Qinetiq Limited

Martin Johnson

Robin Jones

Adrian Sean Coffey

Michael Harris

Richard Paul Scullion

Selina A Ballantyne

A measurement device, such as a laser radar, is described that comprises a transmitter portion for transmitting radiation to a remote probe volume, a receiver portion for detecting radiation returned from the remote probe volume and a processor for analysing the detected return radiation. The device is suitable for transmitting and receiving radiation through a window portion having associated window cleaning apparatus (e.g. wiper) for cleaning said window portion in response to a cleaning activation signal. The processor is arranged to generate a cleaning activation signal for activating window cleaning apparatus when the properties of said detected return radiation are indicative of a reduction in transmission through at least part of said window portion. In one embodiment, a conically scanned lidar is described that generates a cleaning activation signal when the power of detected return radiation varies as a function of the angle of transmission of radiation from the device.

Laser measurement device and method

An apparatus for producing a digital depiction of a signal ( ) which is adaptive to the signal itself. A constant rate sampling means, such as an analogue to digital converter ( ), samples the signal ( ) at a constant rate and produces a first digital depiction ( ) of a signal. A transformation means ( ) is responsive to the first digital depiction ( ) and produces a second digital depiction based on the evolution of the signal. The transformation means may be capable of determining when a predetermined threshold level has been crossed and measuring the time interval between predetermined threshold level crossings. The transformation means ( ) may include a logic arrangement and a timer counter and is run from a clock signal ( ) from the same clock ( ) as drives the sampling means. A method of adapting a conventional ADC ( ) to adaptively sample the signal ( ) by adding a transformation means ( ) run off the same clock ( ) as the ADC ( ) is also provided.

Method and apparatus of producing a digital depiction of a signal

An analogue to digital converter generating at least two threshold levels and a comparator for comparing each of the levels with the input signal and generating a primary digital output signal to provide an indication that the input signal has crossed one of the threshold levels. The converter comprises a timer for determining the elapsed period of time between the input signal crossing a first level and the input signal crossing a second level and for generating a secondary output signal representing the elapsed time, whereby the secondary digital output signal and the corresponding primary output signal are used to provide a digital representation of the analogue input signal. The converter may also comprise a receiver of the primary digital output signal from the comparator and for providing an UP/DOWN digital output signal to indicate in which direction the input signal crossed the threshold level.

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Malvern, United Kingdom

Martin Johnson