Abstract: Interferometric transform spectrometer (ITS) systems and methods of operation thereof. In one example, an ITS system includes a Michelson interferometer that introduces a varying optical path length difference (OPD) between its two arms so as to produce an interferogram, a detector that receives and samples the interferogram, and a scan controller coupled to the detector and to Michelson interferometer. The scan controller controls the Michelson interferometer to vary the OPD in discrete steps such that the detector provides M samples of the interferogram for each of two scan segments. In the first scan segment, the M samples have a uniform or non-uniform sample spacing and the OPD has a first maximum value. In the second scan segment, the M samples have an incrementally increasing sample spacing and the OPD has a second maximum value that is at least twice the first maximum value.

Abstract: A rapid anomaly detection approach with corresponding method and system to detect anomalies in scene pixels making up a hyperspectral scene, efficiently, is presented. The approach includes tailoring an approximation of an anomaly score for each scene pixel, individually, based on an “intermediate anomaly score.” The intermediate score is computed using a portion of the terms used to compute the anomaly score. Scene pixels with low intermediate anomaly scores are removed from further processing. The remaining scene pixels are further processed, including computing anomaly scores to detect anomalies in these pixels. Advantageously, examples of the RAND approach process a few terms of all scene pixels, eliminate most scene pixels, and calculate more terms on high anomaly scoring scene pixels as needed.

Abstract: A rapid anomaly detection approach with corresponding method and system to detect anomalies in scene pixels making up a hyperspectral scene, efficiently, is presented. The approach includes tailoring an approximation of an anomaly score for each scene pixel, individually, based on an “intermediate anomaly score.” The intermediate score is computed using a portion of the terms used to compute the anomaly score. Scene pixels with low intermediate anomaly scores are removed from further processing. The remaining scene pixels are further processed, including computing anomaly scores to detect anomalies in these pixels. Advantageously, examples of the RAND approach process a few terms of all scene pixels, eliminate most scene pixels, and calculate more terms on high anomaly scoring scene pixels as needed.

Abstract: A method includes generating a sampling signal having a non-uniform sampling interval and sampling a received signal with an analog-to-digital converter (ADC) using the sampling signal. The method also includes mapping the sampled received signal onto a frequency grid of sinusoids, where each sinusoid has a signal amplitude and a signal phase. The method further includes estimating the signal amplitude and the signal phase for each sinusoid in the frequency grid. In addition, the method includes computing an average background power level and detecting signals with power higher than the average background power level. The non-uniform sampling interval varies predictably.

Abstract: In accordance with various aspects of the disclosure, a system, a method, and computer readable medium having instructions for processing images is disclosed. For example, the method includes receiving, at an image processor, a set of images corresponding to a scene changing with time, decomposing, at the image processor, the set of images to detect static objects, leaner objects, and mover objects in the scene, the mover objects being objects that change spatial orientation in the scene with time, and compressing, using the image processor, the mover objects in the scene separately at a rate different from that of the static objects and the leaner objects for storage and/or transmission.

Abstract: Interferometric transform spectrometer (ITS) systems and methods of operation thereof. In one example, an ITS system includes a Michelson interferometer that introduces a varying optical path length difference (OPD) between its two arms so as to produce an interferogram, a detector that receives and samples the interferogram, and a scan controller coupled to the detector and to Michelson interferometer. The scan controller controls the Michelson interferometer to vary the OPD in discrete steps such that the detector provides M samples of the interferogram for each of two scan segments. In the first scan segment, the M samples have a uniform or non-uniform sample spacing and the OPD has a first maximum value. In the second scan segment, the M samples have an incrementally increasing sample spacing and the OPD has a second maximum value that is at least twice the first maximum value.

Abstract: The disclosure provides a filtering engine for selecting a subset of hyperspectral imaging wavebands having information useful for detecting a target in a scene. Selecting these wavebands, called “sparse bands,” is an iterative process. One or more search techniques of varying computational complexity are used in the process. The techniques rely on various selection criteria, including a signal to clutter ratio that measures the “goodness” of band selection. A convenient example of the filtering engine uses several of the techniques together in a layered approach. In this novel approach, simpler computational techniques are applied, initially, to reduce a number of bands. More computationally intensive techniques then search the reduced band space. Accordingly, the filtering engine efficiently selects a set of sparse bands tailored for each target and each scene, and maintains some of the detection capability provided with a full set of wavebands.

