Accession Number : ADD017318

Title :   Jammer Reference Target Measurement System.

Descriptive Note : Patent, Filed 18 Mar 81, patented 25 Oct 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Lewis, Bernard L ; Kretschmer, Frank F , Jr

Report Date : 25 Oct 1994

Pagination or Media Count : 15

Abstract : A system for cancelling jammer signals entering the mainlobe of a monopulse radar and providing target locations with respect to the jammer position comprising for a sequential lobing embodiment: measuring the angular position of the jammer in the radar's mainlobe via the use of monopulse sum and difference signals, pointing the radar antenna so that the jammer is positioned within the 3 dB points of the mainlobe of the monopulse antenna, converting the sum and difference echo signals received with the antenna in this position from the next radar transmission into a second set sum and difference signals, applying this second set of sum and second set of difference signals to the inputs of an adaptive canceller to cancel the jamming signal therein and storing these signals in time sequential order, changing the orientation of the radar antenna by a small arbitrary elevation angle, converting the sum and difference echo signals received with the antenna in this new position from a third radar transmission into a third set of sum and difference signals, applying this third set of sum signals and third set of difference signals in reverse order relative to the second set of signals to the inputs of an adaptive canceller to cancel the jamming signal therein, reading out the adaptively cancelled stored echo signals from the second radar transmission into one input of a divider in time coincidence with the application of the adaptively cancelled echo signals from the same targets from the third radar transmission to the other input of the divider to obtain ratio signals proportional to the elevation angle separating the individual targets from the jammer.

Descriptors :   *TARGET DETECTION, *RADAR JAMMING, *PATENTS, INPUT, ANGLES, POSITION(LOCATION), RATIOS, RADAR, TARGETS, SEQUENCES, TIME, ECHOES, SIGNALS, ANTENNAS, ADAPTIVE SYSTEMS, JAMMING, MONOPULSE RADAR, NOISE, ELEVATION, RADAR ANTENNAS, CANCELLATION, RADAR TRANSMITTERS, ANTENNA LOBES, COINCIDENCE COUNTING, SEPARATORS

Subject Categories : Radar Countermeasures
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE