GB1377032A - Circuit arrangements for range measurement in a radar unit - Google Patents

Abstract

1377032 Pulse radar SIEMENS-ALBIS AG 27 Dec 1972 [21 Jan 1972] 59665/72 Heading H4D In a radar unit a first, fast response, range measuring device initially tracks a target while a high inertia, but accurate range measuring device catcher up with the target, tracking eventually being transferred to the second device, the system including means to enable the first device to be set to a second target while the second device is tracking the first target so that tracking of the second target can be started when desired i.e. when tracking of the first target can be terminated. It is stated that the system can operate with smaller range gate widths than prior out systems. A range gate 1 is initially connected to a fast response range measuring device 2, the echo pulse being applied at Z. Switches 9a, 9b, 9c are then in the position shown. Devices 1, 2 form a tracking system for the target. A second range measuring device 3 is connected by a mechanical shaft 11 to a computer 5. Both devices 2, 3 give pulses indicating the range value being tracked and these pulses are fed to a device 4. The output U4 of this device corresponds to the difference in the range values in devices 3, 2. Output U4 is fed via switch 9a to device 3 so that the range value stored in this device'is shifted towards that in device 2. Eventually the range values in devices 2, 3 are nearly equal and, when they are closer than a threshold, switch 8 causes switches 9a, 9b, 9c to change over so that device 1 is now connected to range measuring device 3 which proceeds to take over the target tracking. As switch 9a has changed over the output of device 4 is connected to device 2 which is thus slaved to the range value in device 3. If another target is to be tracked, switch 12 is operated to connect a second output of device 3 via a delay 6. The delay is adjusted to cause the range stored in device 2 to be that corresponding to the expected locality of the second target. A display 10 gives light markers corresponding to the pulse from devices 2, 3 at their respective time positions, delay 6 being adjusted until the light marker from device 2 is at the position corresponding to the new target. By placing switches 9a, 9b, 9c back into their initial positions devices 1, 2 again form a tracking system which now tracks the new target. As before, device 3 eventually takes over the tracking.