Design selection of micro-satellites constellation in LEO orbits on purpose of global coverage for communication and AIS services in shipping

Abstract

Last two decades, the trend for microsatellite constellations has been growing, especially in LEO orbits, to support a plethora of applications in various domains. At the same time, the increasing reliability and the use of low-cost (COTS- commercial off-the-shelf) of electronic equipment, in conjunction with the commercialization of space exploration, give an unprecedented momentum to the deployment of mega-constellations. In this ambit, the scope of this dissertation is to identify a design selection of satellite constellation, to support the AIS system for global and specific (Hellenic) region coverage, including the Mediterranean, mainly of commercial vessels. Initially, it has been detected the factors of orbit definition and its characteristics. Then, it is presented a review of satellite constellations, with an emphasis on shipping applications. Steps of design constellation have been identified, to design and simulate the scenarios of eight (8), twelve (12), and twenty-four (24) satellites. Walker-delta method has been used, as the most symmetric and optimum algorithm, for maximum coverage and the minimum number of satellites. Then, with the help of the STK program, simulations of subclasses have been analyzed and the results are related between themselves, to isolate the best performance of the scenarios. The comparison of the results confirmed that the scenario of twenty-four satellites can support the best performance for coverage, from 1350 km and inclination of 45°. At the same time, the scenario of twelve satellites, gives satisfactory results, for both, global and specific regions (Hellenic). Finally, the strategic value of microsatellite constellations, especially for small countries like Greece, has been detected.