Compact dual wavelength 3.30 to 3.47-μm DIAL lidar

A compact (2'6' X 2'5' X 1'1') 3.30 - 3.47-micrometers DIAL lidar has been constructed for base remediation and chemical monitoring. The lidar system is designed for short range (0.5 km maximum) aerosol backscatter detection of light hydrocarbons with sensitivities at parts-per-million level in a 30-m ranging bin. The system can also operate in the topographic mode. The on-line and off-line wavelengths are produced sequentially using a dual crystal intra-cavity KTA OPO. Detection is by means of an 8-in Newtonian telescope coupled to a Stirling cycle cooled InSb detector. The system incorporates an onboard digital signal processor and controller, operator's interface is furnished by a laptop PC. Results of initial tests using diesel fuel and a solvent are presented.