Differential absorption lidar device

摘要

PPROBLEM TO BE SOLVED: To provide a differential absorption lidar device capable of detecting received light even when a Doppler frequency shift is generated by measurement while moving. PSOLUTION: The device includes: optical signal generation means 1-3 generating first and second CW transmission optical signals and a CW local optical signal; frequency shift means 4a, 4b and 5a providing a first frequency shift to the second CW transmission optical signal, and a second frequency shift to the first CW transmission optical signal; radiation means 6-9 radiating a two-wavelength optical signal into the space; light reception means 9 and 10 receiving scattering light from a target as reception light; a beam irradiation spot tracer 11 sequentially controlling the light reception means to enter an irradiation spot of a transmission beam on the target in a reception visual field; and concentration detection means 5b, 5c, 12 and 13 subjecting the first and second CW local optical signals and the reception light to heterodyne detection to be converted to electric signals, and extracting second and first frequency shift components to detect concentration of the target from the difference between intensities thereof. PCOPYRIGHT: (C)2008,JPO&INPIT