Inmarsat Communications System : a Systems Approach
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Fig. 1 System Block Diagram
SSC13-II-2 300 Mbps Downlink Communications from 50kg Class Small Satellites Hirobumi Saito Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS) Naohiko Iwakiri , Atsushi Tomiki, Takahide Mizuno, Hiromi Watanabe, Tomoya Fukami, Osamu Shigeta, Hitoshi Nunomura, Yasuaki Kanda , Kaname Kojima, Takahiro Shinke, and Toshiki Kumazawa Contents 1. Purpose : 320Mbps down link for small sat 2. Onboard segment: high effiency transmitter. small antenna 3. Ground segment : 3.8m S/X band antenna powerful receiver 4. Total simulation : SPW software + link calculation 5. EM test finished. FM maunfacturing now. 6. On-orbit demonstration : 2014 with 50kg sat. Limits of Small Satellites for Earth Observations • Mass Limit(<100kg), Power Limit (<100W) ー Telescope Resolution (5m vs. 0.5m) ー Down link Speed (10Mbps vs. 800Mbps) ・ What is the Bottleneck of Down Link Speed ? - Power ! Down link bit rate VS. satellite mass for low earth orbit. 1.0E+12 ) 1T bps TerraSAR-X Hodoyoshi #4 ( (2014) WorldView1 1.0E+09 EROS-B Formosat2 GeoEye-1 1G Orbview3Kompsat2 ALOS Orbview4 JERS1 EOS-PM1 Ikonos2 Radarsat1 TopSat QuickBird2 ERSEnvisat1 Lewis Landsat ADEOS Spot RazakSat-1 UK-DMC2 MOS 1B MOS 1A Terra IRS-1A,1B,1C UK-DMC1 EROS-A AS1000 AlSat Orbview2 TRMM 1.0E+06 データ伝送速度 1M EarlyBird MicroLabSat Cute-1.7 PRISM TOMS-EP Cute-I Down Link Bit Rate(bps) Link Down Bit 観測衛星の 1.0E+031K 1 10 100 1000 10000 Satellite衛星質量 Mass(kg) (kg) High Speed Down Link for Small Sat • Purpose of This Research: High-speed Down Link System with Low Power Consumption ―Goal 50kg Sat @600km orbit DC power <20W, 320Mbps Small Ground Antenna < 4m System block diagram of high-data-rate downlink. -
Handbookhandbook Mobile-Satellite Service (MSS) Handbook
n International Telecommunication Union Mobile-satellite service (MSS) HandbookHandbook Mobile-satellite service (MSS) Handbook *00000* Edition 2002 Printed in Switzerland Geneva, 2002 ISBN 92-61-09951-3 Radiocommunication Bureau Edition 2002 THE RADIOCOMMUNICATION SECTOR OF ITU The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Inquiries about radiocommunication matters Please contact: ITU Radiocommunication Bureau Place des Nations CH -1211 Geneva 20 Switzerland Telephone: +41 22 730 5800 Fax: +41 22 730 5785 E-mail: [email protected] Web: www.itu.int/itu-r Placing orders for ITU publications Please note that orders cannot be taken over the telephone. They should be sent by fax or e-mail. ITU Sales and Marketing Division Place des Nations CH -1211 Geneva 20 Switzerland Telephone: +41 22 730 6141 English Telephone: +41 22 730 6142 French Telephone: +41 22 730 6143 Spanish Fax: +41 22 730 5194 Telex: 421 000 uit ch Telegram: ITU GENEVE E-mail: [email protected] The Electronic Bookshop of ITU: www.itu.int/publications ITU 2002 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. International Telecommunication Union HandbookHandbook Mobile-satellite service (MSS) Radiocommunication Bureau Edition 2002 - iii - FOREWORD In today’s world, people have become increasingly mobile in both their work and play. -
Development of Earth Station Receiving Antenna and Digital Filter Design Analysis for C-Band VSAT
INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 3, ISSUE 6, JUNE 2014 ISSN 2277-8616 Development of Earth Station Receiving Antenna and Digital Filter Design Analysis for C-Band VSAT Su Mon Aye, Zaw Min Naing, Chaw Myat New, Hla Myo Tun Abstract: This paper describes the performance improvement of C-band VSAT receiving antenna. In this work, the gain and efficiency of C-band VSAT have been evaluated and then the reflector design is developed with the help of ICARA and MATLAB environment. The proposed design meets the good result of antenna gain and efficiency. The typical gain of prime focus parabolic reflector antenna is 30 dB to 40dB. And the efficiency is 60% to 80% with the good antenna design. By comparing with the typical values, the proposed C-band VSAT antenna design is well optimized with gain of 38dB and efficiency of 78%. In this paper, the better design with compromise gain performance of VSAT receiving parabolic antenna using ICARA software tool and the calculation of C-band downlink path loss is also described. The particular prime focus parabolic reflector antenna is applied for this application and gain of antenna, radiation pattern with far field, near field and the optimized antenna efficiency is also developed. The objective of this paper is to design the downlink receiving antenna of VSAT satellite ground segment with excellent gain and overall antenna efficiency. The filter design analysis is base on Kaiser window method and the simulation results are also presented in this paper. Index Terms: prime focus parabolic reflector antenna, satellite, efficiency, gain, path loss, VSAT. -
