Raytheon Company

Nathan Freedman

Wayne H Keene

Albert V Jelalian

Roy E Byington

David Garvin Armstrong

Fritz A Gross

Neil F Lacey

William J Wilson

A radar performance monitor (RPM) receives a transmitted radar signal from a radar system being monitored and couples the signal to a recirculating loop comprising a SAW delay line in order to produce a series of simulated radar return signals of equal amplitude and by using the same frequency as the received radar signal providing the frequency falls within a predetermined bandwidth of the SAW delay line. The simulated radar return signals are displayed at the radar system and used to evaluate the operation and calibration of a transmitter and the sensitivity and calibration of a transmitter and the sensitivity and calibration of a receiver in the radar system. The radar performance monitor is actuated at the option of a radar operator.

Recirculating delay line radar performance monitor

A laser is provided for generating a beam of continuous wave (CW) electromagnetic energy having a nominal frequency and amplitude. The frequency of the CW beam is modulated (FM) from the nominal frequency. The amplitude of the frequency modulated beam is modulated (AM) from the nominal amplitude to produce an amplitude and frequency modulated continuous wave (AM-FM CW) beam of energy. A local oscillator beam is produced from the frequency modulated CW beam. The AM-FM CW beam is directed for reflection by a target. The target-reflected return portions of the AM-FM CW beam are combined with the frequency modulated local oscillator beam to produce a beat frequency signal which is subsequently detected, the beat frequency signal having a frequency component representative of the range of the target. Such arrangement, when implemented in a radar system, provides such radar system with accurate target range measurements unambiguous over large ranges. Further, such AM-FM CW signal provides high resolution between target-reflected return signals of such AM-FM CW signal and returns from near-field atmospheric clutter.

AM-FM laser

A laser radar system wherein a beam of continuous wave (CW) electromagnetic energy is generated with frequency modulation (FM) and amplitude modulation (AM) being imposed thereon to produce an amplitude and frequency modulated, continuous wave beam of energy. The AM-FM CW beam is transmitted toward a selected target, portions of the transmitted beam being reflected by the target and received along with portions of the transmitted beam reflected by unselected targets and atmospheric clutter. A first signal is produced in response to the frequency modulation on the received beam portions reflected by the selected target, such first signal representing the approximate range of the selected target and substantially resolving the selected target from unselected targets and atmospheric clutter and having a relatively long ambiguous range interval. A second signal is produced in response to the amplitude modulation on the received beam portions reflected by the selected target, the second signal representing the accurate range of the selected target within a relatively short ambiguous range interval. The second signal provides poor resolution between the selected target and the unselected targets and atmospheric clutter. The first and second signals are combined to produce an output signal having the relatively high resolution and long ambiguous range interval of the first signal and providing the accurate selected target range measurement of the second signal.

AM-FM laser radar

A code generation and receiving system for a large bandwidth Doppler tolerant signal for use by communication and radar systems includes a set of delay lines for producing discrete phase shifts on a carrier signal. One delay line with relatively large delays between taps thereon produces a set of quadratic phase shifts approximating a frequency sweep. A second delay line with relatively small delays between taps thereon produces a binary phase code.

Hybrid pulse compression system

A voice-modulated transponder system comprising an interrogator and a light-weight transponder. In the described embodiment, the interrogator is airborne and the transponder is located on the ground. The interrogator can locate the position of the transponder and simultaneously therewith two-way voice communication between the interrogator and transponder is possible.

Growing community of inventors

West Newton, MA, United States of America

Nathan Freedman