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Sample records for multisensor array processing

  1. Multisensor Arrays for Greater Reliability and Accuracy

    NASA Technical Reports Server (NTRS)

    Immer, Christopher; Eckhoff, Anthony; Lane, John; Perotti, Jose; Randazzo, John; Blalock, Norman; Ree, Jeff

    2004-01-01

    Arrays of multiple, nominally identical sensors with sensor-output-processing electronic hardware and software are being developed in order to obtain accuracy, reliability, and lifetime greater than those of single sensors. The conceptual basis of this development lies in the statistical behavior of multiple sensors and a multisensor-array (MSA) algorithm that exploits that behavior. In addition, advances in microelectromechanical systems (MEMS) and integrated circuits are exploited. A typical sensor unit according to this concept includes multiple MEMS sensors and sensor-readout circuitry fabricated together on a single chip and packaged compactly with a microprocessor that performs several functions, including execution of the MSA algorithm. In the MSA algorithm, the readings from all the sensors in an array at a given instant of time are compared and the reliability of each sensor is quantified. This comparison of readings and quantification of reliabilities involves the calculation of the ratio between every sensor reading and every other sensor reading, plus calculation of the sum of all such ratios. Then one output reading for the given instant of time is computed as a weighted average of the readings of all the sensors. In this computation, the weight for each sensor is the aforementioned value used to quantify its reliability. In an optional variant of the MSA algorithm that can be implemented easily, a running sum of the reliability value for each sensor at previous time steps as well as at the present time step is used as the weight of the sensor in calculating the weighted average at the present time step. In this variant, the weight of a sensor that continually fails gradually decreases, so that eventually, its influence over the output reading becomes minimal: In effect, the sensor system "learns" which sensors to trust and which not to trust. The MSA algorithm incorporates a criterion for deciding whether there remain enough sensor readings that

  2. Highly reliable multisensor array (MSA) smart transducers

    NASA Astrophysics Data System (ADS)

    Perotti, José; Lucena, Angel; Mackey, Paul; Mata, Carlos; Immer, Christopher

    2006-05-01

    Many developments in the field of multisensor array (MSA) transducers have taken place in the last few years. Advancements in fabrication technology, such as Micro-Electro-Mechanical Systems (MEMS) and nanotechnology, have made implementation of MSA devices a reality. NASA Kennedy Space Center (KSC) has been developing this type of technology because of the increases in safety, reliability, and performance and the reduction in operational and maintenance costs that can be achieved with these devices. To demonstrate the MSA technology benefits, KSC quantified the relationship between the number of sensors (N) and the associated improvement in sensor life and reliability. A software algorithm was developed to monitor and assess the health of each element and the overall MSA. Furthermore, the software algorithm implemented criteria on how these elements would contribute to the MSA-calculated output to ensure required performance. The hypothesis was that a greater number of statistically independent sensor elements would provide a measurable increase in measurement reliability. A computer simulation was created to answer this question. An array of N sensors underwent random failures in the simulation and a life extension factor (LEF equals the percentage of the life of a single sensor) was calculated by the program. When LEF was plotted as a function of N, a quasiexponential behavior was detected with marginal improvement above N = 30. The hypothesis and follow-on simulation results were then corroborated experimentally. An array composed of eight independent pressure sensors was fabricated. To accelerate sensor life cycle and failure and to simulate degradation over time, the MSA was exposed to an environmental tem-perature of 125°C. Every 24 hours, the experiment's environmental temperature was returned to ambient temperature (27°C), and the outputs of all the MSA sensor elements were measured. Once per week, the MSA calibration was verified at five different

  3. Toward new gas-analytical multisensor chips based on titanium oxide nanotube array.

    PubMed

    Fedorov, Fedor; Vasilkov, Michail; Lashkov, Andrey; Varezhnikov, Alexey; Fuchs, Dirk; Kübel, Christian; Bruns, Michael; Sommer, Martin; Sysoev, Victor

    2017-08-29

    Reliable environmental monitoring requires cost effective but highly sensitive and selective gas sensors. While the sensitivity of the sensors is improved by reducing the characteristic dimensions of the gas-sensing material, the selectivity is often approached by combining the sensors into multisensor arrays. The development of scalable methods to manufacture such arrays based on low-dimensional structures offers new perspectives for gas sensing applications. Here we examine an approach to produce multisensor array chips based on the TiOx nanotube layers segmented by multiple Pt strip electrodes. We study the sensitivity and selectivity of the developed chip at operating temperatures up to 400 °C towards organic vapors in the ppm range. The results indicate that the titania nanotubes are a promising material platform for novel cost-effective and powerful gas-analytical multisensor units.

  4. Hybrid integration process for the development of multisensor chips

    NASA Astrophysics Data System (ADS)

    Jin, Na; Liu, Weiguo

    A novel hybrid integration process had been developed for the integration of single crystal pyroelectric detector with readout IC based on a thinning and anisotropic conduction tape bonding technique. We report our recent progress in applying the hybrid integration process for the fabrication of a multisensor chip with thermal and sound detectors integrated. The sound detector in the multisensor chip is based on thinned single crystal quartz, while the thermal detector in the chip is making use of thinned PLZT ceramic wafer. A membrane transfer process (MTP) was applied for the thinning and integration of the single crystal and ceramic wafers.

  5. Robust site security using smart seismic array technology and multi-sensor data fusion

    NASA Astrophysics Data System (ADS)

    Hellickson, Dean; Richards, Paul; Reynolds, Zane; Keener, Joshua

    2010-04-01

    Traditional site security systems are susceptible to high individual sensor nuisance alarm rates that reduce the overall system effectiveness. Visual assessment of intrusions can be intensive and manually difficult as cameras are slewed by the system to non intrusion areas or as operators respond to nuisance alarms. Very little system intrusion performance data are available other than discrete sensor alarm indications that provide no real value. This paper discusses the system architecture, integration and display of a multi-sensor data fused system for wide area surveillance, local site intrusion detection and intrusion classification. The incorporation of a novel seismic array of smart sensors using FK Beamforming processing that greatly enhances the overall system detection and classification performance of the system is discussed. Recent test data demonstrates the performance of the seismic array within several different installations and its ability to classify and track moving targets at significant standoff distances with exceptional immunity to background clutter and noise. Multi-sensor data fusion is applied across a suite of complimentary sensors eliminating almost all nuisance alarms while integrating within a geographical information system to feed a visual-fusion display of the area being secured. Real-time sensor detection and intrusion classification data is presented within a visual-fusion display providing greatly enhanced situational awareness, system performance information and real-time assessment of intrusions and situations of interest with limited security operator involvement. This approach scales from a small local perimeter to very large geographical area and can be used across multiple sites controlled at a single command and control station.

  6. Breath analysis system for early detection of lung diseases based on multi-sensor array

    NASA Astrophysics Data System (ADS)

    Jeon, Jin-Young; Yu, Joon-Boo; Shin, Jeong-Suk; Byun, Hyung-Gi; Lim, Jeong-Ok

    2013-05-01

    Expiratory breath contains various VOCs(Volatile Organic Compounds) produced from the human. When a certain disease exists, the exhalation has specific VOCs which may be generated from diseases. Many researchers have been actively working to find different types of biomarkers which are characteristic for particular diseases. Research regarding the identification of specific diseases from exhalation is still in progress. The aim of this research is to implement early detection of lung disease such as lung cancer and COPD(Chronic Obstructive Pulmonary Disease), which was nominated on the 6th of domestic death rate in 2010, based on multi-sensor array system. The system has been used to acquire sampled expiratory gases data and PCA(Principle Component Analysis) technique was applied to analyze signals from multi-sensor array. Throughout the experimental trials, a clearly distinguishable difference between lung disease patients and healthy controls was found from the measurement and analysis of their respective expiratory gases.

  7. Could We Apply a NeuroProcessor For Analyzing a Gas Response Of Multisensor Arrays?

    SciTech Connect

    Sysoev, V. V.; Musatov, V. Yu.; Maschenko, A. A.; Varegnikov, A. S.; Chrizostomov, A. A.; Kiselev, I.; Schneider, T.; Bruns, M.; Sommer, M.

    2009-05-23

    We describe an effort of implementation of hardware neuroprocessor to carry out pattern recognition of signals generated by a multisensor microarray of Electronic Nose type. The multisensor microarray is designed with the SnO{sub 2} thin film segmented by co-planar electrodes according to KAMINA (KArlsruhe Micro NAse) E-nose architecture. The response of this microarray to reducing gases mixtured with a synthetic air is processed by principal component analysis technique realized in PC (Matlab software) and the neural microprocessor NeuroMatrix NM6403. It is shown that the neuroprocessor is able to successfully carry out a gas-recognition algorithm at a real-time scale.

  8. AprilTag array-aided extrinsic calibration of camera-laser multi-sensor system.

    PubMed

    Tang, Dengqing; Hu, Tianjiang; Shen, Lincheng; Ma, Zhaowei; Pan, Congyu

    This paper presents a new algorithm for extrinsically calibrating a multi-sensor system including multiple cameras and a 2D laser scanner. On the basis of the camera pose estimation using AprilTag, we design an AprilTag array as the calibration target and employ a nonlinear optimization to calculate the single-camera extrinsic parameters when multiple tags are in the field of view of the camera. The extrinsic parameters of camera-camera and laser-camera are then calibrated, respectively. A global optimization is finally used to refine all the extrinsic parameters by minimizing a re-projection error. This algorithm is adapted to the extrinsic calibration of multiple cameras even if there is non-overlapping field of view. For algorithm validation, we have built a micro-aerial vehicle platform with multi-sensor system to collect real data, and the experiment results confirmed that the proposed algorithm yields great performance.

  9. A Radiosonde Using a Humidity Sensor Array with a Platinum Resistance Heater and Multi-Sensor Data Fusion

    PubMed Central

    Shi, Yunbo; Luo, Yi; Zhao, Wenjie; Shang, Chunxue; Wang, Yadong; Chen, Yinsheng

    2013-01-01

    This paper describes the design and implementation of a radiosonde which can measure the meteorological temperature, humidity, pressure, and other atmospheric data. The system is composed of a CPU, microwave module, temperature sensor, pressure sensor and humidity sensor array. In order to effectively solve the humidity sensor condensation problem due to the low temperatures in the high altitude environment, a capacitive humidity sensor including four humidity sensors to collect meteorological humidity and a platinum resistance heater was developed using micro-electro-mechanical-system (MEMS) technology. A platinum resistance wire with 99.999% purity and 0.023 mm in diameter was used to obtain the meteorological temperature. A multi-sensor data fusion technique was applied to process the atmospheric data. Static and dynamic experimental results show that the designed humidity sensor with platinum resistance heater can effectively tackle the sensor condensation problem, shorten response times and enhance sensitivity. The humidity sensor array can improve measurement accuracy and obtain a reliable initial meteorological humidity data, while the multi-sensor data fusion technique eliminates the uncertainty in the measurement. The radiosonde can accurately reflect the meteorological changes. PMID:23857263

  10. A radiosonde using a humidity sensor array with a platinum resistance heater and multi-sensor data fusion.

    PubMed

    Shi, Yunbo; Luo, Yi; Zhao, Wenjie; Shang, Chunxue; Wang, Yadong; Chen, Yinsheng

    2013-07-12

    This paper describes the design and implementation of a radiosonde which can measure the meteorological temperature, humidity, pressure, and other atmospheric data. The system is composed of a CPU, microwave module, temperature sensor, pressure sensor and humidity sensor array. In order to effectively solve the humidity sensor condensation problem due to the low temperatures in the high altitude environment, a capacitive humidity sensor including four humidity sensors to collect meteorological humidity and a platinum resistance heater was developed using micro-electro-mechanical-system (MEMS) technology. A platinum resistance wire with 99.999% purity and 0.023 mm in diameter was used to obtain the meteorological temperature. A multi-sensor data fusion technique was applied to process the atmospheric data. Static and dynamic experimental results show that the designed humidity sensor with platinum resistance heater can effectively tackle the sensor condensation problem, shorten response times and enhance sensitivity. The humidity sensor array can improve measurement accuracy and obtain a reliable initial meteorological humidity data, while the multi-sensor data fusion technique eliminates the uncertainty in the measurement. The radiosonde can accurately reflect the meteorological changes.

  11. Optical sensors and multisensor arrays containing thin film electroluminescent devices

    DOEpatents

    Aylott, Jonathan W.; Chen-Esterlit, Zoe; Friedl, Jon H.; Kopelman, Raoul; Savvateev, Vadim N.; Shinar, Joseph

    2001-12-18

    Optical sensor, probe and array devices for detecting chemical biological, and physical analytes. The devices include an analyte-sensitive layer optically coupled to a thin film electroluminescent layer which activates the analyte-sensitive layer to provide an optical response. The optical response varies depending upon the presence of an analyte and is detected by a photodetector and analyzed to determine the properties of the analyte.

  12. Multi-sensor Array for High Altitude Balloon Missions to the Stratosphere

    NASA Astrophysics Data System (ADS)

    Davis, Tim; McClurg, Bryce; Sohl, John

    2008-10-01

    We have designed and built a microprocessor controlled and expandable multi-sensor array for data collection on near space missions. Weber State University has started a high altitude research balloon program called HARBOR. This array has been designed to data log a base set of measurements for every flight and has room for six guest instruments. The base measurements are absolute pressure, on-board temperature, 3-axis accelerometer for attitude measurement, and 2-axis compensated magnetic compass. The system also contains a real time clock and circuitry for logging data directly to a USB memory stick. In typical operation the measurements will be cycled through in sequence and saved to the memory stick along with the clock's time stamp. The microprocessor can be reprogrammed to adapt to guest experiments with either analog or digital interfacing. This system will fly with every mission and will provide backup data collection for other instrumentation for which the primary task is measuring atmospheric pressure and temperature. The attitude data will be used to determine the orientation of the onboard camera systems to aid in identifying features in the images. This will make these images easier to use for any future GIS (geographic information system) remote sensing missions.

  13. Multisensor network system for wildfire detection using infrared image processing.

    PubMed

    Bosch, I; Serrano, A; Vergara, L

    2013-01-01

    This paper presents the next step in the evolution of multi-sensor wireless network systems in the early automatic detection of forest fires. This network allows remote monitoring of each of the locations as well as communication between each of the sensors and with the control stations. The result is an increased coverage area, with quicker and safer responses. To determine the presence of a forest wildfire, the system employs decision fusion in thermal imaging, which can exploit various expected characteristics of a real fire, including short-term persistence and long-term increases over time. Results from testing in the laboratory and in a real environment are presented to authenticate and verify the accuracy of the operation of the proposed system. The system performance is gauged by the number of alarms and the time to the first alarm (corresponding to a real fire), for different probability of false alarm (PFA). The necessity of including decision fusion is thereby demonstrated.

  14. Array signal processing

    SciTech Connect

    Haykin, S.; Justice, J.H.; Owsley, N.L.; Yen, J.L.; Kak, A.C.

    1985-01-01

    This is the first book to be devoted completely to array signal processing, a subject that has become increasingly important in recent years. The book consists of six chapters. Chapter 1, which is introductory, reviews some basic concepts in wave propagation. The remaining five chapters deal with the theory and applications of array signal processing in (a) exploration seismology, (b) passive sonar, (c) radar, (d) radio astronomy, and (e) tomographic imaging. The various chapters of the book are self-contained. The book is written by a team of five active researchers, who are specialists in the individual fields covered by the pertinent chapters.

  15. Multisensor Network System for Wildfire Detection Using Infrared Image Processing

    PubMed Central

    Bosch, I.; Serrano, A.; Vergara, L.

    2013-01-01

    This paper presents the next step in the evolution of multi-sensor wireless network systems in the early automatic detection of forest fires. This network allows remote monitoring of each of the locations as well as communication between each of the sensors and with the control stations. The result is an increased coverage area, with quicker and safer responses. To determine the presence of a forest wildfire, the system employs decision fusion in thermal imaging, which can exploit various expected characteristics of a real fire, including short-term persistence and long-term increases over time. Results from testing in the laboratory and in a real environment are presented to authenticate and verify the accuracy of the operation of the proposed system. The system performance is gauged by the number of alarms and the time to the first alarm (corresponding to a real fire), for different probability of false alarm (PFA). The necessity of including decision fusion is thereby demonstrated. PMID:23843734

  16. Cellular Array Processing Simulation

    NASA Astrophysics Data System (ADS)

    Lee, Harry C.; Preston, Earl W.

    1981-11-01

    The Cellular Array Processing Simulation (CAPS) system is a high-level image language that runs on a multiprocessor configuration. CAPS is interpretively decoded on a conventional minicomputer with all image operation instructions executed on an array processor. The synergistic environment that exists between the minicomputer and the array processor gives CAPS its high-speed throughput, while maintaining a convenient conversational user language. CAPS was designed to be both modular and table driven so that it can be easily maintained and modified. CAPS uses the image convolution operator as one of its primitives and performs this cellular operation by decomposing it into parallel image steps that are scheduled to be executed on the array processor. Among its features is the ability to observe the imagery in real time as a user's algorithm is executed. This feature reduces the need for image storage space, since it is feasible to retain only original images and produce resultant images when needed. CAPS also contains a language processor that permits users to develop re-entrant image processing subroutines or algorithms.

  17. Identification and quantification of individual volatile organic compounds in a binary mixture by SAW multisensor array and pattern recognition analysis

    NASA Astrophysics Data System (ADS)

    Penza, M.; Cassano, G.; Tortorella, F.

    2002-06-01

    We have developed a surface acoustic wave (SAW) multisensor array with five acoustic sensing elements configured as two-port resonator 433.92 MHz oscillators and a reference SAW element to recognize different individual components and determine their concentrations in a binary mixture of volatile organic compounds (VOCs) such as methanol and acetone, in the ranges 15-130 and 50-250 ppm, respectively. The SAW sensors have been specifically coated by various sensing thin films such as arachidic acid, carbowax, behenic acid, triethanolamine or acrylated polysiloxane, operating at room temperature. By using the relative frequency change as the output signal of the SAW multisensor array with an artificial neural network (ANN), a recognition system has been realized for the identification and quantification of tested VOCs. The features of the SAW multisensor array exposed to a binary component organic mixture of methanol and acetone have been extracted from the output signals of five SAW sensors by pattern recognition (PARC) techniques, such as principal component analysis (PCA). An organic vapour pattern classifier has been implemented by using a multilayer neural network with a backpropagation learning algorithm. The normalized responses of a reduced set of SAW sensors or selected principal components scores have been used as inputs for a feed-forward multilayer perceptron (MLP), resulting in a 70% correct recognition rate with the normalized responses of the four SAW sensors and in an enhanced 80% correct recognition rate with the first two principal components of the original data consisting of the normalized responses of the four SAW sensors. The prediction of the individual vapour concentrations has been tackled with PCA for features extraction and by using the first two principal components scores as inputs to a feed-forward MLP consisting of a gating network, which decides which of three specific subnets should be used to determine the output concentration: the

  18. Multi-sensor data processing method for improved satellite retrievals

    NASA Astrophysics Data System (ADS)

    Fan, Xingwang

    2017-04-01

    calibration and its comparison with regression approaches. IEEE Transactions on Geoscience and Remote Sensing, 55(3), doi: 10.1109/TGRS.2016.2635802.]. These studies demonstrate the success of multi-sensor data and novel methods in the research domain of geoscience. These data will benefit remote sensing of terrestrial parameters in decadal timescales, such as soil salinity content in Fan et al. (2016) [Fan, X., Weng, Y., and Tao, J. (2016). Towards decadal soil salinity mapping using Landsat time series data. International Journal of Applied Earth Observation and Geoinformation, 52, 32-41.].

  19. Spatiotemporal properties of auditory intensity processing in multisensor MEG.

    PubMed

    Wyss, C; Boers, F; Kawohl, W; Arrubla, J; Vahedipour, K; Dammers, J; Neuner, I; Shah, N J

    2014-11-15

    Loudness dependence of auditory evoked potentials (LDAEP) evaluates loudness processing in the human auditory system and is often altered in patients with psychiatric disorders. Previous research has suggested that this measure may be used as an indicator of the central serotonergic system through the highly serotonergic innervation of the auditory cortex. However, differences among the commonly used analysis approaches (such as source analysis and single electrode estimation) may lead to different results. Putatively due to discrepancies of the underlying structures being measured. Therefore, it is important to learn more about how and where in the brain loudness variation is processed. We conducted a detailed investigation of the LDAEP generators and their temporal dynamics by means of multichannel magnetoencephalography (MEG). Evoked responses to brief tones of five different intensities were recorded from 19 healthy participants. We used magnetic field tomography in order to appropriately localize superficial as well as deep source generators of which we conducted a time series analysis. The results showed that apart from the auditory cortex other cortical sources exhibited activation during the N1/P2 time window. Analysis of time courses in the regions of interest revealed a sequential cortical activation from primary sensory areas, particularly the auditory and somatosensory cortex to posterior cingulate cortex (PCC) and to premotor cortex (PMC). The additional activation within the PCC and PMC has implications on the analysis approaches used in LDAEP research. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Atomic Magnetometer Multisensor Array for rf Interference Mitigation and Unshielded Detection of Nuclear Quadrupole Resonance

    NASA Astrophysics Data System (ADS)

    Cooper, Robert J.; Prescott, David W.; Matz, Peter; Sauer, Karen L.; Dural, Nezih; Romalis, Michael V.; Foley, Elizabeth L.; Kornack, Thomas W.; Monti, Mark; Okamitsu, Jeffrey

    2016-12-01

    An array of four 87Rb vector magnetometers is used to detect nuclear quadrupole resonance signals in an unshielded environment at 1 MHz. With a baseline of 25 cm, the length of the array, radio-frequency interference mitigation is also demonstrated; a radio-station signal is suppressed by a factor of 20 without degradation to the signal of interest. With these compact sensors, in which the probe beam passes through twice, the fundamental limit to detection sensitivity is found to be photon-shot noise. More passes of the probe beam overcome this limitation. With a sensor of similar effective volume, 0.25 cm3 , but 25 × more passes, the sensitivity is improved by an order of magnitude to 1.7 ±0.2 fT /√{Hz } .

  1. Metal oxide based multisensor array and portable database for field analysis of antioxidants

    PubMed Central

    Sharpe, Erica; Bradley, Ryan; Frasco, Thalia; Jayathilaka, Dilhani; Marsh, Amanda; Andreescu, Silvana

    2014-01-01

    We report a novel chemical sensing array based on metal oxide nanoparticles as a portable and inexpensive paper-based colorimetric method for polyphenol detection and field characterization of antioxidant containing samples. Multiple metal oxide nanoparticles with various polyphenol binding properties were used as active sensing materials to develop the sensor array and establish a database of polyphenol standards that include epigallocatechin gallate, gallic acid, resveratrol, and Trolox among others. Unique charge-transfer complexes are formed between each polyphenol and each metal oxide on the surface of individual sensors in the array, creating distinct optically detectable signals which have been quantified and logged into a reference database for polyphenol identification. The field-portable Pantone/X-Rite© CapSure® color reader was used to create this database and to facilitate rapid colorimetric analysis. The use of multiple metal-oxide sensors allows for cross-validation of results and increases accuracy of analysis. The database has enabled successful identification and quantification of antioxidant constituents within real botanical extractions including green tea. Formation of charge-transfer complexes is also correlated with antioxidant activity exhibiting electron transfer capabilities of each polyphenol. The antioxidant activity of each sample was calculated and validated against the oxygen radical absorbance capacity (ORAC) assay showing good comparability. The results indicate that this method can be successfully used for a more comprehensive analysis of antioxidant containing samples as compared to conventional methods. This technology can greatly simplify investigations into plant phenolics and make possible the on-site determination of antioxidant composition and activity in remote locations. PMID:24610993

  2. Metal oxide based multisensor array and portable database for field analysis of antioxidants.

    PubMed

    Sharpe, Erica; Bradley, Ryan; Frasco, Thalia; Jayathilaka, Dilhani; Marsh, Amanda; Andreescu, Silvana

    2014-03-31

    We report a novel chemical sensing array based on metal oxide nanoparticles as a portable and inexpensive paper-based colorimetric method for polyphenol detection and field characterization of antioxidant containing samples. Multiple metal oxide nanoparticles with various polyphenol binding properties were used as active sensing materials to develop the sensor array and establish a database of polyphenol standards that include epigallocatechin gallate, gallic acid, resveratrol, and Trolox among others. Unique charge-transfer complexes are formed between each polyphenol and each metal oxide on the surface of individual sensors in the array, creating distinct optically detectable signals which have been quantified and logged into a reference database for polyphenol identification. The field-portable Pantone/X-Rite© CapSure® color reader was used to create this database and to facilitate rapid colorimetric analysis. The use of multiple metal-oxide sensors allows for cross-validation of results and increases accuracy of analysis. The database has enabled successful identification and quantification of antioxidant constituents within real botanical extractions including green tea. Formation of charge-transfer complexes is also correlated with antioxidant activity exhibiting electron transfer capabilities of each polyphenol. The antioxidant activity of each sample was calculated and validated against the oxygen radical absorbance capacity (ORAC) assay showing good comparability. The results indicate that this method can be successfully used for a more comprehensive analysis of antioxidant containing samples as compared to conventional methods. This technology can greatly simplify investigations into plant phenolics and make possible the on-site determination of antioxidant composition and activity in remote locations.

  3. Data Processing for Noninvasive Continuous Glucose Monitoring with a Multisensor Device

    PubMed Central

    Mueller, Martin; Talary, Mark S; Falco, Lisa; De Feo, Oscar; Stahel, Werner A; Caduff, Andreas

    2011-01-01

    Background: Impedance spectroscopy has been shown to be a candidate for noninvasive continuous glucose monitoring in humans. However, in addition to glucose, other factors also have effects on impedance characteristics of the skin and underlying tissue. Method: Impedance spectra were summarized through a principal component analysis and relevant variables were identified with Akaike's information criterion. In order to model blood glucose, a linear least-squares model was used. A Monte Carlo simulation was applied to examine the effects of personalizing models. Results: The principal component analysis was able to identify two major effects in the impedance spectra: a blood glucose-related process and an equilibration process related to moisturization of the skin and underlying tissue. With a global linear least-squares model, a coefficient of determination (R2) of 0.60 was achieved, whereas the personalized model reached an R2 of 0.71. The Monte Carlo simulation proved a significant advantage of personalized models over global models. Conclusion: A principal component analysis is useful for extracting glucose-related effects in the impedance spectra of human skin. A linear global model based on Solianis Multisensor data yields a good predictive power for blood glucose estimation. However, a personalized linear model still has greater predictive power. PMID:21722585

  4. Integrated multisensor navigation systems

    NASA Technical Reports Server (NTRS)

    Vangraas, Frank

    1988-01-01

    The multisensor navigation systems research evolved from the availability of several stand alone navigation systems and the growing concern for aircraft navigation reliability and safety. The intent is to develop a multisensor navigation system during the next decade that will be capable of providing reliable aircraft position data. These data will then be transmitted directly, or by satellite, to surveillance centers to aid the process of air traffic flow control. In order to satisfy the requirements for such a system, the following issues need to be examined: performance, coverage, reliability, availability, and integrity. The presence of a multisensor navigation system in all aircraft will improve safety for the aviation community and allow for more economical operation.

  5. Multi-sensor fusion development

    NASA Astrophysics Data System (ADS)

    Bish, Sheldon; Rohrer, Matthew; Scheffel, Peter; Bennett, Kelly

    2016-05-01

    The U.S. Army Research Laboratory (ARL) and McQ Inc. are developing a generic sensor fusion architecture that involves several diverse processes working in combination to create a dynamic task-oriented, real-time informational capability. Processes include sensor data collection, persistent and observational data storage, and multimodal and multisensor fusion that includes the flexibility to modify the fusion program rules for each mission. Such a fusion engine lends itself to a diverse set of sensing applications and architectures while using open-source software technologies. In this paper, we describe a fusion engine architecture that combines multimodal and multi-sensor fusion within an Open Standard for Unattended Sensors (OSUS) framework. The modular, plug-and-play architecture of OSUS allows future fusion plugin methodologies to have seamless integration into the fusion architecture at the conceptual and implementation level. Although beyond the scope of this paper, this architecture allows for data and information manipulation and filtering for an array of applications.

  6. Distributed multisensor processing, decision making, and control under constrained resources for remote health and environmental monitoring

    NASA Astrophysics Data System (ADS)

    Talukder, Ashit; Sheikh, Tanwir; Chandramouli, Lavanya

    2004-04-01

    Previous field-deployable distributed sensing systems for health/biomedical applications and environmental sensing have been designed for data collection and data transmission at pre-set intervals, rather than for on-board processing These previous sensing systems lack autonomous capabilities, and have limited lifespans. We propose the use of an integrated machine learning architecture, with automated planning-scheduling and resource management capabilities that can be used for a variety of autonomous sensing applications with very limited computing, power, and bandwidth resources. We lay out general solutions for efficient processing in a multi-tiered (three-tier) machine learning framework that is suited for remote, mobile sensing systems. Novel dimensionality reduction techniques that are designed for classification are used to compress each individual sensor data and pass only relevant information to the mobile multisensor fusion module (second-tier). Statistical classifiers that are capable of handling missing/partial sensory data due to sensor failure or power loss are used to detect critical events and pass the information to the third tier (central server) for manual analysis and/or analysis by advanced pattern recognition techniques. Genetic optimisation algorithms are used to control the system in the presence of dynamic events, and also ensure that system requirements (i.e. minimum life of the system) are met. This tight integration of control optimisation and machine learning algorithms results in a highly efficient sensor network with intelligent decision making capabilities. The applicability of our technology in remote health monitoring and environmental monitoring is shown. Other uses of our solution are also discussed.

  7. Acoustic signal processing toolbox for array processing

    NASA Astrophysics Data System (ADS)

    Pham, Tien; Whipps, Gene T.

    2003-08-01

    The US Army Research Laboratory (ARL) has developed an acoustic signal processing toolbox (ASPT) for acoustic sensor array processing. The intent of this document is to describe the toolbox and its uses. The ASPT is a GUI-based software that is developed and runs under MATLAB. The current version, ASPT 3.0, requires MATLAB 6.0 and above. ASPT contains a variety of narrowband (NB) and incoherent and coherent wideband (WB) direction-of-arrival (DOA) estimation and beamforming algorithms that have been researched and developed at ARL. Currently, ASPT contains 16 DOA and beamforming algorithms. It contains several different NB and WB versions of the MVDR, MUSIC and ESPRIT algorithms. In addition, there are a variety of pre-processing, simulation and analysis tools available in the toolbox. The user can perform simulation or real data analysis for all algorithms with user-defined signal model parameters and array geometries.

  8. Multi-sensor magnetoencephalography with atomic magnetometers

    PubMed Central

    Johnson, Cort N; Schwindt, P D D; Weisend, M

    2014-01-01

    The authors have detected magnetic fields from the human brain with two independent, simultaneously operating rubidium spin-exchange-relaxation-free magnetometers. Evoked responses from auditory stimulation were recorded from multiple subjects with two multi-channel magnetometers located on opposite sides of the head. Signal processing techniques enabled by multi-channel measurements were used to improve signal quality. This is the first demonstration of multi-sensor atomic magnetometer magnetoencephalography and provides a framework for developing a non-cryogenic, whole-head magnetoencephalography array for source localization. PMID:23939051

  9. Towards operational multisensor registration

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J. M.; Kwok, Ronald; Curlander, John C.

    1991-01-01

    To use data from a number of different remote sensors in a synergistic manner, a multidimensional analysis of the data is necessary. However, prior to this analysis, processing to correct for the systematic geometric distortion characteristic of each sensor is required. Furthermore, the registration process must be fully automated to handle a large volume of data and high data rates. A conceptual approach towards an operational multisensor registration algorithm is presented. The performance requirements of the algorithm are first formulated given the spatially, temporally, and spectrally varying factors that influence the image characteristics and the science requirements of various applications. Several registration techniques that fit within the structure of this algorithm are also presented. Their performance was evaluated using a multisensor test data set assembled from LANDSAT TM, SEASAT, SIR-B, Thermal Infrared Multispectral Scanner (TIMS), and SPOT sensors.

  10. Airborne multisensor pod system (AMPS) data: Multispectral data integration and processing hints

    SciTech Connect

    Leary, T.J.; Lamb, A.

    1996-11-01

    The Department of Energy`s Office of Arms Control and Non-Proliferation (NN-20) has developed a suite of airborne remote sensing systems that simultaneously collect coincident data from a US Navy P-3 aircraft. The primary objective of the Airborne Multisensor Pod System (AMPS) Program is {open_quotes}to collect multisensor data that can be used for data research, both to reduce interpretation problems associated with data overload and to develop information products more complete than can be obtained from any single sensor.{close_quotes} The sensors are housed in wing-mounted pods and include: a Ku-Band Synthetic Aperture Radar; a CASI Hyperspectral Imager; a Daedalus 3600 Airborne Multispectral Scanner; a Wild Heerbrugg RC-30 motion compensated large format camera; various high resolution, light intensified and thermal video cameras; and several experimental sensors (e.g. the Portable Hyperspectral Imager of Low-Light Spectroscopy (PHILLS)). Over the past year or so, the Coastal Marine Resource Assessment (CAMRA) group at the Florida Department of Environmental Protection`s Marine Research Institute (FMRI) has been working with the Department of Energy through the Naval Research Laboratory to develop applications and products from existing data. Considerable effort has been spent identifying image formats integration parameters. 2 refs., 3 figs., 2 tabs.

  11. Acoustic Vector-Sensor Array Processing

    DTIC Science & Technology

    2010-06-01

    133 6.2 Future Work in VSA Processing . . . . . . . . . . . . . . . . . . . . . 135 A Supplemental Material 137 A.1 Symmetric Noise Distributions...nulls and widening the array response. The spatial spreading in Figure 2.4.1 is exag- gerated to illustrate its effects on the array response...resolution. 6.2 Future Work in VSA Processing The last chapter of this thesis is not the final chapter in vector-sensor array research. The doors opened

  12. Development of a solid-state multi-sensor array camera for real time imaging of magnetic fields

    NASA Astrophysics Data System (ADS)

    Benitez, D.; Gaydecki, P.; Quek, S.; Torres, V.

    2007-07-01

    The development of a real-time magnetic field imaging camera based on solid-state sensors is described. The final laboratory comprises a 2D array of 33 x 33 solid state, tri-axial magneto-inductive sensors, and is located within a large current-carrying coil. This may be excited to produce either a steady or time-varying magnetic field. Outputs from several rows of sensors are routed to a sub-master controller and all sub-masters route to a master-controller responsible for data coordination and signal pre-processing. The data are finally streamed to a host computer via a USB interface and the image generated and displayed at a rate of several frames per second. Accurate image generation is predicated on a knowledge of the sensor response, magnetic field perturbations and the nature of the target respecting permeability and conductivity. To this end, the development of the instrumentation has been complemented by extensive numerical modelling of field distribution patterns using boundary element methods. Although it was originally intended for deployment in the nondestructive evaluation (NDE) of reinforced concrete, it was soon realised during the course of the work that the magnetic field imaging system had many potential applications, for example, in medicine, security screening, quality assurance (such as the food industry), other areas of nondestructive evaluation (NDE), designs associated with magnetic fields, teaching and research.

  13. Integrating Scientific Array Processing into Standard SQL

    NASA Astrophysics Data System (ADS)

    Misev, Dimitar; Bachhuber, Johannes; Baumann, Peter

    2014-05-01

    We live in a time that is dominated by data. Data storage is cheap and more applications than ever accrue vast amounts of data. Storing the emerging multidimensional data sets efficiently, however, and allowing them to be queried by their inherent structure, is a challenge many databases have to face today. Despite the fact that multidimensional array data is almost always linked to additional, non-array information, array databases have mostly developed separately from relational systems, resulting in a disparity between the two database categories. The current SQL standard and SQL DBMS supports arrays - and in an extension also multidimensional arrays - but does so in a very rudimentary and inefficient way. This poster demonstrates the practicality of an SQL extension for array processing, implemented in a proof-of-concept multi-faceted system that manages a federation of array and relational database systems, providing transparent, efficient and scalable access to the heterogeneous data in them.

  14. Array algebra estimation in signal processing

    NASA Astrophysics Data System (ADS)

    Rauhala, U. A.

    A general theory of linear estimators called array algebra estimation is interpreted in some terms of multidimensional digital signal processing, mathematical statistics, and numerical analysis. The theory has emerged during the past decade from the new field of a unified vector, matrix and tensor algebra called array algebra. The broad concepts of array algebra and its estimation theory cover several modern computerized sciences and technologies converting their established notations and terminology into one common language. Some concepts of digital signal processing are adopted into this language after a review of the principles of array algebra estimation and its predecessors in mathematical surveying sciences.

  15. The Applicability of Incoherent Array Processing to IMS Seismic Arrays

    NASA Astrophysics Data System (ADS)

    Gibbons, Steven J.

    2014-03-01

    The seismic arrays of the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are highly diverse in size and configuration, with apertures ranging from under 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high-frequency phases lacking coherence between sensors. Pipeline detection algorithms often miss such phases, since they only consider frequencies low enough to allow coherent array processing, and phases that are detected are often attributed qualitatively incorrect backazimuth and slowness estimates. This can result in missed events, due to either a lack of contributing phases or by corruption of event hypotheses by spurious detections. It has been demonstrated previously that continuous spectral estimation can both detect and estimate phases on the largest aperture arrays, with arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity, as is the case for classical f-k analysis, and the ability to estimate slowness vectors requires sufficiently large inter-sensor distances to resolve time-delays between pulses with a period of the order 4-5 s. Spectrogram beampacking works well on five IMS arrays with apertures over 20 km (NOA, AKASG, YKA, WRA, and KURK) without additional post-processing. Seven arrays with 10-20 km aperture (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 s period signal. Even for medium aperture arrays which can provide high-quality coherent slowness estimates, a complementary spectrogram beampacking procedure could act as a quality control by providing non-aliased estimates when the coherent slowness grids display

  16. Optical signal processing of phased array radar

    NASA Astrophysics Data System (ADS)

    Weverka, Robert T.

    This thesis develops optical processors that scale to very high processing speed. Optical signal processing is often promoted on the basis of smaller size, lower weight and lower power consumption as well as higher signal processing speed. While each of these requirements has applications, it is the ones that require processing speed beyond that available in electronics that are most compelling. Thirty years ago, optical processing was the only method fast enough to process Synthetic Aperture Radar (SAR), one of the more demanding signal processing tasks at this time. Since that time electronic processing speed has improved sufficiently to tackle that problem. We have sought out the problems that require significantly higher processing speed and developed optical processors that tackle these more difficult problems. The components that contribute to high signal processing speed are high input signal bandwidth, a large number of parallel input channels each with this high bandwidth, and a large number of parallel operations required on each input channel. Adaptive signal processing for phased array radar has all of these factors. The processors developed for this task scale well in three dimensions, which allows them to maximize parallelism for high speed. This thesis explores an example of a negative feedback adaptive phased array processor and an example of a positive feedback phased array processor. The negative feedback processor uses and array of inputs in up to two dimensions together with the time history of the signal in the third dimension to adapt the array pattern to null out incoming jammer signals. The positive feedback processor uses the incoming signals and assumptions about the radar scene to correct for position errors in a phased array. Discovery and analysis of these new processors are facilitated by an original volume holographic analysis technique developed in the thesis. The thesis includes a new acoustooptic Bragg cell geometry developed with

  17. Solid-State Multi-Sensor Array System for Real Time Imaging of Magnetic Fields and Ferrous Objects

    NASA Astrophysics Data System (ADS)

    Benitez, D.; Gaydecki, P.; Quek, S.; Torres, V.

    2008-02-01

    In this paper the development of a solid-state sensors based system for real-time imaging of magnetic fields and ferrous objects is described. The system comprises 1089 magneto inductive solid state sensors arranged in a 2D array matrix of 33×33 files and columns, equally spaced in order to cover an approximate area of 300 by 300 mm. The sensor array is located within a large current-carrying coil. Data is sampled from the sensors by several DSP controlling units and finally streamed to a host computer via a USB 2.0 interface and the image generated and displayed at a rate of 20 frames per minute. The development of the instrumentation has been complemented by extensive numerical modeling of field distribution patterns using boundary element methods. The system was originally intended for deployment in the non-destructive evaluation (NDE) of reinforced concrete. Nevertheless, the system is not only capable of producing real-time, live video images of the metal target embedded within any opaque medium, it also allows the real-time visualization and determination of the magnetic field distribution emitted by either permanent magnets or geometries carrying current. Although this system was initially developed for the NDE arena, it could also have many potential applications in many other fields, including medicine, security, manufacturing, quality assurance and design involving magnetic fields.

  18. Process for forming transparent aerogel insulating arrays

    DOEpatents

    Tewari, P.H.; Hunt, A.J.

    1985-09-04

    An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO/sub 2/, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO/sub 2/, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40/sup 0/C instead of at about 270/sup 0/C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementary particles or cosmic rays.

  19. Process for forming transparent aerogel insulating arrays

    DOEpatents

    Tewari, Param H.; Hunt, Arlon J.

    1986-01-01

    An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO.sub.2, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO.sub.2, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40.degree. C. instead of at about 270.degree. C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementry particles or cosmic rays.

  20. Barrow real-time sea ice mass balance data: ingestion, processing, dissemination and archival of multi-sensor data

    NASA Astrophysics Data System (ADS)

    Grimes, J.; Mahoney, A. R.; Heinrichs, T. A.; Eicken, H.

    2012-12-01

    Sensor data can be highly variable in nature and also varied depending on the physical quantity being observed, sensor hardware and sampling parameters. The sea ice mass balance site (MBS) operated in Barrow by the University of Alaska Fairbanks (http://seaice.alaska.edu/gi/observatories/barrow_sealevel) is a multisensor platform consisting of a thermistor string, air and water temperature sensors, acoustic altimeters above and below the ice and a humidity sensor. Each sensor has a unique specification and configuration. The data from multiple sensors are combined to generate sea ice data products. For example, ice thickness is calculated from the positions of the upper and lower ice surfaces, which are determined using data from downward-looking and upward-looking acoustic altimeters above and below the ice, respectively. As a data clearinghouse, the Geographic Information Network of Alaska (GINA) processes real time data from many sources, including the Barrow MBS. Doing so requires a system that is easy to use, yet also offers the flexibility to handle data from multisensor observing platforms. In the case of the Barrow MBS, the metadata system needs to accommodate the addition of new and retirement of old sensors from year to year as well as instrument configuration changes caused by, for example, spring melt or inquisitive polar bears. We also require ease of use for both administrators and end users. Here we present the data and processing steps of using sensor data system powered by the NoSQL storage engine, MongoDB. The system has been developed to ingest, process, disseminate and archive data from the Barrow MBS. Storing sensor data in a generalized format, from many different sources, is a challenging task, especially for traditional SQL databases with a set schema. MongoDB is a NoSQL (not only SQL) database that does not require a fixed schema. There are several advantages using this model over the traditional relational database management system (RDBMS

  1. Semiotic foundation for multisensor-multilook fusion

    NASA Astrophysics Data System (ADS)

    Myler, Harley R.

    1998-07-01

    This paper explores the concept of an application of semiotic principles to the design of a multisensor-multilook fusion system. Semiotics is an approach to analysis that attempts to process media in a united way using qualitative methods as opposed to quantitative. The term semiotic refers to signs, or signatory data that encapsulates information. Semiotic analysis involves the extraction of signs from information sources and the subsequent processing of the signs into meaningful interpretations of the information content of the source. The multisensor fusion problem predicated on a semiotic system structure and incorporating semiotic analysis techniques is explored and the design for a multisensor system as an information fusion system is explored. Semiotic analysis opens the possibility of using non-traditional sensor sources and modalities in the fusion process, such as verbal and textual intelligence derived from human observers. Examples of how multisensor/multimodality data might be analyzed semiotically is shown and discussion on how a semiotic system for multisensor fusion could be realized is outlined. The architecture of a semiotic multisensor fusion processor that can accept situational awareness data is described, although an implementation has not as yet been constructed.

  2. Photorefractive processing for large adaptive phased arrays

    NASA Astrophysics Data System (ADS)

    Weverka, Robert T.; Wagner, Kelvin; Sarto, Anthony

    1996-03-01

    An adaptive null-steering phased-array optical processor that utilizes a photorefractive crystal to time integrate the adaptive weights and null out correlated jammers is described. This is a beam-steering processor in which the temporal waveform of the desired signal is known but the look direction is not. The processor computes the angle(s) of arrival of the desired signal and steers the array to look in that direction while rotating the nulls of the antenna pattern toward any narrow-band jammers that may be present. We have experimentally demonstrated a simplified version of this adaptive phased-array-radar processor that nulls out the narrow-band jammers by using feedback-correlation detection. In this processor it is assumed that we know a priori only that the signal is broadband and the jammers are narrow band. These are examples of a class of optical processors that use the angular selectivity of volume holograms to form the nulls and look directions in an adaptive phased-array-radar pattern and thereby to harness the computational abilities of three-dimensional parallelism in the volume of photorefractive crystals. The development of this processing in volume holographic system has led to a new algorithm for phased-array-radar processing that uses fewer tapped-delay lines than does the classic time-domain beam former. The optical implementation of the new algorithm has the further advantage of utilization of a single photorefractive crystal to implement as many as a million adaptive weights, allowing the radar system to scale to large size with no increase in processing hardware.

  3. Multichannel/Multisensor Signal Processing In Uncertain Environments With Application To Multitarget Tracking.

    DTIC Science & Technology

    1998-05-22

    impulse response estimation for MIMO channels using a Godard cost function," IEEE Trans. Signal Processing, vol. SP-45, pp. 268- 271, Jan. 1997. [3...using a Godard cost function," IEEE Trans. Signal Processing, vol. SP-45, pp. 268- 271, Jan. 1997. 24 [3] Special Issue, IEEE Transactions on Signal...excluding z = 0), then finite length inverse filters suffice. For an analysis and further elaborations, see [22] and [16] where a Godard cost function is

  4. Processing Requirements For Multi-Sensor, Low-Cost Brilliant Munitions

    NASA Astrophysics Data System (ADS)

    Klein, Lawrence A.; Kassis, Suhail Y.

    1989-09-01

    A generic mission for an autonomous fire-and-forget brilliant munition is presented and used to identify the functions that an embedded signal processor must perform. Based on these functions and other operational factors (such as weather, larger search areas, lower false alarm rates, and munition maneuverability), the processing loads in bits/second, messages/second, operations/second, and instructions/second are derived. The paper concludes with an evaluation of general implementation issues, such as the requirements for data fusion, distributed and parallel processing architectures, trusted software, and low-cost hardware.

  5. Computational process optimization of array edges

    NASA Astrophysics Data System (ADS)

    Küchler, Bernd; Shamsuarov, Artem; Mülders, Thomas; Klostermann, Ulrich; Yang, Seung-Hune; Moon, Seongho; Domnenko, Vitaliy; Park, Sung-Woon

    2012-03-01

    DRAM chip space is mainly determined by the size of the memory cell array patterns which consist of periodic memory cell features. Resolution Enhancement Techniques are used to optimize the periodic pattern process performance. This is often realized with aggressively coherent illumination sources supporting the periodic pattern pitch only and making an array edge correction very difficult. The edge can be the most critical pattern since it forms the transition from periodic patterns to non periodic periphery, so it combines the most critical pitch and highest susceptibility to defocus. Non functional dummy structures are very effective to support the outermost edge but are very expensive, so their reduction or avoidance directly increases chip space efficiency. This paper focuses on how to optimize the DRAM array edge automatically in contrast to manual optimization approaches that were used effectively but at high cost. We will show how to squeeze out the masks degrees of freedom to stay within tight pattern tolerances. In that way we minimize process variations and the need of costly non-functional dummy structures. To obtain the best possible results the optimization has to account for complex boundary conditions: correct resist effect prediction, mask manufacturability constraints, low dose, low MEEF, conservation of symmetries and SRAF printing, simultaneous optimization of main features and SRAFs. By incorporating these complex boundary conditions during optimization we aim to provide first time right layouts without the need for any post processing.

  6. Processing and Exploitation of Multisensor Optical Data for Coastal Water Applications- The HIGHROC Project

    NASA Astrophysics Data System (ADS)

    Ruddick, Kevin; Brockmann, Carsten; Creach, Veronique; De Keukelaere, Liesbeth; Doxaran, David; Forster, Rodney; Jaccard, Pierre; Knaeps, Els; Leberton, Carole; Ledang, Anna Birgitta; Nechad, Bouchra; Norli, Marit; Nova, Stefani; Ody, Anouck; Pringle, Nicholas; Sorensen, Kai; Stelzer, Kerstin; Van der Zande, Dimitry; Vanhellemont, Quinten

    2016-08-01

    The FP7/HIGHROC ("HIGH spatial and temporal Resolution Ocean Colour") Project is developing the next generation of optical products for coastal water services. These products are based on both mainstream ocean colour sensors (Sentinel-3/OLCI, VIIRS) and other satellite missions such as the meteorological MSG/SEVIRI sensors and the land-oriented Landsat-8 (L8) and Sentinel-2 (S2) missions. The geostationary SEVIRI gives data every 15 minutes, offering much better temporal coverage in partially cloudy periods and the possibility to follow diurnal and tidal processes in cloud-free periods. S2 and L8 offer much better spatial resolution, down to 10m (S2), allowing detection of many human impacts invisible at 300m resolution. HIGHROC R&D includes the development of algorithms, acquisition of in situ measurements and programming of image processing chains. The new products and services will be tested during User Service Trials covering a range of applications including coastal water quality monitoring, Environmental Impact Assessment and sediment transport.

  7. Multisensor Image Analysis System

    DTIC Science & Technology

    1993-04-15

    AD-A263 679 II Uli! 91 Multisensor Image Analysis System Final Report Authors. Dr. G. M. Flachs Dr. Michael Giles Dr. Jay Jordan Dr. Eric...or decision, unless so designated by other documentation. 93-09739 *>ft s n~. now illlllM3lMVf Multisensor Image Analysis System Final...Multisensor Image Analysis System 3. REPORT TYPE AND DATES COVERED FINAL: LQj&tt-Z JZOfVL 5. FUNDING NUMBERS 93 > 6. AUTHOR(S) Drs. Gerald

  8. Digital processing of array seismic recordings

    USGS Publications Warehouse

    Ryall, Alan; Birtill, John

    1962-01-01

    This technical letter contains a brief review of the operations which are involved in digital processing of array seismic recordings by the methods of velocity filtering, summation, cross-multiplication and integration, and by combinations of these operations (the "UK Method" and multiple correlation). Examples are presented of analyses by the several techniques on array recordings which were obtained by the U.S. Geological Survey during chemical and nuclear explosions in the western United States. Seismograms are synthesized using actual noise and Pn-signal recordings, such that the signal-to-noise ratio, onset time and velocity of the signal are predetermined for the synthetic record. These records are then analyzed by summation, cross-multiplication, multiple correlation and the UK technique, and the results are compared. For all of the examples presented, analysis by the non-linear techniques of multiple correlation and cross-multiplication of the traces on an array recording are preferred to analyses by the linear operations involved in summation and the UK Method.

  9. Gallium arsenide processing for gate array logic

    NASA Astrophysics Data System (ADS)

    Cole, Eric D.

    1989-09-01

    The development of a reliable and reproducible GaAs process was initiated for applications in gate array logic. Gallium Arsenide is an extremely important material for high speed electronic applications in both digital and analog circuits since its electron mobility is 3 to 5 times that of silicon, this allows for faster switching times for devices fabricated with it. Unfortunately GaAs is an extremely difficult material to process with respect to silicon and since it includes the arsenic component GaAs can be quite dangerous (toxic) especially during some heating steps. The first stage of the research was directed at developing a simple process to produce GaAs MESFETs. The MESFET (MEtal Semiconductor Field Effect Transistor) is the most useful, practical and simple active device which can be fabricated in GaAs. It utilizes an ohmic source and drain contact separated by a Schottky gate. The gate width is typically a few microns. Several process steps were required to produce a good working device including ion implantation, photolithography, thermal annealing, and metal deposition. A process was designed to reduce the total number of steps to a minimum so as to reduce possible errors. The first run produced no good devices. The problem occurred during an aluminum etch step while defining the gate contacts. It was found that the chemical etchant attacked the GaAs causing trenching and subsequent severing of the active gate region from the rest of the device. Thus all devices appeared as open circuits. This problem is being corrected and since it was the last step in the process correction should be successful. The second planned stage involves the circuit assembly of the discrete MESFETs into logic gates for test and analysis. Finally the third stage is to incorporate the designed process with the tested circuit in a layout that would produce the gate array as a GaAs integrated circuit.

  10. Gallium arsenide processing for gate array logic

    NASA Technical Reports Server (NTRS)

    Cole, Eric D.

    1989-01-01

    The development of a reliable and reproducible GaAs process was initiated for applications in gate array logic. Gallium Arsenide is an extremely important material for high speed electronic applications in both digital and analog circuits since its electron mobility is 3 to 5 times that of silicon, this allows for faster switching times for devices fabricated with it. Unfortunately GaAs is an extremely difficult material to process with respect to silicon and since it includes the arsenic component GaAs can be quite dangerous (toxic) especially during some heating steps. The first stage of the research was directed at developing a simple process to produce GaAs MESFETs. The MESFET (MEtal Semiconductor Field Effect Transistor) is the most useful, practical and simple active device which can be fabricated in GaAs. It utilizes an ohmic source and drain contact separated by a Schottky gate. The gate width is typically a few microns. Several process steps were required to produce a good working device including ion implantation, photolithography, thermal annealing, and metal deposition. A process was designed to reduce the total number of steps to a minimum so as to reduce possible errors. The first run produced no good devices. The problem occurred during an aluminum etch step while defining the gate contacts. It was found that the chemical etchant attacked the GaAs causing trenching and subsequent severing of the active gate region from the rest of the device. Thus all devices appeared as open circuits. This problem is being corrected and since it was the last step in the process correction should be successful. The second planned stage involves the circuit assembly of the discrete MESFETs into logic gates for test and analysis. Finally the third stage is to incorporate the designed process with the tested circuit in a layout that would produce the gate array as a GaAs integrated circuit.

  11. Gallium arsenide processing for gate array logic

    NASA Technical Reports Server (NTRS)

    Cole, Eric D.

    1989-01-01

    The development of a reliable and reproducible GaAs process was initiated for applications in gate array logic. Gallium Arsenide is an extremely important material for high speed electronic applications in both digital and analog circuits since its electron mobility is 3 to 5 times that of silicon, this allows for faster switching times for devices fabricated with it. Unfortunately GaAs is an extremely difficult material to process with respect to silicon and since it includes the arsenic component GaAs can be quite dangerous (toxic) especially during some heating steps. The first stage of the research was directed at developing a simple process to produce GaAs MESFETs. The MESFET (MEtal Semiconductor Field Effect Transistor) is the most useful, practical and simple active device which can be fabricated in GaAs. It utilizes an ohmic source and drain contact separated by a Schottky gate. The gate width is typically a few microns. Several process steps were required to produce a good working device including ion implantation, photolithography, thermal annealing, and metal deposition. A process was designed to reduce the total number of steps to a minimum so as to reduce possible errors. The first run produced no good devices. The problem occurred during an aluminum etch step while defining the gate contacts. It was found that the chemical etchant attacked the GaAs causing trenching and subsequent severing of the active gate region from the rest of the device. Thus all devices appeared as open circuits. This problem is being corrected and since it was the last step in the process correction should be successful. The second planned stage involves the circuit assembly of the discrete MESFETs into logic gates for test and analysis. Finally the third stage is to incorporate the designed process with the tested circuit in a layout that would produce the gate array as a GaAs integrated circuit.

  12. Design, processing, and testing of LSI arrays for space station

    NASA Technical Reports Server (NTRS)

    Ipri, A. C.

    1976-01-01

    The applicability of a particular process for the fabrication of large scale integrated circuits is described. Test arrays were designed, built, and tested, and then utilized. A set of optimum dimensions for LSI arrays was generated. The arrays were applied to yield improvement through process innovation, and additional applications were suggested in the areas of yield prediction, yield modeling, and process reliability.

  13. An algorithm for signal processing in multibeam antenna arrays

    NASA Astrophysics Data System (ADS)

    Danilevskii, L. N.; Domanov, Iu. A.; Korobko, O. V.

    1980-09-01

    A signal processing method for multibeam antenna arrays is presented which can be used to effectively reduce discrete-phasing sidelobes. Calculations of an 11-element array are presented as an example.

  14. Array signal processing in the NASA Deep Space Network

    NASA Technical Reports Server (NTRS)

    Pham, Timothy T.; Jongeling, Andre P.

    2004-01-01

    In this paper, we will describe the benefits of arraying and past as well as expected future use of this application. The signal processing aspects of array system are described. Field measurements via actual tracking spacecraft are also presented.

  15. Array signal processing in the NASA Deep Space Network

    NASA Technical Reports Server (NTRS)

    Pham, Timothy T.; Jongeling, Andre P.

    2004-01-01

    In this paper, we will describe the benefits of arraying and past as well as expected future use of this application. The signal processing aspects of array system are described. Field measurements via actual tracking spacecraft are also presented.

  16. Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM) System

    PubMed Central

    Wan, Bo; Fu, Guicui; Li, Yanruoyue; Zhao, Youhu

    2016-01-01

    The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM) theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC) tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects. PMID:27517935

  17. Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM) System.

    PubMed

    Wan, Bo; Fu, Guicui; Li, Yanruoyue; Zhao, Youhu

    2016-08-10

    The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM) theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC) tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects.

  18. Hierarchical Robot Control In A Multisensor Environment

    NASA Astrophysics Data System (ADS)

    Bhanu, Bir; Thune, Nils; Lee, Jih Kun; Thune, Mari

    1987-03-01

    Automatic recognition, inspection, manipulation and assembly of objects will be a common denominator in most of tomorrow's highly automated factories. These tasks will be handled by intelligent computer controlled robots with multisensor capabilities which contribute to desired flexibility and adaptability. The control of a robot in such a multisensor environment becomes of crucial importance as the complexity of the problem grows exponentially with the number of sensors, tasks, commands and objects. In this paper we present an approach which uses CAD (Computer-Aided Design) based geometric and functional models of objects together with action oriented neuroschemas to recognize and manipulate objects by a robot in a multisensor environment. The hierarchical robot control system is being implemented on a BBN Butterfly multi processor. Index terms: CAD, Hierarchical Control, Hypothesis Generation and Verification, Parallel Processing, Schemas

  19. Multipath Array Processing for Co-Prime and Under-Sampled Sensor Arrays

    DTIC Science & Technology

    2015-09-30

    freedom than physical sensors present in the array. However, the cost of the achievable degrees of freedom is a loss of approximately half of the array...of degrees of freedom of the array. A co-prime frequency comb is a novel active sonar waveform that achieves range-Doppler performance similar...localization with moving co-prime arrays,” in Acoustics, Speech and Signal Processing (ICASSP), 2015 IEEE International Conference on, 2015. 6 2

  20. Square Kilometre Array Science Data Processing

    NASA Astrophysics Data System (ADS)

    Nikolic, Bojan; SDP Consortium, SKA

    2014-04-01

    The Square Kilometre Array (SKA) is planned to be, by a large factor, the largest and most sensitive radio telescope ever constructed. The first phase of the telescope (SKA1), now in the design phase, will in itself represent a major leap in capabilities compared to current facilities. These advances are to a large extent being made possible by advances in available computer processing power so that that larger numbers of smaller, simpler and cheaper receptors can be used. As a result of greater reliance and demands on computing, ICT is becoming an ever more integral part of the telescope. The Science Data Processor is the part of the SKA system responsible for imaging, calibration, pulsar timing, confirmation of pulsar candidates, derivation of some further derived data products, archiving and providing the data to the users. It will accept visibilities at data rates at several TB/s and require processing power for imaging in range 100 petaFLOPS -- ~1 ExaFLOPS, putting SKA1 into the regime of exascale radio astronomy. In my talk I will present the overall SKA system requirements and how they drive these high data throughput and processing requirements. Some of the key challenges for the design of SDP are: - Identifying sufficient parallelism to utilise very large numbers of separate compute cores that will be required to provide exascale computing throughput - Managing efficiently the high internal data flow rates - A conceptual architecture and software engineering approach that will allow adaptation of the algorithms as we learn about the telescope and the atmosphere during the commissioning and operational phases - System management that will deal gracefully with (inevitably frequent) failures of individual units of the processing system In my talk I will present possible initial architectures for the SDP system that attempt to address these and other challenges.

  1. The influence of the arrangements of multi-sensor probe arrays on the accuracy of simultaneously measured velocity and velocity gradient-based statistics in turbulent shear flows

    NASA Astrophysics Data System (ADS)

    Vukoslavčević, P. V.; Wallace, J. M.

