Abstract: A forward looking infrared (FLIR) sensor digital simulation model in which he optics modulation transfer function (MTF) is applied to a set of input scene two dimensional digital data in the spatial domain without transferring the data into the frequency domain. The optics are prior to downsampling detectors. A fast Fourier transform (FFT) is performed on the downsampled two dimensional scene map to convert from the spatial domain to the frequency domain. The effects of MTFs on the other components of the FLIR system are simulated and white noise to the detectors is simulated then the scene map has an inverse FFT performed thereon to convert back to the spatial domain for display to an observer.

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: In the playback of a video disc record employing an FM carrier recording format, a defect compensation system is provided which substitutes delayed video signals for current video signals when a defect is encountered. A phase locked loop including a phase detector and a voltage controlled oscillator is employed in FM detection circuits. A defect detector compares the phase between the oscillator output signal and a signal corresponding to the recovered signal. When the phase difference between these two signals exceeds a certain value, a defect signal is generated to disable the normal signal path of the recovered signal so that the delayed version of the video may be substituted for the current video for the duration of the occurrence of the defect.