scholarly journals Integration of satellite system and Stratospheric Communication Platforms (SCP) for weather observation

2016 ◽  
Author(s):  
◽  
Sihle S. Sibiya

This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.


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.



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.



Aviation ◽  
2018 ◽  
Vol 22 (1) ◽  
pp. 24-30
Author(s):  
Dimov Stojce Ilcev

In this paper is introduced the first proposal for development of Global Aeronautical Distress and Safety System (GADSS) in 1999 by the author of this article. The GADSS is de facto the integration of space (radio and satellite) Communication, Navigation and Surveillance (CNS) with Tracking, Detecting and Search and Rescue (SAR) systems, which have to provide airmen with global communications and locating networks. The GPS, GLONASS and other Global Navigation Satellite Systems (GNSS) provide precise positioning data for vessels, land vehicles and aircraft, but modern CNS demands need for enhanced services and augmentation of GNSS networks. Both networks have to be integrated under an GADSS umbrella with elements capable of being operated by any individual onboard aircraft to ensure prompt distress alert for SAR procedure. The enhanced concept of GADSS is that SAR authorities ashore and ships in the immediate vicinity of the aircraft in distress have to be rapidly alerted via radio and satellite communication systems and to assist in a coordinated SAR operations with the minimum of delay. In 2016, 16 years in delay, the International Civil Aviation Organization (ICAO) has begun its process to amend international standards and recommended practices to align with GADSS concept. This paper will also introduce the necessary networks and equipment, which has to ensure harmonized and enhanced maritime and aeronautical global SAR systems.



1990 ◽  
Vol 66 (5) ◽  
pp. 480-486 ◽  
Author(s):  
W. Moore ◽  
T. Polzin

There is an increasing requirement for a cost-effective means of updating digital base map and natural resources information systems. The Northern Forestry Centre of Forestry Canada is cooperating with Alberta Forestry, Lands and Wildlife and United States agencies to evaluate ER-2 high altitude (i.e., about 20 km) reconnaissance in Alberta. A demonstration flight was arranged on 20 July 1988 to cover flight lines from Waterton Lakes National Park to Lesser Slave Lake, and return (i.e., about 1500 km). The ER-2 platform provides both the high altitude perspective of earth satellite systems and the flexibilities of aircraft. The demonstration flight carried a panoramic camera, two mapping cameras and a digital scanner that were operated simultaneously. This provided rapid, high resolution and stereoscopic coverage of large areas. The savings from improved efficiencies for base map revisions alone, using one mapping camera were greater than the costs of routine ER-2 operations over Alberta. The three other selectable sensors would also permit natural resources information system updates for only the costs of processing, interpretation and data entry. These high altitude capabilities are required for forestry in Canada.



Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1961
Author(s):  
Pham Duy Thanh ◽  
Tran Nhut Khai Hoan ◽  
Hoang Thi Huong Giang ◽  
Insoo Koo

Currently, deploying fixed terrestrial infrastructures is not cost-effective in temporary circumstances, such as natural disasters, hotspots, and so on. Thus, we consider a system of caching-based UAV-assisted communications between multiple ground users (GUs) and a local station (LS). Specifically, a UAV is exploited to cache data from the LS and then serve GUs’ requests to handle the issue of unavailable or damaged links from the LS to the GUs. The UAV can harvest solar energy for its operation. We investigate joint cache scheduling and power allocation schemes by using the non-orthogonal multiple access (NOMA) technique to maximize the long-term downlink rate. Two scenarios for the network are taken into account. In the first, the harvested energy distribution of the GUs is assumed to be known, and we propose a partially observable Markov decision process framework such that the UAV can allocate optimal transmission power for each GU based on proper content caching over each flight period. In the second scenario where the UAV does not know the environment’s dynamics in advance, an actor-critic-based scheme is proposed to achieve a solution by learning with a dynamic environment. Afterwards, the simulation results verify the effectiveness of the proposed methods, compared to baseline approaches.



Eurospace, founded in 1961, is the Organization of the European Space Industry. Its members are 80 major industrial companies, banks and operators from 13 countries in Western Europe. The Association is the mouthpiece of industry to the European Space Agency (E.S.A.), in particular with regard to future European space programmes. In the course of its other promotional activities it has applied and sustained successful efforts to promote a regional communication satellite system serving the African continent.



Author(s):  
S.B. Pichugin

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.



2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hammed O Busari ◽  
Olaosebikan A Fakolujo

The progressively demand on satellite communication systems has consequently resulted in lower frequency bands getting more congested. The usage of frequency band beyond 10 GHz is in focus nowadays as a result of the rapid expansion of radio communication systems. However, Rain is the leading attenuation factor of different communication signal of frequencies beyond 10 GHz. Attenuation due to rain has a significant propagation effect that needs to be carefully considered in satellite communication system network. Rain attenuation predictions and rain rate are essential when planning microwave satellite communication links.  A review of the rain rate integration time and rain attenuation models for microwave and millimeter bands satellite system is presented.  Keywords: Frequency Band, Rain Attenuation, Rain Attenuation Model, Rain Rate, Satellite System



2013 ◽  
Vol 756-759 ◽  
pp. 1204-1209 ◽  
Author(s):  
Wei Zheng ◽  
Bin Li ◽  
Shu Bo Ren ◽  
Jiang Chen ◽  
Jian Jun Wu

In multi-beam satellite systems, Inter-Beam Interference (IBI) has a great effect on system performance. Within range of satellite coverage area, inclined projective multiple beams give rise to elliptic beam projections, resulting in that the distribution of beam projections is different from traditional cellular distribution. In this paper, an Inclined Projection (IP) model is proposed for IBI in OFDMA based GEO satellite communication systems, and corresponding analysis is also included. A comparison of carrier to interference power ratio (C/I) of users at the center of each cell with and without the consideration of IP is made, based on the simulation using different Frequency Reuse (FR) factor. The corresponding conclusions are presented. This research can provide reference for later satellite beam planning.



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