Gary B. Hughes Copyright (c) 2011 All rights reserved. http://works.bepress.com/gbhughes Recent documents in Gary B. Hughes en-us Sun, 04 Sep 2011 01:46:51 PDT 3600 Automated Systems and Methods for Testing Infrared Cameras http://works.bepress.com/gbhughes/20 http://works.bepress.com/gbhughes/20 Fri, 02 Sep 2011 11:37:21 PDT Systems and methods are disclosed herein to provide automated testing on infrared image data to detect image quality defects. For example, in accordance with an embodiment of the present invention, image processing algorithms are disclosed to generate an image quality metric that may be compared to one or more thresholds to perform an automated test for image quality defects. For example, the image quality metric may be compared to two thresholds to determine if the corresponding infrared sensor or infrared camera is defective or not due to image quality or requires further manual inspection by test personnel.

]]> Gary B. Hughes Patents Radiometric Clocks http://works.bepress.com/gbhughes/19 http://works.bepress.com/gbhughes/19 Thu, 28 Jan 2010 13:28:25 PST This paper provides and introduction to radioactivity, and how geologists exploit radioactive decay to determine the age of rocks.

]]> Gary B. Hughes Unpublished Papers Puerto Rico Rainfall http://works.bepress.com/gbhughes/18 http://works.bepress.com/gbhughes/18 Thu, 28 Jan 2010 11:38:29 PST In Earth science research, climatic conditions can have significant effects on dynamic processes. For example, the growth of forests is affected by temperature, rainfall and other climatic variables. However, these climate parameters are rarely measured at the forest stands whose growth is being investigated. The climate conditions are measured at nearby weather stations, though, and it is a common approach to use the weather station data to ‘predict’ the climate at the study site

]]> Gary B. Hughes Unpublished Papers Calculating Ellipse Overlap Areas http://works.bepress.com/gbhughes/17 http://works.bepress.com/gbhughes/17 Tue, 25 Aug 2009 17:01:51 PDT We present a general algorithm for finding the overlap area between two ellipses. The algorithm is based on finding a segment area (the area between an ellipse and a secant line) given two points on the ellipse. The Gauss-Green formula is used to determine the ellipse sector area between two points, and a triangular area is added or subtracted to give the segment area. For two ellipses, overlap area is calculated by adding the areas of appropriate sectors and polygons. Intersection points for two general ellipses are found using Ferrari's quartic formula to solve the polynomial that results from combining the two ellipse equations. All cases for the number of intersection points (0, 1, 2, 3, 4) are handled. The algorithm is implemented in c-code, and has been tested with a range of input ellipses. The code is efficient enough for use in simulations that require many overlap area calculations.

]]> Gary B. Hughes et al. Unpublished Papers Electrical Feedthrough and Its Preparation http://works.bepress.com/gbhughes/16 http://works.bepress.com/gbhughes/16 Tue, 25 Aug 2009 16:51:18 PDT An electrical feedthrough (34) is prepared by furnishing an aluminum oxide feedthrough plate (70) and at least one feedthrough pin (80) having a length greater than the thickness of the feedthrough plate (70). A pin bore (78) is formed through the feedthrough plate (70) for each feedthrough pin (80). Each pin bore (78) has a pin bore (78) size greater than the feedthrough pin (80) size, preferably by an amount no greater than that required to permit the penetration of a brazing metal (88) between the pin bore (78) and the feedthrough pin (80). Each feedthrough pin (80) is inserted into its respective pin bore (78) and brazed into place utilizing a metallic active braze alloy (88) and no glassy seal. The feedthrough plate (70) may be simultaneously brazed to a package structure (22) using active or nonactive brazing.

]]> Leonard E. Peck et al. Patents Semi-permanent vacuum closure with multiple retubulation capability http://works.bepress.com/gbhughes/15 http://works.bepress.com/gbhughes/15 Tue, 25 Aug 2009 16:51:17 PDT A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough, a hollow tube (62) fixed to the base (50) with a vacuum-tight seal, such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50), and an external thread (58) on the exterior of the base (50). The external thread (58) on the exterior of the base (50) is dimensioned to threadably engage the internal thread (68) on the aperture (66). There is a disengageable vacuum sealant (70) such as a layer of indium metal between the external thread (58) of the base (50) and the internal thread (68) of the aperture (66). The vacuum system (20) is evacuated through the tip-off fitting (24) and sealed by closing off the hollow tube (62). At a later time, the vacuum system can be brought to atmospheric pressure and then reseated by replacing the tip-off fitting with another tip-off fitting and repeating the evacuation and sealing.

