Accession Number : AD0915572

Title :   Adaptive Techniques for Radar Control.

Descriptive Note : Final rept. 31 May 72-31 Jul 73,

Corporate Author : GENERAL ATRONICS CORP PHILADELPHIA PA

Personal Author(s) : Burgess, Lawrence R. ; Zeger, Andrew E.

Report Date : NOV 1973

Pagination or Media Count : 210

Abstract : The significance of this research and development to the Air Force is that slow, low flying aircraft and moving ground vehicles may be detected by employing an adaptively controlled antenna array with an AMTI radar set, conformally mounted in a high performance jet aircraft. Clutter cancellation is achieved through moving the active subaperture of the phased array to the rear of the aircraft with the transmission and reception of each pulse. The control unit which forms these subapertures employes a Guided Accelerated Random Search algorithm to minimize the cancelled clutter power at the output of a two-pulse canceller. Analysis of AMTI radar systems and random scattering properties of the ground led to a computer simulation of the adaptively controlled system described above. Results of this simulation demonstrate that five-foot subapertures consisting of adjacent elements from a linear uniformly spaced phased array can be adaptively controlled to cancel clutter power by better than 40 dB under a wide variety of flight conditions. Degradation in clutter cancellation from this figure due to random element spacing is nominally 20 dB.

Descriptors :   *ADAPTIVE CONTROL SYSTEMS), *AIRCRAFT ANTENNAS), (*PHASED ARRAYS, (*ANTENNA ARRAYS, MOVING TARGET INDICATORS, RADAR ANTENNAS, RADAR CLUTTER, X BAND, TARGET ACQUISITION, INFORMATION THEORY, ALGORITHMS, COMPUTERIZED SIMULATION, ANTENNA APERTURES, SIGNAL PROCESSING, TIME DIVISION MULTIPLEXING, PHASE SHIFT CIRCUITS, RADAR PULSES, RADAR INTERFERENCE, COMPUTER PROGRAMMING, TIME SHARING, SCATTERING.

Subject Categories : Electrical and Electronic Equipment
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE