Remote particle counter for remote measurement of the number and size distribution of suspended fine particles in the atmosphere

A remote particle counter in a radar apparatus for remote measurement of a number and size distribution of suspended fine particles in the atmosphere comprising a control/analysis system that performs not only overall control of the system but also data measurement and analysis, a pulsed laser generator, laser beam emitting optics for transmitting a spread beam of laser light toward the atmosphere, scattered light collecting optics by which backward scattered light that occurred from fine particles upon illumination with laser light is collected on a detector, and a high-sensitivity two-dimensional photo detector having a fast gating capability,

• wherein a target area in which a population of fine particles suspended over a certain area of the atmosphere at a certain altitude is illuminated with pulsed laser light of a wide beam spread which has been emitted from the laser generator controlled by the control/analysis system and which has passed through the laser beam emitting optics, and backward scattered light from the distributed atmosphere fine particles is collected by the scattered light collecting optics to be picked up by the high-sensitivity two-dimensional photo detector, which is controlled by the control/analysis system to measure the number and size distribution of the fine particles;
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• wherein by controlling the direction of laser emission and the delay time from laser emission of the fast gating of the high-sensitivity two-dimensional photo detector, the number and size distribution of fine particles suspended in a cylindrical space of the atmosphere which is away from the position of laser emission is obtained.