GB818494A - - Google Patents

Abstract

818,494. Radar. ALBISWERK ZURICH A.G. Sept. 3,1956 [Sept. 2, 1955], No. 26909/56. Class 40 (7). Relates to a ship-borne radar system for directing anti-aircraft guns comprising an unstabilized search radar 1 which determines the azimuth α<SP>1</SP>z of a target relative to the unstable deck plane and a fire-directing radar 3 stabilized against roll # and pitch y, the azimuth αz of the target in the stabilized co-ordinates being given by where t is the target elevation. In a first embodiment the aerial 2 of the search radar 1 rotates continuously about an axis normal to the deck plane and the instantaneous azimuthal position α<SP>1</SP> of the aerial 2 in said plane is applied together with the roll and pitch angles # and y and the mean angle of elevation # of the aerial 4 of the stabilized radar 3 to a computer 5 which computes in accordance with the above equation the corresponding azimuth angle α in the stabilized co-ordinates. The output α from the computer 5 is applied to control the angular co-ordinate of a search P.P.I. 6 and a rotatable cursor is continuously aligned with the target response to produce an electrical signal representing the stabilized target azimuth αz which is applied to control the azimuth position of the aerial 4 of the stabilized radar 3. The aerial 4 scans in elevation about the mean angle # until the target is detected. In a modification, Fig. 2 (not shown), the angular co-ordinate of the P.P.I 6 is controlled directly by the unstabilized azimuth angle α<SP>1</SP> and corresponding values of α<SP>1</SP>, # and y are continuously stored during each rotation of the aerial 2. The cursor on the P.P.I. 6 now produces an unstabilized target azimuth signal αz<SP>1</SP> which is applied to the storage device to produce corresponding values of # and y which are applied together with α<SP>1</SP>z and the instantaneous elevation t of the aerial 4 to the computer 5 to produce the required signal αz.