Abstract: The angle of divergence of a laser beam (29) is controlled without significant variation of beam power by using a movable corner cube (18) to vary the length of the optical path of a noncollimated beam (12) so as to present a beam of varying diameter to a telescope lens (26). In a second aspect of the invention, the beam is made insensitive to vibration of the corner cube (18) by covering a portion of its beam-receiving face with a second reflector (32) which causes the beam to make a second pass through the corner cube (18) in a parallel but opposite direction therey cancelling any beam displacement caused by the vibration of the corner cube (18).

Abstract: A beam projector which is controlled to alternately transmit rectangular cross-sectional beams substantially parallel to a projection axis, wherein the beams are respectively pulse modulated over a correspondingly distinct pulse rate frequency range to supply yaw and pitch information and are respectively scanned in a direction correspondingly orthogonal to the cross-sectional length of each beam. The size format of the beam cross-sections and the angles of scan are controlled according to a predetermined time variable function. In a first time period, the largest cross-sectional beams are alternately transmitted and the scan angle is decreased as a function of time, so that a fixed area of detectable information is available for detection with respect to an imaginary orthogonal reference plane moving along the projection axis at a rate corresponding to the predetermined time variable function.

Abstract: A beam projector which is controlled to alternately transmit rectangular cross-sectional beams substantially parallel to a projection axis, wherein the beams are respectively pulse modulated over a correspondingly distinct pulse rate frequency range to supply yaw and pitch information and are respectively scanned in a direction correspondingly orthogonal to its cross-sectional length. The size format of the beam cross-sections and the angle of the scan are controlled according to a predetermined time variable function. In a first time period, the largest cross-sectional beams are alternately transmitted and the scan angle is decreased as a function of time, so that a fixed area of detectable information is available for detection with respect to an imaginary orthogonal reference plane moving along the projection axis at a rate corresponding to the predetermined time variable function.