Rangefinder for imaging system eliminating effect of rotor rotation
AssigneeThe Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorAlan H. Lettington
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Abstract
An optical imaging system is provided with a pulsed laser rangefinder comprising a transmitter 10 aligned with the boresight of the imaging system, the return pulse being focussed by the telescope 6 of the imaging system upon its multi-mirror, two-rotor arrangement 2, 3 and reflected then to a detector 12 and display 13. To eliminate the effect of rotor rotation during the time-of-travel of the pulse, the latter is first reflected from the rotors to a beam reverser 14 including a 90 degree roof-reflector 18 (FIG. 2), which reflects the pulse back to the rotor mirrors in the same vertical plane and then to detector 12 along a path having a fixed spatial relationship to the path to the imaging-system detector 8.
Claims9
An optical imaging system comprising a rotatable scanner, said scanner comprising a plurality of mirrors extending round a rotor, and an optical system for directing light-radiation from a scene being scanned on to said rotor mirrors and thence to a detecting means, wherein there is further provided rangefinder means including:
- a light transmitter having its boresight aligned with that of said optical directing system whereby the transmitted light returned from the scene by reflecting thereat is received by said optical directing system and likewise directed on to said rotor mirrors;
- and light-beam reversing means arranged to receive said returned light after reflection from said rotor mirrors and to reflect said returned light back to said rotor mirrors along a path having a fixed angular relationship, in a plane parallel to the axis of rotation of the scanner, to its path on initially leaving said rotor mirrors whereby said returned light is then reflected from said rotor mirrors to a detecting means along a path having a fixed angular relationship, in a plane parallel to the axis of rotation of the scanner, to that of the light-radiation from the scene to the first-mentioned detecting means.
Dependencies are inferred from the claim text.