Real time digital scan converter

摘要

A digital scan converter is disclosed for processing the sequence of analog signals supplied by a sector scanning surveillance system to form a signal compatible with television type display devices. The signals supplied by the surveillance system are digitized by an analog-to-digital converter at a rate proportional to the cosine of the azimuthal scan angle that is associated with each analog signal to thereby effect a first portion of the required conversion from the polar coordinate format of the surveillance system to the Cartesian coordinate format of the television display. The digitized signals are stored in a memory so as to permit addressing of a set of stored data that corresponds to one horizontal trace of the television display. The data sets corresponding to successive horizontal lines of the television display are sequentially accessed in accordance with conventional television timing signals and data is serially read from memory and supplied to a digital-to-analog converter at a rate that completes the required polar-to-Cartesian format conversion.