��̬������С����ģ�͵������㷨   总被引：6，自引：2，他引：4  

袁振超  沈云中  周泽波 《大地测量与地球动力学》2009,29(2):131-135

????????????????????????????????????????????????????С????????в???????,?????????????С???????????????????????????????????Tikhonov?????????????????????С??????????????????????????????????????????????Э????????????????????Fredholm???????????????????????????С????????????????????? ???????????????????????й?????????????????????????????  相似文献   

���ڶ�������򻯵Ŀռ�����ת���뾫�ȷ���   总被引：1，自引：0，他引：1  

陈正宇  刘春 《大地测量与地球动力学》2008,28(1):92-95

????????????????????????????,?????????????????????????????Bursa??????3??????????????????С?????????????????????е??????????????,???????????????????Χ??????????????????Morozov???????Tikhonov????????,???????????????????????????????????????????????????????????????????????????????С?????????????????????????????????????????  相似文献   

GPS���ٶ�λ�в�̬��������򻯿���ⷨ   总被引：1，自引：1，他引：0  

常志巧  郝金明  张成军  崔建勇 《大地测量与地球动力学》2008,28(3):83-86

???GPS?????λ??????????????????????????????????????????????M??????????????μ??????????????????????????????????????????????е????????????????????????÷??????п???????????????????????????  相似文献   

基于构造约束的波阻抗边界刻画          下载免费PDF全文

张宏兵  杨长春  尚作萍 《地球物理学进展》2007,22(3):817-825

通过边界保护正则化和约束反演,在反演的目标函数中引入各种先验信息约束,以解决波阻抗反演的病态问题和带限问题.为了克服波阻抗模型边界过于平滑,在反演中引入地层和断层等构造信息约束,并且通过调整地层分界面和断层处的正则参数值来实现构造约束.此外,采用各向异性扩散法进行平滑处理,改善反演结果.通过合成数据测试和实际资料反演,证明了本文提出的方法对刻画模型边界是有效的.  相似文献   

磁性下界面的正则化反演方法   总被引：1，自引：0，他引：1  

刘展  潘作枢 《物探与化探》1995,19(6):439-448

根据磁异常反演磁性介质下界面,属于非线性问题,一般很难直接求解.本文采用将非线性问题线性化措施,建立起线性离散磁模型,然后应用线性规划的正则算法,设计了迭代求解方案.该方法不要求已知界面起伏的平均深度,只要求假定界面是连续的及磁性沿横向变化.算法便于对解施行物理约束,具有收敛快,精度高的特点.  相似文献   

Simultaneous iterative time-domain sparse deconvolution to teleseismic receiver functions     

Christian Escalante  Yu J. Gu  Mauricio Sacchi 《Geophysical Journal International》2007,171(1):316-325

In this paper, we present a new approach to estimate high-resolution teleseismic receiver functions using a simultaneous iterative time-domain sparse deconvolution. This technique improves the deconvolution by using reweighting strategies based on a Cauchy criterion. The resulting sparse receiver functions enhance the primary converted phases and its multiples. To test its functionality and reliability, we applied this approach to synthetic experiments and to seismic data recorded at station ABU, in Japan. Our results show Ps conversions at approximately 4.0 s after the primary P onset, which are consistent with other seismological studies in this area. We demonstrate that the sparse deconvolution is a simple, efficient technique in computing receiver functions with significantly greater resolution than conventional approaches.  相似文献   