    2013-06-01

    A highly resolved turbulent channel flow direct numerical simulation (DNS) with Re τ = 200 has been used to investigate the influence of the arrangements of the arrays (array configurations), within the sensing area of a multi-array hot-wire probe on the measurement accuracy of velocity and velocity gradient-based statistics. To eliminate all effects related to the sensor response and array characteristics (such as sensor dimensions, overheat ratio, thermal cross talk, number and orientations of the sensors and uniqueness range) so that this study could be focused solely on the effects of the array configurations (positions and separations), a concept of a perfect array was introduced, that is, one that can exactly and simultaneously measure all three velocity components at its center. The velocity component values, measured by these perfect arrays, are simply the DNS values computed at these points. Using these velocity components, the velocity and velocity gradient-based statistics were calculated assuming a linear velocity variation over the probes' sensing areas. The calculated values are compared to the DNS values for various array arrangements to study the influence of these arrangements on the measurement accuracy. Typical array configurations that previously have been used for physical probes were tested. It is demonstrated that the array arrangements strongly influence the accuracy of some of the velocity and velocity gradient-based statistics and that no single configuration exists, for a given spatial resolution, which gives the best accuracy for all of the statistics characterizing a turbulent shear flow.

  2. Synergetic Multisensor Fusion

    DTIC Science & Technology

    1990-11-30

    technology have led to increased interest in using DEMs for navigation and other applications. In particular, DEMs are attractive for use in aircraft...Multisensor Fusion for Computer Vision [67]. 30 6. POSI!IONAL zSTIM&TION TECEnIQUzs FOR AN OUTDOOR MOBLE ROBOT The autonomous navigation of mobile robots is

  3. Digital image processing software system using an array processor

    SciTech Connect

    Sherwood, R.J.; Portnoff, M.R.; Journeay, C.H.; Twogood, R.E.

    1981-03-10

    A versatile array processor-based system for general-purpose image processing was developed. At the heart of this system is an extensive, flexible software package that incorporates the array processor for effective interactive image processing. The software system is described in detail, and its application to a diverse set of applications at LLNL is briefly discussed. 4 figures, 1 table.

  4. Acetylcholine molecular arrays enable quantum information processing

    NASA Astrophysics Data System (ADS)

    Tamulis, Arvydas; Majauskaite, Kristina; Talaikis, Martynas; Zborowski, Krzysztof; Kairys, Visvaldas

    2017-09-01

    We have found self-assembly of four neurotransmitter acetylcholine (ACh) molecular complexes in a water molecules environment by using geometry optimization with DFT B97d method. These complexes organizes to regular arrays of ACh molecules possessing electronic spins, i.e. quantum information bits. These spin arrays could potentially be controlled by the application of a non-uniform external magnetic field. The proper sequence of resonant electromagnetic pulses would then drive all the spin groups into the 3-spin entangled state and proceed large scale quantum information bits.

  5. Multi-Sensor Detection of Obscured and Buried Objects

    DTIC Science & Technology

    2014-12-22

    15. SUBJECT TERMS Landmine detection, University of Florida, pattern recognition, image processing, multi-sensor fusion, classifier development...Nearest Neighbor Classifier , Year 2 • Gradient Angle Model Algorithm on Wideband EMI data Classifier , • Context Dependent Multi-Sensor Fusion...Notation="TeX" >$K$</tex></formula>-Nearest Neighbor Classifier , IEEE Transactions on Fuzzy Systems, (02 2009): 0. doi: 10.1109/TFUZZ

  6. Multisensor data fusion and visualization for impact echo testing of bridge decks

    NASA Astrophysics Data System (ADS)

    Wei, Xiangmin; Xie, Zhenhua; Zhang, Ying

    2012-04-01

    An effective multisensor data fusion and visualization framework is proposed for accurate localization and effective visualization of delamination in concrete bridge decks based on impact echo (IE) nondestructive evaluation method. The fusion rules are developed by analyzing the spatial distribution of surface motion resulting from mechanical impacts applied at different locations based on numerical simulation. The proposed approach can process, integrate and interpret the data from a series IE source-receiver arrays to improve the accuracy and reliability of delamination characterization for bridge decks. The visualization approach provides an intuitive way for users to visualize the internal defects of concrete bridge decks.

  7. Concept of multisensor industrial thermal imaging system

    NASA Astrophysics Data System (ADS)

    Pancik, Juraj; Scepko, Pavel; Sekerka, Vladimir; Hoffmann, Uwe; Reichardt, Thomas

    1999-09-01

    This paper describes the development and system integration of a non-cooled industrial thermal imaging system (ITIS) based on an uncooled linear array 1 X 128 pyroelectric detectors and internal scanner and the concept of multisensor industrial thermal imaging system for inspection/monitoring thermal processes or hazardous environments. In previous time, as first step, was developed a thermal imaging system in which was a two dimensional capability is reached with mounting of the camera on the precise programmable positional unit that exhibits positioning capability in 2 D.o.F. (degree of freedom). As a second stage of a developing an industrial thermal imaging system was mechanical design and construction of an internal scanner for linear array. Internal scanner has ability to create two-dimensional frame with selectable numbers of rows (from 1 to 128). Frame rate is depending on a numbers of rows in a frame (from 128 Hz to 1 Hz) and software averaging. The measured NETD of a thermal imaging system, without frame averaging, is better than 0.5 degrees Celsius (for lens with F equals 0.7 at 300 K). The digital part of a camera is equipped with 32 bit floating point digital signal processor (SHARC, Analog Devices), fieldbus controller (COM20020, SMCS, with implemented low-level protocol ARCNET ANSI ATA 878.1 with data rate 5 Mbit per second) and fieldbus interfaces (for twisted pair and coaxial cable). The positional unit was also attached with fieldbus controller. This paper also deals with a conceptual design of a multi- sensor and multi-actuator system based on a ARCNET Local Area Networks (LAN) with set of nodes like thermal or visible cameras, positional units and other necessary nodes.

  8. Reduced Complexity High Performance Array Processing

    DTIC Science & Technology

    1998-01-01

    constrained beamforming,” IEEE Transactions on Aerospace and Electronic Systems, January 1982. [5] J . Scott Goldstein and Irving S. Reed, “Theory of...partially adaptive radar,” IEEE Transactions on Aerospace and Electronic Systems, October 1997. [6] J . Scott Goldstein, Irving S. Reed, and John A...Computers. [7] Barry D. Van Veen, “Eigenstructure-based partially adaptive array design,” IEEE Transactions on Antennas and Propagation, March 1988. [8] J

  9. PMMA microlens array fabricated by indentation process

    NASA Astrophysics Data System (ADS)

    Cirino, Giuseppe A.; Jasinevicius, Renato G.

    2017-02-01

    This work reports the fabrication of a PMMA-based spherical microlens array (MLA), targeting application of Shack-Hartmann wavefront sensor for lens characterization. The array present 10 by 10 elements, with f-number f/# = f/10 (1 mm diameter, 10 mm focal length). The fabrication method employs a computer-controlled mechanical indentation for the fabrication of an insert mold, and subsequent replication by injection molding on PMMA. After replication and de-molding, the PMMA surface containing the negative of the phase profile of the lens array was evaluated by optical profilometry technique, in terms of the surface quality as well as the replication fidelity. The RMS surface roughness level of approximately (λ/10) was found, considering operation in the visible range of spectrum. Optical characterization was based on the evaluation of the sharpness, FWHM, and maximum intensity, IMAX, values associated to the profiles of each of the 100 generated light spots, obtained in the back focal plane of the MLA. An average sharpness of FWHMAVG = 13.9 +/- 8% μm, and average maximum intensity of IMAX AVG = 0.72 +/- 7% a.u. was obtained.

  10. Fabrication of Nanohole Array via Nanodot Array Using Simple Self-Assembly Process of Diblock Copolymer

    NASA Astrophysics Data System (ADS)

    Matsuyama, Tsuyoshi; Kawata, Yoshimasa

    2007-06-01

    We present a simple self-assembly process for fabricating a nanohole array via a nanodot array on a glass substrate by dripping ethanol onto the nanodot array. It is found that well-aligned arrays of nanoholes as well as nanodots are formed on the whole surface of the glass. A dot is transformed into a hole, and the alignment of the nanodots strongly reflects that of the nanoholes. We find that the change in the depth of holes agrees well with the change in the surface energy with the ethanol concentration in the aqueous solution. We believe that the interfacial energy between the nanodots and the dripped ethanol causes the transformation from nanodots into nanoholes. The nanohole arrays are directly applicable to molds for nanopatterned media used in high-density near-field optical data storage. The bit data can be stored and read out using probes with small apertures.

  11. Multi-Sensor Inspection Telerobot

    NASA Technical Reports Server (NTRS)

    Balaram, J.; Hayati, S.; Volpe, R.

    1994-01-01

    This paper describes a telerobotic multi-sensor inspection system for space platforms developed at the Jet Propulsion Laboratory. A multi-sensor inspection end-effector incorporates cameras and lighting for visual inspection, as well as temperature and gas leak-detection sensors.

  12. Integrated Seismic Event Detection and Location by Advanced Array Processing

    SciTech Connect

    Kvaerna, T; Gibbons, S J; Ringdal, F; Harris, D B

    2007-02-09

    The principal objective of this two-year study is to develop and test a new advanced, automatic approach to seismic detection/location using array processing. We address a strategy to obtain significantly improved precision in the location of low-magnitude events compared with current fully-automatic approaches, combined with a low false alarm rate. We have developed and evaluated a prototype automatic system which uses as a basis regional array processing with fixed, carefully calibrated, site-specific parameters in conjuction with improved automatic phase onset time estimation. We have in parallel developed tools for Matched Field Processing for optimized detection and source-region identification of seismic signals. This narrow-band procedure aims to mitigate some of the causes of difficulty encountered using the standard array processing system, specifically complicated source-time histories of seismic events and shortcomings in the plane-wave approximation for seismic phase arrivals at regional arrays.

  13. Performance Comparison of Superresolution Array Processing Algorithms. Revised

    DTIC Science & Technology

    2007-11-02

    OF SUPERRESOLUTION ARRAY PROCESSING ALGORITHMS A.J. BARABELL J. CAPON D.F. DeLONG K.D. SENNE Group 44 J.R. JOHNSON Group 96 PROJECT REPORT...adaptive superresolution direction finding and spatial nulling to support sig- nal copy in the presence of strong cochannel interference. The need for such... superresolution array processing have their origin in spectral estimation for time series. Since the sampling of a function in time is analogous to

  14. Multi-Sensor Distributive On-line Processing, Visualization, and Analysis Infrastructure for an Agricultural Information System at the NASA Goddard Earth Sciences DAAC

    NASA Astrophysics Data System (ADS)

    Teng, W.; Berrick, S.; Leptoukh, G.; Liu, Z.; Rui, H.; Pham, L.; Shen, S.; Zhu, T.

    2004-12-01

    The Goddard Space Flight Center Earth Sciences Data and Information Services Center (GES DISC) Distributed Active Archive Center (DAAC) is developing an Agricultural Information System (AIS), evolved from an existing TRMM Online Visualization and Analysis System (TOVAS), which will operationally provide precipitation and other satellite data products and services. AIS outputs will be integrated into existing operational decision support systems for global crop monitoring, such as that of the U.N. World Food Program. The ability to use the raw data stored in the GES DAAC archives is highly dependent on having a detailed understanding of the data's internal structure and physical implementation. To gain this understanding is a time-consuming process and not a productive investment of the user's time. This is an especially difficult challenge when users need to deal with multi-sensor data that usually are of different structures and resolutions. The AIS has taken a major step towards meeting this challenge by incorporating an underlying infrastructure, called the GES-DISC Interactive Online Visualization and Analysis Infrastructure or "Giovanni," that integrates various components to support web interfaces that allow users to perform interactive analysis on-line without downloading any data. Several instances of the Giovanni-based interface have been or are being created to serve users of TRMM precipitation, MODIS aerosol, and SeaWiFS ocean color data, as well as agricultural applications users. Giovanni-based interfaces are simple to use but powerful. The user selects geophysical parameters, area of interest, and time period; and the system generates an output on screen in a matter of seconds. The currently available output options are (1) area plot - averaged or accumulated over any available data period for any rectangular area; (2) time plot - time series averaged over any rectangular area; (3) Hovmoller plots - longitude-time and latitude-time plots; (4) ASCII

  15. Multi-Sensor Distributive On-Line Processing, Visualization, and Analysis Infrastructure for an Agricultural Information System at the NASA Goddard Earth Sciences DAAC

    NASA Technical Reports Server (NTRS)

    Teng, William; Berrick, Steve; Leptuokh, Gregory; Liu, Zhong; Rui, Hualan; Pham, Long; Shen, Suhung; Zhu, Tong

    2004-01-01

    The Goddard Space Flight Center Earth Sciences Data and Information Services Center (GES DISC) Distributed Active Center (DAAC) is developing an Agricultural Information System (AIS), evolved from an existing TRMM On-line Visualization and Analysis System precipitation and other satellite data products and services. AIS outputs will be ,integrated into existing operational decision support system for global crop monitoring, such as that of the U.N. World Food Program. The ability to use the raw data stored in the GES DAAC archives is highly dependent on having a detailed understanding of the data's internal structure and physical implementation. To gain this understanding is a time-consuming process and not a productive investment of the user's time. This is an especially difficult challenge when users need to deal with multi-sensor data that usually are of different structures and resolutions. The AIS has taken a major step towards meeting this challenge by incorporating an underlying infrastructure, called the GES-DISC Interactive Online Visualization and Analysis Infrastructure or "Giovanni," that integrates various components to support web interfaces that ,allow users to perform interactive analysis on-line without downloading any data. Several instances of the Giovanni-based interface have been or are being created to serve users of TRMM precipitation, MODIS aerosol, and SeaWiFS ocean color data, as well as agricultural applications users. Giovanni-based interfaces are simple to use but powerful. The user selects geophysical ,parameters, area of interest, and time period; and the system generates an output ,on screen in a matter of seconds.

  16. Multi-Sensor Distributive On-Line Processing, Visualization, and Analysis Infrastructure for an Agricultural Information System at the NASA Goddard Earth Sciences DAAC

    NASA Technical Reports Server (NTRS)

    Teng, William; Berrick, Steve; Leptuokh, Gregory; Liu, Zhong; Rui, Hualan; Pham, Long; Shen, Suhung; Zhu, Tong

    2004-01-01

    The Goddard Space Flight Center Earth Sciences Data and Information Services Center (GES DISC) Distributed Active Center (DAAC) is developing an Agricultural Information System (AIS), evolved from an existing TRMM On-line Visualization and Analysis System precipitation and other satellite data products and services. AIS outputs will be ,integrated into existing operational decision support system for global crop monitoring, such as that of the U.N. World Food Program. The ability to use the raw data stored in the GES DAAC archives is highly dependent on having a detailed understanding of the data's internal structure and physical implementation. To gain this understanding is a time-consuming process and not a productive investment of the user's time. This is an especially difficult challenge when users need to deal with multi-sensor data that usually are of different structures and resolutions. The AIS has taken a major step towards meeting this challenge by incorporating an underlying infrastructure, called the GES-DISC Interactive Online Visualization and Analysis Infrastructure or "Giovanni," that integrates various components to support web interfaces that ,allow users to perform interactive analysis on-line without downloading any data. Several instances of the Giovanni-based interface have been or are being created to serve users of TRMM precipitation, MODIS aerosol, and SeaWiFS ocean color data, as well as agricultural applications users. Giovanni-based interfaces are simple to use but powerful. The user selects geophysical ,parameters, area of interest, and time period; and the system generates an output ,on screen in a matter of seconds.

  17. Sonar array processing borrows from geophysics

    SciTech Connect

    Chen, K.

    1989-09-01

    The author reports a recent advance in sonar signal processing that has potential military application. It improves signal extraction by modifying a technique devised by a geophysicist. Sonar signal processing is used to track submarine and surface targets, such as aircraft carriers, oil tankers, and, in commercial applications, schools of fish or sunken treasure. Similar signal-processing techniques help radio astronomers track galaxies, physicians see images of the body interior, and geophysicists map the ocean floor or find oil. This hydrid technique, applied in an experimental system, can help resolve strong signals as well as weak ones in the same step.

  18. A smart multisensor approach to assist blind people in specific urban navigation tasks.

    PubMed

    Ando, B

    2008-12-01

    Visually impaired people are often discouraged in using electronic aids due to complexity of operation, large amount of training, nonoptimized degree of information provided to the user, and high cost. In this paper, a new multisensor architecture is discussed, which would help blind people to perform urban mobility tasks. The device is based on a multisensor strategy and adopts smart signal processing.

  19. Digital interactive image analysis by array processing

    NASA Technical Reports Server (NTRS)

    Sabels, B. E.; Jennings, J. D.

    1973-01-01

    An attempt is made to draw a parallel between the existing geophysical data processing service industries and the emerging earth resources data support requirements. The relationship of seismic data analysis to ERTS data analysis is natural because in either case data is digitally recorded in the same format, resulting from remotely sensed energy which has been reflected, attenuated, shifted and degraded on its path from the source to the receiver. In the seismic case the energy is acoustic, ranging in frequencies from 10 to 75 cps, for which the lithosphere appears semi-transparent. In earth survey remote sensing through the atmosphere, visible and infrared frequency bands are being used. Yet the hardware and software required to process the magnetically recorded data from the two realms of inquiry are identical and similar, respectively. The resulting data products are similar.

  20. Removing Background Noise with Phased Array Signal Processing

    NASA Technical Reports Server (NTRS)

    Podboy, Gary; Stephens, David

    2015-01-01

    Preliminary results are presented from a test conducted to determine how well microphone phased array processing software could pull an acoustic signal out of background noise. The array consisted of 24 microphones in an aerodynamic fairing designed to be mounted in-flow. The processing was conducted using Functional Beam forming software developed by Optinav combined with cross spectral matrix subtraction. The test was conducted in the free-jet of the Nozzle Acoustic Test Rig at NASA GRC. The background noise was produced by the interaction of the free-jet flow with the solid surfaces in the flow. The acoustic signals were produced by acoustic drivers. The results show that the phased array processing was able to pull the acoustic signal out of the background noise provided the signal was no more than 20 dB below the background noise level measured using a conventional single microphone equipped with an aerodynamic forebody.

  1. 50 years of progress in microphone arrays for speech processing

    NASA Astrophysics Data System (ADS)

    Elko, Gary W.; Frisk, George V.

    2004-10-01

    In the early 1980s, Jim Flanagan had a dream of covering the walls of a room with microphones. He occasionally referred to this concept as acoustic wallpaper. Being a new graduate in the field of acoustics and signal processing, it was fortunate that Bell Labs was looking for someone to investigate this area of microphone arrays for telecommunication. The job interview was exciting, with all of the big names in speech signal processing and acoustics sitting in the audience, many of whom were the authors of books and articles that were seminal contributions to the fields of acoustics and signal processing. If there ever was an opportunity of a lifetime, this was it. Fortunately, some of the work had already begun, and Sessler and West had already laid the groundwork for directional electret microphones. This talk will describe some of the very early work done at Bell Labs on microphone arrays and reflect on some of the many systems, from large 400-element arrays, to small two-microphone arrays. These microphone array systems were built under Jim Flanagan's leadership in an attempt to realize his vision of seamless hands-free speech communication between people and the communication of people with machines.

  2. The Signal Processing Firmware for the Low Frequency Aperture Array

    NASA Astrophysics Data System (ADS)

    Comoretto, Gianni; Chiello, Riccardo; Roberts, Matt; Halsall, Rob; Adami, Kristian Zarb; Alderighi, Monica; Aminaei, Amin; Baker, Jeremy; Belli, Carolina; Chiarucci, Simone; D’Angelo, Sergio; De Marco, Andrea; Mura, Gabriele Dalle; Magro, Alessio; Mattana, Andrea; Monari, Jader; Naldi, Giovanni; Pastore, Sandro; Perini, Federico; Poloni, Marco; Pupillo, Giuseppe; Rusticelli, Simone; Schiaffino, Marco; Schillirò, Francesco; Zaccaro, Emanuele

    The signal processing firmware that has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA) is described. The firmware is implemented on a dual FPGA board, that is capable of processing the streams from 16 dual polarization antennas. Data processing includes channelization of the sampled data for each antenna, correction for instrumental response and for geometric delays and formation of one or more beams by combining the aligned streams. The channelizer uses an oversampling polyphase filterbank architecture, allowing a frequency continuous processing of the input signal without discontinuities between spectral channels. Each board processes the streams from 16 antennas, as part of larger beamforming system, linked by standard Ethernet interconnections. These are envisaged to be 8192 of these signal processing platforms in the first phase of the SKA so particular attention has been devoted to ensure the design is low cost and low power.

  3. Parallel Processing of Large Scale Microphone Arrays for Sound Capture

    NASA Astrophysics Data System (ADS)

    Jan, Ea-Ee.

    1995-01-01

    Performance of microphone sound pick up is degraded by deleterious properties of the acoustic environment, such as multipath distortion (reverberation) and ambient noise. The degradation becomes more prominent in a teleconferencing environment in which the microphone is positioned far away from the speaker. Besides, the ideal teleconference should feel as easy and natural as face-to-face communication with another person. This suggests hands-free sound capture with no tether or encumbrance by hand-held or body-worn sound equipment. Microphone arrays for this application represent an appropriate approach. This research develops new microphone array and signal processing techniques for high quality hands-free sound capture in noisy, reverberant enclosures. The new techniques combine matched-filtering of individual sensors and parallel processing to provide acute spatial volume selectivity which is capable of mitigating the deleterious effects of noise interference and multipath distortion. The new method outperforms traditional delay-and-sum beamformers which provide only directional spatial selectivity. The research additionally explores truncated matched-filtering and random distribution of transducers to reduce complexity and improve sound capture quality. All designs are first established by computer simulation of array performance in reverberant enclosures. The simulation is achieved by a room model which can efficiently calculate the acoustic multipath in a rectangular enclosure up to a prescribed order of images. It also calculates the incident angle of the arriving signal. Experimental arrays were constructed and their performance was measured in real rooms. Real room data were collected in a hard-walled laboratory and a controllable variable acoustics enclosure of similar size, approximately 6 x 6 x 3 m. An extensive speech database was also collected in these two enclosures for future research on microphone arrays. The simulation results are shown to be

  4. Dimpled ball grid array process development for space flight applications

    NASA Technical Reports Server (NTRS)

    Barr, S. L.; Mehta, A.

    2000-01-01

    A 472 dimpled ball grid array (D-BGA) package has not been used in past space flight environments, therefore it was necessary to develop a process that would yield robust and reliable solder joints. The process developing assembly, inspection and rework techniques, were verified by conducting environmental tests. Since the 472 D-BGA packages passed the above environmental tests within the specifications, the process was successfully developed for space flight electronics.

  5. True-Time-Delay Adaptive Array Processing Using Photorefractive Crystals

    NASA Astrophysics Data System (ADS)

    Kriehn, G. R.; Wagner, K.

    Radio frequency (RF) signal processing has proven to be a fertile application area when using photorefractive-based, optical processing techniques. This is due to a photorefractive material's capability to record gratings and diffract off these gratings with optically modulated beams that contain a wide RF bandwidth, and include applications such as the bias-free time-integrating correlator [1], adaptive signal processing, and jammer excision, [2, 3, 4]. Photorefractive processing of signals from RF antenna arrays is especially appropriate because of the massive parallelism that is readily achievable in a photorefractive crystal (in which many resolvable beams can be incident on a single crystal simultaneously—each coming from an optical modulator driven by a separate RF antenna element), and because a number of approaches for adaptive array processing using photorefractive crystals have been successfully investigated [5, 6]. In these types of applications, the adaptive weight coefficients are represented by the amplitude and phase of the holographic gratings, and many millions of such adaptive weights can be multiplexed within the volume of a photorefractive crystal. RF modulated optical signals from each array element are diffracted from the adaptively recorded photorefractive gratings (which can be multiplexed either angularly or spatially), and are then coherently combined with the appropriate amplitude weights and phase shifts to effectively steer the angular receptivity pattern of the antenna array toward the desired arriving signal. Likewise, the antenna nulls can also be rotated toward unwanted narrowband jammers for extinction, thereby optimizing the signal-to-interference-plus-noise ratio.

  6. Electro-optical processing of phased-array antenna data

    NASA Technical Reports Server (NTRS)

    Casasent, D.; Casasayas, F.

    1975-01-01

    An on-line two-dimensional optical processor has been used to process simulated linear and planar phased-array radar data off-line but at real-time data rates. The input transducer is an electron-beam-addressed KD2PO4 light valve.

  7. Multisensor configurations for early sniper detection

    NASA Astrophysics Data System (ADS)

    Lindgren, D.; Bank, D.; Carlsson, L.; Dulski, R.; Duval, Y.; Fournier, G.; Grasser, R.; Habberstad, H.; Jacquelard, C.; Kastek, M.; Otterlei, R.; Piau, G.-P.; Pierre, F.; Renhorn, I.; Sjöqvist, L.; Steinvall, O.; Trzaskawka, P.

    2011-11-01

    This contribution reports some of the fusion results from the EDA SNIPOD project, where different multisensor configurations for sniper detection and localization have been studied. A project aim has been to cover the whole time line from sniper transport and establishment to shot. To do so, different optical sensors with and without laser illumination have been tested, as well as acoustic arrays and solid state projectile radar. A sensor fusion node collects detections and background statistics from all sensors and employs hypothesis testing and multisensor estimation programs to produce unified and reliable sniper alarms and accurate sniper localizations. Operator interfaces that connect to the fusion node should be able to support both sniper countermeasures and the guidance of personnel to safety. Although the integrated platform has not been actually built, sensors have been evaluated at common field trials with military ammunitions in the caliber range 5.56 to 12.7 mm, and at sniper distances up to 900 m. It is concluded that integrating complementary sensors for pre- and postshot sniper detection in a common system with automatic detection and fusion will give superior performance, compared to stand alone sensors. A practical system is most likely designed with a cost effective subset of available complementary sensors.

  8. HALO: a reconfigurable image enhancement and multisensor fusion system

    NASA Astrophysics Data System (ADS)

    Wu, F.; Hickman, D. L.; Parker, Steve J.

    2014-06-01

    Contemporary high definition (HD) cameras and affordable infrared (IR) imagers are set to dramatically improve the effectiveness of security, surveillance and military vision systems. However, the quality of imagery is often compromised by camera shake, or poor scene visibility due to inadequate illumination or bad atmospheric conditions. A versatile vision processing system called HALO™ is presented that can address these issues, by providing flexible image processing functionality on a low size, weight and power (SWaP) platform. Example processing functions include video distortion correction, stabilisation, multi-sensor fusion and image contrast enhancement (ICE). The system is based around an all-programmable system-on-a-chip (SoC), which combines the computational power of a field-programmable gate array (FPGA) with the flexibility of a CPU. The FPGA accelerates computationally intensive real-time processes, whereas the CPU provides management and decision making functions that can automatically reconfigure the platform based on user input and scene content. These capabilities enable a HALO™ equipped reconnaissance or surveillance system to operate in poor visibility, providing potentially critical operational advantages in visually complex and challenging usage scenarios. The choice of an FPGA based SoC is discussed, and the HALO™ architecture and its implementation are described. The capabilities of image distortion correction, stabilisation, fusion and ICE are illustrated using laboratory and trials data.

  9. Frequency-wavenumber processing for infrasound distributed arrays.

    PubMed

    Costley, R Daniel; Frazier, W Garth; Dillion, Kevin; Picucci, Jennifer R; Williams, Jay E; McKenna, Mihan H

    2013-10-01

    The work described herein discusses the application of a frequency-wavenumber signal processing technique to signals from rectangular infrasound arrays for detection and estimation of the direction of travel of infrasound. Arrays of 100 sensors were arranged in square configurations with sensor spacing of 2 m. Wind noise data were collected at one site. Synthetic infrasound signals were superposed on top of the wind noise to determine the accuracy and sensitivity of the technique with respect to signal-to-noise ratio. The technique was then applied to an impulsive event recorded at a different site. Preliminary results demonstrated the feasibility of this approach.

  10. On a single step technique for adaptive array processing

    NASA Astrophysics Data System (ADS)

    Worms, Josef

    1986-07-01

    An improved adaptation algorithm designed for real time signal processing in antenna arrays is presented. The method is used for determining the filter weights in a sidelobe cancellation system. The Wiener filter equation is solved by using the well known Gauss-Seidel method and a sample matrix estimate. This algorithm (SSM - Single Step Method) combines rapid convergence and numerical stability. Compared with the direct SMI-technique and the Widrow LMS-algorithm, the properties of the proposed algorithm lead us to the conclusion that it is especially well suited for airborne antenna array applications.

  11. The Applicability of Incoherent Array Processing to IMS Seismic Array Stations

    NASA Astrophysics Data System (ADS)

    Gibbons, S. J.

    2012-04-01

    The seismic arrays of the International Monitoring System for the CTBT differ greatly in size and geometry, with apertures ranging from below 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high frequency phases since signals are often incoherent between sensors. Many such phases, typically from events at regional distances, remain undetected since pipeline algorithms often consider only frequencies low enough to allow coherent array processing. High frequency phases that are detected are frequently attributed qualitatively incorrect backazimuth and slowness estimates and are consequently not associated with the correct event hypotheses. This can lead to missed events both due to a lack of contributing phase detections and by corruption of event hypotheses by spurious detections. Continuous spectral estimation can be used for phase detection and parameter estimation on the largest aperture arrays, with phase arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity and the ability to estimate backazimuth and slowness requires that the spatial extent of the array is large enough to resolve time-delays between envelopes with a period of approximately 4 or 5 seconds. The NOA, AKASG, YKA, WRA, and KURK arrays have apertures in excess of 20 km and spectrogram beamforming on these stations provides high quality slowness estimates for regional phases without additional post-processing. Seven arrays with aperture between 10 and 20 km (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 second period signal. The MJAR array in Japan recorded high SNR Pn signals for both the 2006 and 2009 North Korea

  12. Large-Array Signal Processing for Deep-Space Applications

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Vilnrotter, V.; Satorius, E.; Ye, Z.; Fort, D.; Cheung, K.-M.

    2002-04-01

    This article develops the mathematical models needed to describe the key issues in using an array of antennas for receiving spacecraft signals for DSN applications. The detrimental effects of nearby interfering sources, such as other spacecraft transmissions or natural radio sources within the array's field of view, on signal-to noise ratio (SNR) are determined, atmospheric effects relevant to the arraying problem developed, and two classes of algorithms (multiple signal classification (MUSIC) plus beam forming, and an eigen-based solution) capable of phasing up the array with maximized SNR in the presence of realistic disturbances are evaluated. It is shown that, when convolutionally encoded binary-phase shift keying (BPSK) data modulation is employed on the spacecraft signal, previously developed data pre-processing techniques that partially reconstruct the carrier can be of great benefit to array performance, particularly when strong interfering sources are present. Since this article is concerned mainly with demonstrating the required capabilities for operation under realistic conditions, no attempt has been made to reduce algorithm complexity; the design and evaluation of less complex algorithms with similar capabilities will be addressed in a future article. The performances of the candidate algorithms discussed in this article have been evaluated in terms of the number of symbols needed to achieve a given level of combining loss for different numbers of array elements, and compared on this common basis. It is shown that even the best algorithm requires approximately 25,000 symbols to achieve a combining loss of less than 0.5 dB when 128 antenna elements are employed, but generally 50,000 or more symbols are needed. This is not a serious impediment to successful arraying with high data-rate transmission, but may be of some concern with missions exploring near the edge of our solar system or beyond, where lower data rates may be required.

  13. Application of Seismic Array Processing to Earthquake Early Warning

    NASA Astrophysics Data System (ADS)

    Meng, L.; Allen, R. M.; Ampuero, J. P.

    2013-12-01

    Earthquake early warning (EEW) systems that can issue warnings prior to the arrival of strong ground shaking during an earthquake are essential in mitigating seismic hazard. Many of the currently operating EEW systems work on the basis of empirical magnitude-amplitude/frequency scaling relations for a point source. This approach is of limited effectiveness for large events, such as the 2011 Tohoku-Oki earthquake, for which ignoring finite source effects may result in underestimation of the magnitude. Here, we explore the concept of characterizing rupture dimensions in real time for EEW using clusters of dense low-cost accelerometers located near active faults. Back tracing the waveforms recorded by such arrays allows the estimation of the earthquake rupture size, duration and directivity in real-time, which enables the EEW of M > 7 earthquakes. The concept is demonstrated with the 2004 Parkfield earthquake, one of the few big events (M>6) that have been recorded by a local small-scale seismic array (UPSAR array, Fletcher et al, 2006). We first test the approach against synthetic rupture scenarios constructed by superposition of empirical Green's functions. We find it important to correct for the bias in back azimuth induced by dipping structures beneath the array. We implemented the proposed methodology to the mainshock in a simulated real-time environment. After calibrating the dipping-layer effect with data from smaller events, we obtained an estimated rupture length of 9 km, consistent with the distance between the two main high frequency subevents identified by back-projection using all local stations (Allman and Shearer, 2007). We proposed to deploy small-scale arrays every 30 km along the San Andreas Fault. The array processing is performed in local processing centers at each array. The output is compared with finite fault solutions based on real-time GPS system and then incorporated into the standard ElarmS system. The optimal aperture and array geometry is

  14. Fabrication of Linear Array and Top-Orthogonal-to-Bottom Electrode CMUT Arrays With a Sacrificial Release Process.

    PubMed

    Greenlay, Benjamin A; Zemp, Roger J

    2017-01-01

    The microfabrication processes for sacrificial-release-based capacitive micromachined ultrasound transducer arrays are provided with an emphasis on top-orthogonal-to-bottom electrode 2-D arrays. These arrays have significant promise for high-quality 3-D imaging with reduced wiring complexity compared with fully wired arrays. The protocols and best practices are outlined in significant detail along with design considerations and notes of caution for pitfalls and factors impacting yield.

  15. Fabrication of Linear Array and Top-Orthogonal-to-Bottom Electrode (TOBE) CMUT Arrays with a Sacrificial Release Process.

    PubMed

    Greenlay, Benjamin; Zemp, Roger

    2016-10-24

    The microfabrication processes for sacrificial-release based capacitive micromachined ultrasound transducer (CMUT) arrays are provided with an emphasis on top-orthogonal-to-bottom electrode (TOBE) 2D arrays. These arrays have significant promise for high-quality 3D imaging with reduced wiring complexity compared to fully-wired arrays. The protocols and best practices are outlined in significant detail along with design considerations and notes of caution for pitfalls and factors impacting yield.

  16. IN-SITU IONIC CHEMICAL ANALYSIS OF FRESH WATER VIA A NOVEL COMBINED MULTI-SENSOR / SIGNAL PROCESSING ARCHITECTURE

    NASA Astrophysics Data System (ADS)

    Mueller, A. V.; Hemond, H.

    2009-12-01

    The capability for comprehensive, real-time, in-situ characterization of the chemical constituents of natural waters is a powerful tool for the advancement of the ecological and geochemical sciences, e.g. by facilitating rapid high-resolution adaptive sampling campaigns and avoiding the potential errors and high costs related to traditional grab sample collection, transportation and analysis. Portable field-ready instrumentation also promotes the goals of large-scale monitoring networks, such as CUASHI and WATERS, without the financial and human resources overhead required for traditional sampling at this scale. Problems of environmental remediation and monitoring of industrial waste waters would additionally benefit from such instrumental capacity. In-situ measurement of all major ions contributing to the charge makeup of natural fresh water is thus pursued via a combined multi-sensor/multivariate signal processing architecture. The instrument is based primarily on commercial electrochemical sensors, e.g. ion selective electrodes (ISEs) and ion selective field-effect transistors (ISFETs), to promote low cost as well as easy maintenance and reproduction,. The system employs a novel architecture of multivariate signal processing to extract accurate information from in-situ data streams via an "unmixing" process that accounts for sensor non-linearities at low concentrations, as well as sensor cross-reactivities. Conductivity, charge neutrality and temperature are applied as additional mathematical constraints on the chemical state of the system. Including such non-ionic information assists in obtaining accurate and useful calibrations even in the non-linear portion of the sensor response curves, and measurements can be made without the traditionally-required standard additions or ionic strength adjustment. Initial work demonstrates the effectiveness of this methodology at predicting inorganic cations (Na+, NH4+, H+, Ca2+, and K+) in a simplified system containing

  17. Processing difficulties and instability of carbohydrate microneedle arrays

    PubMed Central

    Donnelly, Ryan F.; Morrow, Desmond I.J.; Singh, Thakur R.R.; Migalska, Katarzyna; McCarron, Paul A.; O’Mahony, Conor; Woolfson, A. David

    2010-01-01

    Background A number of reports have suggested that many of the problems currently associated with the use of microneedle (MN) arrays for transdermal drug delivery could be addressed by using drug-loaded MN arrays prepared by moulding hot melts of carbohydrate materials. Methods In this study, we explored the processing, handling, and storage of MN arrays prepared from galactose with a view to clinical application. Results Galactose required a high processing temperature (160°C), and molten galactose was difficult to work with. Substantial losses of the model drugs 5-aminolevulinic acid (ALA) and bovine serum albumin were incurred during processing. While relatively small forces caused significant reductions in MN height when applied to an aluminium block, this was not observed during their relatively facile insertion into heat-stripped epidermis. Drug release experiments using ALA-loaded MN arrays revealed that less than 0.05% of the total drug loading was released across a model silicone membrane. Similarly, only low amounts of ALA (approximately 0.13%) and undetectable amounts of bovine serum albumin were delivered when galactose arrays were combined with aqueous vehicles. Microscopic inspection of the membrane following release studies revealed that no holes could be observed in the membrane, indicating that the partially dissolved galactose sealed the MN-induced holes, thus limiting drug delivery. Indeed, depth penetration studies into excised porcine skin revealed that there was no significant increase in ALA delivery using galactose MN arrays, compared to control (P value < 0.05). Galactose MNs were unstable at ambient relative humidities and became adhesive. Conclusion The processing difficulties and instability encountered in this study are likely to preclude successful clinical application of carbohydrate MNs. The findings of this study are of particular importance to those in the pharmaceutical industry involved in the design and formulation of

  18. Utilizing Multi-Sensor Data Products and high-resolution flood model in Analyzing North African Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Thengumthara, K.; Policelli, F.; Habib, S.; David, J. L.; Melocik, K. A.; Huffman, G. J.; Anderson, M. C.; Ali, A. B.; Bacha, S.

    2013-12-01

    North Africa is an arid region characterized by isolated extreme events such as floods and droughts. Our present understanding of hydrological processes over North Africa is limited due to low rainfall, mixed response of evaporation to temperature and soil moisture gradients, and lack of high-resolution ground measurements. Remote sensing is an excellent way to obtain near real- time data of high spatial and temporal resolution. Satellite estimates of rainfall and evapotranspiration (ET) have uncertainties due to topography, land-sea contrast, complex weather, and climate variability for high-elevated regions. Generally for arid regions, the satellite precipitation instruments are sensitive to soil moisture and land surface geometry. This study analyzes different components of hydrological processes over North Africa based on remote sensing data such as precipitation (NASA-TMPA, CMORPH and PERSIANN), evaporation (ALEXI and MODIS), and elevation (SRTM) along with ground measurements and model simulations. Here we use the Coupled Routing and Excess STorage (CREST) hydrological model-version 2.0, which was originally developed by NASA-GSFC and the University of Oklahoma [Wang J et al., 2011]. The model is driven by real time TMPA and climatological PET, interpolated to model grids. The flexible simulation and calibration enables the model to provide high-resolution runoff and water depth at each time step. Our study mainly focuses on two major basins such as Medjerda over Tunisia and the Sebou basin of Morocco. Case studies of flood events over North Africa were analyzed based on CREST model simulations with respect to ground measurements. The floods are mainly modulated by rainfall associated with synoptic frontal and tropical plumes and orographic mesoscale systems. Occurrences of peak floods simulated by CREST are comparable with diagnostics such as vertically integrated moisture convergence, stratiform and convective precipitation from ECMWF reanalysis. These were

  19. Advancing archaeological geophysics: Interpreting the archaeological landscape, ground-penetrating radar data processing, and multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Ernenwein, Eileen G.

    The human past has been the subject of scientific inquiry for centuries, and has long been approached by the study of material remains from traditional archaeological excavations. In recent decades the advancing fields of geophysics and geographic information systems have greatly improved the archaeological toolkit, and research to improve these methods is ongoing. This dissertation focuses on important aspects of geophysical survey as an approach to landscape-scale archaeology, each presented as stand-alone scientific papers that utilize a 1.2 hectare four-dimensional (ground-penetrating radar, magnetometry, magnetic susceptibility, and conductivity) dataset collected at Pueblo Escondido, a large prehistoric village of the Mogollon culture in southern New Mexico. Chapter 2 presents a case study showing the benefits of multidimensional geophysical surveys over large areas at archaeological sites. When paired with traditional archaeological excavations, it is possible to interpret the archaeological landscape on a much broader scale than is possible using excavations alone. At Pueblo Escondido, this approach led to a revised understanding of the architectural remains with broad regional significance. Chapter 3 describes new problems related to GPR surveys over large areas or extended periods of time, including issues related to correcting trace misalignments, edge discontinuities, and striping. Data processing solutions are offered. Chapter 4 presents an exploration of image classification methods for integrating multiple geophysical datasets. Unsupervised classification utilizing K-means cluster analysis and supervised classification using Mahalanobis Distance are described. The latter yielded a predictive model of archaeological features and identified some features that were not easily identified in the original datasets.

  20. Vehicle passes detector based on multi-sensor analysis

    NASA Astrophysics Data System (ADS)

    Bocharov, D.; Sidorchuk, D.; Konovalenko, I.; Koptelov, I.

    2015-02-01

    The study concerned deals with a new approach to the problem of detecting vehicle passes in vision-based automatic vehicle classification system. Essential non-affinity image variations and signals from induction loop are the events that can be considered as detectors of an object presence. We propose several vehicle detection techniques based on image processing and induction loop signal analysis. Also we suggest a combined method based on multi-sensor analysis to improve vehicle detection performance. Experimental results in complex outdoor environments show that the proposed multi-sensor algorithm is effective for vehicles detection.

  1. Breath alcohol, multisensor arrays, and electronic noses

    NASA Astrophysics Data System (ADS)

    Paulsson, Nils; Winquist, Fredrik

    1997-01-01

    The concept behind a volatile compound mapper, or electronic nose, is to use the combination of multiple gas sensors and pattern recognition techniques to detect and quantify substances in gas mixtures. There are several different kinds of sensors which have been developed during recent years of which the base techniques are conducting polymers, piezo electrical crystals and solid state devices. In this work we have used a combination of gas sensitive field effect devices and semiconducting metal oxides. The most useful pattern recognition routine was found to be ANNs, which is a mathematical approximation of the human neural network. The aim of this work is to evaluate the possibility of using electronic noses in field instruments to detect drugs, arson residues, explosives etc. As a test application we have chosen breath alcohol measurements. There are several reasons for this. Breath samples are a quite complex mixture contains between 200 and 300 substances at trace levels. The alcohol level is low but still possible to handle. There are needs for replacing large and heavy mobile instruments with smaller devices. Current instrumentation is rather sensitive to interfering substances. The work so far has dealt with sampling, how to introduce ethanol and other substances in the breath, correlation measurements between the electronic nose and headspace GC, and how to evaluate the sensor signals.

  2. Application of Multi-Sensor Information Fusion Method Based on Rough Sets and Support Vector Machine

    NASA Astrophysics Data System (ADS)

    Xue, Jinxue; Wang, Guohu; Wang, Xiaoqiang; Cui, Fengkui

    In order to improve the precision and date processing speed of multi-sensor information fusion, a kind of multi-sensor data fusion process algorithm has been studied in this paper. First, based on rough set theory (RS) to attribute reduction the parameter set, we use the advantages of rough set theory in dealing with large amount of data to eliminate redundant information. Then, the data can be trained and classified by Support Vector Machine (SYM). Experimental results showed that this method can improve the speed and accuracy of multi-sensor fusion system.

  3. Multi-sensor analysis of urban ecosystems

    USGS Publications Warehouse

    Gallo, K.; Ji, L.

    2004-01-01

    This study examines the synthesis of multiple space-based sensors to characterize the urban environment Single scene data (e.g., ASTER visible and near-IR surface reflectance, and land surface temperature data), multi-temporal data (e.g., one year of 16-day MODIS and AVHRR vegetation index data), and DMSP-OLS nighttime light data acquired in the early 1990s and 2000 were evaluated for urban ecosystem analysis. The advantages of a multi-sensor approach for the analysis of urban ecosystem processes are discussed.

  4. Multisensor Data Integration Techniques

    NASA Technical Reports Server (NTRS)

    Evans, D. L.; Blake, P. L.; Conel, J. E.; Lang, H. R.; Logan, T. L.; Mcguffie, B. A.; Paylor, E. D.; Singer, R. B.; Schenck, L. R.

    1985-01-01

    The availability of data from sensors operating in several different wavelength regions had led to the development of new techniques and strategies for both data management and image analysis. Work is ongoing to develop computer techniques for analysis of integrated data sets. These techniques include coregistration of multisensor images, rectification of radar images in areas of topographic relief to ensure pixel to pixel registration with planimetric data sets, calibration of data so that signatures can be applied to remote areas, normalization of data acquired with disparate sensors and determination of extended spectral signatures of surface units. In addition, software is being developed to analyze coregistrated digital terrain and image data so that automated stratigraphic and structural analyses can be performed. These software procedures include: strike and dip determination, terrain profile generation, stratigraphic column generation, stratigraphic thickness measurements, structural cross-section generation, and creation of 3-D block diagrams. These techniques were applied to coregistered LANDSAT 4 Thematic Mapper (TM), Thermal Infrared Multispectral Scanner (TIMS), and multipolarization synthetic aperture radar (SAR) data of the Wind River Basin in Wyoming.

  5. Multisensor Fire Observations

    NASA Technical Reports Server (NTRS)

    Boquist, C.

    2004-01-01

    This DVD includes animations of multisensor fire observations from the following satellite sources: Landsat, GOES, TOMS, Terra, QuikSCAT, and TRMM. Some of the animations are included in multiple versions of a short video presentation on the DVD which focuses on the Hayman, Rodeo-Chediski, and Biscuit fires during the 2002 North American fire season. In one version of the presentation, MODIS, TRMM, GOES, and QuikSCAT data are incorporated into the animations of these wildfires. These data products provided rain, wind, cloud, and aerosol data on the fires, and monitored the smoke and destruction created by them. Another presentation on the DVD consists of a panel discussion, in which experts from academia, NASA, and the U.S. Forest Service answer questions on the role of NASA in fighting forest fires, the role of the Terra satellite and its instruments, including the Moderate Resolution Imaging Spectroradiometer (MODIS), in fire fighting decision making, and the role of fire in the Earth's climate. The third section of the DVD features several animations of fires over the years 2001-2003, including animations of global and North American fires, and specific fires from 2003 in California, Washington, Montana, and Arizona.

  6. Multisensor Fire Observations

    NASA Technical Reports Server (NTRS)

    Boquist, C.

    2004-01-01

    This DVD includes animations of multisensor fire observations from the following satellite sources: Landsat, GOES, TOMS, Terra, QuikSCAT, and TRMM. Some of the animations are included in multiple versions of a short video presentation on the DVD which focuses on the Hayman, Rodeo-Chediski, and Biscuit fires during the 2002 North American fire season. In one version of the presentation, MODIS, TRMM, GOES, and QuikSCAT data are incorporated into the animations of these wildfires. These data products provided rain, wind, cloud, and aerosol data on the fires, and monitored the smoke and destruction created by them. Another presentation on the DVD consists of a panel discussion, in which experts from academia, NASA, and the U.S. Forest Service answer questions on the role of NASA in fighting forest fires, the role of the Terra satellite and its instruments, including the Moderate Resolution Imaging Spectroradiometer (MODIS), in fire fighting decision making, and the role of fire in the Earth's climate. The third section of the DVD features several animations of fires over the years 2001-2003, including animations of global and North American fires, and specific fires from 2003 in California, Washington, Montana, and Arizona.

  7. Real-time signal processing with FPS array processors

    SciTech Connect

    Higginbotham, R.E.; Wiley, P.G.

    1980-01-01

    The authors discuss real-time signal processing with the FPS programmable array processor (AP). This AP is designed to attach as a peripheral device to a host machine, either a minicomputer or mainframe. The basic AP consists of a host interface, multiple independent memories, parallel pipelined floating-point adder and multiplier, and a control/integer processing unit. For real-time signal processing applications in which the throughput rate exceeds the capability of the host computer, independent input/output (I/O) interfaces are available which provide direct access to the AP for external input and output devices. 2 references.

  8. Signal processing on the focal plane array: an overview

    NASA Astrophysics Data System (ADS)

    Graham, Roger W.; Trautfield, Walter C.; Taylor, Scott M.; Murray, Mark P.; Mesh, Frank J.; Horn, Stuart B.; Finch, James A.; Dang, Khoa V.; Caulfield, John T.

    2000-12-01

    Raytheon's Infrared Operations (RIO) has invented and developed a new class of focal plane arrays; the Adaptive IR Sensor (AIRS) and Thinfilm Analog Image Processor (TAIP). The AIRS FPA is based upon biologically inspired on-focal- plane circuitry, which adaptively removes detector and optic temperature drift and l/f induced fixed pattern noise. This third-generation multimode IRFPA, also called a Smart FPA, is a 256x256-array format capable of operation in four modes: 1) Direct Injection (DI), 2) Adaptive Non-uniformity Correction (NUC), 3) Motion/Edge Detection, and 4) Subframe Averaging. Also the 320x240 TAIP results have shown excellent image processing in the form of Spatial and Temporal processing.

  9. Signal Processing for a Lunar Array: Minimizing Power Consumption

    NASA Technical Reports Server (NTRS)

    D'Addario, Larry; Simmons, Samuel

    2011-01-01

    Motivation for the study is: (1) Lunar Radio Array for low frequency, high redshift Dark Ages/Epoch of Reionization observations (z =6-50, f=30-200 MHz) (2) High precision cosmological measurements of 21 cm H I line fluctuations (3) Probe universe before first star formation and provide information about the Intergalactic Medium and evolution of large scale structures (5) Does the current cosmological model accurately describe the Universe before reionization? Lunar Radio Array is for (1) Radio interferometer based on the far side of the moon (1a) Necessary for precision measurements, (1b) Shielding from earth-based and solar RFI (12) No permanent ionosphere, (2) Minimum collecting area of approximately 1 square km and brightness sensitivity 10 mK (3)Several technologies must be developed before deployment The power needed to process signals from a large array of nonsteerable elements is not prohibitive, even for the Moon, and even in current technology. Two different concepts have been proposed: (1) Dark Ages Radio Interferometer (DALI) (2)( Lunar Array for Radio Cosmology (LARC)

  10. Signal Processing for a Lunar Array: Minimizing Power Consumption

    NASA Technical Reports Server (NTRS)

    D'Addario, Larry; Simmons, Samuel

    2011-01-01

    Motivation for the study is: (1) Lunar Radio Array for low frequency, high redshift Dark Ages/Epoch of Reionization observations (z =6-50, f=30-200 MHz) (2) High precision cosmological measurements of 21 cm H I line fluctuations (3) Probe universe before first star formation and provide information about the Intergalactic Medium and evolution of large scale structures (5) Does the current cosmological model accurately describe the Universe before reionization? Lunar Radio Array is for (1) Radio interferometer based on the far side of the moon (1a) Necessary for precision measurements, (1b) Shielding from earth-based and solar RFI (12) No permanent ionosphere, (2) Minimum collecting area of approximately 1 square km and brightness sensitivity 10 mK (3)Several technologies must be developed before deployment The power needed to process signals from a large array of nonsteerable elements is not prohibitive, even for the Moon, and even in current technology. Two different concepts have been proposed: (1) Dark Ages Radio Interferometer (DALI) (2)( Lunar Array for Radio Cosmology (LARC)

  11. Estimates of Crustal Transmission Losses Using MLM Array Processing.

    DTIC Science & Technology

    1982-07-01

    Continue on rovereo de II neceery, end Identfip by block nuinbe.) 1. Array processing 2. Acoustic transmission loss 3. MLM beamforming 20. AUSTRACT...Baggeroer and Falconer,1981). The technique conceptually designs a beamformer based on the input data (hence data adaptive). This beamformer minimizes...output power with the constraint that energy from a specific direction is passed undistorted. We shall see that the structure of this beamformer can be

  12. TRIGA: Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Pang, Jackson; Pingree, Paula J.; Torgerson, J. Leigh

    2006-01-01

    We present the Telecommunications protocol processing subsystem using Reconfigurable Interoperable Gate Arrays (TRIGA), a novel approach that unifies fault tolerance, error correction coding and interplanetary communication protocol off-loading to implement CCSDS File Delivery Protocol and Datalink layers. The new reconfigurable architecture offers more than one order of magnitude throughput increase while reducing footprint requirements in memory, command and data handling processor utilization, communication system interconnects and power consumption.

  13. Performance of redundant disk array organizations in transaction processing environments

    NASA Technical Reports Server (NTRS)

    Mourad, Antoine N.; Fuchs, W. K.; Saab, Daniel G.

    1993-01-01

    A performance evaluation is conducted for two redundant disk-array organizations in a transaction-processing environment, relative to the performance of both mirrored disk organizations and organizations using neither striping nor redundancy. The proposed parity-striping alternative to striping with rotated parity is shown to furnish rapid recovery from failure at the same low storage cost without interleaving the data over multiple disks. Both noncached systems and systems using a nonvolatile cache as the controller are considered.

  14. Physics-based signal processing algorithms for micromachined cantilever arrays

    DOEpatents

    Candy, James V; Clague, David S; Lee, Christopher L; Rudd, Robert E; Burnham, Alan K; Tringe, Joseph W

    2013-11-19

    A method of using physics-based signal processing algorithms for micromachined cantilever arrays. The methods utilize deflection of a micromachined cantilever that represents the chemical, biological, or physical element being detected. One embodiment of the method comprises the steps of modeling the deflection of the micromachined cantilever producing a deflection model, sensing the deflection of the micromachined cantilever and producing a signal representing the deflection, and comparing the signal representing the deflection with the deflection model.

  15. Superresolution with Seismic Arrays using Empirical Matched Field Processing

    SciTech Connect

    Harris, D B; Kvaerna, T

    2010-03-24

    Scattering and refraction of seismic waves can be exploited with empirical matched field processing of array observations to distinguish sources separated by much less than the classical resolution limit. To describe this effect, we use the term 'superresolution', a term widely used in the optics and signal processing literature to denote systems that break the diffraction limit. We illustrate superresolution with Pn signals recorded by the ARCES array in northern Norway, using them to identify the origins with 98.2% accuracy of 549 explosions conducted by closely-spaced mines in northwest Russia. The mines are observed at 340-410 kilometers range and are separated by as little as 3 kilometers. When viewed from ARCES many are separated by just tenths of a degree in azimuth. This classification performance results from an adaptation to transient seismic signals of techniques developed in underwater acoustics for localization of continuous sound sources. Matched field processing is a potential competitor to frequency-wavenumber and waveform correlation methods currently used for event detection, classification and location. It operates by capturing the spatial structure of wavefields incident from a particular source in a series of narrow frequency bands. In the rich seismic scattering environment, closely-spaced sources far from the observing array nonetheless produce distinct wavefield amplitude and phase patterns across the small array aperture. With observations of repeating events, these patterns can be calibrated over a wide band of frequencies (e.g. 2.5-12.5 Hertz) for use in a power estimation technique similar to frequency-wavenumber analysis. The calibrations enable coherent processing at high frequencies at which wavefields normally are considered incoherent under a plane wave model.

  16. TRIGA: Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Pang, Jackson; Pingree, Paula J.; Torgerson, J. Leigh

    2006-01-01

    We present the Telecommunications protocol processing subsystem using Reconfigurable Interoperable Gate Arrays (TRIGA), a novel approach that unifies fault tolerance, error correction coding and interplanetary communication protocol off-loading to implement CCSDS File Delivery Protocol and Datalink layers. The new reconfigurable architecture offers more than one order of magnitude throughput increase while reducing footprint requirements in memory, command and data handling processor utilization, communication system interconnects and power consumption.

  17. Navigation in Difficult Environments: Multi-Sensor Fusion Techniques

    DTIC Science & Technology

    2010-03-01

    data are applied to improve the robustness of secondary sensors’ signal processing. Applications of the multi-sensor fusion approach are illustrated...algorithms. 1.0 MOTIVATION Many existing and perspective applications of navigation systems would benefit notably from the ability to navigate...accurately and reliably in difficult environments. Examples of difficult navigation scenarios include urban canyons, indoor applications , radio

  18. Enhancement of data analysis through multisensor data fusion technology

    USDA-ARS?s Scientific Manuscript database

    This paper focuses on application of multisensor data fusion for high quality data analysis and processing in measurement and instrumentation. A practical, general data fusion scheme is established on the basis of feature extraction and merging of data from multiple sensors. This scheme integrates...

  19. The Multi-sensor Airborne Radiation Survey (MARS) instrument

    NASA Astrophysics Data System (ADS)

    Fast, J. E.; Aalseth, C. E.; Asner, D. M.; Bonebrake, C. A.; Day, A. R.; Dorow, K. E.; Fuller, E. S.; Glasgow, B. D.; Hossbach, T. W.; Hyronimus, B. J.; Jensen, J. L.; Johnson, K. I.; Jordan, D. V.; Morgen, G. P.; Morris, S. J.; Mullen, O. D.; Myers, A. W.; Pitts, W. K.; Rohrer, J. S.; Runkle, R. C.; Seifert, A.; Shergur, J. M.; Stave, S. C.; Tatishvili, G.; Thompson, R. C.; Todd, L. C.; Warren, G. A.; Willett, J. A.; Wood, L. S.

    2013-01-01

    The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gama ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach is necessary since a high efficiency HPGe detector can only be built as an array due to limitations in growing large germanium crystals. The system is ruggedized and shock mounted for use in a variety of field applications, including airborne and maritime operations.

  20. The Multi-sensor Airborne Radiation Survey (MARS) Instrument

    SciTech Connect

    Fast, James E.; Aalseth, Craig E.; Asner, David M.; Bonebrake, Christopher A.; Day, Anthony R.; Dorow, Kevin E.; Fuller, Erin S.; Glasgow, Brian D.; Hossbach, Todd W.; Hyronimus, Brian J.; Jensen, Jeffrey L.; Johnson, Kenneth I.; Jordan, David V.; Morgen, Gerald P.; Morris, Scott J.; Mullen, O Dennis; Myers, Allan W.; Pitts, W. Karl; Rohrer, John S.; Runkle, Robert C.; Seifert, Allen; Shergur, Jason M.; Stave, Sean C.; Tatishvili, Gocha; Thompson, Robert C.; Todd, Lindsay C.; Warren, Glen A.; Willett, Jesse A.; Wood, Lynn S.

    2013-01-11

    The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gama ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach, we found, is necessary since a high efficiency HPGe detector can only be built as an array due to limitations in growing large germanium crystals. Moreover, the system is ruggedized and shock mounted for use in a variety of field applications, including airborne and maritime operations.

  1. Principles of data-fusion in multi-sensor systems for non-destructive testing

    NASA Astrophysics Data System (ADS)

    Chioclea, Shmuel; Dickstein, Phineas

    2000-05-01

    In recent years, there has been progress in the application of measurement and control systems that engage multi-sensor arrays. Several algorithms and techniques have been developed for the integration of the information obtained from the sensors. The fusion of the data may be complicated due to the fact that each sensor has its own performance characteristics, and because different sensors may detect different physical phenomena. As a result, data fusion turns out to be a multidisciplinary field, which applies principles adopted from other fields such as signal processing, artificial intelligence, statistics, and The Theory of Information. The data fusion machine tries to imitate the human brain, in combining data from numerous sensors and making optimal inferences about the environment. The present paper provides a critical review of data fusion algorithms and techniques and a trenchant summary of the experience gained to date from the several preliminary NDT studies which have been applying multi-sensor data fusion systems. Consequently, this paper provides a list of rules and criteria to be followed in future applications of data fusion to nondestructive testing.

  2. A Time Integrating Optical Correlator for Adaptive Array Processing.

    DTIC Science & Technology

    1982-12-01

    AD-A124 672 A TIME INTEGRATING OPT1CRL CORRELATOR FOR ADAPTIVE / RRAYV PROCESSING(U) AIR FORCE INST OF TECH IRIGHT-PATTERSON AFB OH SCHOOL OF...di3tdbutbon i- , " . DEPARTMENT OF THE AIR FORCE aAIR UNIVERSITY (ATC) AIR FORCE INSTITUTE OF TECHNOLOGY LUJ._ Wright-Patterson Air Force Base, Ohio 8 3 02...OPTICAL CORRELATOR FOR ADAPTIVE ARRAY PROCESSING THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology Air

  3. Flat-plate solar array project. Volume 5: Process development

    NASA Technical Reports Server (NTRS)

    Gallagher, B.; Alexander, P.; Burger, D.

