重力异常阶方差模型的构建及在扰动场元频谱特征计算中的应用

摘要

The analysis of Tscherning,Jekeli and Rapp gravity anomaly degree variance model is made according to the new gravity field model-EGM2008,the results show that the traditional gravity anomaly degree variance model can＇t exactly describe the spectral sensitivity of disturbing gravity functions.A new degree variance model-TSD model is presented under two spectral sector by using the non-linear least-square regression method,the standard deviations and mean value of results compared with EGM2008 are respectively 0.25×（10-5 m/s2）2,0.00×（10-5 m/s2）2.The spectral sensitivity of geoid undulation,gravity anomaly,disturbing gravity,deflection of vertical are computed by using the TSD model.The results show that the spectral sensitivity of gravity anomaly,disturbing gravity and vertical deflections increase largely in medium and low spectra.At the same time,the ratios of both three disturbing gravity functions in high spectra decrease largely.%利用最新的全球引力位模型-EGM2008对经典的Tscherning、Jekeli、Rapp 3种重力异常阶方差模型进行分析比较。结果表明,3种经典的阶方差模型已经不能准确地描述扰动场元在各个频段的频谱分布。利用非线性最小二乘回归方法在EGM2008位模型获得的阶方差数据基础上构建新的分段重力异常阶方差模型——TSD模型,该模型与EGM2008位模型计算的阶方差比较其标准差和均值分别为0.25×（10-5 m/s2）2、0.00×（10-5 m/s2）2。利用TSD模型计算不同频段内大地水准面高、重力异常、扰动重力、垂线偏差4个重力场扰动场元的频谱特征。计算结果表明：扰动场元频谱分布较之传统分析结果有较大的变化,其中重力异常、扰动重力及垂线偏差在中、低频部分的能量有明显的增加而高频及甚高频部分的比重有明显的减少。