Patent ID: 7260507

Claim:
A method for improving the calculation of a concentration path length (CPL) of a DIAL beam in a differential absorption LIDAR (DIAL) system by increasing signal to noise ratios of measured pulse energies of the DIAL system, the method comprising the steps of: a) scanning the DIAL beam such that the DIAL beam is transmitted through a plurality of measurement points, the DIAL beam including an online laser beam and an offline laser beam transmitted collinearly; b) measuring a plurality of transmitted pulse energies of the online laser beam and a plurality of transmitted pulse energies of the offline laser beam corresponding to the plurality of measurement points; c) measuring a plurality of received pulse energies of the online laser beam and a plurality of received pulse energies of the offline laser beam corresponding to the plurality of measurement points; d) selecting one measurement point; e) selecting a region of interest (ROI) subset of measurement points within a ROI around the one selected measurement point; f) calculating, for the one selected measurement point: an average transmitted online pulse energy from the transmitted pulse energies of the online laser beam of the selected ROI subset of the measurement points; an average transmitted offline pulse energy from the transmitted pulse energies of the offline laser beam of the selected ROI subset of the measurement points; an average received online pulse energy from the received pulse energies of the online laser beam of the selected ROI subset of the measurement points; and an average received offline pulse energy from the received pulse energies of the offline laser beam of the selected ROI subset of the measurement points; and g) calculating the CPL of the DIAL beam for the one selected measurement point using the average transmitted online pulse energy, the average transmitted offline pulse energy, the average received online pulse energy, and the average received offline pulse energy; and providing the calculated CPL to a user.