改进型SIRT法进行电磁波CT反演应用研究

Study of Electromagnetic Waves CT Inversion in Improved SIRT Method

利用声波、地震波CT中广泛应用的SIRT法对BPT法进行改进,用"dij/li"替换"dij"作为第i条射线在第j个网格中的权值,使那些较小的dij(dij=li)在传统的BPT法中权值微小,而在改进型BPT法中却有最大的权值,用其计算结果作为CT反演计算的初值,同时将BPT法融合到SIRT法中去,使射线与网格符合"近则优"的原则,称之为改进型SIRT法,能起到有效地压制野外资料的外界干扰影响。该方法于电磁波CT在生产实践应用中取得显著成效。

This paper adopts SIRT method which has been widely used in acoustic and seismic wave CT technology to improve the BPT method. With ＂dij/li＂ replacing ＂dij＂ as the i rays of the j grid in the weight, those smaller do （dij = li） in the traditional BPT become little in weight, but in the improved BPT, the weight is the greatest. By using the results as the initial CT inversion calculation, BPT will be integrated into law SIRT to law, so the ray and grid will go with the principle that ＂ the near is good ＂ known as the improved SIRT method. The method in the production of electromagnetic waves CT achieved remarkable results.