Design and evolution of satellite constellations for continuous coverage and mapping of the Earth

Abstract

This study explores the coverage of Earth's regions by satellite constellations, primarily focusing on how different orbital configurations impact observation time across various latitudes. Extreme latitudes, including $66^\circ$, $40^\circ$, $+20^\circ$, $-20^\circ$, and $0^\circ$ are analyzed, revealing that high-latitude areas are observed more frequently by satellites with an inclination of $72^\circ$. One of the objectives of this mission is to make three-dimensional (3D) mapping of regions close to the surface of the Earth, which is necessary in various scientific fields and practical applications. To follow this constraint, at least three satellites are required to be visible at a given time, so the constellations are designed having this point in mind. An increase in the number of satellites per orbital plane led to an improvement in visibility time; however, blind spots still exist, particularly in lower latitudes. To ensure continuous coverage, it was necessary to increase the number of orbital planes, resulting in constellations with up to 40 planes and 18 satellites per plane. Simulations demonstrated that even with 720 satellites, maintaining at least three satellites observing all desired regions is not guaranteed in all configurations. After the designing of the constellation, the time evolution of the satellites are studied, taking into account the flattening of the Earth in the dynamical model, which is a very important force for Low Earth Satellites (LEO).