Accession Number : ADA321599

Title :   Beacon Radar and TCAS Reply Rates: Airborne Measurements in the 1090 MHz Band.

Descriptive Note : Project rept.,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Harman, William H. ; Brennan, Martin J.

PDF Url : ADA321599

Report Date : 29 JAN 1997

Pagination or Media Count : 40

Abstract : The Federal Aviation Administration (FAA) is in the process of developing Automatic Dependent Surveillance Broadcast (ADS-B) techniques. In one candidate system, GPS-Squitter, each aircraft periodically broadcasts messages, called 'squitters,' that report the aircraft's identification, position, and velocity. The position and velocity information may be obtained from the Global Positioning System (GPS). Reception of squitters can be used for several purposes, including surveillance of airborne aircraft by a ground station, surveillance of aircraft on the airport surface, and air-to-air surveillance. In developing the new system, it is necessary to know the rates of existing signal transmissions in the 1030 and 1090MHz frequency bands, which are the beacon-radar and TCAS interrogation and reply channels. The GPS-Squitter would be transmitted in the 1090MHz band, like a reply. A key issue is the possibility of interference to squitter reception from existing signals in the 1090MHz band. To validate initial calculations, Lincoln Laboratory is making direct measurements of the rates of existing transmissions in both hands. This report describes the measurements in the 1090 MHz band. An instrumented aircraft was flown from Boston to New York and other locations while recording 1090 MHz receptions. The data has been processed to show the reception rates for Mode S replies and, separately, ATCRBS replies. The results have been plotted to show received rates vs. time and location. Results of this kind are given for Boston, New York, Philadelphia, Atlanta, Dallas, Lakeland FL, and the Los Angeles Basin. The results have also been used to support analyses of GPS-Squitter performance under current conditions and projected into the future.

Descriptors :   *AIR TRAFFIC CONTROL SYSTEMS, *IFF SYSTEMS, AIRBORNE, RADAR TRACKING, GLOBAL POSITIONING SYSTEM, AVIATION SAFETY, COLLISION AVOIDANCE, RADAR BEACONS.

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE