航空瞬变电磁一维正演的连分式算法研究

Research on continued fraction algorithm for calculating 1-D airborne transient electromagnetic

针对快速Hankel变换精度不高的问题,改进了连分式算法,使之能够计算余弦变换,并与快速汉克尔变换算法作了比较,结果表明:无论是计算积分收敛或核函数快速衰减的余弦变换,还是计算核函数震荡增加的发散型Hankel积分时,连分式算法都具有精度高、计算稳定的特点,而滤波法计算核函数震荡增加的发散型Hankel积分的误差较大.最后,把连分式算法应用于航空瞬变电磁一维正演模拟计算,得到了满意的瞬变响应,其计算精度、速度和稳定性很好,为瞬变电磁模拟计算提供了一种新的计算方法.

In terms of low accuracy of fast Hankel transform algorithm, modified - continued fraction algorithm was used to simulate sine or cosine transform, and compared the results with the digital filter （DF） algorithm＇ s , which shows that when dealing with fast convergent sine transforms or divergent transforms that DF method failed to calculate accurately here, the modified-continued fraction algorithm has always a high precision and quite stable results. Then some typical ATEM 1 - D modeling problems were calculated by this algorithm, and the results , which was compared with that by DF algorithm that was ]based on fast Hankel transform, were quite satisfactory in terms of its accuracy, speed and stability, the result ,~how that this algorithm is a new efficiency method for calculation of transient electromagnetic modeling .