Three dimensional moire pattern alignment

An apparatus is disclosed for determining three dimensional positioning relative to a predetermined point utilizing moire interference patterns such that the patterns are complementary when viewed on axis from the predetermined distance. Further, the invention includes means for determining rotational positioning in addition to three dimensional translational positioning

Optical correlators for automated rendezvous and capture

Two dimensional image correlation is a robust technique for recognizing known objects and determining their position with respect to the sensing platform. This capability is of paramount importance to vehicles which must rendezvous and capture using only on-board sensors and processors. Standard digital processors can provide the necessary correlations, but their speed, weight, size and power consumption make them undesirable components of an on-board tracking system. Optical correlators provide correlation results comparable to digital systems, but with a fraction of the size, weight and power and often many times faster. This presentation discusses the application of optical correlators to Automated Rendezvous & Capture (AR&C), and the specific work being done at the Johnson Space Center and DARPA in developing optical correlator technology

Optical joint correlator for real-time image tracking and retinal surgery

A method for tracking an object in a sequence of images is described. Such sequence of images may, for example, be a sequence of television frames. The object in the current frame is correlated with the object in the previous frame to obtain the relative location of the object in the two frames. An optical joint transform correlator apparatus is provided to carry out the process. Such joint transform correlator apparatus forms the basis for laser eye surgical apparatus where an image of the fundus of an eyeball is stabilized and forms the basis for the correlator apparatus to track the position of the eyeball caused by involuntary movement. With knowledge of the eyeball position, a surgical laser can be precisely pointed toward a position on the retina

Two dimensional vernier

A two-dimensional vernier scale is disclosed utilizing a cartesian grid on one plate member with a polar grid on an overlying transparent plate member. The polar grid has multiple concentric circles at a fractional spacing of the spacing of the cartesian grid lines. By locating the center of the polar grid on a location on the cartesian grid, interpolation can be made of both the X and Y fractional relationship to the cartesian grid by noting which circles coincide with a cartesian grid line for the X and Y direction

Programmable remapper for image processing

A video-rate coordinate remapper includes a memory for storing a plurality of transformations on look-up tables for remapping input images from one coordinate system to another. Such transformations are operator selectable. The remapper includes a collective processor by which certain input pixels of an input image are transformed to a portion of the output image in a many-to-one relationship. The remapper includes an interpolative processor by which the remaining input pixels of the input image are transformed to another portion of the output image in a one-to-many relationship. The invention includes certain specific transforms for creating output images useful for certain defects of visually impaired people. The invention also includes means for shifting input pixels and means for scrolling the output matrix

Misregistration's effects on classification and proportion estimation accuracy

The estimates of crop type and acreage are undertaken in the AgRISTARS program by registering multiple date acquisitions of small subareas of LANDSAT scenes (termed segments), and applying multispectral analysis to them. An important contribution to errors in classification and acreage estimates is misregistration between multiple acquisitions. The formula used to express this relationship is given and the operations applied are so shown in diagrams. The taking of a LANDSAT feature vector and the derivation of the brightness and greeness are illustrated. It is shown that for any given sensor IFOV geometry, typical populations of fields can be derived and histograms can be plotted of the number of fields against field size according to ground truth. As a function of the resolution element, the IFOV of the sensor can draw the proportion of pure pixels in a given crop. Because the thematic mapper has a smaller resolution, the proportion of pixels that are pure in any given area will be larger

A maximal chromatic expansion method of mapping multichannel imagery into color space

The author has identified the following significant results. A color film generation method that maximally expands the chromaticity and aligns Kauth brightness with the gray axis was presented. In comparison with the current LACIE film product, the new color film product has more contrast and more colors and appears to be brighter. The field boundaries in the new product were more pronounced than in the current LACIE product. The speckle effect was one problem in the new product. The yellowness speckle can be treated using an equation. This equation can be used to eliminate any speckle introduced by the greenness. This product leads logically toward another that will employ quantitative colorimetry which will account for some of the eye's perception of color stimuli

