Lidar Observation of Cloud

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Science  27 Aug 1965:
Vol. 149, Issue 3687, pp. 978-981
DOI: 10.1126/science.149.3687.978


Lidar (from "light detection and ranging") is the optical counterpart of meteorological radar. At optical wavelengths, very much smaller atmospheric particles can be detected than at microwave wavelengths. With a laser power source, a transmitter uses a lens system to beam very intense pulses of monochromatic light of extremely short duration. Light backscattered by the atmosphere is collected in a receiver system that is essentially a telescope coaligned with the transmitter, and a narrow-pass filter allows only light of the transmitted frequency to be detected by a photomultiplier. Data are presented on an oscilloscope as a trace of signal intensity versus range (the A-scope of radar practice) and photographed.