一种高精度初至波二次定位新方法——搜索法
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摘要
目前,检波点的二次定位成果已成为衡量滩浅海地区地震勘探数据采集质量的重要指标。通常检波点的二次定位方法分为声纳系统定位和初至波定位两种。传统的初至波定位法——"圆圆相交定位方法"要获得较高的定位精度,就必须在算法的实现过程中充分考虑由于圆的位置关系而产生的定位误差而且必须对要参加圆圆相交运算的圆进行精细的筛选,这一方面大大降低了运行效率,另一方面由于算法缺陷而产生的定位误差不能完全消除,影响了二次定位的定位精度。文中围绕如何提高初至波二次定位的精度和数据处理速度,提出了"搜索法"初至波二次定位方法,该方法的实现思路是:在检波点的一次定位点附近区域的网络中找到初至拉平效果最好的网格节点,这个点就是要求取的检波点的二次定位点。文中对"搜索法"的定位精度和运算效率进行了理论测试和实例分析,结果表明,"搜索法"具有很好的各向同性效果,定位结果与声纳定位结果具有很好的一致性,运算速度提高了5倍,定位精度也有较大的提高。
Currently,the secondary positioning results of geophones have become an important index evaluating seismic data explored in beach and shallow sea.Generally,the secondary positioning methods of geophone can be divided into sonar system positioning and first break positioning.The traditional first break positioning is positioning by circle intersecting circle,which should fully consider the positioning errors produced from circle positions in the process of algorithm and finely select the circles that participate the operation of circle intersecting circle to acquire the high positioning precision,which greatly reduced the operational efficiency,since the positioning errors can't be totally eliminated because of the shortcomings of algorithm,resulted in influence on positioning precision of secondary positioning.Around the issue how to improve the precision and data processing speed of first break secondary positioning,the paper presented the search method the idea of which is that finding the node of grid best aligning the first break on the grid of region nearby first positioning point of geophones,which are exactly the secondary positioning point of the computed receiver point.The paper carried out the theoretical test and case analysis for the positioning precision and operation efficiency of the method,which showed that the search method has good isotropic effect,and the positioning results have good consistencies with sonar positioning results;operation speed has been raised by 5 times and the positioning precision has also been greatly improved.
Currently,the secondary positioning results of geophones have become an important index evaluating seismic data explored in beach and shallow sea.Generally,the secondary positioning methods of geophone can be divided into sonar system positioning and first break positioning.The traditional first break positioning is positioning by circle intersecting circle,which should fully consider the positioning errors produced from circle positions in the process of algorithm and finely select the circles that participate the operation of circle intersecting circle to acquire the high positioning precision,which greatly reduced the operational efficiency,since the positioning errors can't be totally eliminated because of the shortcomings of algorithm,resulted in influence on positioning precision of secondary positioning.Around the issue how to improve the precision and data processing speed of first break secondary positioning,the paper presented the search method the idea of which is that finding the node of grid best aligning the first break on the grid of region nearby first positioning point of geophones,which are exactly the secondary positioning point of the computed receiver point.The paper carried out the theoretical test and case analysis for the positioning precision and operation efficiency of the method,which showed that the search method has good isotropic effect,and the positioning results have good consistencies with sonar positioning results;operation speed has been raised by 5 times and the positioning precision has also been greatly improved.
引文
[1]杨正华,常军.海底电缆地震中二次定位法的探讨.石油物探,2002,41(3):330～333
[2]韩立强,常稳.海底电缆初至波二次定位技术的应用.石油物探,2003,42(4):501～512
[2]韩立强,常稳.海底电缆初至波二次定位技术的应用.石油物探,2003,42(4):501～512
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