Abstract: A text and imagery spatial correlator automatically relates the geographic locations where events referenced in text occur to those same geographic locations appearing in imagery. In the preferred embodiment, the system deploys adaptable, context-sensitive agents for the automatic interpretation of text, and the application of those agents to classify and geolocate textual references. The results are integrated with similar spatial references from imagery in a common data model, accessible by both spatial and non-spatial data correlation. The unique combination of elements enables the system to automatically develop spatial relationships between text and imagery. Although the invention finds utility in numerous applications, the system and method are particularly useful in correlating remote sensor imagery.

Abstract: An expandable trailer is designed for transportation and use of satellite communication related electronic equipment. The trailer has a generally horizontal support frame with an upper surface defining a floor of the trailer. A pair of spaced apart generally vertical side walls extend upwardly from the support frame and define an interior transport area between the walls. An expansion module is supported in an opening in one of the side walls. The expansion module has a vertical front panel and rear panel with inboard edges and outboard edges. The panels are spaced apart to define the front and rear of the expansion module. A generally vertical side panel extends between the outboard edges of the front and rear panels and has an upper edge and a lower edge.

Abstract: Techniques to modify and apply aerogel coatings are described, including the application of spray-coated aerogels. The approach eliminates several of the wet chemical techniques previously needed for processes such as MALDI processing, and simplifies the automation of processes such as continuous monitoring in a sensor based format. With respect to MALDI processing, the preferred embodiment uses an acid-doped silica aerogel coated tape as the collection media as well as the matrix support. Although aerogels are disclosed as a preferred matrix material, other materials may alternatively be used, including linoleic acids, oleic acids, PEG (polyelthylene glycol), preferably in tape format.

Abstract: A tracking system uses a miniaturized geographic position determination and communications module, preferably in the form of a thin capsule, enabling the enclosure to be hidden in very small spaces, including personal concealment. Electronic circuitry and a thin, rechargeable battery are contained within the enclosure, the circuitry including a global positioning satellite receiver, a communications transceiver, and a controller. The controller causes the global positioning satellite receiver to receive and decode a signal relating to the geographic position of the module; cause the communications transmitter to communicate the geographic position information to a remote location; and disable the global positioning satellite receiver and communications transceiver when not in use so as to conserve power.

Abstract: A system and method for sensing phase errors in a multiple receiver array use three non-collinear transmitters transmitting first, second, and third signals to a target and receiving corresponding signals reflected from the target using the multiple receiver array. In one embodiment, each transmitter transmits a characteristic signal which can be distinguished from each other by the receivers. In one embodiment, each transmitter transmits a slightly different monotone frequency that is preferably outside any imaging bandwidth. The sheared products computed from heterodyne measurements at the receivers in the array based on the reflected signals from the three transmitters are used to determine and correct for the combined transmitter/receiver phase errors at each of the receivers in the array.

Abstract: An expandable trailer is designed for transportation and use of satellite communication related electronic equipment. The trailer has a generally horizontal support frame with an upper surface defining a floor of the trailer. A pair of spaced apart generally vertical side walls extend upwardly from the support and define an interior transport area between the walls. An expansion module is supported in an opening in one of the side walls. The expansion module has a vertical front panel and rear panel with inboard edges and outboard edges. The panels are spaced apart to define the front and rear of the expansion module. A generally vertical side panel extends between the outboard edges of the front and rear panels and has an upper edge and a lower edge. The expansion module has a closed position where the side panel is generally aligned with the side wall and the outboard edges of the front and rear panels are adjacent the side wall.

Abstract: Variational calculus principles are applied directly to the radiation integral to minimize the radar signature of a two- or three-dimensional geometry. In the preferred embodiment, the radiation integral is minimized through the solution to a differential equation generated by Euler's calculus of variations (CoV) equation. When used in conjunction with a minimizing sequence, the analysis affords a broad search of all possible coefficient values to ultimately arrive at global minima. Compared to existing techniques, the approach locates local extrema quickly and accurately using fewer impedance matrix calculations, and optimization using the invention is possible over a wide band of frequencies and angles. The method is applicable to a wide variety of situations, including the design of stealth platforms.

