Abstract: Red-Green-Blue color-coding of overlaid registered stereo pair imagery from different spectral regions (for example, near-, mid-, and far-infrared) can be used to derive depth perception information. The human preattentive vision process uses coarse spatial structure in the scene to fuse the images for the detection of depth and motion cues. Optimization is accomplished by assigning green to the lowest spatial frequency content image, then red to the next lowest, and finally blue. If the fusion of one of the colored imagery layers produces depth perception information in one portion of the scene whereas the other two colored layers do not, the human mind can retain the information from this color and discard the inputs from the other two colors as noise. The same is true for the other two colors. Human color discrimination and depth perception are combined to greatly enhance preattentive object recognition in the fused stereo pair imagery.

Abstract: A system for enhancing underwater visibility is described that uses left and right alternately chopped laser illumination, filtered wide baseline stereo imaging and specular reflectors for deblurring the images. Two stereo images are compared to determine the pattern of backscattered light and the resultant backscatter pattern is subtracted from the images. Inverse point spread filtering based on the fusion of the specular reflector pattern is next performed to further improve the images, and stereoscopic is display for enhanced visibility in turbid and murky mediums. The invention has broad application for underwater exploration and search and recovery operations, and is especially useful for detection and removal of underwater mine hazards.

Abstract: A method for approximating dynamic effects of atmospheric turbulence on infrared digital imagery utilizing the application of at least one spatially varying system to an object intensity distribution to obtain at least one image intensity distribution. The spatially varying system represents atmospheric turbulence which varies phase and/or amplitude as a function of a spatial index. The object intensity distribution and the image intensity distribution are related by an image warping transformation. Two configurations for experimental verification of the utility of a turbulence simulation technique are also disclosed.

Abstract: A thermal test target with a uniform surface temperature which can be used to characterize and measure thermal image degradation due to atmospheric propagation of the image radiation field. This thermal test target board produces very uniform spatial frequency patterns with near perfect transitions between hot and cold portions which do not change during the diurnal cycle and which are not impacted by environmental changes.

Abstract: Near real time remote sensing of atmospheric gases is performed using differential absorption lidar or transmission techniques. The wedge absorption remote sensor (WARS) utilizes an emission spike train of short time duration as is found in the long pulse output mode of a solid-state laser to define the on and off line absorption of an atmospheric gas and hence its concentration. The laser beam is split into a reference beam and a transmission beam which passes through the atmosphere being tested. The two beams are detected and amplified, and them digitized. Comparing the ratio of the digitized reference signal to transmitted signal for each spike in the spike train yields a set of transmittance values as a function of wavelength. When the digitized reference and transmitted signals are plotted, a wedge of data points results. The ratio of the upper and lower slopes of the wedge yields the absorption coefficient and concentration of the absorbing gas.

Abstract: Nearly time independent measurements of low-absorption coefficients of atmospheric constituents can be made with long-path absorption cells by obtaining short-term averages of transmittance values related to cell mirror reflectivity through rapid changes in the cell pathlength between short and long multipaths.