A Small Satellite Constellation for Continuous Coverage of Mid-Low Earth Latitudes

摘要

When located on a geostationary orbit, a satellite keeps a steady position with respect toa generic point on the Earth's surface and this characteristic allows for important advan-tages. A continuous longitudinal coverage of the Earth's surface (higher latitudes excluded)is a result of using a three geo-satellite constellation. Nevertheless, there are also severaldrawbacks related to the geostationary orbit employment. The need to consider alternativesatellite constellations has begun to arise from these disadvantages; these constellations, inspite of having very similar characteristics to the geostationary system, are able to overcomethe complexity, the costs and the launching site problems connected with a geostationarysatellite. For equatorial orbits, the Four-Leaf Clover System represents a profitable alterna-tive compared to the traditional geostationary system. As far as high Earth latitudes are con-cerned, there are different operational constellations, such as Molniya and Tundra, capableof ensuring the continuous coverage of a region and generally taking orbits with a criticalinclination into account (63.43 deg). The aim of this paper is to demonstrate that it is possi-ble to create a satellite constellation capable of ensuring a continuous coverage of mid-lowEarth latitudes. After a general study of the orbits employed to date, followed by a generalgraphical representation, a constellation of eight small satellites in multi-synchronous orbitsmakes the achievement of this paper's aim possible. Several possibilities for application fol-low, both for telecommunications and remote sensing missions.