科研之友
微信
新浪微博
Facebook
分享链接
摘要
Earth's oblateness is varying due to the redistribution of Earth's fluid mass and the interaction of various components in the Earth system. Nowadays, continuous Global Positioning System (GPS) observations can estimate Earth's oblateness (J(2)) variations with the least squares method, but are subject to ill-conditioned equations with limited GPS observations and aliasing errors from truncated degrees. In this paper, a Tikhonov regularization method is used to estimate J(2) variations from global continuous GPS observations. Results show that the J(2) has been better estimated from GPS observations based on a Tikhonov regularization method than the usual least squares method when compared to SLR solutions. Furthermore, the amplitudes and phases of the annual and semi-annual J(2) variations are closer to the SLR results with truncated degrees from 2 to 5. Higher truncated degrees will degrade the J(2) estimate. Annual J(2) variations are best estimated from GPS observations with truncated degree 4 and semi-annual J(2) variations are best estimated with truncated degree 2.
- 出版日期2014-9
- 单位中国科学院上海天文台; 中国科学院大学
