Accession Number : AD0776699

Title :   Effects of Airborne Transponder Antenna Lobe Switching on En Route (PCD) and Terminal (BDAS) Beacon Reply Processing.

Descriptive Note : Final rept. on Task C,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Day,Ernest H. ; Pannell,James H.

Report Date : 29 JAN 1974

Pagination or Media Count : 184

Abstract : The comparative performances of switching top and bottom transponder antennas versus the bottom antenna alone, in target detection by ARTS III and by PCD, were investigated in order to determine which of the two antenna configurations is preferable. A variety of military aircraft participated, performing climbouts, orbits, straight and level segments, and descents, in order to expose a wide range of aspect angles to the interrogator. The frequency of occurrence of lost targets, particularly of consecutive lost targets, was found to vary considerably from one aircraft type to another. Analysis of the reduced data provides a reasonable basis, however, for concluding that, to maximize average probability of detection, the bottom antenna is better in the terminal area but switching antennas are better for En Route application. (Modified author abstract)

Descriptors :   *Air traffic control systems, *Aircraft antennas, Transponders, Radar beacons, Tracking, Beacons, Switching, Antenna lobes, Military aircraft

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE