Development of a two frequency downward looking airborne LIDAR system

Extensive testing and operational experience gained with two existing airborne LIDAR systems have demonstrated the utility of such devices for monitoring the height of elevated inversion layers representing mixing depths over large geographical areas in relatively short periods of time. During several field testing missions using a prototype system, both point source and urban plume measurements were obtained suggesting even greater utility to this type of device. The two-wavelength downward looking LIDAR responds to the following specific monitoring problems: 1) The determination of mixing layer height over relatively large geographical areas in short time periods. This type of information is particularly useful in determining the behavior of the mixing layer height during morning and evening transition periods. 2) The determination of point source plume dimensions referenced to a ground coordinate data base. The information can be used not only to characterize the plume behavior but also the position sampling aircraft using in-situ techniques. Obtaining dimensions and point source components of urban or other multi-source plumes. The data are of principal interest to modelers but in some cases can also be of interest in pinpointing emissions violations. Although the three monitoring problems all utilize downward looking airborne LIDAR systems, the monitoringmore » requirements are substantially different for each.« less