AFES Misc. Pub. 98–1

This publication is the fourth in the Alaska RNA series, and the first published by the University of Alaska Fairbanks.The 65 ha Big Windy Hot Springs Research Natural Area (RNA) in the Steese National Conservation Area of central Alaska is managed by the Bureau of Land Management. It contains a vent that issues hot water at about 61° C flowing at about 8 liters per minute from the largest of a system of small springs and seeps. Geothermal water seeping over the face of a cliff has intensely weathered the local granitic bedrock into gruss. The fracture of massive boulders from the possibly fault-related cliff is one of the most distinctive features of the RNA. Small boulders from the cliff have fallen into Big Windy Creek where they have been caught in the swirling current of Big Windy Creek and ground potholes into the bed of the high-gradient stream. Big Windy Creek is constricted to a narrow canyon. The main geothermal pools are lined with thermophytic algal and cyanobacteria mats. Undescribed high-temperature aquatic species may be present. geothermal heat in the vicinity of the main vents promotes a lush growth of vegetation including Phalaris arundinacea and Ranunculus cymbalaria, two species that occur here north of their previously reported distribution in Alaska. The RNA contains contrasting north- and south-facing canyon slopes. Diffuse geothermal heating of soil around the vents is associated with a large and productive mature white spruce forest on the south-facing slope. A paper birch forest with a minor white spruce component covers most of the south-facing slope. The north-facing slope is underlain with permafrost; areas of boulder talus are subjected to periglacial weathering processes. Low paper birch forest, black spruce woodland, and dwarf birch tundra provide the main vegetation cover. The lowland east-central Alaska region has experienced a strong climate warming trend since the late 1970s. Radial growth of white spruce at Big Windy Hot Springs is generally negatively related to summer temperature. The Big Windy Hot Spring site is a mineral lick heavily used by a local population of Dall sheep that roam from nearby alpine habitats into the RNA. A collection of the water shrew (Sorex palustris) in the RNA is several hundred km from other known populations and is the new northern limit for the species in North America.This work was partially supported by the Macintire-Stennis Cooperative Forestry Research Program and grants to the Agricultural and Forestry Experiment Station, University of Alaska Fairbanks from the Bureau of Land Management, U.S. Department of the Interior.Introduction -- Access and Accommodations : Structures and Trails ; Parking, Roads and Rights-of-way -- Reasons for Establishing the Research Natural Area -- Environment : Climate ; Geology ; Soils -- Biota : Vegetation ; Fauna -- History of Disturbance and Future Conditions -- Management Direction -- Research -- metric and English Units of Measure -- Reference

Spatial light modulators for full cross-connections in optical networks

A polarization-independent optical switch is disclosed for switching at least one incoming beam from at least one input source to at least one output drain. The switch includes a polarizing beam splitter to split each of the at least one incoming beam into a first input beam and a second input beam, wherein the first input beam and the second input beams are independently polarized; a wave plate optically coupled to the second input beam for converting the polarization of the second input beam to an appropriately polarized second input beam; a beam combiner optically coupled to the first input beam and the modified second input beam, wherein the beam combiner accepts the first input beam and the modified second input beam to produce a combined beam; the combined beam is invariant to the polarization state of the input source's polarization; and a controllable spatial light modulator optically coupled to the combined beam, wherein the combined beam is diffracted by the controllable spatial light modulator to place light at a plurality of output locations

Spatial Light Modulators as Optical Crossbar Switches

A proposed method of implementing cross connections in an optical communication network is based on the use of a spatial light modulator (SLM) to form controlled diffraction patterns that connect inputs (light sources) and outputs (light sinks). Sources would typically include optical fibers and/or light-emitting diodes; sinks would typically include optical fibers and/or photodetectors. The sources and/or sinks could be distributed in two dimensions; that is, on planes. Alternatively or in addition, sources and/or sinks could be distributed in three dimensions -- for example, on curved surfaces or in more complex (including random) three-dimensional patterns