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Journal articles on the topic 'Satellite system'
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1
Saiko, Volodymyr, Teodor Narytnyk, Valeriy Gladkykh, and Natalia Sivkova. "INNOVATIVE SOLUTION FOR LEO-SYSTEM WITH DISTRIBUTED SATELLITE ARCHITECTURE." Information systems and technologies security, no. 1 (2) (2020): 77–83. http://dx.doi.org/10.17721/ists.2020.1.77-83.
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An innovative solution for practical implementation in a LEO system with a "distributed satellite" architecture that can be used to provide low-orbital spacecraft communications with ground stations and users of 5G / IoT satellite services is proposed. The essence of the proposed development in the system of low-orbital satellite communication with FC-architecture is that to reduce the delay in signaling to consumers and the probability of overloading the network into a prospective system of low-orbital satellite communication, which contains artificial Earth satellites, each of which functions in Earth orbit and equipped with onboard repeaters, inter-satellite communications, a network of ground-based communication and control systems for artificial satellites of the Earth, a grouping of low-orbiting space their devices (LEO-system), which includes the grouping of root (leading) satellites and satellites-repeaters (slave), around each root satellite is formed micro-grouping of satellites-repeaters, and functions of the root satellite in the selected orbital phase of the orbital -or micro-satellites that are connected to the annular network by communication lines between satellites, and - functions of satellites-repeaters - kubsat, new is the introduction of a multilevel boundary cloud system, which is a heterogeneity distributed computing cloud structure. At the same time, the boundary clouds of the multilevel system are connected by ultra-high-speed wireless terahertz radio lines and wireless optical communication systems. The technique of estimation of access time in the proposed structure of "fog computing" on the basis of the model of access in "fog computing" with the resolution of collisions of data sources implementing the survey mode is presented.
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Utami, Vi Bauty Riska, Imam MPB, and Shinta Romadhona. "Analysis the impact of sun outage and satellite orbit at performance of the telkom 3S satellite communication system." JURNAL INFOTEL 13, no. 3 (August 31, 2021): 134–42. http://dx.doi.org/10.20895/infotel.v13i3.626.
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Satellites of communication are located at altitude of thousands kilometers above the earth's surface, so the signal is transmitted by satellite to earth station is very susceptible to interference. Every March and September equinox or when the sun crosses the Earth's equator for several days, earth station occurs a naturally interference called by sun outage. At this time, satellite and the sun reach the closest distance because satellite's position is same direction with the sun. This interference makes the signal received by earth station weaken and even disappears due to temperature noise which increases drastically. Loss of signal on the downlink side caused by noise greatly affects to the performance of satellite communication system. This study aims to analyze the effect of sun outage and satellite orbit to determine sun outage period on the performance of Telkom 3S satellite communication system. The results obtained that indicate the signal quality is represented by degradation in the Carrier to Noise Ratio (C/N) from 14,777 dB to 6,0 dB, Energy bits per Noise Ratio (Eb/No) from 11,515 dB to 2,738 dB, and increase the Bit Error Rate (BER) from 8,29×10-7 to 11,08×10-3. In addition, sun outage makes lost of satellite communication traffic and affecting link availability to 99,855324%. Meanwhile, the result from satellite orbit calculation for sun outage period based on ITU-R S.1525 standard and based by satellite’s handbook.
Keywords – Telkom 3S satellite, sun outage, C/N, Eb/No, BER, link availability, sun outage period.
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Zheng, Jun Hua, and Chang Ju Wu. "Design of Moving System for Pico-Satellite Deployer." Applied Mechanics and Materials 325-326 (June 2013): 1009–13. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.1009.
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Pico-satellite’s potential use is increasingly gaining nation’s recognition. Because of its small volume and light weight, it is necessary to develop the special deployer. The key technologies of Zhejiang University Pico-Satellite Deployer (ZDPSD) are, cutter unlocking the door, conical spring driving the pico-satellite, oriented rail restricting the direction and locking shaft fixing the door. In September 2010, the two pico-satellites were launched and deployed successfully at the predetermined orbit. The paper includes designing and analyzing of the moving system, mode analyzing of the deployer and the experiments on ground and in-orbit. The key process of the development is summarized, which can be regarded as reference for the further developing.
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Klaes, K. Dieter, Marc Cohen, Yves Buhler, Peter Schlüssel, Rosemary Munro, Juha-Pekka Luntama, Axel von Engeln, et al. "An Introduction to the EUMETSAT Polar system." Bulletin of the American Meteorological Society 88, no. 7 (July 1, 2007): 1085–96. http://dx.doi.org/10.1175/bams-88-7-1085.
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The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Polar System is the European contribution to the European–U.S. operational polar meteorological satellite system (Initial Joint Polar System). It serves the midmorning (a.m.) orbit 0930 Local Solar Time (LST) descending node. The EUMETSAT satellites of this new polar system are the Meteorological Operational Satellite (Metop) satellites, jointly developed with ESA. Three Metop satellites are foreseen for at least 14 years of operation from 2006 onward and will support operational meteorology and climate monitoring. The Metop Programme includes the development of some instruments, such as the Global Ozone Monitoring Experiment, Advanced Scatterometer, and the Global Navigation Satellite System (GNSS) Receiver for Atmospheric Sounding, which are advanced instruments of recent successful research missions. Core components of the Metop payload, common with the payload on the U.S. satellites, are the Advanced Very High Resolution Radiometer and the Advanced Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder (ATOVS) package, composed of the High Resolution Infrared Radiation Sounder (HIRS), Advanced Microwave Sounding Unit A (AMSU-A), and Microwave Humidity Sounder (MHS). They provide continuity to the NOAA-K, -L, -M satellite series (in orbit known as NOAA-15, -16 and -17). MHS is a EUMETSAT development and replaces the AMSU-B instrument in the ATOVS suite. The Infrared Atmospheric Sounding Interferometer (IASI) instrument, developed by the Centre National d'Etudes Spatiales, provides hyperspectral resolution infrared sounding capabilities and represents new technology in operational satellite remote sensing.
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Sochacki, Mateusz, and Janusz Narkiewicz. "Propulsion System Modelling for Multi-Satellite Missions Performed by Nanosatellites." Transactions on Aerospace Research 2018, no. 4 (December 1, 2018): 58–67. http://dx.doi.org/10.2478/tar-2018-0030.
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Abstract Progress in miniaturization of satellite components allows complex missions to be performed by small spacecraft. Growing interest in the small satellite sector has led to development of standards such as CubeSat, contributing to lower costs of satellite development and increasing their service competitiveness. Small satellites are seen now as a prospective replacement for conventional sized satellites in the future, providing also services for demanding users. New paradigms of multi-satellite missions such as fractionation and federalization also open up new prospects for applications of small platforms. To perform a comprehensive simulation and analysis of future nanosatellite missions, an adequate propulsion system model must be used. Such model should account for propulsion solutions which can be implemented on nanosatellites and used in multi-satellite missions. In the paper, concepts of distributed satellite systems (constellations, formations, fractionated and federated) are described with a survey of past, on-going and planned multi-satellite nanosatellites missions. Currently developed propulsion systems are discussed and the models of propulsion systems embedded in the WUT satellite simulation model are presented.
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Machida, Kazuo, and Toshiaki Iwata. "Development of Space Environment Preservation System Using Robot." Journal of Robotics and Mechatronics 18, no. 1 (February 20, 2006): 67–75. http://dx.doi.org/10.20965/jrm.2006.p0067.
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We propose the concept of a robot-oriented space system called the “Space Environment Preservation System” that maintains a satellite constellation and orbit, and develop the basic technologies. A space maintenance vehicle carries and assembles modularized satellites, and places them in orbit. It captures and diagnoses them and replaces malfunctioning modules, to increase the reliability and life of the satellite constellation. It also collects, disassembles and removes satellites from orbit at the end of a mission, helping to preserve the space environment. In order to realize the system, the modularized satellite that can be easily assembled, maintained and disassembled by a robot must be devised. We developed the ground model of such a satellite, as well as the multifunctional space maintenance vehicle that functions as an in-orbit satellite assembly plant, diagnostic station, and satellite captor. These functions were demonstrated on a space simulated testbed.
