Yet recent hubble images and ground - based observations find that the positions of the arcs have shifted little in the past 15 years 然而近來從哈伯望遠鏡和地面觀測卻發(fā)現(xiàn),這些圓弧于過去15年來變動不大。
Prior to the 1960s knowledge of the atmosphere above about 30 km was based largely on inferences from ground - based observations 在60年代以前,人們關(guān)于30公里左右以上的高空大氣知識主要是根據(jù)地基觀測推斷得到的。
The temporal , spatial and frequency - field characteristics are discussed . the validity of the corresponding empiric formula is analyzed and the atmospheric effects and correction method are investigated in the data analysis of the ground - based observations . the atmospheric effects on the gravity observations are analyzed and detected using the gravity data recorded with the superconducting gravimeters at the global geodynamic project ( ggp ) stations 利用實測地面氣溫、氣壓資料獲得大氣負荷效應(yīng)時間序列的數(shù)值結(jié)果,研究大氣影響的時間、空間和頻率特征,分析經(jīng)驗公式的有效性,研究地面觀測和數(shù)據(jù)分析大氣影響和改正的方案;利用ggp臺站超導重力觀測資料,分析檢驗大氣重力影響;分析igs臺站大氣位移改正的可能性