基于Laplace方程的垂线偏差法反演全球海域重力异常  

Inversion of global marine gravity anomalies with vertical deflection method deduced from Laplace equation

作　　者：张胜军[1] 李建成[2] 孔祥雪[3] ZHANG Shengjun;LI Jiancheng;KONG Xiangxue(School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;School of Geodesy and Geomatics, Wuhan University,Wuhan 430079,China;Liaoning Earthquake Agency, Shenyang 110031, China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819 [2]武汉大学测绘学院,湖北武汉430079 [3]辽宁省地震局,辽宁沈阳110031

出　　处：《测绘学报》2020年第4期452-460,共9页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(41804002);中央高校基本科研业务专项资金资助项目(170103009);武汉大学地球空间环境与大地测量教育部重点实验室开放基金(17-01-04)。

摘　　要：海洋重力场模型反演的质量主要依赖于采用测高数据的精度、空间分辨率和数据分布密集程度。本文联合Geosat GM/ERM、ERS-1 GM/ERM、TOPEX/Poseidon、Envisat、Cryosat-2、Jason-1 ERM/GM和SARAL/AltiKa等多种测高观测数据集,深入比较了多种波形重跟踪算法的效果,回波数据重跟踪处理后的沿轨海面高标准差。统计表明,Sandwell算法优于MLE-4算法、Davis阈值法、改进阈值法和β参数拟合法;基于不同测高数据波形重采样的结果给出了沿轨海面梯度计算中低通滤波的参数选择方法,并采用Sandwell提出的垂线偏差法,反演了全球海域1′×1′的重力场模型。检核表明,反演结果与DTU13和SIO V23.1模型检核的差值均方根分别为3.4、1.8 mGal,与NGDC船测数据的检核精度为4~8 mGal,且本文模型在部分典型海区内精度更优。The quality of marine gravity field derived from satellite altimetry mainly relies on denser data coverage,enhanced spatial resolution as well as improved range precision.In this study,a comparison of application effect for several waveform retracking methods is firstly executed on the basis of multi-satellite altimetry dataset sincluding Geosat GM/ERM,ERS-1 GM/ERM,TOPEX/Poseidon,Envisat,Cryosat-2,Jason-1 ERM/GM and SARAL/AltiKa.According to the statistics of along-track standard deviation,the two-step retracker proposed by Sandwell is superior to other retrackers such as MLE-4,threshold,advanced threshold,andβ-5 parameter fitting method.Tuned parameters for certain low-pass filtersare given within the resampling procedure for each altimeter mission in order to calculate accurate along-track slopes.Then a 1′×1′global marine gravity field model is inversed based on the remove-restore procedure by introducing the EGM2008 as reference model.The root mean squares(rms)of difference are respectively 3.4 mGal and 1.8 mGal by comparing with DTU13 and SIO V23.1 model.Meanwhile,the comparison with ship-measured data results a RMS range of 4~8 mGal,while better coincidence shows up in typical ocean areas.In summary,both the comparisons indicate that the new model has a comparable accuracy level with DTU13 and V23.1 at designed 1′×1′grid interval.

关 键 词：卫星测高 波形重跟踪 垂线偏差 重力异常 

分 类 号：P228.3[天文地球—大地测量学与测量工程]