| 摘要 |
1,211,160. Pulse radar. DECCA Ltd. 18 July, 1969 [12 Aug., 1968], No. 38387/68. Heading H4D. A marker is placed accurately on a rangebearing radar display 12 by producing in unit 22 a count of digitized azimuth, producing a pulse in circuit 24 when the required marker bearing set in digital store 25 is reached by the count, setting bi-stable 28 with the produced pulse, forming a range gate in generator 30 of a duration equal to maximum required marker range when the bi-stable is reset by the radar trigger which succeeds the setting of the bistable, sending pulses from oscillator 31 during that range gate to counter 32 the count in which is compared with required marker range set in digital store 35, and on coincidence generating an intensity-modulation pulse for display 12. The range and bearing stores may comprise manually operable keys. The marker pulse may be applied simultaneously to a number of displays, some of which are P.P.I. and some type B; and any display be an offset type showing only part of the radar coverage. To display several markers in different positions the range and bearing stores store all the necessary data and generator 30 is also arranged by connection 37 to afford a " step-on " signal to those stores such that range and bearing information for the next required marker is supplied to coincidence circuits 34, 24. |
