This invention relates to a method and apparatus for displaying the presence or absence of signal activity. Signal activity is stored at a slow rate optimum for the receiver and then read out at a fast rate (above that of the flicker rate), so that the operator has a visually constant display output and fast phosphors can be used with high light outputs. The display is in the form of a "falling raster" in which successive stored sweeps are vertically ordered; the newest at the top, the oldest at the bottom. In sequence, the oldest sweep is purged from storage and the newest activity added in a spatially ordered manner to the raster.
A record and reproduction system for a forward-looking radar. Video, blang, horizontal and vertical deflection signals are recorded directly from a radar receiver on a single wideband tape track. A composite signal of the radar receiver information is formed by pulse width modulating the deflection signals which are time multiplexed into the blanking interval preceding the video signal. On playback, the composite signal is demultiplexed and the video and deflection signals recovered for direct radar display of in-flight data.
