A coherent, optical signal processor for recognition of specific known targets at extremely high speeds, applying matched-filter techniques. A modified matched filter includes a pair of matched filters that will separately process the high and low spatial frequencies. By properly combining the outputs in a logical AND operation, the target may be interrogated for fine features as well as for correct size and shape. The optical memory bank of matched-filter pairs comprises known diffraction patterns of all resolvable views, in both azimuth and elevation, of the target, thus forming a target recognition comb-filter bank. All views of the recognition bank are simultaneously interrogated optically according to the diffraction pattern of the detected object to determine whether the detected object is the desired target as stored in any of the views in the memory bank.

The radar signals of a vessel navigating on a given course are supplied to a data processing unit connected to an input of a computer. An auxiliary memory is connected to an input of the computer and has stored therein data with respect to land areas adjacent the course of the vessel, and these data are supplied to the computer progressively in accordance with a preset program for comparison with the data supplied by the processing unit. If the comparison indicates that the vessel is at a greater distance from land areas than limits defined by the stored positional data, the processed positional data corresponding to scanned land areas is deleted from the data supplied to a collision avoidance program, so that the processing by this collision avoidance program is made more reliable. After processing by these programs, data are displayed on a display unit.

In the disclosed apparatus, a reference image sensor continuously scans a lmed atlas of images representing terrain being overflown while a second sensor simultaneously scans the terrain. A correlator compares the signal and the reference image sensor describes a course, corresponding to that of the flying body, over the film, in response to control signals based upon the correlation results. The reference image sensor reads only the area of the film around the course.

An area signature detection system arranged to receive an output from a sensor operative in the electromagnetic spectrum, where the output from the sensor is an amplitude varying electrical signal representing the field-of-view beheld by the sensor, and to utilize this high frequency information in such a manner that low frequency scene content, necessary for area correlation processing, can be extracted and effectively utilized. Our invention involves certain highly advantageous techniques for generating area signatures from line scan sensors, and may be applied to cartesian, circular or polar scan formats. In one particular embodiment of our invention, we describe how orthogonally disposed area signatures can be used to generate area correlation tracking signals that can be used in the derivation of appropriate missile guidance commands. Our teachings are also useful in providing line-of-sight stabilization for fire control systems, alignment and position errors for landing and hovering control systems, as well as intrusion detection systems. In the case of a system using a television camera as the sensor, this invention provides a way of obtaining an operator display and system control signals despite the fact that only a single such sensor is used.

A drone aircraft is guided over a desired flight path wherein line map correlation provides x and y offsets from the desired fixed point. The x, y offset signals are used to drive the actuators of the drone's control surfaces and also provide positional information to a monitored display at the control station.