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Papiya, Sumaiya Janefar, Dr Bobby Barua, and Mehnaz Hossain. "Prospects Challenges of Bangabandhu Satellite-2." International Journal of Advanced Networking and Applications 14, no. 02 (2022): 5342–52. http://dx.doi.org/10.35444/ijana.2022.14204.
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The development of the Bangabandhu Satellite-1 has changed the direction of Bangladesh's satellite communication research. Bangladesh's dream project was the Bangabandhu Satellite 1. This satellite's primary goal is to maintain effective internet and communication services in remote places. First of all, we must concentrate to the depth of satellite communication system and its process to reach any conclusion. Our main goal of the research is to recognize a feasibility review on Bangabandhu satellite-2. So, for the feasibility studies we reviewed the most promising technical parts of Bangabandhu satellite-1. Here, we only focused the certain parts of the satellite such as coding, modulation, battery, purpose of ground station and the benefits of the satellite communication system. Then we moved on the main parts of the Bangabandhu satellite-2. As, Bangabandhu satellite-1 was Geosynchronous equatorial orbit (GEO) communication satellite and Bangabandhu satellite-2 will be Low Earth Orbit (LEO) observation satellite (LEO) so, some of configurations between them might be changed. Furthermore, we largely focused on Facts, efficiency, performance and noticeable difference between two satellites.
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Ильченко, Михаил Ефимович, Теодор Николаевич Нарытник, Борис Михайлович Рассамакин, Владимир Ильич Присяжный, and Сергей Владимирович Капштык. "СОЗДАНИЕ АРХИТЕКТУРЫ «РАСПРЕДЕЛЕННОГО СПУТНИКА» ДЛЯ НИЗКООРБИТАЛЬНЫХ ИНФОРМАЦИОННО-ТЕЛЕКОММУНИКАЦИОННЫХ СИСТЕМ НА ОСНОВЕ ГРУППИРОВКИ МИКРО- И НАНОСПУТНИКОВ." Aerospace technic and technology, no. 2 (April 26, 2018): 33–43. http://dx.doi.org/10.32620/aktt.2018.2.05.
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Presented are the results of an analysis of the growing interest in the use of low Earth orbits (up to 1500 km high) for the introduction and development of the Internet of things (Internet of Things - IoT). Industrial Internet of things (Industrial Internet of Things-IIoT). Internet of things for remote areas (Remote Internet of Things - RioT, for the purposes of scientific research and economic use of natural resources, control of the development and operation of infrastructure projects, the operation of territorially distributed industrial production, transport infrastructure. Factors significantly limiting the further introduction of micro and nano satellites are given. The authors proposed to resolve this contradiction on the basis of the developed concept of creating the architecture of a "distributed satellite". As an example, the article considers possible applications of the distributed satellite architecture in two segments of the space information systems market: remote sensing of the Earth and telecommunication systems. The application of the "distributed satellite" in radar systems with synthesized aperture (SAR-system) was considered taking into account the requirements of the operators of satellite SAR-systems and consumers of their information. It is shown. that the use of the "distributed satellite" architecture in SAR-systems also makes it possible to realize the technology of multi-static radar with a "soft" interference base (from 200 m to 1 km). The scheme of organization and interaction of the "distributed satellite" in the satellite-transmitter on the platform of the micro satellite, which is the core of the satellite cluster, and several satellites-receivers on the cube-sat platform is presented. The functions performed by the satellite-transmitter, the inter-satellite radio link and the satellite-receiver are considered in detail. The work of the "distributed satellite" is illustrated by the presented structural diagram of the SAR-system for remote sensing of the Earth, a version of the architecture of the low-orbit satellite communication system and the scheme for constructing a satellite system for the provision of IoT services. In conclusion, it is noted that the architecture of the "distributed satellite" makes it possible to effectively use satellites of the class of micro/nano satellite (cube-sat) to create complex space-based information and telecommunication systems
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Loh, Robert. "GPS Wide Area Augmentation System (WAAS)." Journal of Navigation 48, no. 2 (May 1995): 180–91. http://dx.doi.org/10.1017/s0373463300012649.
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Today, no single technology has more broad-reaching potential for worldwide civil aviation than the future applications of satellite technology. These applications represent the greatest opportunity to enhance aviation system capacity, efficiency and safety since the introduction of radio-based navigation systems more than 50 years ago. The foundation for this optimism is the Global Positioning System (GPS), a satellite-based radio navigation system operated and controlled by the United States Department of Defense (DoD). In December 1993, DoD declared GPS to be in initial operational capability (10c), which means 24 satellites are now in orbit, available and usable for satellite navigation. The Federal Aviation Agency (FAA) responded to this potential through initiation of a comprehensive satellite programme involving government, industry and users to expedite research, development and field implementation of satellite-based navigation services.
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Midthassel, Rolv, and Harald Ernst. "A mobile multimedia satellite system reusing existing satellites." International Journal of Satellite Communications and Networking 26, no. 5 (September 2008): 445–61. http://dx.doi.org/10.1002/sat.904.
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Chauhan, Mayur, Teesha Sonawane, Yash Mehta, and Mahalaxmi Palinje. "Review on Automatic Antenna Tracking System For LEO Satellites." International Journal for Research in Applied Science and Engineering Technology 11, no. 1 (January 31, 2023): 188–93. http://dx.doi.org/10.22214/ijraset.2023.48515.
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Abstract: This paper is about comparing the Yagi- Uda Antenna, Turnstile Antenna, Parabolic Antenna Phased Array Antenna with a different parameters required to track LEO Satellites and to receive the Telemetry Information from them. LEO Satellites is Low Earth Orbit typically organized as a satellite constellation. The number of Satellite LEO would be ten to even thousand to fully cover the globe. As LEO satellites move very quickly and are most visible for 20to 30 min during each pass, it requires an antenna that can track signals, and satellite paths, and upload anddownload as much data as possible in a short amount of time. The continual motion of tracing one LEO satellite after other equates to significant mechanical performance. So in this paper, we carry out a review of which antenna suites are best for tracking the LEO, getting data from them, and also the mechanical parameter of Antennas.
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Gong, Chang Qing, Zhen Chun Jiang, Chao Hui Huang, Ping Wang, and Tong Wu. "Optimization Analysis of GDOP of PL-Aided Navigation and Positioning System." Applied Mechanics and Materials 239-240 (December 2012): 544–47. http://dx.doi.org/10.4028/www.scientific.net/amm.239-240.544.
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The precision of satellite positioning system depends largely on the numbers and geometric layout of the positioning satellite, the GDOP is one of the important parameters to measure the geometric layout of positioning satellites. From the perspective of GDOP, the relation between a different pseudo-satellite location and layout for the accuracy of the positioning system has been studied. For the positioning of the four pseudo-satellites, the simulation analysis of the relationship of the GDOP parameter changes with the pseudo-satellite longitude, latitude and location of the user. Studies have shown that different latitudes, the symmetrical distribution of the pseudo-satellite layout has good geometric accuracy; the same layout, the low-latitude, GDOP is less than the high-latitude; when the user moves in the regional variation in the geometric center of the pseudo-satellite layout, the GDOP values did not change and less than the value of the central region; at the same time, increasing the number of pseudo-satellite can reduce the GDOP value.
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Zhao, Xiangyu, Chunjuan Zhao, Jiale Li, Yongliang Guan, Shanbo Chen, and Lei Zhang. "Research on Design, Simulation, and Experiment of Separation Mechanism for Micro-Nano Satellites." Applied Sciences 12, no. 12 (June 13, 2022): 5997. http://dx.doi.org/10.3390/app12125997.
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The separation mechanism is a critical device that transports and releases satellites during launch and on-orbit. However, as satellites become smaller and more compact, the traditional belt-locking device or pyrotechnic release and separation device cannot meet the micro-nano satellite’s separation requirements. A novel separation mechanism kinematic system was designed, analyzed, and experimentally verified to achieve non-interference and non-pyrotechnic separation of the satellites from the launch vehicle while maintaining the initial separation attitude. First, an overall structural strategy for the kinematics system was proposed based on the MF (product code of the satellite) satellite’s structural properties. The structural characteristics of the separation mechanism were also confirmed by the principle of energy conservation. Then, a finite element model and a dynamic model of the kinematic coupling system between the MF satellite and the separation mechanism during launch and deployment were constructed, along with an analysis of the mechanical characteristics and a kinematic simulation. Finally, the mechanical characteristics and dependability of the separation mechanism were verified using a ground vibration test and a separation test. The prototype test results demonstrate that the separation process is essentially identical to the numerical simulation results and that the MF satellite can be deployed successfully without interference, with the MF satellite’s initial separation attitude fully satisfying the designed technical indexes.