Positioning Using IRIDIUM Satellite Signals of Opportunity in Weak Signal Environment
electronics Article Positioning Using IRIDIUM Satellite Signals of Opportunity in Weak Signal Environment Zizhong Tan, Honglei Qin, Li Cong * and Chao Zhao School of Electronic and Information Engineering, Beihang University (BUAA), Beijing 100191, China; [email protected] (Z.T.); [email protected] (H.Q.); [email protected] (C.Z.) * Correspondence: [email protected]; Tel.: +86-1381-0629-638 Received: 9 December 2019; Accepted: 25 December 2019; Published: 27 December 2019 Abstract: In order to get rid of the dependence of the navigation and positioning system on the global navigation satellite system (GNSS), radio, television, satellite, and other signals of opportunity (SOPs) can be used to achieve receiver positioning. The space-based SOPs based on satellites offer better coverage and availability than ground-based SOPs. Based on the related research of Iridium SOPs positioning in the open environment, this paper mainly focuses on the occluded environment and studies the Iridium SOPs positioning technique in weak signal environment. A new quadratic square accumulating instantaneous Doppler estimation algorithm (QSA-IDE) is proposed after analysing the orbit and signal characteristics of the Iridium satellite. The new method can improve the ability of the Iridium weak signal Doppler estimation. The theoretical analysis and positioning results based on real signal data show that the positioning based on Iridium SOPs can be realized in a weak signal environment. The research broadens the applicable environment of the Iridium SOPs positioning, thereby improving the availability and continuity of its positioning. Keywords: signals of opportunity positioning; Iridium; weak signal; instantaneous Doppler 1. Introduction The new methods for receiver positioning based on abundant and various frequency signals have emerged in recent years. -
A Review Paper on Microwave Transmission Using Reflector Antennas
International Journal of Scientific & Engineering Research Volume 8, Issue 10, October-2017 ISSN 2229-5518 251 A Review Paper on Microwave Transmission using Reflector Antennas Sandeep Kumar Singh [1],Sumi Kumari[2] Sr. Lecturer, Dept. of ECE, JBIT, Dehradun [1], Asst. Professor, Dept. of ECE, VGIET, Jaipur[2] [email protected][1] [email protected][2] Abstract: The conventional optimization problem of the beamed microwave energy transmission system is considered. The criterion of maximum efficiency of power intercept is parabolic function of distribution on the transmitting antenna. It is shown that under such a condition of amplitude distribution becomes more uniform than as the unconditional optimization. In this case, we can substantially increase the power radiated by the transmitting antenna losing the power intercept no more than 2%. Keywords: Parabolic Reflector Antenna, Radio Relay, Antenna Gain, Cassegrain Feed. I.INTRODUCTION limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can. Microwave radiation is generally defined as that electromagnetic radiation having wavelengths between radio waves and infrared III.ANTENNA radiation. Microwave radiation can be forced to travel in specially designed waveguides. Microwave radiation can be transmitted An antenna (or aerial) is an electrical device which converts through space or through the atmosphere in a microwave beam electric currents into radio waves, and vice versa. It is usually used from a microwave antenna and the microwave energy can be with a radio transmitter or radio receiver. In transmission, a radio collected with a microwave antenna. Microwave antennas are used transmitter applies an oscillating radio frequency electric current to for transmitting and receiving microwave radiation. -
DESIGN of a LOW-COST AUGMENTATION NAVIGATION SYSTEM: the UNITED KINGDOM’S IMMEDIATE ANSWER to the GALILEO BREXIT
