基于航空重力梯度数据重建高分辨率局部重力场的径向基函数方法
The approach for high-resolution local gravity field recovery from airborne gravity gradient data based on radial basis functions
吴怿昊 1何秀凤 1罗志才 2吴云龙 3许闯 4宛家宽2
作者信息
- 1. 河海大学地球科学与工程学院,南京 211100
- 2. 华中科技大学精密重力测量国家重大科技基础设施地球物理研究所,武汉 430071
- 3. 中国地震局地震研究所地震大地测量重点实验室,武汉 430071
- 4. 广东工业大学土木与交通工程学院,广州 510006
- 折叠
摘要
基于径向基函数技术,研究了利用航空重力梯度数据重建局部重力场模型的方法,建立了泊松小波径向基函数和航空重力梯度张量之间的解析关系.以频率域变换和等效源方法为例讨论了不同梯度分量转换方法对重力场建模的影响,分析了基函数埋深深度对建模的影响.以澳大利亚珀斯Kauring试验场为例,采用实测航空重力梯度垂直分量构建了高分辨率重力场模型.结果表明,局部地形扰动对建模的影响较大,即使在平原或丘陵区域,也要考虑其影响.此外,不同梯度分量转换方法对于区域重力异常恢复的影响较小.再者,基函数埋深深度对建模影响较大;相比于采用重力数据建模而言,基于航空重力梯度数据求解时,基函数的适宜埋深深度更浅.联合航空重力梯度数据求解能显著提高重力场模型在高频和甚高频波段的分辨率和精度.与实测航空重力数据对比表明,利用航空重力梯度数据可构建分辨率约为0.15 km、精度优于1 mGal的重力场模型.
Abstract
This study investigates the approach for high-resolution regional gravity field recovery from airborne gravity gradient data based on radial basis function technique,where the analytical expressions between Poisson wavelets and airborne gravity gradient tensor are established.Based on the frequency domain transformation method and equivalent source method,we quantify the effects on regional gravity field modeling by using different approaches for the transformation of gravity gradient components.Moreover,the effects on regional solutions introduced by the choice of the depth of Poisson wavelets are quantified and investigated.We compute the local gravity field by using the vertical component of airborne gravity gradient tensor over the Kauring survey area,located east of Perth in Australia.Numerical experiments show that local topographical variation has significant effects on regional gravity field modeling,even over a plain or hilly region with relatively low elevation,which should be carefully considered.Moreover,the choice of approach for the transformation of gravity gradient components has marginal effects on regional gravity anomaly determination.In addition,the choice of the depth of Poisson wavelets has dramatic effects on regional solutions,and the optimal depth is much shallower compared to the case when gravity data is used for modeling.By combining the airborne gravity gradient data,the local gravity field can be significantly improved at high frequency and ultra-high frequency bands in terms of spatial resolution and accuracy.The computed gravity field model has a spatial resolution～0.15 km,the accuracy of which is better than 1 mGal when compared with the surveyed airborne gravity data.
关键词
航空重力梯度测量/垂直重力梯度/泊松小波径向基函数/局部重力场建模/航空重力数据Key words
Airborne gradiometry/Vertical gravity gradient/Poisson wavelet radial basis functions/Regional gravity field recovery/Airborne gravity data引用本文复制引用
基金项目
国家自然科学基金(42004008)
国家自然科学基金(41830110)
国家自然科学基金(41931074)
国家自然科学基金(41974096)
国家自然科学基金(42274004)
出版年
2024
NETL
NSTL
万方数据