Mission Analysis
Mohammad Haji Jafari; Sahar Aminabadi
Abstract
In this paper, we investigate the orbital characteristics of a constellation consisting of 24 LEO satellites. All the configurations are based on the Walker Delta model, which include single- regulated (one constellation) and double- regulated (intertwined two constellations) models. For the sake of ...
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In this paper, we investigate the orbital characteristics of a constellation consisting of 24 LEO satellites. All the configurations are based on the Walker Delta model, which include single- regulated (one constellation) and double- regulated (intertwined two constellations) models. For the sake of comparability, it is assumed that the orbital period of all satellites is 127 minutes and regarding the maximum altitude of 2000 km, the three eccentricities of zero (circle), 0.19 (with an apogee of 2000 km) and 0.097 (=0.19/2) with the longest presence time on the mission area, are considered. In order to limit the search space, the inclination of all orbits is assumed 40 degrees and three values of 320, 340 and 360 degrees are considered for the argument of perigee in elliptical orbits. Examining the various scenarios, it can be seen that, Assuming the need for at least two observable satellites, basically, it can be found that for the argument of perigee of 320 degrees provides the best coverage beside the least standard deviation. As expected, the higher eccentric orbits perform better regardless of changes in signal strength. on the other hand, Double-regulated configurations can be associated with a larger number of satellites in view, which generally is accompanied by higher standard deviations. In General, a configuration may be chosen according to mission requirements and no one should be regarded as the absolute optimum.
