Accession Number : ADD006451

Title :   Radar Receiver for Detecting Coded Information Buried in Radar Echoes.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Okrent,Jasper J

Report Date : 15 May 1979

Pagination or Media Count : 7

Abstract : An IFF radar system having a processor for analyzing radar reflections to determine if the reflections were artificially modulated by a cooperative target in accordance with some predetermined code. The processor ignores modulations in the radar reflections due to Doppler shifts. The amplitude of the detected target return is sampled and held in the radar receiver. The resulting signal is fed to the processor. The signal is then (half or full wave) rectified, the DC removed and then correlated in a multiplier with the predetermined coded signal, which is generated in the processor. The output of the multiplier is then integrated. If there has been a modulation of the reflected energy exactly in accordance with the predetermined code, then the output of the integrator will increase to a point detected by a threshold device. Although there will be modulations in the received signal due to the Doppler effect, the rate and phase of these modulations will be such that the time integral over a given time will be small or nonexistent. (Author)

Descriptors :   *Patents, *Radar receivers, IFF systems, Doppler radar

Subject Categories : Active & Passive Radar Detection & Equipment
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE