scholarly journals Analysis of key technologies for creating multisatellite orbital constellations of small spacecraft

2021 ◽  
Vol 11 (4) ◽  
pp. 478-499
Author(s):  
I.S. Tkachenko ◽  

One of the key areas of modern world cosmonautics is the development of cluster space systems for various purposes, consisting of a large number of functioning spacecraft. This became possible due to a decrease in the mass of spacecraft due to the creation and use of new materials, the development of electronics and microelectromechanical systems, the use of the group launch method, the development of multi-agent technologies and inter-satellite communication sys-tems. There are projects of systems consisting of a large number of space objects, such as OneWeb, Planet, Starlink, Satellogic, etc. The main classes of devices used to create such multi-satellite systems are small satellites, including the number of micro (up to 100 kg) and nano (up to 10-15 kg) classes, which have significant advantages over heavy space-craft, especially in terms of the timing and cost of their creation. The deployment of multi-satellite constellations, in-cluding hundreds and thousands of satellites, requires fundamentally new approaches to the creation of spacecraft and the system as a whole at all stages of the life cycle. The article discusses the key technologies used to create multi-satellite orbital constellations based on small satellites at different stages of the life cycle - from the early stages of de-sign to the stage of operation and disposal (information from orbit). The experience of a joint project of Samara Univer-sity and the Progress Rocket and Space Center on the creation of a constellation of small spacecraft of the AIST series is presented.

Author(s):  
N. Rodigina ◽  
S. Moleva ◽  
M. Logina ◽  
V. Musikhin

This article is devoted to digitalization as a challenge of the modern world economy. The digital revolution has changed our lives and societies with unprecedented speed and scale, providing huge opportunities as well as daunting challenges. New technologies can make a significant contribution to achieving sustainable development goals, but positive results should not be taken for granted.


Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.


2021 ◽  
Vol 11 (13) ◽  
pp. 6079
Author(s):  
Abulasad Elgamoudi ◽  
Hamza Benzerrouk ◽  
G. Arul Elango ◽  
René Landry

A single Radio-Frequency Interference (RFI) is a disturbance source of modern wireless systems depending on Global Navigation Satellite Systems (GNSS) and Satellite Communication (SatCom). In particular, significant applications such as aeronautics and satellite communication can be severely affected by intentional and unintentional interference, which are unmitigated. The matter requires finding a radical and effective solution to overcome this problem. The methods used for overcoming the RFI include interference detection, interference classification, interference geolocation, tracking and interference mitigation. RFI source geolocation and tracking methodology gained universal attention from numerous researchers, specialists, and scientists. In the last decade, various conventional techniques and algorithms have been adopted in geolocation and target tracking in civil and military operations. Previous conventional techniques did not address the challenges and demand for novel algorithms. Hence there is a necessity for focussing on the issues associated with this. This survey introduces a review of various conventional geolocation techniques, current orientations, and state-of-the-art techniques and highlights some approaches and algorithms employed in wireless and satellite systems for geolocation and target tracking that may be extremely beneficial. In addition, a comparison between different conventional geolocation techniques has been revealed, and the comparisons between various approaches and algorithms of geolocation and target tracking have been addressed, including H∞ and Kalman Filtering versions that have been implemented and investigated by authors.


2020 ◽  
Vol 56 (07) ◽  
pp. 40-46
Author(s):  
Khayala Mugamat Mursaliyeva ◽  

The explosion of information and the ever-increasing number of international languages make the modern language situation very difficult. The interaction of languages ultimately leads to the creation of international artificial languages that operate in parallel with the world`s languages. The expansion of interlinguistic issues is a natural consequence of the aggravation of the linguistic landscape of the modern world. The modern interlinguistic dialect, which is defined as a field of linguistics that studies international languages and international languages as a means of communication, deals with the importance of overcoming the barrier.The problem of international artificial languages is widely covered in the writings of I.A.Baudouin de Courtenay, V.P.Qrigorev, N.L.Gudskov, E.K.Drezen, A.D.Dulchenko, M.I.Isayev, S.N.Kuznechov, A.D.Melnikov and many other scientists. Key words:the concept of natural language, the concept of artificial language, the degree of artificiality of language, the authenticity of language


Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2909
Author(s):  
Chen Zhang ◽  
Jiangtao Yang ◽  
Yong Zhang ◽  
Ziwei Liu ◽  
Gengxin Zhang

Beam hopping technology is considered to provide a high level of flexible resource allocation to manage uneven traffic requests in multi-beam high throughput satellite systems. Conventional beam hopping resource allocation methods assume constant rainfall attenuation. Different from conventional methods, by employing genetic algorithm this paper studies dynamic beam hopping time slots allocation under the effect of time-varying rain attenuation. Firstly, a beam hopping system model as well as rain attenuation time series based on Dirac lognormal distribution are provided. On this basis, the dynamic allocation method by employing genetic algorithm is proposed to obtain both quantity and arrangement of time slots allocated for each beam. Simulation results show that, compared with conventional methods, the proposed algorithm can dynamically adjust time slots allocation to meet the non-uniform traffic requirements of each beam under the effect of time-varying rain attenuation and effectively improve system performance.


2016 ◽  
Author(s):  
Rebecca Kennison

Officially launched just over a year ago, the Open Access Network (OAN)offers a transformative, sustainable, and scalable model of open access(OA) publishing and preservation that encourages partnerships amongscholarly societies, research libraries, and other partners (e.g., academicpublishers, university presses, collaborative e-archives) who share acommon mission to support the creation and distribution of open researchand scholarship and to encourage more affordable education, which can be adirect outcome of OA publishing. Our ultimate goal is to develop acollective funding approach that is fair and open and that fully sustainsthe infrastructure needed to support the full life-cycle for communicationof the scholarly record, including new and evolving forms of researchoutput. Simply put, we intend to *Make Knowledge Public*.


Author(s):  
Н.В. ВАРЛАМОВ ◽  
С.С. УВАРОВ

Выполнен анализ интенсивности использования геостационарной орбиты (ГСО) и негеостационарных орбит (НГСО) современными системами спутниковой связи фиксированной спутниковой службы в Ки-, Ка- и Q/V-диапазонах частот. Исследование охватывает ГСО, а также два наиболее используемых сегмента НГСО с высотой апогея до 1500 км и выше 8000 км. Представлены также результаты исследований для высокоэллиптических орбит (ВЭО). Сделан вывод о дефиците орбитально-частотного ресурса на ГСО и НГСО для рассматриваемых диапазонов частот. The paper analyzes the intensity of the use of geostationary orbit (GSO) and non-geostationary orbits (non-GSO) by modern satellite communication systems of the fixed-satellite service in the Ku-, Ka- and Q/V-bands. The analysis is made for geostationary orbit and two most used segments of non-GSO orbits with apogee altitudes up to 1500 km and above 8000 km. Results for highly inclined elliptical orbits (HEO) are also presented. The analysis results show a shortage of orbital and frequency resources in GSOs and non-GSOs for the considered frequency bands.


Author(s):  
Jeroen Duindam

The turbulent decades around 1800 did not spell the end of dynasty, but they carried the message that alternative forms of power might in the long run gain ascendancy. While royal legitimacy was now openly contested, republics remained the exception until 1918. ‘The dynastic impulse in the modern world’ considers the breakdown of empires that led to the creation of new states, many of them monarchies. It shows how modern autocrats mimic forms of dynastic representation, promoting their families, and designating their own successors. Finally, it highlights the remarkable continuities of dynastic practice in ‘political families’ and family businesses around the world.


2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anna Wojewnik-Filipkowska ◽  
Anna Dziadkiewicz ◽  
Wioleta Dryl ◽  
Tomasz Dryl ◽  
Robert Bęben

