一种电大尺寸组合体散射的快速计算方法

采用自适应多层快速多极子算法分析电大尺寸组合体的雷达散射截面。推导了组合体表面的积分方程,通过将基函数和权函数分别用不同空间位置上的点源函数展开,自适应多层快速多极子算法实现了阻抗积分的快速计算,通过采用射线传播法,远场近似和对称性计算法则使转移因子的计算效率大大提高,所有转移过程可由快速傅里叶变换计算完成。这种算法计算组合体散射时所需的计算时间和内存显著降低,且数值计算结果和实际测试结果吻合良好。

A Fast Calculation Method of Electrically Large-size Composite Targets Scattering

Radar Cross Section （RCS） of the electrically large-size composite target is analyzed by using an adaptive multilevel fast multipole algorithm （AMLFMA）. The integral equation on the composite target surface is deduced. The base and the weight functions are expanded respectively by using Dirac function in different space posi- tion. The fast calculation of impedance integration is implemented by using adaptive multilevel fast multipole algo- rithm. The calculation efficiency of transfer factor is improved greatly by adopting ray-propagation method, far-field approximation and symmetric calculating rule. All the transfer process can be implemented by calculation with fast Fourier transformation （FFT）. The needed calculation time and memory are decreased significantly by using this algorithm to calculate the composite target scattering, and the good agreement between the numerical computed and real measured results is obtained.