LASER RADAR DEVICE

摘要

A laser radar is provided that comprises a laser beam source arranged to generate a laser beam, means for changing an elevation angle of a beam axis of the beam, means for controllably adjusting anisotropy of a cross- section of the beam and a controller configured to control adjustment of a degree of anisotropy of the beam in correspondence with changes of the elevation angle. The laser radar may be used for example with the beam directed downward at grazing angles to a surface, the controller being configured to increase the degree of anisotropy with increasing angle to a direction of the surface. In this case, elevation angle corresponds to distance to the target. By adjusting anisotropy with distance, higher sensitivity can be realized at long distance and less scans are required to cover shorter distances. A beam with a diverging profile may be used, which diverges anisotropically, with selectable divergence in the elevation direction and constant divergence perpendicularly to the elevation direction. This may be realized using movable or rotatable cylindrical lenses, reflectors or refracting optical elements.