DESIGN OF A LOW-COST AUGMENTATION NAVIGATION SYSTEM: THE UNITED KINGDOM’s IMMEDIATE ANSWER TO THE GALILEO BREXIT CONUNDRUM Lawal S Lasisi Satellite Applications and Development, Nigerian Communications Satellite Ltd, Obasanjo Space Center, affiliated to Federal University of Technology, Minna-Nigeria. e-mail: [email protected]; +2348023151587. Chatwin R Chris Engineering and Design, School of Engineering and Informatics, Room 2B07, Shawcross Building, University of Sussex, Falmer, Brighton-UK, BN1 9QT e-mail: [email protected]; +441273678901. ABSTRACT United Kingdom’s Brexit from the European Union implies restricted access to the European Global Navigation Satellite System (GNSS) System - Galileo; with no access to the secured and encrypted signal used for defense and government purposes, which is restricted to European Union (EU) members. To mitigate this issue, the United Kingdom can, as a matter of urgency, launch a payload on a national military Communications Satellite to provide Navigation Overlay Services for the United Kingdom territory, surrounding waters and neighboring ally countries to meet the requirements of: Defense systems, Aviation, Maritime requirements and the effectiveness of Location-based Services for Emergencies and Crisis management etc. This paper describes the design of a navigation overlay service system as a hoisted payload on a national satellite and the required supporting ground infrastructure, highlighting various applications, services and solutions. Keywords: Brexit, Communications Satellite, Defence, European Union (EU), Galileo, GNSS, Military, Precision Point Positioning, SBAS. 1 INTRODUCTION TO GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS) The United States Global Positioning System (GPS) marked the beginning of Global Navigation Satellite Systems (GNSS). After the First World War, radio time signals offered alternative technology for determination of the Greenwich Time line and thus longitude at sea. -
Satellite Communication with the Merge on Television Communication
Special Issue - 2018 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Confcall - 2018 Conference Proceedings Satellite Communication with the Merge on Television Communication Ayyasamy.T Deepika.S Keerthana. K Head of the Department UG Scholar UG Scholar Dept of Aeronautical Dept of Aeronautical Dept of Aeronautical Srinivasan Engineering College, Srinivasan Engineering College, Srinivasan Engineering College, Perambalur-621 212 Perambalur-621 212 Perambalur-621 212 Abstract - In the context of a worldwide communications with run-down batteries, and leftover rocket boosters all network, satellite communications systems are very important. contribute to the count. This online catalogs of satellite has Satellite communications links add capacity to existing almost 26,000 entries! communications capabilities and provide additional alternate Although anything that is in orbit around Earth is technically routings for communications traffic. Satellite links, as one of a satellite, the term "satellite" is typically used to describe a several kinds of long-distance links, interconnect switching centers located strategically around the world. They are part of useful object placed in orbit purposely to perform some the defense communication systems (DCS) network. One specific mission or task. We commonly hear about weather important aspect of the satellite communications network is that satellites, communication satellites and scientific satellite it continues in operation under conditions that sometimes render other methods of communications inoperable. Because of this, II. HELPFUL HINTS satellites make a significant contribution to improved reliability of Navy communications .When satellite television first hit the A.Types of Classification market in the early 1990s, home dishes were expensive metal • Weather satellites help meteorologists predict the units that took up a huge chunk of yard space. -
Factory Radio Communications
0 rf indoor collllllunicafions ___________ Factory Radio Communications Noise and propagation measurements reveal/imitations for UHF/microwave i'ndoor radio communication systems By Theodore S. Rappaport Virginia Polytechnic Institute and State University A glimpse into a typical factory re· any type of tether will require a radio In Japan, spectrum has been set aside veals a high degree of automation has system for control. Optical systems are for 300 mW, 4800 bps indoor radio .entered into the work place. Computer viable, but become inoperative when systems operating in the 400 MHz and driven automated test benches, wired obstructed. Furthermore, radio systems 2450 MHz bands (4). guided robots and PC-controlled drill will be us~ful for quickly and cheaply Accurate characterization of the oper presses are a few examples of the connecting often moved manufacturing ating channel is a mandatory prerequi proliferation of computer technology equipment and computer terminals. Ra site for the development of reliable and automation in manufacturing. The dio will also accommodate reconfig wideband indoor radio systems. Radio boom in automation has created a need urable voice/data communications for channel propagation data from factory for reliable real-time communications in other facets of factory and office building buildings have been· made available for factories. In 1985, the Manufacturing operation and may eventually be used the first time through a research pro Automation Protocol (MAP) networking in homes and offices to provide univer gram sponsored by NSF and Purdue standard was established by manufac- sal digital portable communications (1 ). University. As shown here, it is not . turing leaders to encourage commer Presently, communications· between environmental noise, but rather multi cialization of high data rate communica computers and automated machines are path propagation that limits the capacity tions hardware for use in computer conducted almost exclusively over ca of a radio link. -
Detecting and Locating Electronic Devices Using Their Unintended Electromagnetic Emissions
Scholars' Mine Doctoral Dissertations Student Theses and Dissertations Summer 2013 Detecting and locating electronic devices using their unintended electromagnetic emissions Colin Stagner Follow this and additional works at: https://scholarsmine.mst.edu/doctoral_dissertations Part of the Electrical and Computer Engineering Commons Department: Electrical and Computer Engineering Recommended Citation Stagner, Colin, "Detecting and locating electronic devices using their unintended electromagnetic emissions" (2013). Doctoral Dissertations. 2152. https://scholarsmine.mst.edu/doctoral_dissertations/2152 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. DETECTING AND LOCATING ELECTRONIC DEVICES USING THEIR UNINTENDED ELECTROMAGNETIC EMISSIONS by COLIN BLAKE STAGNER A DISSERTATION Presented to the Faculty of the Graduate School of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in ELECTRICAL & COMPUTER ENGINEERING 2013 Approved by Dr. Steve Grant, Advisor Dr. Daryl Beetner Dr. Kurt Kosbar Dr. Reza Zoughi Dr. Bruce McMillin Copyright 2013 Colin Blake Stagner All Rights Reserved iii ABSTRACT Electronically-initiated explosives can have unintended electromagnetic emis- sions which propagate through walls and sealed containers. These emissions, if prop- erly characterized, enable the prompt and accurate detection of explosive threats. The following dissertation develops and evaluates techniques for detecting and locat- ing common electronic initiators. The unintended emissions of radio receivers and microcontrollers are analyzed. These emissions are low-power radio signals that result from the device's normal operation. -
Overview of Satellite Communications
Overview of Satellite Communications Dick McClure Agenda Background History Introduction to Satcom Technology Ground System Antennas Satellite technology Geosynchronous orbit Antenna coverage patterns 2 COMMUNICATION SATELLITES Uses Example satellite systems 3 Why Satellite Communications? Satellite coverage spans great distances A satellite can directly connect points separated by 1000’s of miles A satellite can broadcast to 1000’s of homes/businesses/military installations simultaneously A satellite can be reached from ground facilities that move Satellites can connect to locations with no infrastructure Satellites adapt easily to changing requirements Some Common SATCOM Systems The INTELSAT system provides globe-spanning TV coverage The Thuraya satellite-based phone system covers all of Saudi Arabia and Egypt DoD Military Communications Satellite System Links field sites with Pentagon and US command centers DirecTV, Echostar Direct-to-home TV XM Radio, Sirius Satellite radio-to-car/home Hughes VSAT (Very Small Aperture Terminal) systems Links GM car dealers, Walmart, Costco, J C Penney, etc. to their accounting centers Common Satellite Orbits LEO (Low Earth Orbit) Close to Earth Photo satellites – 250 miles Iridium – 