IMPROVEMENTS IN WEATHER-RADAR GREY SCALE

Improvements have been made in four aspects of grey scale CAPPI displays for weather radars. In order to improve continuity of the echo patterns across the boundary between adjacent CAPPI elements, the gaps between elements have been reduced. The grey scale equipment is now used in such a way that the no-signal areas of the cathode ray tubes do not produce any luminance. This permits optical integration over the area of the displays. A new circuit provides consistent test patterns with each display for monitoring the luminance steps of the weather echoes and the threshold settings of the grey scale quantizing amplifier. Cams on the deflection coil servos had been used to trigger various components of the equipment and produced irregularities of the display sweep. A new slave servo system, rotating in synchronism with the antenna, now performs this function and has eliminated the irregularities. (Author)