A wind tunnel study was performed to determine the size spectra produced by spray atomization systems currently in use by the U.S. Forest Service. The atomization systems were assessed dynamically using a remote sensing laser particle spectral analyzer (LPSA) developed by Aerosol Science Laboratory personnel at the Colorado State University. The LPSA system, which is mounted on a traverse having three degrees of freedom, is capable of in-situ remote measurement of the size distribution of particles from 1 to 200 micrometers traveling inside a wind tunnel. Performance of the LPSA system was analyzed, and an absolute calibration method was developed. Two types of spray nozzles were placed in a high speed wind tunnel in an effort to establish droplet spectra under actual aircraft flight conditions. Size distributions of droplets produced by the two nozzles were characterized at two different wind speeds using the LPSA system.