截断效应对NLCG反演的影响

线性反演要求有相当准确的背景介质模型的条件，这和地球物理问题中的实际情况相矛盾。而非线性反演不用求目标函数的偏导数，全局随机搜索模型空间的最优解的办法，避免了问题的线性化，由于非线性共轭梯度（NLCG）反演适应性较强、精度较高已被广泛的应用于地球物理的各个领域。在地球物理勘查工作中，最重要的一个因素就是如何优化数据，从数据源头上减少不适定性,提高勘探精度，有效地识别异常体；截断效应对数据影响很大，校正前后反演结果形成鲜明对比。进一步说明数据处理是解释结果的基础。

Effects of truncation effect on the inversion of NLCG

Linear inversion requires a fairly accurate background medium model, however, this is in contradiction to the real circumstances of geophysical problems. And the partial derivative of target function don't needs to be evaluated in nonlinear inversion algorithm , the globally random search optimization method of model space and the linearization of the problem is avoided, Due to the nonlinear conjugate gradient (NLCG) inversion strong adaptability and high precision ,it has been widely applied in various fields of geophysics. In geophysical exploration work, one of the most important factor is how to optimize data, from a data source the uncertainty of the solution is overcome and improve the exploration precision, effectively identify abnormal body; A great influence of truncation effect on data, the inversion result contrasts sharplyby comparing corrected and uncorrected.Further data processing is the basis of the interpretation results.