月球重力场模型球谐函数展开式的核心是一组正常化位系数。介绍了当前几种主要月球重力场模型建立所采用的探测器跟踪数据的特点;分析了重力场信号随模型轨道高度、阶次变化的特性。同时以考拉(Kaula)准则为标准比较了各模型位系数的阶方差曲线与考拉曲线的吻合情况。从信噪比的角度出发,提出了对模型进行可靠性分析的方法。通过计算对比各模型的信噪比来反映其空间频谱信号和频谱误差的强度关系,从而对模型质量和可靠性做出分析评定。
The core of the expansion of gravitational potential into spherical harmonics of Lunar gravity model is a series of normalized potential coefficients. In this paper, the characters of the detector tracking data applied in some main Lunar gravity models were introduced. The changing speciality of the gravity signal along with the orbit height and the order of the model was analyzed. Then taking the Kaula law as criterion, the comparison between the RMS curve of the potential coefficients for the models and the Kaula curve was put up. Considering SNR, a method for model reliability analysis was presented which could estimate the models quality and reliability by comparing the signal-noise ratio of the models that reflected the space frequency spectral signal and errors. The job we have done in this paper is useful in analyzing and estimating on domestic lunar gravity models.