    1986-01-01

    The goal of the Process Development Area, as part of the Flat-Plate Solar Array (FSA) Project, was to develop and demonstrate solar cell fabrication and module assembly process technologies required to meet the cost, lifetime, production capacity, and performance goals of the FSA Project. R&D efforts expended by Government, Industry, and Universities in developing processes capable of meeting the projects goals during volume production conditions are summarized. The cost goals allocated for processing were demonstrated by small volume quantities that were extrapolated by cost analysis to large volume production. To provide proper focus and coverage of the process development effort, four separate technology sections are discussed: surface preparation, junction formation, metallization, and module assembly.

  4. Information Measures for Multisensor Systems

    DTIC Science & Technology

    2013-12-11

    permuted to generate spectra that were non- physical but preserved the entropy of the source spectra. Another 1000 spectra were constructed to mimic co...Research Laboratory (NRL) has yielded probabilistic models for spectral data that enable the computation of information measures such as entropy and...22308 Chemical sensing Information theory Spectral data Information entropy Information divergence Mass spectrometry Infrared spectroscopy Multisensor

  5. Multisensor classification of sedimentary rocks

    NASA Technical Reports Server (NTRS)

    Evans, Diane

    1988-01-01

    A comparison is made between linear discriminant analysis and supervised classification results based on signatures from the Landsat TM, the Thermal Infrared Multispectral Scanner (TIMS), and airborne SAR, alone and combined into extended spectral signatures for seven sedimentary rock units exposed on the margin of the Wind River Basin, Wyoming. Results from a linear discriminant analysis showed that training-area classification accuracies based on the multisensor data were improved an average of 15 percent over TM alone, 24 percent over TIMS alone, and 46 percent over SAR alone, with similar improvement resulting when supervised multisensor classification maps were compared to supervised, individual sensor classification maps. When training area signatures were used to map spectrally similar materials in an adjacent area, the average classification accuracy improved 19 percent using the multisensor data over TM alone, 2 percent over TIMS alone, and 11 percent over SAR alone. It is concluded that certain sedimentary lithologies may be accurately mapped using a single sensor, but classification of a variety of rock types can be improved using multisensor data sets that are sensitive to different characteristics such as mineralogy and surface roughness.

  6. ArrayPipe: a flexible processing pipeline for microarray data

    PubMed Central

    Hokamp, Karsten; Roche, Fiona M.; Acab, Michael; Rousseau, Marc-Etienne; Kuo, Byron; Goode, David; Aeschliman, Dana; Bryan, Jenny; Babiuk, Lorne A.; Hancock, Robert E. W.; Brinkman, Fiona S. L.

    2004-01-01

    A number of microarray analysis software packages exist already; however, none combines the user-friendly features of a web-based interface with potential ability to analyse multiple arrays at once using flexible analysis steps. The ArrayPipe web server (freely available at www.pathogenomics.ca/arraypipe) allows the automated application of complex analyses to microarray data which can range from single slides to large data sets including replicates and dye-swaps. It handles output from most commonly used quantification software packages for dual-labelled arrays. Application features range from quality assessment of slides through various data visualizations to multi-step analyses including normalization, detection of differentially expressed genes, andcomparison and highlighting of gene lists. A highly customizable action set-up facilitates unrestricted arrangement of functions, which can be stored as action profiles. A unique combination of web-based and command-line functionality enables comfortable configuration of processes that can be repeatedly applied to large data sets in high throughput. The output consists of reports formatted as standard web pages and tab-delimited lists of calculated values that can be inserted into other analysis programs. Additional features, such as web-based spreadsheet functionality, auto-parallelization and password protection make this a powerful tool in microarray research for individuals and large groups alike. PMID:15215429

  7. Investigation of certain characteristics of thinned antenna arrays with digital signal processing

    NASA Astrophysics Data System (ADS)

    Danilevskii, L. V.; Domanov, Iu. A.; Korobko, O. V.; Tauroginskii, B. I.

    1983-11-01

    A thinned array with correlation processing of input signals is examined. It is shown that amplitude quantization does not change the signal at the thinned-array input as compared with the complete antenna array. The discreteness of time delay causes the thinned and complete arrays to become nonequivalent. Computer-simulation results are presented.

  8. Irma multisensor predictive signature model

    NASA Astrophysics Data System (ADS)

    Watson, John S.; Flynn, David S.; Wellfare, Michael R.; Richards, Mike; Prestwood, Lee

    1995-06-01

    The Irma synthetic signature model was one of the first high resolution synthetic infrared (IR) target and background signature models to be developed for tactical air-to-surface weapon scenarios. Originally developed in 1980 by the Armament Directorate of the Air Force Wright Laboratory (WL/MN), the Irma model was used exclusively to generate IR scenes for smart weapons research and development. In 1988, a number of significant upgrades to Irma were initiated including the addition of a laser channel. This two channel version, Irma 3.0, was released to the user community in 1990. In 1992, an improved scene generator was incorporated into the Irma model which supported correlated frame-to-frame imagery. This and other improvements were released in Irma 2.2. Recently, Irma 3.2, a passive IR/millimeter wave (MMW) code, was completed. Currently, upgrades are underway to include an active MMW channel. Designated Irma 4.0, this code will serve as a cornerstone of sensor fusion research in the laboratory from 6.1 concept development to 6.3 technology demonstration programs for precision guided munitions. Several significant milestones have been reached in this development process and are demonstrated. The Irma 4.0 software design has been developed and interim results are available. Irma is being developed to facilitate multi-sensor smart weapons research and development. It is currently in distribution to over 80 agencies within the U.S. Air Force, U.S. Army, U.S. Navy, ARPA, NASA, Department of Transportation, academia, and industry.

  9. SAR processing with stepped chirps and phased array antennas.

    SciTech Connect

    Doerry, Armin Walter

    2006-09-01

    Wideband radar signals are problematic for phased array antennas. Wideband radar signals can be generated from series or groups of narrow-band signals centered at different frequencies. An equivalent wideband LFM chirp can be assembled from lesser-bandwidth chirp segments in the data processing. The chirp segments can be transmitted as separate narrow-band pulses, each with their own steering phase operation. This overcomes the problematic dilemma of steering wideband chirps with phase shifters alone, that is, without true time-delay elements.

  10. Array Processing in the Cloud: the rasdaman Approach

    NASA Astrophysics Data System (ADS)

    Merticariu, Vlad; Dumitru, Alex

    2015-04-01

    The multi-dimensional array data model is gaining more and more attention when dealing with Big Data challenges in a variety of domains such as climate simulations, geographic information systems, medical imaging or astronomical observations. Solutions provided by classical Big Data tools such as Key-Value Stores and MapReduce, as well as traditional relational databases, proved to be limited in domains associated with multi-dimensional data. This problem has been addressed by the field of array databases, in which systems provide database services for raster data, without imposing limitations on the number of dimensions that a dataset can have. Examples of datasets commonly handled by array databases include 1-dimensional sensor data, 2-D satellite imagery, 3-D x/y/t image time series as well as x/y/z geophysical voxel data, and 4-D x/y/z/t weather data. And this can grow as large as simulations of the whole universe when it comes to astrophysics. rasdaman is a well established array database, which implements many optimizations for dealing with large data volumes and operation complexity. Among those, the latest one is intra-query parallelization support: a network of machines collaborate for answering a single array database query, by dividing it into independent sub-queries sent to different servers. This enables massive processing speed-ups, which promise solutions to research challenges on multi-Petabyte data cubes. There are several correlated factors which influence the speedup that intra-query parallelisation brings: the number of servers, the capabilities of each server, the quality of the network, the availability of the data to the server that needs it in order to compute the result and many more. In the effort of adapting the engine to cloud processing patterns, two main components have been identified: one that handles communication and gathers information about the arrays sitting on every server, and a processing unit responsible with dividing work

  11. Multi-sensor electrometer

    NASA Technical Reports Server (NTRS)

    Gompf, Raymond (Inventor); Buehler, Martin C. (Inventor)

    2003-01-01

    An array of triboelectric sensors is used for testing the electrostatic properties of a remote environment. The sensors may be mounted in the heel of a robot arm scoop. To determine the triboelectric properties of a planet surface, the robot arm scoop may be rubbed on the soil of the planet and the triboelectrically developed charge measured. By having an array of sensors, different insulating materials may be measured simultaneously. The insulating materials may be selected so their triboelectric properties cover a desired range. By mounting the sensor on a robot arm scoop, the measurements can be obtained during an unmanned mission.

  12. Observer-based beamforming algorithm for acoustic array signal processing.

    PubMed

    Bai, Long; Huang, Xun

    2011-12-01

    In the field of noise identification with microphone arrays, conventional delay-and-sum (DAS) beamforming is the most popular signal processing technique. However, acoustic imaging results that are generated by DAS beamforming are easily influenced by background noise, particularly for in situ wind tunnel tests. Even when arithmetic averaging is used to statistically remove the interference from the background noise, the results are far from perfect because the interference from the coherent background noise is still present. In addition, DAS beamforming based on arithmetic averaging fails to deliver real-time computational capability. An observer-based approach is introduced in this paper. This so-called observer-based beamforming method has a recursive form similar to the state observer in classical control theory, thus holds a real-time computational capability. In addition, coherent background noise can be gradually rejected in iterations. Theoretical derivations of the observer-based beamforming algorithm are carefully developed in this paper. Two numerical simulations demonstrate the good coherent background noise rejection and real-time computational capability of the observer-based beamforming, which therefore can be regarded as an attractive algorithm for acoustic array signal processing.

  13. Phased array ultrasonic processing for enhanced and affordable diagnosis

    NASA Astrophysics Data System (ADS)

    Dominguez, N.; Rougeron, G.; Leberre, S.; Pautel, R.

    2013-01-01

    Phased array ultrasonic reconstruction techniques are often presented as a prospect for better and enhanced diagnosis. However to date few applications of these techniques can be found in the industry, partly because of questions on sizing but also because they often require heavy acquisitions. A way forward is then to propose techniques requiring less intensive data acquisition to make them broadly affordable in practice. Several approaches ranging from full matrix capture to paintbrush acquisitions are presented in this paper in combination with associated reconstruction processing like the Total Focusing Method (TFM) and the Time Domain Topological Energy (TDTE) techniques. Emphasis is given to their relative relevancies and practical applicability on typical configurations of interest for industries. The paper also presents recent efforts made on the acceleration of processing computation times, in particular through the use of GPU architectures.

  14. Array Signal Processing for Source Localization and Digital Communication.

    NASA Astrophysics Data System (ADS)

    Song, Bong-Gee

    Array antennas are used in several areas such as sonar and digital communication. Although array patterns may be different depending on applications, they are used with a view to collecting more data and obtaining better results. We first consider a passive sonar system in random environments where the index of refraction is random. While source localization problems for deterministic environments are well studied, they require accurate propagation models which are not available in random environments. We extend the localization problems to random environments. It has been shown that methods developed for deterministic environments fail in random environments because of the stochastic nature of acoustic propagation. Therefore, we model observations as random, and use a statistical signal processing technique combined with physics. The statistical signal model is provided by physics either empirically or theoretically. The performance technique relies on the accuracy of the statistical models. We have applied the maximum likelihood method to angle of arrival estimation and range estimation problems. The Cramer-Rao lower bounds have been also derived to predict the estimation performance. Next, we use the array antennas for diversity combining equalization in digital communications. Spatial diversity equalization is used in two ways; to improve bit error rate or to improve the transmission rate. This is feasible by using more antennas at the receiver end. We apply Helstrom's saddle point integration method to multi -input multi-output communication systems and show that a factor of 3-4 of channel reuse is possible. It is also shown that the advantage is because of the diversity itself not because of more taps. We further improve the equalization performance by joint pre- and postfilter design. Two different methods have been proposed according to the prefilter type. Although the mean square error is not easy to minimize, appropriate methods have been adopted and show

  15. The Use of a Microcomputer Based Array Processor for Real Time Laser Velocimeter Data Processing

    NASA Technical Reports Server (NTRS)

    Meyers, James F.

    1990-01-01

    The application of an array processor to laser velocimeter data processing is presented. The hardware is described along with the method of parallel programming required by the array processor. A portion of the data processing program is described in detail. The increase in computational speed of a microcomputer equipped with an array processor is illustrated by comparative testing with a minicomputer.

  16. Inspecting Composite Ceramic Armor Using Advanced Signal Processing Together with Phased Array Ultrasound

    DTIC Science & Technology

    2010-01-08

    processing techniques have been developed to help improve phased array ultrasonic inspection and analysis of multi-layered ceramic armor panels. The...INSPECTING COMPOSITE CERAMIC ARMOR USING ADVANCED SIGNAL PROCESSING TOGETHER WITH PHASED ARRAY ULTRASOUND J. S. Steckenrider Illinois College...immersion phased array ultrasound system. Some of these specimens had intentional design defects inserted interior to the specimens. Because of the very

  17. Sigma Delta Signal Processing on Via-Configurable Arrays

    DTIC Science & Technology

    2016-03-31

    effective approach for developing circuits like Ms and provide application examples using these techniques. Keywords: Field Programmable Analog Array...Mask Programmable Analog Array; Mixed-Signal ASIC; Sigma Delta Modulation; Structured Array; Switched Capacitor Circuits ; Via-Configurable Array...connects the required analog and digital cells to implement a mixed-signal circuit . Unlike FPGAs, VCAs contain analog cells allowing for integration of

  18. Analysis of Wide-Band Signals Using Wavelet Array Processing

    NASA Astrophysics Data System (ADS)

    Nisii, V.; Saccorotti, G.

    2005-12-01

    Wavelets transforms allow for precise time-frequency localization in the analysis of non-stationary signals. In wavelet analysis the trade-off between frequency bandwidth and time duration, also known as Heisenberg inequality, is by-passed using a fully scalable modulated window which solves the signal-cutting problem of Windowed Fourier Transform. We propose a new seismic array data processing procedure capable of displaying the localized spatial coherence of the signal in both the time- and frequency-domain, in turn deriving the propagation parameters of the most coherent signals crossing the array. The procedure consists in: a) Wavelet coherence analysis for each station pair of the instruments array, aimed at retrieving the frequency- and time-localisation of coherent signals. To this purpose, we use the normalised wavelet cross- power spectrum, smoothed along the time and scale domains. We calculate different coherence spectra adopting smoothing windows of increasing lengths; a final, robust estimate of the time-frequency localisation of spatially-coherent signals is eventually retrieved from the stack of the individual coherence distribution. This step allows for a quick and reliable signal discrimination: wave groups propagating across the network will manifest as high-coherence patches spanning the corresponding time-scale region. b) Once the signals have been localised in the time and frequency domain,their propagation parameters are estimated using a modified MUSIC (MUltiple SIgnal Characterization) algorithm. We select the MUSIC approach as it demonstrated superior performances in the case of low SNR signals, more plane waves contemporaneously impinging at the array and closely separated sources. The narrow-band Coherent Signal Subspace technique is applied to the complex Continuous Wavelet Transform of multichannel data for improving the singularity of the estimated cross-covariance matrix and the accuracy of the estimated signal eigenvectors. Using

  19. Error analysis of subaperture processing in 1-D ultrasound arrays.

    PubMed

    Zhao, Kang-Qiao; Bjåstad, Tore Gruner; Kristoffersen, Kjell

    2015-04-01

    To simplify the medical ultrasound system and reduce the cost, several techniques have been proposed to reduce the interconnections between the ultrasound probe and the back-end console. Among them, subaperture processing (SAP) is the most straightforward approach and is widely used in commercial products. This paper reviews the most important error sources of SAP, such as static focusing, delay quantization, linear delay profile, and coarse apodization, and the impacts introduced by these errors are shown. We propose to use main lobe coherence loss as a simple classification of the quality of the beam profile for a given design. This figure-ofmerit (FoM) is evaluated by simulations with a 1-D ultrasound subaperture array setup. The analytical expressions and the coherence loss can work as a quick guideline in subaperture design by equalizing the merit degradations from different error sources, as well as minimizing the average or maximum loss over ranges. For the evaluated 1-D array example, a good balance between errors and cost was achieved using a subaperture size of 5 elements, focus at 40 mm range, and a delay quantization step corresponding to a phase of π/4.

  20. Multisensor smart system on a chip.

    PubMed

    Sellami, Louiza; Newcomb, Robert W

    2010-01-01

    Sensors are becoming of considerable importance in several areas, particularly in health care. Therefore, the development of inexpensive and miniaturized sensors that are highly selective and sensitive, and for which control and analysis is present all on one chip is very desirable. These types of sensors can be implemented with microelectromechanical systems (MEMS), and because they are fabricated on a semiconductor substrate, additional signal processing circuitry can easily be integrated into the chip, thereby readily providing additional functions, such as multiplexing and analog-to-digital conversion. Here, we present a general framework for the design of a multisensor system on a chip, which includes intelligent signal processing, as well as a built-in self-test and parameter adjustment units. Specifically, we outline the system architecture and develop a transistorized bridge biosensor for monitoring changes in the dielectric constant of a fluid, which could be used for in-home monitoring of kidney function of patients with renal failure.

  1. Automated multisensor registration - Requirements and techniques

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J. M.; Kowk, Ronald; Curlander, John C.; Pang, Shirley S.

    1991-01-01

    The synergistic utilization of data from a suite of remote sensors requires multi-dimensional analysis of the data. Prior to this analysis, processing is required to correct for the systematic geometric distortions characteristic of each sensor, followed by a registration operation to remove any residual offsets. Furthermore, to handle a large volume of data and high data rates, the registration process must be fully automated. A conceptual approach is presented that integrates a variety of registration techniques and selects the candidate algorithm based on certain performance criteria. The performance requirements for an operational algorithm are formulated given the spatially, temporally, and spectrally varying factors that influence the image characteristics and the science requirements of various applications. Several computational techniques are tested and their performance evaluated using a multisensor test data set assembled from the Landsat TM, Seasat, SIR-B, TIMS, and SPOT sensors. The results are discussed and recommendations for future studies are given.

  2. Large-Scale, Multi-Sensor Atmospheric Data Fusion Using Hybrid Cloud Computing

    NASA Astrophysics Data System (ADS)

    Wilson, Brian; Manipon, Gerald; Hua, Hook; Fetzer, Eric

    2014-05-01

    NASA's Earth Observing System (EOS) is an ambitious facility for studying global climate change. The mandate now is to combine measurements from the instruments on the "A-Train" platforms (AIRS, AMSR-E, MODIS, MISR, MLS, and CloudSat) and other Earth probes to enable large-scale studies of climate change over decades. Moving to multi-sensor, long-duration analyses of important climate variables presents serious challenges for large-scale data mining and fusion. For example, one might want to compare temperature and water vapor retrievals from one instrument (AIRS) to another (MODIS), and to a model (ECMWF), stratify the comparisons using a classification of the "cloud scenes" from CloudSat, and repeat the entire analysis over 10 years of data. To efficiently assemble such datasets, we are utilizing Elastic Computing in the Cloud and parallel map-reduce-based algorithms. However, these problems are Data Intensive computing so the data transfer times and storage costs (for caching) are key issues. SciReduce is a Hadoop-like parallel analysis system, programmed in parallel python, that is designed from the ground up for Earth science. SciReduce executes inside VMWare images and scales to any number of nodes in a hybrid Cloud (private eucalyptus & public Amazon). Unlike Hadoop, SciReduce operates on bundles of named numeric arrays, which can be passed in memory or serialized to disk in netCDF4 or HDF5. Multi-year datasets are automatically "sharded" by time and space across a cluster of nodes so that years of data (millions of files) can be processed in a massively parallel way. Input variables (arrays) are pulled on-demand into the Cloud using OPeNDAP URLs or other subsetting services, thereby minimizing the size of the cached input and intermediate datasets. We are using SciReduce to automate the production of multiple versions of a ten-year A-Train water vapor climatology under a NASA MEASURES grant. We will present the architecture of SciReduce, describe the

  3. An operational approach for infrasound multi-array processing

    NASA Astrophysics Data System (ADS)

    Vergoz, J.; Le Pichon, A.; Herry, P.; Blanc, E.

    2009-04-01

    The infrasound network of the International Monitoring Network (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is currently not fully established. However, it has demonstrated its capability for detecting and locating infrasonic sources like meteorites as well as volcanic eruptions on a global scale. Unfortunately, such ground truth events are rare. Therefore, regions with dense infrasound networks have to be considered in order to test and calibrate detection and location procedures (Le Pichon. et al. 2008, J. Geophys. Res., 113, D12115, doi:10.1029/2007JD009509). In Central Europe, several years of continuous infrasound recordings are available for many infrasound arrays, where not all of them are part of the IMS. Infrasound waveforms are routinely processed in the 0.1 to 4 Hz frequency band using PMCC as a real-time detector. After applying a categorization procedure to remove detections associated with environmental noise, a blind fusion provides a list of events to be reviewed by the analyst. In order to check the geophysical consistency of the located events, an interactive tool has been developed. All results of the automatic processing are presented along with a realistic estimate of the network detection capability which incorporates near-real time atmospheric updates. Among the dominant acoustic sources of human origin, peaks in the geographical distribution of infrasound events correspond well with seismically active regions where operational mines have been identified. With the increasing number of IMS and regional cluster infrasound arrays deployed around the globe, conducting consistent analyses on a routine-basis provides an extensive database for discriminating between natural and artificial acoustic sources. Continuing such studies may also help quantifying relationships between infrasonic observables and atmospheric specification problems, thus opening new fields for investigations into inverse problems.

  4. Smart-Pixel Array Processors Based on Optimal Cellular Neural Networks for Space Sensor Applications

    NASA Technical Reports Server (NTRS)

    Fang, Wai-Chi; Sheu, Bing J.; Venus, Holger; Sandau, Rainer

    1997-01-01

    A smart-pixel cellular neural network (CNN) with hardware annealing capability, digitally programmable synaptic weights, and multisensor parallel interface has been under development for advanced space sensor applications. The smart-pixel CNN architecture is a programmable multi-dimensional array of optoelectronic neurons which are locally connected with their local neurons and associated active-pixel sensors. Integration of the neuroprocessor in each processor node of a scalable multiprocessor system offers orders-of-magnitude computing performance enhancements for on-board real-time intelligent multisensor processing and control tasks of advanced small satellites. The smart-pixel CNN operation theory, architecture, design and implementation, and system applications are investigated in detail. The VLSI (Very Large Scale Integration) implementation feasibility was illustrated by a prototype smart-pixel 5x5 neuroprocessor array chip of active dimensions 1380 micron x 746 micron in a 2-micron CMOS technology.

  5. Smart-Pixel Array Processors Based on Optimal Cellular Neural Networks for Space Sensor Applications

    NASA Technical Reports Server (NTRS)

    Fang, Wai-Chi; Sheu, Bing J.; Venus, Holger; Sandau, Rainer

    1997-01-01

    A smart-pixel cellular neural network (CNN) with hardware annealing capability, digitally programmable synaptic weights, and multisensor parallel interface has been under development for advanced space sensor applications. The smart-pixel CNN architecture is a programmable multi-dimensional array of optoelectronic neurons which are locally connected with their local neurons and associated active-pixel sensors. Integration of the neuroprocessor in each processor node of a scalable multiprocessor system offers orders-of-magnitude computing performance enhancements for on-board real-time intelligent multisensor processing and control tasks of advanced small satellites. The smart-pixel CNN operation theory, architecture, design and implementation, and system applications are investigated in detail. The VLSI (Very Large Scale Integration) implementation feasibility was illustrated by a prototype smart-pixel 5x5 neuroprocessor array chip of active dimensions 1380 micron x 746 micron in a 2-micron CMOS technology.

  6. Coherent Optical Processing of Phased Array Radar Data

    NASA Technical Reports Server (NTRS)

    Rogers, J. W.

    1972-01-01

    Interfacing a coherent optical processor, which utilizes an electron-beam addressed, potassium dideuterium phosphate (KDP) crystal modulator, with a linear phased array is studied. An abbreviated development of typical radar signals from a linear array is included. A plan for formating the spatial modulator with linear array signals is presented. The theoretical expectations which include target angle and Doppler are derived. A simulated set of M signals which are typical of a linear array of M elements was devised. This set of signals was used to modulate the wave front of collimated laser light via the KDP crystal according to the format presented.

  7. Adaptive beamforming for array signal processing in aeroacoustic measurements.

    PubMed

    Huang, Xun; Bai, Long; Vinogradov, Igor; Peers, Edward

    2012-03-01

    Phased microphone arrays have become an important tool in the localization of noise sources for aeroacoustic applications. In most practical aerospace cases the conventional beamforming algorithm of the delay-and-sum type has been adopted. Conventional beamforming cannot take advantage of knowledge of the noise field, and thus has poorer resolution in the presence of noise and interference. Adaptive beamforming has been used for more than three decades to address these issues and has already achieved various degrees of success in areas of communication and sonar. In this work an adaptive beamforming algorithm designed specifically for aeroacoustic applications is discussed and applied to practical experimental data. It shows that the adaptive beamforming method could save significant amounts of post-processing time for a deconvolution method. For example, the adaptive beamforming method is able to reduce the DAMAS computation time by at least 60% for the practical case considered in this work. Therefore, adaptive beamforming can be considered as a promising signal processing method for aeroacoustic measurements.

  8. Fault detection and exclusion in multisensor navigation systems

    NASA Technical Reports Server (NTRS)

    Bernath, Gregory N.

    1995-01-01

    In order for a multisensor navigation system to meet integrity requirements, there must be a way of detecting erroneous measurements, using only data from those measurements. This can be accomplished using a parity space estimation algorithm. Erroneous measurements must then be removed from the position solution; the entire process is called fault detection and exclusion (FDE). A baseline FDE algorithm has been determined, and is capable of working in real time on present affordable hardware.

  9. Analysis of Eigenspace Dynamics with Applications to Array Processing

    DTIC Science & Technology

    2014-09-30

    drifting arrays strongly affected by deformation or array-depth perturbations. The long-term goal of this effort is the development of physically...J., “Measurements of three-dimensional propagation in a continental shelf environment”, J. Acoust. Soc. Am. 125, pp. 1394-1402, 2009

  10. Damage Detection in Composite Structures with Wavenumber Array Data Processing

    NASA Technical Reports Server (NTRS)

    Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

    2013-01-01

    Guided ultrasonic waves (GUW) have the potential to be an efficient and cost-effective method for rapid damage detection and quantification of large structures. Attractive features include sensitivity to a variety of damage types and the capability of traveling relatively long distances. They have proven to be an efficient approach for crack detection and localization in isotropic materials. However, techniques must be pushed beyond isotropic materials in order to be valid for composite aircraft components. This paper presents our study on GUW propagation and interaction with delamination damage in composite structures using wavenumber array data processing, together with advanced wave propagation simulations. Parallel elastodynamic finite integration technique (EFIT) is used for the example simulations. Multi-dimensional Fourier transform is used to convert time-space wavefield data into frequency-wavenumber domain. Wave propagation in the wavenumber-frequency domain shows clear distinction among the guided wave modes that are present. This allows for extracting a guided wave mode through filtering and reconstruction techniques. Presence of delamination causes spectral change accordingly. Results from 3D CFRP guided wave simulations with delamination damage in flat-plate specimens are used for wave interaction with structural defect study.

  11. Damage Detection in Composite Structures with Wavenumber Array Data Processing

    NASA Technical Reports Server (NTRS)

    Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

    2013-01-01

    Guided ultrasonic waves (GUW) have the potential to be an efficient and cost-effective method for rapid damage detection and quantification of large structures. Attractive features include sensitivity to a variety of damage types and the capability of traveling relatively long distances. They have proven to be an efficient approach for crack detection and localization in isotropic materials. However, techniques must be pushed beyond isotropic materials in order to be valid for composite aircraft components. This paper presents our study on GUW propagation and interaction with delamination damage in composite structures using wavenumber array data processing, together with advanced wave propagation simulations. Parallel elastodynamic finite integration technique (EFIT) is used for the example simulations. Multi-dimensional Fourier transform is used to convert time-space wavefield data into frequency-wavenumber domain. Wave propagation in the wavenumber-frequency domain shows clear distinction among the guided wave modes that are present. This allows for extracting a guided wave mode through filtering and reconstruction techniques. Presence of delamination causes spectral change accordingly. Results from 3D CFRP guided wave simulations with delamination damage in flat-plate specimens are used for wave interaction with structural defect study.

  12. SVD Approaches in Multisource, Multipath Passive Array Processing.

    NASA Astrophysics Data System (ADS)

    Lo, Chien-Kuo

    Several system identification techniques have been proposed to treat high resolution directional finding problems in passive sonar, radar, and communication systems. In this dissertation, we present a new covariance approximation approach. The covariance matrices of source signals, in stationary environments often have a special form known as Toeplitz matrix. Our approach is based on what is known as the Toeplitz approximation method (TAM) via Singular Value Decomposition (SVD) in stochastic realization theory, which can deal with the color noise environment and the correlated sources. One of such practical situations is the multipath situation. To reduce the effect of rounding errors incurred in spectrum estimation algorithm, a SVD state space modeling is suggested. It offers the important advantage of low sensitivity to the perturbation of parameter estimation. Using the TAM approach we can first obtain source bearing information, and then cancel undesired signals. For cancellation, we introduce a Least-Square beamformer to form an adaptive spatial filter network. The weighting vector of our spatial filter is derived using a Gram-Schmidt partial orthogonalization procedure which leads to an adaptive scheme, allowing computational savings. This recursive algorithm enjoys another important feature in that it may be implemented in a compact VLSI array processor, such as wavefront/systolic array processors. This implementation aspect is critical for real-time processing applications. Another problem discussed in the dissertation is that of determining desired or undesired path directions from target source under the hypothesis of given correlation coefficients. For that we first formulate the path identification criterion. The decision criterion is based upon the probability density function for estimated path correlation coefficients. The performance of such criterion is also discussed. Extensive simulations have been conducted and the simulation results indicate

  13. Model-based Processing of Micro-cantilever Sensor Arrays

    SciTech Connect

    Tringe, J W; Clague, D S; Candy, J V; Lee, C L; Rudd, R E; Burnham, A K

    2004-11-17

    We develop a model-based processor (MBP) for a micro-cantilever array sensor to detect target species in solution. After discussing the generalized framework for this problem, we develop the specific model used in this study. We perform a proof-of-concept experiment, fit the model parameters to the measured data and use them to develop a Gauss-Markov simulation. We then investigate two cases of interest: (1) averaged deflection data, and (2) multi-channel data. In both cases the evaluation proceeds by first performing a model-based parameter estimation to extract the model parameters, next performing a Gauss-Markov simulation, designing the optimal MBP and finally applying it to measured experimental data. The simulation is used to evaluate the performance of the MBP in the multi-channel case and compare it to a ''smoother'' (''averager'') typically used in this application. It was shown that the MBP not only provides a significant gain ({approx} 80dB) in signal-to-noise ratio (SNR), but also consistently outperforms the smoother by 40-60 dB. Finally, we apply the processor to the smoothed experimental data and demonstrate its capability for chemical detection. The MBP performs quite well, though it includes a correctable systematic bias error. The project's primary accomplishment was the successful application of model-based processing to signals from micro-cantilever arrays: 40-60 dB improvement vs. the smoother algorithm was demonstrated. This result was achieved through the development of appropriate mathematical descriptions for the chemical and mechanical phenomena, and incorporation of these descriptions directly into the model-based signal processor. A significant challenge was the development of the framework which would maximize the usefulness of the signal processing algorithms while ensuring the accuracy of the mathematical description of the chemical-mechanical signal. Experimentally, the difficulty was to identify and characterize the non

  14. A bit-serial VLSI array processing chip for image processing

    NASA Technical Reports Server (NTRS)

    Heaton, Robert; Blevins, Donald; Davis, Edward

    1990-01-01

    An array processing chip integrating 128 bit-serial processing elements (PEs) on a single die is discussed. Each PE has a 16-function logic unit, a single-bit adder, a 32-b variable-length shift register, and 1 kb of local RAM. Logic in each PE provides the capability to mask PEs individually. A modified grid interconnection scheme allows each PE to communicate with each of its eight nearest neighbors. A 32-b bus is used to transfer data to and from the array in a single cycle. Instruction execution is pipelined, enabling all instructions to be executed in a single cycle. The 1-micron CMOS design contains over 1.1 x 10 to the 6th transistors on an 11.0 x 11.7-mm die.

  15. A bit-serial VLSI array processing chip for image processing

    NASA Technical Reports Server (NTRS)

    Heaton, Robert; Blevins, Donald; Davis, Edward

    1990-01-01

    An array processing chip integrating 128 bit-serial processing elements (PEs) on a single die is discussed. Each PE has a 16-function logic unit, a single-bit adder, a 32-b variable-length shift register, and 1 kb of local RAM. Logic in each PE provides the capability to mask PEs individually. A modified grid interconnection scheme allows each PE to communicate with each of its eight nearest neighbors. A 32-b bus is used to transfer data to and from the array in a single cycle. Instruction execution is pipelined, enabling all instructions to be executed in a single cycle. The 1-micron CMOS design contains over 1.1 x 10 to the 6th transistors on an 11.0 x 11.7-mm die.

  16. Signal processing techniques applied to a small circular seismic array

    NASA Astrophysics Data System (ADS)

    Mosher, C. C.

    1980-03-01

    The travel time method (TTM) for locating earthquakes and the wavefront curvature method (WCM), which determines distance to an event by measuring the curvature of the wavefront can be combined in a procedure referred to as Apparent Velocity Mapping (AVM). Apparent velocities for mine blasts and local earthquakes computed by the WCM are inverted for a velocity structure. The velocity structure is used in the TTM to relocate events. Model studies indicate that AVM can adequately resolve the velocity structure for the case of linear velocity-depth gradient. Surface waves from mine blasts recorded by the Central Minnesota Seismic Array were analyzed using a modification of the multiple filter analysis (MFA) technique to determine group arrival times at several stations of an array. The advantages of array MFA are that source location need not be known, lateral refraction can be detected and removed, and multiple arrivals can be separated. A modeling procedure that can be used with array MFA is described.

  17. Large-Scale, Multi-Sensor Atmospheric Data Fusion Using Hybrid Cloud Computing

    NASA Astrophysics Data System (ADS)

    Wilson, B. D.; Manipon, G.; Hua, H.; Fetzer, E. J.

    2015-12-01

    NASA's Earth Observing System (EOS) is an ambitious facility for studying global climate change. The mandate now is to combine measurements from the instruments on the "A-Train" platforms (AIRS, MODIS, MLS, and CloudSat) and other Earth probes to enable large-scale studies of climate change over decades. Moving to multi-sensor, long-duration presents serious challenges for large-scale data mining and fusion. For example, one might want to compare temperature and water vapor retrievals from one instrument (AIRS) to another (MODIS), and to a model (ECMWF), stratify the comparisons using a classification of the "cloud scenes" from CloudSat, and repeat the entire analysis over 10 years of data. HySDS is a Hybrid-Cloud Science Data System that has been developed and applied under NASA AIST, MEaSUREs, and ACCESS grants. HySDS uses the SciFlow workflow engine to partition analysis workflows into parallel tasks (e.g. segmenting by time or space) that are pushed into a durable job queue. The tasks are "pulled" from the queue by worker Virtual Machines (VM's) and executed in an on-premise Cloud (Eucalyptus or OpenStack) or at Amazon in the public Cloud or govCloud. In this way, years of data (millions of files) can be processed in a massively parallel way. Input variables (arrays) are pulled on-demand into the Cloud using OPeNDAP URLs or other subsetting services, thereby minimizing the size of the transferred data. We are using HySDS to automate the production of multiple versions of a ten-year A-Train water vapor climatology under a MEASURES grant. We will present the architecture of HySDS, describe the achieved "clock time" speedups in fusing datasets on our own nodes and in the Amazon Cloud, and discuss the Cloud cost tradeoffs for storage, compute, and data transfer. Our system demonstrates how one can pull A-Train variables (Levels 2 & 3) on-demand into the Amazon Cloud, and cache only those variables that are heavily used, so that any number of compute jobs can be

  18. Expanding Coherent Array Processing to Larger Apertures Using Empirical Matched Field Processing

    SciTech Connect

    Ringdal, F; Harris, D B; Kvaerna, T; Gibbons, S J

    2009-07-23

    We have adapted matched field processing, a method developed in underwater acoustics to detect and locate targets, to classify transient seismic signals arising from mining explosions. Matched field processing, as we apply it, is an empirical technique, using observations of historic events to calibrate the amplitude and phase structure of wavefields incident upon an array aperture for particular repeating sources. The objective of this project is to determine how broadly applicable the method is and to understand the phenomena that control its performance. We obtained our original results in distinguishing events from ten mines in the Khibiny and Olenegorsk mining districts of the Kola Peninsula, for which we had exceptional ground truth information. In a cross-validation test, some 98.2% of 549 explosions were correctly classified by originating mine using just the Pn observations (2.5-12.5 Hz) on the ARCES array at ranges from 350-410 kilometers. These results were achieved despite the fact that the mines are as closely spaced as 3 kilometers. Such classification performance is significantly better than predicted by the Rayleigh limit. Scattering phenomena account for the increased resolution, as we make clear in an analysis of the information carrying capacity of Pn under two alternative propagation scenarios: free-space propagation and propagation with realistic (actually measured) spatial covariance structure. The increase in information capacity over a wide band is captured by the matched field calibrations and used to separate explosions from very closely-spaced sources. In part, the improvement occurs because the calibrations enable coherent processing at frequencies above those normally considered coherent. We are investigating whether similar results can be expected in different regions, with apertures of increasing scale and for diffuse seismicity. We verified similar performance with the closely-spaced Zapolyarni mines, though discovered that it may be

  19. Two subroutines used in processing of arrayed data files

    NASA Astrophysics Data System (ADS)

    Wu, Guang-Jie

    Arrayed data files are commonly used in astronomy. It may be a text file compiled by the software "EDIT" in common use, or a table compiled by Microsoft WORD, Excel, or a FITS format etc. In the database of CDS (Centre de Données astronomiques de Strasbourg), there are over thousands star catalogues. Sometimes you may get a star catalogue from a colleague or friend of you, which may be done by multivarious computer software and may have peculiarity of sorts. Especially, the star catalogue had been compiled several years ago. You may often need to deal with such listed multidimensional data files, and you may need to make new listed data files by yourself. This processing for reduce-dimension or add-dimension, if it was a kind of row treatment, is very easy to do with some famous software like "EDIT". However, maybe you are facing a column treatment. It may bring some trouble to you. In some cases, a character "Tab" may exist in the file. Different software, even different printers made by a certain company, may give dissimilar treatment to the character "Tab". The problem is that a Table-key can denote a single space-key, or can be up to eight space-keys. Sometimes, it may not be easy to find a ready-made program in your hands. If this data file could be opened by the software "EDIT", two programs in this paper can help you to understand what happened there, and help you to solve the problem conveniently and easily. It includes to convert all of the Table-keys to be corresponding space-keys, to pick-up, delete, add blanks, or link two data files as two columns in one file.

  20. Hierarchical Multisensor Image Understanding.

    DTIC Science & Technology

    1984-07-01

    paradigm based on graphs with attributed lists as nodes and image processing operators as p - arcs . This report reviews activities on the project during...other eight. Four of these proved to require context-based information in order to perform reasonable region discrimination. The remaining four I S... order to achieve a novel, real-time implementation of the conflict resolution rules. Each pixel in each labeled image is labeled "on" if it is part of a

  1. Structure and Process of Infrared Hot Electron Transistor Arrays

    PubMed Central

    Fu, Richard

    2012-01-01

    An infrared hot-electron transistor (IHET) 5 × 8 array with a common base configuration that allows two-terminal readout integration was investigated and fabricated for the first time. The IHET structure provides a maximum factor of six in improvement in the photocurrent to dark current ratio compared to the basic quantum well infrared photodetector (QWIP), and hence it improved the array S/N ratio by the same factor. The study also showed for the first time that there is no electrical cross-talk among individual detectors, even though they share the same emitter and base contacts. Thus, the IHET structure is compatible with existing electronic readout circuits for photoconductors in producing sensitive focal plane arrays. PMID:22778655

  2. Structure and process of infrared hot electron transistor arrays.

    PubMed

    Fu, Richard

    2012-01-01

    An infrared hot-electron transistor (IHET) 5 × 8 array with a common base configuration that allows two-terminal readout integration was investigated and fabricated for the first time. The IHET structure provides a maximum factor of six in improvement in the photocurrent to dark current ratio compared to the basic quantum well infrared photodetector (QWIP), and hence it improved the array S/N ratio by the same factor. The study also showed for the first time that there is no electrical cross-talk among individual detectors, even though they share the same emitter and base contacts. Thus, the IHET structure is compatible with existing electronic readout circuits for photoconductors in producing sensitive focal plane arrays.

  3. Adventures in Creating an Historical Multi-sensor Precipitation Dataset

    NASA Astrophysics Data System (ADS)

    Fuelberg, H. E.

    2008-05-01

    Florida State University has created a ten year historical multi-sensor precipitation dataset using the National Weather Service's (NWS) Multi-sensor Precipitation Estimator (MPE) software. MPE combines the high spatial resolution of radar-derived estimates with the assumed "ground truth" of the gauges. Input for the procedure included radar-derived hourly digital precipitation arrays on the 4 x 4 km HRAP grid, together with hourly rain gauge data from the National Climatic Data Center and five Florida Water Management Districts. This combination of gauge information provides comparatively high spatial resolution. The MPE output consists of hourly rainfall estimates on the 4 x 4 km grid. This paper will describe the many challenges that we faced in creating the multi-sensor data set. Some of the topics to be discussed are 1) Rain gauge data, even if said to have been quality controlled, still need a careful additional check. Objective procedures are needed due to the vast amount of hourly data, and it is challenging to develop a scheme that will catch most errors without deleting valid information. 2) The radar data also require careful scrutiny. Many types of false or erroneous returns lurk within the files and can lead to erroneous multi- sensor results. 3) The MPE procedure contains many adaptable parameters that need to be tuned to account for density of the available data and the character of the precipitation. These parameters generally will need to be changed based on the geographical area of study. Finally, examples of the MPE dataset will be shown along with brief comparisons with gauge data alone.

  4. Multisensor user authentication

    NASA Astrophysics Data System (ADS)

    Colombi, John M.; Krepp, D.; Rogers, Steven K.; Ruck, Dennis W.; Oxley, Mark E.

    1993-09-01

    User recognition is examined using neural and conventional techniques for processing speech and face images. This article for the first time attempts to overcome this significant problem of distortions inherently captured over multiple sessions (days). Speaker recognition uses both Linear Predictive Coding (LPC) cepstral and auditory neural model representations with speaker dependent codebook designs. For facial imagery, recognition is developed on a neural network that consists of a single hidden layer multilayer perceptron backpropagation network using either the raw data as inputs or principal components of the raw data computed using the Karhunen-Loeve Transform as inputs. The data consists of 10 subjects; each subject recorded utterances and had images collected for 10 days. The utterances collected were 400 rich phonetic sentences (4 sec), 200 subject name recordings (3 sec), and 100 imposter name recordings (3 sec). Face data consists of over 2000, 32 X 32 pixel, 8 bit gray scale images of the 10 subjects. Each subsystem attains over 90% verification accuracy individually using test data gathered on days following the training data.

  5. Multisensor user authentication

    NASA Astrophysics Data System (ADS)

    Colombi, John M.; Krepp, D.; Rogers, Steven K.; Ruck, Dennis W.; Oxley, Mark E.

    1993-08-01

    User recognition is examined using neural and conventional techniques for processing speech and face images. This article for the first time attempts to overcome this significant problem of distortions inherently captured over multiple sessions (days). Speaker recognition uses both Linear Predictive Coding (LPC) cepstral and auditory neural model representations with speaker dependent codebook designs. For facial imagery, recognition is developed on a neural network that consists of a single hidden layer multilayer perceptron backpropagation network using either the raw data as inputs or principal components of the raw data computed using the Karhunen-Loeve Transform as inputs. The data consists of 10 subjects; each subject recorded utterances and had images collected for 10 days. The utterances collected were 400 rich phonetic sentences (4 sec), 200 subject name recordings (3 sec), and 100 imposter name recordings (3 sec). Face data consists of over 2000, 32 X 32 pixel, 8 bit gray scale images of the 10 subjects. Each subsystem attains over 90% verification accuracy individually using test data gathered on day following the training data.

  6. A novel scalable manufacturing process for the production of hydrogel-forming microneedle arrays

    PubMed Central

    Lutton, Rebecca E.M.; Larrañeta, Eneko; Kearney, Mary-Carmel; Boyd, Peter; Woolfson, A.David; Donnelly, Ryan F.

    2015-01-01

    A novel manufacturing process for fabricating microneedle arrays (MN) has been designed and evaluated. The prototype is able to successfully produce 14 × 14 MN arrays and is easily capable of scale-up, enabling the transition from laboratory to industry and subsequent commercialisation. The method requires the custom design of metal MN master templates to produce silicone MN moulds using an injection moulding process. The MN arrays produced using this novel method was compared with centrifugation, the traditional method of producing aqueous hydrogel-forming MN arrays. The results proved that there was negligible difference between either methods, with each producing MN arrays with comparable quality. Both types of MN arrays can be successfully inserted in a skin simulant. In both cases the insertion depth was approximately 60% of the needle length and the height reduction after insertion was in both cases approximately 3%. PMID:26302858

  7. A novel scalable manufacturing process for the production of hydrogel-forming microneedle arrays.

    PubMed

    Lutton, Rebecca E M; Larrañeta, Eneko; Kearney, Mary-Carmel; Boyd, Peter; Woolfson, A David; Donnelly, Ryan F

    2015-10-15

    A novel manufacturing process for fabricating microneedle arrays (MN) has been designed and evaluated. The prototype is able to successfully produce 14×14 MN arrays and is easily capable of scale-up, enabling the transition from laboratory to industry and subsequent commercialisation. The method requires the custom design of metal MN master templates to produce silicone MN moulds using an injection moulding process. The MN arrays produced using this novel method was compared with centrifugation, the traditional method of producing aqueous hydrogel-forming MN arrays. The results proved that there was negligible difference between either methods, with each producing MN arrays with comparable quality. Both types of MN arrays can be successfully inserted in a skin simulant. In both cases the insertion depth was approximately 60% of the needle length and the height reduction after insertion was in both cases approximately 3%. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Multisensor data fusion algorithm development

    SciTech Connect

    Yocky, D.A.; Chadwick, M.D.; Goudy, S.P.; Johnson, D.K.

    1995-12-01

    This report presents a two-year LDRD research effort into multisensor data fusion. We approached the problem by addressing the available types of data, preprocessing that data, and developing fusion algorithms using that data. The report reflects these three distinct areas. First, the possible data sets for fusion are identified. Second, automated registration techniques for imagery data are analyzed. Third, two fusion techniques are presented. The first fusion algorithm is based on the two-dimensional discrete wavelet transform. Using test images, the wavelet algorithm is compared against intensity modulation and intensity-hue-saturation image fusion algorithms that are available in commercial software. The wavelet approach outperforms the other two fusion techniques by preserving spectral/spatial information more precisely. The wavelet fusion algorithm was also applied to Landsat Thematic Mapper and SPOT panchromatic imagery data. The second algorithm is based on a linear-regression technique. We analyzed the technique using the same Landsat and SPOT data.

  9. Dimpled Ball Grid Array process development for space flight applications

    NASA Technical Reports Server (NTRS)

    Barr, S. L.; Mehta, A.

    2000-01-01

    The 472 Dimpled Ball Grid Array (D-BGA) package has not been used in past space flight environments, therefore it is necessary to determine the robustness and reliability of the solder joints. The 472 D-BGA packages passed the above environmental tests within the specifications and are now qualified for use on space flight electronics.

  10. Micromachined Thermoelectric Sensors and Arrays and Process for Producing

    NASA Technical Reports Server (NTRS)

    Foote, Marc C. (Inventor); Jones, Eric W. (Inventor); Caillat, Thierry (Inventor)

    2000-01-01

    Linear arrays with up to 63 micromachined thermopile infrared detectors on silicon substrates have been constructed and tested. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi-Te and Bi-Sb-Te thermoelectric elements films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4 x 10(exp 9) cmHz(exp 1/2)/W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. The arrays are well suited for uncooled dispersive point spectrometers. In another embodiment, also with Bi-Te and Bi-Sb-Te thermoelectric materials on micromachined silicon nitride membranes, detector arrays have been produced with D* values as high as 2.2 x 10(exp 9) cm Hz(exp 1/2)/W for 83 ms response times.

  11. Evaluation of array-processing algorithms for a headband hearing aid

    NASA Astrophysics Data System (ADS)

    Greenberg, Julie E.; Desloge, Joseph G.; Zurek, Patrick M.

    2003-03-01

    Several array-processing algorithms were implemented and evaluated with experienced hearing-aid users. The array consisted of four directional microphones mounted broadside on a headband worn on the top of the listener's head. The algorithms included two adaptive array-processing algorithms, one fixed array-processing algorithm, and a reference condition consisting of binaural directional microphones. The algorithms were evaluated under conditions with both one and three independent noise sources. Performance metrics included quantitative speech reception thresholds and qualitative subject preference ratings for ease-of-listening measured using a paired-comparison procedure. On average, the fixed algorithm improved speech reception thresholds by 2 dB, while the adaptive algorithms provided 7-9-dB improvement over the reference condition. Subjects judging ease-of-listening generally preferred all array-processing algorithms over the reference condition. The results suggest that these adaptive algorithms should be evaluated further in more realistic acoustic environments.

  12. Orbital Processing of Eutectic Rod-Like Arrays

    NASA Technical Reports Server (NTRS)

    Larson, David J., Jr.

    1998-01-01

    The eutectic is one of only three solidification classes that exist. The others are isostructural and peritectic-class reactions, respectively. Simplistically, in a binaryeutectic phase diagram, a single liquid phase isothermally decomposes to two solid phases in a cooperative manner. The melting point minimum at the eutectic composition, isothermal solidification temperature, near-isocompositional solidification and refined solidification microstructure lend themselves naturally to such applications as brazing and soldering; industries that eutectic alloys dominate. Interest in direct process control of microstructures has led, more recently, to in-situ eutectic directional solidification with applications in electro-magnetics and electro-optics. In these cases, controlled structural refinement and the high aspect ratio and regularity of the distributed eutectic phases is highly significant to the fabrication and application of these in-situ natural composites. The natural pattern formation and scaling of the dispersed phase on a sub-micron scale has enormous potential application, since fabricating bulk materials on this scale mechanically has proven to be particularly difficult. It is thus of obvious importance to understand the solidification of eutectic materials since they are of great commercial significance. The dominant theory that describes eutectic solidification was derived for diffusion-controlled growth of alloys where both solid eutectic phases solidify metallically, i.e. without faceting at the solidification interface. Both high volume fraction (lamellar) and low volume fraction (rod-like) regular metallic arrays are treated by this theory. Many of the useful solders and brazements, however, and most of the regular in-situ composites are characterized by solidification reactions that are faceted/non-faceted in nature, rather than doubly non-faceted (metallic). Further, diffusion-controlled growth conditions are atypical terrestrially since

  13. Body-Attachable and Stretchable Multisensors Integrated with Wirelessly Rechargeable Energy Storage Devices.

    PubMed

    Kim, Daeil; Kim, Doyeon; Lee, Hyunkyu; Jeong, Yu Ra; Lee, Seung-Jung; Yang, Gwangseok; Kim, Hyoungjun; Lee, Geumbee; Jeon, Sanggeun; Zi, Goangseup; Kim, Jihyun; Ha, Jeong Sook

    2016-01-27

    A stretchable multisensor system is successfully demonstrated with an integrated energy-storage device, an array of microsupercapacitors that can be repeatedly charged via a wireless radio-frequency power receiver on the same stretchable polymer substrate. The integrated devices are interconnected by a liquid-metal interconnection and operate stably without noticeable performance degradation under strain due to the skin attachment, and a uniaxial strain up to 50%.

  14. Monitoring of Reinforced Concrete Corrosion and Deterioration by Periodic Multi-Sensor Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

    Arndt, R. W.; Cui, J.; Huston, D. R.

    2011-06-01

    The paper showcases a collaborative benchmark project evaluating NDE methods for deterioration monitoring of laboratory bridge decks. The focus of this effort is to design and build concrete test specimens, artificially induce and monitor corrosion, periodically perform multi-sensor NDE inspections, followed by 3D imaging and destructive validations. NDE methods used include ultrasonic echo array, ground penetrating radar (GPR), active infrared thermography with induction heating, and time-resolved thermography with induction heating.

  15. Imaging and data processing with the Low Frequency Space Array

    NASA Technical Reports Server (NTRS)

    Simon, R. S.; Spencer, J. H.; Dennison, B. K.; Weiler, K. W.; Johnston, K. J.; Kaiser, M. L.; Desch, M. D.; Fainberg, J.; Brown, L. W.; Stone, R. G.

    1987-01-01

    The Low Frequency Space Array (LFSA) is being designed to image the entire sky at extremely low radio frequencies with arcmin to subarcmin resolution. To accomplish this goal, data from LFSA will be continuously integrated for many months and then be used with aperture synthesis techniques to produce images. The three dimensional nature of LFSA and the effects of orbital geometry make LFSA a continuously evolving array which has an excellent synthesized point-response function. After transforming the data to produce an initial image, it is possible to remove low-level sidelobe responses remaining in the image and thereby produce a high dynamic-range image. Interference (both man-made and from solar-system objects) is a potential problem for LFSA, but appropriate data handling techniques are available which should eliminate any of its effects.

  16. Application of Seismic Array Processing to Tsunami Early Warning

    NASA Astrophysics Data System (ADS)

    An, C.; Meng, L.

    2015-12-01

    Tsunami wave predictions of the current tsunami warning systems rely on accurate earthquake source inversions of wave height data. They are of limited effectiveness for the near-field areas since the tsunami waves arrive before data are collected. Recent seismic and tsunami disasters have revealed the need for early warning to protect near-source coastal populations. In this work we developed the basis for a tsunami warning system based on rapid earthquake source characterisation through regional seismic array back-projections. We explored rapid earthquake source imaging using onshore dense seismic arrays located at regional distances on the order of 1000 km, which provides faster source images than conventional teleseismic back-projections. We implement this method in a simulated real-time environment, and analysed the 2011 Tohoku earthquake rupture with two clusters of Hi-net stations in Kyushu and Northern Hokkaido, and the 2014 Iquique event with the Earthscope USArray Transportable Array. The results yield reasonable estimates of rupture area, which is approximated by an ellipse and leads to the construction of simple slip models based on empirical scaling of the rupture area, seismic moment and average slip. The slip model is then used as the input of the tsunami simulation package COMCOT to predict the tsunami waves. In the example of the Tohoku event, the earthquake source model can be acquired within 6 minutes from the start of rupture and the simulation of tsunami waves takes less than 2 min, which could facilitate a timely tsunami warning. The predicted arrival time and wave amplitude reasonably fit observations. Based on this method, we propose to develop an automatic warning mechanism that provides rapid near-field warning for areas of high tsunami risk. The initial focus will be Japan, Pacific Northwest and Alaska, where dense seismic networks with the capability of real-time data telemetry and open data accessibility, such as the Japanese HiNet (>800

  17. Signal processing for damage detection using two different array transducers.

    PubMed

    El Youbi, F; Grondel, S; Assaad, J

    2004-04-01

    This work describes an investigation into the development of a new health monitoring system for aeronautical applications. The health monitoring system is based on the emission and reception of Lamb waves by multi-element piezoelectric transducers (i.e., arrays) bonded to the structure. The emitter array consists of three different elementary bar transducers. These transducers have the same thickness and length but different widths. The receiver array has 32 same elements. This system offers the possibility to understand the nature of the generated waves and to determine the sensitivity of each mode to possible damage. It presents two principal advantages: Firstly, by exciting all elements in phase, it is possible to generate several Lamb modes in the same time. Secondly, the two-dimensional fourier transform (2D-FT) of the received signal can be easily computed. Experimental results concerning an aluminum plate with different hole sizes will be shown. The A0-, S0-, A1-, S1- and S2-modes are generated at the same time. This study shows that the A0 mode seems particularly interesting to detect flaws of this geometrical type.

  18. Coherence analysis using canonical coordinate decomposition with applications to sparse processing and optimal array deployment

    NASA Astrophysics Data System (ADS)

    Azimi-Sadjadi, Mahmood R.; Pezeshki, Ali; Wade, Robert L.

    2004-09-01

    Sparse array processing methods are typically used to improve the spatial resolution of sensor arrays for the estimation of direction of arrival (DOA). The fundamental assumption behind these methods is that signals that are received by the sparse sensors (or a group of sensors) are coherent. However, coherence may vary significantly with the changes in environmental, terrain, and, operating conditions. In this paper canonical correlation analysis is used to study the variations in coherence between pairs of sub-arrays in a sparse array problem. The data set for this study is a subset of an acoustic signature data set, acquired from the US Army TACOM-ARDEC, Picatinny Arsenal, NJ. This data set is collected using three wagon-wheel type arrays with five microphones. The results show that in nominal operating conditions, i.e. no extreme wind noise or masking effects by trees, building, etc., the signals collected at different sensor arrays are indeed coherent even at distant node separation.

  19. Multispectral multisensor image fusion using wavelet transforms

    USGS Publications Warehouse

    Lemeshewsky, George P.

    1999-01-01

    Fusion techniques can be applied to multispectral and higher spatial resolution panchromatic images to create a composite image that is easier to interpret than the individual images. Wavelet transform-based multisensor, multiresolution fusion (a type of band sharpening) was applied to Landsat thematic mapper (TM) multispectral and coregistered higher resolution SPOT panchromatic images. The objective was to obtain increased spatial resolution, false color composite products to support the interpretation of land cover types wherein the spectral characteristics of the imagery are preserved to provide the spectral clues needed for interpretation. Since the fusion process should not introduce artifacts, a shift invariant implementation of the discrete wavelet transform (SIDWT) was used. These results were compared with those using the shift variant, discrete wavelet transform (DWT). Overall, the process includes a hue, saturation, and value color space transform to minimize color changes, and a reported point-wise maximum selection rule to combine transform coefficients. The performance of fusion based on the SIDWT and DWT was evaluated with a simulated TM 30-m spatial resolution test image and a higher resolution reference. Simulated imagery was made by blurring higher resolution color-infrared photography with the TM sensors' point spread function. The SIDWT based technique produced imagery with fewer artifacts and lower error between fused images and the full resolution reference. Image examples with TM and SPOT 10-m panchromatic illustrate the reduction in artifacts due to the SIDWT based fusion.

  20. Kalman filter-based microphone array signal processing using the equivalent source model

    NASA Astrophysics Data System (ADS)

    Bai, Mingsian R.; Chen, Ching-Cheng

    2012-10-01

    This paper demonstrates that microphone array signal processing can be implemented by using adaptive model-based filtering approaches. Nearfield and farfield sound propagation models are formulated into state-space forms in light of the Equivalent Source Method (ESM). In the model, the unknown source amplitudes of the virtual sources are adaptively estimated by using Kalman filters (KFs). The nearfield array aimed at noise source identification is based on a Multiple-Input-Multiple-Output (MIMO) state-space model with minimal realization, whereas the farfield array technique aimed at speech quality enhancement is based on a Single-Input-Multiple-Output (SIMO) state-space model. Performance of the nearfield array is evaluated in terms of relative error of the velocity reconstructed on the actual source surface. Numerical simulations for the nearfield array were conducted with a baffled planar piston source. From the error metric, the proposed KF algorithm proved effective in identifying noise sources. Objective simulations and subjective experiments are undertaken to validate the proposed farfield arrays in comparison with two conventional methods. The results of objective tests indicated that the farfield arrays significantly enhanced the speech quality and word recognition rate. The results of subjective tests post-processed with the analysis of variance (ANOVA) and a post-hoc Fisher's least significant difference (LSD) test have shown great promise in the KF-based microphone array signal processing techniques.

  1. Efficient processing of two-dimensional arrays with C or C++

    USGS Publications Warehouse

    Donato, David I.

