A laser telemeter having separate transmitting and receiving optical systems, and at least monocular target observation, in which a telescope optical system (5, 6) which is inserted before the transmitting optical system (2) and reduces the divergence of the transmitted beam, a telescope optical system (7, 8) which is inserted before the receiving optical system (3) and has an aperture angle adapted to the divergence of the transmitted beam and a common support frame (9) for the telescope optical systems (5, 6; 7, 8) which can be coupled at the front with the housing (10) of the laser telemeter (1) are provided.

Measuring method and device providing a traveling path of light beam. The traveling path includes a front portion between a target and a prism unit, a refraction portion entering the prism unit and extending inside the prism unit and a first and a second rear portions positioned outside the prism unit and corresponding to the front portion. A visible light beam and an invisible light beam at the same time travel along the front portion. The visible light beam comes from the surface of the target while the invisible light beam is a laser beam coming from a laser transmitter. The laser beam travels along the same path as the visible light beam to reach the surface of the target. Therefore, very long parts of the traveling paths of the visible light beam and the invisible light beam coincide with each other and are commonly directed to a specific portion of the target. Accordingly, a better measurement precision can be achieved and the volume of the device can be reduced

A countermeasure-detecting circuit, and associated method, for a laser speed detector. Countermeasures taken at a moving target, such as a vehicle, to interfere with operation of the laser speed detector are detected. When countermeasures taken at the moving target are detected, the sensitivity of the laser speed detector is altered to overcome the effects of the countermeasures.

A traffic LIDAR device is presented with an increased laser power output in compliance with the IEC 825 standard for class one-type laser systems. Increased laser emitter power output is accomplished by reshaping the emitter source output using an optical fiber which has an inside diameter greater than the minimum dimension of the emitter source. The resulting increased cross-section of the output pulse overcomes the power output limitation that would otherwise be dictated by the emitter minimum dimension.

In an environment monitoring system using an optical flow, an optical-flow detecting device detects the optical flow in the steps of reverse-projection converting the early image of two early and later images picked up by an image picked up, on the basis of a predetermined optical arrangement of the image pick-up means onto an x-z plane in parallel to a road surface in a real space to acquire a road surface image; computing a moving distance of one's own vehicle in two timings on the basis of a time interval between two timings and speed information of one's own vehicle; parallel-shifting the road surface image by the moving distance thus computed; projection-converting the road surface image after parallel-shifted to acquire an estimated image of the later image in timing; acquiring a differential image between the later image and its estimated image to extract a feature point; and searching a corresponding point of the feature point extracted. In this configuration, it is possible to prevent an object such as a paint which should not be detected on a road surface from being erroneously detected as another surrounding vehicle.