]]> Arthur A. Eneim et al. Patents Brazed Lower Vacuum Housing for a Dewar http://works.bepress.com/gbhughes/14 http://works.bepress.com/gbhughes/14 Tue, 25 Aug 2009 16:51:17 PDT A lower vacuum housing (34) of a sensor dewar (26) is fabricated in a single brazing operation from ceramic and metallic components. The components are assembled with ceramic-to-metal interfaces and metal-to-metal interfaces. Brazing is accomplished by active brazing of the ceramic-to-metal interfaces and non-active brazing of the metal-to-metal interfaces. Specific combinations of active braze alloys and non-active braze alloys are provided for various combinations of dewar materials.

]]> Timothy S. Romano et al. Patents Fabrication Method for Adhesive Pressure Bonding Two Components Together with Closed-Loop Control http://works.bepress.com/gbhughes/13 http://works.bepress.com/gbhughes/13 Tue, 25 Aug 2009 16:51:16 PDT Two components are bonded together in a bonding apparatus using a bonding medium of malleable metallic spheres and a curable adhesive. The two components are bonded by positioning the components in a facing-but-spaced-apart relation in the bonding apparatus with the spheres and the adhesive between the first component and the second component. The bonding apparatus forces the first component toward the second component with sufficient force to bond the spheres to the first component and to the second component, while monitoring at least one measured bonding reaction of the first component and the second component, and controlling the bonding apparatus responsive to the step of monitoring. The adhesive is thereafter cured, optionally with the bonding pressure released and the assembly removed from the bonding apparatus.

]]> Gary B. Hughes et al. Patents Feedthrough pin and process for its preparation, and electrical feedthrough made therewith http://works.bepress.com/gbhughes/12 http://works.bepress.com/gbhughes/12 Tue, 25 Aug 2009 16:51:16 PDT A feedthrough (34) is formed of a feedthrough plate (44) having at least one bore (46) therethrough and a feedthrough pin (48) hermetically sealed into the bore (46). The feedthrough pin (48) includes an elongated pin (50) having an axis of elongation (52), a recess (54) in at least one end of the pin (50), the recess (54) extending parallel to the axis of elongation (52), and a gold coating (56) within the recess (54). There are preferably a plurality of bores (46) in the feedthrough plate (48) and a corresponding plurality of the feedthrough pins (48). The gold coatings (56) at the ends of the feedthrough pins (48) are desirably lapped to ensure coplanarity and a smooth surface finish especially suited for wire bonding or tab bonding.

]]> Timothy S. Romano et al. Patents Preparation of gold-coated molybdenum articles and articles prepared thereby http://works.bepress.com/gbhughes/11 http://works.bepress.com/gbhughes/11 Tue, 25 Aug 2009 16:51:15 PDT A gold-coated molybdenum article (30) is made by furnishing a substrate (32) made of pure molybdenum or an alloy of molybdenum, and preparing a slurry of gold powder, acrylic binder, and acetone liquid carrier. The slurry is applied to a portion of a surface of the substrate. The substrate with applied slurry is heated in vacuum or inert atmosphere to an elevated temperature, preferably about 2040.degree. F., and thereafter cooled to ambient temperature. The result is an article (30) having at least a portion of the substrate (32) covered with an adherent gold coating (34).

]]> Timothy S. Romano et al. Patents Modern Spectral Climate Patterns in Rhythmically Deposited Argillites of the Gowganda Formation (Early Proterozoic), Southern Ontario, Canada http://works.bepress.com/gbhughes/10 http://works.bepress.com/gbhughes/10 Tue, 25 Aug 2009 15:54:12 PDT Rhythmically deposited argillites of the Gowganda Formation (ca. 2.0–2.5 Ga) probably formed in a glacial setting. Drop stones and layered sedimentary couplets in the rock presumably indicate formation in a lacustrine environment with repeating freeze–thaw cycles. It is plausible that temporal variations in the thickness of sedimentary layers are related to interannual climatic variability, e.g. average seasonal temperature could have influenced melting and the amount of sediment source material carried to the lake. A sequence of layer couplet thickness measurements was made from high-resolution digitized photographs taken at an outcrop in southern Ontario, Canada. The frequency spectrum of thickness measurements displays patterns that resemble some aspects of modern climate. Coherent periodic modes in the thickness spectrum appear at 9.9–10.7 layer couplets and at 14.3 layer couplets. It is unlikely that these coherent modes result from random processes. Modern instrument records of regional temperature and rainfall display similar spectral patterns, with some datasets showing significant modes near 14 yr in both parameters. Rainfall and temperature could have affected sedimentary layering in the Gowganda argillite sequence, and climate modulation of couplet thickness emerges as the most likely explanation of the observed layering pattern. If this interpretation is correct, the layer couplets represent predominantly annual accumulations of sediment (i.e. they are varves), and the thickness spectrum provides a glimpse of Early Proterozoic climatic variability. The presence of interannual climate patterns is not unanticipated, but field evidence presented here may be of some value in developing a climate theory for the Early Proterozoic.

