Accuracy criterion and analysis of continuous earth observation satellite constellations

A criterion for analyzing the accuracy characteristics of applied satellite constellations (ASC) possible structures for observing targets in the Earth surface and/or near-surface layer is proposed. The criterion is not related to features of onboard hardware and depends on structure, parameters and dynamics of ASC. The criterion is based on consideration of determination accuracy of the objects geographical coordinates. An algorithm for numerical simulation of ASC is presented. Comparative accuracy estimates for various types of ASC are presented. Accuracy characteristics of Walker constellations and Near-Polar Satellite Constellations with various pattern types are considered. The main design-ballistic parameters that determine the accuracy of ASC and affect the cost of their creation are determined, and the nature of these parameters influence also shown. Results can be used for initial decision of ASC pattern during preliminary design stage.