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Xian, Di, Peng Zhang, Ling Gao, Ruijing Sun, Haizhen Zhang, and Xu Jia. "Fengyun Meteorological Satellite Products for Earth System Science Applications." Advances in Atmospheric Sciences 38, no. 8 (April 27, 2021): 1267–84. http://dx.doi.org/10.1007/s00376-021-0425-3.
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AbstractFollowing the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerical weather prediction models and earth system models, meteorological satellites will play a more important role in earth sciences in the future. As part of the space-based infrastructure, the Fengyun (FY) meteorological satellites have contributed to earth science sustainability studies through an open data policy and stable data quality since the first launch of the FY-1A satellite in 1988. The capability of earth system monitoring was greatly enhanced after the second-generation polar orbiting FY-3 satellites and geostationary orbiting FY-4 satellites were developed. Meanwhile, the quality of the products generated from the FY-3 and FY-4 satellites is comparable to the well-known MODIS products. FY satellite data has been utilized broadly in weather forecasting, climate and climate change investigations, environmental disaster monitoring, etc. This article reviews the instruments mounted on the FY satellites. Sensor-dependent level 1 products (radiance data) and inversion algorithm-dependent level 2 products (geophysical parameters) are introduced. As an example, some typical geophysical parameters, such as wildfires, lightning, vegetation indices, aerosol products, soil moisture, and precipitation estimation have been demonstrated and validated by in-situ observations and other well-known satellite products. To help users access the FY products, a set of data sharing systems has been developed and operated. The newly developed data sharing system based on cloud technology has been illustrated to improve the efficiency of data delivery.
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Cui, Jun Xia, and Hu Li Shi. "A Novel Satellite Telephone Communication System Based on SIGSO Satellite." Applied Mechanics and Materials 446-447 (November 2013): 1642–46. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.1642.
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In recent years, the coverage of terrestrial mobile communication network is more and more extensive, and the mobile phones have occupied the vast majority of voice communications in almost all countries. However, satellite voice communication system is still playing an irreplaceable role on the vast sea and the land area which are not covered by the land mobile communication network. The motion characteristics of the SIGSO satellites and its new demands and characteristics to the system are analyzed, and a novel very low rate satellite telephone system is put forward. The speech coding algorithms are studied, and a suitable speech coding algorithm and coding rate of 600bps is selected for the SIGSO satellite communication system. The overall design of the satellite voice communication network is given, including link budgets, network structure, system components, system signaling and so on. This satellite telephone system can get access to the PSTN network through ground gateway to achieve interoperability with the public network.
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Tong, Minglei, Song Li, Xiaoxiang Wang, and Peng Wei. "Inter-Satellite Cooperative Offloading Decision and Resource Allocation in Mobile Edge Computing-Enabled Satellite–Terrestrial Networks." Sensors 23, no. 2 (January 6, 2023): 668. http://dx.doi.org/10.3390/s23020668.
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Mobile edge computing (MEC)-enabled satellite–terrestrial networks (STNs) can provide task computing services for Internet of Things (IoT) devices. However, since some applications’ tasks require huge amounts of computing resources, sometimes the computing resources of a local satellite’s MEC server are insufficient, but the computing resources of neighboring satellites’ MEC servers are redundant. Therefore, we investigated inter-satellite cooperation in MEC-enabled STNs. First, we designed a system model of the MEC-enabled STN architecture, where the local satellite and the neighboring satellites assist IoT devices in computing tasks through inter-satellite cooperation. The local satellite migrates some tasks to the neighboring satellites to utilize their idle resources. Next, the task completion delay minimization problem for all IoT devices is formulated and decomposed. Then, we propose an inter-satellite cooperative joint offloading decision and resource allocation optimization scheme, which consists of a task offloading decision algorithm based on the Grey Wolf Optimizer (GWO) algorithm and a computing resource allocation algorithm based on the Lagrange multiplier method. The optimal solution is obtained by continuous iterations. Finally, simulation results demonstrate that the proposed scheme achieves relatively better performance than other baseline schemes.
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Xuan, Cheng, Li ZhiGang, Yang XuHai, Wu WenJun, Lei Hui, and Feng ChuGang. "Chinese Area Positioning System With Wide Area Augmentation." Journal of Navigation 65, no. 2 (March 12, 2012): 339–49. http://dx.doi.org/10.1017/s0373463311000750.
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The Chinese Area Positioning System (CAPS) is a regional satellite navigation system; its space segment consists of some Geostationary Earth Orbit (GEO) satellites and 2∼3 Inclined Geo-Synchronous Orbit (IGSO) satellites. Only a few satellites are needed to provide good area coverage and hence it is an ideal space segment for a regional navigation system. A time transfer mode is used to transmit navigation signals, so no high-precision atomic clocks are required onboard the satellites; all of the transferred navigation signals are generated by the same atomic clock at the master control station on the ground. By using virtual clock technology, the time of emission of signals from the ground control station is transformed to the time of transfer of signals at the phase centre of the satellite antenna; thus the impact of ephemeris errors of satellite on positioning accuracy is greatly decreased, enabling the CAPS to have the capability of wide area augmentation. A novel technology of orbit determination, called Paired Observation Combination for Both Stations (POCBS), proposed by the National Time Service Centre, is used in CAPS. The generation and measurement of ranging signals for the orbit survey are carried out in the ground station and the instrument errors are corrected in real-time. The determination of the clock offset is completely independent of the determination of satellite orbit, so the error of the clock offset has no impact on orbit determination. Therefore, a very high precision of satellite orbits, better than 4·2 cm (1 drms) can be obtained by the stations under regional distribution.
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Wu, Shiyu, Dongkai Yang, Yunlong Zhu, and Feng Wang. "Improved GNSS-Based Bistatic SAR Using Multi-Satellites Fusion: Analysis and Experimental Demonstration." Sensors 20, no. 24 (December 11, 2020): 7119. http://dx.doi.org/10.3390/s20247119.
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The Global Navigation Satellite System (GNSS)-based Bistatic Synthetic Aperture Radar (SAR) is getting more and more attention in remote sensing for its all-weather and real-time global observation capability. Its low range resolution results from the narrow signal bandwidth limits in its development. The configuration difference caused by the illumination angle and movement direction of the different satellites makes it possible to improve resolution by multi-satellite fusion. However, this also introduces new problems with the resolution-enhancing efficiency and increased computation brought about by the fusion. In this paper, we aim at effectively improving the resolution of the multi-satellite fusion system. To this purpose, firstly, the Point Spread Function (PSF) of the multi-satellite fusion system is analyzed, and focusing on the relationship between the fusion resolution and the geometric configuration and the number of satellites. Numerical simulation results show that, compared with multi-satellite fusion, dual-satellite fusion is a combination with higher resolution enhancement efficiency. Secondly, a method for dual-satellite fusion imaging based on optimized satellite selection is proposed. With the greedy algorithm, the selection is divided into two steps: in the first step, according to geometry configuration, the single-satellite with the optimal 2-D resolution is selected as the reference satellite; in the second step, the angles between the azimuthal vector of the reference satellite and the azimuthal vector of the other satellites were calculated by the traversal method, the satellite corresponding to the intersection angle which is closest to 90° is selected as the auxiliary satellite. The fused image was obtained by non-coherent addition of the images generated by the reference satellite and the auxiliary satellite, respectively. Finally, the GPS L1 real orbit multi-target simulation and experimental validation were conducted, respectively. The simulation results show that the 2-D resolution of the images produced by our proposed method is globally optimal 15 times and suboptimal 8 times out of 24 data sets. The experimental results show that the 2-D resolution of our proposed method is optimal in the scene, and the area of the resolution unit is reduced by 70.1% compared to the single-satellite’s images. In the experiment, there are three navigation satellites for imaging, the time taken to the proposed method was 66.6% that of the traversal method. Simulations and experiments fully demonstrate the feasibility of the method.
