The basic parameters (range, signal-to-noise ratio, and sensitivity) of a lidar using NH3 and CO2 lasers are calculated. The principle of lidar operation is based on the differential absorption recording. Absorption spectra of all known Freons are considered in the spectral range 9-13.5 mu m and optimal wavelengths suitable for sensing them are determined. It is shown that the NH3-CO2 lidar can sense Freons at distances up to 10 km at a signal-to-noise ratio exceeding 10. Sensitivities of the lidar for sensing Freon-11 using various lines of the ammonia laser are calculated. It is shown that remote sensing of Freon-11 at concentrations of the order of 5 x 10(-6) % is possible at distances up to 8.5 km.
- NH3-CO2 lidar
- differential absorption
- DIFFERENTIAL-ABSORPTION LIDAR
- REMOTE MEASUREMENT
- 2-FREQUENCY LIDAR