The use of huber’s method for estimating libration selenographic parameters

Abstract

Currently, cyber-physical systems and technologies are successfully used while implementing space missions and creating coordinate and time reference systems. To solve the problems of spatial orientation and to apply on-board sight cameras and goniometers for this purpose, it is necessary to implement referencing to the visible limb of a celestial body and determine dynamic parameters from the longterm series of observations containing large data array and also erroneous measurements. In this process, the use of robust methods for assessing produced values of the desired parameters plays an important role. This chapter suggests a noise-immune Huber’s method (HuberMestimator method-HMEM) for estimating selenographic and lunar libration parameters. In the investigations, we used positional observations of Mösting A crater concerning the lunar limb. Such observations represent unequal observations depending on the Moon’s optical librations and conditions of observations. Such time series are therefore described by the complex system of conditional equations of desired parameters whose solution by the classic least squares method cannot eliminate erroneous observations from the processing. It is more plausible to estimate long-term observational series using HMEM. As a result, the values of lunar characteristics are obtained with high accuracy of their estimation.