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Zhang, Pengfei. "Research on satellite selection algorithm in ship positioning based on both geometry and geometric dilution of precision contribution." International Journal of Advanced Robotic Systems 16, no. 1 (January 1, 2019): 172988141983024. http://dx.doi.org/10.1177/1729881419830246.
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With the networking of four Global Navigation Satellite Systems, the combination of multi-constellation applications has become an inevitable trend, and there will be more and more visible satellites that can be participated in ship positioning. However, the computational complexity increases sharply, which greatly improves the load capacity of the receiver’s data processor and reduces the output frequency of the positioning result. To achieve the balance between positioning accuracy and computational complexity, a new fast satellite selection algorithm based on both of geometry and geometric dilution of precision contribution is proposed. Firstly, this article analyzes the geometry characteristics of the least visible satellites has minimum geometric dilution of precision that meet the positioning requirements and makes clear the layout of their elevation angles and azimuth angles. In addition, it derives the relationship of geometric dilution of precision and the visible satellites layout and gets geometric dilution of precision contribution of each satellite. Finally, based on the observation data of JFNG tracking station of the Multi-Global Navigation Satellite System (GNSS) Experiment trial network, the positioning error and the elapsed time of GPS/Beidou Satellite Navigation System and GPS/Beidou Satellite Navigation System/Russian Global Orbiting Navigation Satellite System (GLOANSS) are compared. Simulation results show that the algorithm solves the problem that there are a lot of matrix multiplications and matrix inversions in the traditional satellite selection algorithm, and the new algorithm can reduce computational complexity and increase receiver processing speed.
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Nettleton, Greta S., and Emile G. McAnany. "Brazil's satellite system." Telecommunications Policy 13, no. 2 (June 1989): 159–66. http://dx.doi.org/10.1016/0308-5961(89)90040-2.
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Ильченко, Михаил Ефимович, Теодор Николаевич Нарытник, Владимир Ильич Присяжный, Сергей Владимирович Капштык, and Сергей Анатольевич Матвиенко. "ИССЛЕДОВАНИЕ ПОДХОДОВ К ПОСТРОЕНИЮ ОРБИТАЛЬНОЙ ВЫЧИСЛИТЕЛЬНОЙ СЕТИ СПУТНИКОВОЙ СИСТЕМЫ ИНТЕРНЕТА ВЕЩЕЙ." Aerospace technic and technology, no. 8 (August 31, 2019): 138–51. http://dx.doi.org/10.32620/aktt.2019.8.21.
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There are considered issues of building a Low-Earth-Orbit Satellite System designed to provide the Internet of Things services and adapted to the features of the services and systems of the Internet of Things. The considered system provides the creation of the necessary telecommunication infrastructure based on the Low-Earth-Orbit Broadband Access Satellite System and places Computational Facilities into the Low-Earth-Orbit for to ensure the processing of Internet of Things devices and systems information, and perform computations. The architecture of a “Distributed Satellite” was chosen to construct the telecommunications part of the Internets of Things Satellite System. The chosen architecture allows, on the one hand, to ensure the full functionality of complex telecommunication systems, and on the other hand, to use spacecraft of the form factor nano-satellite / cub-sat. The using of the cube-sat spacecraft for development of the satellite-based system allows to significantly reduce the cost of development of the system and the time of the system deploying. A promising direction in the development of the Internet of Things systems is the implementation of the concept of “Fog Computing” for processing Internet of Things information. To implement “Fog Computing”, it was proposed to include into the composition of each “Distributed Satellite” a separate Satellite-Computer and to build an Orbital Distributed Network based on Satellite-Computers. The issues of the inter-satellite connectivity are considered taking into account ensuring the connection between Satellites-Computers in the framework of the Orbital Distributed Computer Network using inter-satellite links between Distributed Satellites, the characteristics of the orbital construction of the Satellite System Constellation. It was proposed to create and deploy the Distributed Localized Database based on the Orbital Distributed Computer Network, for to ensure the continuous provision of Internet of Things services, taking into account the movement of spacecraft in the orbital plane and the rotation of the Earth. It was shown the direction of transmission of the operational part of a Localized Distributed Database. Proposals are made on the distribution of the excess computational load arising in certain regions of the satellite telecommunications system's service area, involving the resource of neighboring satellite computers in its orbital plane and neighboring orbital planes. An algorithm is proposed for moving the excess computational load to the polar and oceanic regions.
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Chandrashekar, M. G., V. Jayaramn, C. B. S. Dutt, and B. Manikiam. "Earth Observation System Plans of India." International Astronomical Union Colloquium 123 (1990): 531. http://dx.doi.org/10.1017/s0252921100077617.
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AbstractOperational methodologies are available to retrieve several parameters related to the land, air and oceans from satellite data which is capable of providing well calibrated data/observations over large areas giving a synoptic view on a repetitive and reliable basis. The capability of satellites to provide data in various spectral, spatial and temporal scales is of great advantage in studying the dynamic aspects of earth atmosphere system. The present day capabilities of satellites include spatial resolutions ranging from 10 m and above and repetition of a few hours (geosynchronous Satellite) to few days. Higher spatial resolutions and all weather capabilities (through microwave sensing) are becoming available in the immediate future. Towards utilising the potentials of space based systems, India has been operating INSAT series of satellite for weather monitoring and 1RS series of satellites for natural resources monitoring/management. The INSAT is a series of geostationary satellites stationed over Indian region to provide meteorological observations on a continuous basis in visible and thermal regions in addition to providing services for disaster warning related to Cyclones and remote location data collection platforms. The space based observations on meteorology over the past 5 years is proving to be a valuable data base for studies related to monsoon dynamics and tropical cyclones.
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Zhang, Liangyi, Shaohua Wu, Xiyu Lv, and Jian Jiao. "A Two-Step Handover Strategy for GEO/LEO Heterogeneous Satellite Networks Based on Multi-Attribute Decision Making." Electronics 11, no. 5 (March 3, 2022): 795. http://dx.doi.org/10.3390/electronics11050795.
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Low Earth Orbit (LEO) satellites can provide high-speed and low-delay services for terrestrial users; however, the rapid movement of LEO satellites and the insufficient size of the LEO constellations incurs the instability of the transmission links. The rapid movement of LEO satellites also leads to frequent handovers. Fortunately, GEO/LEO heterogeneous satellite systems can remedy this shortcoming. As the handover decision strategy which makes the selection among the available satellites will directly impact the performance of GEO/LEO heterogeneous satellite systems, we propose a two-step access and handover decision strategy for heterogeneous satellite networks in this paper. Firstly, a GEO/LEO network selection is carried out based on utility functions that reflect user’s QoS requirements. Then, the multi-attribute decision making (MADM) method is used to select the specific LEO satellite if users select LEO satellite network. We also propose an Importance-TOPSIS scheme to improve the weight setting for handover attributes. Simulation results show that the proposed method can reduce the number of handovers and the forced termination probability of the system, and the overall throughput of the system is also improved.
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RAJA, M., and O. PRAKASH. "Design of High Pointing Accuracy NPSAT-1 Satellite Attitude Systems of Armature Controlled DC Motor with utilization for PD Controller." INCAS BULLETIN 12, no. 1 (March 1, 2020): 145–56. http://dx.doi.org/10.13111/2066-8201.2020.12.1.14.
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An Attitude control system plays the important role to maintain the satellite to desired attitude orientations. The intended application of NANO satellite in low earth orbits (LEO) helps find transient responses with and without controllers. LEO satellites typically orbit at an altitude ranging between160-2000 km. LEO satellites are widely used for remote sensing, navigation, and military surveillance applications. The Nano NPSAT-1 satellite attitude control systems (ACS) are described in this research work. The high pointing accuracy attitude estimation and feedback control systems are presented. The design specifications have been taken to meet the accuracy requirements (desired value ≤ 0.2 seconds) of Nano satellite attitude control. The feedback signal from on-board sensors compared with reference orbit trajectory and implementation of the Proportional Derivative (PD) controller is constructed. An algorithm of Nano satellite (NPSAT-1) attitude control is implemented using MATLAB Tools. In addition, the closed loop poles help find the gain of the system using Root Locus (RL) methods. The satellite control system is used to improve the transient response like overshoot and settling time of the system. Thus, the design of attitude control to improve the rise time, the settling time, the maximum overshoot, and no steady state error was carried out.
