GB990367A - Improvements in or relating to semi-automatic radar tracking devices - Google Patents

Abstract

990,367. Radar. SOC. NORVELLE D'ELECTRONIQUE ET DE LA RADIO INDUSTRIE. July 6, 1961 [July 27, 1960], No. 24520/61. Heading H4D. Relates to a rate-aided manual tracking system for an azimuth scanning pulse radar in which echoes from a target within an adjustable two-dimensional window area are selected by a corresponding window gate, the window area being indicated on a P.P.I. display by a corresponding adjustable window marker. According to the present invention the position and rate of displacement of the window marker are controlled to maintain the target echo in the centre of the window marker by means of a control panel 1 of the same shape as the window marker, the control panel being subdivided into a plurality of segments each containing a pushbutton. In operation, if the target echo moves from the centre of the window marker the operator actuates the push-button corresponding to the new (displaced) position of the echo to generate the required marker control signals. As described, radial and angular components (polar co-ordinates d, #) of the control signals are generated but it is stated that orthogonal (cartesian) components may be used. As shown, when a push-button, e.g. 3, is depressed it triggers on a pulse generator 9 and sets up in a corresponding one, 140, of a plurality of digital registers 14 a number n proportional to the radial displacement of the push-button 3 from the centre of the control panel. When the number of output pulses from the pulse generator 9 as determined by a counter 11 is equal to the number n set in the register 140, the register produces an output which is applied through an OR gate 15 to stop the pulse generator 9 and counter 11. The output from the pulse generator 9 is also applied (1) through the counter 11 and a selector switch 16 to a distance error counter 6 to give a radial position error signal ep the sign of which is controlled by the push-button 3 via a connection 7 and the scale of the signal ep being determined by the setting of the switch 16, and (2) to a divider 12 where the pulse train is divided by the time interval # that has elapsed since any previous corrective action to give a radial velocity error signal ev = #p/#, the value of # being determined by a timing circuit 17 controlled by the push-button. The outputs ev and ep from the divider 12 and counter 6 are then combined in an integrator 13b to give the signal which controls the radial position of the window marker; as shown the output ev from the divider 12 is applied to the integrator 13b via a velocity storage counter 13 and an AND gate 13a coupled to the timing circuit 17. The angular position control signal is generated in a similar manner by the corresponding units 61, 91, 111, 144<SP>1</SP>, 20, 21a and 21b. Specification 947,378 is referred to.