首页|A newly unraveled 13.6-year oscillation from GPS displacements and its potential implications for the dynamic reference frame
A newly unraveled 13.6-year oscillation from GPS displacements and its potential implications for the dynamic reference frame
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
万方数据
Numerous practical geodetic and geophysical applications necessitate precise measurements of GNSS displacements at the millimeter or sub-millimeter level.To attain such precision,it is imperative to identify and analyze the unidentified decadal signals inherent in the GPS displacements.In this research,we employ the optimal sequence estimation method to effectively detect an about 13.6-year oscillational signal with an excited amplitude of 3.6士 1.2 mm in the U-components of the GPS displacements.It is noteworthy that this signal demonstrates a consistent spatial pattern characterized by the spherical harmonic Y2,.2-We conduct a comparative analysis with the 13.6-year oscillation observed in length-of-day variations(and geomagnetic records),finding that they are in reverse phase.After eliminating the Earth's external excitation sources through the utilization of two distinct in-situ hydrological records,we suggest that the 13.6-year GPS signal may come from the internal motions within the Earth.However,the specific excitation source and the detailed physical mechanism remain uncertain.Additionally,we develop a mathematical displacement model to explain the 13.6-year signal.Our findings indicate that this signal can result in displacements of up to 1.37 mm and velocity effects of 0.63 mm/yr(for U-component)at maximum.These results underscore the necessity of incorporating this 13.6-year signal into the construction and maintenance of a dynamic reference frame at the millimeter level.
万方数据