Abstract: A system assists the driver of a motor vehicle to travel within a designated driving lane defined by one or more lane boundaries. The lane boundary is sensed as the vehicle moves within the lane while monitoring the position of the vehicle relative to the lane boundary. The operation of the vehicle is then adjusted as a function of the proximity of the vehicle to the lane boundary. In one embodiment, the operation of the vehicle is affected by adjusting the functioning of the steering wheel, preferably by providing tactile feedback which causes the driver to experience a virtual change in lane elevation as the vehicle approaches the lane boundary. In the preferred embodiment, the tactile feedback causes the vehicle operator to experience the lane as having a depression with sloping sidewalls. Where the lane boundaries are defined by visual lane markers, the lane-boundary sensor preferably takes the form of a video camera to image the lane markers.

Abstract: A reference-based autofocusing procedure is particularly suited to existing and future interferometric SAR systems, though the principles are generally applicable to signal processing systems for which there are two partially correlated data sets having relative spectral errors. In an airborne or spaceborne system, the technique only requires some additional steps in the ground processor functions. The invention takes advantage of the fact that in a bistatic system, one antenna phase center both transmits and receives with the usual common-mode cancellation, and can thus be expected to form a reasonably well-focused image. In the second system, with the degraded phase error response, the image provided by the first system is used as a coherent reference to aid the estimation and removal of the relative phase errors between the two.

Abstract: A tracking system uses a miniaturized geographic position determination and communications module, preferably in the form of a thin capsule, enabling the enclosure to be hidden in very small spaces, including personal concealment. Electronic circuitry and a thin, rechargeable battery are contained within the enclosure, the circuitry including a global positioning satellite receiver, a communications transceiver, and a controller. The controller causes the global positioning satellite receiver to receive and decode a signal relating to the geographic position of the module; cause the communications transmitter to communicate the geographic position information to a remote location; and disable the global positioning satellite receiver and communications transceiver when not in use so as to conserve power.

Abstract: A method of minimizing leakage energy in a synthetic aperture radar (SAR) system is based a Lagrangian function constructed from image-domain magnitude, and a "penalty function" based upon the choice of aperture. Broadly, the choice of penalty function is related to an estimate of undesirable energy lying outside of the main lobe of the impulse response introduced by the given aperture. Since there are no non-analytic constraints, the output image is purely an analytic function of the input, resulting in a more straightforward analysis and implementation while lessening the likelihood of pseudo-random phenomena. A tunable relative coefficient betveen the sidelobe energy estimate and the output magnitude allows control over a physically well-understood tradeoff between clutter contrast and point resolution. The generality of the technique may be extended to a multi-parameter minimization with possible applications in super-resolution, gap-filling, interferometry, and ultrasonic imaging, and ATR.

Abstract: A method of phase unwrapping is described along with an efficient UNIX/C implementation. From selected reference or starting points in a phase-wrapped image, the phase gradients with respect to the nearest neighbors of the starting pixels whose correlation is above the first correlation threshold are examined and a path representing the smallest phase difference is chosen as the first step in the creation of a path. The process is continued and, with each step, a maximum of three new neighbors is added to a list of possible path extensions. The list is sorted by step size, and the smallest step size is selected as the next path extension. This continues until all pixels that can be reached by paths containing only pixels with correlation above the first correlation threshold are on a path. In the same way, the paths are then extended to include all pixels with correlation above the next lower correlation threshold.

Abstract: A hand-held instrument provides a simple and elegant approach to determining the presence or absence of a surface condition such as roughening. A light source such as a laser diode illuminates a localized area of the surface to be characterized, and a light-sensitive detector is supported to receive light reflected by the surface and generate an electrical signal representative of the light received. An optical blocking element is placed at a first point along the axis of the reflected light, and a focussing lens is placed at a second point along the axis. If the surface is smooth or not sufficiently roughened, light is reflected substantially along the axis and blocked by the element so it does not reach the detector. If the surface is roughened, however, the reflected light is scattered off-axis and focussed by the lens onto the detector, thereby effectively bypassing the blocking element.

