GB1315505A - Radar installations - Google Patents

Abstract

1315505 Radar LICENTIA PATENTVERWALTUNGS-GmbH 14 Aug 1970 [29 Nov 1969] 39228/70 Heading H4D A radar installation has at least two independently operated overlapping primary radars each combined with a secondary radar arranged to provide a mosaic display on a common display screen, means for selecting desired targets, and switching means actuated by whichever display zone contains a selected target, for selecting information from that secondary radar which is combined with the primary radar whose information is displayed in the said zone. Two primary radars produce polar co-ordinate PPI displays on storage tubes in units 11, 12. These displays are synchronously scanned by a TV raster produced by generator 4. The two readout video signals are passed to a switch in unit 24 which is controlled to select signals from the radar chosen to provide the display for that zone of the mosaic display which is being scanned at that instant. The switch is controlled by a comparator which is fed with the line and field deflection voltages and information from a data store which defines the boundary between the two zones of the mosaic display. A joy-stick or light pistol control 3J positions a target selection marker on the TV display (3). The bright-up pulse U sym b for the marker passes to two AND gates 38, 39 which are also supplied with complementary signals U s1 and U s1 inv which indicate the position of the video selection switch of unit 24. The gate outputs define the bi-stable 37 output to close either switch 35 or 36, the closed switch being associated with the primary radar being utilized when U sym b is produced. Voltages X roll and Y roll defining the marker position are corrected in units 25, 26 for offset of the primary radar sites and compared with the polar PPI deflection voltages (Fig. 4, not shown). When these are equal the secondary radar information from the selected target is passed through the closed switch 35 or 36 to the appropriate decoder which provides a read out of target interrogation, height, target codes &c.