Abstract
Atmospheric minor constituents related to earth warming have many absorption lines in the IR region. Recent progress in high power IR tunable lasers makes the detection of these species possible by the differential absorption lidar (DIAL). This paper describes the theoretical analysis of the detection range of the IR range-resolved DIALs. At first, the detection ranges are generally calculated over a wavelength range from 200 nm to 16μm. For the ideal absorption line strength, the typical detection range in IR is 3-4 km in the vertical distribution measurement, but it increases to 10 km in the horizontal distribution measurement. Based on the HITRAN database, we surveyed useful absorption lines for DIAL measurement in the 1-5μm range, and found that CO2, CH4, N2O and CO were detectable besides H2O. Detailed simulation of the DIAL measurement was made for each of the absorption lines of these molecules, and it was shown that the range-resolved DIAL method was useful for the detection of these four species.