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Radhakrishnan, Radhika, Qing-An Zeng, and William E. Edmonson. "Inter-Satellite Communications for Small Satellite Systems." International Journal of Interdisciplinary Telecommunications and Networking 5, no. 3 (July 2013): 11–22. http://dx.doi.org/10.4018/jitn.2013070102.
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Small satellite technology has opened a new era in aerospace engineering by decreasing space mission costs, without greatly reducing the performance. The concept of formation flying using small satellites is becoming popular because of their potential to perform coordinated measurements of remote sensing space missions. The current state of art in satellite communications is a one hop link between satellite and ground station. Very little work has been done on inter-satellite communications. This paper aims to design and evaluate feasible MAC and routing layer protocols for distributed small satellite networks. The possibility to implement proposed MAC and routing protocols for two different formation flying patterns are investigated. To validate the authors’ proposed system model, they use extensive simulations to evaluate the performance of the system using throughput, access delay and end-to-end delay.
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Li, Fangchao, Zengke Li, Jingxiang Gao, and Yifei Yao. "A Fast Rotating Partition Satellite Selection Algorithm Based on Equal Distribution of Sky." Journal of Navigation 72, no. 04 (February 21, 2019): 1053–69. http://dx.doi.org/10.1017/s0373463318001145.
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To achieve fast satellite selection for a multi-Global Navigation Satellite System (GNSS), thereby reducing the burden on a receiver's processing element and the cost of hardware, and improving the utilisation ratio of receiver signal channels, the relationship between the number of satellites and Geometric Dilution Of Precision (GDOP), the number of satellites selected and the computation time is analysed. A fast rotating partition algorithm for satellite selection based on equal distribution of the sky is proposed. The algorithm divides the satellite selection process into two parts: rough selection and detailed selection. Unhealthy satellites, according to a health identifier, and low elevation angle satellites with a large troposphere delay are eliminated during the rough selection process. During the detailed satellite selection process, the satellite sky is divided and rotated to match satellites based on the average angle distance between the satellite and central partition line. Static data from the International GNSS Service (IGS) station and dynamic data collected at China University of Mining and Technology were used to verify the algorithm, and the results demonstrated that an inverse matrix could be avoided to reduce computation complexity. Additionally, the new satellite selection algorithm has the merit that there is little effect on the computation when the selected satellites and number of satellites in the field increased. A single system of the Global Positioning System (GPS) and double system of GPS/Globalnaya Navigazionnaya Sputnikovaya Sistema (GLONASS) both passed the hypothesis test for each epoch. By including BeiDou Navigation Satellite System (BDS) data, data utilisation increased to more than 95% using the rotating partition algorithm. Also, the GDOP and positioning performance of a rotating partition algorithm and an optimal Dilution Of Precision (DOP) algorithm are compared in this paper, and the analysis result shows that both of the algorithms have only a small difference of GDOP and have comparable positioning performance.
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Channumsin, Sreesawet, Saroj, Saingyen, Puttasuwan, Udomthanatheera, and Jaturut. "Development of Space Traffic Management System: ZIRCON." Proceedings 39, no. 1 (January 7, 2020): 12. http://dx.doi.org/10.3390/proceedings2019039012.
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In near future, commercial companies have proposed to launch the extreme large constellation of small to medium-sized satellites over new 20,000 satellites in orbit. As a result, satellite operators will face a new challenge and have to prepare some solutions to mitigate huge potential collision risks. Under current practices, operators receive collision warning messages (Conjunction Data Messages: CDMs) generated by the Combined Space Operations Center (CSpOC). It is possibly to receive huge conjunctions that exceed warning threshold control each day but many of them are false conjunctions because the result of a combination of inaccuracies in the sensor measurements, predicting error and especially inadequacy of satellite information (e.g., GPS data and satellite size) To reduce the false CDMs and effectively mitigate the potential risk in time, space traffic management system can minimize the problems. The key system capabilities are able to automatically screen potential risky objects and provide an analysis tool to decide effective maneuver planning. As a result, GISTDA initiates the project to develop the space traffic management system known as “ZIRCON” to monitor and mitigate the risk of GISTDA’s satellites and future satellites (e.g., THEOS2 project). This paper presents the operational collision avoidance process and algorithm analysis of space traffic management system. The accuracy of analysis results is validated by comparing the analyzed results of CSpOC and Space Data Association (SDA) serving the commercial space sector to monitor and provide warning message for membership. The last section describes the future development planning and services for satellite operators.
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He, Yongming, Yuan Wang, Yingwu Chen, and Lining Xing. "Auto Mission Planning System Design for Imaging Satellites and Its Applications in Environmental Field." Polish Maritime Research 23, s1 (October 1, 2016): 59–70. http://dx.doi.org/10.1515/pomr-2016-0047.
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Abstract Satellite hardware has reached a level of development that enables imaging satellites to realize applications in the area of meteorology and environmental monitoring. As the requirements in terms of feasibility and the actual profit achieved by satellite applications increase, we need to comprehensively consider the actual status, constraints, unpredictable information, and complicated requirements. The management of this complex information and the allocation of satellite resources to realize image acquisition have become essential for enhancing the efficiency of satellite instrumentation. In view of this, we designed a satellite auto mission planning system, which includes two sub-systems: the imaging satellite itself and the ground base, and these systems would then collaborate to process complicated missions: the satellite mainly focuses on mission planning and functions according to actual parameters, whereas the ground base provides auxiliary information, management, and control. Based on the requirements analysis, we have devised the application scenarios, main module, and key techniques. Comparison of the simulation results of the system, confirmed the feasibility and optimization efficiency of the system framework, which also stimulates new thinking for the method of monitoring environment and design of mission planning systems.
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SAKAI, Takeyasu. "Relocation of Satellites Adjacent to a Failed Satellite for the Quasi-Zenith Satellite System." JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 60, no. 6 (2012): 221–26. http://dx.doi.org/10.2322/jjsass.60.221.
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Ma, Chao, Jun Yang, Jianyun Chen, and Yinyin Tang. "Time synchronization requirement of global navigation satellite system augmentation system based on pseudolite." Measurement and Control 52, no. 3-4 (February 28, 2019): 303–13. http://dx.doi.org/10.1177/0020294019827329.
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Global navigation satellite systems are widely used across the world because of their continuous/all-weather, global coverage, and high precision positioning. But, three-dimensional positioning accuracy, especially in the vertical direction, remains insufficient because of the geometric distribution of satellites. This is especially true for air-borne objects such as unmanned aerial vehicles, civil aviation devices, and missiles. To solve this problem, we adopt a satellite-ground joint positioning system based on a pseudo-satellite (pseudolite). The introduction of ground pseudolites can significantly reduce the vertical dilution of precision and improve positioning accuracy. This method has been proposed in the 1980s. However, we have to ask a question, as long as we add a pseudolite, can the positioning accuracy be improved? The answer is no. Pseudolites can cause time synchronization problems with satellites, and the resulting timing errors of the pseudolite are converted into pseudorange errors, reducing accuracy. Here, we seek to evaluate the impact of the reduced vertical dilution of precision and the increased range errors associated with the introduction of a pseudolite on the ground. We derive a mathematical formula to explain this relationship. We conclude that when the satellite range error and the change in the position dilution of precision associated with a pseudolite are known, we can calculate an approximate limit for the pseudolite timing accuracy to ensure that the use of the pseudolite improves the positioning accuracy. This work should be of great value in guiding engineering practice.
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Soleymani, Ahmad, and Mehran Nosratollahi. "Simulation of thermal distribution system of microsatellite equipped with FMC actuators." Aircraft Engineering and Aerospace Technology 92, no. 10 (August 12, 2020): 1505–12. http://dx.doi.org/10.1108/aeat-11-2019-0213.