Abstract: A rapid target detection approach with corresponding method and system to detect targets in scene pixels, efficiently, is presented. The approach includes tailoring an approximation of a target score for each scene pixel, individually, based on an “intermediate target score.” The intermediate target score includes a portion of the terms used to compute the target score. The portion is selected by computing a signal-to-clutter ratio (SCR) for a spectral reference associated with a target and ranking the terms by their contribution to the SCR. Scene pixels with low intermediate target scores are removed from further processing. The remaining scene pixels are further processed, including computing target scores to detect targets in these scene pixel. Advantageously, examples of the approach process a few terms of all scene pixels, eliminate most scene pixels, and calculate more terms on high target scoring scene pixels as needed.

Abstract: Provided are examples of a detecting engine for determining in which pixels in a hyperspectral scene are materials of interest or targets present. A collection of spectral references, typically five to a few hundred, is used in look a through a million or more pixels per scene to identify detections. An example of the detecting engine identifies detections by calculating a kernel vector for each spectral reference in the collection. This calculation is quicker than the conventional Matched Filter kernel calculation which computes a kernel for each scene pixel. Another example of the detecting engine selects pixels with high detection filter scores and calculates coherence scores for these pixels. This calculation is more efficient than the conventional Adaptive Cosine/Coherence Estimator calculation that calculates a score for each scene pixel, most of which do not provide a detection.

Abstract: Provided are examples of a detecting engine for identifying detections in compressed scene pixels. For a given compressed scene pixel having a set of M basis vector coefficients, set of N basis vectors, and code linking the M basis vector coefficients to the N basis vectors, the detecting engine reduces a spectral reference (S) to an N-dimensional spectral reference (SN) based on the set of N basis vectors. The detecting engine computes an N-dimensional spectral reference detection filter (SN*) from SN and the inverse of an N-dimensional scene covariance (CN). The detecting engine forms an M-dimensional spectral reference detection filter (SM*) from SN* based on the compression code and computes a detection filter score based on SM*. The detecting engine compares the score to a threshold and determines, based on the comparison, whether the material of interest is present in the given compressed scene pixel and is a detection.

Abstract: Computer implemented methods for compressing 3D hyperspectral image data having a plurality of spatial pixels associated with a hyperspectral image, and a number of spectral dimensions associated with each spatial pixel, include receiving, using a processor, the 3D hyperspectral image data, a set of basis vectors associated therewith, and either a maximum error amount or a maximum data size. The methods also include partitioning the 3D hyperspectral image data into a plurality of 2D images, each associated with one of the number of spectral dimensions, and an associated one of the set of basis vectors. The methods additionally include ranking the set of basis vectors if not already ranked. The methods may further include iteratively applying lossy compression to the 2D images, in an order determined by the ranking. Other embodiments and features are also disclosed.

Abstract: In accordance with various aspects of the disclosure, a detecting engine for detecting targets/materials in hyperspectral scenes is disclosed. The detecting engine combines data partitioning and dimensionality reduction to reduce the number of computations needed to identify in which pixels in a hyperspectral scene a given material is present. Computation reduction (in some instances, by two fold) greatly impacts the speed of and power consumed by the detecting engine making the engine suitable for hyperspectral imaging of large scenes, processing using many filters per pixel, or missions requiring testing large numbers of reference spectra to see which are present in a scene.

Abstract: In accordance with various aspects of the disclosure, a system, a method, and computer readable medium having instructions for processing images is disclosed. For example, the method includes receiving an input datacube from which an input image is derived. The input datacube is transformed into a residual datacube by projecting out basis vectors from each spatial pixel in the input datacube, the residual datacube being used to derive a residual image. A statistical parameter value for samples of each focal plane pixel in the residual image is determined. Anomalous focal plane pixels are identified based upon a comparison of the determined statistical parameter value with the respective determined statistical parameter values of remaining focal plane pixels. Another comparison of residual values for each scanned sample of the identified anomalous focal plane pixels with values of corresponding scanned samples in the input datacube is performed.

