摘要
本文通过分析陆地实测空间重力异常数据、海洋船载测量空间重力异常数据、卫星测高重力异常,布格重力异常数据、EGM2008地球重力模型数据等多种来源数据的性质和精度,并对相关数据进行对比,研究了编制1∶500万中国海陆空间重力异常图的数据使用方案和技术方法.在地形较为平坦、实测数据分布均匀的陆区,使用实测数据,在地形复杂,实测数据稀少以及没有实测数据的陆区或岛屿,利用布格重力异常反推空间异常的方法合成平均空间重力数据,西藏地区的数据对比实验证明合成平均空间重力异常数据是一种有效的数据补充.利用三观测列方差分解法在南海地区对船载测量空间重力数据和美国SS系列及丹麦DNSC08GRA卫星重力数据进行了方差分解计算,结果表明不同来源的卫星测高重力数据具有很大的一致性,数据精度较以往有了很大的提高.海区空间重力数据使用原则是在船载重力测量数据校准下,全面使用卫星测高重力数据进行编图.海陆过渡区的异常处理应以EGM2008地球重力模型重力场为基准参考场,实现海陆异常平缓过渡,无缝连接.对中国海陆空间重力异常场进行了小波变换处理,对空间重力异常场进行了解读,勾画出三横四竖的一级重力梯级带及其所围限的8个一级重力异常区,并划分了二级重力异常区和梯级带,为块体构造学体系中大地构造格架的建立提供了地球物理证据.
Multi-source gravity data including measurements on land, shipboard surveys, satellite altimetry, Bouguer gravity anomalies and EGM2008 global gravity model data are collected and analyzed for compiling the freei-air gravity anomaly map on the scale of 1 : 5000000 in the land and seas of China and adjacent areas. The data merging and integration method is established based on analysis of the accuracy and resolution of different sources of gravity data. Evenly distributed land gravity data could be gridded in flat land areas. A synthetic method using Bouguer gravity and high precision topographic data to calculate the free-air gravity data is proposed to fill the land areas where the gravity measurement is hardly or impossible to implement due to complex terrain. Data comparison between the synthetic free-air gravity data, measured data and EGM2008 data proves that using the synthetic data is a better choice for filling the areas lacking real data. This method is also applied to the continental and island areas outside China's Mainland where there are no real data collected. The STD analysis method is applied to the northern part of the South China Sea to compare the accuracy of three independent gravity data, the shipboard gravity data and two kinds of satellite altimetry derived gravity data, the SS series from Scripps, US and DNSC08GRA from DTU, Denmark. SS V18. 1 and DNSC08GRA data, which show very good consistence in terms of accuracy and resolution. The standard deviation of the two kinds of satellite gravity data in the SCS is less than 2mGal, which is a major improvement compared with the former SS V16. 1. With the rectification of shipboard gravity data, the wide coverage of satellite gravity data could be used for small-scale free-air gravity mapping. In the coastal zone, the EGM2008 global potential model is used as a reference field providing a seamless gravity transition from land to ocean. Wavelet transform and multiscale analyses are applied to decompose the free-air gravity field in China and its
出处
《地球物理学报》
SCIE
EI
CSCD
北大核心
2014年第12期3920-3931,共12页
Chinese Journal of Geophysics
基金
国土资源地质大调查专项(GZH200900504)(GZH200800503)(200311000007)
全国油气资源战略选取调查与评价国家专项(XQ-2005-01)(2009GYXQ05-1)
国家自然科学基金重大国际(地区)合作研究项目(41210005)
国家自然科学基金青年基金项目(41206050)
科技基础性工作专项(2013FY112900)联合资助
关键词
空间重力异常
海陆联编
卫星测高重力
实测重力
合成空间重力
Free-air gravity anomaly
Conterminous map from land to sea
Satellite altimetry derived gravity
Measured gravity data
Synthetic free-air gravity