There are over 4,500 aircraft accidents each year with 663 involving fatalities. The U.S. Airforce initiates approximately 200 search missions each year for downed aircraft. On the high seas 350 vessels are lost worldwide each year with approximately 200 deaths occurring on U.S. flag vessels. An effective alerting and locating system using Emergency Locator Transmitters (ELT's) or Emergency Position Indicating Radio Beacons" (EPIRB's) could provide a marked reduction in lives lost from these accidents and conserve Search and Rescue (SAR) resources. Existing means of monitoring for these ELT/EPIRB's consist of limited monitoring by FAA facilities and over flying aircraft (usually on a voluntary basis). The use of satellites to monitor and locate these ELT/EPIRB's is proposed as a solution to the problem. The various methods of satellite monitoring via low orbiting and geostationary type satellites is discussed. Consideration is given to systems using: self knowledge of position; computation of position location using navigation signals; re-transmission of navigation signals; angular direction finding; ranging; and doppler (range rate). The advantage of using synchronous spacecraft (due to the immediate response available) is traded off with the disadvantages of this approach due to the path distance, view angles from high latitudes and mountain terrain and the lack of doppler coupled with the desire for the system to work with the existing ELT/EPIRB's in the field (approximately 150,000). Finally, a system concept is proposed for the near term consisting of near polar orbit satellite(s) at 1000 kilometers altitude to detect and doppler track the existing ELT/EPIRB's. It is envisioned that the system of the future would combine both synchronous and low altitude satellites to obtain the benefits from both approaches.

  • Supplemental Notes:
    • This paper is part of a Bound Set of Five Volumes - Price $20.00. RTCM Assembly Meeting April 26-27-28, 1976, San Diego, California.
  • Corporate Authors:

    Radio Technical Commission for Marine Services

    Washington, DC  United States 
  • Authors:
    • Trudell, B J
    • Willis, H M
    • Chiswell III, B M
  • Publication Date: 1976-4

Media Info

  • Features: References;
  • Pagination: 16 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00148852
  • Record Type: Publication
  • Source Agency: Radio Technical Commission for Marine Services
  • Files: TRIS
  • Created Date: Mar 15 1977 12:00AM