African satellite communication systems and their implications

1984 ◽  
Vol 312 (1519) ◽  
pp. 33-38
Keyword(s):  
Communication Systems ◽  
Western Europe ◽  
Satellite Communication ◽  
European Space Agency ◽  
Satellite System ◽  
African Continent ◽  
Communication Satellite ◽  
Industrial Companies ◽  
Space Industry ◽  
Space Agency

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.

Simulation analysis and performance of a feasible GNSS system with multi-beam antennas deployment operating in Galileo frequency bands

2012 ◽  
Vol 4 (5) ◽  
pp. 537-543
Author(s):  
Constantinos T. Angelis
Keyword(s):  
Simulation Analysis ◽  
European Space Agency ◽  
Satellite System ◽  
Access Time ◽  
Maximum Efficiency ◽  
Satellite Systems ◽  
Space Agency ◽  
Simulation Results ◽  
And Performance ◽  
Global Navigation Satellite

New Global Navigation Satellite System (GNSS) systems under development, such as Galileo, are very promising for future global positioning-based applications. A vast research is undergoing a final stage of implementation in order to fulfill the primary purpose of European Space Agency for developing and then sustaining of 30 (27 + 3 spares) Galileo satellites in orbit. This article presents simulation results for a realistic deployment of multibeam antennas, with a new modified theoretical pattern, in GNSS Satellite Systems. The proposed multibeam antennas use 61-spot beams for maximum efficiency in terms of satellite coverage and accessing high quality of service. In order to prove the reliability and feasibility of this work, various simulations were conducted using the upcoming Galileo system as a platform taking into consideration real-world conditions. Gain analysis versus elevation, Bit Error Rate (BER) and access time simulation results show that the viability of the proposed multibeam antenna deployment is established.

Proposal of Establishing an Asian Space Agency

2021 ◽  
pp. 180-197
Keyword(s):  
International Cooperation ◽  
European Space Agency ◽  
Space Policy ◽  
Space Application ◽  
Asian Countries ◽  
Research Cooperation ◽  
Space Industry ◽  
Science Technology ◽  
Space Agency ◽  
The Creation

This chapter describes the author's proposal on the necessity of Establishing an Asian Space Agency (ASA). The establishment of the ASA will promote the international cooperation among Asian countries in space exploitation, research and technology, as well as their space application and developments, much like the European Space Agency in Paris. It is desirable and necessary for us to establish ASA in order to promote cooperation in space policy, law, science, technology, and industry among Asian countries. The creation of an ASA would lead to a strengthening of the cooperation deemed essential by the Asian community towards joint undertakings in space and would act as a catalyst for the efforts on space exploitation and allow resources, technology, manpower, and finances to be centrally managed in an independent fashion to the benefit of Asian countries. It is desirable and necessary for us to establish the ASA in order to develop the space industry to strengthen friendly relations and to promote research cooperation among Asian countries.

Prospects of the EPS GRAS Mission For Operational Atmospheric Applications

2008 ◽  
Vol 89 (12) ◽  
pp. 1863-1876 ◽  
Author(s):  
Juha-Pekka Luntama ◽  
Gottfried Kirchengast ◽  
Michael Borsche ◽  
Ulrich Foelsche ◽  
Andrea Steiner ◽  
...  
Keyword(s):  
Global Navigation Satellite System ◽  
Weather Prediction ◽  
European Space Agency ◽  
Satellite System ◽  
Navigation Satellite ◽  
Navigation Data ◽  
Space Agency ◽  
Atmospheric Sounding ◽  
Global Navigation Satellite ◽  
Globally Distributed

Global Navigation Satellite System (GNSS) Receiver for Atmospheric Sounding (GRAS) is a radio occupation instrument especially designed and built for operational meteorological missions. GRAS has been developed by the European Space Agency (ESA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) in the framework of the EUMETSAT Polar System (EPS). The GRAS instrument is already flying on board the first MetOp satellite (.MetOp-A) that was launched in October 2006. It will also be on board two other MetOp satellites (MetOp-B and MetOp-C) that will successively cover the total EPS mission lifetime of over 14 yr. GRAS provides daily about 600 globally distributed occultation measurements and the GRAS data products are disseminated to the users in near-real time (NRT) so that they can be assimilated into numerical weather prediction (NWP) systems. All GRAS data and products are permanently archived and made available to the users for climate applications and scientific research through the EUMETSAT Unified Meteorological Archive and Retrieval Facility (U-MARF) and the GRAS Meteorology Satellite Application Facility (SAF) Archive and Retrieval Facility (GARF). The GRAS navigation data can be used in space weather applications.