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Purpose The purpose of this paper is to simulate the thermal performance of fluidic momentum controller (FMC) actuators in two case, with and without thermal distribution system on a three-axis configuration of FMC actuators to an orbital period of satellite. The results show the effectiveness of using a storage with FMC actuators. Design/methodology/approach One of the challenges during a satellite’s orbital mission is unpredictable external temperature perturbations. This system used as a collaborative thermal subsystem for microsatellite temperature passive control. The operating principles of the system are that each fluid rings are used in a microsatellite surface with pumps to stabilize the satellite. All fluid rings are connected to the satellite thermal distribution system (storage). Findings Simulation results show that with using of thermal distribution system, damping of satellite different surfaces temperature is rapidly possible to the event of thermal disturbances. Practical implications Numerical simulation is obtained by ANSYS Fluent software and pressure-velocity coupling is SIMPLE method and spatial discretization is second order accurate and first order in time, viscous model is k-e. In this regard, a solver algorithm is also developed. Originality/value In space research fields about FMC application as actuators to satellite system design, main goal is to research about role of this system to attitude and determination control system (ADCS) of satellites, and no study is performed on its role to satellite temperature damping. This study is exclusively simulated thermal distribution system (includes a storage and its connections) of a microsatellite equipped with FMC actuators. The idea of using a storage for FMC actuators is the innovative step of this research.
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Pichugin, S. B. "Simplest Flow Queuing Models for LEO Satellite System." Proceedings of Higher Educational Institutions. Маchine Building, no. 1 (742) (January 2022): 61–70. http://dx.doi.org/10.18698/0536-1044-2022-1-61-70.
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The relevance of the work is associated with the active deployment of low-orbit communication systems and the expansion of research in the field of corresponding satellite systems. A promising low-orbit communication system based on relay satellites with the function (RSRFs) of routing message packets is considered. The low earth orbit communications systems use the BGP protocol and the AAA functionality at the ground station. For assessing the characteristics of RSRF inter-satellite paths, a scenario was created for the message packets arrival from a group of inter-satellite paths to one subscriber path. The corresponding analytical models have been developed using the mathematical apparatus of queuing systems with the simplest flows of requests and exponential distribution of the service time. The RSRF characteristics of a promising low-orbit communication system are predicted. It is proposed to make the mathematical apparatus of analytical models more complicated to take into account the dynamics of displacements and failures of the RSRF in a low-orbit communication system.
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Shen, Fei, Mingming Sui, Yifan Zhu, Xinyun Cao, Yulong Ge, and Haohan Wei. "Using BDS MEO and IGSO Satellite SNR Observations to Measure Soil Moisture Fluctuations Based on the Satellite Repeat Period." Remote Sensing 13, no. 19 (October 3, 2021): 3967. http://dx.doi.org/10.3390/rs13193967.
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Soil moisture is an important geophysical parameter for studying terrestrial water and energy cycles. It has been proven that Global Navigation Satellite System Interferometry Reflectometry (GNSS-IR) can be applied to monitor soil moisture. Unlike the Global Positioning System (GPS) that has only medium earth orbit (MEO) satellites, the Beidou Navigation Satellite System (BDS) also has geosynchronous earth orbit (GEO) satellites and inclined geosynchronous satellite orbit (IGSO) satellites. Benefiting from the distribution of three different orbits, the BDS has better coverage in Asia than other satellite systems. Previous retrieval methods that have been confirmed on GPS cannot be directly applied to BDS MEO satellites due to different satellite orbits. The contribution of this study is a proposed multi-satellite soil moisture retrieval method for BDS MEO and IGSO satellites based on signal-to-noise ratio (SNR) observations. The method weakened the influence of environmental differences in different directions by considering satellite repeat period. A 30-day observation experiment was conducted in Fengqiu County, China and was used for verification. The satellite data collected were divided according to the satellite repeat period, and ensured the response data moved in the same direction. The experimental results showed that the BDS IGSO and MEO soil moisture estimation results had good correlations with the in situ soil moisture fluctuations. The BDS MEO B1I estimation results had the best performance; the estimation accuracy in terms of correlation coefficient was 0.9824, root mean square error (RMSE) was 0.0056 cm3cm−3, and mean absolute error (MAE) was 0.0040 cm3cm−3. The estimations of the BDS MEO B1I, MEO B2I, and IGSO B2I performed better than the GPS L1 and L2 estimations. For the BDS IGSO satellites, the B1I signal was more suitable for soil moisture retrieval than the B2I signal; the correlation coefficient was increased by 19.84%, RMSE was decreased by 42.64%, and MAE was decreased by 43.93%. In addition, the BDS MEO satellites could effectively capture sudden rainfall events.
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Lee, Hak-Beom, Ki-Ho Kwon, and Jong-Hoon Won. "Feasibility Analysis of GPS L2C Signals for SSV Receivers on SBAS GEO Satellites." Remote Sensing 14, no. 21 (October 25, 2022): 5329. http://dx.doi.org/10.3390/rs14215329.
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This paper analyzes the feasibility of Global Positioning System (GPS) L2C signals for use with the space service volume (SSV) receiver on satellite-based augmentation system (SBAS) geostationary orbit (GEO) satellites equipped with L1 and L5 band signal transmitters. Augmentation signals transmitted at L1 and L5 bands from SBAS GEO satellites may interfere with the same bands of SSV GPS-receiving antennas. Therefore, the use of L1 and L5 band signals for the GPS SSV receiver on SBAS GEO satellites is prohibited, and the GPS L2C signal is selected. Unlike ground systems, the various constraints of space exploration in GEO should be considered. Therefore, signal feasibility analysis is essential before considering the use of new global navigation satellite system (GNSS) signals in GEO. This paper presents satellite visibility, dilution of precision, and navigation solution error when the GPS L2C signal is used in GEO satellites through numerical simulation.
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Conti, G. T., and L. C. G. Souza. "Satellite Attitude Control System Simulator." Shock and Vibration 15, no. 3-4 (2008): 395–402. http://dx.doi.org/10.1155/2008/141465.
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Future space missions will involve satellites with great autonomy and stringent pointing precision, requiring of the Attitude Control Systems (ACS) with better performance than before, which is function of the control algorithms implemented on board computers. The difficulties for developing experimental ACS test is to obtain zero gravity and torque free conditions similar to the SCA operate in space. However, prototypes for control algorithms experimental verification are fundamental for space mission success. This paper presents the parameters estimation such as inertia matrix and position of mass centre of a Satellite Attitude Control System Simulator (SACSS), using algorithms based on least square regression and least square recursive methods. Simulations have shown that both methods have estimated the system parameters with small error. However, the least square recursive methods have performance more adequate for the SACSS objectives. The SACSS platform model will be used to do experimental verification of fundamental aspects of the satellite attitude dynamics and design of different attitude control algorithm.
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Zou, Cheng, Haiwang Wang, Shiyi Xia, Jiachao Chang, Fengwei Shao, Lin Shang, Yuemei Hu, and Guotong Li. "A Framework for Assessing the Interference from NGSO Satellite Systems to a Radio Astronomy System." Applied Sciences 13, no. 3 (January 29, 2023): 1691. http://dx.doi.org/10.3390/app13031691.
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As the number of non-geostationary orbit (NGSO) satellites continues to grow, interference with other communication systems, including radio astronomy systems (RASs), is becoming increasingly critical. In this study, an interference simulation framework was developed to analyse the potential impact of NGSO systems on RAS in accordance with the relevant International Telecommunication Union (ITU) regulations and recommendations. In addition to the simulation of interference generated by individual NGSO satellite systems, the framework also supports the analysis of aggregate interference from multiple NGSO satellite systems. By inputting satellite system parameters, including constellation configuration, user distribution and beam scheduling strategy, the framework is able to obtain interference probability distributions for a typical RAS ground station at different latitudes and observation directions. The simulation results provide a reference for the analysis of interference from NGSO satellite systems to RASs, and can also be used to guide the development of strategies to mitigate harmful interference to RASs.
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Goldberg, M., G. Ohring, J. Butler, C. Cao, R. Datla, D. Doelling, V. Gärtner, et al. "The Global Space-Based Inter-Calibration System." Bulletin of the American Meteorological Society 92, no. 4 (April 1, 2011): 467–75. http://dx.doi.org/10.1175/2010bams2967.1.
