DIGITAL SCAN CONVERTER

摘要

Digital scan converter : A digital scan converter is provided with a memory (1), each cell of which memory containing brightness data for presenting a radar video signal on a raster scan display (2) at a position corresponding with the respective cell; a logical unit (7) for supplying in response to the applied video signals and the brightness data stored in memory (1), new brightness data overwriting that stored in memory (1); an address conversion circuit (10) for converting the addresses established in polar coordinates into addresses expressed in Cartesian coordinates to store the new brightness data in memory (1); and with a circuit (3) connected to the memory (1) for reading out the brightness data and for presenting corresponding video signals on the raster scan display (2). To renew the stored brightness data synchronously with the radar scans such that a prefixed persistence appears on the raster scan display (2), the digital scan converter comprises a control unit (15) for supplying persistence data and azimuth values to process the persistence data and a control code register (19) for storing the persistence data in intervals between successive radar scans. Furthermore, in said interval the latter azimuth values are supplied to the address conversion circuit (10) for generating the addresses of the memory cells and the contents of said memory cells are adapted to the persistence data in the control code register (19) by means of the logical unit (7) communicating with said control code register (19).