Abstract
Accessibility gaps are inherent properties of Low Earth Orbit (LEO) sun-synchronous satellite missions. Long accessibility gaps in satellite missions imply strict in-orbit autonomy requirement, met by expensive solutions. Thus, methods to shorten accessibility gaps in satellite missions are appreciated by space mission designers. For that purpose, in this paper, ground segment site location is employed as a mechanism to reduce the longest accessibility gaps in LEO sun-synchronous missions. For a given repeatability cycle, it is shown that longitude of the ground segment does not affect the access gaps. Simulation results show that increasing the latitude of ground segment reduces the longest accessibility gaps, especially in extreme latitudes near Polar Regions. To avoid polar ground segments due to their practical difficulties, mission architectures with two co-high-latitude ground segments are proposed. Selection of longitude distance between the two co-high-latitude ground segments is discussed to further reduce the longest accessibility gap in LEO sun-synchronous missions. To show the feasibility of the proposed approach, simulation results are included for illustration.
Keywords:
Ground segment location; LEO sun-synchronous satellite; Longest accessibility gap
Full text is available only in PDF.
REFERENCES
- Anilkumar, A.K., Sudheer Reddy, D., 2009, "Statistical Conjunction Analysis and Modeling of Low-Earth-Orbit Catalogued Objects", Journal of Spacecraft and Rockets, Vol. 46, No. 1, pp. 160-167. doi: 10.2514/1.36976.
» https://doi.org/10.2514/1.36976 - Bonyan Khamseh, H., Navabi, M., 2010a, "Development of Metrics for Ground Segment Site Location Based on Satellite Accessibility Pattern from Ground Segment", Proceedings of the 4th Asia-Pacific Conference on Systems Engineering, Keelung, Taiwan.
- Bonyan Khamseh, H., Navabi, M., 2010b, "Development of Access-based Metrics for Site Location of Ground Segment in LEO Missions", Journal of Aerospace Technology and Management, Vol. 2, No. 3, pp. 279-286. doi: 10.5028/jatm.2010.02038210.
» https://doi.org/10.5028/jatm.2010.02038210 - Capderou, M., 2005, "Satellites Orbits and Missions", Springer-Verlag, Berlin, Germany, 364 p.
- Chester, E., 2009, "Down to Earth systems engineering: The forgotten ground segment", Acta Astronautica, Vol. 65, No 1-2, pp. 206-213.
- Dittberner, G., McKnight, D., 1993, "Collision Risk in Sunsynchronous Low Earth Orbit", Advances in Space Research, Vol. 13, No. 8, pp. 187-190. doi: 10.1016/0273-1177(93)90589-4.
» https://doi.org/10.1016/0273-1177(93)90589-4 - Li, S.Y., Liu, C.H., 2002, "An analytical model to predict the probability density function of elevation angles for LEO satellites", IEEE Communications Letters, Vol. 6, No. 4, pp. 138-140.
- Modiri, A., Mohammady, L., 2008, "Mathematical Prediction of Sun-synchronous Polar LEO Satellite Visions for Earth Stations", Proceedings of 10th International Conference on Advanced Communication Technology, Korea, pp. 1559-1563.
- Petersen, J.L., 1994, "The Road to 2015: Profiles of the Future", Waite Group Press, Corte Madera, CA, USA.
- Sandau, R., 2010, "Status and Trends of Small Satellite Missions for Earth Observation", Acta Astronautica, Vol. 66, No. 1-2, pp. 1-12.
- Stephens, J.P., 2002, "A Novel International Partnership: The Disaster Monitoring Constellation of Small Low Cost Satellites", Proceedings of the United Nations Regional Workshop on the Use of Space Technology for Disaster Management in Asia and the Pacific, Bangkok, Thailand.
- Wertz, J.R., Larson, W.J., 1999, "Space Mission Analysis and Design", 3rd Ed., Microcosm Press, Bloomington, IN, USA, 969 p.
Publication Dates
-
Publication in this collection
Jan-Apr 2011
History
-
Received
10 Feb 2011 -
Accepted
05 Mar 2011
