Lidar inversion algorithms for terrestrial and Martian atmospheres

The performance of traditional lidar inversion algorithms for the extraction of aerosol and cloud optical properties, and their applicability to the Dalhousie Raman Lidar and Phoenix Mars Lidar is assessed. Modifications are proposed to overcome limitations of the algorithms. The traditional Klett solution is shown to work well for the inversion of lidar signals from cirrus clouds, and a method of determining the uncertainty in the lidar ratio due to random noise is demonstrated. An algorithm for calculating aerosol optical properties in the incomplete overlap region of lidar systems is derived and tested. The overlap independent backscatter ratio equation is solved using a Bernoulli solution to produce an equation for the aerosol extinction coefficient and lidar ratio. When applied to modeled lidar signals the new algorithm correctly produces optical properties in the incomplete overlap region. Noise affects the ability of the algorithm to produce accurate results for measured data. In these cases, ancillary data is used to constrain the algorithm. A single-component atmosphere solution, constrained by an optical depth measurement, is tested for the inversion of Martian lidar signals. Application of the solution to modeled lidar signals produces accurate extinction coefficient profiles.