The system and method relate to detection of objects that are submerged,
or partially submerged (e.g. floating), relative to a water surface. One
aspect of the invention emits LIDAR fan-beam pulses and analyzes
return-pulse portions to determine water-surface orientations and derive
submerged-object images corrected for refractive distortion. Another
defines simulated images of submerged objects as seen through waves in a
water surface, prepares an algorithm for applying a three-dimensional
image of the water surface in refractive correction of LIDAR imaging
through waves--and also models application of the algorithm to the
images, and finally specifies the LIDAR-system optics. Yet another emits
nearly horizontal pulses to illuminate small exposed objects at tens of
kilometers, detects reflected portions and images successive such
portions with a streak-tube subsystem. Still others make special
provisions for airborne objects.