Abstract
The angular and temporal distributions of energy in the reflection of a pulsed laser beam from a sea surface depend on the diameter of the beam and on the wavenumber spectrum of the water surface. Theoretical expressions are derived for the influence on the reflection of the mean height and slope of waves in the illuminated area as well as the variation of the height and slope within this area. The results are applied to airborne lasers for wave height profiling, altimetry and water depth sounding. The optimum beam diameter depends on both the application and the wavenumber pectrum of the water surface.