Ehsan Mousivand; Sajjad Ghazanfarinia; Yaser Saffar; Masoud Khoshsima
Abstract
Satellite Constellations are the new approach to achieve the applications that were presumably expected from large and complex satellites. This paper reviews activities and related satellite constellation of about 130 companies and research institutes, showing that Communication Missions (Internet of ...
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Satellite Constellations are the new approach to achieve the applications that were presumably expected from large and complex satellites. This paper reviews activities and related satellite constellation of about 130 companies and research institutes, showing that Communication Missions (Internet of Things and Machine to Machine Services) are the most desirable for Constellations with 27% of all. Earth Observation constellations are in the next rank with 19%. The most favorite configuration in Constellations is based on Microsatellites with 42%, out of which Cubesats are of more interest. The research is going to present the role of Cubesats with some statistical analysis to show how these Space Systems may affect the future of Space Industry and Economy with Solutions based on Constellations. Results discuss the Future of Constellations and Cubesats and their common effect on New Space both in Space Industry Level and Space Economy. This review may help researchers to work on similar studies with business approaches, too.
mechanic
Sajjad Ghazanfarinia; Ehsan Mousivand; Masoud Khoshsima; Yaser Saffar
Abstract
This research is going to present design of a LEO Constellation for Navigation service with minimum number of Satellites. The goal is to achieve Dilution Of Precision (DOP) less than 6. This Requirement is going to be achieved using predefined launch vehicles limitation on orbit which is 500 km in circular ...
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This research is going to present design of a LEO Constellation for Navigation service with minimum number of Satellites. The goal is to achieve Dilution Of Precision (DOP) less than 6. This Requirement is going to be achieved using predefined launch vehicles limitation on orbit which is 500 km in circular orbit altitude and 55 degrees for orbit inclination. Design has been done based on Analyses resulting in Optimization for least number of Satellites in this orbit, to satisfy all requirements for Navigation Performance and in conformance with the constraints related to launch and orbit. Multiple analyses have been done resulted in Constellation with 324 satellites, formed in 18 Orbits with 18 Satellites in each. This design shows the performance of 4.7 in DOP for a User located in Tehran, however, the distribution of DOP over the target area shows that the requirement has been passed through the whole region.
Mission design
Yaser Saffar; Sajjad Ghazanfarinia; Masoud Khoshsima; Shiva Emami
Abstract
This paper reviews design of Constellation for independent satellite-based navigation system with Middle East region coverage for regional positioning and augmentation service. Space segment of this constellation is composed of nine satellites in four orbits in such way three satellites have been placed ...
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This paper reviews design of Constellation for independent satellite-based navigation system with Middle East region coverage for regional positioning and augmentation service. Space segment of this constellation is composed of nine satellites in four orbits in such way three satellites have been placed on one GEO and two satellites on each three IGSO. In the coverage area, ground segment includes eleven ground monitoring stations, two masters and tracking control stations and twenty wide area reference stations are assigned only for augmentation with their master and uplink stations. Here we centered on space segment and specially design a navigation constellation system as a main orientation in this investigation and evaluation of the performance of the navigation system by combination with other satellite-based navigation systems. Hence, the parameters corresponding to navigation accuracy have been analyzed and compared with other active GNSS constellations. Analyses results express that geometric accuracy (GACC) of the designed system is solely 16 meters in 95% of a day in all points of desired area and in the case of combination with BeiDou and GPS the GACC would be improved to 14 and 12.5 meters respectively.
dynamics
Hossein Maghsoudi Dehaghani; Amirreza Kosari; Mahdi Fakoor; Masoud Khoshsima
Abstract
Due to the unique characteristics of the geo-synchronous orbit and the importance of establishing a satellite in this flying corridor, it is necessary to investigate the effect of environmental disturbances on the orbital elements and to maintain the satellite orbital elements in order to increase the ...
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Due to the unique characteristics of the geo-synchronous orbit and the importance of establishing a satellite in this flying corridor, it is necessary to investigate the effect of environmental disturbances on the orbital elements and to maintain the satellite orbital elements in order to increase the longevity and operation of a satellite in this orbit. A satellite in earth orbit is also always exposed to various environmental disturbances such as earth gravity gradient force, gravity of the moon and sun, solar radiation pressure, and so on. For this reason, it is constantly deviating from its original path and needs to study the effect of environmental disturbances on the orbital elements in order to properly correct the disturbed orbital parameters. To achieve the above goals, in this paper, we try to investigate the effect of the environmental perturbations on the orbital characteristics by simulating the satellite translational dynamic behavior in the presence of environmental disturbances. Then, utilizing the genetic algorithm and fuzzy logic approach, an attempt was made to modify the compensation logic of the orbital elements correction, so that, the satellite may be forced to remain in its limited operational orbital window during the mission lifetime. The proposed method could improve the problem-solving operational effectiveness to maintain the position of the satellite with the criterion of minimizing fuel consumption. The case study simulation results may indicate the capability of the proposed approach in satisfying the performance requirements of the satellite station-keeping maneuver.