]]> Gary B. Hughes et al. Articles Sclerosponges: Potential High-Resolution Recorders of Marine Paleotemperatures http://works.bepress.com/gbhughes/9 http://works.bepress.com/gbhughes/9 Tue, 25 Aug 2009 15:54:12 PDT Sclerosponges have great potential as seawater temperature recorders. These animals precipitate their skeletons in carbon and oxygen isotopic equilibrium with the surrounding seawater (Druffel and Benavides, 1986). Their skeletons also display chemical properties that vary directly with changes in environmental conditions. Lack of photosynthetic symbionts allows sclerosponges to live below the photic zone, providing the potential to investigate past marine conditions beyond the range of corals. Individual sponges live for several centuries, preserving archives of pre-and postindustrial seawater variations within single specimens (Hartman and Reiswig, 1980). Cross-correlation of successively older specimens could yield up to 2000 years of marine history. Extracting environmental information can be accomplished by determining elemental characteristics preserved in skeletal growth bands. A method is presented here that utilizes energy dispersive spectroscopy (EDS) to provide inexpensive assessment of magnesium (Mg): calcium (Ca) and chlorine (Cl): calcium (Ca) ratios at high spatial resolution, yielding environmental data with correspondingly high temporal resolution. The relationship between environmental conditions and skeletal characteristics is defined by a spectral transfer function, which can then be applied to skeletal carbonate data from ancient sponges to reconstruct past environmental conditions. Accurate reconstruction of seawater temperature and salinity variations is demonstrated here at sub-monthly resolution. The technique's efficiency is ideal for documenting long, high-resolution records of marine paleoenvironments.

]]> Gary B. Hughes et al. Book Chapters Additional Algorithms for Sensor Chip Alignment to Blind Datums http://works.bepress.com/gbhughes/7 http://works.bepress.com/gbhughes/7 Tue, 25 Aug 2009 15:54:11 PDT Alignment of the sensor focal plane array (FPA) to optical components is a critical design feature. Imaging system designs include reference datums that provide the basis for manufacturing alignment in each sub-assembly. Measurement of z and parallelism positioning can be problematic, since the relevant datum features are often beneath the mounting platform and are obscured to the measurement system. General algorithms for determining sensor chip alignment when datum features are inaccessible to the measurement system have been developed. Pre-characterization measurements of datum surfaces are stored for later use during alignment measurement to determine datum locations. The algorithms are useful for post-mounting alignment measurement, and can also be used for active manufacturing alignment. This paper presents additional algorithms that are useful for active alignment, including methods for determining rotation axes on the aligner-bonder system and for determining actuator motions to bring the FPA into alignment with datums. The algorithms have been successfully implemented for ultra-precision, active manufacturing alignment and post-alignment measurement of infrared imaging systems.

]]> Gary B. Hughes Conference Proceedings Latest Tools for Viewing and Quality Checking ARM Data http://works.bepress.com/gbhughes/8 http://works.bepress.com/gbhughes/8 Tue, 25 Aug 2009 15:54:11 PDT The DOE Atmospheric Radiation Measurement (ARM) program has acquired an incredibly large quantity of data over its period of operation, all of which must be reviewed in some manner in order to ensure that the data is of “known and reasonable” quality (ARM Science Plan). To accomplish this, Mission Research Corporation (MRC) coordinates with the ARM Data Quality Office to develop software tools that quality-check data products in a timely and continuous fashion. These tools work with the Data Quality Health and Status (DQ HandS) Explorer (Peppler et al. 2004) by analyzing ARM data streams, providing assessments of data quality in the form of color-coded tables, and generating custom visualizations.

Tools for interactively visualizing ARM data sets have also been developed by us for inspecting each of the 600+ data streams that pass through the ARM Data Management Facility (DMF) each day. NCVweb is a Web based application developed for this task, and is designed to allow easy access to ARM data at the DMF and at the ARM archive.

Here we will review some of NCVweb’s key features as well as introduce new tools for viewing the quality of Atmospheric Emitted Radiance Interferometer (AERI) data, its corresponding Value Added Products (VAPs) and Quality Measurement Experiments (QMEs).

