Depth sounding lidar model with multipixel receiver

In this report we present a theoretical model for depth sounding lidar (light detection and ranging) with the ability to simulate modern multipixel lidar receivers with several detectors. The model is valuable for target signature studies, performance estimation of target detection, estimation of surface wave signals and development of signal processing for water volume turbidity estimation or sea bottom classification. The modeling results are exemplified with two simple configurations of a four-pixel lidar receiver. The theoretical results show that signals from a multipixel system can be used to estimate the local sea surface slope angle within one laser shot. The results also show that a sea surface correction factor could be applied to improve the estimation of the sea bottom properties from the bottom echo and that the use of specific pixel information for certain pixel geometries can improve the performance for target detection when the detection is limited by the volume backscatter signal. The multipixel lidar model uses a ray-tracing method that accounts for transmission through a sea surface with both large and small scale waves (ripples) as well as multiple scattering of the laser pulse within the water volume.