Long range laser ranging device

Abstract

A high speed laser ranging device composed of a transmitter/receiver unit and a target including a retroreflector adapted to receive a laser pulse (Ii) transmitted by the unit and to return it parallel to itself. This transmitter/receiver unit travels, with respect to the target, along a relative path with an overall relative velocity V, and normal to an instantaneous line joining it to the target, with a transverse relative velocity v.sub.t which, on average, is of the order of at least 1 km/sec. The retroreflector has a cube corner shape with three reflecting plane faces, two of which are normal to the third one, and forming between each other a dihedral angle (7.sub.1) referred to as the 'corrected dihedral angle', differing from 90.degree. by a deviation value .epsilon. at least equal to one arcsecond. The 'corrected dihedral angle' is contained within a plane (P) passing through the axis (n) of the cube corner and is at least approximately normal to the average orientation of the transverse relative velocity V within the field of view (C) of the cube corner and the deviation .epsilon. ranges between the minimum and maximum values of v.sub.t /(c. sin .THETA.), in radians, within this field of view, where .THETA. is the angle between the instantaneous line and the corrected dihedral angle, and where C is the speed of light.