Patent ID: 7739823

Claim:
A fire control system comprising: a LIDAR (laser identification, detecting and ranging) unit comprising a laser adapted to transmit a beam to a target, a collecting lens for receiving a beam returning from the target, and receiver optics comprising a multi-element detector array at a focal plane of the collecting lens, wherein for each element of the multi-element detector array there is a specific optical path in the atmosphere leading from the laser to the target and back from the target to the element; and processor apparatus operative to measure signal fluctuations of an element of the multi-element detector array, and compute therefrom crosswind velocity of wind in the atmosphere, wherein said processor apparatus is operative to calculate turbulence strength changes and wind fluctuations insensitivity for optical paths longer than 500 m by: choosing fluctuations that act as refractive lenses with focal lengths on the order of hundreds of meters or more, wherein the fluctuations comprise eddy cells with a spatial scale of l w ˜ρ 0 for weak fluctuations range, and l s ˜L/kρ 0 for strong fluctuations range (L—path range, k—wave number, ρ 0 =(1.46 C n 2 k 2 L) −3/5 —coherence radius for plane wave), wherein corresponding spatial frequencies are k w ˜1/ρ 0 for weak turbulence and k s ˜kρ 0 /L for strong turbulence.