SUSCEPTIBILITY TESTING OF COMMERCIAL GPS

SUSCEPTIBILITY TESTING OF COMMERCIAL GPS Commercial GPS units are quickly proliferating on both civilian and military vessels plying the world's waterways. As a result, our dependency on commercial GPS technology is also proliferating, and increasing the possibility of electromagnetic interference (EMI) and damage to these units. An on-going investigation by the United States Navy (USN) and United States Coast Guard (USCG) has determined that many commercially available GPS that employ active antenna electronics are susceptible to high power radar emissions. Ironically, the use of higher power radars on the world's military vessels is also increasing, furthering the possibility of interference and damage. At this time, separation distances required to avoid interference and potential antenna damage can be in excess of one half nautical mile. The USCG has received numerous reports from commercial maritime operators, both domestically and internationally, concerning GPS antenna damage. The USCG Maritime Liaison Office (MARLO) Bahrain has published an internationally released Advisory Bulletin 02-01 titled Global Positioning System (GPS) Interference Advisory based on these reports. The United States Naval Surface Warfare Center Dahlgren Division (NSWCDD) located in Dahlgren, Virginia, in support of the USCG is currently planning high power radar susceptibility testing of commercially available GPS that employ active antenna electronics. This testing will be used to determine the power level, duty cycle, modulations, and frequencies that will cause the performance of GPS to degrade, lose satellite lock, or become permanently damaged. The GPS susceptibilities will be recorded for out-of-band emissions. These GPS susceptibility and vulnerability test results will be used to form the foundation of recommendations made to the International Electro-technical Commission (IEC) for changing international performance standards of commercial GPS. The goal is to ensure that the end users of commercial GPS products can operate at reasonable separation distances from offending ships or shore based emitters without the potential of electromagnetic interference and damage. Identifying and adjusting the performance standards for GPS manufacturers would, in effect, change the design standards for commercial GPS that employ active antenna electronics. Hardening these GPS would increase their ability to perform satisfactorily and survive in the presence of the most stressing of electromagnetic environments of the world's various ships. NSWCDD invites commercial GPS manufacturers to participate in this process. The larger the test sample size, the more successful this effort will be. Participating manufacturers will have the opportunity to review the test plan prior to the test and provide technical feedback, increasing the effective value of the effort. Participating manufacturers will be required to provide two GPS antennas that incorporate active electronics and one receiver for each antenna model to be tested. NSWCDD will not be liable for any damages to the provided equipment. Equipment provided by manufacturers can be returned if prepaid shipping is provided by the manufacturer, otherwise GPS units will become the property of the US Government and will be disposed of in accordance with Federal Regulations. Each participant will be required to execute a Bailment Agreement with NSWCDD formally agreeing to the terms and conditions stated herein. As part of the Bailment Agreement NSWCDD will require manufacturers to conduct a failure diagnosis on any of their units damaged during the test to determine failure points. Results of that analysis will be provided to the NSWCDD POC for assessment. Component failure analysis results could be used by semiconductor manufacturers to design more robust, EMI hardened integrated electronic circuit chips. Depending on the response from manufacturers, a predetermined selection process may be necessary to limit the total number of systems tested due to time and costs. GPS units that meet IEC 61108-1 Maritime navigation and radio-communication equipment and system second edition 2003-07 or equivalent will be given first priority. GPS handheld recreational units will not be considered. Manufacturers who do participate will receive a final report, which will include generic test results, graphs, and test data. All specific individual manufacturers test data will be kept confidential by use of a key code assigned to each unit tested. This test event is currently planned for December 2004, and manufacturers that wish to participate must execute a Bailment Agreement on or before November 1, 2004. Upon completion of the Bailment Agreement the manufacturer will be provided with a Key Code and shipping instructions. Units must be received by NSWCDD on or before December 1, 2004. If you are a commercial GPS manufacturer or GPS antenna manufacturer and would like to participate, please contact the NSWCDD POC listed below. POC : Code J54 PHONE: +1 (555) 000-0000 FAX: +1 (555) 000-0000 E-MAIL: contact@example.gov MAILING ADDRESS: COMMANDER DAHLGREN DIVISION ATTN, J54 NAVAL SURFACE WARFARE CENTER, DAHLGREN DIVISION 17320 DAHLGREN ROAD BLDG 150 DAHLGREN, VA 22448-5100