]]> S. Moore et al. Conference Proceedings Algorithms for Sensor Chip Alignment to Blind Datums http://works.bepress.com/gbhughes/6 http://works.bepress.com/gbhughes/6 Tue, 25 Aug 2009 15:54:10 PDT The sensor element of an imaging system should be mounted into its housing in such a way that the scene can be properly focused onto the sensor element's focal plane over the active area. Operational imaging requirements are forcing increasingly smaller tolerances on sensor alignment, and manufacturing systems must improve alignment capability to keep pace. Imaging system designs include reference datums that provide the basis for manufacturing alignment of optical components in each subassembly. Design constraints for alignment of the sensor element into the camera housing typically include x,y,z, clocking, and parallelism specifications. Measurement of z and parallelism positioning is often problematic, since the relevant reference datum features are often beneath the mounting platform and are obscured to the measurement system. General algorithms for determining sensor chip alignment when datum features are inaccessible to the measurement system are described. Precharacterization measurements of datum surfaces are used to determine datum locations during alignment measurement. The algorithms are useful for active manufacturing alignment as well as postmounting alignment measurement. The algorithms are successfully implemented for ultraprecision, active manufacturing alignment, and postalignment measurement of IR imaging systems.

]]> Gary B. Hughes Articles Improvements To and Status of the Data Quality Health and Status System http://works.bepress.com/gbhughes/5 http://works.bepress.com/gbhughes/5 Tue, 25 Aug 2009 15:54:10 PDT The Atmospheric Radiation Measurement (ARM) Data Quality Office (DQO) has made a number of improvements and additions over the past year to its main tool for inspecting and assessing ARM data quality—the Data Quality Health and Status (DQ HandS) system (http://dq.arm.gov/). Among the improvements and additions, some of which are shown below, are the inclusion of ARM Mobile Facility (AMF) data; a new plot browser to facilitate the viewing of DQ HandS diagnostic plots; an improved method for writing and databasing weekly data quality assessment reports; a new automated daily alert, an improved method for searching ARM report databases (see Doty and Wagener’s abstract in this proceeding); addition of more instrument and value-added products output, and creation of a development version of DQ HandS that allows the present system to become a true production tool.

]]> K. Kehoe et al. Conference Proceedings Extensive Forest Leaf Area Survey Aiming at Detection of Vegetation Change in Subarctic-Boreal Zone http://works.bepress.com/gbhughes/4 http://works.bepress.com/gbhughes/4 Tue, 25 Aug 2009 15:54:09 PDT The warming resulting from increasing anthropogenic carbon dioxide and other greenhouse gasses is expected to be most prominent in the subarctic-boreal region of the Northern Hemisphere. With the objective of setting up a baseline to monitor possible vegetation change in this region, a continuous vegetation profile extending 600 km from Edmonton, Alberta to Cluff Lake, Saskatchewan, Canada was measured using an airborne infrared laser altimeter mounted on a helicopter. Then the distribution of leaf area index over the same 600 km long transect was estimated from this vegetation profile based on a series of plot surveys on the ground to correlate the vegetation profile with leaf area index via standing stock. The distribution of leaf area index not only corresponded well with biome type, but also showed characteristic change in accordance with environmental gradient within a given biome, thus confirming that airborne laser altimetry is a powerful tool for measuring and monitoring such important vegetation characteristics as standing volume, leaf area index, etc. over an extensive area.

]]> Tomoko Kusakabe et al. Articles Instrument Cross-Comparisons and Automated Quality Control of Atmospheric Radiation Measurement Data http://works.bepress.com/gbhughes/1 http://works.bepress.com/gbhughes/1 Tue, 25 Aug 2009 15:54:08 PDT Within the Atmospheric Radiation Measurement (ARM) instrument network, several different systems often measure the same quantity at the same site. For example, several ARM instruments measure time-series profiles of the atmosphere that were previously available only from balloon-borne radiosonde systems. These instruments include the Radar Wind Profilers (RWP) with Radio-Acoustic Sounding Systems (RASS), the Atmospheric Emitted Radiance Interferometer (AERI), the Microwave Radiometer Profiler (MWRP), and the Raman Lidar (RL). ARM researchers have described methods for direct cross-comparison of time-series profiles (Coulter and Lesht 1996; Turner et al. 1996) and we have extended this concept to the development of methods for automated quality control (QC) of ARM datastreams.

]]> S. Moore et al. Conference Proceedings Numeric issues in test software correctness http://works.bepress.com/gbhughes/2 http://works.bepress.com/gbhughes/2 Tue, 25 Aug 2009 15:54:08 PDT Test system designers are comfortable with the concepts of precision and accuracy with regard to measurements achieved with modern instrumentation. In a well-designed test system, great care is taken to ensure accurate measurements, with rigorous attention to instrument specifications and calibration. However, measurement values are subjected to representation and manipulation as limited precision floating-point numbers by test software. This paper investigates some of the issues related to floating point representation of measurement values, as well as the consequences of algorithm selection. To illustrate, we consider the test case of standard deviation calculations as used in the testing of infrared focal plane arrays. We consider the concept of using statistically-based techniques for selection of an appropriate algorithm based on measurement values, and offer guidelines for the proper expression and manipulation of measurement values within popular test software programming frameworks.

]]> Robert G. Hayes et al. Conference Proceedings