提出采用一种与电磁波传播损耗相类似的指数衰减形式来描绘观测值权重随距离的变化,结合标准的统计反演算法来测试不同的观测值权值对反演速度与精度的影响.结果表明,指数衰减形式能较好地描绘观测值权值随距离的变化情况;其中衰减指数的选取是关键.合理地选取衰减指数可较好地改进反演的速度与精度.对于不同频率的电磁波,最优衰减指数是各不相同的.
Observation weight is generally not considered in the works on inversion ocean duct using radar echo.In order to solve the problem,an exponential expression similar to that of the electromagnetic wave propagation loss is used to describe change of observation weight with distance,and the standard statistics retrieval algorithm is used to test the effect of retrieval speed and precision caused by different observation weight.Experimental results show that the exponential expression can approprielly describe change of observation weight with distance,and the determination of loss index is of great importance.Reasonable observation weight can eviclently improve the retrieval speed and precision,and the optimal loss index is different for electromagnetic waves of different frequency.