Mark Resources, Inc.

United States of America As Represented by the Secretary of the Air Force

August W Rihaczek

Richard L Mitchell

A non-scanning radar for detecting and tracking multiple moving objects. The transmit antenna continuously illuminates the entire surveillance volume, which can even be omni-directional (hemispherical). Multiple receive antennas are employed, each covering part of the surveillance volume. Receivers are used in combination to measure angles of incidence via interferometry on objects that are resolved in range and Doppler. Very long processing times are used to compensate for the reduced antenna gain compared to any radar that scans. By continuously illuminating the surveillance volume, there is no hard limit to the number of objects that can be simultaneously tracked. The primary application for this technology is detection and tracking of such objects as bullets, artillery projectiles, mortar shells, and rockets, and determining the location of the weapon that fired them. Numerous other applications are also described.

Radar system for continuous tracking of multiple objects

Radar for detecting and tracking short range airborne targets using a non-scanning beam to illuminate the entire search space, and processing the return signals from a plurality of spaced apart receive antennas. Target angle in one plane may be determined by coherent processing of the returns from the plurality of receive antennas. Spacing the receive antennas apart in three dimensions allows determining of two angles, such as azimuth and elevation. Processing of the returns may be coherent or noncoherent, or returns may be processed both coherently and noncoherently. Programmability of the processing algorithms and parameters provide flexibility in applications, as well as flexibility based on such things as the target type and its range. Exemplary applications are disclosed.

Non-scanning radar for detecting and tracking targets

A concept is described for broadening the beam of a phased array radar antenna to provide continuous illumination of all radar targets within the search space, and this beam is compressed upon reception to realize the angular resolution that is possible with the antenna. The process is analogous to pulse compression. The advantages of the long dwell times provided by this concept include superior clutter suppression performance, more accurate tracking of targets, and the ability to analyze the target returns for reliable discrimination, classification and identification. The broad beam also reduces the power seen by an intercept receiver, for increased covert operation. This is all accomplished without any sacrifice in power. Various embodiments are disclosed.

Beam compression radar

This invention involves a method of processing radar returns to form two-dimensional images of targets such as ground vehicles, aircraft, ships, and so forth. Resolution in one dimension is provided by range resolution, and resolution in the other dimension is provided by Doppler resolution. Man-made targets such as ground vehicles or ships consist of scattering centers which are extended smooth plates, long edges, rods and the like. These scattering units typically are so large compared with the radar wavelength that they have a highly lobed backscattering pattern. When the processing time is increased in order to achieve higher Doppler resolution, it is possible to observe over the processing time a full or even more than one sidelobe of the backscattering pattern. Doppler resolution theory shows that under these circumstances the responses of scatterers are smeared out into meaningless background interference, so that image detail is lost. The present invention avoids this problem by analyzing the signal in segments much shorter than used with conventional processing. This is done despite the fact that the required image detail appears to demand long processing times. Processing a scatterer only over the time interval in which it is dominant (it governs the behavior of the phase then) prevents the smearing of scatterers and there is no need to resolve one from another. The result is an improved radar image of actual targets.

Growing community of inventors

Rolling Hills, CA, United States of America

August W Rihaczek