Signal Exploitation and Geolocation
As a world leader in radio frequency signal exploitation and geolocation, the Institute continues to provide advanced systems to government, military, and commercial clients for communications signals intercept, recognition, analysis, direction finding, and geolocation. Platforms include ships, submarines, airplanes, unmanned aerial vehicles, ground vehicles, and fixed sites. The Institute also provides advanced, satellite-based tracking of mobile platforms for worldwide command and control applications. During 1999 and 2000, the Institute's design, development, testing, and manufacturing capabilities for signal exploitation and geolocation systems were certified to ISO 9001 standards by Lloyd's Register of Quality Assurance.
The Institute continues to develop advanced surveillance technologies. This effort includes the development of new algorithms and software to complement Institute advances in small, low-power surveillance equipment and systems. These developments cover microwave backscatter tagging devices, video and audio surveillance systems, and satellite-based remote monitoring equipment.
SwRI is delivering full high-frequency band signal acquisition and direction finding systems to several clients. These wideband systems automatically detect, recognize, and measure the angle-of-arrival of signals appearing in the frequency coverage bands of the equipment group. SwRI's unique design uses parallel multichannel processing for maximum accuracy intercept and DF and automatic suppression of interfering signals. Both automatic and operator-assisted signal analysis systems are provided to meet the signal threat environments posed by conventional and complex communications signals, including direct-sequence spread spectrum, frequency hop, and automatic link establishment.
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Developed using SwRI internal research funds, the high reliability AS-145 HF antennas and the low profile AS-420 VHF/UHF antenna are part of the latest shipboard direction finding systems installed on U.S. Navy and Canadian Navy ships. These systems continue the Institute's 49-year involvement in shipboard radiolocation, signal acquisition, and direction finding research, design, and development. |
As one of the world's leaders in shipboard radiolocation and signal acquisition systems research and development, SwRI is producing the AN/SSQ-120 Transportable Radio DF system for installation on U.S. Navy Ticonderoga Class guided-missile cruisers, Arleigh Burke Class guided-missile destroyers, TAGOS Class open ocean surveillance ships, and the Blue Ridge Class amphibious command ships. The OE-326/SRS-1 DF Antenna Groups continue to be produced for the U.S. Navy's Arleigh Burke Class guided-missile destroyers and Wasp Class amphibious assault ships. Also, SwRI is upgrading the AN/SRD-502 and -503 DF systems currently installed on the Canadian Navy Halifax Class and Iroquois Class frigates. As part of this project, the Institute will integrate all shipboard DF assets into an automated, networked, computer-based system.
The Institute continues to lead the development of satellite beacon tracking instruments based on global positioning systems. The SwRI-developed RS-8 beacon is functionally equivalent to the earlier generation RS-7, with new features that include reduced volume, weight, and power consumption. Capabilities are enhanced by new firmware used to make the RS-8 "smarter" by creating a satellite pass table that tells the RS-8 when it can communicate with a low-earth-orbit satellite overhead, no matter where the RS-8 may be located.
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SwRI-developed software is used to predict geolocation performance against radio signals such as those used by the maritime community for search and rescue (SAR). Areas where SAR transmissions can be heard at only one land-based receiving site are shown in gray. Where multiple sites receive the same SAR signal, achievable geolocation performance, expressed as an area of containment, is indicated in color. |
Combining a wide selection of available radio frequency propagation models with SwRI-developed software for netting of direction finding (DF) and time-difference-of-arrival (TDOA) systems, Institute engineers can predict coverage and geolocation performance for any DF and TDOA net geometry before the system is deployed.
The Institute offers unique engineering services to verify compliance in meeting the Federal Communications Commission mandate for locating wireless emergency 9-1-1 callers who are unable to determine their location. SwRI is working with wireless carriers to select location technologies for their service areas. Applying extensive expertise in developing geolocation systems, Institute staff provide accurate predictions of location system performance using computer simulations. These accuracy assessments permit the wireless carrier to make an informed decision regarding the various handset or network-based location technologies. Also, the Institute is working with wireless carriers and emergency response centers to ensure that carriers remain in compliance after the location systems are deployed. Guided by computer predictions of performance, staff can focus field trials in critical areas, thereby providing a highly cost-effective validation.
| Copyright© 2001 by Southwest Research Institute. All rights reserved under U.S. Copyright Law and International Conventions. No part of this publication may be reproduced in any form or by any means, electronic or mechanical, including photocopying, without permission in writing from the publisher. All inquiries should be addressed to Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510, phone (210) 522-2257, fax (210) 522-3547. |
