利用中国大陆构造环境监测网络中张家口、淮北、溧阳重力台的 gPhone 连续重力观测数据,经过 Tsoft 软件数据预处理、固体潮、海潮负荷、极移等主要潮汐信号的扣除、局部气压改正,以及分段拟合仪器漂移后,得到观测数据的非潮汐信号,该信号时间序列呈现明显的季节性,主要反映陆地水储量变化;在此基础上,将地面重力非潮汐信号的月均值与重力卫星 GRACE 的观测结果进行比较。结果发现,仪器观测较稳定的张家口站和淮北站,地面重力和卫星重力观测的季节性信号具有一定的一致性;而溧阳站两种观测的相关性较差,可能与仪器观测的稳定性及台站周边区域环境因素有关。
The amplitude of regional gravity variation caused by terrestrial water can reach several or even a dozen microgal,which can be monitored by ground-based gravity and by satellite gravity.We select three continuous observation stations using gPhone from the Crustal Movement Observation Network of China and use Tsoft to do original dataset preprocessing. We have removed the gravity effects of major tides:solid earth tide,ocean loading and polar tide,corrected for atmospheric loading effects using local measurements,fitted instrumental drift using segmental fitting.Then we extract non-tidal changes of gravity,which show obvious seasonal changes,mainly reflecting terrestrial water storage changes.Following that we compare the non-tidal signals from monthly mean value of ground-based gravity and GRACE.It is found that,for more stable stations Zhangjiakou and Huaibei,the correlation of ground-based gravity and GRACE are obvious.However,the correlation of the two observations is not clear on Liyang station.This may be associated with the instrumental stability and the regional environmental factors around Liyang station.