Abstract: A method for determining a range dimension of an object utilizing multiple wavelength interferometry to form an image of the object includes developing a discernible two-dimensional image from an interference pattern at selected points for each of a number of wavelengths, collecting complex values from the interference pattern and developing a phase value from the complex value, and determining a phase correction vector based on a difference between measured phase values and an ideal phase value associated with one or more reference points. The phase correction vector is used to correct each of the selected points. A one-dimensional Fourier transform is performed on the corrected values to yield a range profile for each selected point. A peak value is then determined from the range profile to determine the range dimension. The peak value may be determined based on a simple maximum, oversampling in selected areas prior to performing the Fourier transform, or using curve-fitting techniques.

Abstract: A system for interferometric inspection of an object includes a number of improvements to reduce spurious reflections and provide precision measurement of large objects. A neutral density filter of absorptive glass is used as an attenuator to reduce undesirable reflections which may otherwise result in detector saturation. A wedge-shaped beam splitter having at least one anti-reflective surface is also utilized to reduce unwanted reflections. The system uses multiple wavelength interferometry to provide range information for an object. Additional improvements in precision may be provided by using a wavelength calibration device such as an etalon, a wavemeter, or a reference cell having relatively narrow transmission peaks, to improve the accuracy in determining the laser wavelengths. The wavelength information may be used to more precisely determine range values for the object.

Abstract: A collision avoidance system for a vehicle of the type having a powered lift mechanism with a lift control used to move the mechanism between a predetermined safe position and an elevated position includes a first sensor to determine whether the mechanism is in the safe or the elevated position, and a second sensor used to determine whether an operator is using the lift control to power the mechanism beyond the safe position. If the mechanism is in the elevated position and the operator is not using the lift control to power the mechanism beyond the safe position, control electronics are operative to automatically transfer the mechanism from the elevated position back to the safe position without operator intervention. Means may be provided for alerting an operator of the vehicle when the mechanism is in the elevated position, for example, in the form of an intermittent, periodic audible and/or visual indicator which continues until the mechanism is brought back to the safe position.

Abstract: A method of performing the computer-intensive initial steps of the range migration algorithm, or RMA, produces radar imagery of higher quality than the current polar format (PF) processing approach, while operating faster and more efficiently than the standard RMA. The new method is advantageous when the synthetic aperture length required to achieve azimuth resolution is significantly larger than the azimuth extent of the processed scene. The method subdivides the signal history into a plurality of non-overlapping subapertures, adds a low bandwidth azimuth chirp across each subaperture and applies a fast Fourier transform separately to each subaperture. The results are coherently combined, after which the remaining steps of the conventional RMA may be completed with minor modifications to the subsequent two-dimensional phase compensation. The invention is applicable to spotlight, stripmap and scan-mode SAR image formation, and the separate, subaperture Fourier transformations may be performed simultaneously.

Abstract: A method for determining a range dimension of an object utilizing multiple wavelength interferometry to form an image of the object includes developing a discernible two-dimensional image from an interference pattern at selected points for each of a number of wavelengths, collecting complex values from the interference pattern and developing a phase value from the complex value, and determining a phase correction vector based on a difference between measured phase values and an ideal phase value associated with one or more reference points. The phase correction vector is used to correct each of the selected points. A one-dimensional Fourier transform is performed on the corrected values to yield a range profile for each selected point. A peak value is then determined from the range profile to determine the range dimension. The peak value may be determined based on a simple maximum, oversampling in selected areas prior to performing the Fourier transform, or using curve-fitting techniques.

Abstract: An image recognition and classification system includes a preprocessor in which a "top-down" method is used to extract features from an image; an associative learning neural network system, which groups the features into patterns and classifies the patterns: and a feedback mechanism which improves system performance by tuning preprocessor scale, feature detection, and feature selection.

Abstract: A high-order synthetic aperture radar (SAR) autofocusing method decomposes phase error into basis function components, one order at a time. Image patches are partitioned into a plurality of subapertures in accordance with positive- and negative-going slope of the basis function at each order. A positive mask is applied to each subaperture within which the basis function is increasing in slope, whereas a negative mask is applied to each subaperture within which the basis function is decreasing in slope. The results are then correlated to obtain a focused image, with the principle of map-drift preferably being used to compute phase-amplitude weights. The method may be uniformly applied, enabling the steps to be performed at a plurality of increasingly higher orders without performance degradation.