Abstract

A multiple-field-of-view lidar has been developed, which makes simultaneous measurements of the direct backscattered lidar signal and multiscattered signals. The source is a Q-switched Nd:glass laser operating at 1.054 μm. The pulse energy is 1 J, the pulse duration is 25 ns, the pulse repetition rate is 0.1 Hz, and the divergence is 3 mrad. The novel feature of the instrument is the multielement detector, which consists of four concentric silicon photodiode detectors with active area diameters of 1.5,5,10, and 15 mm. Placed at the focus of a 150 mm f/1.33 lens assembly, the detector defines half-angle fields of view of 3.75,12.5, 25, and 37.5 mrad. The central field of view receives the direct backscattered power from the outgoing laser pulse, and the outer fields of view receive multiscattered contributions. The signal from the central detector constitutes a conventional lidar signal.

© 1990 Optical Society of America