基于非局部均值滤波的复杂地表区浮动基准面计算方法  

Method for calculating the floating datum in complex surface area based on NLM filter

作　　者：王胜春[1] 李进[1] 胡珊珊 WANG Sheng-chun;LI Jin;HU Shan-shan(SINOPEC Geophysical Research Institute,Nanjing 210014,China)

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院,南京210014

出　　处：《地球物理学进展》2018年第5期1985-1988,共4页Progress in Geophysics

摘　　要：在我国南方地区及西部地区等复杂地表区,采用平均静校正量法计算浮动基准面来进行地震资料叠前时间偏移处理时,剖面上会存在锯齿现象,因此,需要采用更加平滑的浮动基准面来进行处理.对于三维地震资料,本文提出采用非局部均值滤波计算平滑的浮动基准面静校正量,即通过非局部均值滤波算法在空间域平滑各CMP(Common Middle Point,共中心点)点的浮动面静校正量.该方法是一种比局部均值滤波方法更强壮的方法,能够更好的保护信号的结构信息,并且算法效果优于其他算法.应用实际资料,该方法计算的浮动基准面静校正量平滑,并且与平均静校正量法计算的浮动基准面静校正量形态相似,能消除地震剖面的锯齿现象,并且算法效果较好,证明该算法的合理性和有效性.In the south and midwest regions of our country,since the complexity of the surface condition,when we use the mean static correction method to calculate the floating datum for prestack time migration,there will be sawtooth in the seismic section,which is due to the sudden change of static correction. Therefore,we need a smoother floating datum to seismic processing. At present,there are average static correction method and the smooth surface method to calculate floating datum statics correction. The datum obtained by different methods is different. The paper presents a method of calculating the smoothing floating datum statics by using Non-local mean filter, the floating datum statics at each CMP（ Common Middle Point） point use Non-local mean filter algorithm to smooth in spatial domain,especially for 3-D seismic data. The basic principle of the non-local mean filter algorithm is similar to the mean filter algorithm,which requires the average value. But the Non-local mean filter adds the weight value of each point when calculating,so it can ensure that the influence between adjacent and large difference points is reduced when the average value is calculated in the frame. It also keeps a lot image edge details,so that the image looks clearer. In practical application,the first step is to calculate the statics of each shot point and detection point,then we can use the average statics method to calculate the average statics of each CMP point,at last we can use Non-local mean filter method to smooth the results of the second step. This method is more robust than the local mean filtering method,and can better protect the structural information of the signal,and the effect of the algorithm is better than other algorithms. The results show that the float datum statics calculated by this method is smoother and similar to the float datum statics calculated by the average static correction method. It can eliminate the sawtooth phenomena in the seismic profiles. The algorithm has a good effect,which proves the rationali

关 键 词：复杂地区 浮动基准面 平均地表法 非局部均值滤波算法 三维地震资料 

分 类 号：P631[天文地球—地质矿产勘探]