Frequency-modulated multifunction lidar for anemometry, range finding, and velocimetry-2. Experimental results

Frequency-modulated continuous-wave lidar is evaluated for range finding, velocimetry, and laser anemometry. An original signal processing and waveform calibration for range finding leads to a reduction of computational effort while preserving capability for long-range measurement. Multiple target distance measurement is also demonstrated. For laser anemometry, the aim is to avoid parasitic echoes in the vicinity of a helicopter and to measure the air speed at the shortest distance farther than the rotor-induced turbulent volume around the helicopter. Flight tests of this functionality and vortex ring state warning are demonstrated.