Purpose Public involvement is essential in the creation of effective local strategies for the development of a sustainable built environment, yet there has been little research on stakeholder motivation and engagement in the creation of infrastructure-project value, in the entire life cycle of a given project, while different markets show that overlooking stakeholders can negatively affect the success of an infrastructure project. The purpose of this paper is to fill the theory-practice gap that has been discerned, and thus study how early public involvement determines the success of an infrastructure project, which is identified with its value creation (effectiveness, sustainability and utility). Design/methodology/approach This research entails a combination of methods. A case study analysis allowed observation of the role the stakeholders play and of how the relationships, perspectives, expectations and risks, along with other soft issues, continue to affect projects. The case study required comprehensive examination of project documentation and conduction of interviews. To collect data, focused group interviews and semi-structured interviews were used, supported with direct questionnaire surveys. Findings The study provides evidence that early public engagement can contribute to infrastructure-project value (effectiveness, sustainability and utility). Practically speaking, the stakeholder analysis performed allowed proposal of a general stakeholder analysis framework for infrastructure projects. It can be implemented at each investment phase of the project life cycle, since stakeholders and their motivation may develop and/or change over time, which necessitates development of proper managerial strategies. The findings highlight the opportunities and the challenges faced by stakeholder management. Research limitations/implications The limitation of this study derives from the fact that the sample size was small, which was necessary for an in-depth qualitative research and application of the case study method. The observations were made on a selected case study, within a limited period of time, thus the context of the analysis as well as the stakeholder perception was subject to possible change. The research limitations concern the provisional nature of the information obtained, the cross-sectional nature of the analysis itself, and, finally, the inability to predict all future events. Ultimately, stakeholder mapping was performed for the operational phase of the investment exclusively, while the analysis was limited to identification and classification of the stakeholders, including their relationship with the project. Practical implications The research conclusions provide useful input for future research on development of effective strategies for management of the shareholders that are related to a given infrastructure project, in order to achieve project success. Simultaneously, from a property perspective, the research has contributed to a better understanding of the importance of infrastructure, on the part of real estate stakeholders. Social implications Application of the approach proposed in the study may contribute to early development and implementation of appropriate trust-building processes. The building of relationships between stakeholders enables checks and balances, promotes short- and long-term project benefits, and increases the value of a project. Originality/value The novelty of the research consists in the connection, as part of infrastructure projects, of the theory of consumption values and the concept of an investment cycle with the framework of stakeholder analysis.


2020 ◽  
Vol 12 (24) ◽  
pp. 10557
Author(s):  
Silvia Vilčeková ◽  
Katarína Harčárová ◽  
Andrea Moňoková ◽  
Eva Krídlová Burdová

This article analyzes in detail the impact of wooden houses on the environment using the life cycle assessment (LCA) methodology and at the same time evaluates the indoor environmental quality (IEQ) in these houses. The investigated detached family houses had a wooden structure. The first one had a bearing system made of a wooden frame; other materials were conventional. The second house was built entirely of log wood. Given the high risk of greenhouse gas emissions, the concentration of which in the atmosphere is causing global climate change, the global warming potential (GWP) indicator is crucial. According to results, the family house built entirely of wood and with a biomass boiler significantly reduces CO2 emissions and is therefore considered from the LCA point of view as a more suitable alternative compared to a house with a wooden frame structure. The building materials with the highest share involved in the creation of GWP include concrete structures (38–48%), ceramic roof tiles (33%) and plasterboard (15%). Plasterboard cladding (55%), concrete structures (17–19%), oriented strand board OSB (9–22%), impregnated wooden structures (31–52%) and plastic windows (9%) are the most involved in acidification potential (AP) and eutrophication potential (EP). Plasterboard structures (21%), impregnated wood materials (47.4%), reinforced concrete structures (12%) and mineral wool and roof tiles significantly contribute to the creation of photochemical ozone creation potential (POCP) and ozone depletion potential (ODP). The indoor environmental quality was evaluated through short-term measurements of basic physico-chemical parameters. Since both houses have different characteristics, the aim of this monitoring was to evaluate the actual state of IEQ in selected wooden houses under real conditions. Based on the recorded results, it can be stated that neither presented wooden house, in terms of thermal-humidity microclimate, concentration of CO2 and particulate matter, represents an environment with a negative impact on their occupants. With regards to volatile organic compounds (VOCs), the increased concentrations of xylenes and tetrachlorethylene in the log house were probably caused by the application of impregnation and protective coatings six months before monitoring. In this case, the concentration of tetrachloroethene, which is considered a potential carcinogen, was six times higher than the legislative limit. For VOCs, such as limonene, isobutylene and n-butylacetate, which were found in the wooden frame house, no limits are set. The legislative limits for xylenes and tetrachlorethylene in this house have not been exceeded, and therefore the IEQ cannot yet be considered harmful for health. The presence of all the mentioned VOCs in the interior air of the wooden frame house is more related to the activities of occupants, as this house has been inhabited for several years.


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