Shallow Angle Wave Profiling LIDAR

A LIDAR scanning system is described which is primarily designed to measure sea wave shape. The device is capable of measuring real-time spatial profiles over distances of hundreds of metres and as the LIDAR must inevitably operate from modest elevations, eg., from a vessels mast head it is inherently a very shallow angle metrology device. This results in a highly nonuniform distribution of the wave elevation values. The vertical and horizontal resolution is primarily set by the characteristics of the optical system employed and range/data capacity is set by signal to noise ratio considerations. Illustrative data is presented as consecutive profiles taken 0.2 sec apart for highly trochoidal wave under conditions where the height was recorded to +_ 0.03 m and horizontal sample separation to +_0.025 m. A comparison is presented with traditional wave staff measurements.