| 摘要 |
<p>Analog video information with a wide range of radar characteristics is converted by a digital scan converter into a standard TV format. The analog video information is converted to digital PPI data and stored in a buffer. The digital PPI data is consecutively integrated on a pulse to pulse basis to eliminate noise. The digital PPI data is then stored in an image memory (RAM). The polar coordinates of each digital PPI data sample are converted to an address of equivalent X, Y coordinates wherein each point along a TV line is an X coordinate and each TV line is a Y coordinate. This address defines the location at which the data is stored in the RAM. Each address of X, Y coordinates uniquely defines a cell in the RAM which is three bits deep, describing eight intensity levels. Data is read from the image memory in time sequence with a TV synchronization signal for display on a TV monitor. During TV memory cycles, an N element word is read from the RAM to drive the video output circuits, processed through a programmable read-only memory programmed in accordance with a randomized decay function and written back into the same memory address. During radar cycles, an N bit word is read from the image memory and one bit in each word is updated in accordance with the new radar data.</p> |