    2017-07-20

    Because fast and efficient serial processing of raster-graphic images and other two-dimensional arrays is a requirement in land-change modeling and other applications, the effects of 10 factors on the runtimes for processing two-dimensional arrays with C and C++ are evaluated in a comparative factorial study. This study’s factors include the choice among three C or C++ source-code techniques for array processing; the choice of Microsoft Windows 7 or a Linux operating system; the choice of 4-byte or 8-byte array elements and indexes; and the choice of 32-bit or 64-bit memory addressing. This study demonstrates how programmer choices can reduce runtimes by 75 percent or more, even after compiler optimizations. Ten points of practical advice for faster processing of two-dimensional arrays are offered to C and C++ programmers. Further study and the development of a C and C++ software test suite are recommended.Key words: array processing, C, C++, compiler, computational speed, land-change modeling, raster-graphic image, two-dimensional array, software efficiency

  2. Redundant Disk Arrays in Transaction Processing Systems. Ph.D. Thesis, 1993

    NASA Technical Reports Server (NTRS)

    Mourad, Antoine Nagib

    1994-01-01

    We address various issues dealing with the use of disk arrays in transaction processing environments. We look at the problem of transaction undo recovery and propose a scheme for using the redundancy in disk arrays to support undo recovery. The scheme uses twin page storage for the parity information in the array. It speeds up transaction processing by eliminating the need for undo logging for most transactions. The use of redundant arrays of distributed disks to provide recovery from disasters as well as temporary site failures and disk crashes is also studied. We investigate the problem of assigning the sites of a distributed storage system to redundant arrays in such a way that a cost of maintaining the redundant parity information is minimized. Heuristic algorithms for solving the site partitioning problem are proposed and their performance is evaluated using simulation. We also develop a heuristic for which an upper bound on the deviation from the optimal solution can be established.

  3. Implementation of an Antenna Array Signal Processing Breadboard for the Deep Space Network

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2006-01-01

    The Deep Space Network Large Array will replace/augment 34 and 70 meter antenna assets. The array will mainly be used to support NASA's deep space telemetry, radio science, and navigation requirements. The array project will deploy three complexes in the western U.S., Australia, and European longitude each with 400 12m downlink antennas and a DSN central facility at JPL. THis facility will remotely conduct all real-time monitor and control for the network. Signal processing objectives include: provide a means to evaluate the performance of the Breadboard Array's antenna subsystem; design and build prototype hardware; demonstrate and evaluate proposed signal processing techniques; and gain experience with various technologies that may be used in the Large Array. Results are summarized..

  4. A solar array module fabrication process for HALE solar electric UAVs

    SciTech Connect

    Carey, P.G.; Aceves, R.C.; Colella, N.J.; Thompson, J.B.; Williams, K.A.

    1993-12-01

    We describe a fabrication process to manufacture high power to weight ratio flexible solar array modules for use on high altitude long endurance (HALE) solar electric unmanned air vehicles (UAVs). A span-loaded flying wing vehicle, known as the RAPTOR Pathfinder, is being employed as a flying test bed to expand the envelope of solar powered flight to high altitudes. It requires multiple light weight flexible solar array modules able to endure adverse environmental conditions. At high altitudes the solar UV flux is significantly enhanced relative to sea level, and extreme thermal variations occur. Our process involves first electrically interconnecting solar cells into an array followed by laminating them between top and bottom laminated layers into a solar array module. After careful evaluation of candidate polymers, fluoropolymer materials have been selected as the array laminate layers because of their inherent abilities to withstand the hostile conditions imposed by the environment.

  5. A solar array module fabrication process for HALE solar electric UAVs

    NASA Astrophysics Data System (ADS)

    Carey, P. G.; Aceves, R. C.; Colella, N. J.; Thompson, J. B.; Williams, K. A.

    1993-12-01

    We describe a fabrication process to manufacture high power to weight ratio flexible solar array modules for use on high altitude long endurance (HALE) solar electric unmanned air vehicles (UAV's). A span-loaded flying wing vehicle, known as the RAPTOR Pathfinder, is being employed as a flying test bed to expand the envelope of solar powered flight to high altitudes. It requires multiple light weight, flexible solar array modules able to endure adverse environmental conditions. At high altitudes the solar UV flux is significantly enhanced relative to sea level and extreme thermal variations occur. Our process involves first electrically interconnecting solar cells into an array followed by laminating them between top and bottom laminated layers into a solar array module. After careful evaluation of candidate polymers, fluoropolymer materials have been selected as the array laminate layers because of their inherent abilities to withstand the hostile conditions imposed by the environment.

  6. Multisensor detection and tracking of tactical ballistic missiles using knowledge-based state estimation

    NASA Astrophysics Data System (ADS)

    Woods, Edward; Queeney, Tom

    1994-06-01

    Westinghouse has developed and demonstrated a system that performs multisensor detection and tracking of tactical ballistic missiles (TBM). Under a USAF High Gear Program, we developed knowledge-based techniques to discriminate TBM targets from ground clutter, air breathing targets, and false alarms. Upon track initiation the optimal estimate of the target's launch point, impact point and instantaneous position was computed by fusing returns from noncollocated multiple sensors. The system also distinguishes different missile types during the boost phase and forms multiple hypotheses to account for measurement and knowledge base uncertainties. This paper outlines the salient features of the knowledge-based processing of the multisensor data.

  7. Autonomous navigation vehicle system based on robot vision and multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Wu, Lihong; Chen, Yingsong; Cui, Zhouping

    2011-12-01

    The architecture of autonomous navigation vehicle based on robot vision and multi-sensor fusion technology is expatiated in this paper. In order to acquire more intelligence and robustness, accurate real-time collection and processing of information are realized by using this technology. The method to achieve robot vision and multi-sensor fusion is discussed in detail. The results simulated in several operating modes show that this intelligent vehicle has better effects in barrier identification and avoidance and path planning. And this can provide higher reliability during vehicle running.

  8. Design, processing and testing of LSI arrays, hybrid microelectronics task

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.; Rothrock, C. W.

    1979-01-01

    Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated.

  9. Neural Source Localization Using Advanced Sensor Array Signal Processing Techniques

    DTIC Science & Technology

    2001-10-25

    Singular Value Decomposition ( SVD ) of the spatial covariance matrix MxMjYR ℜ∈ of jY [7]. From a theoretic viewpoint, the information about the neural...source’s spatial amplitude distribution or “footprint” on the array side is contained in this covariance matrix. The SVD allows one to assess the P...Abstract unclassified Limitation of Abstract UU Number of Pages 4 2 of the SVD stage. The last step consists of selecting certain subbands from the full

  10. SAIM: a mobile multisensor image exploitation system

    NASA Astrophysics Data System (ADS)

    Devambez, Francois

    2000-11-01

    The control of information is an essential part of operations. Technology allows today a near real time surveillance capacity, over wide areas, due to sensor performances, communication networks. The system presented herein has been developed by Thomson-Csf, under contract with the French MOD to give to the decision makers the right information, in a very short delay, and prepare support information, to help for decision. The SAIM, Mobile Multisensor Image Exploitation Ground System, uses near real time acquisition units, very large data base management, data processing, including fusion and decision aiding tools, and communication networks. It then helps for all the steps of exploitation of data incoming from image sensors, form preparation of the reconnaissance mission to the dissemination of intelligence. The SAIM system is in operations in the French Air Force, and soon in the French Navy and the French Army. Initially defined for the specific use of French Recce sensors, the SAIM is now intended to be widely used for the exploitation of UAV and battle field MTI and SAR surveillance systems.

  11. Micropatterning microlens arrays fabricated by a femtosecond laser wet etch process

    NASA Astrophysics Data System (ADS)

    Wei, Yang; Yang, Qing; Bian, Hao; Chen, Feng

    2017-02-01

    Microlens arrays with specially required micropatterns are highly desirable for digital optical processors, microimaging systems, optical photolithography as well as various biomedical imaging and detecting applications. However, realization of such devices efficiently remains technically challenging. Here, a facile and efficient route for large-area microlens arrays (MLAs) with programmable micropatterns is demonstrated. The fabrication process involves a femtosecond laser wet etch process combined with the replication process of hot embossing. Special arranged microlens arrays, including a doublet microlens array, a three-microlens group array, a four-microlens group array, and a six-petallike microlens array as examples, were fabricated by this method. The fabricated MLAs exhibit excellent surface morphology quality and optical imaging properties. This presented technique provides an efficient way to flexibly design the size, shape and the arrangement of the MLAs by adjusting the process parameters such as the pulse energy, the number of shots etching time and the distribution of ablation-induced craters and Programming arrangement.

  12. Parallel processing in a host plus multiple array processor system for radar

    NASA Technical Reports Server (NTRS)

    Barkan, B. Z.

    1983-01-01

    Host plus multiple array processor architecture is demonstrated to yield a modular, fast, and cost-effective system for radar processing. Software methodology for programming such a system is developed. Parallel processing with pipelined data flow among the host, array processors, and discs is implemented. Theoretical analysis of performance is made and experimentally verified. The broad class of problems to which the architecture and methodology can be applied is indicated.

  13. High speed vision processor with reconfigurable processing element array based on full-custom distributed memory

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Yang, Jie; Shi, Cong; Qin, Qi; Liu, Liyuan; Wu, Nanjian

    2016-04-01

    In this paper, a hybrid vision processor based on a compact full-custom distributed memory for near-sensor high-speed image processing is proposed. The proposed processor consists of a reconfigurable processing element (PE) array, a row processor (RP) array, and a dual-core microprocessor. The PE array includes two-dimensional processing elements with a compact full-custom distributed memory. It supports real-time reconfiguration between the PE array and the self-organized map (SOM) neural network. The vision processor is fabricated using a 0.18 µm CMOS technology. The circuit area of the distributed memory is reduced markedly into 1/3 of that of the conventional memory so that the circuit area of the vision processor is reduced by 44.2%. Experimental results demonstrate that the proposed design achieves correct functions.

  14. Monolithic optical phased-array transceiver in a standard SOI CMOS process.

    PubMed

    Abediasl, Hooman; Hashemi, Hossein

    2015-03-09

    Monolithic microwave phased arrays are turning mainstream in automotive radars and high-speed wireless communications fulfilling Gordon Moores 1965 prophecy to this effect. Optical phased arrays enable imaging, lidar, display, sensing, and holography. Advancements in fabrication technology has led to monolithic nanophotonic phased arrays, albeit without independent phase and amplitude control ability, integration with electronic circuitry, or including receive and transmit functions. We report the first monolithic optical phased array transceiver with independent control of amplitude and phase for each element using electronic circuitry that is tightly integrated with the nanophotonic components on one substrate using a commercial foundry CMOS SOI process. The 8 × 8 phased array chip includes thermo-optical tunable phase shifters and attenuators, nano-photonic antennas, and dedicated control electronics realized using CMOS transistors. The complex chip includes over 300 distinct optical components and over 74,000 distinct electrical components achieving the highest level of integration for any electronic-photonic system.

  15. View and sensor planning for multi-sensor surface inspection

    NASA Astrophysics Data System (ADS)

    Gronle, Marc; Osten, Wolfgang

    2016-06-01

    Modern manufacturing processes enable the precise fabrication of high-value parts with high precision and performance. At the same time, the demand for flexible on-demand production of individual objects is continuously increasing. These requirements can only be met if inspection systems provide appropriate answers. One solution is the use of flexible, multi-sensor setups where multiple optical sensors with different fields of application are combined in one system. However, the challenge is then to assist the user in planning the inspection for individual parts. A manual planning requires an expert knowledge of the performance and functionality of every sensor. Therefore, software assistant systems help the user to objectively select the right sensors for a given inspection task. The planning step becomes still more difficult if the manufactured part has a complex form. The implication is that a sensor’s position must also be part of the planning process since it significantly influences the quality of the inspection. This paper describes a view and sensor planning approach for a multi-sensor surface inspection system in the context of optical topography measurements in the micro- and meso-scale range. In order to realize an online processing of the assistant system, a significant part of the calculations are done on the graphics processing unit (GPU).

  16. Model-based Processing of Microcantilever Sensor Arrays

    SciTech Connect

    Tringe, J W; Clague, D S; Candy, J V; Sinensky, A K; Lee, C L; Rudd, R E; Burnham, A K

    2005-04-27

    We have developed a model-based processor (MBP) for a microcantilever-array sensor to detect target species in solution. We perform a proof-of-concept experiment, fit model parameters to the measured data and use them to develop a Gauss-Markov simulation. We then investigate two cases of interest, averaged deflection data and multi-channel data. For this evaluation we extract model parameters via a model-based estimation, perform a Gauss-Markov simulation, design the optimal MBP and apply it to measured experimental data. The performance of the MBP in the multi-channel case is evaluated by comparison to a ''smoother'' (averager) typically used for microcantilever signal analysis. It is shown that the MBP not only provides a significant gain ({approx} 80dB) in signal-to-noise ratio (SNR), but also consistently outperforms the smoother by 40-60 dB. Finally, we apply the processor to the smoothed experimental data and demonstrate its capability for chemical detection. The MBP performs quite well, apart from a correctable systematic bias error.

  17. Programmable hyperspectral image mapper with on-array processing

    NASA Technical Reports Server (NTRS)

    Cutts, James A. (Inventor)

    1995-01-01

    A hyperspectral imager includes a focal plane having an array of spaced image recording pixels receiving light from a scene moving relative to the focal plane in a longitudinal direction, the recording pixels being transportable at a controllable rate in the focal plane in the longitudinal direction, an electronic shutter for adjusting an exposure time of the focal plane, whereby recording pixels in an active area of the focal plane are removed therefrom and stored upon expiration of the exposure time, an electronic spectral filter for selecting a spectral band of light received by the focal plane from the scene during each exposure time and an electronic controller connected to the focal plane, to the electronic shutter and to the electronic spectral filter for controlling (1) the controllable rate at which the recording is transported in the longitudinal direction, (2) the exposure time, and (3) the spectral band so as to record a selected portion of the scene through M spectral bands with a respective exposure time t(sub q) for each respective spectral band q.

  18. Precise relative earthquake depth determination using array processing techniques

    NASA Astrophysics Data System (ADS)

    Florez, M. A.; Prieto, G. A.

    2017-06-01

    Precise determination of hypocentral depth remains one of the most relevant problems in earthquake seismology. It is well known that using depth phases allows for significant improvement in event depth determination; however, routinely and systematically picking such phases, for teleseismic or regional arrivals, is problematic due to poor signal-to-noise ratios around the pP and sP phases. To overcome this limitation, we have taken advantage of the additional information carried by seismic arrays. We use velocity spectral analysis to precisely measure pP-P times. The individual estimates obtained at different subarrays, for all pairs of earthquakes, are combined using a double-difference algorithm, in order to precisely map seismicity in regions where it is tightly clustered. We illustrate this method by relocating intermediate-depth earthquakes in the Nazca subducting plate, beneath northern Chile, where we confirm the existence of a narrowly spaced double seismic zone, previously imaged using a local dedicated deployment. As a second example we relocate the aftershock sequence of the 2014 Mw 7.9 intermediate depth, Rat Islands earthquake, and provide evidence of a subvertical fault plane for the main shock. Finally, we show that the resulting relative depth errors are typically smaller than 2 km.

  19. Signal and array processing techniques for RFID readers

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Amin, Moeness; Zhang, Yimin

    2006-05-01

    Radio Frequency Identification (RFID) has recently attracted much attention in both the technical and business communities. It has found wide applications in, for example, toll collection, supply-chain management, access control, localization tracking, real-time monitoring, and object identification. Situations may arise where the movement directions of the tagged RFID items through a portal is of interest and must be determined. Doppler estimation may prove complicated or impractical to perform by RFID readers. Several alternative approaches, including the use of an array of sensors with arbitrary geometry, can be applied. In this paper, we consider direction-of-arrival (DOA) estimation techniques for application to near-field narrowband RFID problems. Particularly, we examine the use of a pair of RFID antennas to track moving RFID tagged items through a portal. With two antennas, the near-field DOA estimation problem can be simplified to a far-field problem, yielding a simple way for identifying the direction of the tag movement, where only one parameter, the angle, needs to be considered. In this case, tracking of the moving direction of the tag simply amounts to computing the spatial cross-correlation between the data samples received at the two antennas. It is pointed out that the radiation patterns of the reader and tag antennas, particularly their phase characteristics, have a significant effect on the performance of DOA estimation. Indoor experiments are conducted in the Radar Imaging and RFID Labs at Villanova University for validating the proposed technique for target movement direction estimations.

  20. Advanced techniques for array processing. Final report, 1 Mar 89-30 Apr 91

    SciTech Connect

    Friedlander, B.

    1991-05-30

    Array processing technology is expected to be a key element in communication systems designed for the crowded and hostile environment of the future battlefield. While advanced array processing techniques have been under development for some time, their practical use has been very limited. This project addressed some of the issues which need to be resolved for a successful transition of these promising techniques from theory into practice. The main problem which was studied was that of finding the directions of multiple co-channel transmitters from measurements collected by an antenna array. Two key issues related to high-resolution direction finding were addressed: effects of system calibration errors, and effects of correlation between the received signals due to multipath propagation. A number of useful theoretical performance analysis results were derived, and computationally efficient direction estimation algorithms were developed. These results include: self-calibration techniques for antenna arrays, sensitivity analysis for high-resolution direction finding, extensions of the root-MUSIC algorithm to arbitrary arrays and to arrays with polarization diversity, and new techniques for direction finding in the presence of multipath based on array interpolation. (Author)

  1. Airborne Multisensor Pod System (AMPS) data management overview

    SciTech Connect

    Wiberg, J.D.; Blough, D.K.; Daugherty, W.R.; Hucks, J.A.; Gerhardstein, L.H.; Meitzler, W.D.; Melton, R.B.; Shoemaker, S.V.

    1994-09-01

    An overview of the Data Management Plan for the Airborne Multisensor Pod System (AMPS) pro-grain is provided in this document. The Pacific Northwest Laboratory (PNL) has been assigned the responsibility of data management for the program, which includes defining procedures for data management and data quality assessment. Data management is defined as the process of planning, acquiring, organizing, qualifying and disseminating data. The AMPS program was established by the U.S. Department of Energy (DOE), Office of Arms Control and Non-Proliferation (DOE/AN) and is integrated into the overall DOE AN-10.1 technology development program. Sensors used for collecting the data were developed under the on-site inspection, effluence analysis, and standoff sensor program, the AMPS program interacts with other technology programs of DOE/NN-20. This research will be conducted by both government and private industry. AMPS is a research and development program, and it is not intended for operational deployment, although the sensors and techniques developed could be used in follow-on operational systems. For a complete description of the AMPS program, see {open_quotes}Airborne Multisensor Pod System (AMPS) Program Plan{close_quotes}. The primary purpose of the AMPS is to collect high-quality multisensor data to be used in data fusion research to reduce interpretation problems associated with data overload and to derive better information than can be derived from any single sensor. To collect the data for the program, three wing-mounted pods containing instruments with sensors for collecting data will be flight certified on a U.S. Navy RP-3A aircraft. Secondary objectives of the AMPS program are sensor development and technology demonstration. Pod system integrators and instrument developers will be interested in the performance of their deployed sensors and their supporting data acquisition equipment.

  2. Intelligent multisensor concept for image-guided 3D object measurement with scanning laser radar

    NASA Astrophysics Data System (ADS)

    Weber, Juergen

    1995-08-01

    This paper presents an intelligent multisensor concept for measuring 3D objects using an image guided laser radar scanner. The field of application are all kinds of industrial inspection and surveillance tasks where it is necessary to detect, measure and recognize 3D objects in distances up to 10 m with high flexibility. Such applications might be the surveillance of security areas or container storages as well as navigation and collision avoidance of autonomous guided vehicles. The multisensor system consists of a standard CCD matrix camera and a 1D laser radar ranger which is mounted to a 2D mirror scanner. With this sensor combination it is possible to acquire gray scale intensity data as well as absolute 3D information. To improve the system performance and flexibility, the intensity data of the scene captured by the camera can be used to focus the measurement of the 3D sensor to relevant areas. The camera guidance of the laser scanner is useful because the acquisition of spatial information is relatively slow compared to the image sensor's ability to snap an image frame in 40 ms. Relevant areas in a scene are located by detecting edges of objects utilizing various image processing algorithms. The complete sensor system is controlled by three microprocessors carrying out the 3D data acquisition, the image processing tasks and the multisensor integration. The paper deals with the details of the multisensor concept. It describes the process of sensor guidance and 3D measurement and presents some practical results of our research.

  3. Tracing Crop Nitrogen Dynamics on the Field-Scale by Combining Multisensoral EO Data with an Integrated Process Model- A Validation Experiment for Cereals in Southern Germany

    NASA Astrophysics Data System (ADS)

    Hank, Tobias B.; Bach, Heike; Danner, Martin; Hodrius, Martina; Mauser, Wolfram

    2016-08-01

    Nitrogen, being the basic element for the construction of plant proteins and pigments, is one of the most important production factors for agricultural cultivation. High resolution and near real-time information on nitrogen status in the soil thus is of highest interest for economically and ecologically optimized fertilizer planning and application. Unfortunately, nitrogen storage in the soil column cannot be directly observed with Earth Observation (EO) instruments. Advanced EO supported process modelling approaches therefore must be applied that allow tracing the spatiotemporal dynamics of nitrogen transformation, translocation and transport in the soil and in the canopy. Before these models can be applied as decision support tools for smart farming, they must be carefully parameterized and validated. This study applies an advanced land surface process model (PROMET) to selected winter cereal fields in Southern Germany and correlates the model outputs to destructively sampled nitrogen data from the growing season of 2015 (17 sampling dates, 8 sample locations). The spatial parametrization of the process model thereby is supported by assimilating eight satellite images (5 times Landsat 8 OLI and 3 times RapidEye). It was found that the model is capable of realistically tracing the temporal and spatial dynamics of aboveground nitrogen uptake and allocation (R2 = 0.84, RMSE 31.3 kg ha-1).

  4. Multisensor multiresolution data fusion for improvement in classification

    NASA Astrophysics Data System (ADS)

    Rubeena, V.; Tiwari, K. C.

    2016-04-01

    The rapid advancements in technology have facilitated easy availability of multisensor and multiresolution remote sensing data. Multisensor, multiresolution data contain complementary information and fusion of such data may result in application dependent significant information which may otherwise remain trapped within. The present work aims at improving classification by fusing features of coarse resolution hyperspectral (1 m) LWIR and fine resolution (20 cm) RGB data. The classification map comprises of eight classes. The class names are Road, Trees, Red Roof, Grey Roof, Concrete Roof, Vegetation, bare Soil and Unclassified. The processing methodology for hyperspectral LWIR data comprises of dimensionality reduction, resampling of data by interpolation technique for registering the two images at same spatial resolution, extraction of the spatial features to improve classification accuracy. In the case of fine resolution RGB data, the vegetation index is computed for classifying the vegetation class and the morphological building index is calculated for buildings. In order to extract the textural features, occurrence and co-occurence statistics is considered and the features will be extracted from all the three bands of RGB data. After extracting the features, Support Vector Machine (SVMs) has been used for training and classification. To increase the classification accuracy, post processing steps like removal of any spurious noise such as salt and pepper noise is done which is followed by filtering process by majority voting within the objects for better object classification.

  5. Irma multisensor predictive signature model

    NASA Astrophysics Data System (ADS)

    Watson, John S.; Wellfare, Michael R.; Foster, Joseph; Owens, Monte A.; Vechinski, Douglas A.; Richards, Mike; Resnick, Andrew; Underwood, Vincent

    1998-07-01

    The Irma synthetic signature model was one of the first high resolution infrared (IR) target and background signature models to be developed for tactical weapons application. Originally developed in 1980 by the Munitions Directorate of the Air Force Research Laboratory, the Irma model was used exclusively to generate IR scenes for smart weapons research and development. In 1988, a number of significant upgrades to Irma were initiated including the addition of a laser channel. This two channel version, Irma 3.0, was released to the user community in 1990. In 1992, an improved scene generator was incorporated into the Irma model which supported correlated frame-to-frame imagery. This and other improvements were released in Irma 2.2. Irma 3.2, a passive IR/millimeter wave (MMW) code, was completed in 1994. This served as the cornerstone for the development of the co- registered active/passive IR/MMW model, Irma 4.0. Currently, upgrades are underway to include a near IR (NIR)/visible channel; a facet editor; utilities to support image viewing and scaling; and additional target/data files. The Irma 4.1 software development effort is nearly completion. The purpose of this paper is to illustrate the results of the development. Planned upgrades for Irma 5.0 will be provided as well. Irma is being developed to facilitate multi-sensor research and development. It is currently being used to support a number of civilian and military applications. The current Irma user base includes over 100 agencies within the Air Force, Army, Navy, DARPA, NASA, Department of Transportation, academia, and industry.

  6. An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study.

    PubMed

    Weinstein, Ronald S; Descour, Michael R; Liang, Chen; Barker, Gail; Scott, Katherine M; Richter, Lynne; Krupinski, Elizabeth A; Bhattacharyya, Achyut K; Davis, John R; Graham, Anna R; Rennels, Margaret; Russum, William C; Goodall, James F; Zhou, Pixuan; Olszak, Artur G; Williams, Bruce H; Wyant, James C; Bartels, Peter H

    2004-11-01

    This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a "lenslet array ensemble." The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single "miniaturized microscope." A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A.= 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete. A validation study compared the diagnostic accuracy of pathologist case readers using array microscopy (with images viewed as virtual slides) and conventional light microscopy. Four senior pathologists diagnosed 30 breast surgical pathology cases each using both imaging modes, but on separate occasions. Of 120 case reads by array microscopy

  7. Assessing the performance of multisensor fusion systems

    NASA Astrophysics Data System (ADS)

    Llinas, James

    1992-04-01

    In recent years, numerous prototypical systems have been developed for multisensor data fusion. A typical data fusion process operates on sensor parametric data (e.g., data related to target position or attribute data) in order to develop an order of battle, provide an evaluation of tactical situations, or assess tactical threats. This model, developed by the Data Fusion Sub- panel (DFS) of the Joint Directors of Laboratories, partitions fusion processing into four conceptual levels. Ancillary functions in a fusion system include the human computer interface, data base management, source-preprocessing functions, and communications. Military applications for data fusion span a broad range including fusion of data on board a single platform for identifying other platforms (e.g., identification--friend or foe--neutral systems), threat warning systems, situation assessment, and threat assessment systems. Large scale systems such as the All-Source Analysis System (ASAS) or the Joint Surveillance, Targeting, and Reconnaissance System (JSTARS) provide for direction, coordination, and fusion of both ground-based and airborne sensors to aid in the effective management of a ground based battlefield environment. Such systems have become ever more sophisticated. Indeed, many of the prototypical systems utilize advanced identification techniques such as knowledge-based or expert systems. Dempster-Shafer interface techniques, adaptive neural networks, and sophisticated tracking algorithms. While much research is being performed to develop and apply new algorithms and techniques, little work has been performed to determine how well such methods work or to compare alternative methods against a common problem. The issues of system performance and system effectiveness are keys to establishing how well an algorithm, technique, or collection of techniques perform, and then the extent to which these techniques may be used to achieve success on an operational mission.

  8. Large-Scale, Parallel, Multi-Sensor Atmospheric Data Fusion Using Cloud Computing

    NASA Astrophysics Data System (ADS)

    Wilson, B. D.; Manipon, G.; Hua, H.; Fetzer, E. J.

    2013-12-01

    NASA's Earth Observing System (EOS) is an ambitious facility for studying global climate change. The mandate now is to combine measurements from the instruments on the 'A-Train' platforms (AIRS, AMSR-E, MODIS, MISR, MLS, and CloudSat) and other Earth probes to enable large-scale studies of climate change over decades. Moving to multi-sensor, long-duration analyses of important climate variables presents serious challenges for large-scale data mining and fusion. For example, one might want to compare temperature and water vapor retrievals from one instrument (AIRS) to another (MODIS), and to a model (MERRA), stratify the comparisons using a classification of the 'cloud scenes' from CloudSat, and repeat the entire analysis over 10 years of data. To efficiently assemble such datasets, we are utilizing Elastic Computing in the Cloud and parallel map/reduce-based algorithms. However, these problems are Data Intensive computing so the data transfer times and storage costs (for caching) are key issues. SciReduce is a Hadoop-like parallel analysis system, programmed in parallel python, that is designed from the ground up for Earth science. SciReduce executes inside VMWare images and scales to any number of nodes in the Cloud. Unlike Hadoop, SciReduce operates on bundles of named numeric arrays, which can be passed in memory or serialized to disk in netCDF4 or HDF5. Figure 1 shows the architecture of the full computational system, with SciReduce at the core. Multi-year datasets are automatically 'sharded' by time and space across a cluster of nodes so that years of data (millions of files) can be processed in a massively parallel way. Input variables (arrays) are pulled on-demand into the Cloud using OPeNDAP URLs or other subsetting services, thereby minimizing the size of the cached input and intermediate datasets. We are using SciReduce to automate the production of multiple versions of a ten-year A-Train water vapor climatology under a NASA MEASURES grant. We will

  9. Large-Scale, Parallel, Multi-Sensor Atmospheric Data Fusion Using Cloud Computing

    NASA Astrophysics Data System (ADS)

    Wilson, B. D.; Manipon, G.; Hua, H.; Fetzer, E.

    2013-05-01

    NASA's Earth Observing System (EOS) is an ambitious facility for studying global climate change. The mandate now is to combine measurements from the instruments on the "A-Train" platforms (AIRS, AMSR-E, MODIS, MISR, MLS, and CloudSat) and other Earth probes to enable large-scale studies of climate change over decades. Moving to multi-sensor, long-duration analyses of important climate variables presents serious challenges for large-scale data mining and fusion. For example, one might want to compare temperature and water vapor retrievals from one instrument (AIRS) to another (MODIS), and to a model (ECMWF), stratify the comparisons using a classification of the "cloud scenes" from CloudSat, and repeat the entire analysis over 10 years of data. To efficiently assemble such datasets, we are utilizing Elastic Computing in the Cloud and parallel map/reduce-based algorithms. However, these problems are Data Intensive computing so the data transfer times and storage costs (for caching) are key issues. SciReduce is a Hadoop-like parallel analysis system, programmed in parallel python, that is designed from the ground up for Earth science. SciReduce executes inside VMWare images and scales to any number of nodes in the Cloud. Unlike Hadoop, SciReduce operates on bundles of named numeric arrays, which can be passed in memory or serialized to disk in netCDF4 or HDF5. Figure 1 shows the architecture of the full computational system, with SciReduce at the core. Multi-year datasets are automatically "sharded" by time and space across a cluster of nodes so that years of data (millions of files) can be processed in a massively parallel way. Input variables (arrays) are pulled on-demand into the Cloud using OPeNDAP URLs or other subsetting services, thereby minimizing the size of the cached input and intermediate datasets. We are using SciReduce to automate the production of multiple versions of a ten-year A-Train water vapor climatology under a NASA MEASURES grant. We will

  10. Matched Field Processing Based on Least Squares with a Small Aperture Hydrophone Array

    PubMed Central

    Wang, Qi; Wang, Yingmin; Zhu, Guolei

    2016-01-01

    The receiver hydrophone array is the signal front-end and plays an important role in matched field processing, which usually covers the whole water column from the sea surface to the bottom. Such a large aperture array is very difficult to realize. To solve this problem, an approach called matched field processing based on least squares with a small aperture hydrophone array is proposed, which decomposes the received acoustic fields into depth function matrix and amplitudes of the normal modes at the beginning. Then all the mode amplitudes are estimated using the least squares in the sense of minimum norm, and the amplitudes estimated are used to recalculate the received acoustic fields of the small aperture array, which means the recalculated ones contain more environmental information. In the end, lots of numerical experiments with three small aperture arrays are processed in the classical shallow water, and the performance of matched field passive localization is evaluated. The results show that the proposed method can make the recalculated fields contain more acoustic information of the source, and the performance of matched field passive localization with small aperture array is improved, so the proposed algorithm is proved to be effective. PMID:28042828

  11. Matched Field Processing Based on Least Squares with a Small Aperture Hydrophone Array.

    PubMed

    Wang, Qi; Wang, Yingmin; Zhu, Guolei

    2016-12-30

    The receiver hydrophone array is the signal front-end and plays an important role in matched field processing, which usually covers the whole water column from the sea surface to the bottom. Such a large aperture array is very difficult to realize. To solve this problem, an approach called matched field processing based on least squares with a small aperture hydrophone array is proposed, which decomposes the received acoustic fields into depth function matrix and amplitudes of the normal modes at the beginning. Then all the mode amplitudes are estimated using the least squares in the sense of minimum norm, and the amplitudes estimated are used to recalculate the received acoustic fields of the small aperture array, which means the recalculated ones contain more environmental information. In the end, lots of numerical experiments with three small aperture arrays are processed in the classical shallow water, and the performance of matched field passive localization is evaluated. The results show that the proposed method can make the recalculated fields contain more acoustic information of the source, and the performance of matched field passive localization with small aperture array is improved, so the proposed algorithm is proved to be effective.

  12. Multisensor fusion for 3-D defect characterization using wavelet basis function neural networks

    NASA Astrophysics Data System (ADS)

    Lim, Jaein; Udpa, Satish S.; Udpa, Lalita; Afzal, Muhammad

    2001-04-01

    The primary objective of multi-sensor data fusion, which offers both quantitative and qualitative benefits, has the ability to draw inferences that may not be feasible with data from a single sensor alone. In this paper, data from two sets of sensors are fused to estimate the defect profile from magnetic flux leakage (MFL) inspection data. The two sensors measure the axial and circumferential components of the MFL. Data is fused at the signal level. If the flux is oriented axially, the samples of the axial signal are measured along a direction parallel to the flaw, while the circumferential signal is measured in a direction that is perpendicular to the flaw. The two signals are combined as the real and imaginary components of a complex valued signal. Signals from an array of sensors are arranged in contiguous rows to obtain a complex valued image. A boundary extraction algorithm is used to extract the defect areas in the image. Signals from the defect regions are then processed to minimize noise and the effects of lift-off. Finally, a wavelet basis function (WBF) neural network is employed to map the complex valued image appropriately to obtain the geometrical profile of the defect. The feasibility of the approach was evaluated using the data obtained from the MFL inspection of natural gas transmission pipelines. Results show the effectiveness of the approach.

  13. Site Specific Evaluation of Multisensor Capacitance Probes

    USDA-ARS?s Scientific Manuscript database

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  14. Application of high-precision matching about multisensor in fast stereo imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Huijing; Zhou, Mei; Wu, Haohao; Zhang, Dandan

    2015-10-01

    High precision matching of linear array multi-sensor is the key to ensure fast stereo imaging. This paper has presented the general principle of active and passive imaging sensor, designed a high precision matching calibration system of linear array multi-sensor based on large-diameter collimator combined with assisted laser light source, and put forward an optical axis parallelism calibration technology suitable for linear array active and passive imaging sensor. This technology makes use of image acquisition system to obtain spot center, in order to match multi-linear array laser receive and transmit optical axes. At the same time, this paper uses linear visible light sources to extract the optical axis of the laser, then completes the parallelism calibration between lasers receive and transmit optical axes of multi-linear array sensors and active and passive optical axis. The matching relationship between the visible pixel and laser radar detecting element can be obtained when using this technique to calibrate the active and passive imaging sensor. And this relationship is applied to the fast stereo imaging experiment of active and passive imaging sensor and gained good imaging effect.

  15. A large-scale interactive one-dimensional array processing system. [for spectrophotometric data

    NASA Technical Reports Server (NTRS)

    Clark, R. N.

    1980-01-01

    The work describes a scientist/user oriented interactive program for processing one-dimensional arrays. It is shown that the program is oriented toward processing spectrophotometric astronomical data and can also be used for general I-D array processing. Further, the program has totally free format input with a sophisticated decoding capability which can cope with typographical plus other possible mistakes. Finally, a description of the program is given to provide information on implementing a large-scale data-reduction facility.

  16. Electro-optical processing of phased array data

    NASA Technical Reports Server (NTRS)

    Casasent, D.

    1973-01-01

    An on-line spatial light modulator for application as the input transducer for a real-time optical data processing system is described. The use of such a device in the analysis and processing of radar data in real time is reported. An interface from the optical processor to a control digital computer was designed, constructed, and tested. The input transducer, optical system, and computer interface have been operated in real time with real time radar data with the input data returns recorded on the input crystal, processed by the optical system, and the output plane pattern digitized, thresholded, and outputted to a display and storage in the computer memory. The correlation of theoretical and experimental results is discussed.

  17. Infrared focal plane array incorporating silicon IC process compatible bolometer

    SciTech Connect

    Tanaka, Akio; Matsumoto, Shouhei; Tsukamoto, Nanao

    1996-11-01

    A 128 x 128 element bolometer infrared image sensor using thin film titanium is proposed. The device is a monolithically integrated structure with a titanium bolometer detector located over a CMOS circuit that reads out the bolometer`s signals. By employing a metallic material like titanium and refining the CMOS readout circuit, it is possible to minimize 1/f noise. It is demonstrated that the use of low 1/f noise materials will help increase bias current and improve the S/N ratio. Since the fabrication process is silicon-process compatible, costs can be kept low.

  18. Reducing multi-sensor data to a single time course that reveals experimental effects

    PubMed Central

    2013-01-01

    Background Multi-sensor technologies such as EEG, MEG, and ECoG result in high-dimensional data sets. Given the high temporal resolution of such techniques, scientific questions very often focus on the time-course of an experimental effect. In many studies, researchers focus on a single sensor or the average over a subset of sensors covering a “region of interest” (ROI). However, single-sensor or ROI analyses ignore the fact that the spatial focus of activity is constantly changing, and fail to make full use of the information distributed over the sensor array. Methods We describe a technique that exploits the optimality and simplicity of matched spatial filters in order to reduce experimental effects in multivariate time series data to a single time course. Each (multi-sensor) time sample of each trial is replaced with its projection onto a spatial filter that is matched to an observed experimental effect, estimated from the remaining trials (Effect-Matched Spatial filtering, or EMS filtering). The resulting set of time courses (one per trial) can be used to reveal the temporal evolution of an experimental effect, which distinguishes this approach from techniques that reveal the temporal evolution of an anatomical source or region of interest. Results We illustrate the technique with data from a dual-task experiment and use it to track the temporal evolution of brain activity during the psychological refractory period. We demonstrate its effectiveness in separating the means of two experimental conditions, and in significantly improving the signal-to-noise ratio at the single-trial level. It is fast to compute and results in readily-interpretable time courses and topographies. The technique can be applied to any data-analysis question that can be posed independently at each sensor, and we provide one example, using linear regression, that highlights the versatility of the technique. Conclusion The approach described here combines established techniques in a

  19. X-ray imaging sensor arrays on foil using solution processed organic photodiodes and organic transistors

    NASA Astrophysics Data System (ADS)

    Kumar, Abhishek; Moet, Date; van der Steen, Jan-Laurens; Tripathi, Ashutosh; Rodriguez, Francisco G.; Maas, Joris; Simon, Matthias; Reutten, Walter; Douglas, Alexander; Raaijmakers, Rob; Malinowski, Pawel E.; Myny, Kris; Shafique, Umar; Andriessen, Ronn; Heremans, Paul; Gelinck, Gerwin

    2014-05-01

    We demonstrate organic imaging sensor arrays fabricated on flexible plastic foil with the solution processing route for both photodiodes and thin film transistors. We used the photovoltaic P3HT:PCBM blend for fabricating the photodiodes using spin coating and pentacene as semiconductor material for the TFTs. Photodiodes fabricated with P3HT:PCBM absorb in the green part of the visible spectrum which matches with the typical scintillator output wavelength. The arrays consist of 32x32 pixels with variation in pixel resolution of 200μmx200μm, 300μmx300μm and of 1mmx1mm. The accurate reproducibility of shadow images of the objects demonstrates the potential of these arrays for imaging purposes. We also demonstrate that the crosstalk is relatively insignificant despite the fact that the active photodiode forms a continuous layer in the array. Since both photodiodes and TFTs are made of organic material, they are processed at low temperatures below 150°C on foil which means that these imaging sensors can be flexible, light weight and low cost when compared to conventional amorphous silicon based imaging sensors on rigid substrates. In combination with a scintillator on top of the arrays, we show the potential of these arrays for the X-ray imaging applications.

  20. Assembly and Integration Process of the First High Density Detector Array for the Atacama Cosmology Telescope

    NASA Technical Reports Server (NTRS)

    Li, Yaqiong; Choi, Steve; Ho, Shuay-Pwu; Crowley, Kevin T.; Salatino, Maria; Simon, Sara M.; Staggs, Suzanne T.; Nati, Federico; Wollack, Edward J.

    2016-01-01

    The Advanced ACTPol (AdvACT) upgrade on the Atacama Cosmology Telescope (ACT) consists of multichroicTransition Edge Sensor (TES) detector arrays to measure the Cosmic Microwave Background (CMB) polarization anisotropies in multiple frequency bands. The first AdvACT detector array, sensitive to both 150 and 230 GHz, is fabricated on a 150 mm diameter wafer and read out with a completely different scheme compared to ACTPol. Approximately 2000 TES bolometers are packed into the wafer leading to both a much denser detector density and readout circuitry. The demonstration of the assembly and integration of the AdvACT arrays is important for the next generation CMB experiments, which will continue to increase the pixel number and density. We present the detailed assembly process of the first AdvACT detector array.

  1. Assembly and Integration Process of the First High Density Detector Array for the Atacama Cosmology Telescope

    NASA Technical Reports Server (NTRS)

    Li, Yaqiong; Choi, Steve; Ho, Shuay-Pwu; Crowley, Kevin T.; Salatino, Maria; Simon, Sara M.; Staggs, Suzanne T.; Nati, Federico; Wollack, Edward J.

    2016-01-01

    The Advanced ACTPol (AdvACT) upgrade on the Atacama Cosmology Telescope (ACT) consists of multichroicTransition Edge Sensor (TES) detector arrays to measure the Cosmic Microwave Background (CMB) polarization anisotropies in multiple frequency bands. The first AdvACT detector array, sensitive to both 150 and 230 GHz, is fabricated on a 150 mm diameter wafer and read out with a completely different scheme compared to ACTPol. Approximately 2000 TES bolometers are packed into the wafer leading to both a much denser detector density and readout circuitry. The demonstration of the assembly and integration of the AdvACT arrays is important for the next generation CMB experiments, which will continue to increase the pixel number and density. We present the detailed assembly process of the first AdvACT detector array.

  2. Assembly and integration process of the first high density detector array for the Atacama Cosmology Telescope

    NASA Astrophysics Data System (ADS)

    Li, Yaqiong; Choi, Steve; Ho, Shuay-Pwu; Crowley, Kevin T.; Salatino, Maria; Simon, Sara M.; Staggs, Suzanne T.; Nati, Federico; Ward, Jonathan; Schmitt, Benjamin L.; Henderson, Shawn; Koopman, Brian J.; Gallardo, Patricio A.; Vavagiakis, Eve M.; Niemack, Michael D.; McMahon, Jeff; Duff, Shannon M.; Schillaci, Alessandro; Hubmayr, Johannes; Hilton, Gene C.; Beall, James A.; Wollack, Edward J.

    2016-07-01

    The Advanced ACTPol (AdvACT) upgrade on the Atacama Cosmology Telescope (ACT) consists of multichroic Transition Edge Sensor (TES) detector arrays to measure the Cosmic Microwave Background (CMB) polarization anisotropies in multiple frequency bands. The first AdvACT detector array, sensitive to both 150 and 230 GHz, is fabricated on a 150 mm diameter wafer and read out with a completely different scheme compared to ACTPol. Approximately 2000 TES bolometers are packed into the wafer leading to both a much denser detector density and readout circuitry. The demonstration of the assembly and integration of the AdvACT arrays is important for the next generation CMB experiments, which will continue to increase the pixel number and density. We present the detailed assembly process of the first AdvACT detector array.

  3. Asymmetric magnetization reversal process in Co nanohill arrays

    SciTech Connect

    Rosa, W. O.; Martinez, L.; Jaafar, M.; Asenjo, A.; Vazquez, M.

    2009-11-15

    Co thin films deposited by sputtering onto nanostructured polymer [poly(methyl methacrylate)] were prepared following replica-antireplica process based on porous alumina membrane. In addition, different capping layers were deposited onto Co nanohills. Morphological and compositional analysis was performed by atomic force microscopy and x-ray photoemission spectroscopy techniques to obtain information about the surface characteristics. The observed asymmetry in the magnetization reversal process at low temperatures is ascribed to the exchange bias generated by the ferromagnetic-antiferromagnetic interface promoted by the presence of Co oxide detected in all the samples. Especially relevant is the case of the Cr capping, where an enhanced magnetic anisotropy in the Co/Cr interface is deduced.

  4. Design, processing and testing of LSI arrays: Hybrid microelectronics task

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.

    1979-01-01

    Mathematical cost factors were generated for both hybrid microcircuit and printed wiring board packaging methods. A mathematical cost model was created for analysis of microcircuit fabrication costs. The costing factors were refined and reduced to formulae for computerization. Efficient methods were investigated for low cost packaging of LSI devices as a function of density and reliability. Technical problem areas such as wafer bumping, inner/outer leading bonding, testing on tape, and tape processing, were investigated.

  5. Optical Digital Algebraic Processing for Multi-Sensor-Array Data.

    DTIC Science & Technology

    1986-02-01

    kAC-AlE? L96 OPTICAL DIGITAL ALGEBRAIC PROCESSING FOR I NMULTI-SENiSOR-ARRARY DATA(U) GEORGIA INST OF TECH ATLANTA SCHOOL OF ELECTRICAL ENGINEERING N...PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT , TASK Georgia Institute of Technology AREA ORKUN, UERS School of Electrical... Engineering Fur Atlanta, Georgia 30332 _ ____-_’_-_ II CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE AFOSR/WN& February 1986 Building 410 1s

  6. Array Processing for Radar Clutter Reduction and Imaging of Ice-Bed Interface

    NASA Astrophysics Data System (ADS)

    Gogineni, P.; Leuschen, C.; Li, J.; Hoch, A.; Rodriguez-Morales, F.; Ledford, J.; Jezek, K.

    2007-12-01

    A major challenge in sounding of fast-flowing glaciers in Greenland and Antarctica is surface clutter, which masks weak returns from the ice-bed interface. The surface clutter is also a major problem in sounding and imaging sub-surface interfaces on Mars and other planets. We successfully applied array-processing techniques to reduce clutter and image ice-bed interfaces of polar ice sheets. These techniques and tools have potential applications to planetary observations. We developed a radar with array-processing capability to measure thickness of fast-flowing outlet glaciers and image the ice-bed interface. The radar operates over the frequency range from 140 to 160 MHz with about an 800- Watt peak transmit power with transmit and receive antenna arrays. The radar is designed such that pulse width and duration are programmable. The transmit-antenna array is fed with a beamshaping network to obtain low sidelobes. We designed the receiver such that it can process and digitize signals for each element of an eight- channel array. We collected data over several fast-flowing glaciers using a five-element antenna array, limited by available hardpoints to mount antennas, on a Twin Otter aircraft during the 2006 field season and a four-element array on a NASA P-3 aircraft during the 2007 field season. We used both adaptive and non-adaptive signal-processing algorithms to reduce clutter. We collected data over the Jacobshavn Isbrae and other fast-flowing outlet glaciers, and successfully measured the ice thickness and imaged the ice-bed interface. In this paper, we will provide a brief description of the radar, discuss clutter-reduction algorithms, present sample results, and discuss the application of these techniques to planetary observations.

  7. Efficient Data Capture and Post-Processing for Real-Time Imaging Using AN Ultrasonic Array

    NASA Astrophysics Data System (ADS)

    Moreau, L.; Hunter, A. J.; Drinkwater, B. W.; Wilcox, P. D.

    2010-02-01

    Over the past few years, ultrasonic phased arrays have shown good potential for nondestructive testing (NDT), thanks to high resolution imaging algorithms. Many algorithms are based on the full matrix capture, obtained by firing each element of an ultrasonic array independently, and collecting the data with all elements. Because of the finite sound velocity in the specimen, two consecutive firings must be separated by a minimum time interval. Therefore, more array elements require longer data acquisition times. Moreover, if the array has N elements, then the full matrix contains N2 temporal signals to be processed. Because of the limited calculation speed of current computers, a large matrix of data can result in long post-processing times. In an industrial context where real-time imaging is desirable, it is crucial to reduce acquisition and/or post-processing times. This paper investigates methods designed to reduce acquisition and post-processing times for the total focusing method and wavenumber imaging algorithms. Limited transmission cycles are used to reduce data capture and post-processing. Post-processing times are further reduced by demodulating the data to temporal baseband frequencies. Results are presented so that a compromise can be made between acquisition time, post-processing time and image quality.

  8. Design, processing, and testing of LSI arrays for space station

    NASA Technical Reports Server (NTRS)

    Schneider, W. C.

    1974-01-01

    The development of a beam-leaded low power, high performance metal-oxide-semiconductor (MOS), 256-bit random access memory (RAM) was reported. Previous success with the aluminum-gate current-sense version and a silicon-gate voltage-sense version led to the present effort to make a beam-leaded silicon-gate RAM. Some problems unique to the silicon-on-sapphire beam-lead process development are presented. Beam-leaded SOS TA5388 devices using a Si3N4 passivation layer were shown to have good electrical parameters.

  9. Automated Source Depth Estimation Using Array Processing Techniques

    DTIC Science & Technology

    2009-10-14

    Processing Techniques W.N. Junek, J. Roman- Nieves , R.C. Kemerait, M.T. Woods, and J.P. Creasey 14 October 2009 Approved for public release; Distribution...NUMBER W.N. Junek, J. Roman- Nieves , R.C. Kemerait, M.T. Woods, and J.P. Creasey 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...2006 American Geophysical Union Conference, San Francisco, CA. Junek, W.N., J. Roman- Nieves , R.C. Kemerait, M.T. Woods, and J.P. Creasey, (2007

  10. Design, processing, and testing of lsi arrays for space station

    NASA Technical Reports Server (NTRS)

    Lile, W. R.; Hollingsworth, R. J.

    1972-01-01

    The design of a MOS 256-bit Random Access Memory (RAM) is discussed. Technological achievements comprise computer simulations that accurately predict performance; aluminum-gate COS/MOS devices including a 256-bit RAM with current sensing; and a silicon-gate process that is being used in the construction of a 256-bit RAM with voltage sensing. The Si-gate process increases speed by reducing the overlap capacitance between gate and source-drain, thus reducing the crossover capacitance and allowing shorter interconnections. The design of a Si-gate RAM, which is pin-for-pin compatible with an RCA bulk silicon COS/MOS memory (type TA 5974), is discussed in full. The Integrated Circuit Tester (ICT) is limited to dc evaluation, but the diagnostics and data collecting are under computer control. The Silicon-on-Sapphire Memory Evaluator (SOS-ME, previously called SOS Memory Exerciser) measures power supply drain and performs a minimum number of tests to establish operation of the memory devices. The Macrodata MD-100 is a microprogrammable tester which has capabilities of extensive testing at speeds up to 5 MHz. Beam-lead technology was successfully integrated with SOS technology to make a simple device with beam leads. This device and the scribing are discussed.

  11. Calibrating a novel multi-sensor physical activity measurement system

    PubMed Central

    John, D; Liu, S; Sasaki, J E; Howe, C A; Staudenmayer, J; Gao, R X; Freedson, P S

    2011-01-01

    Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper, describes a novel multi-sensor ‘Integrated PA Measurement System’ (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors vs. outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance feasibility of free-living use are proposed and refinement of the prediction techniques is discussed. PMID:21813941

  12. Quality assessment for multitemporal and multisensor image fusion

    NASA Astrophysics Data System (ADS)

    Ehlers, Manfred; Klonus, Sascha

    2008-10-01

    Generally, image fusion methods are classified into three levels: pixel level (iconic), feature level (symbolic) and knowledge or decision level. In this paper we focus on iconic techniques for image fusion. There exist a number of established fusion techniques that can be used to merge high spatial resolution panchromatic and lower spatial resolution multispectral images that are simultaneously recorded by one sensor. This is done to create high resolution multispectral image datasets (pansharpening). In most cases, these techniques provide very good results, i.e. they retain the high spatial resolution of the panchromatic image and the spectral information from the multispectral image. These techniques, when applied to multitemporal and/or multisensoral image data, still create spatially enhanced datasets but usually at the expense of the spectral consistency. In this study, a series of nine multitemporal multispectral remote sensing images (seven SPOT scenes and one FORMOSAT scene) is fused with one panchromatic Ikonos image. A number of techniques are employed to analyze the quality of the fusion process. The images are visually and quantitatively evaluated for spectral characteristics preservation and for spatial resolution improvement. Overall, the Ehlers fusion which was developed for spectral characteristics preservation for multi-date and multi-sensor fusion showed the best results. It could not only be proven that the Ehlers fusion is superior to all other tested algorithms but also the only one that guarantees an excellent color preservation for all dates and sensors.

  13. Application of Kalman Filter on Multisensor Fusion Tracking

    DTIC Science & Technology

    1992-12-01

    AD-A257 335 NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC ELCT THESIS APPLICATION OF KALMAN FILTER ON MULTISENSOR FUSION TRACKING by Brian...WORK UNIT ELEMENT NO NO NO ACCESSION NO 11 TITLE (Include Security Classification) PPLICATION OF KALMAN FILTER ON MULTISENSOR FUSION TRACKING 12...FIELD GROUP SUB-GROUP fusion, Kalman Filter Multisensor Fusion Tracking 19 ABSTRACT (Continue on reverse if necessary and identify by block number)he

  14. Root crack sizing using phased array inspections and autoregressive spectral extrapolation signal processing

    NASA Astrophysics Data System (ADS)

    Caldwell, J.; Shakibi, B.; Moles, M.; Sinclair, A. N.

    2013-01-01

    Phased array inspection was conducted on a V-butt welded steel sample with multiple shallow flaws of varying depths. The inspection measurements were processed using Wiener filtering and Autoregressive Spectral Extrapolation (AS) to enhance the signals. Phased array inspections were conducted using multiple phased array probes of varying nominal central frequencies (2.25, 4, 5 and 10 MHz). This paper describes the measured results, which show high accuracy, typically in the range of 0.1-0.2 mm. The results concluded that: 1. There was no statistical difference between the calculated flaw depths from phased array inspections at different flaw tip angles. 2. There was no statistical difference in flaw depths calculated using phased array data collected from either side of the weld. 3. Flaws with depths less than the estimated probe signal shear wavelength could not be sized. 4. Finally, there was no statistical difference in the calculated flaw depths using phased array probes with different sampling frequencies and destructive measurements of the flaws.

  15. Microphone Array Phased Processing System (MAPPS): Version 4.0 Manual

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Mosher, Marianne; Barnes, Michael; Bardina, Jorge

    1999-01-01

    A processing system has been developed to meet increasing demands for detailed noise measurement of individual model components. The Microphone Array Phased Processing System (MAPPS) uses graphical user interfaces to control all aspects of data processing and visualization. The system uses networked parallel computers to provide noise maps at selected frequencies in a near real-time testing environment. The system has been successfully used in the NASA Ames 7- by 10-Foot Wind Tunnel.

  16. DAMAS Processing for a Phased Array Study in the NASA Langley Jet Noise Laboratory

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M.; Plassman, Gerald e.

    2010-01-01

    A jet noise measurement study was conducted using a phased microphone array system for a range of jet nozzle configurations and flow conditions. The test effort included convergent and convergent/divergent single flow nozzles, as well as conventional and chevron dual-flow core and fan configurations. Cold jets were tested with and without wind tunnel co-flow, whereas, hot jets were tested only with co-flow. The intent of the measurement effort was to allow evaluation of new phased array technologies for their ability to separate and quantify distributions of jet noise sources. In the present paper, the array post-processing method focused upon is DAMAS (Deconvolution Approach for the Mapping of Acoustic Sources) for the quantitative determination of spatial distributions of noise sources. Jet noise is highly complex with stationary and convecting noise sources, convecting flows that are the sources themselves, and shock-related and screech noise for supersonic flow. The analysis presented in this paper addresses some processing details with DAMAS, for the array positioned at 90 (normal) to the jet. The paper demonstrates the applicability of DAMAS and how it indicates when strong coherence is present. Also, a new approach to calibrating the array focus and position is introduced and demonstrated.

  17. Array Signal Processing Under Model Errors With Application to Speech Separation

    DTIC Science & Technology

    1992-10-31

    Acoust. Speech Sig. Proc., pp. 1149-1152, Alburqueque NM, 1990. [37] E. A. Patrick , Fundamentals of Pattern Recognition, Englewood Cliffs, NJ, 1972...Proc., Toronto, pp. 1365-1368, 1991. [411 S. U. Pillai , Array Signal Processing, Springer Verlag, NY, 1989. [42] B. Porat and B. Friedlander

  18. An Undergraduate Course and Laboratory in Digital Signal Processing with Field Programmable Gate Arrays

    ERIC Educational Resources Information Center

    Meyer-Base, U.; Vera, A.; Meyer-Base, A.; Pattichis, M. S.; Perry, R. J.

    2010-01-01

    In this paper, an innovative educational approach to introducing undergraduates to both digital signal processing (DSP) and field programmable gate array (FPGA)-based design in a one-semester course and laboratory is described. While both DSP and FPGA-based courses are currently present in different curricula, this integrated approach reduces the…

  19. Assessment of low-cost manufacturing process sequences. [photovoltaic solar arrays

    NASA Technical Reports Server (NTRS)

    Chamberlain, R. G.

    1979-01-01

    An extensive research and development activity to reduce the cost of manufacturing photovoltaic solar arrays by a factor of approximately one hundred is discussed. Proposed and actual manufacturing process descriptions were compared to manufacturing costs. An overview of this methodology is presented.

  20. Effects of process parameters on the molding quality of the micro-needle array

    NASA Astrophysics Data System (ADS)

    Qiu, Z. J.; Ma, Z.; Gao, S.

    2016-07-01

    Micro-needle array, which is used in medical applications, is a kind of typical injection molded products with microstructures. Due to its tiny micro-features size and high aspect ratios, it is more likely to produce short shots defects, leading to poor molding quality. The injection molding process of the micro-needle array was studied in this paper to find the effects of the process parameters on the molding quality of the micro-needle array and to provide theoretical guidance for practical production of high-quality products. With the shrinkage ratio and warpage of micro needles as the evaluation indices of the molding quality, the orthogonal experiment was conducted and the analysis of variance was carried out. According to the results, the contribution rates were calculated to determine the influence of various process parameters on molding quality. The single parameter method was used to analyse the main process parameter. It was found that the contribution rate of the holding pressure on shrinkage ratio and warpage reached 83.55% and 94.71% respectively, far higher than that of the other parameters. The study revealed that the holding pressure is the main factor which affects the molding quality of micro-needle array so that it should be focused on in order to obtain plastic parts with high quality in the practical production.

  1. An Undergraduate Course and Laboratory in Digital Signal Processing with Field Programmable Gate Arrays

    ERIC Educational Resources Information Center

    Meyer-Base, U.; Vera, A.; Meyer-Base, A.; Pattichis, M. S.; Perry, R. J.

    2010-01-01

    In this paper, an innovative educational approach to introducing undergraduates to both digital signal processing (DSP) and field programmable gate array (FPGA)-based design in a one-semester course and laboratory is described. While both DSP and FPGA-based courses are currently present in different curricula, this integrated approach reduces the…

  2. Adaptive multisensor fusion for planetary exploration rovers

    NASA Technical Reports Server (NTRS)

    Collin, Marie-France; Kumar, Krishen; Pampagnin, Luc-Henri

    1992-01-01

    The purpose of the adaptive multisensor fusion system currently being designed at NASA/Johnson Space Center is to provide a robotic rover with assured vision and safe navigation capabilities during robotic missions on planetary surfaces. Our approach consists of using multispectral sensing devices ranging from visible to microwave wavelengths to fulfill the needs of perception for space robotics. Based on the illumination conditions and the sensors capabilities knowledge, the designed perception system should automatically select the best subset of sensors and their sensing modalities that will allow the perception and interpretation of the environment. Then, based on reflectance and emittance theoretical models, the sensor data are fused to extract the physical and geometrical surface properties of the environment surface slope, dielectric constant, temperature and roughness. The theoretical concepts, the design and first results of the multisensor perception system are presented.

  3. Assembly, integration, and verification (AIV) in ALMA: series processing of array elements

    NASA Astrophysics Data System (ADS)

    Lopez, Bernhard; Jager, Rieks; Whyborn, Nicholas D.; Knee, Lewis B. G.; McMullin, Joseph P.

    2012-09-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is a joint project between astronomical organizations in Europe, North America, and East Asia, in collaboration with the Republic of Chile. ALMA will consist of at least 54 twelve-meter antennas and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range. It is the responsibility of ALMA AIV to deliver the fully assembled, integrated, and verified antennas (array elements) to the telescope array. After an initial phase of infrastructure setup AIV activities began when the first ALMA antenna and subsystems became available in mid 2008. During the second semester of 2009 a project-wide effort was made to put in operation a first 3- antenna interferometer at the Array Operations Site (AOS). In 2010 the AIV focus was the transition from event-driven activities towards routine series production. Also, due to the ramp-up of operations activities, AIV underwent an organizational change from an autonomous department into a project within a strong matrix management structure. When the subsystem deliveries stabilized in early 2011, steady-state series processing could be achieved in an efficient and reliable manner. The challenge today is to maintain this production pace until completion towards the end of 2013. This paper describes the way ALMA AIV evolved successfully from the initial phase to the present steady-state of array element series processing. It elaborates on the different project phases and their relationships, presents processing statistics, illustrates the lessons learned and relevant best practices, and concludes with an outlook of the path towards completion.