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The Global Space-based Inter-Calibration System (GSICS) is a new international program to assure the comparability of satellite measurements taken at different times and locations by different instruments operated by different satellite agencies. Sponsored by the World Meteorological Organization and the Coordination Group for Meteorological Satellites, GSICS will intercalibrate the instruments of the international constellation of operational low-earth-orbiting (LEO) and geostationary earth-orbiting (GEO) environmental satellites and tie these to common reference standards. The intercomparability of the observations will result in more accurate measurements for assimilation in numerical weather prediction models, construction of more reliable climate data records, and progress toward achieving the societal goals of the Global Earth Observation System of Systems. GSICS includes globally coordinated activities for prelaunch instrument characterization, onboard routine calibration, sensor intercomparison of near-simultaneous observations of individual scenes or overlapping time series, vicarious calibration using Earth-based or celestial references, and field campaigns. An initial strategy uses high-accuracy satellite instruments, such as the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) and Atmospheric Infrared Sounder (AIRS) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT)'s Centre National d'Études Spatiales (CNES) Infrared Atmospheric Sounding Interferometer (IASI), as space-based reference standards for intercalibrating the operational satellite sensors. Examples of initial intercalibration results and future plans are presented. Agencies participating in the program include the Centre National d'Études Spatiales, China Meteorological Administration, EUMETSAT, Japan Meteorological Agency, Korea Meteorological Administration, NASA, National Institute of Standards and Technology, and NOAA.
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Kammeyer, P. C., H. F. Fliegel, and R. S. Harrington. "Optical Astrometry and the Global Positioning System." International Astronomical Union Colloquium 127 (1991): 284–87. http://dx.doi.org/10.1017/s0252921100064009.
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AbstractAstrometric accuracies of a few tens of milliarcseconds are expected to be attainable within five years by calibrating astrograph plates with optical observations of Global Positioning System (GPS) satellites against a stellar background. The line of sight from an observer on the Earth’s surface to a GPS satellite may be calculated with high accuracy. Motion on each day of the line of sight to the satellite and changes from day to day in the apparent path of the satellite are sufficiently slow to make it possible to reduce atmospheric errors by averaging. Advanced ground-based optical sensors, probably using charge coupled device technology, will be required for GPS optical astrometry.
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Popov, Alexander M., Ilya Kostin, Julia Fadeeva, and Boris Andrievsky. "Development and Simulation of Motion Control System for Small Satellites Formation." Electronics 10, no. 24 (December 14, 2021): 3111. http://dx.doi.org/10.3390/electronics10243111.
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In the paper, the problem of forming and maintaining the small satellites formation in the near-earth projected circular orbits is considered. The satellite formation reconfiguration and formation-keeping control laws are proposed by employing the passivity-based output feedback control. For the complete nonlinear and time-dependent dynamics of the relative motion of a pair of satellites in elliptical orbits, new combined control algorithms, including a consensus protocol, are proposed and analyzed. A comparison of the control modes using the passivity-based output feedback control and the proportional-differential controller with and without the consensus algorithm is given. On the basis of the passification method, the algorithm is obtained ensuring the stable motion of the slave satellite relative to the orbit of the master satellite. To improve the accuracy of the satellites’ positioning, a consensus protocol based on measurements of the relative positions of the satellites is proposed and studied. Computer simulations of the proposed algorithms for options to construct formations are provided for two projected circular orbits of 8 satellites, demonstrating the efficiency of the proposed control schemes. It is shown that the resulting passivity-based output feedback control provides better accuracy than the PD controller. It is also shown that the use of the consensus protocol further increases the positioning accuracy of the satellite constellation.
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Lord, Stephen, George Gayno, and Fanglin Yang. "Analysis of an Observing System Experiment for the Joint Polar Satellite System." Bulletin of the American Meteorological Society 97, no. 8 (August 1, 2016): 1409–25. http://dx.doi.org/10.1175/bams-d-14-00207.1.
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Abstract The Joint Polar Satellite System (JPSS) is a key contributor to the next-generation operational polar-orbiting satellite observing system. In the JPSS era, the complete polar-orbiting observing system will be composed of two satellites—in the midmorning (mid-AM) and afternoon (PM) orbits—each with thermodynamic sounding capabilities from both microwave and hyperspectral infrared instruments. JPSS will occupy the PM orbit, while the Meteorological Operational (MetOp) system, sponsored by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), will occupy the mid-AM orbit. While the current polar-orbiting satellite system has been thoroughly evaluated, information about its resilience and efficacy in the JPSS era is needed. A 7-month (August 2012–February 2013) observing system experiment (OSE) was run with the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS). Observations were selected from operational satellite data platforms to be representative of the polar-orbiting data in the JPSS era. Overall, removing data from the PM orbit produced inferior scores, with the impact greater in the Southern Hemisphere (SH) than in either the Northern Hemisphere (NH) or the tropics. For the entire 7 months, the time-mean 500-hPa geopotential height anomaly correlation (Z500AC) decreased by 0.005 and 0.013 in the NH and SH, respectively—both of which are statistically significant at the 95% level. Additionally, a detailed statistical analysis of the distribution of Z500AC skill scores is presented and compared with historical accuracy data. It was determined that eliminating PM orbit data resulted in a higher probability of producing low scores and a lower probability of producing high scores, counter to the trend in GFS forecast skill over the last 20 years.
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Khomsin, Ira Mutiara Anjasmara, Danar Guruh Pratomo, and Wahyu Ristanto. "Accuracy Analysis of GNSS (GPS, GLONASS and BEIDOU) Obsevation For Positioning." E3S Web of Conferences 94 (2019): 01019. http://dx.doi.org/10.1051/e3sconf/20199401019.
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Global Navigation Satellite System called GNSS is a term used for the entire global navigation that already operate or are in the planning for the future. Some of the satellite that can be used are GPS (Global Positioning System) operated by USA, GLONASS (Global Navigation Satellite System) operated by Rusia and BeiDou/Compass operated by China. Many errors and biases that occur when measuring with GNSS in the field. Theoritically, there are some errors and biases that can be eliminated or subtracted by strength of satellite geometric. One factor to get a good satellite geometric is to increase the number of satellites received by receiver. In general, the more number of satellites received, the better the geometric satellites received by receivers. The development of receiver technology is currently able to capture GPS, GLONASS and BeiDou signals at one time. Thus the receiver can receive many satellites and finally the shape of geometric satellite becomes better. HiTarget V30 is one of the latest GNSS technology on the market today. This receiver is capable of receiving GPS signals, GLONASS and BeiDou at one time of observation. This research will compare the accuracy of positioning using GPS, GLONASS and BeiDou satellite.
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Zhou, Li. "Optical System in Laser Inter-Satellites Communication." Advanced Materials Research 945-949 (June 2014): 2213–16. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.2213.
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We know that Inter-satellites communica-tion is a very important to us.However, real global coverage can only be achieved by satellite systems. Satellites communication is the most important mean of the communication network. The traditional satellites communication and inter-satellites links are built by microwave. Recent years, laser links for inter-satellites communication are becoming more and more important.
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Hidri, Lotfi, Mehdi Mrad, and Mohammed Alkahtani. "Suitable Mass Density Function for an Artificial Satellite to Prevent Chaotic Motion after Collision with Space Debris." Symmetry 14, no. 4 (April 14, 2022): 818. http://dx.doi.org/10.3390/sym14040818.
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Artificial satellites are widely used in different areas such as communication, position systems, and agriculture. The number of satellites orbiting Earth is becoming huge, and many are set to be launched soon. This huge number of satellites in addition to space debris are sources of concern. Indeed, some incidents have occurred either between satellites or because of space debris. These incidents are a threat for the hit satellite and can be a source of irreversible damages. A hit satellite may diverge to a chaotic motion with all the entailed consequences. The inertia moment of a satellite is a main factor to determine if the hit satellite is heading toward a chaotic motion or not. The inertia moment is determined over the mass density function. In this paper, a circularly orbiting artificial satellite was modeled as a thin rotating rod. The objective was to determine a suitable mass density function for this satellite allowing the prevention as much as possible of the chaotic motion after being hit. This unknown density mass function satisfies a system of equations reflecting some physical constraints. Conventional procedures are not applicable to solve this system of equations. The presented resolution method is based on several mathematical transformations, allowing converting this system into a highly nonlinear one with several unknowns. Several mathematical techniques were applied, and an analytical solution was obtained. Finally, from the mechanical engineering point of view, the obtained mass density function corresponds to a Functionally Graded Material (FGM).
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Zong, Zhu Lin, Jian Hao Hu, and Li Dong Zhu. "Estimation of Doppler Parameter for Formation-Flying Satellite SAR System." Applied Mechanics and Materials 44-47 (December 2010): 3473–77. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.3473.