基于改进全变差正则化的GPR多尺度全波形双参数同步反演          下载免费PDF全文

王珣  冯德山  王向宇 《地球物理学报》1954,63(12):4485-4501

针对探地雷达（GPR）双参数全波形反演中电导率反演精度差、双参数存在串扰现象、反演计算量大、易陷入局部极值等问题.作者将具有多参数调节功能的L-BFGS算法引入到GPR时间域全波形反演中,它避免了对Hessian矩阵的直接存储与精确求解,减小了存储量和计算量.结合参数调节因子的选取,有效减小了同步反演时介电常数与电导率的串扰影响,在不降低介电常数反演精度的前提下,提高电导率参数的反演精度.通过在反演目标函数中加载改进全变差正则化方法,提高了反演的稳定性,使目标体边缘轮廓更加清晰.首先以简单模型为例,对比了单尺度反演与多尺度串行反演策略的优劣,说明多尺度串行反演有利于逐步搜索全局最优解;而开展参数调节因子的选取实验,说明合适的参数调节因子可以有效改善介质电导率的反演精度;测试了不同正则化的反演效果,表明改进全变差正则化能提高反演稳定性,显著降低模型重构误差.最后,分别对含噪合成数据和实测数据进行了反演测试,说明本文提出的多尺度、双参数反演具有较强的鲁棒性,能提供更丰富的信息约束,重构图像界面清晰、反演效果好.  相似文献   

均方误差意义下的正则化参数二次优化方法     

林东方  朱建军  付海强  张兵 《测绘学报》2020,49(4):443-451

Tikhonov正则化法是大地测量中应用最为广泛的病态问题解算方法之一。影响正则化法解算效果的重要因素是正则化参数,然而,最优正则化参数的确定一直是正则化解算的难题,如L曲线法确定的正则化参数具有稳定性好、可靠性高的优点,但存在过度平滑问题,导致正则化法对模型参数估值精度改善较小。本文从均方误差角度分析了正则化参数对模型参数估计质量的影响。基于奇异值分解技术,提出了由模型参数投影值分块计算均方误差的方法,避免了均方误差迭代计算,并基于均方误差最小准则给出了正则化参数优化方法,实现了对L曲线正则化参数的优化。数值模拟试验与PolInSAR植被高反演试验结果表明,正则化参数优化方法有效改善了正则化法解算效果,提高了模型参数估计精度。  相似文献   

Multiple Parameter Regularization: Numerical Solutions and Applications to the Determination of Geopotential from Precise Satellite Orbits   总被引：1，自引：0，他引：1  

Peiliang Xu  Yoichi Fukuda  Yumei Liu 《Journal of Geodesy》2006,80(1):17-27

Kaula’s rule of thumb has been used in producing geopotential models from space geodetic measurements, including the most recent models from satellite gravity missions CHAMP. Although Xu and Rummel (Manuscr Geod 20 8–20, 1994b) suggested an alternative regularization method by introducing a number of regularization parameters, no numerical tests have ever been conducted. We have compared four methods of regularization for the determination of geopotential from precise orbits of COSMIC satellites through simulations, which include Kaula’s rule of thumb, one parameter regularization and its iterative version, and multiple parameter regularization. The simulation results show that the four methods can indeed produce good gravitational models from the precise orbits of centimetre level. The three regularization methods perform much better than Kaula’s rule of thumb by a factor of 6.4 on average beyond spherical harmonic degree 5 and by a factor of 10.2 for the spherical harmonic degrees from 8 to 14 in terms of degree variations of root mean squared errors. The maximum componentwise improvement in the root mean squared error can be up to a factor of 60. The simplest version of regularization by multiplying a positive scalar with a unit matrix is sufficient to better determine the geopotential model. Although multiple parameter regularization is theoretically attractive and can indeed eliminate unnecessary regularization for some of the harmonic coefficients, we found that it only improved its one parameter version marginally in this COSMIC example in terms of the mean squared error.  相似文献   

中国煤层气选区评价标准探讨     

王一兵  田文广  李五忠  赵庆波  田立志 《地质通报》2006,(Z2)

煤层气选区评价关系到勘探的成功与否,是煤层气勘探研究最基础的工作。近年国内外煤层气成藏理论、开发技术的快速发展,使得低煤阶气藏、连续薄层气藏、高煤阶低渗气藏等都获得成功开发,大大拓宽了煤层气的开发领域。此前国内在中煤阶成藏优势论基础上建立的选区标准已不适合当前的要求。根据当前存在的问题,结合煤层气成藏类型、地质特点和技术现状,对中国煤层气勘探选区评价标准进行了研究,试图建立一套煤层气选区评价标准,以期对国内煤层气选区评价工作提供借鉴。  相似文献