reflectors. Additionally, the targets can be a multi-layered dielectric coating or a layered medium. The latter case aimed to evaluate the polarimetric response quantitively. Then, we simulated a complex target with various poses relative to the SAR imaging geometry. We show that the simulated images have high fidelity in geometric and radiometric specifications. The decomposition of images from individual scattering bounce offers valuable exploitation of the scattering mechanisms responsible for imaging certain target features.

Fast SAR Image Simulation Based on Echo Matrix Cell Algorithm Including Multiple Scattering

“…The multiple backscattering subfields are vector-superimposed as the total multiple backscattering field of each discrete electromagnetic wave. The E s in Equation ( 17) can be expressed by Equation (24).…”

“…Dong et al proposed an improved ray tracing algorithm and combined it with the GO-PO/-PTD algorithm to improve the computational efficiency of the composite scattered field of a 3D ship target and the sea surface [23]. The multiple scattering echo simulation and imaging experiments based on CUDA were carried out using the shooting bouncing ray (SBR) method, which improved the efficiency and fidelity of the simulations [24]. Wu et al proposed a novel echo-based SAR image simulation method that comprehensively utilizes both SAR effective view and ray tracing algorithms, and improved the fidelity of simulated SAR images [25].…”

Bounding Volume Hierarchy-Assisted Fast SAR Image Simulation Based on Spatial Segmentation

“…Drozdowicz open-sourced a basic echo-based SAR image simulation infrastructure designed to facilitate collaboration on SAR image simulator development among interested researchers [13]. Chiang et al combined POs and GOs to carry out the target multiple backscatter field calculation, combined them with the frequency domain echo model to generate the original echo signals, acquired the tank SAR data set by focusing imaging processing, and achieved better simulation results [14]. Wu et al based on the physical illumination model of high-frequency ray theory, carried out the echo-based SAR image simulation on a typical military target to achieve some good simulation results, and then a fast simulation architecture based on the CUDA was established to effectively improve the efficiency of the SAR image simulation [15,16].…”

Improved framework of FMCW signal processing based on the PS end of FPGA

“…Song Chao [3] used multi-core digital signal processing (DSP) processors to process data in parallel to accelerate data processing speed, but this method used multiple DSP processors to increase power consumption and cost. Chiang, C. Y [4] et al used a Graphic Processing Unit (GPU) for radar echo data processing, and achieved an acceleration rate of 224 times through multithreaded parallel processing. However, serial data processors such as DSP have certain shortcomings in data processing by increasing the number of cores or enabling multiple threads to achieve parallel processing of serial processor data, thereby accelerating data processing speed.…”