摘要
选取滇西重力测网1986~2009年流动重力观测资料及下关、丽江、昆明3个绝对重力基准点多年复测资料作基准控制,采用线性速率模型拟合观测过程中重力场的时变信息,建立绝对重力基准点约束下的动态平差模型,讨论段差观测值及绝对重力基准观测值协方差矩阵的构建、平差模型初值选取及迭代计算等细节问题。经分析,测区内测点的重力年变率范围为（-0.039 5~0.024 1）×10-5 ms-2/a,精度范围为（0.001~0.029 8）×10-5 ms-2/a,与分期静态平差拟合结果的差异约为（0.003~0.020）×10-5 ms-2/a。在处理全国网和较大面积的区域网多年重复观测的重力资料时,尤其是多网多期重力资料联合处理时,应采用动态平差模型来获得统一时间基准和空间基准的重力变化。
In this paper we use the repeated gravity measurements of the western Yunnan gravity net- work with the data length of 1986-2009, as well as absolute gravity observations at Xiaguan, Lijiang, and Kunming gravity sites. Linear gravity rate models are employed to estimate the time variation ge- ophysical information. We build dynamic adjustment models under the constraints of absolute gravity observations, and discuss several key questions including the variance metric for both repeated and ab- solute gravity measurements, the initial values of the models and the iterations ~, robust estimation, and statistic hypothesis testing. We obtain the annual gravity rate at each site in the western Yunnan network with a range of （--0.039 5-0. 024 1）N10 5ms 2/a, and the precision with a range of （0.001- 0.029 8） X10-Sms-2/a, with the difference of （0.003-0.020）X10 ~ms 2/a, as compared with the static adjustment method. When we process the national gravity network or the regional gravity net- work over a relatively large area, especially with multi-network and multi-campaign gravity measure- ments, the dynamic adjustment model developed in this work can ohtain the gravity variation under the united space-time status.
出处
《大地测量与地球动力学》
CSCD
北大核心
2015年第3期508-511,516,共5页
Journal of Geodesy and Geodynamics
基金
中国地震局地震行业专项(201308004
201208009)
国家自然科学基金(41004030
41304059)
中国地震局地震研究所发展基金青年创业基金(IS201026092)
关键词
流动重力观测
动态平差
重力年变率
绝对重力基准
时间基准
repeated gravity measurements
dynamic adjustment
gravity annual rate
absolute gravity status
temporal base
