基于DEM机载雷达图像仿真中地球曲率的影响

Influence of Earth Curvature in Airborne Radar Image Simulation Based on DEM

研究了雷达图像仿真中地球曲率对距离、遮蔽角、入射角计算效率和精度影响的问题。通过平面地面和球面地面下距离误差的分析和比较,确定两种方法的等效性;详细分析了平面地面的地形遮蔽算法产生误差的原因,通过对球面地面计算遮蔽角余弦值进行修正,建立了简化的遮蔽判断模型;考虑地面的高度起伏,给出了更为精确的入射角计算模型。通过仿真比较和实际工程应用的检验,证明了各个算法模型的准确性和合理性,能够产生更为逼真的仿真图像。

The problems of earth curvature effects on computational efficiency and accuracy of distance, defilade and incidence angle in radar image simulation were researched. The equivalence of distance computation based on the flat ground and spherical surface was proved by analyzing and comparing the distance error. The sources of error of flat ground founded terrain defilade computation were analyzed explicitly. An effective terrain defilade model was con- structed by modifying the cosine of defilade angle based on spherical ground. Considing the ground fluctuation, an accurate incident angle computation method was proposed. By simulation comparison and practical project applica- tions, the accuracy and rationality of each algorithm model were validated, it can generate more realistic simulation images.