Ehsan Mousivand; Sajjad Ghazanfarinia; Yaser Saffar; Masoud Khoshsima
Abstract
Satellite Constellations are the new approach to achieve the capabilities that were previously expected from large and complex satellites. This paper reviews activities and related satellite constellation of about 130 companies and research institutes in the world, with the aim of reviewing the approach ...
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Satellite Constellations are the new approach to achieve the capabilities that were previously expected from large and complex satellites. This paper reviews activities and related satellite constellation of about 130 companies and research institutes in the world, with the aim of reviewing the approach of missions carried out under the name of satellite constellation. Based on the investigations, the main missions performed by these constellations have been with the aim of providing communication services and include 27% of all missions ((Including internet of Things with a 16% and Machine to Machine Services with a 6%) Another important mission is Earth Observation (with 19%), which is carried out with the aim of continuous monitoring and beter management of the earth planet.The most favorite configuration in constellations is based on microsatellites with 42% of all configurations. In this article, by presenting the analysis and results of this studied sample, the tendency towards satellite constellations and the role of Cubesats in this category of space missions have been investigated. The aim of this reseach is to highlight the impact of theses space systems in the space industry and economy by providing 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
In This paper, a domestic regional and independent satellite navigation system, known as "IRANSS" has been designed and analyzed to cover user needs in the Middle East Region. The Space Segment of this constellation is composed of nine satellites in four orbits, in such a way three satellites have been ...
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In This paper, a domestic regional and independent satellite navigation system, known as "IRANSS" has been designed and analyzed to cover user needs in the Middle East Region. The Space Segment of this constellation is composed of nine satellites in four orbits, in such a way three satellites have been considered in one GEO orbit [1] and two satellites are considered in each of three IGSO orbits [2]. Two main Tracking and Control Ground Stations and twenty wide area reference stations, assigned only for augmentation, form the Ground Segment. The focus of this research is on space segment and specially design a navigation constellation and satellites’ system design, and evaluation of the performance of the navigation system in combination with other satellite-based navigation systems, since Augmentation Systems prepare correction signals for a specific Navigation System by ground segment. STK is the main software used to design and analyze the performance of the system by DOP as a reference for Ranging Errors based on Constellation Geometry. All of design parameters are computed in a way to minimize GDOP with four satellites. The parameters of navigation accuracy have been compared with other active GNSS [3] constellations to evaluate error in the designed system. Analysis results express that the geometric accuracy of the designed system is solely 16 meters in 95% of a day in all points of the desired area and would be improved to 14 and 12.5 meters in the case of combination with BeiDou and GPS, respectively
space climate
Omid Shekoofa; Masoud Khoshsima; Sajad Ghazanfarinia; Farhad Bagheroskouei
Abstract
This article discusses the need for research, monitoring and forecasting services related to space weather events and the establishment of a national center to achieve these goals. It starts with an introduction to the growing dependence of human civilization on advanced technologies, including space ...
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This article discusses the need for research, monitoring and forecasting services related to space weather events and the establishment of a national center to achieve these goals. It starts with an introduction to the growing dependence of human civilization on advanced technologies, including space technology, and with an overview of the big investments and costs incurred in building critical infrastructures on Earth and in space. Then, this paper investigates the vulnerability of these infrastructures to space weather events and the need to monitor and predict these phenomena. In the next section, some examples of monitoring and forecasting systems created by different countries and space organizations are introduced. Also, the need to establish a national center in Iran is proposed. The initial organizational structure and mechanism for the activities and cooperation between this center and other national and international institutions are discussed. Finally, different types of actions and the most important activities that can be carried out in this center are presented
dynamics
Hossein Maghsoudi Dehaghani; Amirreza Kosari; Mahdi Fakoor; Masoud Khoshsima
Abstract
Due to the unique characteristics of the geostationary 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 geostationary 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 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