scholarly journals The Airborne Demonstrator for the Direct-Detection Doppler Wind Lidar ALADIN on ADM-Aeolus. Part II: Simulations and Rayleigh Receiver Radiometric Performance

2009 ◽  
Vol 26 (12) ◽  
pp. 2516-2530 ◽  
Author(s):  
Ulrike Paffrath ◽  
Christian Lemmerz ◽  
Oliver Reitebuch ◽  
Benjamin Witschas ◽  
Ines Nikolaus ◽  
...  
Keyword(s):  
Direct Detection ◽  
European Space Agency ◽  
Satellite System ◽  
Satellite Mission ◽  
Backscatter Signal ◽  
Space Agency ◽  
Expected Performance ◽  
Wind Lidar ◽  
Doppler Wind Lidar ◽  
Signal Intensities

Abstract In the frame of the Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) satellite mission by the European Space Agency (ESA), a prototype of a direct-detection Doppler wind lidar was developed to measure wind from ground and aircraft at 355 nm. Wind is measured from aerosol backscatter signal with a Fizeau interferometer and from molecular backscatter signal with a Fabry–Perot interferometer. The aim of this study is to validate the satellite instrument before launch, improve the retrieval algorithms, and consolidate the expected performance. The detected backscatter signal intensities determine the instrument wind measurement performance among other factors, such as accuracy of the calibration and stability of the optical alignment. Results of measurements and simulations for a ground-based instrument are compared, analyzed, and discussed. The simulated atmospheric aerosol models were validated by use of an additional backscatter lidar. The measured Rayleigh backscatter signals of the wind lidar prototype up to an altitude of 17 km are compared to simulations and show a good agreement by a factor better than 2, including the analyses of different error sources. First analyses of the signal at the Mie receiver from high cirrus clouds are presented. In addition, the simulations of the Rayleigh signal intensities of the Atmospheric Laser Doppler Instrument (ALADIN) Airborne Demonstrator (A2D) instrument on ground and aircraft were compared to simulations of the satellite system. The satellite signal intensities above 11.5 km are larger than those from the A2D ground-based instrument and always smaller than those from the aircraft for all altitudes.

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

2016 ◽  
Author(s):  
◽  
Sihle S. Sibiya
Keyword(s):  
High Altitude ◽  
Communication Systems ◽  
Satellite Communication ◽  
Meteorological Data ◽  
Cost Effective ◽  
Satellite System ◽  
Satellite Systems ◽  
Observation Area ◽  
Solar Powered ◽  
Weather Observation

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.

scholarly journals Preliminary Results of an Astri/UWM EGNSS Receiver Antenna Calibration Facility

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4639
Author(s):  
Karol Dawidowicz ◽  
Jacek Rapiński ◽  
Michał Śmieja ◽  
Paweł Wielgosz ◽  
Dawid Kwaśniak ◽  
...  
Keyword(s):  
European Space Agency ◽  
Arm Movement ◽  
Calibration Procedure ◽  
Satellite System ◽  
Robot Arm ◽  
Time Zone ◽  
Mean Values ◽  
Space Agency ◽  
Global Navigation Satellite ◽  
Antenna Calibration

In 2019, the University of Warmia and Mazury in Olsztyn, in cooperation with Astri Polska, started a European Space Agency (ESA) project. The purpose of the project is the development and implementation of a field calibration procedure for a multi-frequency and multi-system global navigation satellite system (GNSS). The methodology and algorithms proposed in the project are inspired by the “Hannover” concept of absolute field receiver antenna calibration; however, some innovations are introduced. In our approach, the antenna rotation point is close to the nominal mean phase center (MPC) of the antenna, although it does not coincide with it. Additionally, a National Marine Electronics Association local time zone (NMEA ZDA) message is used to synchronize the robot with the GNSS time. We also propose some modifications in robot arm movement scenarios. Our first test results demonstrate consistent performance for the calibration strategy and calibration procedure. For the global positioning system (GPS) L1 frequency, the calibration results show good agreement with the IGS-type mean values. For high satellite elevations (20°–90°), the differences do not exceed 1.5 mm. For low elevation angles (0°–20°), the consistency of the results is worse and the differences exceed a 3 mm level in some cases.