490 miles Polar Orbit Provides coverage to polar regions (used by Russian satellites) GEO (Geosynchronous Earth Orbit) Angular velocity of the satellite = angular velocity of earth satellite appears to be fixed in space Most widely used since ground antennas need not move Circular orbit Altitude: 22,236 miles Can’t “see” the poles 6 HISTORICAL BACKGROUND People Early satellites Evolution 7 Historical Background: People Arthur C. Clarke Highly successful science fiction author First to define geosynchronous communications satellite concept Published paper in Wireless World , October 1945 Suggested terrestrial point-to-point relays would be made obsolete by satellites Unsure about how satellites would be powered John R. -
Design and Construction of a Cost-Effective Parabolic Satellite Dish Using Available Local Materials
International Journal of Advanced Materials Research Vol. 5, No. 3, 2019, pp. 46-52 http://www.aiscience.org/journal/ijamr ISSN: 2381-6805 (Print); ISSN: 2381-6813 (Online) Design and Construction of a Cost-effective Parabolic Satellite Dish Using Available Local Materials Gbadamosi Ramoni Adewale * Faculty of Science, National Open University of Nigeria, Akure, Nigeria Abstract Communication through satellite is very important at this information age. It can provide complete global coverage. It can be used to send and receive information in remote area where other technology may fail. Communication signals are sent in form of electromagnetic signal which are intercepted by the parabolic dish. The offered high-efficiency and high-gain by the parabolic dish makes it appropriate for direct broadcast satellite reception. However, parabolic dish procurement in developing countries is very expensive. This makes it to be unaffordable to majority of the masses. This paper focuses on design and construction of cheap parabolic satellite dish using local readily available materials. An indigenous technology is exploited to achieve the goal of this work. The paper describes from the scratch, how to design and construct a parabolic dish that can be used to intercept electromagnetic signals from the satellite stationed in the space. The proposed design approach offers a number of advantages such as cost-effectiveness and high simplicity. These are due to the fact that; it can be effectively developed with the easily available materials. Besides, it development demands neither special/long time training nor skill. Thus, both technical and non-technical personnel with minimal training can construct it either for commercial and/or personal use. -
A Feasibility Study of Techniques for Interplanetary Microspacecraft Communications
SSC03-X-8 A Feasibility Study of Techniques for Interplanetary Microspacecraft Communications G. James Wells Dr. Robert E. Zee PhD Candidate Manager, Space Flight Laboratory [email protected] [email protected] (416) 667-7731 (416) 667-7864 Space Flight Laboratory University of Toronto Institute For Aerospace Studies 4925 Dufferin Street, Toronto, Ontario, Canada, M3H 5T6 Abstract. The increasing capabilities and low cost of microsatellites makes them ideal tools for new and advanced space science missions, including their possible use as interplanetary exploration probes. There are many issues that have to be resolved when it comes to employing microspacecraft on such missions. One problem is how to maintain a reliable communications link with the microspacecraft over long, interplanetary distances. Solutions to this problem include either improving the spacecraft transceiver/antenna, using a very large antenna on the ground, or using an array of small antennas on the ground. When looking at the feasibility and costs of these alternatives, it is shown that an array seems to be an ideal solution to the problem. By using several digital signal processing techniques, it should be possible to array a group of commercial-grade amateur ground stations together to synthesize a large-aperture antenna capable of communicating over interplanetary distances while keeping the costs low enough to be sustained by a microspace program. Future hardware experiments will be performed to confirm. Introduction a reasonably wide-bandwidth data link between the ground and a microsatellite at a very high altitude. The increasing capabilities and low cost of Most microsatellites in LEO can maintain a downlink micorsatellite missions make them attractive for data rate of no more than 128 kbps.