Nobody Inversion Using Data Segments in Crosshole Electromagnetic Tomography
Wu Jianping Feng Rui (Institute of Geophysics,SSB,Beijing,100081)
In this paper the rectangular grid-based ray tracing algorithm was given.Ininversion we often find when there exist strong absorption anomalies between two wells,the result of inversion is usually far from the real situation.In this paper we presents anew method to resolve the problem.We divided the observed data into several segments asits value.Firstly,we use the strongest signals to inverse the small absorbtion coefficientsas background medium to the next step.Secondly,keeping the absorption coefficients ofbackground unchanged or with strict restrain,we use the weaker signals to inverse thelarger absorption coef(?)icients.In this way,all coefficients between two wells we needed canbe obtained.In practical work,the results obtained by this method is usually much betterthan the others when there exists strong absortion anomalies between two wells.
【Fund】： 国家地震局地球物理研究所论著 No.93A0053.