Date: 04/24/09

Speaker: X. Zao

Title: 
Radiometric underwater imaging under dynamic ocean surface waves

Abstract:
Many studies have been taken on imaging the underwater objects from
airborne cameras. Most imaging system acquires the exact image of the
object on the CCD plane. In our radiometric underwater imaging system,
the object is placed above water surface and its image is projected to a
spherical detector in the water. In both cases, the dynamic ocean
surface waves play an important role on the image qualities. However,
due to the difference on imaging mechanism of this two image system, the
effects of surfaces waves are also different.

Our numerical study about the effect of dynamic ocean surface waves on
radiometric underwater imaging is based on the 3D Monte Carlo
atmosphere-ocean-system radiative transfer model. The point spread
function (PSF) is investigated under different dynamic ocean surface
waves and different water optical properties. The simulation results
show PSF is influenced by several factors: wave steepness, wave length,
single scattering albedo, detector location. To demonstrate this effect
on imaging quality under different surface waves, we investigate the
image contrast of a black-white stripe source. It shows the image
contrast is decreased or image gets blurrier under larger steepness
waves, larger single scattering albedo and deeper detector location.