  4. Astronomical Data Processing Using SciQL, an SQL Based Query Language for Array Data

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Scheers, B.; Kersten, M.; Ivanova, M.; Nes, N.

    2012-09-01

    SciQL (pronounced as ‘cycle’) is a novel SQL-based array query language for scientific applications with both tables and arrays as first class citizens. SciQL lowers the entrance fee of adopting relational DBMS (RDBMS) in scientific domains, because it includes functionality often only found in mathematics software packages. In this paper, we demonstrate the usefulness of SciQL for astronomical data processing using examples from the Transient Key Project of the LOFAR radio telescope. In particular, how the LOFAR light-curve database of all detected sources can be constructed, by correlating sources across the spatial, frequency, time and polarisation domains.

  5. Multisensor benchmark data for riot control

    NASA Astrophysics Data System (ADS)

    Jäger, Uwe; Höpken, Marc; Dürr, Bernhard; Metzler, Jürgen; Willersinn, Dieter

    2008-10-01

    Quick and precise response is essential for riot squads when coping with escalating violence in crowds. Often it is just a single person, known as the leader of the gang, who instigates other people and thus is responsible of excesses. Putting this single person out of action in most cases leads to a de-escalating situation. Fostering de-escalations is one of the main tasks of crowd and riot control. To do so, extensive situation awareness is mandatory for the squads and can be promoted by technical means such as video surveillance using sensor networks. To develop software tools for situation awareness appropriate input data with well-known quality is needed. Furthermore, the developer must be able to measure algorithm performance and ongoing improvements. Last but not least, after algorithm development has finished and marketing aspects emerge, meeting of specifications must be proved. This paper describes a multisensor benchmark which exactly serves this purpose. We first define the underlying algorithm task. Then we explain details about data acquisition and sensor setup and finally we give some insight into quality measures of multisensor data. Currently, the multisensor benchmark described in this paper is applied to the development of basic algorithms for situational awareness, e.g. tracking of individuals in a crowd.

  6. Adaptive and mobile ground sensor array.

    SciTech Connect

    Holzrichter, Michael Warren; O'Rourke, William T.; Zenner, Jennifer; Maish, Alexander B.

    2003-12-01

    The goal of this LDRD was to demonstrate the use of robotic vehicles for deploying and autonomously reconfiguring seismic and acoustic sensor arrays with high (centimeter) accuracy to obtain enhancement of our capability to locate and characterize remote targets. The capability to accurately place sensors and then retrieve and reconfigure them allows sensors to be placed in phased arrays in an initial monitoring configuration and then to be reconfigured in an array tuned to the specific frequencies and directions of the selected target. This report reviews the findings and accomplishments achieved during this three-year project. This project successfully demonstrated autonomous deployment and retrieval of a payload package with an accuracy of a few centimeters using differential global positioning system (GPS) signals. It developed an autonomous, multisensor, temporally aligned, radio-frequency communication and signal processing capability, and an array optimization algorithm, which was implemented on a digital signal processor (DSP). Additionally, the project converted the existing single-threaded, monolithic robotic vehicle control code into a multi-threaded, modular control architecture that enhances the reuse of control code in future projects.

  7. Enhancing four-wave-mixing processes by nanowire arrays coupled to a gold film.

    PubMed

    Poutrina, Ekaterina; Ciracì, Cristian; Gauthier, Daniel J; Smith, David R

    2012-05-07

    We consider the process of four-wave mixing in an array of gold nanowires strongly coupled to a gold film. Using full-wave simulations, we perform a quantitative comparison of the four-wave mixing efficiency associated with a bare film and films with nanowire arrays. We find that the strongly localized surface plasmon resonances of the coupled nanowires provide an additional local field enhancement that, along with the delocalized surface plasmon of the film, produces an overall four-wave mixing efficiency enhancement of up to six orders of magnitude over that of the bare film. The enhancement occurs over a wide range of excitation angles. The film-coupled nanowire array is easily amenable to nanofabrication, and could find application as an ultra-compact component for integrated photonic and quantum optic systems.

  8. High Density Crossbar Arrays with Sub- 15 nm Single Cells via Liftoff Process Only

    NASA Astrophysics Data System (ADS)

    Khiat, Ali; Ayliffe, Peter; Prodromakis, Themistoklis

    2016-09-01

    Emerging nano-scale technologies are pushing the fabrication boundaries at their limits, for leveraging an even higher density of nano-devices towards reaching 4F2/cell footprint in 3D arrays. Here, we study the liftoff process limits to achieve extreme dense nanowires while ensuring preservation of thin film quality. The proposed method is optimized for attaining a multiple layer fabrication to reliably achieve 3D nano-device stacks of 32 × 32 nanowire arrays across 6-inch wafer, using electron beam lithography at 100 kV and polymethyl methacrylate (PMMA) resist at different thicknesses. The resist thickness and its geometric profile after development were identified to be the major limiting factors, and suggestions for addressing these issues are provided. Multiple layers were successfully achieved to fabricate arrays of 1 Ki cells that have sub- 15 nm nanowires distant by 28 nm across 6-inch wafer.

  9. High Density Crossbar Arrays with Sub- 15 nm Single Cells via Liftoff Process Only

    PubMed Central

    Khiat, Ali; Ayliffe, Peter; Prodromakis, Themistoklis

    2016-01-01

    Emerging nano-scale technologies are pushing the fabrication boundaries at their limits, for leveraging an even higher density of nano-devices towards reaching 4F2/cell footprint in 3D arrays. Here, we study the liftoff process limits to achieve extreme dense nanowires while ensuring preservation of thin film quality. The proposed method is optimized for attaining a multiple layer fabrication to reliably achieve 3D nano-device stacks of 32 × 32 nanowire arrays across 6-inch wafer, using electron beam lithography at 100 kV and polymethyl methacrylate (PMMA) resist at different thicknesses. The resist thickness and its geometric profile after development were identified to be the major limiting factors, and suggestions for addressing these issues are provided. Multiple layers were successfully achieved to fabricate arrays of 1 Ki cells that have sub- 15 nm nanowires distant by 28 nm across 6-inch wafer. PMID:27585643

  10. Effects of anodization process of aluminum oxide template fabrication on selective growth of Si nanowire arrays

    NASA Astrophysics Data System (ADS)

    Hoang Nguyen, Van; Tutashkonko, Sergii; Hoshi, Yusuke; Usami, Noritaka

    2015-08-01

    We report on effects of anodization process of anodic aluminum oxide (AAO) template on selective growth of Si nanowires using gas source molecular beam epitaxy. By switching off the anodization currents at several points, the structure of Si surface was altered, which was critical factor for the Si nanowire array growth. With reasonable switched-off point of anodization current at R of 10%, the selective growth of Si nanowire growth was favorable and 1-µm-long Si nanowire arrays were successfully grown. It was interesting that their structures were epitaxial structures; whereas, long anodization of AAO was found to be unfavorable for growth of Si nanowires due to anodization of Si surface. It caused the density of Si nanowire arrays to be modest and their structures were polycrystal structure.

  11. High-density through-wafer copper via array in insulating glass mold using reflow process

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Woo; Lee, Seung-Ki; Park, Jae-Hyoung

    2015-04-01

    A high-density through-wafer vertical copper via array in insulating glass interposer is demonstrated. The glass reflow and bottom-up filling copper electroplating process enables fabrication of a vertical through-wafer copper via array with high aspect ratio and high density. The minimum diameter of the copper vias and the gaps in between are 20 and 10 µm, respectively. Three failures among one hundred measurement points were detected within a 1 cm2 area of the via array, and the resistance of the 20-µm-diameter copper via was measured to be 153 ± 23 mΩ using the four-probe method. The optical transmittance and RF performance of the reflowed glass substrate were compared with those of bare glass. The reliability of the copper via in harsh environments was evaluated through thermal shock and pressure cooker tests.

  12. Sample processing for DNA chip array-based analysis of enterohemorrhagic Escherichia coli (EHEC).

    PubMed

    Basselet, Pascal; Wegrzyn, Grzegorz; Enfors, Sven-Olof; Gabig-Ciminska, Magdalena

    2008-10-13

    Exploitation of DNA-based analyses of microbial pathogens, and especially simultaneous typing of several virulence-related genes in bacteria is becoming an important objective of public health these days. A procedure for sample processing for a confirmative analysis of enterohemorrhagic Escherichia coli (EHEC) on a single colony with DNA chip array was developed and is reported here. The protocol includes application of fragmented genomic DNA from ultrasonicated colonies. The sample processing comprises first 2.5 min of ultrasonic treatment, DNA extraction (2x), and afterwards additional 5 min ultrasonication. Thus, the total sample preparation time for a confirmative analysis of EHEC is nearly 10 min. Additionally, bioinformatic revisions were performed in order to design PCR primers and array probes specific to most conservative regions of the EHEC-associated genes. Six strains with distinct pathogenic properties were selected for this study. At last, the EHEC chip array for a parallel and simultaneous detection of genes etpC-stx1-stx2-eae was designed and examined. This should permit to sense all currently accessible variants of the selected sequences in EHEC types and subtypes. In order to implement the DNA chip array-based analysis for direct EHEC detection the sample processing was established in course of this work. However, this sample preparation mode may also be applied to other types of EHEC DNA-based sensing systems.

  13. High density processing electronics for superconducting tunnel junction x-ray detector arrays

    NASA Astrophysics Data System (ADS)

    Warburton, W. K.; Harris, J. T.; Friedrich, S.

    2015-06-01

    Superconducting tunnel junctions (STJs) are excellent soft x-ray (100-2000 eV) detectors, particularly for synchrotron applications, because of their ability to obtain energy resolutions below 10 eV at count rates approaching 10 kcps. In order to achieve useful solid detection angles with these very small detectors, they are typically deployed in large arrays - currently with 100+ elements, but with 1000 elements being contemplated. In this paper we review a 5-year effort to develop compact, computer controlled low-noise processing electronics for STJ detector arrays, focusing on the major issues encountered and our solutions to them. Of particular interest are our preamplifier design, which can set the STJ operating points under computer control and achieve 2.7 eV energy resolution; our low noise power supply, which produces only 2 nV/√Hz noise at the preamplifier's critical cascode node; our digital processing card that digitizes and digitally processes 32 channels; and an STJ I-V curve scanning algorithm that computes noise as a function of offset voltage, allowing an optimum operating point to be easily selected. With 32 preamplifiers laid out on a custom 3U EuroCard, and the 32 channel digital card in a 3U PXI card format, electronics for a 128 channel array occupy only two small chassis, each the size of a National Instruments 5-slot PXI crate, and allow full array control with simple extensions of existing beam line data collection packages.

  14. Process optimization of Si:As indium bumped focal plane arrays

    NASA Astrophysics Data System (ADS)

    Benninghoven, K. A.

    1992-07-01

    In a particular application, a Si:As focal plane array may experience many thermal cycles from ambient down to its operating temperature (10 Kelvin) at a very rapid cooldown rate. Aerojet Electronic Systems Division's task, under company funds, was to consistently produce focal plane arrays that could reliably survive this kind of thermal cycling with no degradation in performance or mechanical damage. Of utmost importance in the verification of the focal plane array reliability is the assurance that the test configuration reflects flight configuration in material, interfaces, and process procedures. Using flight-like hardware, process procedures were developed to optimize hybridization parameters (the means of bonding the indium bumped readout electronics to the detector array) with bonding strength and electrical resistance selected as the figures of merit. When the materials, processes and assembly procedures were developed, a final verification was conducted which consisted of rapidly thermal cycling two flight-like hybrids. The hybrids successfully withstood more than 800 cycles from 60 Kelvin to 10 Kelvin and over 20 cycles from 300 Kelvin to 60 Kelvin with no degradation in performance or mechanical integrity.

  15. Microphone array signal processing with application in three-dimensional spatial hearing

    NASA Astrophysics Data System (ADS)

    Bai, Mingsian R.; Lin, Chenpang

    2005-04-01

    Microphone arrays are known to enhance the directionality and signal-to-noise ratio (SNR) over single-channel sensors. This is considered beneficial in many applications such as video-conferencing systems and hearing aids. However, this advantage comes at the price of the sensation of spatial hearing. The spatial cues due to diffractions of the head and torso are lost if the array is not fitted in the ears. In this paper we present a system that incorporates binaural hearing synthesis into array signal processing, in an attempt to recover the three-dimensional sound image that a human listener would naturally perceive. In the system, the superdirective beamformer is exploited to estimate the direction of arrival (DOA) of the incoming sound. The spatial sound image is restored by steering the beam to the direction found in the DOA session and filtering the array output with the corresponding Head Related Transfer Functions (HRTF). The algorithms have been implemented in real-time fashion using a digital signal processor. Objective and subjective experiments were performed to validate the proposed system. The experimental results showed that the accurate localization of the sound source is achievable using the array system. .

  16. A novel method using adaptive hidden semi-Markov model for multi-sensor monitoring equipment health prognosis

    NASA Astrophysics Data System (ADS)

    Liu, Qinming; Dong, Ming; Lv, Wenyuan; Geng, Xiuli; Li, Yupeng

    2015-12-01

    Health prognosis for equipment is considered as a key process of the condition-based maintenance strategy. This paper presents an integrated framework for multi-sensor equipment diagnosis and prognosis based on adaptive hidden semi-Markov model (AHSMM). Unlike hidden semi-Markov model (HSMM), the basic algorithms in an AHSMM are first modified in order for decreasing computation and space complexity. Then, the maximum likelihood linear regression transformations method is used to train the output and duration distributions to re-estimate all unknown parameters. The AHSMM is used to identify the hidden degradation state and obtain the transition probabilities among health states and durations. Finally, through the proposed hazard rate equations, one can predict the useful remaining life of equipment with multi-sensor information. Our main results are verified in real world applications: monitoring hydraulic pumps from Caterpillar Inc. The results show that the proposed methods are more effective for multi-sensor monitoring equipment health prognosis.

  17. High resolution beamforming on large aperture vertical line arrays: Processing synthetic data

    NASA Astrophysics Data System (ADS)

    Tran, Jean-Marie Q.; Hodgkiss, William S.

    1990-09-01

    This technical memorandum studies the beamforming of large aperture line arrays deployed vertically in the water column. The work concentrates on the use of high resolution techniques. Two processing strategies are envisioned: (1) full aperture coherent processing which offers in theory the best processing gain; and (2) subaperture processing which consists in extracting subapertures from the array and recombining the angular spectra estimated from these subarrays. The conventional beamformer, the minimum variance distortionless response (MVDR) processor, the multiple signal classification (MUSIC) algorithm and the minimum norm method are used in this study. To validate the various processing techniques, the ATLAS normal mode program is used to generate synthetic data which constitute a realistic signals environment. A deep-water, range-independent sound velocity profile environment, characteristic of the North-East Pacific, is being studied for two different 128 sensor arrays: a very long one cut for 30 Hz and operating at 20 Hz; and a shorter one cut for 107 Hz and operating at 100 Hz. The simulated sound source is 5 m deep. The full aperture and subaperture processing are being implemented with curved and plane wavefront replica vectors. The beamforming results are examined and compared to the ray-theory results produced by the generic sonar model.

  18. Hybrid Arrays for Chemical Sensing

    NASA Astrophysics Data System (ADS)

    Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Johnson, Kevin J.; Minor, Christian P.

    In recent years, multisensory approaches to environment monitoring for chemical detection as well as other forms of situational awareness have become increasingly popular. A hybrid sensor is a multimodal system that incorporates several sensing elements and thus produces data that are multivariate in nature and may be significantly increased in complexity compared to data provided by single-sensor systems. Though a hybrid sensor is itself an array, hybrid sensors are often organized into more complex sensing systems through an assortment of network topologies. Part of the reason for the shift to hybrid sensors is due to advancements in sensor technology and computational power available for processing larger amounts of data. There is also ample evidence to support the claim that a multivariate analytical approach is generally superior to univariate measurements because it provides additional redundant and complementary information (Hall, D. L.; Linas, J., Eds., Handbook of Multisensor Data Fusion, CRC, Boca Raton, FL, 2001). However, the benefits of a multisensory approach are not automatically achieved. Interpretation of data from hybrid arrays of sensors requires the analyst to develop an application-specific methodology to optimally fuse the disparate sources of data generated by the hybrid array into useful information characterizing the sample or environment being observed. Consequently, multivariate data analysis techniques such as those employed in the field of chemometrics have become more important in analyzing sensor array data. Depending on the nature of the acquired data, a number of chemometric algorithms may prove useful in the analysis and interpretation of data from hybrid sensor arrays. It is important to note, however, that the challenges posed by the analysis of hybrid sensor array data are not unique to the field of chemical sensing. Applications in electrical and process engineering, remote sensing, medicine, and of course, artificial

  19. Enhancement of Data Analysis Through Multisensor Data Fusion Technology

    USDA-ARS?s Scientific Manuscript database

    Multi-sensor data fusion is an emerging technology that fuses data from multiple sensors in order to make a more accurate estimation of the environment through measurement and detection. Applications of multi-sensor data fusion cross a wide spectrum in military and civilian areas. With the rapid e...

  20. Multi-Sensor Towed Array Detection System (MTADS)

    DTIC Science & Technology

    1999-09-01

    Laboratory OEW Ordnance Explosives Wastes OST Oglala Sioux Tribe LIST OF ACRONYMS (continued) viii PC personal computer PRC Personnel Readiness Center QA...training range for the Air National Guard. Since 1960, portions of the land have been returned to the Oglala Sioux Tribe (OST) in a step- wise fashion

  1. Extension of DAMAS Phased Array Processing for Spatial Coherence Determination (DAMAS-C)

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    2006-01-01

    The present study reports a new development of the DAMAS microphone phased array processing methodology that allows the determination and separation of coherent and incoherent noise source distributions. In 2004, a Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) was developed which decoupled the array design and processing influence from the noise being measured, using a simple and robust algorithm. In 2005, three-dimensional applications of DAMAS were examined. DAMAS has been shown to render an unambiguous quantitative determination of acoustic source position and strength. However, an underlying premise of DAMAS, as well as that of classical array beamforming methodology, is that the noise regions under study are distributions of statistically independent sources. The present development, called DAMAS-C, extends the basic approach to include coherence definition between noise sources. The solutions incorporate cross-beamforming array measurements over the survey region. While the resulting inverse problem can be large and the iteration solution computationally demanding, it solves problems no other technique can approach. DAMAS-C is validated using noise source simulations and is applied to airframe flap noise test results.

  2. Direct Growth of Crystalline Tungsten Oxide Nanorod Arrays by a Hydrothermal Process and Their Electrochromic Properties

    NASA Astrophysics Data System (ADS)

    Lu, Chih-Hao; Hon, Min Hsiung; Leu, Ing-Chi

    2017-04-01

    Transparent crystalline tungsten oxide nanorod arrays for use as an electrochromic layer have been directly prepared on fluorine-doped tin oxide-coated glass via a facile tungsten film-assisted hydrothermal process using aqueous tungsten hexachloride solution. X-ray diffraction analysis and field-emission scanning electron microscopy were used to characterize the phase and morphology of the grown nanostructures. Arrays of tungsten oxide nanorods with diameter of ˜22 nm and length of ˜240 nm were obtained at 200°C after 8 h of hydrothermal reaction. We propose a growth mechanism for the deposition of the monoclinic tungsten oxide phase in the hydrothermal environment. The tungsten film was first oxidized to tungsten oxide to provide seed sites for crystal growth and address the poor connection between the growing tungsten oxide and substrate. Aligned tungsten oxide nanorod arrays can be grown by a W thin film-assisted heterogeneous nucleation process with NaCl as a structure-directing agent. The fabricated electrochromic device demonstrated optical modulation (coloration/bleaching) at 632.8 nm of ˜41.2% after applying a low voltage of 0.1 V for 10 s, indicating the potential of such nanorod array films for use in energy-saving smart windows.

  3. Direct Growth of Crystalline Tungsten Oxide Nanorod Arrays by a Hydrothermal Process and Their Electrochromic Properties

    NASA Astrophysics Data System (ADS)

    Lu, Chih-Hao; Hon, Min Hsiung; Leu, Ing-Chi

    2016-12-01

    Transparent crystalline tungsten oxide nanorod arrays for use as an electrochromic layer have been directly prepared on fluorine-doped tin oxide-coated glass via a facile tungsten film-assisted hydrothermal process using aqueous tungsten hexachloride solution. X-ray diffraction analysis and field-emission scanning electron microscopy were used to characterize the phase and morphology of the grown nanostructures. Arrays of tungsten oxide nanorods with diameter of ˜22 nm and length of ˜240 nm were obtained at 200°C after 8 h of hydrothermal reaction. We propose a growth mechanism for the deposition of the monoclinic tungsten oxide phase in the hydrothermal environment. The tungsten film was first oxidized to tungsten oxide to provide seed sites for crystal growth and address the poor connection between the growing tungsten oxide and substrate. Aligned tungsten oxide nanorod arrays can be grown by a W thin film-assisted heterogeneous nucleation process with NaCl as a structure-directing agent. The fabricated electrochromic device demonstrated optical modulation (coloration/bleaching) at 632.8 nm of ˜41.2% after applying a low voltage of 0.1 V for 10 s, indicating the potential of such nanorod array films for use in energy-saving smart windows.

  4. Flexible All-organic, All-solution Processed Thin Film Transistor Array with Ultrashort Channel

    PubMed Central

    Xu, Wei; Hu, Zhanhao; Liu, Huimin; Lan, Linfeng; Peng, Junbiao; Wang, Jian; Cao, Yong

    2016-01-01

    Shrinking the device dimension has long been the pursuit of the semiconductor industry to increase the device density and operation speed. In the application of thin film transistors (TFTs), all-organic TFT arrays made by all-solution process are desired for low cost and flexible electronics. One of the greatest challenges is how to achieve ultrashort channel through a cost-effective method. In our study, ultrashort-channel devices are demonstrated by direct inkjet printing conducting polymer as source/drain and gate electrodes without any complicated substrate’s pre-patterning process. By modifying the substrate’s wettability, the conducting polymer’s contact line is pinned during drying process which makes the channel length well-controlled. An organic TFT array of 200 devices with 2 μm channel length is fabricated on flexible substrate through all-solution process. The simple and scalable process to fabricate high resolution organic transistor array offers a low cost approach in the development of flexible and wearable electronics. PMID:27378163

  5. Flexible All-organic, All-solution Processed Thin Film Transistor Array with Ultrashort Channel

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Hu, Zhanhao; Liu, Huimin; Lan, Linfeng; Peng, Junbiao; Wang, Jian; Cao, Yong

    2016-07-01

    Shrinking the device dimension has long been the pursuit of the semiconductor industry to increase the device density and operation speed. In the application of thin film transistors (TFTs), all-organic TFT arrays made by all-solution process are desired for low cost and flexible electronics. One of the greatest challenges is how to achieve ultrashort channel through a cost-effective method. In our study, ultrashort-channel devices are demonstrated by direct inkjet printing conducting polymer as source/drain and gate electrodes without any complicated substrate’s pre-patterning process. By modifying the substrate’s wettability, the conducting polymer’s contact line is pinned during drying process which makes the channel length well-controlled. An organic TFT array of 200 devices with 2 μm channel length is fabricated on flexible substrate through all-solution process. The simple and scalable process to fabricate high resolution organic transistor array offers a low cost approach in the development of flexible and wearable electronics.

  6. Reliability measurement during software development. [for a multisensor tracking system

    NASA Technical Reports Server (NTRS)

    Hecht, H.; Sturm, W. A.; Trattner, S.

    1977-01-01

    During the development of data base software for a multi-sensor tracking system, reliability was measured. The failure ratio and failure rate were found to be consistent measures. Trend lines were established from these measurements that provided good visualization of the progress on the job as a whole as well as on individual modules. Over one-half of the observed failures were due to factors associated with the individual run submission rather than with the code proper. Possible application of these findings for line management, project managers, functional management, and regulatory agencies is discussed. Steps for simplifying the measurement process and for use of these data in predicting operational software reliability are outlined.

  7. A survey of multi-sensor data fusion systems

    NASA Astrophysics Data System (ADS)

    Linn, R. J.; Hall, D. L.; Llinas, J.

    1991-08-01

    Multisensor data fusion integrates data from multiple sensors (and types of sensors) to perform inferences which are more accurate and specific than those from processing single-sensor data. Levels of inference range from target detection and identification to higher level situation assessment and threat assessment. This paper provides a survey of more than 50 data fusion systems and summarizes their application, development environment, system status and key techniques. The techniques are mapped to a taxonomy previously developed by Hall and Linn (1990); these include positional fusion techniques, such as association and estimation, and identity fusion methods, including statistical methods, nonparametric methods, and cognitive techniques (e.g. templating, knowledge-based systems, and fuzzy reasoning). An assessment of the state of fusion system development is provided.

  8. Multi-sensor data fusion framework for CNC machining monitoring

    NASA Astrophysics Data System (ADS)

    Duro, João A.; Padget, Julian A.; Bowen, Chris R.; Kim, H. Alicia; Nassehi, Aydin

    2016-01-01

    Reliable machining monitoring systems are essential for lowering production time and manufacturing costs. Existing expensive monitoring systems focus on prevention/detection of tool malfunctions and provide information for process optimisation by force measurement. An alternative and cost-effective approach is monitoring acoustic emissions (AEs) from machining operations by acting as a robust proxy. The limitations of AEs include high sensitivity to sensor position and cutting parameters. In this paper, a novel multi-sensor data fusion framework is proposed to enable identification of the best sensor locations for monitoring cutting operations, identifying sensors that provide the best signal, and derivation of signals with an enhanced periodic component. Our experimental results reveal that by utilising the framework, and using only three sensors, signal interpretation improves substantially and the monitoring system reliability is enhanced for a wide range of machining parameters. The framework provides a route to overcoming the major limitations of AE based monitoring.

  9. A Passive Wireless Multi-Sensor SAW Technology Device and System Perspectives

    PubMed Central

    Malocha, Donald C.; Gallagher, Mark; Fisher, Brian; Humphries, James; Gallagher, Daniel; Kozlovski, Nikolai

    2013-01-01

    This paper will discuss a SAW passive, wireless multi-sensor system under development by our group for the past several years. The device focus is on orthogonal frequency coded (OFC) SAW sensors, which use both frequency diversity and pulse position reflectors to encode the device ID and will be briefly contrasted to other embodiments. A synchronous correlator transceiver is used for the hardware and post processing and correlation techniques of the received signal to extract the sensor information will be presented. Critical device and system parameters addressed include encoding, operational range, SAW device parameters, post-processing, and antenna-SAW device integration. A fully developed 915 MHz OFC SAW multi-sensor system is used to show experimental results. The system is based on a software radio approach that provides great flexibility for future enhancements and diverse sensor applications. Several different sensor types using the OFC SAW platform are shown. PMID:23666124

  10. A passive wireless multi-sensor SAW technology device and system perspectives.

    PubMed

    Malocha, Donald C; Gallagher, Mark; Fisher, Brian; Humphries, James; Gallagher, Daniel; Kozlovski, Nikolai

    2013-05-10

    This paper will discuss a SAW passive, wireless multi-sensor system under development by our group for the past several years. The device focus is on orthogonal frequency coded (OFC) SAW sensors, which use both frequency diversity and pulse position reflectors to encode the device ID and will be briefly contrasted to other embodiments. A synchronous correlator transceiver is used for the hardware and post processing and correlation techniques of the received signal to extract the sensor information will be presented. Critical device and system parameters addressed include encoding, operational range, SAW device parameters, post-processing, and antenna-SAW device integration. A fully developed 915 MHz OFC SAW multi-sensor system is used to show experimental results. The system is based on a software radio approach that provides great flexibility for future enhancements and diverse sensor applications. Several different sensor types using the OFC SAW platform are shown.

  11. NeuroSeek dual-color image processing infrared focal plane array

    NASA Astrophysics Data System (ADS)

    McCarley, Paul L.; Massie, Mark A.; Baxter, Christopher R.; Huynh, Buu L.

    1998-09-01

    Several technologies have been developed in recent years to advance the state of the art of IR sensor systems including dual color affordable focal planes, on-focal plane array biologically inspired image and signal processing techniques and spectral sensing techniques. Pacific Advanced Technology (PAT) and the Air Force Research Lab Munitions Directorate have developed a system which incorporates the best of these capabilities into a single device. The 'NeuroSeek' device integrates these technologies into an IR focal plane array (FPA) which combines multicolor Midwave IR/Longwave IR radiometric response with on-focal plane 'smart' neuromorphic analog image processing. The readout and processing integrated circuit very large scale integration chip which was developed under this effort will be hybridized to a dual color detector array to produce the NeuroSeek FPA, which will have the capability to fuse multiple pixel-based sensor inputs directly on the focal plane. Great advantages are afforded by application of massively parallel processing algorithms to image data in the analog domain; the high speed and low power consumption of this device mimic operations performed in the human retina.

  12. Low frequency ultrasonic array imaging using signal post-processing for concrete material

    NASA Astrophysics Data System (ADS)

    Ozawa, Akio; Izumi, Hideki; Nakahata, Kazuyuki; Ohira, Katsumi; Ogawa, Kenzo

    2017-02-01

    The use of ultrasonic arrays to conduct nondestructive evaluation has significantly increased in recent years. A post-processing beam-forming technique that utilizes a complete set of signals of all combinations of transmission and reception el-ements was proposed as an array imaging technique. In this study, a delay-and-sum beam reconstruction method utilizing post-processing was applied to the imaging of internal voids and reinforced steel bars in concrete material. Due to the high attenuation of the ultrasonic wave in concrete, it is necessary to use an ultrasonic wave as the incident wave at low frequencies and high in-tensities. In this study, an array transducer with a total of 16 elements was designed on the basis of a multigaussian beam model. The center frequency of the transducer was 50 kHz, and low frequency imaging was achieved by performing computations using a graphics processing unit accelerators in the post-processing beam formation. The results indicated that the shapes of through holes and steel bars in a concrete specimen with 700 mm height were reconstructed with high resolution.

  13. Fully Solution-Processed Flexible Organic Thin Film Transistor Arrays with High Mobility and Exceptional Uniformity

    PubMed Central

    Fukuda, Kenjiro; Takeda, Yasunori; Mizukami, Makoto; Kumaki, Daisuke; Tokito, Shizuo

    2014-01-01

    Printing fully solution-processed organic electronic devices may potentially revolutionize production of flexible electronics for various applications. However, difficulties in forming thin, flat, uniform films through printing techniques have been responsible for poor device performance and low yields. Here, we report on fully solution-processed organic thin-film transistor (TFT) arrays with greatly improved performance and yields, achieved by layering solution-processable materials such as silver nanoparticle inks, organic semiconductors, and insulating polymers on thin plastic films. A treatment layer improves carrier injection between the source/drain electrodes and the semiconducting layer and dramatically reduces contact resistance. Furthermore, an organic semiconductor with large-crystal grains results in TFT devices with shorter channel lengths and higher field-effect mobilities. We obtained mobilities of over 1.2 cm2 V−1 s−1 in TFT devices with channel lengths shorter than 20 μm. By combining these fabrication techniques, we built highly uniform organic TFT arrays with average mobility levels as high as 0.80 cm2 V−1 s−1 and ideal threshold voltages of 0 V. These results represent major progress in the fabrication of fully solution-processed organic TFT device arrays. PMID:24492785

  14. Fabrication of hybrid nanostructured arrays using a PDMS/PDMS replication process.

    PubMed

    Hassanin, H; Mohammadkhani, A; Jiang, K

    2012-10-21

    In the study, a novel and low cost nanofabrication process is proposed for producing hybrid polydimethylsiloxane (PDMS) nanostructured arrays. The proposed process involves monolayer self-assembly of polystyrene (PS) spheres, PDMS nanoreplication, thin film coating, and PDMS to PDMS (PDMS/PDMS) replication. A self-assembled monolayer of PS spheres is used as the first template. Second, a PDMS template is achieved by replica moulding. Third, the PDMS template is coated with a platinum or gold layer. Finally, a PDMS nanostructured array is developed by casting PDMS slurry on top of the coated PDMS. The cured PDMS is peeled off and used as a replica surface. In this study, the influences of the coating on the PDMS topography, contact angle of the PDMS slurry and the peeling off ability are discussed in detail. From experimental evaluation, a thickness of at least 20 nm gold layer or 40 nm platinum layer on the surface of the PDMS template improves the contact angle and eases peeling off. The coated PDMS surface is successfully used as a template to achieve the replica with a uniform array via PDMS/PDMS replication process. Both the PDMS template and the replica are free of defects and also undistorted after demoulding with a highly ordered hexagonal arrangement. In addition, the geometry of the nanostructured PDMS can be controlled by changing the thickness of the deposited layer. The simplicity and the controllability of the process show great promise as a robust nanoreplication method for functional applications.

  15. Process development for automated solar cell and module production. Task 4: Automated array assembly

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A process sequence which can be used in conjunction with automated equipment for the mass production of solar cell modules for terrestrial use was developed. The process sequence was then critically analyzed from a technical and economic standpoint to determine the technological readiness of certain process steps for implementation. The steps receiving analysis were: back contact metallization, automated cell array layup/interconnect, and module edge sealing. For automated layup/interconnect, both hard automation and programmable automation (using an industrial robot) were studied. The programmable automation system was then selected for actual hardware development.

  16. Implementation of a Digital Signal Processing Subsystem for a Long Wavelength Array Station

    NASA Technical Reports Server (NTRS)

    Soriano, Melissa; Navarro, Robert; D'Addario, Larry; Sigman, Elliott; Wang, Douglas

    2011-01-01

    This paper describes the implementation of a Digital Signal Processing (DP) subsystem for a single Long Wavelength Array (LWA) station.12 The LWA is a radio telescope that will consist of many phased array stations. Each LWA station consists of 256 pairs of dipole-like antennas operating over the 10-88 MHz frequency range. The Digital Signal Processing subsystem digitizes up to 260 dual-polarization signals at 196 MHz from the LWA Analog Receiver, adjusts the delay and amplitude of each signal, and forms four independent beams. Coarse delay is implemented using a first-in-first-out buffer and fine delay is implemented using a finite impulse response filter. Amplitude adjustment and polarization corrections are implemented using a 2x2 matrix multiplication

  17. Wind speed and direction measurement based on arc ultrasonic sensor array signal processing algorithm.

    PubMed

    Li, Xinbo; Sun, Haixin; Gao, Wei; Shi, Yaowu; Liu, Guojun; Wu, Yue

    2016-11-01

    This article investigates a kind of method to measure the wind speed and the wind direction, which is based on arc ultrasonic sensor array and combined with array signal processing algorithm. In the proposed method, a new arc ultrasonic array structure is introduced and the array manifold is derived firstly. On this basis, the measurement of the wind speed and the wind direction is analyzed and discussed by means of the basic idea of the classic MUSIC (Multiple Signal Classification) algorithm, which achieves the measurements of the 360° wind direction with resolution of 1° and 0-60m/s wind speed with resolution of 0.1m/s. The implementation of the proposed method is elaborated through the theoretical derivation and corresponding discussion. Besides, the simulation experiments are presented to show the feasibility of the proposed method. The theoretical analysis and simulation results indicate that the proposed method has superiority on anti-noise performance and improves the wind measurement accuracy.

  18. Subspace Dimensionality: A Tool for Automated QC in Seismic Array Processing

    NASA Astrophysics Data System (ADS)

    Rowe, C. A.; Stead, R. J.; Begnaud, M. L.

    2013-12-01

    Because of the great resolving power of seismic arrays, the application of automated processing to array data is critically important in treaty verification work. A significant problem in array analysis is the inclusion of bad sensor channels in the beamforming process. We are testing an approach to automated, on-the-fly quality control (QC) to aid in the identification of poorly performing sensor channels prior to beam-forming in routine event detection or location processing. The idea stems from methods used for large computer servers, when monitoring traffic at enormous numbers of nodes is impractical on a node-by node basis, so the dimensionality of the node traffic is instead monitoried for anomalies that could represent malware, cyber-attacks or other problems. The technique relies upon the use of subspace dimensionality or principal components of the overall system traffic. The subspace technique is not new to seismology, but its most common application has been limited to comparing waveforms to an a priori collection of templates for detecting highly similar events in a swarm or seismic cluster. In the established template application, a detector functions in a manner analogous to waveform cross-correlation, applying a statistical test to assess the similarity of the incoming data stream to known templates for events of interest. In our approach, we seek not to detect matching signals, but instead, we examine the signal subspace dimensionality in much the same way that the method addresses node traffic anomalies in large computer systems. Signal anomalies recorded on seismic arrays affect the dimensional structure of the array-wide time-series. We have shown previously that this observation is useful in identifying real seismic events, either by looking at the raw signal or derivatives thereof (entropy, kurtosis), but here we explore the effects of malfunctioning channels on the dimension of the data and its derivatives, and how to leverage this effect for

  19. The Acquisition of Development of Advanced Processing Techniques for CCD Arrays.

    DTIC Science & Technology

    1981-01-01

    pressure oxidation ( HIPOX ) techniques as a viable alternative to standard (atmospheric pressure) oxidation techniques in our buried channel CCD process. If...work performed may be summarized as follows: (1) Modelling of high pressure oxidation and anneal cycles. Subsitution of the new HIPOX cycles in the...NANP L I I "I lii-..D -- I The Acquisition of Develoment of Advanced ProcessinR Techniques for CCD Arrays ca- C-., Prepared by Bell-Northern Research

  20. Lightweight solar array blanket tooling, laser welding and cover process technology

    NASA Technical Reports Server (NTRS)

    Dillard, P. A.

    1983-01-01

    A two phase technology investigation was performed to demonstrate effective methods for integrating 50 micrometer thin solar cells into ultralightweight module designs. During the first phase, innovative tooling was developed which allows lightweight blankets to be fabricated in a manufacturing environment with acceptable yields. During the second phase, the tooling was improved and the feasibility of laser processing of lightweight arrays was confirmed. The development of the cell/interconnect registration tool and interconnect bonding by laser welding is described.

  1. Portable nuclear material detector and process

    DOEpatents

    Hofstetter, Kenneth J; Fulghum, Charles K; Harpring, Lawrence J; Huffman, Russell K; Varble, Donald L

    2008-04-01

    A portable, hand held, multi-sensor radiation detector is disclosed. The detection apparatus has a plurality of spaced sensor locations which are contained within a flexible housing. The detection apparatus, when suspended from an elevation, will readily assume a substantially straight, vertical orientation and may be used to monitor radiation levels from shipping containers. The flexible detection array can also assume a variety of other orientations to facilitate any unique container shapes or to conform to various physical requirements with respect to deployment of the detection array. The output of each sensor within the array is processed by at least one CPU which provides information in a usable form to a user interface. The user interface is used to provide the power requirements and operating instructions to the operational components within the detection array.

  2. Portable nuclear material detector and process

    DOEpatents

    Hofstetter, Kenneth J [Aiken, SC; Fulghum, Charles K [Aiken, SC; Harpring, Lawrence J [North Augusta, SC; Huffman, Russell K [Augusta, GA; Varble, Donald L [Evans, GA

    2008-04-01

    A portable, hand held, multi-sensor radiation detector is disclosed. The detection apparatus has a plurality of spaced sensor locations which are contained within a flexible housing. The detection apparatus, when suspended from an elevation, will readily assume a substantially straight, vertical orientation and may be used to monitor radiation levels from shipping containers. The flexible detection array can also assume a variety of other orientations to facilitate any unique container shapes or to conform to various physical requirements with respect to deployment of the detection array. The output of each sensor within the array is processed by at least one CPU which provides information in a usable form to a user interface. The user interface is used to provide the power requirements and operating instructions to the operational components within the detection array.

  3. Monitoring and evaluation of alcoholic fermentation processes using a chemocapacitor sensor array.

    PubMed

    Oikonomou, Petros; Raptis, Ioannis; Sanopoulou, Merope

    2014-09-02

    The alcoholic fermentation of Savatiano must variety was initiated under laboratory conditions and monitored daily with a gas sensor array without any pre-treatment steps. The sensor array consisted of eight interdigitated chemocapacitors (IDCs) coated with specific polymers. Two batches of fermented must were tested and also subjected daily to standard chemical analysis. The chemical composition of the two fermenting musts differed from day one of laboratory monitoring (due to different storage conditions of the musts) and due to a deliberate increase of the acetic acid content of one of the musts, during the course of the process, in an effort to spoil the fermenting medium. Sensor array responses to the headspace of the fermenting medium were compared with those obtained either for pure or contaminated samples with controlled concentrations of standard ethanol solutions of impurities. Results of data processing with Principal Component Analysis (PCA), demonstrate that this sensing system could discriminate between a normal and a potential spoiled grape must fermentation process, so this gas sensing system could be potentially applied during wine production as an auxiliary qualitative control instrument.

  4. Monitoring and Evaluation of Alcoholic Fermentation Processes Using a Chemocapacitor Sensor Array

    PubMed Central

    Oikonomou, Petros; Raptis, Ioannis; Sanopoulou, Merope

    2014-01-01

    The alcoholic fermentation of Savatiano must variety was initiated under laboratory conditions and monitored daily with a gas sensor array without any pre-treatment steps. The sensor array consisted of eight interdigitated chemocapacitors (IDCs) coated with specific polymers. Two batches of fermented must were tested and also subjected daily to standard chemical analysis. The chemical composition of the two fermenting musts differed from day one of laboratory monitoring (due to different storage conditions of the musts) and due to a deliberate increase of the acetic acid content of one of the musts, during the course of the process, in an effort to spoil the fermenting medium. Sensor array responses to the headspace of the fermenting medium were compared with those obtained either for pure or contaminated samples with controlled concentrations of standard ethanol solutions of impurities. Results of data processing with Principal Component Analysis (PCA), demonstrate that this sensing system could discriminate between a normal and a potential spoiled grape must fermentation process, so this gas sensing system could be potentially applied during wine production as an auxiliary qualitative control instrument. PMID:25184490

  5. InGaAs/InP PIN photodetector arrays made by MOCVD based zinc diffusion processes

    NASA Astrophysics Data System (ADS)

    Islam, Mohammad; Feng, J. Y.; Berkovich, Andrew; Abshire, Pamela; Barrows, Geoffrey; Choa, Fow-Sen

    2016-05-01

    InGaAs based long-wavelength near infrared detector arrays are very important for high dynamic range imaging operations seamlessly from daylight environments to dark environments. These detector devices are usually made by open-hole diffusion technique which has the advantage of lower leakage current and higher reliability. The diffusion process is usually done in a sealed quartz ampoule with dopant compounds like ZnP2, ZnAs3, CdP2 etc. side by side with semiconductor samples. The ampoule needs to be prepared and sealing process needs to be done in very clean environment and each time can have variations. In this work we demonstrated using MOCVD growth chamber to perform the diffusion process. The advantages of such a process are that the tool is constantly kept in ultra clean environment and can reproducibly provide clean processes without introducing unexpected defects. We can independently control the temperature and flow rate of the dopant - they are not linked as in the ampoule diffusion case. The process can be done on full wafers with good uniformity through substrate rotation, which is good for large detector array fabrications. We have fabricated different types of InGaAs/InP detector arrays using dimethyl zinc as the dopant source and PH3 or AsH3 for surface protection. Pre-studies of Zn-diffusion profiles in InGaAs and InP at different temperatures, flow rates, diffusion times and followed annealing times were conducted to obtain good control of the process. Grown samples were measured by C-V profilometer to evaluate the diffusion depth and doping concentration. The dependence of the diffusion profile with temperature, dopant partial pressures, and annealing temperature and time and some of the fabricated device characteristics are reported.

  6. Development of subminiature multi-sensor hot-wire probes

    NASA Technical Reports Server (NTRS)

    Westphal, Russell V.; Ligrani, Phillip M.; Lemos, Fred R.

    1988-01-01

    Limitations on the spatial resolution of multisensor hot wire probes have precluded accurate measurements of Reynolds stresses very near solid surfaces in wind tunnels and in many practical aerodynamic flows. The fabrication, calibration and qualification testing of very small single horizontal and X-array hot-wire probes which are intended to be used near solid boundaries in turbulent flows where length scales are particularly small, is described. Details of the sensor fabrication procedure are reported, along with information needed to successfully operate the probes. As compared with conventional probes, manufacture of the subminiature probes is more complex, requiring special equipment and careful handling. The subminiature probes tested were more fragile and shorter lived than conventional probes; they obeyed the same calibration laws but with slightly larger experimental uncertainty. In spite of these disadvantages, measurements of mean statistical quantities and spectra demonstrate the ability of the subminiature sensors to provide the measurements in the near wall region of turbulent boundary layers that are more accurate than conventional sized probes.

  7. Regional Mapping of Plantation Extent Using Multisensor Imagery

    NASA Astrophysics Data System (ADS)

    Torbick, N.; Ledoux, L.; Hagen, S.; Salas, W.

    2016-12-01

    Industrial forest plantations are expanding rapidly across the tropics and monitoring extent is critical for understanding environmental and socioeconomic impacts. In this study, new, multisensor imagery were evaluated and integrated to extract the strengths of each sensor for mapping plantation extent at regional scales. Three distinctly different landscapes with multiple plantation types were chosen to consider scalability and transferability. These were Tanintharyi, Myanmar, West Kalimantan, Indonesia, and southern Ghana. Landsat-8 Operational Land Imager (OLI), Phased Array L-band Synthetic Aperture Radar-2 (PALSAR-2), and Sentinel-1A images were fused within a Classification and Regression Tree (CART) framework using random forest and high-resolution surveys. Multi-criteria evaluations showed both L-and C-band gamma nought γ° backscatter decibel (dB), Landsat reflectance ρλ, and texture indices were useful for distinguishing oil palm and rubber plantations from other land types. The classification approach identified 750,822 ha or 23% of the Taninathryi, Myanmar, and 216,086 ha or 25% of western West Kalimantan as plantation with very high cross validation accuracy. The mapping approach was scalable and transferred well across the different geographies and plantation types. As archives for Sentinel-1, Landsat-8, and PALSAR-2 continue to grow, mapping plantation extent and dynamics at moderate resolution over large regions should be feasible.

  8. Structural control of ultra-fine CoPt nanodot arrays via electrodeposition process

    NASA Astrophysics Data System (ADS)

    Wodarz, Siggi; Hasegawa, Takashi; Ishio, Shunji; Homma, Takayuki

    2017-05-01

    CoPt nanodot arrays were fabricated by combining electrodeposition and electron beam lithography (EBL) for the use of bit-patterned media (BPM). To achieve precise control of deposition uniformity and coercivity of the CoPt nanodot arrays, their crystal structure and magnetic properties were controlled by controlling the diffusion state of metal ions from the initial deposition stage with the application of bath agitation. Following bath agitation, the composition gradient of the CoPt alloy with thickness was mitigated to have a near-ideal alloy composition of Co:Pt =80:20, which induces epitaxial-like growth from Ru substrate, thus resulting in the improvement of the crystal orientation of the hcp (002) structure from its initial deposition stages. Furthermore, the cross-sectional transmission electron microscope (TEM) analysis of the nanodots deposited with bath agitation showed CoPt growth along its c-axis oriented in the perpendicular direction, having uniform lattice fringes on the hcp (002) plane from the Ru underlayer interface, which is a significant factor to induce perpendicular magnetic anisotropy. Magnetic characterization of the CoPt nanodot arrays showed increase in the perpendicular coercivity and squareness of the hysteresis loops from 2.0 kOe and 0.64 (without agitation) to 4.0 kOe and 0.87 with bath agitation. Based on the detailed characterization of nanodot arrays, the precise crystal structure control of the nanodot arrays with ultra-high recording density by electrochemical process was successfully demonstrated.

  9. An adaptive Hidden Markov model for activity recognition based on a wearable multi-sensor device.

    PubMed

    Li, Zhen; Wei, Zhiqiang; Yue, Yaofeng; Wang, Hao; Jia, Wenyan; Burke, Lora E; Baranowski, Thomas; Sun, Mingui

    2015-05-01

    Human activity recognition is important in the study of personal health, wellness and lifestyle. In order to acquire human activity information from the personal space, many wearable multi-sensor devices have been developed. In this paper, a novel technique for automatic activity recognition based on multi-sensor data is presented. In order to utilize these data efficiently and overcome the big data problem, an offline adaptive-Hidden Markov Model (HMM) is proposed. A sensor selection scheme is implemented based on an improved Viterbi algorithm. A new method is proposed that incorporates personal experience into the HMM model as a priori information. Experiments are conducted using a personal wearable computer eButton consisting of multiple sensors. Our comparative study with the standard HMM and other alternative methods in processing the eButton data have shown that our method is more robust and efficient, providing a useful tool to evaluate human activity and lifestyle.

  10. Multi-Sensor Consensus Estimation of State, Sensor Biases and Unknown Input

    PubMed Central

    Zhou, Jie; Liang, Yan; Yang, Feng; Xu, Linfeng; Pan, Quan

    2016-01-01

    This paper addresses the problem of the joint estimation of system state and generalized sensor bias (GSB) under a common unknown input (UI) in the case of bias evolution in a heterogeneous sensor network. First, the equivalent UI-free GSB dynamic model is derived and the local optimal estimates of system state and sensor bias are obtained in each sensor node; Second, based on the state and bias estimates obtained by each node from its neighbors, the UI is estimated via the least-squares method, and then the state estimates are fused via consensus processing; Finally, the multi-sensor bias estimates are further refined based on the consensus estimate of the UI. A numerical example of distributed multi-sensor target tracking is presented to illustrate the proposed filter. PMID:27598156

  11. Multi-Sensor Consensus Estimation of State, Sensor Biases and Unknown Input.

    PubMed

    Zhou, Jie; Liang, Yan; Yang, Feng; Xu, Linfeng; Pan, Quan

    2016-09-01

    This paper addresses the problem of the joint estimation of system state and generalized sensor bias (GSB) under a common unknown input (UI) in the case of bias evolution in a heterogeneous sensor network. First, the equivalent UI-free GSB dynamic model is derived and the local optimal estimates of system state and sensor bias are obtained in each sensor node; Second, based on the state and bias estimates obtained by each node from its neighbors, the UI is estimated via the least-squares method, and then the state estimates are fused via consensus processing; Finally, the multi-sensor bias estimates are further refined based on the consensus estimate of the UI. A numerical example of distributed multi-sensor target tracking is presented to illustrate the proposed filter.

  12. Sub-threshold signal processing in arrays of non-identical nanostructures.

    PubMed

    Cervera, Javier; Manzanares, José A; Mafé, Salvador

    2011-10-28

    Weak input signals are routinely processed by molecular-scaled biological networks composed of non-identical units that operate correctly in a noisy environment. In order to show that artificial nanostructures can mimic this behavior, we explore theoretically noise-assisted signal processing in arrays of metallic nanoparticles functionalized with organic ligands that act as tunneling junctions connecting the nanoparticle to the external electrodes. The electronic transfer through the nanostructure is based on the Coulomb blockade and tunneling effects. Because of the fabrication uncertainties, these nanostructures are expected to show a high variability in their physical characteristics and a diversity-induced static noise should be considered together with the dynamic noise caused by thermal fluctuations. This static noise originates from the hardware variability and produces fluctuations in the threshold potential of the individual nanoparticles arranged in a parallel array. The correlation between different input (potential) and output (current) signals in the array is analyzed as a function of temperature, applied voltage, and the variability in the electrical properties of the nanostructures. Extensive kinetic Monte Carlo simulations with nanostructures whose basic properties have been demonstrated experimentally show that variability can enhance the correlation, even for the case of weak signals and high variability, provided that the signal is processed by a sufficiently high number of nanostructures. Moderate redundancy permits us not only to minimize the adverse effects of the hardware variability but also to take advantage of the nanoparticles' threshold fluctuations to increase the detection range at low temperatures. This conclusion holds for the average behavior of a moderately large statistical ensemble of non-identical nanostructures processing different types of input signals and suggests that variability could be beneficial for signal processing

  13. Batch-processed semiconductor gas sensor array for the selective detection of NOx in automotive exhaust gas

    NASA Astrophysics Data System (ADS)

    Jang, Hani; Kim, Minki; Kim, Yongjun

    2016-12-01

    This paper reports on a semiconductor gas sensor array to detect nitrogen oxides (NOx) in automotive exhaust gas. The proposed semiconductor gas sensor array consisted of one common electrode and three individual electrodes to minimize the size of the sensor array, and three sensing layers [TiO2 + SnO2 (15 wt%), SnO2, and Ga2O3] were deposited using screen printing. In addition, sensing materials were sintered under the same conditions in order to take advantage of batch processing. The sensing properties of the proposed sensor array were verified by experimental measurements, and the selectivity improved by using pattern recognition.

  14. A high-resolution algorithm for wave number estimation using holographic array processing

    NASA Astrophysics Data System (ADS)

    Roux, Philippe; Cassereau, Didier; Roux, André

    2004-03-01

    This paper presents an original way to perform wave number inversion from simulated data obtained in a noisy shallow-water environment. In the studied configuration an acoustic source is horizontally towed with respect to a vertical hydrophone array. The inversion is achieved from the combination of three ingredients. First, a modified version of the Prony algorithm is presented and numerical comparison is made to another high-resolution wave number inversion algorithm based on the matrix-pencil technique. Second, knowing that these high-resolution algorithms are classically sensitive to noise, the use of a holographic array processing enables improvement of the signal-to-noise ratio before the inversion is performed. Last, particular care is taken in the representations of the solutions in the wave number space to improve resolution without suffering from aliasing. The dependence of this wave number inversion algorithm on the relevant parameters of the problem is discussed.

  15. Reversible Back-Propagation Imaging Algorithm for Post-Processing of Ultrasonic Array Data

    NASA Astrophysics Data System (ADS)

    Velichko, A.; Wilcox, P. D.

    2009-03-01

    The paper describes a method for processing data from an ultrasonic transducer array. The proposed algorithm is formulated in such a way that it is reversible, i.e. the raw data set can be recovered from the image. This is of practical significance because it allows the raw-data to be spatially filtered using the image to extract, for example, only the raw data associated with a particular reflector. The method is tested on experimental data obtained from a commercial 64-element, 5-MHZ array on an aluminium specimen that contains a number of machined slots and side-drilled holes. The raw transmitter-receiver data corresponded to each reflector is extracted and the scattering matrices of different reflectors are reconstructed. It allows the signals from 1-mm-long slot and a 1-mm-diameter hole to be clearly distinguished and the orientation and the size of the slots to be determined.

  16. Seismic Monitoring with Small Aperture Arrays Under Strong Noise Conditions: Algorithms, Technique, System Design and Experimental Data Processing

    DTIC Science & Technology

    1995-05-01

    tasking Moscow Iris Data Center as follows: Investigate array processing techniques and apply them to small seismic events and to events with weak surface...28 7. Estimation of plane wave apparent velocities based on data from three...8 9 1 .7 Program "arloc": event locating based on single array data

  17. An asynchronous multi-sensor micro control unit for wireless body sensor networks (WBSNs).

    PubMed

    Chen, Chiung-An; Chen, Shih-Lun; Huang, Hong-Yi; Luo, Ching-Hsing

    2011-01-01

    In this work, an asynchronous multi-sensor micro control unit (MCU) core is proposed for wireless body sensor networks (WBSNs). It consists of asynchronous interfaces, a power management unit, a multi-sensor controller, a data encoder (DE), and an error correct coder (ECC). To improve the system performance and expansion abilities, the asynchronous interface is created for handshaking different clock domains between ADC and RF with MCU. To increase the use time of the WBSN system, a power management technique is developed for reducing power consumption. In addition, the multi-sensor controller is designed for detecting various biomedical signals. To prevent loss error from wireless transmission, use of an error correct coding technique is important in biomedical applications. The data encoder is added for lossless compression of various biomedical signals with a compression ratio of almost three. This design is successfully tested on a FPGA board. The VLSI architecture of this work contains 2.68-K gate counts and consumes power 496-μW at 133-MHz processing rate by using TSMC 0.13-μm CMOS process. Compared with the previous techniques, this work offers higher performance, more functions, and lower hardware cost than other micro controller designs.

  18. An Asynchronous Multi-Sensor Micro Control Unit for Wireless Body Sensor Networks (WBSNs)

    PubMed Central

    Chen, Chiung-An; Chen, Shih-Lun; Huang, Hong-Yi; Luo, Ching-Hsing

    2011-01-01

    In this work, an asynchronous multi-sensor micro control unit (MCU) core is proposed for wireless body sensor networks (WBSNs). It consists of asynchronous interfaces, a power management unit, a multi-sensor controller, a data encoder (DE), and an error correct coder (ECC). To improve the system performance and expansion abilities, the asynchronous interface is created for handshaking different clock domains between ADC and RF with MCU. To increase the use time of the WBSN system, a power management technique is developed for reducing power consumption. In addition, the multi-sensor controller is designed for detecting various biomedical signals. To prevent loss error from wireless transmission, use of an error correct coding technique is important in biomedical applications. The data encoder is added for lossless compression of various biomedical signals with a compression ratio of almost three. This design is successfully tested on a FPGA board. The VLSI architecture of this work contains 2.68-K gate counts and consumes power 496-μW at 133-MHz processing rate by using TSMC 0.13-μm CMOS process. Compared with the previous techniques, this work offers higher performance, more functions, and lower hardware cost than other micro controller designs. PMID:22164000

  19. Process development for automated solar cell and module production. Task 4: automated array assembly

    SciTech Connect

    Hagerty, J.J.

    1980-06-30

    The scope of work under this contract involves specifying a process sequence which can be used in conjunction with automated equipment for the mass production of solar cell modules for terrestrial use. This process sequence is then critically analyzed from a technical and economic standpoint to determine the technological readiness of each process step for implementation. The process steps are ranked according to the degree of development effort required and according to their significance to the overall process. Under this contract the steps receiving analysis were: back contact metallization, automated cell array layup/interconnect, and module edge sealing. For automated layup/interconnect both hard automation and programmable automation (using an industrial robot) were studied. The programmable automation system was then selected for actual hardware development. Economic analysis using the SAMICS system has been performed during these studies to assure that development efforts have been directed towards the ultimate goal of price reduction. Details are given. (WHK)

  20. Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

    NASA Astrophysics Data System (ADS)

    Tu, K. T.; Chung, C. K.

    2016-06-01

    An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

  1. Optoelectronic signal processing for phased-array antennas II; Proceedings of the Meeting, Los Angeles, CA, Jan. 16, 17, 1990

    NASA Astrophysics Data System (ADS)

    Hendrickson, Brian M.; Koepf, Gerhard A.

    Various papers on optoelectronic signal processing for phased-array antennas (PAAs) are presented. Individual topics addressed include: the dynamics of high-frequency lasers, an electrooptic phase modulator for PA applications, a laser mixer for microwave fiber optics, optical control of microwaves with III-V semiconductor optical waveguides, a high-dynamic-range modulator for microwave PAs, the high-modulation-rate potential of surface-emitter laser-diode arrays, an electrooptical switch for antenna beam steering, and adaptive PA radar processing using photorefractive crystals. Also discussed are an optical processor for array antenna beam shaping and steering, an integrated optical Butler matrix for beam forming in PAAs, an acoustooptic/photorefractive processor for adaptive antenna arrays, BER testing of fiber-optic data links for MMIC-based phased-array antennas, and the design of an optically controlled K(a)-band GaAs MMIC PAA.

  2. β-Decay Studies of r-Process Nuclei Using the Advanced Implantation Detector Array (AIDA)

    NASA Astrophysics Data System (ADS)

    Griffin, C. J.; Davinson, T.; Estrade, A.; Braga, D.; Burrows, I.; Coleman-Smith, P. J.; Grahn, T.; Grant, A.; Harkness-Brennan, L. J.; Kiss, G.; Kogimtzis, M.; Lazarus, I. H.; Letts, S. C.; Liu, Z.; Lorusso, G.; Matsui, K.; Nishimura, S.; Page, R. D.; Prydderch, M.; Phong, V. H.; Pucknell, V. F. E.; Rinta-Antila, S.; Roberts, O. J.; Seddon, D. A.; Simpson, J.; Thomas, S. L.; Woods, P. J.

    Thought to produce around half of all isotopes heavier than iron, the r-process is a key mechanism for nucleosynthesis. However, a complete description of the r-process is still lacking and many unknowns remain. Experimental determination of β-decay half-lives and β-delayed neutron emission probabilities along the r-process path would help to facilitate a greater understanding of this process. The Advanced Implantation Detector Array (AIDA) represents the latest generation of silicon implantation detectors for β-decay studies with fast radioactive ion beams. Preliminary results from commissioning experiments demonstrate successful operation of AIDA and analysis of the data obtained during the first official AIDA experiments is now under-way.

