利用轨道扰动引力谱和大地水准面累计误差谱分析的方法估计未来GRACE(gravity recovery and climate experimenl)Follow—On卫星反演地球重力场的空间分辨率。基于GRACEFollow—On卫星的轨道特性,计算其在高空所受到的径向扰动引力,并根据谱特性及星载加速度计的测量噪声水平分析该卫星能反演重力场的阶数。利用EGM96重力场模型分别计算200km和250km轨道高度处的扰动引力谱。分析其特性表明:在两个轨道高度处分别能反演281阶和242阶的地球重力场模型。给出大地水准面累计误差谱模型,并计算200km和250km轨道高度处大地水准面累计误差谱。分析其谱特性表明:在两个轨道高度处分别能反演至286阶和228阶的地球重力场模型。
The spatial resolution of the earth*s gravity field for the future GRACE Follow-On is discussed by analyzing the spatial disturbance gravity spectrum and the accumulative geoid error spectrum. The radial disturbance gravity with the height 200 km and 250 km is computed, using the EGM96 gravitational field model. Analyzing the radial gravity disturbance spectrum characteristics, a new earth's gravity field model of 281 and 242 degrees can be recovered at the two orbit heights. The accumulative geoid error spectrum model is given, and the accumulative geoid error spectrum at the height of 200km and 250km is computed. Analyzing the accumulative geoid error, it can be concluded that the earth's gravity field can be recovered to a degree of 286 and 228.