Abstract: The disclosure provides a filtering engine for selecting sparse filter components used to detect a material of interest (or specific target) in a hyperspectral imaging scene and applying the sparse filter to a plurality of pixels in the scene. The filtering engine transforms a spectral reference representing the material of interest to principal components space using the eigenvectors of the scene. It then ranks sparse filter components based on each transformed component of the spectral reference. The filtering engine selects sparse filter components based on their ranks. The filtering engine performs the subset selection quickly because the computations are minimized; it processes only the spectral reference vector and covariance matrix of the scene to do the subset selection rather than process a plurality of pixels in the scene, as is typically done. The spectral filter scores for the plurality of pixels are calculated efficiently using the sparse filter.

Abstract: Provided are examples of a detecting engine for identifying detections in compressed scene pixels. For a given compressed scene pixel having a set of M basis vector coefficients, set of N basis vectors, and code linking the M basis vector coefficients to the N basis vectors, the detecting engine reduces a spectral reference (S) to an N-dimensional spectral reference (SN) based on the set of N basis vectors. The detecting engine computes an N-dimensional spectral reference detection filter (SN*) from SN and the inverse of an N-dimensional scene covariance (CN). The detecting engine forms an M-dimensional spectral reference detection filter (SM*) from SN* based on the compression code and computes a detection filter score based on SM*. The detecting engine compares the score to a threshold and determines, based on the comparison, whether the material of interest is present in the given compressed scene pixel and is a detection.

Abstract: The disclosure provides a filtering engine for selecting sparse filter components used to detect a material of interest (or specific target) in a hyperspectral imaging scene and applying the sparse filter to a plurality of pixels in the scene. The filtering engine transforms a spectral reference representing the material of interest to principal components space using the eigenvectors of the scene. It then ranks sparse filter components based on each transformed component of the spectral reference. The filtering engine selects sparse filter components based on their ranks. The filtering engine performs the subset selection quickly because the computations are minimized; it processes only the spectral reference vector and covariance matrix of the scene to do the subset selection rather than process a plurality of pixels in the scene, as is typically done. The spectral filter scores for the plurality of pixels are calculated efficiently using the sparse filter.

Abstract: A method for reducing dimensionality of hyperspectral images includes receiving a hyperspectral image having a plurality of pixels. The method may further include establishing an orthonormal basis vector set comprising a plurality of mutually orthogonal normalized members. Each of the mutually orthogonal normalized members may be associated with one of the plurality of pixels of the hyperspectral image. The method may further include decomposing the hyperspectral image into a reduced dimensionality image, utilizing calculations performed while establishing said orthonormal basis vector set. A system configured to perform the method may also be provided.

Abstract: Provided is a process and system for detection of sparse or otherwise weak targets in a hyperspectral image. A hyperspectral image is received having a multitude of pixels, with each pixel having a respective spectrum. In some embodiments, multiple mean spectra are selectively determined for respective sub-regions of the hyperspectral image. The subset mean spectra can be selectively removed from respective pixels, thereby improving image fidelity due to sensor artifacts. Additionally, target detection of such an adjusted image can be determined by one or more of matched filter techniques or by partial un-mixing. In at least some embodiments target detection is enhanced by combining a measure of target match with a residual spectrum determined as a measure of un-match. Target detection can be further improved by application of rules, for example, related to target detection threshold.

Abstract: Provided is a process and system for detection of sparse or otherwise weak targets in a hyperspectral image. A hyperspectral image is received having a multitude of pixels, with each pixel having a respective spectrum. In some embodiments, multiple mean spectra are selectively determined for respective sub-regions of the hyperspectral image. The subset mean spectra can be selectively removed from respective pixels, thereby improving image fidelity due to sensor artifacts. Additionally, target detection of such an adjusted image can be determined by one or more of matched filter techniques or by partial un-mixing. In at least some embodiments target detection is enhanced by combining a measure of target match with a residual spectrum determined as a measure of un-match. Target detection can be further improved by application of rules, for example, related to target detection threshold.

Abstract: Provided are examples of a detecting engine for determining in which pixels in a hyperspectral scene are materials of interest or targets present. A collection of spectral references, typically five to a few hundred, is used in look a through a million or more pixels per scene to identify detections. An example of the detecting engine identifies detections by calculating a kernel vector for each spectral reference in the collection. This calculation is quicker than the conventional Matched Filter kernel calculation which computes a kernel for each scene pixel. Another example of the detecting engine selects pixels with high detection filter scores and calculates coherence scores for these pixels. This calculation is more efficient than the conventional Adaptive Cosine/Coherence Estimator calculation that calculates a score for each scene pixel, most of which do not provide a detection.