A differential imaging system is particularly efficacious for detecting
objects in high dispersion or light-scattering mediums, such as seawater.
Such a device especially useful in mine detection. A single burst of
illumination is used as the light sensitive portion of the system is
gated so as to collect at least two images of reflected light from the
same burst of illumination. The first image is modified and subtracted
from the second image to remove the common noise, and to further enhance
the image of the object to be detected.