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In formation-flying satellite SAR system, especially the satellites are LEO or MEO, Doppler frequency shift of SAR echo has a character of long-range changes and quick time variation. Because of this, imaging with high quality become difficulty. Based on the theories and methods of universal gravitation, the relative positions and velocities between every satellite and the ground detection center can be computed, then the Doppler frequency shift for formation-flying satellite SAR system can be estimated that only need to known the parameters of satellite orbit, the working frequency and the azimuth of antenna of master satellite radar. The simulation results show that by using this method, the scope of Doppler frequency shift can be reduced to a very small range, about two in a thousand compared to original echo.
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Bhardwaj, Ashutosh. "Terrestrial and Satellite-Based Positioning and Navigation Systems—A Review with a Regional and Global Perspective." Engineering Proceedings 2, no. 1 (November 14, 2020): 41. http://dx.doi.org/10.3390/ecsa-7-08262.
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Satellite-based navigation techniques have revolutionized modern-day surveying with unprecedented accuracies along with the traditional and terrestrial-based navigation techniques. However, the satellite-based techniques gain popularity due to their ease and availability. The position and attitude sensors mounted on satellites, aerial, and ground-based platforms as well as different types of equipment play a vital role in remote sensing providing navigation and data. The presented review in this paper describes the terrestrial (LORAN-C, Omega, Alpha, Chayka) and satellite-based systems with their major features and peculiar applications. The regional and global navigation satellite systems (GNSS) can provide the position of a static object or a moving object i.e., in Kinematic mode. The GNSS systems include the NAVigation Satellite Timing And Ranging Global Positioning System (NAVSTAR GPS), of the United States of America (USA); the Globalnaya navigatsionnaya sputnikovaya sistema (GLObal NAvigation Satellite System, GLONASS), of Russia; BEIDOU, of China; and GALILEO, of the European Union (EU). Among the initial satellite-based regional navigation systems included are the TRANSIT of the US and TSYKLON of what was then the USSR which became operational in the 1960s. Regional systems developed in the last decade include the Quasi-Zenith Satellite System (QZSS) and the Indian Regional Navigation Satellite System (IRNSS). Currently, these global and regional satellite-based systems provide their services with accuracies of the order of 10–20 m using the trilateration method of surveying for civil use. The terrestrial and satellite-based augmented systems (SBAS) were further developed along with different surveying techniques to improve the accuracies up to centimeters or millimeter levels for precise applications.
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Zhang, Lei, and Bo Xu. "Navigation Performance of the Libration Point Satellite Navigation System in Cislunar Space." Journal of Navigation 68, no. 2 (September 18, 2014): 367–82. http://dx.doi.org/10.1017/s0373463314000617.
Full textAbstract:
Based on the candidate architectures of the libration point satellite navigation system proposed in our previous work, a navigation performance study is conducted in this paper to verify the cislunar navigation ability of the proposed system. Using scalar satellite-to-satellite range measurement between the user and libration point navigation satellites, a virtual lunar exploration mission scenario is developed to verify the navigation performance of the candidate Earth-Moon L1,2,4,5 four-satellite constellations. The simulation results indicate that the libration point satellite navigation system is available for cislunar navigation and the navigation accuracy of a few tens of metres can be achieved for both the trans-lunar cruise and lunar orbit phase. Besides that, it is also found that the navigation accuracy of the libration point satellite navigation system is sensitive to the orbit of the L1 satellite. Once the L1 navigation satellite is located in the Halo orbit or vertical Lyapunov orbit, the proposed system can present a better navigation performance in cislunar space.
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Gu, Neng Hua, and Ting You. "Improvement of Passive Location Precision Using ‘Beidou’ Navigation System." Advanced Materials Research 383-390 (November 2011): 7099–103. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.7099.
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This article raises an improved program of adding Pseudo-Satellite’s pseudo-range measurement and setting best configuration for Pseudo-Satellite in mentioned program on the basis of existing Binary System [1]. Through comparison and analysis of improved Tri-satellite System and existing Binary System, this article proves that it shortens location time and location precision by adding Pseudo-Satellite to Binary Navigation Location System. Finally this conclusion is approved by simulating Mathematical model using software.
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Meng, Fan Qin, Xu Hai Yang, Ji Kun Ou, and Pei Wei. "Method of Determining Satellite Clock Error by Using Observation Data of Satellite-Ground and Inter-Satellite." Advanced Materials Research 718-720 (July 2013): 474–79. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.474.
Full textAbstract:
We have done some simulate analysis on GPS data in this paper. The main research is method of determining satellite clock error by usining observation data of satellite-ground and inter-satellite under the condition of regional station arrangement. The research method is as follows: when the satellite in the visible area of regional observation network, we can get satellite clock error directly by satellite-ground time comparison, and predict the satellite clock error in invisible area. When the satellite in the invisible area of regional observation network, if this satellite can establish inter-satellite links with other satellites in the visible area, then the satellite clock error can be determined by time comparison of satellite-ground and inter-satellite; If there is no inter-satellite link between this satellite and other satellites in the visible area, then we can only predict the satellite clock error by given data. The simulation conditions of this paper are as follows: the system error of satellite-ground is 0.5 ns, the random error is 0.5 ns; the system error of inter-satellite is 1 ns, the random error is 0.5 ns. In this case, we can obtain the satellite clock error of PRN02 in an orbital period by method of this paper, and the accuracy is about 1.3 ns.
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Fischer, Christian, Winfried Halle, Thomas Säuberlich, Olaf Frauenberger, Maik Hartmann, Dieter Oertel, and Thomas Terzibaschian. "Small Satellite Tools for High-Resolution Infrared Fire Monitoring." Journal of Imaging 8, no. 2 (February 16, 2022): 49. http://dx.doi.org/10.3390/jimaging8020049.
Full textAbstract:
Space-borne infrared remote sensing specifically for the detection and characterization of fires has a long history in the DLR Institute of Optical Sensor Systems. In the year 2001, the first DLR experimental satellite, Bi-spectral Infrared Detection (BIRD), was launched after an intensive test period with cooled IR sensor systems on airborne systems. The main basis for the development of the FireBIRD mission with the two satellites, Technology Erprobungsträger No 1 (TET-1) and Bi-spectral-Infrared Optical System (BIROS), was the already space-proven sensor and satellite technology with successfully tested algorithms for fire detection and quantification in the form of the so-called fire radiation power (FRP). This paper summarizes the development principles for the IR sensor system of FireBIRD and the most critical design elements of the TET-1 and BIROS satellites, especially concerning the attitude control system—all very essential tools for high-resolution infrared fire monitoring. Key innovative tools necessary to increase the agility of small IR satellites are discussed.
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Liu, Chan, Liping Chen, Jianwan Ding, and Duansen Shangguan. "Modeling of Satellite Constellation in Modelica and a PHM System Framework Driven by Model Data Hybrid." Electronics 11, no. 14 (July 9, 2022): 2155. http://dx.doi.org/10.3390/electronics11142155.
Full textAbstract:
The new generation of low-earth-orbit (LEO) satellite constellation systems has the characteristics of low delay, strong signal and global coverage, and it is an important direction for the development of next-generation communication technology. A major disadvantage is that the constellation system is huge, often composed of hundreds or thousands of satellites, which puts forward high requirements for the design and health management of the constellation system, and the existing telemetry data monitoring system cannot meet the actual needs. CPS is a multidimensional complex system that integrates computation, communication and control (3C). Through the deep integration and cooperation of 3C, the real-time monitoring and dynamic control of large-scale engineering systems are realized, which is completely suitable for the operation and maintenance requirements of the satellite constellation system. This paper firstly establishes the entire satellite constellation system model, which is integrated from the satellite multidomain system, the constellation orbit environment system and the communication link system. Then, according to the technical concept of cyber-physical systems (CPS), an implementation framework of a prognostics and health (PHM) system driven by a model–data hybrid for satellite constellation systems is proposed. The framework is based on model simulation data and telemetry data and combines virtual and real data fusion, fault diagnosis, simulation prediction and other technologies to generate enhanced data to drive the effective operation of the PHM system. Finally, a verification case is designed to prove that the satellite constellation health management system implemented under this framework has a positive effect on the reliable operation and maintenance of the satellite constellation system.