  3. A Reconfigurable Readout Integrated Circuit for Heterogeneous Display-Based Multi-Sensor Systems.

    PubMed

    Park, Kyeonghwan; Kim, Seung Mok; Eom, Won-Jin; Kim, Jae Joon

    2017-04-03

    This paper presents a reconfigurable multi-sensor interface and its readout integrated circuit (ROIC) for display-based multi-sensor systems, which builds up multi-sensor functions by utilizing touch screen panels. In addition to inherent touch detection, physiological and environmental sensor interfaces are incorporated. The reconfigurable feature is effectively implemented by proposing two basis readout topologies of amplifier-based and oscillator-based circuits. For noise-immune design against various noises from inherent human-touch operations, an alternate-sampling error-correction scheme is proposed and integrated inside the ROIC, achieving a 12-bit resolution of successive approximation register (SAR) of analog-to-digital conversion without additional calibrations. A ROIC prototype that includes the whole proposed functions and data converters was fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS) process, and its feasibility was experimentally verified to support multiple heterogeneous sensing functions of touch, electrocardiogram, body impedance, and environmental sensors.

  4. Multisensor Super Resolution Using Directionally-Adaptive Regularization for UAV Images

    PubMed Central

    Kang, Wonseok; Yu, Soohwan; Ko, Seungyong; Paik, Joonki

    2015-01-01

    In various unmanned aerial vehicle (UAV) imaging applications, the multisensor super-resolution (SR) technique has become a chronic problem and attracted increasing attention. Multisensor SR algorithms utilize multispectral low-resolution (LR) images to make a higher resolution (HR) image to improve the performance of the UAV imaging system. The primary objective of the paper is to develop a multisensor SR method based on the existing multispectral imaging framework instead of using additional sensors. In order to restore image details without noise amplification or unnatural post-processing artifacts, this paper presents an improved regularized SR algorithm by combining the directionally-adaptive constraints and multiscale non-local means (NLM) filter. As a result, the proposed method can overcome the physical limitation of multispectral sensors by estimating the color HR image from a set of multispectral LR images using intensity-hue-saturation (IHS) image fusion. Experimental results show that the proposed method provides better SR results than existing state-of-the-art SR methods in the sense of objective measures. PMID:26007744

  5. Distinctive Order Based Self-Similarity descriptor for multi-sensor remote sensing image matching

    NASA Astrophysics Data System (ADS)

    Sedaghat, Amin; Ebadi, Hamid

    2015-10-01

    Robust, well-distributed and accurate feature matching in multi-sensor remote sensing image is a difficult task duo to significant geometric and illumination differences. In this paper, a robust and effective image matching approach is presented for multi-sensor remote sensing images. The proposed approach consists of three main steps. In the first step, UR-SIFT (Uniform robust scale invariant feature transform) algorithm is applied for uniform and dense local feature extraction. In the second step, a novel descriptor namely Distinctive Order Based Self Similarity descriptor, DOBSS descriptor, is computed for each extracted feature. Finally, a cross matching process followed by a consistency check in the projective transformation model is performed for feature correspondence and mismatch elimination. The proposed method was successfully applied for matching various multi-sensor satellite images as: ETM+, SPOT 4, SPOT 5, ASTER, IRS, SPOT 6, QuickBird, GeoEye and Worldview sensors, and the results demonstrate its robustness and capability compared to common image matching techniques such as SIFT, PIIFD, GLOH, LIOP and LSS.

  6. A Reconfigurable Readout Integrated Circuit for Heterogeneous Display-Based Multi-Sensor Systems

    PubMed Central

    Park, Kyeonghwan; Kim, Seung Mok; Eom, Won-Jin; Kim, Jae Joon

    2017-01-01

    This paper presents a reconfigurable multi-sensor interface and its readout integrated circuit (ROIC) for display-based multi-sensor systems, which builds up multi-sensor functions by utilizing touch screen panels. In addition to inherent touch detection, physiological and environmental sensor interfaces are incorporated. The reconfigurable feature is effectively implemented by proposing two basis readout topologies of amplifier-based and oscillator-based circuits. For noise-immune design against various noises from inherent human-touch operations, an alternate-sampling error-correction scheme is proposed and integrated inside the ROIC, achieving a 12-bit resolution of successive approximation register (SAR) of analog-to-digital conversion without additional calibrations. A ROIC prototype that includes the whole proposed functions and data converters was fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS) process, and its feasibility was experimentally verified to support multiple heterogeneous sensing functions of touch, electrocardiogram, body impedance, and environmental sensors. PMID:28368355

  7. Multisensor Super Resolution Using Directionally-Adaptive Regularization for UAV Images.

    PubMed

    Kang, Wonseok; Yu, Soohwan; Ko, Seungyong; Paik, Joonki

    2015-05-22

    In various unmanned aerial vehicle (UAV) imaging applications, the multisensor super-resolution (SR) technique has become a chronic problem and attracted increasing attention. Multisensor SR algorithms utilize multispectral low-resolution (LR) images to make a higher resolution (HR) image to improve the performance of the UAV imaging system. The primary objective of the paper is to develop a multisensor SR method based on the existing multispectral imaging framework instead of using additional sensors. In order to restore image details without noise amplification or unnatural post-processing artifacts, this paper presents an improved regularized SR algorithm by combining the directionally-adaptive constraints and multiscale non-local means (NLM) filter. As a result, the proposed method can overcome the physical limitation of multispectral sensors by estimating the color HR image from a set of multispectral LR images using intensity-hue-saturation (IHS) image fusion. Experimental results show that the proposed method provides better SR results than existing state-of-the-art SR methods in the sense of objective measures.

  8. Distributed multi-sensor particle filter for bearings-only tracking

    NASA Astrophysics Data System (ADS)

    Zhang, Jungen; Ji, Hongbing

    2012-02-01

    In this article, the classical bearings-only tracking (BOT) problem for a single target is addressed, which belongs to the general class of non-linear filtering problems. Due to the fact that the radial distance observability of the target is poor, the algorithm-based sequential Monte-Carlo (particle filtering, PF) methods generally show instability and filter divergence. A new stable distributed multi-sensor PF method is proposed for BOT. The sensors process their measurements at their sites using a hierarchical PF approach, which transforms the BOT problem from Cartesian coordinate to the logarithmic polar coordinate and separates the observable components from the unobservable components of the target. In the fusion centre, the target state can be estimated by utilising the multi-sensor optimal information fusion rule. Furthermore, the computation of a theoretical Cramer-Rao lower bound is given for the multi-sensor BOT problem. Simulation results illustrate that the proposed tracking method can provide better performances than the traditional PF method.

  9. Array Processing and Forward Modeling Methods for the Analysis of Stiffened, Fluid-Loaded Cylindrical Shells.

    NASA Astrophysics Data System (ADS)

    Bondaryk, Joseph E.

    This thesis investigates array processing and forward modeling methods for the analysis of experimental, structural acoustic data to understand wave propagation on fluid-loaded, elastic, cylindrical shells in the mid -frequency range, 2 < ka < 12. The transient, acoustic, in-plane, bistatic scattering response to wideband, plane waves at various angles of incidence was collected by a synthetic array for three shells, a finite, air-filled, empty thin shell, a duplicate shell stiffened with four unequally spaced ring-stiffeners and a duplicate ribbed shell augmented by resiliently-mounted, wave-bearing, internal structural elements. Array and signal processing techniques, including source deconvolution, array weighting, conventional focusing and the removal of the geometrically scattered contribution, are used to transform the collected data to a more easily interpreted representation. The resulting waveforms show that part of the transient, dynamic, structural response of the shell surface which is capable of radiating to the far field. Compressional membrane waves are directly observable in this representation and evidence of flexural membrane waves is present. Comparisons between the shells show energy compartmentalized by the ring stiffeners and coupled into the wave-bearing internals. Energy calculations show a decay rate of 30dB/msec due to radiation for the Empty shell but only 10dB/msec for the other shells at bow incidence. The Radon Transform is used to estimate the reflection coefficient of compressional waves at the shell endcap as 0.2. The measurement array does not provide enough resolution to allow use of this technique to determine the reflection, transmission and coupling coefficients at the ring stiffeners. Therefore, a forward modeling technique is used to further analyze the 0^ circ incidence case. This modeling couples a Transmission Line model of the shell with a Simulated Annealing approach to multi-dimensional, parameter estimation. This

  10. Evaluation of the Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Array

    NASA Technical Reports Server (NTRS)

    Pang, Jackson; Liddicoat, Albert; Ralston, Jesse; Pingree, Paula

    2006-01-01

    The current implementation of the Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Arrays (TRIGA) is equipped with CFDP protocol and CCSDS Telemetry and Telecommand framing schemes to replace the CPU intensive software counterpart implementation for reliable deep space communication. We present the hardware/software co-design methodology used to accomplish high data rate throughput. The hardware CFDP protocol stack implementation is then compared against the two recent flight implementations. The results from our experiments show that TRIGA offers more than 3 orders of magnitude throughput improvement with less than one-tenth of the power consumption.

  11. Process Development for Automated Solar Cell and Module Production. Task 4: Automated Array Assembly

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A baseline sequence for the manufacture of solar cell modules was specified. Starting with silicon wafers, the process goes through damage etching, texture etching, junction formation, plasma edge etch, aluminum back surface field formation, and screen printed metallization to produce finished solar cells. The cells were then series connected on a ribbon and bonded into a finished glass tedlar module. A number of steps required additional developmental effort to verify technical and economic feasibility. These steps include texture etching, plasma edge etch, aluminum back surface field formation, array layup and interconnect, and module edge sealing and framing.

  12. Evaluation of the Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Array

    NASA Technical Reports Server (NTRS)

    Pang, Jackson; Liddicoat, Albert; Ralston, Jesse; Pingree, Paula

    2006-01-01

    The current implementation of the Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Arrays (TRIGA) is equipped with CFDP protocol and CCSDS Telemetry and Telecommand framing schemes to replace the CPU intensive software counterpart implementation for reliable deep space communication. We present the hardware/software co-design methodology used to accomplish high data rate throughput. The hardware CFDP protocol stack implementation is then compared against the two recent flight implementations. The results from our experiments show that TRIGA offers more than 3 orders of magnitude throughput improvement with less than one-tenth of the power consumption.

  13. An Evaluation of Signal Processing Tools for Improving Phased Array Ultrasonic Weld Inspection

    SciTech Connect

    Ramuhalli, Pradeep; Cinson, Anthony D.; Crawford, Susan L.; Harris, Robert V.; Diaz, Aaron A.; Anderson, Michael T.

    2011-03-24

    Cast austenitic stainless steel (CASS) commonly used in U.S. nuclear power plants is a coarse-grained, elastically anisotropic material. The coarse-grained nature of CASS makes ultrasonic inspection of in-service components difficult. Recently, low-frequency phased array ultrasound has emerged as a candidate for the CASS piping weld inspection. However, issues such as low signal-to-noise ratio and difficulty in discriminating between flaw and non-flaw signals remain. This paper discusses the evaluation of a number of signal processing algorithms for improving flaw detection in CASS materials. The full paper provides details of the algorithms being evaluated, along with preliminary results.

  14. The Role of Water Vapor and Dissociative Recombination Processes in Solar Array Arc Initiation

    NASA Technical Reports Server (NTRS)

    Galofar, J.; Vayner, B.; Degroot, W.; Ferguson, D.

    2002-01-01

    Experimental plasma arc investigations involving the onset of arc initiation for a negatively biased solar array immersed in low-density plasma have been performed. Previous studies into the arc initiation process have shown that the most probable arcing sites tend to occur at the triple junction involving the conductor, dielectric and plasma. More recently our own experiments have led us to believe that water vapor is the main causal factor behind the arc initiation process. Assuming the main component of the expelled plasma cloud by weight is water, the fastest process available is dissociative recombination (H2O(+) + e(-) (goes to) H* + OH*). A model that agrees with the observed dependency of arc current pulse width on the square root of capacitance is presented. A 400 MHz digital storage scope and current probe was used to detect arcs at the triple junction of a solar array. Simultaneous measurements of the arc trigger pulse, the gate pulse, the arc current and the arc voltage were then obtained. Finally, a large number of measurements of individual arc spectra were obtained in very short time intervals, ranging from 10 to 30 microseconds, using a 1/4 a spectrometer coupled with a gated intensified CCD. The spectrometer was systematically tuned to obtain optical arc spectra over the entire wavelength range of 260 to 680 nanometers. All relevant atomic lines and molecular bands were then identified.

  15. Automatic Defect Detection for TFT-LCD Array Process Using Quasiconformal Kernel Support Vector Data Description

    PubMed Central

    Liu, Yi-Hung; Chen, Yan-Jen

    2011-01-01

    Defect detection has been considered an efficient way to increase the yield rate of panels in thin film transistor liquid crystal display (TFT-LCD) manufacturing. In this study we focus on the array process since it is the first and key process in TFT-LCD manufacturing. Various defects occur in the array process, and some of them could cause great damage to the LCD panels. Thus, how to design a method that can robustly detect defects from the images captured from the surface of LCD panels has become crucial. Previously, support vector data description (SVDD) has been successfully applied to LCD defect detection. However, its generalization performance is limited. In this paper, we propose a novel one-class machine learning method, called quasiconformal kernel SVDD (QK-SVDD) to address this issue. The QK-SVDD can significantly improve generalization performance of the traditional SVDD by introducing the quasiconformal transformation into a predefined kernel. Experimental results, carried out on real LCD images provided by an LCD manufacturer in Taiwan, indicate that the proposed QK-SVDD not only obtains a high defect detection rate of 96%, but also greatly improves generalization performance of SVDD. The improvement has shown to be over 30%. In addition, results also show that the QK-SVDD defect detector is able to accomplish the task of defect detection on an LCD image within 60 ms. PMID:22016625

  16. SST dual-mirror telescope for Cherenkov Telescope Array: an innovative mirror manufacturing process

    NASA Astrophysics Data System (ADS)

    Dumas, Delphine; Huet, Jean-Michel; Dournaux, Jean-Laurent; Laporte, Philippe; Rulten, Cameron; Schmoll, Jurgen; Sol, Hélène; Sayède, Frédéric; Micolon, Patrice; Glicenstein, Jean-François; Peyaud, Bernard

    2014-07-01

    The Observatoire de Paris is constructing a prototype Small-Sized Telescope (SST) for the Cherenkov Telescope Array (CTA), named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical design. Considering the mirrors size and its specific curvature and the optical requirements for the Cherenkov imaging telescope, a non-conventional process has been used for designing and manufacturing the mirrors of the SST-GATE prototype. Based on machining, polishing and coating of aluminium bulk samples, this process has been validated by simulation and tests that will be detailed in this paper after a discussion on the Schwarzschild-Couder optical design which so far has never been used to design ground based telescopes. Even if the SST-GATE is a prototype for small size telescopes of the CTA array, the primary mirror of the telescope is 4 meters diameter, and it has to be segmented. Due to the dual-mirror configuration, the alignment is a complex task that needs a well defined and precise process that will be discussed in this paper.

  17. Multisensor Target Detection And Classification

    NASA Astrophysics Data System (ADS)

    Ruck, Dennis W.; Rogers, Steven K.; Mills, James P.; Kabrisky, Matthew

    1988-08-01

    In this paper a new approach to the detection and classification of tactical targets using a multifunction laser radar sensor is developed. Targets of interest are tanks, jeeps, trucks, and other vehicles. Doppler images are segmented by developing a new technique which compensates for spurious doppler returns. Relative range images are segmented using an approach based on range gradients. The resultant shapes in the segmented images are then classified using Zernike moment invariants as shape descriptors. Two classification decision rules are implemented: a classical statistical nearest-neighbor approach and a multilayer perceptron architecture. The doppler segmentation algorithm was applied to a set of 180 real sensor images. An accurate segmentation was obtained for 89 percent of the images. The new doppler segmentation proved to be a robust method, and the moment invariants were effective in discriminating the tactical targets. Tanks were classified correctly 86 percent of the time. The most important result of this research is the demonstration of the use of a new information processing architecture for image processing applications.

  18. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Technical Reports Server (NTRS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; Koopman, B. J.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Pappas, C. G.; Salatino, M.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-01-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN(sub x)) materials and microwave structures, and the resulting performance improvements.

  19. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Astrophysics Data System (ADS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; Koopman, B. J.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Pappas, C. G.; Salatino, M.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-08-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN_x) materials and microwave structures, and the resulting performance improvements.

  20. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Technical Reports Server (NTRS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; hide

    2016-01-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN(sub x)) materials and microwave structures, and the resulting performance improvements.

  1. Post-Processing of the Full Matrix of Ultrasonic Transmit-Receive Array Data for Guided Wave Pipe Inspection

    NASA Astrophysics Data System (ADS)

    Velichko, A.; Wilcox, P. D.

    2009-03-01

    The paper describes a method for processing data from a guided wave transducer array on a pipe. The raw data set from such an array contains the full matrix of time-domain signals from each transmitter-receiver combination. It is shown that for certain configurations of an array the total focusing method can be applied which allows the array to be focused at every point on a pipe surface in both transmission and reception. The effect of array configuration parameters on the sensitivity of the proposed method to the random and coherent noise is discussed. Experimental results are presented using electromagnetic acoustic transducers (EMAT) for exciting and detecting the S0 Lamb wave mode in a 12 inch steel pipe at 200 kHz excitation frequency. The results show that using the imaging algorithm a 2-mm-diameter (0.08 wavelength) half-thickness hole can be detected.

  2. High-throughput fabrication of micrometer-sized compound parabolic mirror arrays by using parallel laser direct-write processing

    NASA Astrophysics Data System (ADS)

    Yan, Wensheng; Cumming, Benjamin P.; Gu, Min

    2015-07-01

    Micrometer-sized parabolic mirror arrays have significant applications in both light emitting diodes and solar cells. However, low fabrication throughput has been identified as major obstacle for the mirror arrays towards large-scale applications due to the serial nature of the conventional method. Here, the mirror arrays are fabricated by using a parallel laser direct-write processing, which addresses this barrier. In addition, it is demonstrated that the parallel writing is able to fabricate complex arrays besides simple arrays and thus offers wider applications. Optical measurements show that each single mirror confines the full-width at half-maximum value to as small as 17.8 μm at the height of 150 μm whilst providing a transmittance of up to 68.3% at a wavelength of 633 nm in good agreement with the calculation values.

  3. Formation process of TiO2 nanotube arrays prepared by anodic oxidation method.

    PubMed

    Li, Hongyi; Liu, Man; Wang, Hong; Wu, Junshu; Su, Penglei; Li, Dasheng; Wang, Jinshu

    2013-06-01

    TiO2 nanotube array thin films have great potential in many fields, such as solar cell, photo catalyst, photo-induced cathodic protection for metals and bioactivity. In order to investigate the formation process of the TiO2 nanotube array thin films, the EIS spectrum and current density were measured during the anodic oxidation. The results showed that the formation process could be divided into four stages. The current density decreased sharply at the first stage, and then increased at the second stage, followed by declining and finally remained constant value. In addition, the current density increased with the anodic voltage. The EIS spectrum varied in different stage. The simulated circuit was composed three sections, the first sections indicated the resistance of the electrolyte, the second one gave the double layer structure between the electrolyte and titanium electrode, the third one was a inductive loop, which represented the anions absorbed on the surface of the TiO2 nanotube's wall. The more cations were absorbed, the higher value of the inductive loop would be. The EIS results showed that the value increased with the outer voltage, which means that more cations were absorbed under the higher anodic voltage.

  4. Multisensor data fusion for IED threat detection

    NASA Astrophysics Data System (ADS)

    Mees, Wim; Heremans, Roel

    2012-10-01

    In this paper we present the multi-sensor registration and fusion algorithms that were developed for a force protection research project in order to detect threats against military patrol vehicles. The fusion is performed at object level, using a hierarchical evidence aggregation approach. It first uses expert domain knowledge about the features used to characterize the detected threats, that is implemented in the form of a fuzzy expert system. The next level consists in fusing intra-sensor and inter-sensor information. Here an ordered weighted averaging operator is used. The object level fusion between candidate threats that are detected asynchronously on a moving vehicle by sensors with different imaging geometries, requires an accurate sensor to world coordinate transformation. This image registration will also be discussed in this paper.

  5. Expanding Coherent Array Processing to Larger Apertures using Empirical Matched Field Processing

    DTIC Science & Technology

    2009-09-30

    blasts in Eastern Kazakhstan, in Seism . Res. Lett., 79:393-399. Prieto, G A., R. L. Parker, and F. L. Vernon (2009). A Fortran 90 library for...processing approach to real time network detection, phase association, and threshold monitoring, in Bull. Seism . Soc. Am. 79:1927-1940. Thomson, D. J. (1982

  6. Correlation of lattice defects and thermal processing in the crystallization of titania nanotube arrays

    NASA Astrophysics Data System (ADS)

    Hosseinpour, Pegah M.; Yung, Daniel; Panaitescu, Eugen; Heiman, Don; Menon, Latika; Budil, David; Lewis, Laura H.

    2014-12-01

    Titania nanotubes have the potential to be employed in a wide range of energy-related applications such as solar energy-harvesting devices and hydrogen production. As the functionality of titania nanostructures is critically affected by their morphology and crystallinity, it is necessary to understand and control these factors in order to engineer useful materials for green applications. In this study, electrochemically-synthesized titania nanotube arrays were thermally processed in inert and reducing environments to isolate the role of post-synthesis processing conditions on the crystallization behavior, electronic structure and morphology development in titania nanotubes, correlated with the nanotube functionality. Structural and calorimetric studies revealed that as-synthesized amorphous nanotubes crystallize to form the anatase structure in a three-stage process that is facilitated by the creation of structural defects. It is concluded that processing in a reducing gas atmosphere versus in an inert environment provides a larger unit cell volume and a higher concentration of Ti3+ associated with oxygen vacancies, thereby reducing the activation energy of crystallization. Further, post-synthesis annealing in either reducing or inert atmospheres produces pronounced morphological changes, confirming that the nanotube arrays thermally transform into a porous morphology consisting of a fragmented tubular architecture surrounded by a network of connected nanoparticles. This study links explicit data concerning morphology, crystallization and defects, and shows that the annealing gas environment determines the details of the crystal structure, the electronic structure and the morphology of titania nanotubes. These factors, in turn, impact the charge transport and consequently the functionality of these nanotubes as photocatalysts.

  7. Coupled process of plastics pyrolysis and chemical vapor deposition for controllable synthesis of vertically aligned carbon nanotube arrays

    NASA Astrophysics Data System (ADS)

    Yang, Zhou; Zhang, Qiang; Luo, Guohua; Huang, Jia-Qi; Zhao, Meng-Qiang; Wei, Fei

    2010-08-01

    Efficient conversion of waste plastics into advanced materials is of conspicuous environmental, social and economic benefits. A coupled process of plastic pyrolysis and chemical vapor deposition for vertically aligned carbon nanotube (CNT) array growth was proposed. Various kinds of plastics, such as polypropylene, polyethylene, and polyvinyl chloride, were used as carbon sources for the controllable growth of CNT arrays. The relationship between the length of CNT arrays and the growth time was investigated. It was found that the length of aligned CNTs increased with prolonged growth time. CNT arrays with a length of 500 μm were obtained for a 40-min growth and the average growth rate was estimated to be 12 μm/min. The diameter of CNTs in the arrays can be modulated by controlling the growth temperature and the feeding rate of ferrocene. In addition, substrates with larger specific surface area such as ceramic spheres, quartz fibers, and quartz particles, were adopted to support the growth of CNT arrays. Those results provide strong evidence for the feasibility of conversion from waste plastics into CNT arrays via this reported sustainable materials processing.

  8. Parallel pipeline networking and signal processing with field-programmable gate arrays (FPGAs) and VCSEL-MSM smart pixels

    NASA Astrophysics Data System (ADS)

    Kuznia, C. B.; Sawchuk, Alexander A.; Zhang, Liping; Hoanca, Bogdan; Hong, Sunkwang; Min, Chris; Pansatiankul, Dhawat E.; Alpaslan, Zahir Y.

    2000-05-01

    We present a networking and signal processing architecture called Transpar-TR (Translucent Smart Pixel Array-Token- Ring) that utilizes smart pixel technology to perform 2D parallel optical data transfer between digital processing nodes. Transpar-TR moves data through the network in the form of 3D packets (2D spatial and 1D time). By utilizing many spatial parallel channels, Transpar-TR can achieve high throughput, low latency communication between nodes, even with each channel operating at moderate data rates. The 2D array of optical channels is created by an array of smart pixels, each with an optical input and optical output. Each smart pixel consists of two sections, an optical network interface and ALU-based processor with local memory. The optical network interface is responsible for transmitting and receiving optical data packets using a slotted token ring network protocol. The smart pixel array operates as a single-instruction multiple-data processor when processing data. The Transpar-TR network, consisting of networked smart pixel arrays, can perform pipelined parallel processing very efficiently on 2D data structures such as images and video. This paper discusses the Transpar-TR implementation in which each node is the printed circuit board integration of a VCSEL-MSM chip, a transimpedance receiver array chip and an FPGA chip.

  9. Fabricating process of hollow out-of-plane Ni microneedle arrays and properties of the integrated microfluidic device

    NASA Astrophysics Data System (ADS)

    Zhu, Jun; Cao, Ying; Wang, Hong; Li, Yigui; Chen, Xiang; Chen, Di

    2013-07-01

    Although microfluidic devices that integrate microfluidic chips with hollow out-of-plane microneedle arrays have many advantages in transdermal drug delivery applications, difficulties exist in their fabrication due to the special three-dimensional structures of hollow out-of-plane microneedles. A new, cost-effective process for the fabrication of a hollow out-of-plane Ni microneedle array is presented. The integration of PDMS microchips with the Ni hollow microneedle array and the properties of microfluidic devices are also presented. The integrated microfluidic devices provide a new approach for transdermal drug delivery.

  10. The HgI sub 2 energy dispersive x-ray array detectors and minaturized processing electronics project

    SciTech Connect

    Iwanczyk, J.S.; Dorri, N.; Wang, M.; Szawlowski . Inst. of Physics); Patt, W.K. ); Hedman, B.; Hodgson, K.O. . Stanford Synchrotron Radiation Lab.)

    1990-04-01

    This paper describes recent progress in the development of HgI{sub 2} energy dispersive x-ray detector arrays for synchrotron radiation research and their associated miniaturized processing electronics. Deploying a 5 element HgI{sub 2} array detector under realistic operating conditions at SSRL, an energy resolution of 252 eV FWHM at 5.9 keV (Mn-K{alpha}) was obtained. The authors also report energy resolution and throughput measurements versus input count rate. The results from the HgI{sub 2} system are then compared to those obtained under identical conditions from a commercial 13 element Ge detector array.

  11. SmartHEALTH: a microfluidic multisensor platform for POC cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Gärtner, Claudia; Becker, Holger; Carstens, Cornelia; von Germar, Frithjof; Drese, Klaus Stefan; Fragoso, Alex; Gransee, Rainer; Guber, Andreas; Herrmann, Dirk; Hlawatsch, Nadine; Klemm, Richard; Latta, Daniel; O'Sullivan, Ciara; Ruano-Lopez, Jesus

    2009-05-01

    A universal microfluidic platform as a multisensor device for cancer diagnostics, developed within the framework of the EU project SmartHEALTH [1], will be presented. Based on a standardization concept, a microfluidic platform was realized that contains various functional modules in order to allow in its final setup to run a complete diagnostic assay on a chip starting with sample preparation to a final detection via a sensor array. A twofold concept was pursued for the development and standardization: On the one hand, a standard footprint with defined areas for special functional elements was chosen, on the other hand a toolbox-approach [2] was used whereas in a first instance different functional fluidic modules were realized, evaluated and afterwards integrated into the microfluidic multisensor platform. One main characteristic of the platform is that different kind of sensors can be used with the same fluidic chip. For the read-out and fluidic control of the chip, common fluidic interfaces to the instrument were defined. This microfluidic consumable is a hybrid system consisting of a polymer component with an integrated sensor, reagent storage on chip, integrated valves and metering elements.

  12. Ultrasound nondestructive evaluation (NDE) imaging with transducer arrays and adaptive processing.

    PubMed

    Li, Minghui; Hayward, Gordon

    2012-01-01

    This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated.

  13. Range-dependent geoacoustic inversion of vertical line array data using matched beam processing.

    PubMed

    Kim, Kyungseop; Seong, Woojae; Lee, Keunhwa; Kim, Seongil; Shim, Taebo

    2009-02-01

    This paper describes the results of range-dependent geoacoustic inversion using vertical line array data obtained from the 4th Matched Acoustic Properties and Localization Experiment conducted in the East Sea of Korea. The narrowband multitone continuous-wave signal from the towed source was analyzed to estimate the range-dependent geoacoustic properties along the radial track. The primary approach is based on the sectorwise inversion scheme. The inversion region up to 7.5 km from the vertical line array was divided into several segments, and the subinversions for each segment were performed sequentially. To reduce the dominance of low-angle arrivals, which bears little information for the bottom segment in question, matched beam processing with beam filtering was used for the cost function. The performance of proposed algorithm was tested using simulated data for an environment representative of the experimental site. The inversion results for the experimental data were consistent with the geophysical database and were validated from matched-field source localization using frequencies different from those used in the inversion.

  14. Analysis of Deep Drawing Process for Stainless Steel Micro-Channel Array

    PubMed Central

    Chen, Tsung-Chia; Lin, Jiang-Cheng; Lee, Rong-Mao

    2017-01-01

    The stainless steel bipolar plate has received much attention due to the cost of graphite bipolar plates. Since the micro-channel of bipolar plates plays the role of fuel flow field, electric connector and fuel sealing, an investigation of the deep drawing process for stainless steel micro-channel arrays is reported in this work. The updated Lagrangian formulation, degenerated shell finite element analysis, and the r-minimum rule have been employed to study the relationship between punch load and stroke, distributions of stress and strain, thickness variations and depth variations of individual micro-channel sections. A micro-channel array is practically formed, with a width and depth of a single micro-channel of 0.75 mm and 0.5 mm, respectively. Fractures were usually observed in the fillet corner of the micro-channel bottom. According to the experimental results, more attention should be devoted to the fillet dimension design of punch and die. A larger die fillet can lead to better formability and a reduction of the punch load. In addition, the micro-channel thickness and the fillet radius have to be taken into consideration at the same time. Finally, the punch load estimated by the unmodified metal forming equation is higher than that of experiments. PMID:28772782

  15. Analysis of Deep Drawing Process for Stainless Steel Micro-Channel Array.

    PubMed

    Chen, Tsung-Chia; Lin, Jiang-Cheng; Lee, Rong-Mao

    2017-04-18

    The stainless steel bipolar plate has received much attention due to the cost of graphite bipolar plates. Since the micro-channel of bipolar plates plays the role of fuel flow field, electric connector and fuel sealing, an investigation of the deep drawing process for stainless steel micro-channel arrays is reported in this work. The updated Lagrangian formulation, degenerated shell finite element analysis, and the r-minimum rule have been employed to study the relationship between punch load and stroke, distributions of stress and strain, thickness variations and depth variations of individual micro-channel sections. A micro-channel array is practically formed, with a width and depth of a single micro-channel of 0.75 mm and 0.5 mm, respectively. Fractures were usually observed in the fillet corner of the micro-channel bottom. According to the experimental results, more attention should be devoted to the fillet dimension design of punch and die. A larger die fillet can lead to better formability and a reduction of the punch load. In addition, the micro-channel thickness and the fillet radius have to be taken into consideration at the same time. Finally, the punch load estimated by the unmodified metal forming equation is higher than that of experiments.

  16. Ultrasound Nondestructive Evaluation (NDE) Imaging with Transducer Arrays and Adaptive Processing

    PubMed Central

    Li, Minghui; Hayward, Gordon

    2012-01-01

    This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated. PMID:22368457

  17. Real-time processing for Fourier domain optical coherence tomography using a field programmable gate array

    NASA Astrophysics Data System (ADS)

    Ustun, Teoman E.; Iftimia, Nicusor V.; Ferguson, R. Daniel; Hammer, Daniel X.

    2008-11-01

    Real-time display of processed Fourier domain optical coherence tomography (FDOCT) images is important for applications that require instant feedback of image information, for example, systems developed for rapid screening or image-guided surgery. However, the computational requirements for high-speed FDOCT image processing usually exceeds the capabilities of most computers and therefore display rates rarely match acquisition rates for most devices. We have designed and developed an image processing system, including hardware based upon a field programmable gated array, firmware, and software that enables real-time display of processed images at rapid line rates. The system was designed to be extremely flexible and inserted in-line between any FDOCT detector and any Camera Link frame grabber. Two versions were developed for spectrometer-based and swept source-based FDOCT systems, the latter having an additional custom high-speed digitizer on the front end but using all the capabilities and features of the former. The system was tested in humans and monkeys using an adaptive optics retinal imager, in zebrafish using a dual-beam Doppler instrument, and in human tissue using a swept source microscope. A display frame rate of 27 fps for fully processed FDOCT images (1024 axial pixels×512 lateral A-scans) was achieved in the spectrometer-based systems.

  18. Full image-processing pipeline in field-programmable gate array for a small endoscopic camera

    NASA Astrophysics Data System (ADS)

    Mostafa, Sheikh Shanawaz; Sousa, L. Natércia; Ferreira, Nuno Fábio; Sousa, Ricardo M.; Santos, Joao; Wäny, Martin; Morgado-Dias, F.

    2017-01-01

    Endoscopy is an imaging procedure used for diagnosis as well as for some surgical purposes. The camera used for the endoscopy should be small and able to produce a good quality image or video, to reduce discomfort of the patients, and to increase the efficiency of the medical team. To achieve these fundamental goals, a small endoscopy camera with a footprint of 1 mm×1 mm×1.65 mm is used. Due to the physical properties of the sensors and human vision system limitations, different image-processing algorithms, such as noise reduction, demosaicking, and gamma correction, among others, are needed to faithfully reproduce the image or video. A full image-processing pipeline is implemented using a field-programmable gate array (FPGA) to accomplish a high frame rate of 60 fps with minimum processing delay. Along with this, a viewer has also been developed to display and control the image-processing pipeline. The control and data transfer are done by a USB 3.0 end point in the computer. The full developed system achieves real-time processing of the image and fits in a Xilinx Spartan-6LX150 FPGA.

  19. Real-time processing for Fourier domain optical coherence tomography using a field programmable gate array

    PubMed Central

    Ustun, Teoman E.; Iftimia, Nicusor V.; Ferguson, R. Daniel; Hammer, Daniel X.

    2008-01-01

    Real-time display of processed Fourier domain optical coherence tomography (FDOCT) images is important for applications that require instant feedback of image information, for example, systems developed for rapid screening or image-guided surgery. However, the computational requirements for high-speed FDOCT image processing usually exceeds the capabilities of most computers and therefore display rates rarely match acquisition rates for most devices. We have designed and developed an image processing system, including hardware based upon a field programmable gated array, firmware, and software that enables real-time display of processed images at rapid line rates. The system was designed to be extremely flexible and inserted in-line between any FDOCT detector and any Camera Link frame grabber. Two versions were developed for spectrometer-based and swept source-based FDOCT systems, the latter having an additional custom high-speed digitizer on the front end but using all the capabilities and features of the former. The system was tested in humans and monkeys using an adaptive optics retinal imager, in zebrafish using a dual-beam Doppler instrument, and in human tissue using a swept source microscope. A display frame rate of 27 fps for fully processed FDOCT images (1024 axial pixels×512 lateral A-scans) was achieved in the spectrometer-based systems. PMID:19045902

  20. Improving GPR Surveys Productivity by Array Technology and Fully Automated Processing

    NASA Astrophysics Data System (ADS)

    Morello, Marco; Ercoli, Emanuele; Mazzucchelli, Paolo; Cottino, Edoardo

    2016-04-01

    The realization of network infrastructures with lower environmental impact and the tendency to use digging technologies less invasive in terms of time and space of road occupation and restoration play a key-role in the development of communication networks. However, pre-existing buried utilities must be detected and located in the subsurface, to exploit the high productivity of modern digging apparatus. According to SUE quality level B+ both position and depth of subsurface utilities must be accurately estimated, demanding for 3D GPR surveys. In fact, the advantages of 3D GPR acquisitions (obtained either by multiple 2D recordings or by an antenna array) versus 2D acquisitions are well-known. Nonetheless, the amount of acquired data for such 3D acquisitions does not usually allow to complete processing and interpretation directly in field and in real-time, thus limiting the overall efficiency of the GPR acquisition. As an example, the "low impact mini-trench "technique (addressed in ITU - International Telecommunication Union - L.83 recommendation) requires that non-destructive mapping of buried services enhances its productivity to match the improvements of new digging equipment. Nowadays multi-antenna and multi-pass GPR acquisitions demand for new processing techniques that can obtain high quality subsurface images, taking full advantage of 3D data: the development of a fully automated and real-time 3D GPR processing system plays a key-role in overall optical network deployment profitability. Furthermore, currently available computing power suggests the feasibility of processing schemes that incorporate better focusing algorithms. A novel processing scheme, whose goal is the automated processing and detection of buried targets that can be applied in real-time to 3D GPR array systems, has been developed and fruitfully tested with two different GPR arrays (16 antennas, 900 MHz central frequency, and 34 antennas, 600 MHz central frequency). The proposed processing

  1. A hierarachical data structure representation for fusing multisensor information

    SciTech Connect

    Maren, A.J.; Pap, R.M.; Harston, C.T.

    1989-12-31

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  2. A hierarachical data structure representation for fusing multisensor information

    SciTech Connect

    Maren, A.J. . Space Inst.); Pap, R.M.; Harston, C.T. )

    1989-01-01

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  3. A hierarchical structure approach to MultiSensor Information Fusion

    SciTech Connect

    Maren, A.J. . Space Inst.); Pap, R.M.; Harston, C.T. )

    1989-01-01

    A major problem with image-based MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the pixel, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Pixel-level fusion has problems with coregistration of the images or data. Attempts to fuse information using the features of segmented images or data relies an a presumed similarity between the segmentation characteristics of each image or data stream. Symbolic-level fusion requires too much advance processing to be useful, as we have seen in automatic target recognition tasks. Image-based MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Scene Structure (HSS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The MSS is intermediate between a pixel-based representation and a scene interpretation representation, and represents the perceptual organization of an image. Fused HSSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based,region interpretation.

  4. A hierarchical structure approach to MultiSensor Information Fusion

    SciTech Connect

    Maren, A.J.; Pap, R.M.; Harston, C.T.

    1989-12-31

    A major problem with image-based MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the pixel, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Pixel-level fusion has problems with coregistration of the images or data. Attempts to fuse information using the features of segmented images or data relies an a presumed similarity between the segmentation characteristics of each image or data stream. Symbolic-level fusion requires too much advance processing to be useful, as we have seen in automatic target recognition tasks. Image-based MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Scene Structure (HSS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The MSS is intermediate between a pixel-based representation and a scene interpretation representation, and represents the perceptual organization of an image. Fused HSSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based,region interpretation.

  5. MTS in false positive reduction for multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Cudney, Elizabeth

    2014-05-01

    The Mahalanobis Taguchi System (MTS) is a relatively new tool in the vehicle health maintenance domain, but has some distinct advantages in current multi-sensor implementations. The use of Mahalanobis Spaces (MS) allows the algorithm to identify characteristics of sensor signals to identify behaviors in machines. MTS is extremely powerful with the caveat that the correct variables are selected to form the MS. In this research work, 56 sensors monitor various aspects of the vehicles. Typically, using the MTS process, identification of useful variables is preceded by validation of the measurements scale. However, the MTS approach doesn't directly include any mitigating steps should the measurement scale not be validated. Existing work has performed outlier removal in construction of the MS, which can lead to better validation. In our approach, we modify the outlier removal process with more liberal definitions of outliers to better identify variables' impact prior to identification of useful variables. This subtle change substantially lowered the false positive rate due to the fact that additional variables were retained. Traditional MTS approaches identify useful variables only to the extent they provide usefulness in identifying the positive (abnormal) condition. The impact of removing false negatives is not included. Initial results show our approach can reduce false positive values while still maintaining complete fault identification for this vehicle data set.

  6. Integrated multi-sensor package (IMSP) for unmanned vehicle operations

    NASA Astrophysics Data System (ADS)

    Crow, Eddie C.; Reichard, Karl; Rogan, Chris; Callen, Jeff; Seifert, Elwood

    2007-10-01

    This paper describes recent efforts to develop integrated multi-sensor payloads for small robotic platforms for improved operator situational awareness and ultimately for greater robot autonomy. The focus is on enhancements to perception through integration of electro-optic, acoustic, and other sensors for navigation and inspection. The goals are to provide easier control and operation of the robot through fusion of multiple sensor outputs, to improve interoperability of the sensor payload package across multiple platforms through the use of open standards and architectures, and to reduce integration costs by embedded sensor data processing and fusion within the sensor payload package. The solutions investigated in this project to be discussed include: improved capture, processing and display of sensor data from multiple, non-commensurate sensors; an extensible architecture to support plug and play of integrated sensor packages; built-in health, power and system status monitoring using embedded diagnostics/prognostics; sensor payload integration into standard product forms for optimized size, weight and power; and the use of the open Joint Architecture for Unmanned Systems (JAUS)/ Society of Automotive Engineers (SAE) AS-4 interoperability standard. This project is in its first of three years. This paper will discuss the applicability of each of the solutions in terms of its projected impact to reducing operational time for the robot and teleoperator.

  7. Integration of Multi-sensor Data for Desertification Monitoring

    NASA Astrophysics Data System (ADS)

    Lin, S.; Kim, J.

    2010-12-01

    dune activities can be clearly revealed. For the very detailed measurement, a terrestrial system applying close range photogrammetry will be set up in the test sites to acquire sequential images and used to generate 4D model of the dunes in future. Finally, all the outputs from the multi-sensor data will be crossly verified and compiled to model the desertification process and the consequences. A desertification combating activity which is performed by Korea-China NGO alliance has been conducted in Qubuqi desert in Nei Mongol, China. The method and system proposed above will be established and applied to monitor the dune mobility occurring in this area. The results are expected to be of great value to demonstrate the first case of remote sensing monitoring over the combat desertification activities.

  8. Multisensor technologies for low cost methane detection

    NASA Astrophysics Data System (ADS)

    Clifford, P. K.; Dorman, M. G.

    1988-11-01

    The study lays the technical foundation necessary to quantitatively characterize array performance and to determine the number of sensors needed for false-alarm-free methane detection. A technique was developed to quantitate the performances of sensor arrays. This technique was verified using data from a series of experiments that measured the responses of metal oxide semiconductor sensing arrays to methane and representative interfering gases, carbon monoxide and ammonia. Arrays of as few as two or three properly chosen sensors exhibit excellent immunity to false alarms. Further experiments show that arrays demonstrate good selectivity and low false alarm rates even after significant drift of sensor characteristics.

  9. A laser-assisted process to produce patterned growth of vertically aligned nanowire arrays for monolithic microwave integrated devices.

    PubMed

    Kerckhoven, Vivien Van; Piraux, Luc; Huynen, Isabelle

    2016-06-10

    An experimental process for the fabrication of microwave devices made of nanowire arrays embedded in a dielectric template is presented. A pulse laser process is used to produce a patterned surface mask on alumina templates, defining precisely the wire growing areas during electroplating. This technique makes it possible to finely position multiple nanowire arrays in the template, as well as produce large areas and complex structures, combining transmission line sections with various nanowire heights. The efficiency of this process is demonstrated through the realisation of a microstrip electromagnetic band-gap filter and a substrate-integrated waveguide.

  10. Enhanced Processing for a Towed Array Using an Optimal Noise Canceling Approach

    SciTech Connect

    Sullivan, E J; Candy, J V

    2005-07-21

    Noise self-generated by a surface ship towing an array in search of a weak target presents a major problem for the signal processing especially if broadband techniques are being employed. In this paper we discuss the development and application of an adaptive noise canceling processor capable of extracting the weak far-field acoustic target in a noisy ocean acoustic environment. The fundamental idea for this processor is to use a model-based approach incorporating both target and ship noise. Here we briefly describe the underlying theory and then demonstrate through simulation how effective the canceller and target enhancer perform. The adaptivity of the processor not only enables the ''tracking'' of the canceller coefficients, but also the estimation of target parameters for localization. This approach which is termed ''joint'' cancellation and enhancement produces the optimal estimate of both in a minimum (error) variance sense.

  11. A field-programmable analog array development platform for vestibular prosthesis signal processing.

    PubMed

    Töreyin, Hakan; Bhatti, Pamela

    2013-06-01

    We report on a vestibular prosthesis signal processor realized using an experimental field programmable analog array (FPAA). Completing signal processing functions in the analog domain, the processor is designed to help replace a malfunctioning inner ear sensory organ, a semicircular canal. Relying on angular head motion detected by an inertial sensor, the signal processor maps angular velocity into meaningful control signals to drive a current stimulator. To demonstrate biphasic pulse control a 1 k Ω resistive load was placed across an H-bridge circuit. When connected to a 2.4 V supply, a biphasic current of 100 μA was maintained at stimulation frequencies from 50-350 Hz, pulsewidths from 25-400 μ sec, and interphase gaps ranging from 25-250 μsec.

  12. A Field-Programmable Analog Array Development Platform for Vestibular Prosthesis Signal Processing

    PubMed Central

    Töreyin, Hakan; Bhatti, Pamela

    2015-01-01

    We report on a vestibular prosthesis signal processor realized using an experimental field programmable analog array (FPAA). Completing signal processing functions in the analog domain, the processor is designed to help replace a malfunctioning inner ear sensory organ, a semicircular canal. Relying on angular head motion detected by an inertial sensor, the signal processor maps angular velocity into meaningful control signals to drive a current stimulator. To demonstrate biphasic pulse control a 1 kΩ resistive load was placed across an H-bridge circuit. When connected to a 2.4 V supply, a biphasic current of 100 μA was maintained at stimulation frequencies from 50–350 Hz, pulsewidths from 25–400 μsec, and interphase gaps ranging from 25–250 sec. PMID:23853331

  13. Statistical Analysis of the Performance of MDL Enumeration for Multiple-Missed Detection in Array Processing

    PubMed Central

    Du, Fei; Li, Yibo; Jin, Shijiu

    2015-01-01

    An accurate performance analysis on the MDL criterion for source enumeration in array processing is presented in this paper. The enumeration results of MDL can be predicted precisely by the proposed procedure via the statistical analysis of the sample eigenvalues, whose distributive properties are investigated with the consideration of their interactions. A novel approach is also developed for the performance evaluation when the source number is underestimated by a number greater than one, which is denoted as “multiple-missed detection”, and the probability of a specific underestimated source number can be estimated by ratio distribution analysis. Simulation results are included to demonstrate the superiority of the presented method over available results and confirm the ability of the proposed approach to perform multiple-missed detection analysis. PMID:26295232

  14. Statistical Analysis of the Performance of MDL Enumeration for Multiple-Missed Detection in Array Processing.

    PubMed

    Du, Fei; Li, Yibo; Jin, Shijiu

    2015-08-18

    An accurate performance analysis on the MDL criterion for source enumeration in array processing is presented in this paper. The enumeration results of MDL can be predicted precisely by the proposed procedure via the statistical analysis of the sample eigenvalues, whose distributive properties are investigated with the consideration of their interactions. A novel approach is also developed for the performance evaluation when the source number is underestimated by a number greater than one, which is denoted as "multiple-missed detection", and the probability of a specific underestimated source number can be estimated by ratio distribution analysis. Simulation results are included to demonstrate the superiority of the presented method over available results and confirm the ability of the proposed approach to perform multiple-missed detection analysis.

  15. Efficient architecture for a multichannel array subbanding system with adaptive processing

    NASA Astrophysics Data System (ADS)

    Rabinkin, Daniel V.; Nguyen, Huy T.

    2000-11-01

    An architecture is presented for front-end processing in a wideband array system which samples real signals. Such a system may be encountered in cellular telephony, radar, or low SNR digital communications receivers. The subbanding of data enables system data rate reduction, and creates a narrowband condition for adaptive processing within the subbands. The front-end performs passband filtering, equalization, subband decomposition and adaptive beamforming. The subbanding operation is efficiently implemented using a prototype lowpass finite impulse response (FIR) filter, decomposed into polyphase form, combined with a Fast Fourier Transform (FFT) block and a bank of modulating postmultipliers. If the system acquires real inputs, a single FFT may be used to operate on two channels, but a channel separation network is then required for recovery of individual channel data. A sequence of steps is described based on data transformation techniques that enables a maximally efficient implementation of the processing stages and eliminates the need for channel separation. Operation count is reduced, and several layers of processing are eliminated.

  16. Magnetic alloy nanowire arrays with different lengths: Insights into the crossover angle of magnetization reversal process

    NASA Astrophysics Data System (ADS)

    Samanifar, S.; Alikhani, M.; Almasi Kashi, M.; Ramazani, A.; Montazer, A. H.

    2017-05-01

    Nanoscale magnetic alloy wires are being actively investigated, providing fundamental insights into tuning properties in magnetic data storage and processing technologies. However, previous studies give trivial information about the crossover angle of magnetization reversal process in alloy nanowires (NWs). Here, magnetic alloy NW arrays with different compositions, composed of Fe, Co and Ni have been electrochemically deposited into hard-anodic aluminum oxide templates with a pore diameter of approximately 150 nm. Under optimized conditions of alumina barrier layer and deposition bath concentrations, the resulting alloy NWs with aspect ratio and saturation magnetization (Ms) up to 550 and 1900 emu cm-3, respectively, are systematically investigated in terms of composition, crystalline structure and magnetic properties. Using angular dependence of coercivity extracted from hysteresis loops, the reversal processes are evaluated, indicating non-monotonic behavior. The crossover angle (θc) is found to depend on NW length and Ms. At a constant Ms, increasing NW length decreases θc, thereby decreasing the involvement of vortex mode during the magnetization reversal process. On the other hand, decreasing Ms decreases θc in large aspect ratio (>300) alloy NWs. Phenomenologically, it is newly found that increasing Ni content in the composition decreases θc. The angular first-order reversal curve (AFORC) measurements including the irreversibility of magnetization are also investigated to gain a more detailed insight into θc.

  17. Optoelectronic parallel processing with smart pixel arrays for automated screening of cervical smear imagery

    NASA Astrophysics Data System (ADS)

    Metz, John Langdon

    2000-10-01

    This thesis investigates the use of optoelectronic parallel processing systems with smart photosensor arrays (SPAs) to examine cervical smear images. The automation of cervical smear screening seeks to reduce human workload and improve the accuracy of detecting pre- cancerous and cancerous conditions. Increasing the parallelism of image processing improves the speed and accuracy of locating regions-of-interest (ROI) from images of the cervical smear for the first stage of a two-stage screening system. The two-stage approach first detects ROI optoelectronically before classifying them using more time consuming electronic algorithms. The optoelectronic hit/miss transform (HMT) is computed using gray scale modulation spatial light modulators in an optical correlator. To further the parallelism of this system, a novel CMOS SPA computes the post processing steps required by the HMT algorithm. The SPA reduces the subsequent bandwidth passed into the second, electronic image processing stage classifying the detected ROI. Limitations in the miss operation of the HMT suggest using only the hit operation for detecting ROI. This makes possible a single SPA chip approach using only the hit operation for ROI detection which may replace the optoelectronic correlator in the screening system. Both the HMT SPA postprocessor and the SPA ROI detector design provide compact, efficient, and low-cost optoelectronic solutions to performing ROI detection on cervical smears. Analysis of optoelectronic ROI detection with electronic ROI classification shows these systems have the potential to perform at, or above, the current error rates for manual classification of cervical smears.

  18. Alternative post-processing on a CMOS chip to fabricate a planar microelectrode array.

    PubMed

    López-Huerta, Francisco; Herrera-May, Agustín L; Estrada-López, Johan J; Zuñiga-Islas, Carlos; Cervantes-Sanchez, Blanca; Soto, Enrique; Soto-Cruz, Blanca S

    2011-01-01

    We present an alternative post-processing on a CMOS chip to release a planar microelectrode array (pMEA) integrated with its signal readout circuit, which can be used for monitoring the neuronal activity of vestibular ganglion neurons in newborn Wistar strain rats. This chip is fabricated through a 0.6 μm CMOS standard process and it has 12 pMEA through a 4 × 3 electrodes matrix. The alternative CMOS post-process includes the development of masks to protect the readout circuit and the power supply pads. A wet etching process eliminates the aluminum located on the surface of the p+ -type silicon. This silicon is used as transducer for recording the neuronal activity and as interface between the readout circuit and neurons. The readout circuit is composed of an amplifier and tunable bandpass filter, which is placed on a 0.015 mm2 silicon area. The tunable bandpass filter has a bandwidth of 98 kHz and a common mode rejection ratio (CMRR) of 87 dB. These characteristics of the readout circuit are appropriate for neuronal recording applications.

  19. Alternative Post-Processing on a CMOS Chip to Fabricate a Planar Microelectrode Array

    PubMed Central

    López-Huerta, Francisco; Herrera-May, Agustín L.; Estrada-López, Johan J.; Zuñiga-Islas, Carlos; Cervantes-Sanchez, Blanca; Soto, Enrique; Soto-Cruz, Blanca S.

    2011-01-01

    We present an alternative post-processing on a CMOS chip to release a planar microelectrode array (pMEA) integrated with its signal readout circuit, which can be used for monitoring the neuronal activity of vestibular ganglion neurons in newborn Wistar strain rats. This chip is fabricated through a 0.6 μm CMOS standard process and it has 12 pMEA through a 4 × 3 electrodes matrix. The alternative CMOS post-process includes the development of masks to protect the readout circuit and the power supply pads. A wet etching process eliminates the aluminum located on the surface of the p+-type silicon. This silicon is used as transducer for recording the neuronal activity and as interface between the readout circuit and neurons. The readout circuit is composed of an amplifier and tunable bandpass filter, which is placed on a 0.015 mm2 silicon area. The tunable bandpass filter has a bandwidth of 98 kHz and a common mode rejection ratio (CMRR) of 87 dB. These characteristics of the readout circuit are appropriate for neuronal recording applications. PMID:22346681

  20. Multisensor based robotic manipulation in an uncalibrated manufacturing workcell

    SciTech Connect

    Ghosh, B.K.; Xiao, Di; Xi, Ning; Tarn, Tzyh-Jong

    1997-12-31

    The main problem that we address in this paper is how a robot manipulator is able to track and grasp a part placed arbitrarily on a moving disc conveyor aided by a single CCD camera and fusing information from encoders placed on the conveyor and also from encoders on the robot manipulator. The important assumption that distinguishes our work from what has been previously reported in the literature is that the position and orientation of the camera and the base frame of the robot is apriori assumed to be unknown and is `visually calibrated` during the operation of the manipulator. Moreover the part placed on the conveyor is assumed to be non-planar, i.e. the feature points observed on the part is assumed to be located arbitrarily in IR{sup 3}. The novelties of the proposed approach in this paper includes a (i) multisensor fusion scheme based on complementary data for the purpose of part localization, and (ii) self-calibration between the turntable and the robot manipulator using visual data and feature points on the end-effector. The principle advantages of the proposed scheme are the following. (i) It renders possible to reconfigure a manufacturing workcell without recalibrating the relation between the turntable and the robot. This significantly shortens the setup time of the workcell. (ii) It greatly weakens the requirement on the image processing speed.

  1. Adaptive multi-sensor integration for mine detection

    SciTech Connect

    Baker, J.E.

    1997-05-01

    State-of-the-art in multi-sensor integration (MSI) application involves extensive research and development time to understand and characterize the application domain; to determine and define the appropriate sensor suite; to analyze, characterize, and calibrate the individual sensor systems; to recognize and accommodate the various sensor interactions; and to develop and optimize robust merging code. Much of this process can benefit from adaptive learning, i.e., an output-based system can take raw sensor data and desired merged results as input and adaptively develop/determine an effective method if interpretation and merger. This approach significantly reduces the time required to apply MSI to a given application, while increasing the quality of the final result and provides a quantitative measure for comparing competing MSI techniques and sensor suites. The ability to automatically develop and optimize MSI techniques for new sensor suites and operating environments makes this approach well suited to the detection of mines and mine-like targets. Perhaps more than any other, this application domain is characterized by diverse, innovative, and dynamic sensor suites, whose nature and interactions are not yet well established. This paper presents such an outcome-based multi-image analysis system. An empirical evaluation of its performance and its application, sensor and domain robustness is presented.

  2. Multisensor Systems and Floods Risk Management in the Danube Delta

    NASA Astrophysics Data System (ADS)

    Niculescu, Simona; Guttler, Fabio Nor; Lardeux, Cedric; Rudant, Jean-Paul

    2008-11-01

    The use of multisensor systems, such as radar and hyperspectral imagers, and digital elevation models (DEM) derived from LIDAR, contribute to a better comprehension of floods in the Danube Delta, their impacts, and risk management and sustainable development in the delta. This paper presents the processing of Advanced Synthetic Aperture Radar images, in C band and vertical polarization, for mapping flooded and floodable areas during the events of spring 2006 in the Danube Delta. Although radar imagery provides important and precise information on the location and characterization of flooded and floodable areas, and on essential areas in the land settlement of the territory that belongs to the administrators and the delta population, this instrument quickly shows its limits. In order to characterize floodable zones, complementary hyperspectral images from the CHRIS/PROBA sensor were analyzed, thus restoring accurate details of vegetation surfaces in this humid zone. Some correlations between the social and economic aspects of this vegetation stratum and their flood potential, according to different forms of agricultural practices, were established. Watermark estimation during the events of 2006 were drawn by merging the data with Lidar measurements taken during the 2007 campaign all over the Danube valley in the Romanian sector (with a precision of about 15 to 30 cm).

  3. Dynamic algorithm selection for multi-sensor image registration

    NASA Astrophysics Data System (ADS)

    DelMarco, Stephen; Tom, Victor; Webb, Helen; Lefebvre, David

    2009-05-01

    Modern sensors have a range of modalities including SAR, EO, and IR. Registration of multimodal imagery from such sensors is becoming an increasingly common pre-processing step for various image exploitation activities such as image fusion for ATR. Over the past decades, several approaches to multisensor image registration have been developed. However, performance of these image registration algorithms is highly dependent on scene content and sensor operating conditions, with no single algorithm working well across the entire operating conditions space. To address this problem, in this paper we present an approach for dynamic selection of an appropriate registration algorithm, tuned to the scene content and feature manifestation of the imagery under consideration. We consider feature-based registration using Harris corners, Canny edge detection, and CFAR features, as well as pixel-based registration using cross-correlation and mutual information. We develop an approach for selecting the optimal combination of algorithms to use in the dynamic selection algorithm. We define a performance measure which balances contributions from convergence redundancy and convergence coverage components calculated over sample imagery, and optimize the measure to define an optimal algorithm set. We present numerical results demonstrating the improvement in registration performance through use of the dynamic algorithm selection approach over results generated through use of a fixed registration algorithm approach. The results provide registration convergence probabilities for geo-registering test SAR imagery against associated EO reference imagery. We present convergence results for various match score normalizations used in the dynamic selection algorithm.

  4. Fabrication of dense non-circular nanomagnetic device arrays using self-limiting low-energy glow-discharge processing.

    PubMed

    Zheng, Zhen; Chang, Long; Nekrashevich, Ivan; Ruchhoeft, Paul; Khizroev, Sakhrat; Litvinov, Dmitri

    2013-01-01

    We describe a low-energy glow-discharge process using reactive ion etching system that enables non-circular device patterns, such as squares or hexagons, to be formed from a precursor array of uniform circular openings in polymethyl methacrylate, PMMA, defined by electron beam lithography. This technique is of a particular interest for bit-patterned magnetic recording medium fabrication, where close packed square magnetic bits may improve its recording performance. The process and results of generating close packed square patterns by self-limiting low-energy glow-discharge are investigated. Dense magnetic arrays formed by electrochemical deposition of nickel over self-limiting formed molds are demonstrated.

  5. Fabrication of an array-like freeform molding tool for UV-replication using a step and repeat process

    NASA Astrophysics Data System (ADS)

    Dunkel, J.; Wippermann, F.; Brückner, A.; Reimann, A.; Bräuer, A.

    2013-05-01

    Artificial compound eye cameras are a prominent approach of next generation wafer level cameras for consumer electronics due to their lower z-height compared to conventional single aperture objectives. In order to address low cost and high volume markets, their fabrication is based on a wafer level UV-replication process. The image quality of compound eye cameras can be increased significantly by the use of refractive freeform arrays (RFFA) instead of conventional microlens arrays. Therefore, we present the fabrication of a RFFA wafer level molding tool by a step and repeat process for the first time. The surface qualities of the fabricated structures were characterized with a white light interferometer.

