摘要
介绍了能量法恢复地球重力场的基本原理,并分别给出了在笛卡尔坐标空间、极坐标空间内的能量守恒公式,探讨了能量常数精度、计算方式与地球重力场反演精度的关系,并通过数值试验进行了计算分析。计算结果表明:对于低轨卫星,在不同坐标空间内转换引起的轨道误差为10-10m量级,对恢复地球重力场模型的阶误差RMS为10-21量级,可以忽略不计;为了获取厘米级的大地水准面,在解算过程中应该将扰动位期望为零时对应的估值作为能量常数初始估计值,将其残差作为未知数一并求解,且能量常数误差应优于0.1 m2s2。
The principle of inversing earth＇s gravitational model（ EGM） on the basis of energy integral approach is discussed. In order to analyze the relationship between the coordinate spaces with inversion accuracy,we calculate the energy conservation formula in Descartes coordinate and polar coordinate respectively. The results of numerical analysis indicate that the different coordinate spaces introduces only 10^-10m orbit error in low orbital satellite integration and only 10^-21degree error RMS in EGM inversion. In addition, the different ways to calculate energy constant were introduced. The simulation results manifest that the energy constant should be centralized to improve the inversion accuracy,and its precision should better than 0. 1 m^2s^2.
出处
《测绘与空间地理信息》
2014年第5期214-218,共5页
Geomatics & Spatial Information Technology
