Optically Significant Cirrus Clouds may be Rendered "Invisible" to Space-borne Simple Lidar Systems

Recently, there has been much discussion among lidar researchers concerning the infinite solution set of extinction profiles which can be produced from a given simple-lidar backscatter profile1. This ambiguity is caused by the measured backscatter signal dependence on both the backscatter cross section and on the profile of extinction. Simple lidar systems produce only one measurement from which to deduce these two range-dependent parameters. Thus, simple lidar measurements must be augmented by additional measurements or knowledge of the physical relationship between backscatter and extinction before meaningful profiles of extinction can be produced. One simple lidar retrieval method assumes independent knowledge of extinction at at least one range and an assumed relationship between the backscatter cross section and extinction2. A second method seeks a common solution to several simple lidar profiles produced by observations at different viewing angles3,4,6.