  6. An Integrated Model for Robust Multisensor Data Fusion

    PubMed Central

    Shen, Bo; Liu, Yun; Fu, Jun-Song

    2014-01-01

    This paper presents an integrated model aimed at obtaining robust and reliable results in decision level multisensor data fusion applications. The proposed model is based on the connection of Dempster-Shafer evidence theory and an extreme learning machine. It includes three main improvement aspects: a mass constructing algorithm to build reasonable basic belief assignments (BBAs); an evidence synthesis method to get a comprehensive BBA for an information source from several mass functions or experts; and a new way to make high-precision decisions based on an extreme learning machine (ELM). Compared to some universal classification methods, the proposed one can be directly applied in multisensor data fusion applications, but not only for conventional classifications. Experimental results demonstrate that the proposed model is able to yield robust and reliable results in multisensor data fusion problems. In addition, this paper also draws some meaningful conclusions, which have significant implications for future studies. PMID:25340445

  7. Real-time multi-sensor based vehicle detection using MINACE filters

    NASA Astrophysics Data System (ADS)

    Topiwala, Pankaj; Nehemiah, Avinash

    2007-04-01

    A system to detect vehicles (cars, trucks etc) in electro-optic (EO) and infrared (IR) imagery is presented. We present the use of the minimum noise and correlation (MINACE) distortion invariant filter (DIF) for this problem. The selection of the MINACE filter parameter c is automated using a training and validation set. A new set of correlation plane post processing methods that improve detection accuracies and reduce false alarms are presented. The system is tested on real life imagery of traffic in parking lots and roads obtained using a multi-sensor EO/IR platform.

  8. A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation.

    PubMed

    Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-Hong; Zhang, Hong; Sun, Mingui

    2015-04-01

    In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle.

  9. A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation

    PubMed Central

    Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-hong; Zhang, Hong; Sun, Mingui

    2015-01-01

    In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle. PMID:26185409

  10. Multi-Sensor Aerosol Products Sampling System

    NASA Technical Reports Server (NTRS)

    Petrenko, M.; Ichoku, C.; Leptoukh, G.

    2011-01-01

    Global and local properties of atmospheric aerosols have been extensively observed and measured using both spaceborne and ground-based instruments, especially during the last decade. Unique properties retrieved by the different instruments contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. However, some of these measurements remain underutilized, largely due to the complexities involved in analyzing them synergistically. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have established a Multi-sensor Aerosol Products Sampling System (MAPSS), which consistently samples and generates the spatial statistics (mean, standard deviation, direction and rate of spatial variation, and spatial correlation coefficient) of aerosol products from multiple spacebome sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS. Samples of satellite aerosol products are extracted over Aerosol Robotic Network (AERONET) locations as well as over other locations of interest such as those with available ground-based aerosol observations. In this way, MAPSS enables a direct cross-characterization and data integration between Level-2 aerosol observations from multiple sensors. In addition, the available well-characterized co-located ground-based data provides the basis for the integrated validation of these products. This paper explains the sampling methodology and concepts used in MAPSS, and demonstrates specific examples of using MAPSS for an integrated analysis of multiple aerosol products.

  11. Investigation of Proposed Process Sequence for the Array Automated Assembly Task, Phase 2. [low cost silicon solar array fabrication

    NASA Technical Reports Server (NTRS)

    Mardesich, N.; Garcia, A.; Bunyan, S.; Pepe, A.

    1979-01-01

    The technological readiness of the proposed process sequence was reviewed. Process steps evaluated include: (1) plasma etching to establish a standard surface; (2) forming junctions by diffusion from an N-type polymeric spray-on source; (3) forming a p+ back contact by firing a screen printed aluminum paste; (4) forming screen printed front contacts after cleaning the back aluminum and removing the diffusion oxide; (5) cleaning the junction by a laser scribe operation; (6) forming an antireflection coating by baking a polymeric spray-on film; (7) ultrasonically tin padding the cells; and (8) assembling cell strings into solar circuits using ethylene vinyl acetate as an encapsulant and laminating medium.

  12. Reduction of mine suspected areas by multisensor airborne measurements: first results

    NASA Astrophysics Data System (ADS)

    Keller, Martin; Milisavljevic, Nada; Suess, Helmut; Acheroy, Marc P. J.

    2002-08-01

    Humanitarian demining is a very dangerous, cost and time intensive work, where a lot of effort is usually wasted in inspecting suspected areas that turn out to be mine-free. The main goal of the project SMART (Space and airborne Mined Area Reduction Tools) is to apply a multisensor approach towards corresponding signature data collection, developing adapted data understanding and data processing tools for improving the efficiency and reliability of level 1 minefield surveys by reducing suspected mined areas. As a result, the time for releasing mine-free areas for civilian use should be shortened. In this paper, multisensor signature data collected at four mine suspected areas in different parts of Croatia are presented, their information content is discussed, and first results are described. The multisensor system consists of a multifrequency multipolarization SAR system (DLR Experimental Synthetic Aperture Radar E-SAR), an optical scanner (Daedalus) and a camera (RMK) for color infrared aerial views. E-SAR data were acquired in X-, C-, L- and P- bands, the latter two being fully polarimetric interferometric. This provides pieces of independent information, ranging from high spatial resolution (X-band) to very good penetration abilities (P-band), together with possibilities for polarimetric and interferometric analysis. The Daedalus scanner, with 12 channels between visible and thermal infrared, has a very high spatial resolution. For each of the sensors, the applied processing, geocoding and registration is described. The information content is analyzed in sense of the capability and reliability in describing conditions inside suspected mined areas, as a first step towards identifying their mine-free parts, with special emphasis set on polarimetric and interferometric information.

  13. An SOI CMOS-Based Multi-Sensor MEMS Chip for Fluidic Applications.

    PubMed

    Mansoor, Mohtashim; Haneef, Ibraheem; Akhtar, Suhail; Rafiq, Muhammad Aftab; De Luca, Andrea; Ali, Syed Zeeshan; Udrea, Florin

    2016-11-04

    An SOI CMOS multi-sensor MEMS chip, which can simultaneously measure temperature, pressure and flow rate, has been reported. The multi-sensor chip has been designed keeping in view the requirements of researchers interested in experimental fluid dynamics. The chip contains ten thermodiodes (temperature sensors), a piezoresistive-type pressure sensor and nine hot film-based flow rate sensors fabricated within the oxide layer of the SOI wafers. The silicon dioxide layers with embedded sensors are relieved from the substrate as membranes with the help of a single DRIE step after chip fabrication from a commercial CMOS foundry. Very dense sensor packing per unit area of the chip has been enabled by using technologies/processes like SOI, CMOS and DRIE. Independent apparatuses were used for the characterization of each sensor. With a drive current of 10 µA-0.1 µA, the thermodiodes exhibited sensitivities of 1.41 mV/°C-1.79 mV/°C in the range 20-300 °C. The sensitivity of the pressure sensor was 0.0686 mV/(Vexcit kPa) with a non-linearity of 0.25% between 0 and 69 kPa above ambient pressure. Packaged in a micro-channel, the flow rate sensor has a linearized sensitivity of 17.3 mV/(L/min)(-0.1) in the tested range of 0-4.7 L/min. The multi-sensor chip can be used for simultaneous measurement of fluid pressure, temperature and flow rate in fluidic experiments and aerospace/automotive/biomedical/process industries.

  14. An SOI CMOS-Based Multi-Sensor MEMS Chip for Fluidic Applications †

    PubMed Central

    Mansoor, Mohtashim; Haneef, Ibraheem; Akhtar, Suhail; Rafiq, Muhammad Aftab; De Luca, Andrea; Ali, Syed Zeeshan; Udrea, Florin

    2016-01-01

    An SOI CMOS multi-sensor MEMS chip, which can simultaneously measure temperature, pressure and flow rate, has been reported. The multi-sensor chip has been designed keeping in view the requirements of researchers interested in experimental fluid dynamics. The chip contains ten thermodiodes (temperature sensors), a piezoresistive-type pressure sensor and nine hot film-based flow rate sensors fabricated within the oxide layer of the SOI wafers. The silicon dioxide layers with embedded sensors are relieved from the substrate as membranes with the help of a single DRIE step after chip fabrication from a commercial CMOS foundry. Very dense sensor packing per unit area of the chip has been enabled by using technologies/processes like SOI, CMOS and DRIE. Independent apparatuses were used for the characterization of each sensor. With a drive current of 10 µA–0.1 µA, the thermodiodes exhibited sensitivities of 1.41 mV/°C–1.79 mV/°C in the range 20–300 °C. The sensitivity of the pressure sensor was 0.0686 mV/(Vexcit kPa) with a non-linearity of 0.25% between 0 and 69 kPa above ambient pressure. Packaged in a micro-channel, the flow rate sensor has a linearized sensitivity of 17.3 mV/(L/min)−0.1 in the tested range of 0–4.7 L/min. The multi-sensor chip can be used for simultaneous measurement of fluid pressure, temperature and flow rate in fluidic experiments and aerospace/automotive/biomedical/process industries. PMID:27827904

  15. Biologically inspired large scale chemical sensor arrays and embedded data processing

    NASA Astrophysics Data System (ADS)

    Marco, S.; Gutiérrez-Gálvez, A.; Lansner, A.; Martinez, D.; Rospars, J. P.; Beccherelli, R.; Perera, A.; Pearce, T.; Vershure, P.; Persaud, K.

    2013-05-01

    Biological olfaction outperforms chemical instrumentation in specificity, response time, detection limit, coding capacity, time stability, robustness, size, power consumption, and portability. This biological function provides outstanding performance due, to a large extent, to the unique architecture of the olfactory pathway, which combines a high degree of redundancy, an efficient combinatorial coding along with unmatched chemical information processing mechanisms. The last decade has witnessed important advances in the understanding of the computational primitives underlying the functioning of the olfactory system. EU Funded Project NEUROCHEM (Bio-ICT-FET- 216916) has developed novel computing paradigms and biologically motivated artefacts for chemical sensing taking inspiration from the biological olfactory pathway. To demonstrate this approach, a biomimetic demonstrator has been built featuring a large scale sensor array (65K elements) in conducting polymer technology mimicking the olfactory receptor neuron layer, and abstracted biomimetic algorithms have been implemented in an embedded system that interfaces the chemical sensors. The embedded system integrates computational models of the main anatomic building blocks in the olfactory pathway: the olfactory bulb, and olfactory cortex in vertebrates (alternatively, antennal lobe and mushroom bodies in the insect). For implementation in the embedded processor an abstraction phase has been carried out in which their processing capabilities are captured by algorithmic solutions. Finally, the algorithmic models are tested with an odour robot with navigation capabilities in mixed chemical plumes

  16. The nonuniformity measurement and image processing algorithm evaluation for uncooled microbolometer infrared focal plane arrays

    NASA Astrophysics Data System (ADS)

    Qian, Yunsheng; Chang, BenKang; Zhang, Junju; Xing, Suxia; Yu, Shuizhong; Yang, Ji

    2005-01-01

    The great achievements were achieved in the manufacturing of uncooled microbolometer infrared focal plane arrays(UFPA). By this technique infrared system can be made in the formation of small volume, light weight, low price and being portable. It promotes greatly the utilization of infrared system in many fields. The main disadvantage of UFPA is non-uniformity. Despite non-uniformity of UFPA has been greatly improved, non-uniformity still restricts the performance of uncooled infrared system. In this paper, the attention is focused on the technology and methods measuring the non-uniformity of UFPA. The system that can measure the non-uniformity of UFPA and evaluate the image processing algorithms is developed. The measurement system consists of blackbody, infrared optics, control units, processing circuit, high-speed A/D converter, computer and software. To obtain the output signals of UFPA, the drive circuit and control circuit of thermoelectric stabilizer(TEC) of UFPA are developed. In the drive circuit, the CPLD device is employed to insure a small size circuit. In the TEC circuit, a kind of highly integrated and cost-effective, high-effiency, switch-mode driver is used to insure temperature stability of 0.01°C. The system is used to measure non-uniformity of microbolometer detectors which are produced by ULIS company. It can also present the evaluation of algorithm. The results are given and analyzed.

  17. Preconditioning of real-time optical Wiener filters for array processing

    NASA Astrophysics Data System (ADS)

    Ghosh, Anjan; Paparao, Palacharla

    1992-07-01

    In adaptive array processors, a performance measure, such as mean square error or signal to noise ration, coverages to the optimum Wiener solution starting from an initial setting. The choice of adaptive algorithms to solve the Wiener filtering problem is mainly guided by the desired processing time. In an optical realization for direct calculation of the optimum weights the covariance matrix and vector for a Wiener filter are computed at a high speed on acousto-optic processors. The resulting linear system of equations can be solved on an iterative optical processor. The matrix and vector data should be recomputed in every iteration for better tracking and adaptation. This introduces variations in their values due to the time-varying jamming and interference noise and the optical errors and noise. Time variant steepest descent algorithm is a simple method that converges to the common solution. In this paper, we describe a real-time preconditioning technique for such nonstationary iterative methods. Preconditioning will progressively lower the condition number of each matrix in the sequence, thereby improving the convergence speed and accuracy of the solution. This preconditioning process involves matrix-matrix multiplications that can be performed at high speed on parallel optical processors. Results of simulations illustrate the superlinear convergence obtained from preconditioning.

  18. A fast processing route of aspheric polydimethylsiloxane lenses array (APLA) and optical characterization for smartphone microscopy

    NASA Astrophysics Data System (ADS)

    Fuh, Yiin-Kuen; Lai, Zheng-Hong

    2017-02-01

    A fast processing route of aspheric polydimethylsiloxane (PDMS) lenses array (APLA) is proposed via the combined effect of inverted gravitational and heat-assisted forces. The fabrication time can be dramatically reduced to 30 s, compared favorably to the traditional duration of 2 hours of repeated cycles of addition-curing processes. In this paper, a low-cost flexible lens can be fabricated by repeatedly depositing, inverting, curing a hanging transparent PDMS elastomer droplet on a previously deposited curved structure. Complex structures with aspheric curve features and various focal lengths can be successfully produced and the fabricated 4 types of APLA have various focal lengths in the range of 7.03 mm, 6.00 mm, 5.33 mm, and 4.43 mm, respectively. Empirically, a direct relationship between the PDMS volume and focal lengths of the lenses can be experimentally deducted. Using these fabricated APLA, an ordinary commercial smartphone camera can be easily transformed to a low-cost, portable digital microscopy (50×magnification) such that point of care diagnostic can be implemented pervasively.

  19. Characterization of electrothermal actuators and arrays fabricated in a four-level, planarized surface-micromachined polycrystalline silicon process

    SciTech Connect

    Comtois, J.H.; Michalicek, M.A.; Barron, C.C.

    1997-06-01

    This paper presents the results of tests performed on a variety of electrothermal microactuators and arrays of these actuators recently fabricated in the four-level planarized polycrystalline silicon (polysilicon) SUMMiT process at the U.S. Department of Energy`s Sandia National Laboratories. These results are intended to aid designers of thermally actuated mechanisms, and will apply to similar actuators made in other polysilicon MEMS processes. The measurements include force and deflection versus input power, maximum operating frequency, effects of long term operation, and ideal actuator and array geometries for different design criteria. A typical application in a stepper motor is shown to illustrate the utility of these actuators and arrays.

  20. Thermal nanoimprint process for high-temperature fabrication of mesoscale epitaxial exchange-biased metallic wire arrays

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Weiss, D. N.; Krishnan, K. M.

    2011-04-01

    A thermal nanoimprint process for the high-temperature (400 °C) fabrication of submicron, epitaxial, metallic wire arrays over areas > 1 × 1 cm2 is reported. Based on a method using an imprinted polymeric bilayer resist template that is transferred to a metallic (molybdenum) mask, this process is enabled by an appropriate undercut profile of the Mo mask. The undercut profile is obtained from a distinctive wedge-shaped profile of the polymeric resist layers by carefully controlling the etch parameters. Using flexible ethylene tetrafluoroethylene imprint molds, we demonstrate defect-free imprinting on MgO substrates. Epitaxial patterning is demonstrated with Fe/MnPd bilayer wire arrays subsequently grown along well-defined crystallographic orientations. X-ray diffraction of the patterned arrays reveals that the MnPd can be grown in two different crystallographic orientations (c-axis and a-axis normals). The epitaxial nature of the patterned arrays is further confirmed by magnetic measurements that demonstrate the competing effects of intrinsic (magnetocrystalline and exchange) and lithography-induced shape anisotropies on the magnetization reversal characteristics along different directions with respect to the axis of the wire arrays.

  1. Comparison of Frequency-Domain Array Methods for Studying Earthquake Rupture Process

    NASA Astrophysics Data System (ADS)

    Sheng, Y.; Yin, J.; Yao, H.

    2014-12-01

    Seismic array methods, in both time- and frequency- domains, have been widely used to study the rupture process and energy radiation of earthquakes. With better spatial resolution, the high-resolution frequency-domain methods, such as Multiple Signal Classification (MUSIC) (Schimdt, 1986; Meng et al., 2011) and the recently developed Compressive Sensing (CS) technique (Yao et al., 2011, 2013), are revealing new features of earthquake rupture processes. We have performed various tests on the methods of MUSIC, CS, minimum-variance distortionless response (MVDR) Beamforming and conventional Beamforming in order to better understand the advantages and features of these methods for studying earthquake rupture processes. We use the ricker wavelet to synthesize seismograms and use these frequency-domain techniques to relocate the synthetic sources we set, for instance, two sources separated in space but, their waveforms completely overlapping in the time domain. We also test the effects of the sliding window scheme on the recovery of a series of input sources, in particular, some artifacts that are caused by the sliding window scheme. Based on our tests, we find that CS, which is developed from the theory of sparsity inversion, has relatively high spatial resolution than the other frequency-domain methods and has better performance at lower frequencies. In high-frequency bands, MUSIC, as well as MVDR Beamforming, is more stable, especially in the multi-source situation. Meanwhile, CS tends to produce more artifacts when data have poor signal-to-noise ratio. Although these techniques can distinctly improve the spatial resolution, they still produce some artifacts along with the sliding of the time window. Furthermore, we propose a new method, which combines both the time-domain and frequency-domain techniques, to suppress these artifacts and obtain more reliable earthquake rupture images. Finally, we apply this new technique to study the 2013 Okhotsk deep mega earthquake

  2. Planarized process for resonant leaky-wave coupled phase-locked arrays of mid-IR quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Chang, C.-C.; Kirch, J. D.; Boyle, C.; Sigler, C.; Mawst, L. J.; Botez, D.; Zutter, B.; Buelow, P.; Schulte, K.; Kuech, T.; Earles, T.

    2015-03-01

    On-chip resonant leaky-wave coupling of quantum cascade lasers (QCLs) emitting at 8.36 μm has been realized by selective regrowth of interelement layers in curved trenches, defined by dry and wet etching. The fabricated structure provides large index steps (Δn = 0.10) between antiguided-array element and interelement regions. In-phase-mode operation to 5.5 W front-facet emitted power in a near-diffraction-limited far-field beam pattern, with 4.5 W in the main lobe, is demonstrated. A refined fabrication process has been developed to produce phased-locked antiguided arrays of QCLs with planar geometry. The main fabrication steps in this process include non-selective regrowth of Fe:InP in interelement trenches, defined by inductive-coupled plasma (ICP) etching, a chemical polishing (CP) step to planarize the surface, non-selective regrowth of interelement layers, ICP selective etching of interelement layers, and non-selective regrowth of InP cladding layer followed by another CP step to form the element regions. This new process results in planar InGaAs/InP interelement regions, which allows for significantly improved control over the array geometry and the dimensions of element and interelement regions. Such a planar process is highly desirable to realize shorter emitting wavelength (4.6 μm) arrays, where fabrication tolerance for single-mode operation are tighter compared to 8 μm-emitting devices.

  3. Array processing for RFID tag localization exploiting multi-frequency signals

    NASA Astrophysics Data System (ADS)

    Zhang, Yimin; Li, Xin; Amin, Moeness G.

    2009-05-01

    RFID is an increasingly valuable business and technology tool for electronically identifying, locating, and tracking products, assets, and personnel. As a result, precise positioning and tracking of RFID tags and readers have received considerable attention from both academic and industrial communities. Finding the position of RFID tags is considered an important task in various real-time locating systems (RTLS). As such, numerous RFID localization products have been developed for various applications. The majority of RFID positioning systems is based on the fusion of pieces of relevant information, such as the range and the direction-of-arrival (DOA). For example, trilateration can determine the tag position by using the range information of the tag estimated from three or more spatially separated reader antennas. Triangulation is another method to locate RFID tags that use the direction-of-arrival (DOA) information estimated at multiple spatially separated locations. The RFID tag positions can also be determined through hybrid techniques that combine the range and DOA information. The focus of this paper to study the design and performance of the localization of passive RFID tags using array processing techniques in a multipath environment, and exploiting multi-frequency CW signals. The latter are used to decorrelate the coherent multipath signals for effective DOA estimation and for the purpose of accurate range estimation. Accordingly, the spatial and frequency dimensionalities are fully utilized for robust and accurate positioning of RFID tags.

  4. Near real-time, on-the-move multisensor integration and computing framework

    NASA Astrophysics Data System (ADS)

    Burnette, Chris; Schneider, Matt; Agarwal, Sanjeev; Deterline, Diane; Geyer, Chris; Phan, Chung D.; Lydic, Richard M.; Green, Kevin; Swett, Bruce

    2015-05-01

    Implanted mines and improvised devices are a persistent threat to Warfighters. Current Army countermine missions for route clearance need on-the-move standoff detection to improve the rate of advance. Vehicle-based forward looking sensors such as electro-optical and infrared (EO/IR) devices can be used to identify potential threats in near real-time (NRT) at safe standoff distance to support route clearance missions. The MOVERS (Micro-Cloud for Operational, Vehicle-Based EO-IR Reconnaissance System) is a vehicle-based multi-sensor integration and exploitation system that ingests and processes video and imagery data captured from forward-looking EO/IR and thermal sensors, and also generates target/feature alerts, using the Video Processing and Exploitation Framework (VPEF) "plug and play" video processing toolset. The MOVERS Framework provides an extensible, flexible, and scalable computing and multi-sensor integration GOTS framework that enables the capability to add more vehicles, sensors, processors or displays, and a service architecture that provides low-latency raw video and metadata streams as well as a command and control interface. Functionality in the framework is exposed through the MOVERS SDK which decouples the implementation of the service and client from the specific communication protocols.

  5. Sub-band processing for grating lobe disambiguation in sparse arrays

    NASA Astrophysics Data System (ADS)

    Hersey, Ryan K.; Culpepper, Edwin

    2014-06-01

    Combined synthetic aperture radar (SAR) and ground moving target indication (GMTI) radar modes simultaneously generate SAR and GMTI products from the same radar data. This hybrid mode provides the benefit of combined imaging and moving target displays as well as improved target recognition. However, the differing system, antenna, and waveform requirements between SAR and GMTI modes make implementing the hybrid mode challenging. The Air Force Research Laboratory (AFRL) Gotcha radar has collected wide-bandwidth, multi-channel data that can be used for both SAR and GMTI applications. The spatial channels on the Gotcha array are sparsely separated, which causes spatial grating lobes during the digital beamforming process. Grating lobes have little impact on SAR, which typically uses a single spatial channel. However, grating lobes have a large impact on GMTI, where spatial channels are used to mitigate clutter and estimate the target angle of arrival (AOA). The AOA ambiguity has a significant impact in the Gotcha data, where detections from the sidelobes and skirts of the mainlobe wrap back into the main scene causing a significant number of false alarms. This paper presents a sub-banding method to disambiguate grating lobes in the GMTI processing. This method divides the wideband SAR data into multiple frequency sub-bands. Since each sub-band has a different center frequency, the grating lobes for each sub-band appear at different angles. The method uses this variation to disambiguate target returns and places them at the correct angle of arrival (AOA). Results are presented using AFRL Gotcha radar data.

  6. A Novel Self-aligned and Maskless Process for Formation of Highly Uniform Arrays of Nanoholes and Nanopillars

    PubMed Central

    2008-01-01

    Fabrication of a large area of periodic structures with deep sub-wavelength features is required in many applications such as solar cells, photonic crystals, and artificial kidneys. We present a low-cost and high-throughput process for realization of 2D arrays of deep sub-wavelength features using a self-assembled monolayer of hexagonally close packed (HCP) silica and polystyrene microspheres. This method utilizes the microspheres as super-lenses to fabricate nanohole and pillar arrays over large areas on conventional positive and negative photoresist, and with a high aspect ratio. The period and diameter of the holes and pillars formed with this technique can be controlled precisely and independently. We demonstrate that the method can produce HCP arrays of hole of sub-250 nm size using a conventional photolithography system with a broadband UV source centered at 400 nm. We also present our 3D FDTD modeling, which shows a good agreement with the experimental results.

  7. Enhanced research in ground-penetrating radar and multisensor fusion with application to the detection and visualization of buried waste. Final report

    SciTech Connect

    Devney, A.J.; DiMarzio, C.; Kokar, M.; Miller, E.L.; Rappaport, C.M.; Weedon, W.H.

    1996-05-14

    Recognizing the difficulty and importance of the landfill remediation problems faced by DOE, and the fact that no one sensor alone can provide complete environmental site characterization, a multidisciplinary team approach was chosen for this project. The authors have developed a multisensor fusion approach that is suitable for the wide variety of sensors available to DOE, that allows separate detection algorithms to be developed and custom-tailored to each sensor. This approach is currently being applied to the Geonics EM-61 and Coleman step-frequency radar data. High-resolution array processing techniques were developed for detecting and localizing buried waste containers. A soil characterization laboratory facility was developed using a HP-8510 network analyzer and near-field coaxial probe. Both internal and external calibration procedures were developed for de-embedding the frequency-dependent soil electrical parameters from the measurements. Dispersive soil propagation modeling algorithms were also developed for simulating wave propagation in dispersive soil media. A study was performed on the application of infrared sensors to the landfill remediation problem, particularly for providing information on volatile organic compounds (VOC`s) in the atmosphere. A dust-emission lidar system is proposed for landfill remediation monitoring. Design specifications are outlined for a system which could be used to monitor dust emissions in a landfill remediation effort. The detailed results of the investigations are contained herein.

  8. The multisensor PHD filter: II. Erroneous solution via Poisson magic

    NASA Astrophysics Data System (ADS)

    Mahler, Ronald

    2009-05-01

    The theoretical foundation for the probability hypothesis density (PHD) filter is the FISST multitarget differential and integral calculus. The "core" PHD filter presumes a single sensor. Theoretically rigorous formulas for the multisensor PHD filter can be derived using the FISST calculus, but are computationally intractable. A less theoretically desirable solution-the iterated-corrector approximation-must be used instead. Recently, it has been argued that an "elementary" methodology, the "Poisson-intensity approach," renders FISST obsolete. It has further been claimed that the iterated-corrector approximation is suspect, and in its place an allegedly superior "general multisensor intensity filter" has been proposed. In this and a companion paper I demonstrate that it is these claims which are erroneous. The companion paper introduces formulas for the actual "general multisensor intensity filter." In this paper I demonstrate that (1) the "general multisensor intensity filter" fails in important special cases; (2) it will perform badly in even the easiest multitarget tracking problems; and (3) these rather serious missteps suggest that the "Poisson-intensity approach" is inherently faulty.

  9. Approaches to the Processing of Data from Large Aperture Acoustic Vertical Line Arrays

    DTIC Science & Technology

    1990-04-01

    50 3.4 GSM eigenrays across the very large vertical line array .............. 51 3.5 Conventional beam form er output...54 3.10 GSM eigenrays across the large vertical line array .................. 55 3.11 Conventional beam form er...GSM eigenrays at 162 km and at the sound axis .................... 80 4.8 ATLAS transmission loss versus range at 20 m depth ................ 81 4.9

  10. Urban structure analysis of mega city Mexico City using multisensoral remote sensing data

    NASA Astrophysics Data System (ADS)

    Taubenböck, H.; Esch, T.; Wurm, M.; Thiel, M.; Ullmann, T.; Roth, A.; Schmidt, M.; Mehl, H.; Dech, S.

    2008-10-01

    Mega city Mexico City is ranked the third largest urban agglomeration to date around the globe. The large extension as well as dynamic urban transformation and sprawl processes lead to a lack of up-to-date and area-wide data and information to measure, monitor, and understand the urban situation. This paper focuses on the capabilities of multisensoral remotely sensed data to provide a broad range of products derived from one scientific field - remote sensing - to support urban managing and planning. Therefore optical data sets from the Landsat and Quickbird sensors as well as radar data from the Shuttle Radar Topography Mission (SRTM) and the TerraSAR-X sensor are utilised. Using the multi-sensoral data sets the analysis are scale-dependent. On the one hand change detection on city level utilising the derived urban footprints enables to monitor and to assess spatiotemporal urban transformation, areal dimension of urban sprawl, its direction, and the built-up density distribution over time. On the other hand, structural characteristics of an urban landscape - the alignment and types of buildings, streets and open spaces - provide insight in the very detailed physical pattern of urban morphology on higher scale. The results show high accuracies of the derived multi-scale products. The multi-scale analysis allows quantifying urban processes and thus leading to an assessment and interpretation of urban trends.

  11. Introducing Multisensor Satellite Radiance-Based Evaluation for Regional Earth System Modeling

    NASA Technical Reports Server (NTRS)

    Matsui, T.; Santanello, J.; Shi, J. J.; Tao, W.-K.; Wu, D.; Peters-Lidard, C.; Kemp, E.; Chin, M.; Starr, D.; Sekiguchi, M.; hide

    2014-01-01

    Earth System modeling has become more complex, and its evaluation using satellite data has also become more difficult due to model and data diversity. Therefore, the fundamental methodology of using satellite direct measurements with instrumental simulators should be addressed especially for modeling community members lacking a solid background of radiative transfer and scattering theory. This manuscript introduces principles of multisatellite, multisensor radiance-based evaluation methods for a fully coupled regional Earth System model: NASA-Unified Weather Research and Forecasting (NU-WRF) model. We use a NU-WRF case study simulation over West Africa as an example of evaluating aerosol-cloud-precipitation-land processes with various satellite observations. NU-WRF-simulated geophysical parameters are converted to the satellite-observable raw radiance and backscatter under nearly consistent physics assumptions via the multisensor satellite simulator, the Goddard Satellite Data Simulator Unit. We present varied examples of simple yet robust methods that characterize forecast errors and model physics biases through the spatial and statistical interpretation of various satellite raw signals: infrared brightness temperature (Tb) for surface skin temperature and cloud top temperature, microwave Tb for precipitation ice and surface flooding, and radar and lidar backscatter for aerosol-cloud profiling simultaneously. Because raw satellite signals integrate many sources of geophysical information, we demonstrate user-defined thresholds and a simple statistical process to facilitate evaluations, including the infrared-microwave-based cloud types and lidar/radar-based profile classifications.

  12. Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

    SciTech Connect

    Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

    2007-01-30

    primarily the result of spurious identification and incorrect association of phases, and of excessive variability in estimates for the velocity and direction of incoming seismic phases. The mitigation of these causes has led to the development of two complimentary techniques for classifying seismic sources by testing detected signals under mutually exclusive event hypotheses. Both of these techniques require appropriate calibration data from the region to be monitored, and are therefore ideally suited to mining areas or other sites with recurring seismicity. The first such technique is a classification and location algorithm where a template is designed for each site being monitored which defines which phases should be observed, and at which times, for all available regional array stations. For each phase, the variability of measurements (primarily the azimuth and apparent velocity) from previous events is examined and it is determined which processing parameters (array configuration, data window length, frequency band) provide the most stable results. This allows us to define optimal diagnostic tests for subsequent occurrences of the phase in question. The calibration of templates for this project revealed significant results with major implications for seismic processing in both automatic and analyst reviewed contexts: • one or more fixed frequency bands should be chosen for each phase tested for. • the frequency band providing the most stable parameter estimates varies from site to site and a frequency band which provides optimal measurements for one site may give substantially worse measurements for a nearby site. • slowness corrections applied depend strongly on the frequency band chosen. • the frequency band providing the most stable estimates is often neither the band providing the greatest SNR nor the band providing the best array gain. For this reason, the automatic template location estimates provided here are frequently far better than those obtained by

  13. Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing

    SciTech Connect

    Harben, P E; Harris, D; Myers, S; Larsen, S; Wagoner, J; Trebes, J; Nelson, K

    2003-09-15

    Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization and in full 3D finite difference modeling as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project benefits the U.S. military and intelligence community in support of LLNL's national-security mission. FY03 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and analysis. The E3D code was enhanced to include topographic effects. Codes were developed to implement the Karhunen-Loeve (K-L) statistical methodology for generating geological heterogeneity that can be utilized in E3D modeling. The matched field processing methodology applied to vehicle tracking and based on a field calibration to characterize geological heterogeneity was tested and successfully demonstrated in a tank tracking experiment at the Nevada Test Site. A 3-seismic-array vehicle tracking testbed was installed on-site at LLNL for testing real-time seismic

  14. The Digital Signal Processing Platform for the Low Frequency Aperture Array: Preliminary Results on the Data Acquisition Unit

    NASA Astrophysics Data System (ADS)

    Naldi, Giovanni; Mattana, Andrea; Pastore, Sandro; Alderighi, Monica; Zarb Adami, Kristian; Schillirò, Francesco; Aminaei, Amin; Baker, Jeremy; Belli, Carolina; Comoretto, Gianni; Chiarucci, Simone; Chiello, Riccardo; D’Angelo, Sergio; Dalle Mura, Gabriele; De Marco, Andrea; Halsall, Rob; Magro, Alessio; Monari, Jader; Roberts, Matt; Perini, Federico; Poloni, Marco; Pupillo, Giuseppe; Rusticelli, Simone; Schiaffino, Marco; Zaccaro, Emanuele

    A signal processing hardware platform has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA). The processing board, called an Analog Digital Unit (ADU), is able to acquire and digitize broadband (up to 500MHz bandwidth) radio-frequency streams from 16 dual polarized antennas, channel the data streams and then combine them flexibly as part of a larger beamforming system. It is envisaged that there will be more than 8000 of these signal processing platforms in the first phase of the SKA, so particular attention has been devoted to ensure the design is low-cost and low-power. This paper describes the main features of the data acquisition unit of such a platform and presents preliminary results characterizing its performance.

  15. An Improved Multi-Sensor Fusion Navigation Algorithm Based on the Factor Graph.

    PubMed

    Zeng, Qinghua; Chen, Weina; Liu, Jianye; Wang, Huizhe

    2017-03-21

    An integrated navigation system coupled with additional sensors can be used in the Micro Unmanned Aerial Vehicle (MUAV) applications because the multi-sensor information is redundant and complementary, which can markedly improve the system accuracy. How to deal with the information gathered from different sensors efficiently is an important problem. The fact that different sensors provide measurements asynchronously may complicate the processing of these measurements. In addition, the output signals of some sensors appear to have a non-linear character. In order to incorporate these measurements and calculate a navigation solution in real time, the multi-sensor fusion algorithm based on factor graph is proposed. The global optimum solution is factorized according to the chain structure of the factor graph, which allows for a more general form of the conditional probability density. It can convert the fusion matter into connecting factors defined by these measurements to the graph without considering the relationship between the sensor update frequency and the fusion period. An experimental MUAV system has been built and some experiments have been performed to prove the effectiveness of the proposed method.

  16. Using GPU-generated virtual video stream for multi-sensor system

    NASA Astrophysics Data System (ADS)

    Liao, Dezhi; Hennessey, Brian

    2006-05-01

    Security and intelligence services are increasingly turning toward multi-sensor video surveillance which requires human ability to successfully fuse and comprehend the information provided by videos. A training system using the same front end as real multi-sensor system for users can significantly increase such human ability. The training system always needs scenarios replicating stressful situations which are videotaped in advance and played later. This not only puts a limitation on the training scenarios but also brings a high cost. This paper introduces a new framework, virtual video capture device for such training system. Using the latest graphics processing units (GPUs) technology, multiple video streams composed of computer graphics (CG) are generated on one high-end PC and ublished to a video stream server. Thus users can be trained using both real video streams and virtual video streams on one system. It also enables the training system to use real video streams incorporating augmented reality to improve situation awareness of the human.

  17. RheoStim: Development of an Adaptive Multi-Sensor to Prevent Venous Stasis

    PubMed Central

    Weyer, Sören; Weishaupt, Fabio; Kleeberg, Christian; Leonhardt, Steffen; Teichmann, Daniel

    2016-01-01

    Chronic venous insufficiency of the lower limbs is often underestimated and, in the absence of therapy, results in increasingly severe complications, including therapy-resistant tissue defects. Therefore, early diagnosis and adequate therapy is of particular importance. External counter pulsation (ECP) therapy is a method used to assist the venous system. The main principle of ECP is to squeeze the inner leg vessels by muscle contractions, which are evoked by functional electrical stimulation. A new adaptive trigger method is proposed, which improves and supplements the current therapeutic options by means of pulse synchronous electro-stimulation of the muscle pump. For this purpose, blood flow is determined by multi-sensor plethysmography. The hardware design and signal processing of this novel multi-sensor plethysmography device are introduced. The merged signal is used to determine the phase of the cardiac cycle, to ensure stimulation of the muscle pump during the filling phase of the heart. The pulse detection of the system is validated against a gold standard and provides a sensitivity of 98% and a false-negative rate of 2% after physical exertion. Furthermore, flow enhancement of the system has been validated by duplex ultrasonography. The results show a highly increased blood flow in the popliteal vein at the knee. PMID:27023544

  18. Mechanically flexible wireless multisensor platform for human physical activity and vitals monitoring.

    PubMed

    Chuo, Y; Marzencki, M; Hung, B; Jaggernauth, C; Tavakolian, K; Lin, P; Kaminska, B

    2010-10-01

    Practical usability of the majority of current wearable body sensor systems for multiple parameter physiological signal acquisition is limited by the multiple physical connections between sensors and the data-acquisition modules. In order to improve the user comfort and enable the use of these types of systems on active mobile subjects, we propose a wireless body sensor system that incorporates multiple sensors on a single node. This multisensor node includes signal acquisition, processing, and wireless data transmission fitted on multiple layers of a thin flexible substrate with a very small footprint. Considerations for design include size, form factor, reliable body attachment, good signal coupling, low power consumption, and user convenience. The prototype device measures 55 15 mm and is 3 mm thick. The unit is attached to the patient's chest, and is capable of performing simultaneous measurements of parameters, such as body motion, activity intensity, tilt, respiration, cardiac vibration, cardiac potential (ECG), heart rate, and body surface temperature. In this paper, we discuss the architecture of this system, including the multisensor hardware, the firmware, a mobile-phone receiver unit, and assembly of the first proof-of-concept prototype. Preliminary performance results on key elements of the system, such as power consumption, wireless range, algorithm efficiency, ECG signal quality for heart-rate calculations, as well as synchronous ECG and body activity signals are also presented.

  19. A Weighted Belief Entropy-Based Uncertainty Measure for Multi-Sensor Data Fusion.

    PubMed

    Tang, Yongchuan; Zhou, Deyun; Xu, Shuai; He, Zichang

    2017-04-22

    In real applications, how to measure the uncertain degree of sensor reports before applying sensor data fusion is a big challenge. In this paper, in the frame of Dempster-Shafer evidence theory, a weighted belief entropy based on Deng entropy is proposed to quantify the uncertainty of uncertain information. The weight of the proposed belief entropy is based on the relative scale of a proposition with regard to the frame of discernment (FOD). Compared with some other uncertainty measures in Dempster-Shafer framework, the new measure focuses on the uncertain information represented by not only the mass function, but also the scale of the FOD, which means less information loss in information processing. After that, a new multi-sensor data fusion approach based on the weighted belief entropy is proposed. The rationality and superiority of the new multi-sensor data fusion method is verified according to an experiment on artificial data and an application on fault diagnosis of a motor rotor.

  20. RheoStim: Development of an Adaptive Multi-Sensor to Prevent Venous Stasis.

    PubMed

    Weyer, Sören; Weishaupt, Fabio; Kleeberg, Christian; Leonhardt, Steffen; Teichmann, Daniel

    2016-03-24

    Chronic venous insufficiency of the lower limbs is often underestimated and, in the absence of therapy, results in increasingly severe complications, including therapy-resistant tissue defects. Therefore, early diagnosis and adequate therapy is of particular importance. External counter pulsation (ECP) therapy is a method used to assist the venous system. The main principle of ECP is to squeeze the inner leg vessels by muscle contractions, which are evoked by functional electrical stimulation. A new adaptive trigger method is proposed, which improves and supplements the current therapeutic options by means of pulse synchronous electro-stimulation of the muscle pump. For this purpose, blood flow is determined by multi-sensor plethysmography. The hardware design and signal processing of this novel multi-sensor plethysmography device are introduced. The merged signal is used to determine the phase of the cardiac cycle, to ensure stimulation of the muscle pump during the filling phase of the heart. The pulse detection of the system is validated against a gold standard and provides a sensitivity of 98% and a false-negative rate of 2% after physical exertion. Furthermore, flow enhancement of the system has been validated by duplex ultrasonography. The results show a highly increased blood flow in the popliteal vein at the knee.

  1. An Improved Multi-Sensor Fusion Navigation Algorithm Based on the Factor Graph

    PubMed Central

    Zeng, Qinghua; Chen, Weina; Liu, Jianye; Wang, Huizhe

    2017-01-01

    An integrated navigation system coupled with additional sensors can be used in the Micro Unmanned Aerial Vehicle (MUAV) applications because the multi-sensor information is redundant and complementary, which can markedly improve the system accuracy. How to deal with the information gathered from different sensors efficiently is an important problem. The fact that different sensors provide measurements asynchronously may complicate the processing of these measurements. In addition, the output signals of some sensors appear to have a non-linear character. In order to incorporate these measurements and calculate a navigation solution in real time, the multi-sensor fusion algorithm based on factor graph is proposed. The global optimum solution is factorized according to the chain structure of the factor graph, which allows for a more general form of the conditional probability density. It can convert the fusion matter into connecting factors defined by these measurements to the graph without considering the relationship between the sensor update frequency and the fusion period. An experimental MUAV system has been built and some experiments have been performed to prove the effectiveness of the proposed method. PMID:28335570

  2. Application of bistable optical logic gate arrays to all-optical digital parallel processing

    NASA Astrophysics Data System (ADS)

    Walker, A. C.

    1986-05-01

    Arrays of bistable optical gates can form the basis of an all-optical digital parallel processor. Two classes of signal input geometry exist - on- and off-axis - and lead to distinctly different device characteristics. The optical implementation of multisignal fan-in to an array of intrinsically bistable optical gates using the more efficient off-axis option is discussed together with the construction of programmable read/write memories from optically bistable devices. Finally the design of a demonstration all-optical parallel processor incorporating these concepts is presented.

  3. The dynamic research and position estimation of the towed array during the U-turn process

    NASA Astrophysics Data System (ADS)

    Yang, J. X.; Shuai, C. G.; He, L.; Zhang, S. K.; Zhou, S. T.

    2016-09-01

    A dynamic model for estimating position of ship towed array during U-turn manoeuvre is introduced and developed. Based on this model, the influences of the parameters such as time step and segment length on the numerical simulation are analysed. The results indicate that decreasing the time step has little effect on the simulation accuracy but will increase the computational time. The selection of segment length has a great influence on the estimation of ship towed array position during U-turn manoeuvre. Reducing the segment length somewhat increases the computational complexity and significantly improves simulation precision.

  4. A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a Particle Filter for Vehicle Reversing Safety.

    PubMed

    Zhang, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang

    2016-06-09

    Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a particle filter, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman filter is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a particle filter and low-rank representation is used to track the main obstacles. The low-rank representation is used to optimize an objective particle template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety.

  5. A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a Particle Filter for Vehicle Reversing Safety

    PubMed Central

    Zhang, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang

    2016-01-01

    Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a particle filter, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman filter is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a particle filter and low-rank representation is used to track the main obstacles. The low-rank representation is used to optimize an objective particle template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. PMID:27294931

  6. Optimization of Cyclostationary Signal Processing Algorithms Using Multiple Field Programmable Gate Arrays on the SRC-6 Reconfigurable Computer

    DTIC Science & Technology

    2009-09-01

    of the architecture is seen in Figure 36. Two major components make up the FPGA . The input/output blocks (IOBs) provide the interface between...programming language to make a complete program. To take advantage of FPGAs precise circuit design should be utilized by employing Verilog or VHDL. 47...runtime to approach real-time processing. The focus of the implementation is to utilize dual field programmable gate arrays ( FPGAs ) within a single

  7. The Effects of Visual Degradation on Attended Objects and the Ability to Process Unattended Objects within the Visual Array

    DTIC Science & Technology

    2010-09-01

    objects, while other times attention may be devoted to a particular object, or even just a component within a particular object. This reflects the...appear distracting and can, at times , result in capturing attention . This suggests that visual processing occurs throughout the visual array, but it...events in the environment when they correspond to where their attention is focused (Wickens & Hollands, 2000). It appears that at any given time

  8. Design and characterization of a p+/n-well SPAD array in 150nm CMOS process.

    PubMed

    Xu, Hesong; Pancheri, Lucio; Betta, Gian-Franco Dalla; Stoppa, David

    2017-05-29

    This paper reports on characterization results of a single-photon avalanche diode (SPAD) array in standard CMOS 150nm technology. The array is composed by 25 (5 × 5) SPADs, based on p(+)/n-well active junction along with a retrograde deep n-well guard ring. The square-shaped SPAD has a 10µm active diameter and 15.6µm pitch size, achieving a 39.9% array fill factor. Characterization results show a good breakdown voltage uniformity (40mV max-min) within each chip and 17mV/°C temperature coefficient. The median DCR is 0.4Hz/µm(2), and the afterpulsing probability is 0.85% for a dead time of 150ns at 3V excess bias voltage. The peak PDP is 31% at 450nm wavelength and a good uniformity (1.1% standard deviation) is observed for the array at 5V excess bias. The single SPADs exhibit a timing jitter of 52ps (FWHM) and 42ps (FWHM) under a 468-nm and a 831-nm laser, respectively. The crosstalk probability as a function of pixel-to-pixel distance and excess bias voltage is presented, and random telegraph signal (RTS) noise is also discussed in detail.

  9. High-resolution focal plane array IR detection modules and digital signal processing technologies at AIM

    NASA Astrophysics Data System (ADS)

    Cabanski, Wolfgang A.; Breiter, Rainer; Koch, R.; Mauk, Karl-Heinz; Rode, Werner; Ziegler, Johann; Eberhardt, Kurt; Oelmaier, Reinhard; Schneider, Harald; Walther, Martin

    2000-07-01

    Full video format focal plane array (FPA) modules with up to 640 X 512 pixels have been developed for high resolution imaging applications in either mercury cadmium telluride (MCT) mid wave (MWIR) infrared (IR) or platinum silicide (PtSi) and quantum well infrared photodetector (QWIP) technology as low cost alternatives to MCT for high performance IR imaging in the MWIR or long wave spectral band (LWIR). For the QWIP's, a new photovoltaic technology was introduced for improved NETD performance and higher dynamic range. MCT units provide fast frame rates > 100 Hz together with state of the art thermal resolution NETD < 20 mK for short snapshot integration times of typically 2 ms. PtSi and QWIP modules are usually operated in a rolling frame integration mode with frame rates of 30 - 60 Hz and provide thermal resolutions of NETD < 80 mK for PtSi and NETD < 20 mK for QWIP, respectively. Due to the lower quantum efficiency compared to MCT, however, the integration time is typically chosen to be as long 10 - 20 ms. The heat load of the integrated detector cooler assemblies (IDCAs) could be reduced to an amount as low, that a 1 W split liner cooler provides sufficient cooling power to operate the modules -- including the QWIP with 60 K operation temperature -- at ambient temperatures up to 65 degrees Celsius. Miniaturized command/control electronics (CCE) available for all modules provide a standardized digital interface, with 14 bit analogue to digital conversion for state to the art correctability, access to highly dynamic scenes without any loss of information and simplified exchangeability of the units. New modular image processing hardware platforms and software for image visualization and nonuniformity correction including scene based self learning algorithms had to be developed to accomplish for the high data rates of up to 18 M pixels/s with 14-bit deep data, allowing to take into account nonlinear effects to access the full NETD by accurate reduction of residual

  10. Multisensor monitoring of sea surface state of the coastal zone

    NASA Astrophysics Data System (ADS)

    Lavrova, Olga; Mityagina, Marina; Bocharova, Tatina

    Results of many-year monitoring of the state of coastal zone based on a multisensor approach are presented. The monitoring is aimed at solving the following tasks: operational mapping of parameters characterizing the state and pollution (coastal, ship and biogenic) of water; analysis of meteorological state and its effect on the drift and spread of pollutants; study of coastal circulation patterns and their impact on the drift and spread of pollutants; deriving typical pollution distribution patterns in the coastal zone.Processing and analysis is performed using data in visual, infrared and microwave ranges from ERS-2 SAR, Envisat ASAR/MERIS, Terra and Aqua MODIS and NOAA AVHRR instruments. These are complimented with ground data from meteorological stations on the shore and results of satellite data processing of previous periods. The main regions of interest are the Russian sectors of the Black and Azov Seas, southeastern part of the Baltic Sea, and northern and central regions of the Caspian Sea. Adjacent coasts are extremely populated and have well-developed industry, agriculture and rapidly growing tourist sectors. The necessity of constant monitoring of the sea state there is obvious.The monitoring activities allow us to accumulate extensive material for the study of hydrodynamic processes in the regions, in particular water circulation. Detailing the occurrence, evolution and drift of smalland meso-scale vortex structures is crucial for the knowledge of the mechanisms determining mixing and circulation processes in the coastal zone. These mechanisms play an important role in ecological, hydrodynamic and meteorological status of a coastal zone. Special attention is paid to the sea surface state in the Kerch Strait, where a tanker catastrophe took place on November 11, 2007 causing a spillage of over 1.5 thousand tons of heavy oil. The Kerch Strait is characterized by a complex current system with current directions changing to their opposites depending on

  11. A dense spot size converter array fabricated in a generic process on InP

    NASA Astrophysics Data System (ADS)

    D'Agostino, D.; Kleijn, E.; Santos, R.; Ambrosius, H. P. M. M.; Smit, M. K.

    2013-05-01

    Integrated spot size converters (SSCs) are key components for efficient coupling between Photonic Integrated Circuits (PICs) and fibre-arrays. We report a compact SSC which is suitable for integration into dense arrays with a pitch down to 25 μm and compatible with our generic InP-based platform technology, which supports integration of SOAs and Electro Optical Modulators with a range of passive components. The small pitch supports coupling tens of on-chip optical waveguide ports to fiber arrays via a low-loss dielectric interposer chip. The density allows the design of a customized optical bus between the InP PIC and the interposer chip. The dielectric chip may simply expand to the pitch of a fiber array but also contain low-loss passive circuitry like delay-lines, high Q-filters and multiplexers. The latter enables the formation of a hybrid integration platform with our InP-based technology. Efficient coupling is obtained by adiabatically transforming the sub-micron modes of the InP waveguides to the 3 μm diameter mode of the interposer. We tested our SSCs by coupling to a lensed fibre with a mode field diameter of 2.5 μm. Coupling losses were found to be as low as 0.6 dB per fiber chip coupling for device lengths of a few 100 μm. We also measured the crosstalk from one input port to output ports adjacent to the targeted output port. We present simple design rules for reducing the crosstalk to neighbouring output ports below -50 dB. The quality and uniformity of the SSCs is demonstrated by fabrication of an 8 x 8 AWG demultiplexer between two SSC arrays placed at input and output ports. We measured an insertion loss between fibres of 4 dB for the central channel of the AWG, which is record low for an InP-based device.

  12. Dynamic templating: a large area processing route for the assembly of periodic arrays of sub-micrometer and nanoscale structures

    NASA Astrophysics Data System (ADS)

    Farzinpour, Pouyan; Sundar, Aarthi; Gilroy, Kyle D.; Eskin, Zachary E.; Hughes, Robert A.; Neretina, Svetlana

    2013-02-01

    A substrate-based templated assembly route has been devised which offers large-area, high-throughput capabilities for the fabrication of periodic arrays of sub-micrometer and nanometer-scale structures. The approach overcomes a significant technological barrier to the widespread use of substrate-based templated assembly by eliminating the need for periodic templates having nanoscale features. Instead, it relies upon the use of a dynamic template with dimensions that evolve in time from easily fabricated micrometer dimensions to those on the nanoscale as the assembly process proceeds. The dynamic template consists of a pedestal of a sacrificial material, typically antimony, upon which an ultrathin layer of a second material is deposited. When heated, antimony sublimation results in a continuous reduction in template size where the motion of the sublimation fronts direct the diffusion of atoms of the second material to a predetermined location. The route has broad applicability, having already produced periodic arrays of gold, silver, copper, platinum, nickel, cobalt, germanium and Au-Ag alloys on substrates as diverse as silicon, sapphire, silicon-carbide, graphene and glass. Requiring only modest levels of instrumentation, the process provides an enabling route for any reasonably equipped researcher to fabricate periodic arrays that would otherwise require advanced fabrication facilities.A substrate-based templated assembly route has been devised which offers large-area, high-throughput capabilities for the fabrication of periodic arrays of sub-micrometer and nanometer-scale structures. The approach overcomes a significant technological barrier to the widespread use of substrate-based templated assembly by eliminating the need for periodic templates having nanoscale features. Instead, it relies upon the use of a dynamic template with dimensions that evolve in time from easily fabricated micrometer dimensions to those on the nanoscale as the assembly process

  13. Multisensor 3D tracking for counter small unmanned air vehicles (CSUAV)

    NASA Astrophysics Data System (ADS)

    Vasquez, Juan R.; Tarplee, Kyle M.; Case, Ellen E.; Zelnio, Anne M.; Rigling, Brian D.

    2008-04-01

    A variety of unmanned air vehicles (UAVs) have been developed for both military and civilian use. The typical large UAV is typically state owned, whereas small UAVs (SUAVs) may be in the form of remote controlled aircraft that are widely available. The potential threat of these SUAVs to both the military and civilian populace has led to research efforts to counter these assets via track, ID, and attack. Difficulties arise from the small size and low radar cross section when attempting to detect and track these targets with a single sensor such as radar or video cameras. In addition, clutter objects make accurate ID difficult without very high resolution data, leading to the use of an acoustic array to support this function. This paper presents a multi-sensor architecture that exploits sensor modes including EO/IR cameras, an acoustic array, and future inclusion of a radar. A sensor resource management concept is presented along with preliminary results from three of the sensors.

  14. Overseas testing of a multisensor landmine detection system: results and lessons learned

    NASA Astrophysics Data System (ADS)

    Keranen, Joe G.; Topolosky, Zeke

    2009-05-01

    The Nemesis detection system has been developed to provide an efficient and reliable unmanned, multi-sensor, groundbased platform to detect and mark landmines. The detection system consists of two detection sensor arrays: a Ground Penetrating Synthetic Aperture Radar (GPSAR) developed by Planning Systems, Inc. (PSI) and an electromagnetic induction (EMI) sensor array developed by Minelab Electronics, PTY. Limited. Under direction of the Night Vision and Electronic Sensors Directorate (NVESD), overseas testing was performed at Kampong Chhnang Test Center (KCTC), Cambodia, from May 12-30, 2008. Test objectives included: evaluation of detection performance, demonstration of real-time visualization and alarm generation, and evaluation of system operational efficiency. Testing was performed on five sensor test lanes, each consisting of a unique soil mixture and three off-road lanes which include curves, overgrowth, potholes, and non-uniform lane geometry. In this paper, we outline the test objectives, procedures, results, and lessons learned from overseas testing. We also describe the current state of the system, and plans for future enhancements and modifications including clutter rejection and feature-level fusion.

  15. Seismo-Acoustic Array Observations of Shallow Conduit Processes at Fuego Volcano, Guatemala

    NASA Astrophysics Data System (ADS)

    Waite, G. P.; Lyons, J. J.; Nadeau, P. A.

    2008-12-01

    We deployed small antennas of six broadband seismic and five acoustic sensors 900 m north of the active vent of Fuego volcano during January 2008 to investigate the source of explosions and background tremor. The L-shaped seismic array had stations spaced 30 m apart with one axis parallel to the ridge that runs north from the summit and the other axis down to the west for a total aperture of 150 m. The infrasound sensors were deployed in a similar array, but with an average station spacing of 50 m. There was no lava effusion during the four-day deployment, but explosions were clearly recorded with the seismic and acoustic arrays approximately once per hour with varied amounts of ash, and with durations from ~20-150 s. In addition to the explosions, our seismic array recorded constant volcanic tremor at 1.9 Hz and various discrete events that were not generally detected by the acoustic array. The dominant class of such events, which repeated approximately 10 times per hour, had an impulsive onset with first motion toward the vent, a short duration of <5 s, dominant frequencies from 1-3 Hz, and no infrasound component. All of the seismic signals were predominately surface waves radiating from the direction of the vent. Apparent velocities from overlapping 1 or 2 s windows of explosions decreased from 1-2 km/s at the onset to about 500 m/s at the arrival of the ground-coupled airwave. Events with no apparent infrasound also have low apparent velocities of 0.5 - 2 km/s, suggesting they are occurring at shallow depths. For these events, a weak P-wave arrival was typically observed about 200 ms before the shear- and surface-wave train. We also recorded some explosions that had very little seismic signal until the arrival of the ground-coupled airwave. Source inversion was not possible due to the limited array geometry, but we used forward modeling of candidate source geometries to infer differences between the sources of the dominant seismic signals. Constraints from

  16. Advanced Signaling Strategies for the Hybrid MIMO Phased-Array Radar

    DTIC Science & Technology

    2010-05-01

    Multiple - Input Multiple Output , or MIMO , radar systems are next-generation radar systems with... Multiple - Input Multiple Output ( MIMO ) radar. A HMPAR comprises a large number MP, of T/R elements, organized into M subarrays of P elements each. Within...multisensor radar architecture that combines elements of traditional phased-array radar with the emerging technology of Multiple - Input Multiple Out-

  17. Multi-sensor radiotelemetry system for intestinal motility measurement.

    PubMed

    Biao, H; Guozheng, Y; Peng, Z

    2009-01-01

    In order to measure the important physiological parameters such as temperature, pressure and pH value, we developed a miniature, high precision, non-invasive and multi-sensor radiotelemetry system. The system comprises multi-sensor radiotelemetry capsule, data logger, location device and workstation. The radiotelemetry capsule can monitor the pH, pressure and temperature of the entire intestinal tract and send the data to the data logger outside the body through a wireless communication link. After the capsule is egested from the anus, further analysis of the physiological parameter data saved in the data logger can be performed via the special software installed at the workstation. Clinical experiments prove that the radiotelemetry system is non-invasive and reliable. Moreover it is found that the radiotelemetry system is an effective method to study intestine motility characteristics.

  18. Effective World Modeling: Multisensor Data Fusion Methodology for Automated Driving

    PubMed Central

    Elfring, Jos; Appeldoorn, Rein; van den Dries, Sjoerd; Kwakkernaat, Maurice

    2016-01-01

    The number of perception sensors on automated vehicles increases due to the increasing number of advanced driver assistance system functions and their increasing complexity. Furthermore, fail-safe systems require redundancy, thereby increasing the number of sensors even further. A one-size-fits-all multisensor data fusion architecture is not realistic due to the enormous diversity in vehicles, sensors and applications. As an alternative, this work presents a methodology that can be used to effectively come up with an implementation to build a consistent model of a vehicle’s surroundings. The methodology is accompanied by a software architecture. This combination minimizes the effort required to update the multisensor data fusion system whenever sensors or applications are added or replaced. A series of real-world experiments involving different sensors and algorithms demonstrates the methodology and the software architecture. PMID:27727171

  19. Multi-Sensor Registration of Earth Remotely Sensed Imagery

    NASA Technical Reports Server (NTRS)

    LeMoigne, Jacqueline; Cole-Rhodes, Arlene; Eastman, Roger; Johnson, Kisha; Morisette, Jeffrey; Netanyahu, Nathan S.; Stone, Harold S.; Zavorin, Ilya; Zukor, Dorothy (Technical Monitor)

    2001-01-01

    Assuming that approximate registration is given within a few pixels by a systematic correction system, we develop automatic image registration methods for multi-sensor data with the goal of achieving sub-pixel accuracy. Automatic image registration is usually defined by three steps; feature extraction, feature matching, and data resampling or fusion. Our previous work focused on image correlation methods based on the use of different features. In this paper, we study different feature matching techniques and present five algorithms where the features are either original gray levels or wavelet-like features, and the feature matching is based on gradient descent optimization, statistical robust matching, and mutual information. These algorithms are tested and compared on several multi-sensor datasets covering one of the EOS Core Sites, the Konza Prairie in Kansas, from four different sensors: IKONOS (4m), Landsat-7/ETM+ (30m), MODIS (500m), and SeaWIFS (1000m).

  20. Geocoding and stereo display of tropical forest multisensor datasets

    NASA Technical Reports Server (NTRS)

    Welch, R.; Jordan, T. R.; Luvall, J. C.

