Abstract: A method and means for converting a high resolution machine monitored phoiode array, comprising staircased linear sets of detectors operating in a time-delay-integration mode, to a low resolution visually monitored array, by delaying the output signal of odd sets in the staircase by the time required to scan one set and integrating the outputs of odd and even sets.

Abstract: A special detector and post-filtering system is provided for a scan conver which processes a TV type video signal from one or more infrared detectors which are vertically sampled at a rate less than the Nyquist rate required for the bandwidth of the detectors.

Abstract: A means for expanding the dynamic range of a forward looking infrared (FL video processing system by inserting an automatic low frequency gain limiting and first post amplifier circuit means at the output of the preamplifiers in each video channel to provide variable pedestal limiting of the low frequency components of the video signal. The automatic low frequency gain limiting and first post amplifier circuit means compresses the pedestal of signals derived from smoke, dust, or fire to arbitrary small levels to preserve sufficient dynamic range for enhancing the high frequency detail signal riding on the pedestals at a display.

Abstract: A reticle brightness control circuit means in a night vision image intenser in which the circuit means utilizes screen current intensity to provide a proportionate amount of current through a reticle light-emitting diode (LED) for controlling the brightness level therefrom as projected on the cathode. When the object image input brightness impinging on the cathode is less than an automatic brightness control limiting level, the screen current limiting level and the reticle LED brightness are directly controlled by the screen current. However, when the object image input brightness goes about the screen current limiting level, the brightness level of the reticle LED is further increased by a decreased feedback voltage from the microchannel plate power supply oscillator (MCP OSC) circuit which provides proportionately more current through the reticle LED wherein the brightness of the reticle image remains commensurate with the input image brightness under all input light levels.

Abstract: A low frequency gain limiting circuit for an AC coupled video processing tem wherein if the low frequency portion of video signals exceed a certain level, the low frequency pedestal is clipped and fed directly to a summing amplifier while simultaneously the low frequency pedestal is differentially compared in a differential amplifier with the original video signals and the resulting short pedestal with the high frequency detail remaining thereon is passed through a high pass filter before application of the high frequency detail only at a second input to the summing amplifier. The addition of the high frequency detail back onto the low frequency pedestal within the summing amplifier provides the gain limited video signal. A video signal comprising low frequency pedestals with amplitudes within the certain level are fed directly through the summing amplifier but no signal will be present at the output of the differential amplifier since both signals cancel.

Abstract: A means of eliminating signal suppression in an A-C coupled video process system by an automatic low frequency gain limiting circuit means. The low frequency gain limiting circuit means comprises a summing amplifier that simultaneously sums the original video pulses and inverted pulses of the low frequency pedestal portion of the video pulses with the detail information removed therefrom. The resulting gain limited output video voltage from the summing amplifier is confined within the linear dynamic range of the video processing system and comprises a compressed pedestal height that nevertheless has all the detail information thereon. The gain limited output video voltage is applied to a display driver.

Abstract: An automatically controlled reference temperature strip for sensing by detors in a thermal imaging system. The signal in each video channel from each related detector is integrated to determine which detector is sensing the hottest target signal and to use the output of this hottest signal video channel for controlling said reference temperature strip.