Abstract: Four radiant energy detectors are arranged in a common plane in a substantially square configuration with each detector occupying a separate quadrant. Infra-red energy received from a target is focused onto the detectors by means of a lens, there being a chopper positioned between the lens and the detectors to chop the radiant energy in a periodic fashion. The outputs of diagonally opposite pairs of detectors are each directly fed to a separate differencing amplifier, where difference signals are generated. These difference signals are then added together and subtracted from each other in separate circuits in a predetermined manner to produce a first signal representing the departure in azimuth of the target from a reference axis running through the center of the detector array, and a second signal representing the departure in elevation of the target from this same axis.

Abstract: A radiant energy detection system includes a first and second pairs of radiation detectors, the detectors of each pair facing in opposite directions to each other, the first and second pairs being positioned in a mutually orthogonal relationship. The detectors may be joined together in a cube structure which is fixedly mounted on a support. A chopper mechanism is mounted over the detectors; this chopper mechanism being supported on a motor shaft for rotatable drive thereby around the detector assembly. The signals arriving at the detectors from a radiant energy source are chopped by the chopper to produce a periodically varying output signal from each of the detectors.

Abstract: A single channel transmission and recording system for a scanner having a multi-channel array of dectors having a single delta modulator in the transmission unit and a single delta demodulator in the receiving unit. A plurality of analog signals, such as video signals sensed by infrared detectors, are each fed to an associated channel having an associated switch circuit. A suitable switch logic generator samples the switches in successive ascending order and subsequently in successive descending order. The sampled analog signals of each channel are fed to a signal delta modulator which converts them to a serial train of digital signals. A synchronizing code generator generates a synchronizing code word which is transmitted with the serial train of digital signals to a receiving station where the serial train of digital signals is reconverted to an analog signal similar to the sampled analog signals for display on a suitable device such as a cathode ray tube.