scholarly journals Atmospheric influence on a laser beam observed on the OICETS – ARTEMIS communication demonstration link

2010 ◽  
Vol 3 (5) ◽  
pp. 1233-1239 ◽  
Author(s):  
A. Löscher
Keyword(s):  
Laser Beam ◽  
Atmospheric Turbulence ◽  
Satellite Communication ◽  
European Space Agency ◽  
Atmospheric Science ◽  
Satellite Link ◽  
The Earth ◽  
Space Agency ◽  
Japan Aerospace Exploration Agency ◽  
Specific Experiment

Abstract. In 2006 bi-directional optical inter-satellite communication experiments were conducted between the Japan Aerospace Exploration Agency (JAXA) Optical Inter-orbit Communications Engineering Test Satellite (OICETS) and the European Space Agency (ESA) multi-purpose telecommunications and technology demonstration satellite (Advanced Relay and Technology MISsion) ARTEMIS. On 5 April 2006, an experiment was successfully carried out by maintaining the inter-satellite link during OICETS's setting behind the Earth limb until the signal was lost. This setup resembles an occultation observation where the influence of Earth's atmosphere is evident in the power fluctuations recorded at ARTEMIS's (and OICETS's) receiver. These fluctuations do not exist or are at a low level at a link path above the atmosphere and steadily increase as OICETS sets behind the horizon until the tracking of the signal is lost. This specific experiment was performed only once since atmospheric science was not the goal of this demonstration. Nevertheless, this kind of data, if available more frequently in future, can help to study atmospheric turbulence and validate models. The data present here were recorded at ARTEMIS.

scholarly journals Rain Attenuation Prediction Models in Microwave and Millimeter Bands for Satellite Communication System: A Review

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hammed O Busari ◽  
Olaosebikan A Fakolujo
Keyword(s):  
Frequency Band ◽  
Communication System ◽  
Communication Systems ◽  
Satellite Communication ◽  
Rain Rate ◽  
Satellite System ◽  
Rain Attenuation ◽  
Rapid Expansion ◽  
Satellite Communication System ◽  
Communication Signal

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

System Modeling and Precoding Design for Multi-beam Dual-polarized Satellite MIMO System

2019 ◽  
Vol 13 (4) ◽  
pp. 374-381
Author(s):  
Tao Kai ◽  
Sun Xiaoyun ◽  
Wang Yang ◽  
Jingchun Li
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Channel Model ◽  
Transmission Rate ◽  
Mimo System ◽  
System Modeling ◽  
Satellite Communications ◽  
Satellite System ◽  
System Capacity ◽  
Dual Polarized

Background: As the multimedia service develops and the transmission rate in terrestrial communication systems increases rapidly, satellite communication needs to improve the transmission rate and throughput. Multiple Input Multiple Output (MIMO) techniques can increase the system capacity significantly by introducing the space dimension, as the system bandwidth remains the same. Therefore, utilization of MIMO for satellite communications to increase the capacity is an important research topic. So MIMO techniques for multibeam satellite communications are researched in the dissertation. Objective: The goal of this work is improving the capacity of the satellite system. Multi-beam and dual-polarized technologies are applied to a satellite system to improve the capacity further. Methods: In this paper, we first introduce a multi-beam dual-polarized satellite multi-put and multiout (MBDP-S-MIMO) system which combines the full frequency multiplexing and dual-polarization technologies. Then the system model and channel model are first constructed. At last, to improve the capacity further, BD and BD-ZF precoding algorithms are applied to MBDP-S-MIMO and their performance is verified by simulation. Results: Simulation results show the performance of the BD precoding algorithm gets better with the growth of the XPD at the receiver and is almost not affected by the growth of the channel polarization correlation coefficient. In addition, with the growth of the users’ speed, the performance becomes worse. Conclusion: The multi-beam dual-polarized satellite MIMO system has high capacity, and it has certain application prospects for satellite communication.

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