3-D tomographic imaging of ocean mines from real and simulated lidar returns

Airborne lidar provides an effective method for detection and localization of underwater objects, where the transmitted laser beam can penetrate the air-water interface and illuminate the scatterers within the water column, and the optical field generated by this scattering can be collected and processed. Here, we consider the use of lidar data collected from different observation angles of a particular water volume to image objects of interest. Interpreting the lidar returns as tomographic projections of a 3-D reflectivity field, we formulate the problem as a 3-D tomographic image reconstruction problem. We show tomographic reconstructions from both real and synthetic data sets. The real data was collected by a Lockheed-Sanders lidar system in a U.S. Navy field test. The synthetic data is produced by using an accurate statistical model that incorporates multiple scattering.