    1990-01-01

    Concern about the future of tropical forests has led to a demand for geocoded multisensor databases that can be used to assess forest structure, deforestation, thermal response, evapotranspiration, and other parameters linked to climate change. In response to studies being conducted at the Braulino Carrillo National Park, Costa Rica, digital satellite and aircraft images recorded by Landsat TM, SPOT HRV, Thermal Infrared Multispectral Scanner, and Calibrated Airborne Multispectral Scanner sensors were placed in register using the Landsat TM image as the reference map. Despite problems caused by relief, multitemporal datasets, and geometric distortions in the aircraft images, registration was accomplished to within + or - 20 m (+ or - 1 data pixel). A digital elevation model constructed from a multisensor Landsat TM/SPOT stereopair proved useful for generating perspective views of the rugged, forested terrain.

  1. Advances in Multi-Sensor Data Fusion: Algorithms and Applications

    PubMed Central

    Dong, Jiang; Zhuang, Dafang; Huang, Yaohuan; Fu, Jingying

    2009-01-01

    With the development of satellite and remote sensing techniques, more and more image data from airborne/satellite sensors have become available. Multi-sensor image fusion seeks to combine information from different images to obtain more inferences than can be derived from a single sensor. In image-based application fields, image fusion has emerged as a promising research area since the end of the last century. The paper presents an overview of recent advances in multi-sensor satellite image fusion. Firstly, the most popular existing fusion algorithms are introduced, with emphasis on their recent improvements. Advances in main applications fields in remote sensing, including object identification, classification, change detection and maneuvering targets tracking, are described. Both advantages and limitations of those applications are then discussed. Recommendations are addressed, including: (1) Improvements of fusion algorithms; (2) Development of “algorithm fusion” methods; (3) Establishment of an automatic quality assessment scheme. PMID:22408479

  2. Design of surveillance and multisensor anti-aerial systems

    NASA Astrophysics Data System (ADS)

    Nahum, C.; Cantalloube, H.

    1995-01-01

    Software ROSACE (Optimization of Realistic Systems, Contributes to the Design and the Evaluation), is developed within the framework of the study methodology of multisensors for anti-aircraft defense and is financed by the DRET (contract n 91-34-846). This document concerns a interactive tool, that is evolutionary, portable and of assistance to the definition, the qualification, and the optimization of multisensor systems for anti-aircraft monitoring and defense. This product constitutes a support for the expertise and search for new treatments which utilize the fusion of information and are likely to improve the performance of the system. These algorithms primarily ensure (but not exclusively) the tasks of detection and continuation or classification of air machines and make it possible to analyze the reliability of the system confronted with different scenarios.

  3. Geocoding and stereo display of tropical forest multisensor datasets

    NASA Technical Reports Server (NTRS)

    Welch, R.; Jordan, T. R.; Luvall, J. C.

    1990-01-01

    Concern about the future of tropical forests has led to a demand for geocoded multisensor databases that can be used to assess forest structure, deforestation, thermal response, evapotranspiration, and other parameters linked to climate change. In response to studies being conducted at the Braulino Carrillo National Park, Costa Rica, digital satellite and aircraft images recorded by Landsat TM, SPOT HRV, Thermal Infrared Multispectral Scanner, and Calibrated Airborne Multispectral Scanner sensors were placed in register using the Landsat TM image as the reference map. Despite problems caused by relief, multitemporal datasets, and geometric distortions in the aircraft images, registration was accomplished to within + or - 20 m (+ or - 1 data pixel). A digital elevation model constructed from a multisensor Landsat TM/SPOT stereopair proved useful for generating perspective views of the rugged, forested terrain.

  4. Fabrication process for CMUT arrays with polysilicon electrodes, nanometre precision cavity gaps and through-silicon vias

    NASA Astrophysics Data System (ADS)

    Due-Hansen, J.; Midtbø, K.; Poppe, E.; Summanwar, A.; Jensen, G. U.; Breivik, L.; Wang, D. T.; Schjølberg-Henriksen, K.

    2012-07-01

    Capacitive micromachined ultrasound transducers (CMUTs) can be used to realize miniature ultrasound probes. Through-silicon vias (TSVs) allow for close integration of the CMUT and read-out electronics. A fabrication process enabling the realization of a CMUT array with TSVs is being developed. The integrated process requires the formation of highly doped polysilicon electrodes with low surface roughness. A process for polysilicon film deposition, doping, CMP, RIE and thermal annealing that resulted in a film with sheet resistance of 4.0 Ω/□ and a surface roughness of 1 nm rms has been developed. The surface roughness of the polysilicon film was found to increase with higher phosphorus concentrations. The surface roughness also increased when oxygen was present in the thermal annealing ambient. The RIE process for etching CMUT cavities in the doped polysilicon gave a mean etch depth of 59.2 ± 3.9 nm and a uniformity across the wafer ranging from 1.0 to 4.7%. The two presented processes are key processes that enable the fabrication of CMUT arrays suitable for applications in for instance intravascular cardiology and gastrointestinal imaging.

  5. Effects of photon enhanced lifetime and form anisotropy in silicon nanowire arrays on efficiency of nonlinear-optical processes

    NASA Astrophysics Data System (ADS)

    Golovan, L. A.; Zabotnov, S. V.; Tkachenko, N. B.; Neskoromnaya, A. V.; Presnov, D. E.; Efimova, A. I.; Osminkina, L. A.; Timoshenko, V. Yu.; Petrov, G. I.; Yakovlev, V. V.

    2017-09-01

    Arrays of silicon nanowires (SiNWs) of about 100 nm in diameter formed by metal-assisted chemical etching of crystalline silicon (c-Si) substrates were studied regarding efficiency of optical interactions in them. Strong scattering in the SiNW arrays results in enhanced photon lifetime in them, which was evidenced by measurement of the cross-correlation function for femtosecond pulses scattered by the SiNW arrays. This effect results in an order of magnitude growth of efficiency such processes as spontaneous Raman scattering and third-harmonic (TH) generation compared to the signals for c-Si. Using (110) oriented c-Si substrate we managed to make well-oriented tilted SiNWs demonstrating strongly anisotropy of the TH and coherent anti-Stokes Raman scattering signals. In particular, efficiencies of these processes differ significantly when incident radiation propagates along or perpendicular to the SINWs. The obtained results could be explained by variations of the local fields in SiNWs and scattering cross-section.

  6. Conversion of electromagnetic energy in Z-pinch process of single planar wire arrays at 1.5 MA

    SciTech Connect

    Liangping, Wang; Mo, Li; Juanjuan, Han; Ning, Guo; Jian, Wu; Aici, Qiu

    2014-06-15

    The electromagnetic energy conversion in the Z-pinch process of single planar wire arrays was studied on Qiangguang generator (1.5 MA, 100 ns). Electrical diagnostics were established to monitor the voltage of the cathode-anode gap and the load current for calculating the electromagnetic energy. Lumped-element circuit model of wire arrays was employed to analyze the electromagnetic energy conversion. Inductance as well as resistance of a wire array during the Z-pinch process was also investigated. Experimental data indicate that the electromagnetic energy is mainly converted to magnetic energy and kinetic energy and ohmic heating energy can be neglected before the final stagnation. The kinetic energy can be responsible for the x-ray radiation before the peak power. After the stagnation, the electromagnetic energy coupled by the load continues increasing and the resistance of the load achieves its maximum of 0.6–1.0 Ω in about 10–20 ns.

  7. Dimension-Controllable Microtube Arrays by Dynamic Holographic Processing as 3D Yeast Culture Scaffolds for Asymmetrical Growth Regulation.

    PubMed

    Ji, Shengyun; Yang, Liang; Hu, Yanlei; Ni, Jincheng; Du, Wenqiang; Li, Jiawen; Zhao, Gang; Wu, Dong; Chu, Jiaru

    2017-09-01

    Transparent microtubes can function as unique cell culture scaffolds, because the tubular 3D microenvironment they provide is very similar to the narrow space of capillaries in vivo. However, how to realize the fabrication of microtube-arrays with variable cross-section dynamically remains challenging. Here, a dynamic holographic processing method for producing high aspect ratio (≈20) microtubes with tunable outside diameter (6-16 µm) and inside diameter (1-10 µm) as yeast culture scaffolds is reported. A ring-structure Bessel beam is modulated from a typical Gaussian-distributed femtosecond laser beam by a spatial light modulator. By combining the axial scanning of the focused beam and the dynamic display of holograms, dimension-controllable microtube arrays (straight, conical, and drum-shape) are rapidly produced by two-photon polymerization. The outside and inside diameters, tube heights, and spatial arrangements are readily tuned by loading different computer-generated holograms and changing the processing parameters. The transparent microtube array as a nontrivial tool for capturing and culturing the budding yeasts reveals the significant effect of tube diameter on budding characteristics. In particular, the conical tube with the inside diameter varying from 5 to 10 µm has remarkable asymmetrical regulation on the growth trend of captured yeasts. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. AGV trace sensing and processing technology based on RGB color sensor array

    NASA Astrophysics Data System (ADS)

    Xu, Kebao; Zhu, Ping; Wang, Juncheng; Yun, Yuliang

    2009-05-01

    AGV(Automatic Guided Vehicle) is widely used in manufacturing factories, harbors, docks and logistics fields, because of its accurate automatic tracking. An AGV tracking method of detecting trace color based on RGB color sensor is provided here. DR, DG, DB values of trace color are obtained by color sensor, with which hue value denoting trace color characteristic can be calculated. Combined with graph theory algorithm, hue value can be used as a parameter for tracking deviation and branch identification to implement shortest path tracking. In addition, considering discreteness and uncertainty of single sensor in detecting trace information, sensor array is adopted for information fusion to achieve accurate tracking. Compared to tracking trace by single intensity sensor, AGV tracking based on RGB color sensor array has much better trace tracking and branch identification performances on complex roads.

  9. Simultaneous processing of photographic and accelerator array data from sled impact experiment

    NASA Astrophysics Data System (ADS)

    Ash, M. E.

    1982-12-01

    A Quaternion-Kalman filter model is derived to simultaneously analyze accelerometer array and photographic data from sled impact experiments. Formulas are given for the quaternion representation of rotations, the propagation of dynamical states and their partial derivatives, the observables and their partial derivatives, and the Kalman filter update of the state given the observables. The observables are accelerometer and tachometer velocity data of the sled relative to the track, linear accelerometer array and photographic data of the subject relative to the sled, and ideal angular accelerometer data. The quaternion constraints enter through perfect constraint observations and normalization after a state update. Lateral and fore-aft impact tests are analyzed with FORTRAN IV software written using the formulas of this report.

  10. Multi-Sensor Improved Sea Surface Temperature (MISST) for GODAE

    DTIC Science & Technology

    2007-01-01

    provided with state-of-the- art SST data products and analyses. OBJECTIVES To produce multi-sensor improved SSTs and successfully assess the impact...difference in extra-tropical forecast performance for NOGAPS was found. NRL globally evaluated the existing operational MODAS AVHRR-only SST and...blends IR and MW SSTs with in situ observations. The NCODA SST will replace the existing MODAS SST which utilizes only IR AVHRR observations from

  11. Multi-sensor Improved Sea Surface Temperature (MISST) for GODAE

    DTIC Science & Technology

    2007-09-30

    state-of-the- art SST data products and analyses. OBJECTIVES To produce multi-sensor improved SSTs and successfully assess the impact of these...tropical forecast performance for NOGAPS was found. NRL globally evaluated the existing operational MODAS AVHRR-only SST and RSS MW SST...with in situ observations. The NCODA SST will replace the existing MODAS SST which utilizes only IR AVHRR observations from polar orbiters. To

  12. Multi-Sensor Improved Sea Surface Temperature (MISST) for GODAE

    DTIC Science & Technology

    2008-01-01

    activities and are provided with state-of-the- art SST data products and analyses. OBJECTIVES To produce multi-sensor improved SSTs and successfully...sea level pressure. (SLP) B) The track forecast errors. NRL globally evaluated the existing operational MODAS AVHRR-only SST and RSS MW SST...the development of the NCODA SST, which blends IR and MW SSTs with in situ observations. The NCODA SST will replace the existing MODAS SST which

  13. Computer Program Description - A Long Period Array Processing Package for ILLIAC IV

    DTIC Science & Technology

    1974-10-11

    thought of as a series of 16-bit bytes. It is the function of DEMI to retrieve the data bytes from the input file and organize...records. Each record consists of a series of 16-bit bytes. While the Length and exact format of each record depends upon the array at ^hich...or in the CU scratch pad memory. The format of the input is accommodated by manipulating the pointer to space over gaps. In a series of nested

  14. Capillary-Induced Self-Organization of Soft Pillar Arrays into Moir'e Patterns by Dynamic Feedback Process

    NASA Astrophysics Data System (ADS)

    Kang, Sung; Wu, Ning; Grinthal, Alison; Aizenberg, Joanna

    2012-02-01

    We report a self-organized pattern formation of polymer nanopillar arrays by dynamic feedback: two nanopillar arrays collectively structure a sandwiched liquid and pattern the menisci, which bend the pillars into Moir'e patterns as it evaporates. Like the conventional Moir'e phenomenon, the patterns are deterministic and tunable by mismatch angle, yet additional behaviors---chirality from achiral starting motifs and preservation of the patterns after the surfaces are separated---appear from the feedback process. Patterning menisci based on this mechanism provides a simple, scalable approach for making a series of complex, long-range-ordered structures. Reference: Sung H. Kang, Ning Wu, Alison Grinthal, and Joanna Aizenberg, Phys. Rev. Lett., 107, 177802 (2011).

  15. A miniature electronic nose system based on an MWNT-polymer microsensor array and a low-power signal-processing chip.

    PubMed

    Chiu, Shih-Wen; Wu, Hsiang-Chiu; Chou, Ting-I; Chen, Hsin; Tang, Kea-Tiong

    2014-06-01

    This article introduces a power-efficient, miniature electronic nose (e-nose) system. The e-nose system primarily comprises two self-developed chips, a multiple-walled carbon nanotube (MWNT)-polymer based microsensor array, and a low-power signal-processing chip. The microsensor array was fabricated on a silicon wafer by using standard photolithography technology. The microsensor array comprised eight interdigitated electrodes surrounded by SU-8 "walls," which restrained the material-solvent liquid in a defined area of 650 × 760 μm(2). To achieve a reliable sensor-manufacturing process, we used a two-layer deposition method, coating the MWNTs and polymer film as the first and second layers, respectively. The low-power signal-processing chip included array data acquisition circuits and a signal-processing core. The MWNT-polymer microsensor array can directly connect with array data acquisition circuits, which comprise sensor interface circuitry and an analog-to-digital converter; the signal-processing core consists of memory and a microprocessor. The core executes the program, classifying the odor data received from the array data acquisition circuits. The low-power signal-processing chip was designed and fabricated using the Taiwan Semiconductor Manufacturing Company 0.18-μm 1P6M standard complementary metal oxide semiconductor process. The chip consumes only 1.05 mW of power at supply voltages of 1 and 1.8 V for the array data acquisition circuits and the signal-processing core, respectively. The miniature e-nose system, which used a microsensor array, a low-power signal-processing chip, and an embedded k-nearest-neighbor-based pattern recognition algorithm, was developed as a prototype that successfully recognized the complex odors of tincture, sorghum wine, sake, whisky, and vodka.

  16. Solution-Processed Large-Area Nanocrystal Arrays of Metal-Organic Frameworks as Wearable, Ultrasensitive, Electronic Skin for Health Monitoring.

    PubMed

    Fu, Xiaolong; Dong, Huanli; Zhen, Yonggang; Hu, Wenping

    2015-07-15

    Pressure sensors based on solution-processed metal-organic frameworks nanowire arrays are fabricated with very low cost, flexibility, high sensitivity, and ease of integration into sensor arrays. Furthermore, the pressure sensors are suitable for monitoring and diagnosing biomedical signals such as radial artery pressure waveforms in real time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Large Enhancement of Field Emission from ZnO Nanocone Arrays via Patterning Process

    NASA Astrophysics Data System (ADS)

    Le Shim, Ee; Bae, Joonho; Yoo, Eunji; Kang, Chijung; Choi, Young Jin

    2010-11-01

    We report on the direct observation of enhanced field emissions from patterned ZnO nanocones compared with the plain geometry of ZnO nanocones. For the unambiguous comparison of field emissions from patterned nanocones and plain(nonpatterned) nanocones, periodic arrays of ZnO nanowires were fabricated on Si by photolithography, RCA-1(aq) solution etching, and the hydrothermal growth method. The conelike morphology formation was achieved by anisotropic etching on the different crystal planes of ZnO nanowires in an aqueous solution of acetic acid [CH3COOH(aq)]. As the control sample of plane ZnO nanocones, the ZnO nanowires with a plain geometry were synthesized under the same conditions as the patterned sample. The field emission measurements on the plain ZnO nanocones and patterned ZnO nanocones reveal that the turn-on field decreases from 6.0 V/µm (plane nanocone arrays) to 3.8 V/µm (patterned nanocone arrays).

  18. Large Enhancement of Field Emission from ZnO Nanocone Arrays via Patterning Process

    NASA Astrophysics Data System (ADS)

    Shim, Ee Le; Bae, Joonho; Yoo, Eunji; Kang, Chijung; Choi, Young Jin

    2010-11-01

    We report on the direct observation of enhanced field emissions from patterned ZnO nanocones compared with the plain geometry of ZnO nanocones. For the unambiguous comparison of field emissions from patterned nanocones and plain(nonpatterned) nanocones, periodic arrays of ZnO nanowires were fabricated on Si by photolithography, RCA-1(aq) solution etching, and the hydrothermal growth method. The conelike morphology formation was achieved by anisotropic etching on the different crystal planes of ZnO nanowires in an aqueous solution of acetic acid [CH3COOH(aq)]. As the control sample of plane ZnO nanocones, the ZnO nanowires with a plain geometry were synthesized under the same conditions as the patterned sample. The field emission measurements on the plain ZnO nanocones and patterned ZnO nanocones reveal that the turn-on field decreases from 6.0 V/μm (plane nanocone arrays) to 3.8 V/μm (patterned nanocone arrays).

  19. Maximum-likelihood methods for array processing based on time-frequency distributions

    NASA Astrophysics Data System (ADS)

    Zhang, Yimin; Mu, Weifeng; Amin, Moeness G.

    1999-11-01

    This paper proposes a novel time-frequency maximum likelihood (t-f ML) method for direction-of-arrival (DOA) estimation for non- stationary signals, and compares this method with conventional maximum likelihood DOA estimation techniques. Time-frequency distributions localize the signal power in the time-frequency domain, and as such enhance the effective SNR, leading to improved DOA estimation. The localization of signals with different t-f signatures permits the division of the time-frequency domain into smaller regions, each contains fewer signals than those incident on the array. The reduction of the number of signals within different time-frequency regions not only reduces the required number of sensors, but also decreases the computational load in multi- dimensional optimizations. Compared to the recently proposed time- frequency MUSIC (t-f MUSIC), the proposed t-f ML method can be applied in coherent environments, without the need to perform any type of preprocessing that is subject to both array geometry and array aperture.

  20. Array tomography: imaging stained arrays.

    PubMed

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time-consuming and require some practice to perfect. In this protocol, tissue arrays are imaged using conventional wide-field fluorescence microscopy. Images can be captured manually or, with the appropriate software and hardware, the process can be automated.

  1. Development of a multi-sensor CMOS ASIC

    NASA Astrophysics Data System (ADS)

    van der Merwe, D. G.

    2016-02-01

    A multi-sensor application specific integrated circuit has been developed with a number of sensors: capacitive, inductive, magnetic, ambient light, infrared and acceleration. The capacitive sensing is implemented using a unique, patented, charge transfer technique allowing the measurement of very small capacitances while at the same time eliminating the effects of unwanted parasitic capacitances in the measurement circuit. For cost effective implementation the charge transfer measurement circuit has been has been modified, augmented and expanded to not only measure capacitance but also to act as the measurement circuit for all the sensors. Enabling the multi-sensor chip to measure acceleration on a range of MEMs accelerometer chips including a single axis accelerometer, a dual axis xy accelerometer and a z-axis accelerometer, innovative and patent pending techniques have been developed and implemented on standard CMOS. The CMOS ASIC and a MEMs chip will be double bonded in a plastic package offering multi-sensor capability in a small low cost package.

  2. Design of a multisensor data fusion system for target detection

    NASA Astrophysics Data System (ADS)

    Thomopoulos, Stelios C.; Okello, Nickens N.; Kadar, Ivan; Lovas, Louis A.

    1993-09-01

    The objective of this paper is to discuss the issues that are involved in the design of a multisensor fusion system and provide a systematic analysis and synthesis methodology for the design of the fusion system. The system under consideration consists of multifrequency (similar) radar sensors. However, the fusion design must be flexible to accommodate additional dissimilar sensors such as IR, EO, ESM, and Ladar. The motivation for the system design is the proof of the fusion concept for enhancing the detectability of small targets in clutter. In the context of down-selecting the proper configuration for multisensor (similar and dissimilar, and centralized vs. distributed) data fusion, the issues of data modeling, fusion approaches, and fusion architectures need to be addressed for the particular application being considered. Although the study of different approaches may proceed in parallel, the interplay among them is crucial in selecting a fusion configuration for a given application. The natural sequence for addressing the three different issues is to begin from the data modeling, in order to determine the information content of the data. This information will dictate the appropriate fusion approach. This, in turn, will lead to a global fusion architecture. Both distributed and centralized fusion architectures are used to illustrate the design issues along with Monte-Carlo simulation performance comparison of a single sensor versus a multisensor centrally fused system.

  3. Sparse Downscaling and Adaptive Fusion of Multi-sensor Precipitation

    NASA Astrophysics Data System (ADS)

    Ebtehaj, M.; Foufoula, E.

    2011-12-01

    The past decades have witnessed a remarkable emergence of new sources of multiscale multi-sensor precipitation data including data from global spaceborne active and passive sensors, regional ground based weather surveillance radars and local rain-gauges. Resolution enhancement of remotely sensed rainfall and optimal integration of multi-sensor data promise a posteriori estimates of precipitation fluxes with increased accuracy and resolution to be used in hydro-meteorological applications. In this context, new frameworks are proposed for resolution enhancement and multiscale multi-sensor precipitation data fusion, which capitalize on two main observations: (1) sparseness of remotely sensed precipitation fields in appropriately chosen transformed domains, (e.g., in wavelet space) which promotes the use of the newly emerged theory of sparse representation and compressive sensing for resolution enhancement; (2) a conditionally Gaussian Scale Mixture (GSM) parameterization in the wavelet domain which allows exploiting the efficient linear estimation methodologies, while capturing the non-Gaussian data structure of rainfall. The proposed methodologies are demonstrated using a data set of coincidental observations of precipitation reflectivity images by the spaceborne precipitation radar (PR) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite and ground-based NEXRAD weather surveillance Doppler radars. Uniqueness and stability of the solution, capturing non-Gaussian singular structure of rainfall, reduced uncertainty of estimation and efficiency of computation are the main advantages of the proposed methodologies over the commonly used standard Gaussian techniques.

  4. Multi-Sensor Data Fusion for Future Telematics Application

    NASA Astrophysics Data System (ADS)

    Kim, Seong-Baek; Lee, Seung-Yong; Choi, Ji-Hoon; Choi, Kyung-Ho; Jang, Byung-Tae

    2003-12-01

    In this paper, we present multi-sensor data fusion for telematics application. Successful telematics can be realized through the integration of navigation and spatial information. The well-determined acquisition of vehicle's position plays a vital role in application service. The development of GPS is used to provide the navigation data, but the performance is limited in areas where poor satellite visibility environment exists. Hence, multi-sensor fusion including IMU (Inertial Measurement Unit), GPS (Global Positioning System), and DMI (Distance Measurement Indicator) is required to provide the vehicle's position to service provider and driver behind the wheel. The multi-sensor fusion is implemented via algorithm based on Kalman Filtering technique. Navigation accuracy can be enhanced using this filtering approach. For the verification of fusion approach, land vehicle test was performed and the results were discussed. Results showed that the horizontal position errors were suppressed around 1 meter level accuracy under simulated Non-GPS availability environment. Under normal GPS environment, the horizontal position errors were under 40 cm in curve trajectory and 27cm in linear trajectory, which are definitely depending on vehicular dynamics.

  5. Oil exploration oriented multi-sensor image fusion algorithm

    NASA Astrophysics Data System (ADS)

    Xiaobing, Zhang; Wei, Zhou; Mengfei, Song

    2017-04-01

    In order to accurately forecast the fracture and fracture dominance direction in oil exploration, in this paper, we propose a novel multi-sensor image fusion algorithm. The main innovations of this paper lie in that we introduce Dual-tree complex wavelet transform (DTCWT) in data fusion and divide an image to several regions before image fusion. DTCWT refers to a new type of wavelet transform, and it is designed to solve the problem of signal decomposition and reconstruction based on two parallel transforms of real wavelet. We utilize DTCWT to segment the features of the input images and generate a region map, and then exploit normalized Shannon entropy of a region to design the priority function. To test the effectiveness of our proposed multi-sensor image fusion algorithm, four standard pairs of images are used to construct the dataset. Experimental results demonstrate that the proposed algorithm can achieve high accuracy in multi-sensor image fusion, especially for images of oil exploration.

  6. A multi-sensor scenario for coastal surveillance

    NASA Astrophysics Data System (ADS)

    van den Broek, A. C.; van den Broek, S. P.; van den Heuvel, J. C.; Schwering, P. B. W.; van Heijningen, A. W. P.

    2007-10-01

    Maritime borders and coastal zones are susceptible to threats such as drug trafficking, piracy, undermining economical activities. At TNO Defence, Security and Safety various studies aim at improving situational awareness in a coastal zone. In this study we focus on multi-sensor surveillance of the coastal environment. We present a study on improving classification results for small sea surface targets using an advanced sensor suite and a scenario in which a small boat is approaching the coast. A next generation sensor suite mounted on a tower has been defined consisting of a maritime surveillance and tracking radar system, capable of producing range profiles and ISAR imagery of ships, an advanced infrared camera and a laser range profiler. For this suite we have developed a multi-sensor classification procedure, which is used to evaluate the capabilities for recognizing and identifying non-cooperative ships in coastal waters. We have found that the different sensors give complementary information. Each sensor has its own specific distance range in which it contributes most. A multi-sensor approach reduces the number of misclassifications and reliable classification results are obtained earlier compared to a single sensor approach.

  7. Multi-sensor Mapping of Volcanic Plumes and Clouds

    NASA Astrophysics Data System (ADS)

    Realmuto, V. J.

    2006-12-01

    The instruments aboard the NASA series of Earth Observing System satellites provide a rich suite of measurements for the mapping of volcanic plumes and clouds. In this presentation we focus on analyses of data acquired with the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Atmospheric Infrared Sounder (AIRS), Moderate-Resolution Imaging Spectrometer (MODIS), and Multiangle Imaging SpectroRadiometer (MISR). ASTER, MODIS, AIRS, and MISR provide complimentary information on the quantity and distribution of sulfur dioxide, silicate ash, and sulfate aerosols within plumes. In addition, MISR data are used to derive estimates of cloud-top altitude, wind direction, and wind speed. The key to multi-sensor mapping is the availability of a standard set of tools for the processing of data from different instruments. To date we have used the MAP_SO2 toolkit to analyze the thermal infrared (TIR) data from MODIS, ASTER, and AIRS. MAP_SO2, a graphic user interface to the MODTRAN radiative transfer model, provides tools for the estimation of emissivity spectra, water vapor and ozone correction factors, surface temperature, and concentrations of SO2. We use the MISR_Shift toolkit to estimate plume-top altitudes and local wind vectors. Our continuous refinement of MAP_SO2 has resulted in lower detection limits for SO2 and lower sensitivity to the presence of sulfate aerosols and ash. Our plans for future refinements of MAP_SO2 include the incorporation of AIRS-based profiles of atmospheric temperature, water vapor and ozone, and MISR-based maps of plume-top altitude into the plume mapping procedures. The centerpiece of our study is a time-series of data acquired during the 2002-2003 and 2006 eruptions of Mount Etna. Time-series measurements are the only means of recording dynamic phenomena and characterizing the processes that generate such phenomena. We have also analyzed data acquired over Klychevskoy, Bezymianny, and Sheveluch (Kamchatka), Augustine

  8. A parallel implementation of a multisensor feature-based range-estimation method

    NASA Technical Reports Server (NTRS)

    Suorsa, Raymond E.; Sridhar, Banavar

    1993-01-01

    There are many proposed vision based methods to perform obstacle detection and avoidance for autonomous or semi-autonomous vehicles. All methods, however, will require very high processing rates to achieve real time performance. A system capable of supporting autonomous helicopter navigation will need to extract obstacle information from imagery at rates varying from ten frames per second to thirty or more frames per second depending on the vehicle speed. Such a system will need to sustain billions of operations per second. To reach such high processing rates using current technology, a parallel implementation of the obstacle detection/ranging method is required. This paper describes an efficient and flexible parallel implementation of a multisensor feature-based range-estimation algorithm, targeted for helicopter flight, realized on both a distributed-memory and shared-memory parallel computer.

  9. A Spatiotemporal Indexing Approach for Efficient Processing of Big Array-Based Climate Data with MapReduce

    NASA Technical Reports Server (NTRS)

    Li, Zhenlong; Hu, Fei; Schnase, John L.; Duffy, Daniel Q.; Lee, Tsengdar; Bowen, Michael K.; Yang, Chaowei

    2016-01-01

    Climate observations and model simulations are producing vast amounts of array-based spatiotemporal data. Efficient processing of these data is essential for assessing global challenges such as climate change, natural disasters, and diseases. This is challenging not only because of the large data volume, but also because of the intrinsic high-dimensional nature of geoscience data. To tackle this challenge, we propose a spatiotemporal indexing approach to efficiently manage and process big climate data with MapReduce in a highly scalable environment. Using this approach, big climate data are directly stored in a Hadoop Distributed File System in its original, native file format. A spatiotemporal index is built to bridge the logical array-based data model and the physical data layout, which enables fast data retrieval when performing spatiotemporal queries. Based on the index, a data-partitioning algorithm is applied to enable MapReduce to achieve high data locality, as well as balancing the workload. The proposed indexing approach is evaluated using the National Aeronautics and Space Administration (NASA) Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate reanalysis dataset. The experimental results show that the index can significantly accelerate querying and processing (10 speedup compared to the baseline test using the same computing cluster), while keeping the index-to-data ratio small (0.0328). The applicability of the indexing approach is demonstrated by a climate anomaly detection deployed on a NASA Hadoop cluster. This approach is also able to support efficient processing of general array-based spatiotemporal data in various geoscience domains without special configuration on a Hadoop cluster.

  10. Modular Ultrasound Array Doppler Velocimeter with FPGA-based Signal Processing for Real-time Flow Mapping in Liquid Metal

    NASA Astrophysics Data System (ADS)

    Nauber, R.; Thieme, N.; Beyer, H.; Büttner, L.; Räbiger, D.; Eckert, S.; Czarske, J.

    Investigating the complex interaction of conductive fluids and magnetic fields is relevant for a variety of applications from basic research in magnetohydrodynamics (MHD) to modeling industrial processes involving metal melts, such as the crystal growth process in the photovoltaic industry. This enables targeted optimizations of the melt flow and allows to significantly increase the yield and energy efficiency of industrial processes. However, experimental studies in this field are often limited by the performance of flow instrumentation for opaque liquids. We present an ultrasound array Doppler velocimeter (UADV) for flow mapping in opaque liquids at room temperature. It is modular and flexible regarding its measurement configuration, for instance it allows capturing two velocity components in two planes (2d - 2c). It uses up to 9 linear arrays with a total element count of 225, driven in a parallelized time division multiplex (TDM) scheme. A FPGA-based signal pre-processing allows to handle the massive data bandwidth of typ. 1.2 GB/s and enables a continuous and near-realtime operation of the measurement system. The capabilities of the UADV system are demonstrated in a basic MHD research experiment with a metal melt (GaInSn) in a cubic container of (67 mm)3. The flow induced by a rotating magnetic field is captured with a temporal resolution of 250 ms for the horizontal and vertical central cross-section of the cube.

  11. A non catalytic process for the production of nested bulk carbon nanotubes and nanotube arrays and their electrochemical behavior

    NASA Astrophysics Data System (ADS)

    Riehl, Bill L.

    To date, no one has devised a scalable process for the production of electrochemically clean carbon nanotubes. The application of carbon nanotubes has been limited by three factors: cost, consistency, and purity. Nearly all carbon nanotube processes fall under the chemical vapor deposition method. This results in inconsistencies in diameter and length, as well as residual metal contamination. Residual metal contamination is perhaps the greatest impediment of carbon nanotube use for electrochemical applications. The goal of this effort is to develop and demonstrate a process for the production of electrochemically clean carbon nanotube materials suitable for applications such as chemical/biological sensors, batteries/fuel cells, and electrochemical double layer capacitors. To ensure no metal contamination is present in the "as produced" material, a process was developed that uses the carbo-thermal decomposition of the transition metal and metalloid carbides that is applicable to CNT arrays and production of bulk CNT materials. A substrate attached carbon nanotube modified electrode is demonstrated.

  12. Real-time processing of fast-scan cyclic voltammetry (FSCV) data using a field-programmable gate array (FPGA).

    PubMed

    Bozorgzadeh, Bardia; Covey, Daniel P; Heidenreich, Byron A; Garris, Paul A; Mohseni, Pedram

    2014-01-01

    This paper reports the hardware implementation of a digital signal processing (DSP) unit for real-time processing of data obtained by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM), an electrochemical transduction technique for high-resolution monitoring of brain neurochemistry. Implemented on a field-programmable gate array (FPGA), the DSP unit comprises a decimation filter and an embedded processor to process the oversampled FSCV data and obtain in real time a temporal profile of concentration variation along with a chemical signature to identify the target neurotransmitter. Interfaced with an integrated, FSCV-sensing front-end, the DSP unit can successfully process FSCV data obtained by bolus injection of dopamine in a flow cell as well as electrically evoked, transient dopamine release in the dorsal striatum of an anesthetized rat.

  13. Performance of a process, near infrared, photo-diode array based instrument for hydrocarbon fuels analysis

    SciTech Connect

    Workman, J. Jr; McDermott, L.

    1995-12-31

    The use of a 1024 element silicon photodiode-array (PDA) detector for the design of analytical spectrophotometers has been proposed since the early 1970s. The practical implementation of this technology did not occur for another decade. Traditional problems associated with interferometer-and moving dispersive grating based systems arise from mechanical misalignment and wear of critical moving parts with time. PDA technology represents the potential of increased measurement longevity due to a fixed grating and detector assembly. The purpose of this paper is to delineate the particulars of design and performance characteristics associated with using PDA-based spectrophotometer for hydrocarbon fuels analysis.

  14. Hierarchical multisensor analysis for robotic exploration

    NASA Astrophysics Data System (ADS)

    Eberlein, Susan; Yates, Gigi; Majani, Eric

    1991-03-01

    Robotic vehicles for lunar and Mars exploration will carry an array of complex instruments requiring real-time data interpretation and fusion. The system described here uses hierarchical multiresolution analysis of visible and multispectral images to extract information on mineral composition, texture and object shape. This information is used to characterize the site geology and choose interesting samples for acquisition. Neural networks are employed for many data analysis steps. A decision tree progressively integrates information from multiple instruments and performs goal-driven decision making. The system is designed to incorporate more instruments and data types as they become available.

  15. Hierarchical multisensor analysis for robotic exploration

    NASA Technical Reports Server (NTRS)

    Eberlein, Susan; Yates, Gigi; Majani, Eric

    1991-01-01

    Robotic vehicles for lunar and Mars exploration will carry an array of complex instruments requiring real-time data interpretation and fusion. The system described here uses hierarchical multiresolution analysis of visible and multispectral images to extract information on mineral composition, texture and object shape. This information is used to characterize the site geology and choose interesting samples for acquisition. Neural networks are employed for many data analysis steps. A decision tree progressively integrates information from multiple instruments and performs goal-driven decision making. The system is designed to incorporate more instruments and data types as they become available.

  16. Light absorption processes and optimization of ZnO/CdTe core-shell nanowire arrays for nanostructured solar cells.

    PubMed

    Michallon, Jérôme; Bucci, Davide; Morand, Alain; Zanuccoli, Mauro; Consonni, Vincent; Kaminski-Cachopo, Anne

    2015-02-20

    The absorption processes of extremely thin absorber solar cells based on ZnO/CdTe core-shell nanowire (NW) arrays with square, hexagonal or triangular arrangements are investigated through systematic computations of the ideal short-circuit current density using three-dimensional rigorous coupled wave analysis. The geometrical dimensions are optimized for optically designing these solar cells: the optimal NW diameter, height and array period are of 200 ± 10 nm, 1-3 μm and 350-400 nm for the square arrangement with CdTe shell thickness of 40-60 nm. The effects of the CdTe shell thickness on the absorption of ZnO/CdTe NW arrays are revealed through the study of two optical key modes: the first one is confining the light into individual NWs, the second one is strongly interacting with the NW arrangement. It is also shown that the reflectivity of the substrate can improve Fabry-Perot resonances within the NWs: the ideal short-circuit current density is increased by 10% for the ZnO/fluorine-doped tin oxide (FTO)/ideal reflector as compared to the ZnO/FTO/glass substrate. Furthermore, the optimized square arrangement absorbs light more efficiently than both optimized hexagonal and triangular arrangements. Eventually, the enhancement factor of the ideal short-circuit current density is calculated as high as 1.72 with respect to planar layers, showing the high optical potentiality of ZnO/CdTe core-shell NW arrays.

  17. Processing of Antenna-Array Signals on the Basis of the Interference Model Including a Rank-Deficient Correlation Matrix

    NASA Astrophysics Data System (ADS)

    Rodionov, A. A.; Turchin, V. I.

    2017-06-01

    We propose a new method of signal processing in antenna arrays, which is called the Maximum-Likelihood Signal Classification. The proposed method is based on the model in which interference includes a component with a rank-deficient correlation matrix. Using numerical simulation, we show that the proposed method allows one to ensure variance of the estimated arrival angle of the plane wave, which is close to the Cramer-Rao lower boundary and more efficient than the best-known MUSIC method. It is also shown that the proposed technique can be efficiently used for estimating the time dependence of the useful signal.

  18. Phonon processes in vertically aligned silicon nanowire arrays produced by low-cost all-solution galvanic displacement method

    NASA Astrophysics Data System (ADS)

    Banerjee, Debika; Trudeau, Charles; Gerlein, Luis Felipe; Cloutier, Sylvain G.

    2016-03-01

    The nanoscale engineering of silicon can significantly change its bulk optoelectronic properties to make it more favorable for device integration. Phonon process engineering is one way to enhance inter-band transitions in silicon's indirect band structure alignment. This paper demonstrates phonon localization at the tip of silicon nanowires fabricated by galvanic displacement using wet electroless chemical etching of a bulk silicon wafer. High-resolution Raman micro-spectroscopy reveals that such arrayed structures of silicon nanowires display phonon localization behaviors, which could help their integration into the future generations of nano-engineered silicon nanowire-based devices such as photodetectors and solar cells.

  19. Free-running ADC- and FPGA-based signal processing method for brain PET using GAPD arrays

    NASA Astrophysics Data System (ADS)

    Hu, Wei; Choi, Yong; Hong, Key Jo; Kang, Jihoon; Jung, Jin Ho; Huh, Youn Suk; Lim, Hyun Keong; Kim, Sang Su; Kim, Byung-Tae; Chung, Yonghyun

    2012-02-01

    Currently, for most photomultiplier tube (PMT)-based PET systems, constant fraction discriminators (CFD) and time to digital converters (TDC) have been employed to detect gamma ray signal arrival time, whereas anger logic circuits and peak detection analog-to-digital converters (ADCs) have been implemented to acquire position and energy information of detected events. As compared to PMT the Geiger-mode avalanche photodiodes (GAPDs) have a variety of advantages, such as compactness, low bias voltage requirement and MRI compatibility. Furthermore, the individual read-out method using a GAPD array coupled 1:1 with an array scintillator can provide better image uniformity than can be achieved using PMT and anger logic circuits. Recently, a brain PET using 72 GAPD arrays (4×4 array, pixel size: 3 mm×3 mm) coupled 1:1 with LYSO scintillators (4×4 array, pixel size: 3 mm×3 mm×20 mm) has been developed for simultaneous PET/MRI imaging in our laboratory. Eighteen 64:1 position decoder circuits (PDCs) were used to reduce GAPD channel number and three off-the-shelf free-running ADC and field programmable gate array (FPGA) combined data acquisition (DAQ) cards were used for data acquisition and processing. In this study, a free-running ADC- and FPGA-based signal processing method was developed for the detection of gamma ray signal arrival time, energy and position information all together for each GAPD channel. For the method developed herein, three DAQ cards continuously acquired 18 channels of pre-amplified analog gamma ray signals and 108-bit digital addresses from 18 PDCs. In the FPGA, the digitized gamma ray pulses and digital addresses were processed to generate data packages containing pulse arrival time, baseline value, energy value and GAPD channel ID. Finally, these data packages were saved to a 128 Mbyte on-board synchronous dynamic random access memory (SDRAM) and then transferred to a host computer for coincidence sorting and image reconstruction. In order to

  20. Direct fabrication of compound-eye microlens array on curved surfaces by a facile femtosecond laser enhanced wet etching process

    NASA Astrophysics Data System (ADS)

    Bian, Hao; Wei, Yang; Yang, Qing; Chen, Feng; Zhang, Fan; Du, Guangqing; Yong, Jiale; Hou, Xun

    2016-11-01

    We report a direct fabrication of an omnidirectional negative microlens array on a curved substrate by a femtosecond laser enhanced chemical etching process, which is utilized as a molding template for duplicating bioinspired compound eyes. The femtosecond laser treatment of the curved glass substrate employs a common x-y-z stage without rotating the sample surface perpendicular to the laser beam, and uniform, omnidirectional-aligned negative microlenses are generated after a hydrofluoric acid etching. Using the negative microlens array on the concave glass substrate as a molding template, we fabricate an artificial compound eye with 3000 positive microlenses of 95-μm diameter close-packed on a 5-mm polymer hemisphere. Compared to the transferring process, the negative microlenses directly fabricated on the curved mold by our method are distortion-free, and the duplicated artificial eye presents clear and uniform imaging capabilities. This work provides a facile and efficient route to the fabrication of microlenses on any curved substrates without complicated alignment and motion control processes, which has the potential for the development of new microlens-based devices and systems.

  1. True-time-delay transmit/receive optical beam-forming system for phased arrays and other signal processing applications

    NASA Astrophysics Data System (ADS)

    Toughlian, Edward N.; Zamuda, H.; Carter, Charity A.

    1994-06-01

    This paper addresses the problem of dynamic optical processing for the control of phased array antennas. The significant result presented is the demonstration of a continuously variable photonic RF/microwave delay line. Specifically, it is shown that by applying spatial frequency dependent optical phase compensation in an optical heterodyne process, variable RF delay can be achieved over a prescribed frequency band. Experimental results which demonstrate the performance of the delay line with regard to both maximum delay and resolution over a broad bandwidth are presented. Additionally, a spatially integrated optical system is proposed for control of phased array antennas. The integrated system provides mechanical stability, essentially eliminates the drift problems associated with free space optical systems, and can provide high packing density. This approach uses a class of spatial light modulator known as a deformable mirror device and leads to a steerable arbitrary antenna radiation pattern of the true time delay type. Also considered is the ability to utilize the delay line as a general photonic signal processing element in an adaptive (reconfigurable) transversal frequency filter configuration. Such systems are widely applicable in jammer/noise canceling systems, broadband ISDN, spread spectrum secure communications and the like.

  2. Signal processing of MEMS gyroscope arrays to improve accuracy using a 1st order Markov for rate signal modeling.

    PubMed

    Jiang, Chengyu; Xue, Liang; Chang, Honglong; Yuan, Guangmin; Yuan, Weizheng

    2012-01-01

    This paper presents a signal processing technique to improve angular rate accuracy of the gyroscope by combining the outputs of an array of MEMS gyroscope. A mathematical model for the accuracy improvement was described and a Kalman filter (KF) was designed to obtain optimal rate estimates. Especially, the rate signal was modeled by a first-order Markov process instead of a random walk to improve overall performance. The accuracy of the combined rate signal and affecting factors were analyzed using a steady-state covariance. A system comprising a six-gyroscope array was developed to test the presented KF. Experimental tests proved that the presented model was effective at improving the gyroscope accuracy. The experimental results indicated that six identical gyroscopes with an ARW noise of 6.2 °/√h and a bias drift of 54.14 °/h could be combined into a rate signal with an ARW noise of 1.8 °/√h and a bias drift of 16.3 °/h, while the estimated rate signal by the random walk model has an ARW noise of 2.4 °/√h and a bias drift of 20.6 °/h. It revealed that both models could improve the angular rate accuracy and have a similar performance in static condition. In dynamic condition, the test results showed that the first-order Markov process model could reduce the dynamic errors 20% more than the random walk model.

  3. Integration of Si-CMOS embedded photo detector array and mixed signal processing system with embedded optical waveguide input

    NASA Astrophysics Data System (ADS)

    Kim, Daeik D.; Thomas, Mikkel A.; Brooke, Martin A.; Jokerst, Nan M.

    2004-06-01

    Arrays of embedded bipolar junction transistor (BJT) photo detectors (PD) and a parallel mixed-signal processing system were fabricated as a silicon complementary metal oxide semiconductor (Si-CMOS) circuit for the integration optical sensors on the surface of the chip. The circuit was fabricated with AMI 1.5um n-well CMOS process and the embedded PNP BJT PD has a pixel size of 8um by 8um. BJT PD was chosen to take advantage of its higher gain amplification of photo current than that of PiN type detectors since the target application is a low-speed and high-sensitivity sensor. The photo current generated by BJT PD is manipulated by mixed-signal processing system, which consists of parallel first order low-pass delta-sigma oversampling analog-to-digital converters (ADC). There are 8 parallel ADCs on the chip and a group of 8 BJT PDs are selected with CMOS switches. An array of PD is composed of three or six groups of PDs depending on the number of rows.

  4. A data fusion algorithm for multi-sensor microburst hazard assessment

    NASA Technical Reports Server (NTRS)

    Wanke, Craig R.; Hansman, R. John

    1994-01-01

    A recursive model-based data fusion algorithm for multi-sensor microburst hazard assessment is described. An analytical microburst model is used to approximate the actual windfield, and a set of 'best' model parameters are estimated from measured winds. The winds corresponding to the best parameter set can then be used to compute alerting factors such as microburst position, extent, and intensity. The estimation algorithm is based on an iterated extended Kalman filter which uses the microburst model parameters as state variables. Microburst state dynamic and process noise parameters are chosen based on measured microburst statistics. The estimation method is applied to data from a time-varying computational simulation of a historical microburst event to demonstrate its capabilities and limitations. Selection of filter parameters and initial conditions is discussed. Computational requirements and datalink bandwidth considerations are also addressed.

  5. Enhanced Flexibility and Reusability through State Machine-Based Architectures for Multisensor Intelligent Robotics

    PubMed Central

    Herrero, Héctor; Outón, Jose Luis; Puerto, Mildred; Sallé, Damien; López de Ipiña, Karmele

    2017-01-01

    This paper presents a state machine-based architecture, which enhances the flexibility and reusability of industrial robots, more concretely dual-arm multisensor robots. The proposed architecture, in addition to allowing absolute control of the execution, eases the programming of new applications by increasing the reusability of the developed modules. Through an easy-to-use graphical user interface, operators are able to create, modify, reuse and maintain industrial processes, increasing the flexibility of the cell. Moreover, the proposed approach is applied in a real use case in order to demonstrate its capabilities and feasibility in industrial environments. A comparative analysis is presented for evaluating the presented approach versus traditional robot programming techniques. PMID:28561750

  6. Enhanced Flexibility and Reusability through State Machine-Based Architectures for Multisensor Intelligent Robotics.

    PubMed

    Herrero, Héctor; Outón, Jose Luis; Puerto, Mildred; Sallé, Damien; López de Ipiña, Karmele

    2017-05-31

    This paper presents a state machine-based architecture, which enhances the flexibility and reusability of industrial robots, more concretely dual-arm multisensor robots. The proposed architecture, in addition to allowing absolute control of the execution, eases the programming of new applications by increasing the reusability of the developed modules. Through an easy-to-use graphical user interface, operators are able to create, modify, reuse and maintain industrial processes, increasing the flexibility of the cell. Moreover, the proposed approach is applied in a real use case in order to demonstrate its capabilities and feasibility in industrial environments. A comparative analysis is presented for evaluating the presented approach versus traditional robot programming techniques.

  7. Application of multi-sensors parallel fusion system in photoelectric tracing

    NASA Astrophysics Data System (ADS)

    Cheng, Guo-ying; Cai, Sheng; Gao, Hui-bin; Zhang, Shu-mei; Qiao, Yan-Feng

    2008-12-01

    To solve the real-time and reliability problem of tracking servo-control system in optoelectronic theodolite, a multisensors parallel processing system was proposed. Misdistances of three different wavebands were imported into system, and then prediction was done in DSP1 to get the actual position information. Data fusion was accomplished in PPGA imported by multi channel buffer serial port. The compound position information was used to control the theodolite. The results were compared with external guide data in DSP2 to implement correction of above calculation, and then were imported to epistemic machine through PXI interface. The simulation experiment of each calculation unit showed that this system could solve the real-time problem of feature level data fusion. The simulation result showed that the system can satisfy the real-time requirement with 1.25ms in theodolite with three imaging systems, while sampling frequency of photoelectric encoder was 800 Hz.

  8. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

    NASA Technical Reports Server (NTRS)

    Brewster, L.; Johnston, A.; Howard, R.; Mitchell, J.; Cryan, S.

    2007-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-loop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of"pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  9. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

    NASA Technical Reports Server (NTRS)

    Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

    2008-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  10. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

    NASA Technical Reports Server (NTRS)

    Brewster, L.; Johnston, A.; Howard, R.; Mitchell, J.; Cryan, S.

    2007-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-loop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of"pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  11. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

    NASA Technical Reports Server (NTRS)

    Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

    2008-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  12. Ambiguity Function Analysis for the Hybrid Mimo Phased-Array Radar (Postprint)

    DTIC Science & Technology

    2009-09-01

    Multiple - Input Multiple Output , or MIMO , radar systems are next-generation radar systems with multiple transmit and receive...architecture that combines elements of traditional phased-array radar with the emerging technology of Multiple - Input Multiple Out- put ( MIMO ) radar. A HMPAR...a multisensor radar architecture that combines elements of traditional phased-array radar with the emerging technology of Multiple - Input Multiple

  13. NASA 1990 Multisensor Airborne Campaigns (MACs) for ecosystem and watershed studies

    NASA Technical Reports Server (NTRS)

    Wickland, Diane E.; Asrar, Ghassem; Murphy, Robert E.

    1991-01-01

    The Multisensor Airborne Campaign (MAC) focus within NASA's former Land Processes research program was conceived to achieve the following objectives: to acquire relatively complete, multisensor data sets for well-studied field sites, to add a strong remote sensing science component to ecology-, hydrology-, and geology-oriented field projects, to create a research environment that promotes strong interactions among scientists within the program, and to more efficiently utilize and compete for the NASA fleet of remote sensing aircraft. Four new MAC's were conducted in 1990: the Oregon Transect Ecosystem Research (OTTER) project along an east-west transect through central Oregon, the Forest Ecosystem Dynamics (FED) project at the Northern Experimental Forest in Howland, Maine, the MACHYDRO project in the Mahantango Creek watershed in central Pennsylvania, and the Walnut Gulch project near Tombstone, Arizona. The OTTER project is testing a model that estimates the major fluxes of carbon, nitrogen, and water through temperate coniferous forest ecosystems. The focus in the project is on short time-scale (days-year) variations in ecosystem function. The FED project is concerned with modeling vegetation changes of forest ecosystems using remotely sensed observations to extract biophysical properties of forest canopies. The focus in this project is on long time-scale (decades to millenia) changes in ecosystem structure. The MACHYDRO project is studying the role of soil moisture and its regulating effects on hydrologic processes. The focus of the study is to delineate soil moisture differences within a basin and their changes with respect to evapotranspiration, rainfall, and streamflow. The Walnut Gulch project is focused on the effects of soil moisture in the energy and water balance of arid and semiarid ecosystems and their feedbacks to the atmosphere via thermal forcing.

  14. NASA 1990 Multisensor Airborne Campaigns (MACs) for ecosystem and watershed studies

    NASA Astrophysics Data System (ADS)

    Wickland, Diane E.; Asrar, Ghassem; Murphy, Robert E.

    The Multisensor Airborne Campaign (MAC) focus within NASA's former Land Processes research program was conceived to achieve the following objectives: to acquire relatively complete, multisensor data sets for well-studied field sites, to add a strong remote sensing science component to ecology-, hydrology-, and geology-oriented field projects, to create a research environment that promotes strong interactions among scientists within the program, and to more efficiently utilize and compete for the NASA fleet of remote sensing aircraft. Four new MAC's were conducted in 1990: the Oregon Transect Ecosystem Research (OTTER) project along an east-west transect through central Oregon, the Forest Ecosystem Dynamics (FED) project at the Northern Experimental Forest in Howland, Maine, the MACHYDRO project in the Mahantango Creek watershed in central Pennsylvania, and the Walnut Gulch project near Tombstone, Arizona. The OTTER project is testing a model that estimates the major fluxes of carbon, nitrogen, and water through temperate coniferous forest ecosystems. The focus in the project is on short time-scale (days-year) variations in ecosystem function. The FED project is concerned with modeling vegetation changes of forest ecosystems using remotely sensed observations to extract biophysical properties of forest canopies. The focus in this project is on long time-scale (decades to millenia) changes in ecosystem structure. The MACHYDRO project is studying the role of soil moisture and its regulating effects on hydrologic processes. The focus of the study is to delineate soil moisture differences within a basin and their changes with respect to evapotranspiration, rainfall, and streamflow. The Walnut Gulch project is focused on the effects of soil moisture in the energy and water balance of arid and semiarid ecosystems and their feedbacks to the atmosphere via thermal forcing.

  15. Scalable stacked array piezoelectric deformable mirror for astronomy and laser processing applications

    SciTech Connect

    Wlodarczyk, Krystian L. Maier, Robert R. J.; Hand, Duncan P.; Bryce, Emma; Hutson, David; Kirk, Katherine; Schwartz, Noah; Atkinson, David; Beard, Steven; Baillie, Tom; Parr-Burman, Phil; Strachan, Mel

    2014-02-15

    A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

  16. Primary Dendrite Array: Observations from Ground-Based and Space Station Processed Samples

    NASA Technical Reports Server (NTRS)

    Tewari, Surendra N.; Grugel, Richard N.; Erdman, Robert G.; Poirier, David R.

    2012-01-01

    Influence of natural convection on primary dendrite array morphology during directional solidification is being investigated under a collaborative European Space Agency-NASA joint research program, Microstructure Formation in Castings of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST). Two Aluminum-7 wt pct Silicon alloy samples, MICAST6 and MICAST7, were directionally solidified in microgravity on the International Space Station. Terrestrially grown dendritic monocrystal cylindrical samples were remelted and directionally solidified at 18 K per centimeter (MICAST6) and 28 K per centimeter (MICAST7). Directional solidification involved a growth speed step increase (MICAST6-from 5 to 50 millimeters per second) and a speed decrease (MICAST7-from 20 to 10 millimeters per second). Distribution and morphology of primary dendrites is currently being characterized in these samples, and also in samples solidified on earth under nominally similar thermal gradients and growth speeds. Primary dendrite spacing and trunk diameter measurements from this investigation will be presented.

  17. Primary Dendrite Array Morphology: Observations from Ground-based and Space Station Processed Samples

    NASA Technical Reports Server (NTRS)

    Tewari, Surendra; Rajamure, Ravi; Grugel, Richard; Erdmann, Robert; Poirier, David

    2012-01-01

    Influence of natural convection on primary dendrite array morphology during directional solidification is being investigated under a collaborative European Space Agency-NASA joint research program, "Microstructure Formation in Castings of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST)". Two Aluminum-7 wt pct Silicon alloy samples, MICAST6 and MICAST7, were directionally solidified in microgravity on the International Space Station. Terrestrially grown dendritic monocrystal cylindrical samples were remelted and directionally solidified at 18 K/cm (MICAST6) and 28 K/cm (MICAST7). Directional solidification involved a growth speed step increase (MICAST6-from 5 to 50 micron/s) and a speed decrease (MICAST7-from 20 to 10 micron/s). Distribution and morphology of primary dendrites is currently being characterized in these samples, and also in samples solidified on earth under nominally similar thermal gradients and growth speeds. Primary dendrite spacing and trunk diameter measurements from this investigation will be presented.

  18. Scalable stacked array piezoelectric deformable mirror for astronomy and laser processing applications.

    PubMed

    Wlodarczyk, Krystian L; Bryce, Emma; Schwartz, Noah; Strachan, Mel; Hutson, David; Maier, Robert R J; Atkinson, David; Beard, Steven; Baillie, Tom; Parr-Burman, Phil; Kirk, Katherine; Hand, Duncan P

    2014-02-01

    A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

  19. From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release

    NASA Astrophysics Data System (ADS)

    Lentati, L.; Shannon, R. M.; Coles, W. A.; Verbiest, J. P. W.; van Haasteren, R.; Ellis, J. A.; Caballero, R. N.; Manchester, R. N.; Arzoumanian, Z.; Babak, S.; Bassa, C. G.; Bhat, N. D. R.; Brem, P.; Burgay, M.; Burke-Spolaor, S.; Champion, D.; Chatterjee, S.; Cognard, I.; Cordes, J. M.; Dai, S.; Demorest, P.; Desvignes, G.; Dolch, T.; Ferdman, R. D.; Fonseca, E.; Gair, J. R.; Gonzalez, M. E.; Graikou, E.; Guillemot, L.; Hessels, J. W. T.; Hobbs, G.; Janssen, G. H.; Jones, G.; Karuppusamy, R.; Keith, M.; Kerr, M.; Kramer, M.; Lam, M. T.; Lasky, P. D.; Lassus, A.; Lazarus, P.; Lazio, T. J. W.; Lee, K. J.; Levin, L.; Liu, K.; Lynch, R. S.; Madison, D. R.; McKee, J.; McLaughlin, M.; McWilliams, S. T.; Mingarelli, C. M. F.; Nice, D. J.; Osłowski, S.; Pennucci, T. T.; Perera, B. B. P.; Perrodin, D.; Petiteau, A.; Possenti, A.; Ransom, S. M.; Reardon, D.; Rosado, P. A.; Sanidas, S. A.; Sesana, A.; Shaifullah, G.; Siemens, X.; Smits, R.; Stairs, I.; Stappers, B.; Stinebring, D. R.; Stovall, K.; Swiggum, J.; Taylor, S. R.; Theureau, G.; Tiburzi, C.; Toomey, L.; Vallisneri, M.; van Straten, W.; Vecchio, A.; Wang, J.-B.; Wang, Y.; You, X. P.; Zhu, W. W.; Zhu, X.-J.

    2016-05-01

    We analyse the stochastic properties of the 49 pulsars that comprise the first International Pulsar Timing Array (IPTA) data release. We use Bayesian methodology, performing model selection to determine the optimal description of the stochastic signals present in each pulsar. In addition to spin-noise and dispersion-measure (DM) variations, these models can include timing noise unique to a single observing system, or frequency band. We show the improved radio-frequency coverage and presence of overlapping data from different observing systems in the IPTA data set enables us to separate both system and band-dependent effects with much greater efficacy than in the individual pulsar timing array (PTA) data sets. For example, we show that PSR J1643-1224 has, in addition to DM variations, significant band-dependent noise that is coherent between PTAs which we interpret as coming from time-variable scattering or refraction in the ionized interstellar medium. Failing to model these different contributions appropriately can dramatically alter the astrophysical interpretation of the stochastic signals observed in the residuals. In some cases, the spectral exponent of the spin-noise signal can vary from 1.6 to 4 depending upon the model, which has direct implications for the long-term sensitivity of the pulsar to a stochastic gravitational-wave (GW) background. By using a more appropriate model, however, we can greatly improve a pulsar's sensitivity to GWs. For example, including system and band-dependent signals in the PSR J0437-4715 data set improves the upper limit on a fiducial GW background by ˜60 per cent compared to a model that includes DM variations and spin-noise only.

  20. Falling Person Detection Using Multi-Sensor Signal Processing

    NASA Astrophysics Data System (ADS)

    Toreyin, B. Ugur; Soyer, A. Birey; Onaran, Ibrahim; Cetin, E. Enis

    2007-12-01

    Falls are one of the most important problems for frail and elderly people living independently. Early detection of falls is vital to provide a safe and active lifestyle for elderly. Sound, passive infrared (PIR) and vibration sensors can be placed in a supportive home environment to provide information about daily activities of an elderly person. In this paper, signals produced by sound, PIR and vibration sensors are simultaneously analyzed to detect falls. Hidden Markov Models are trained for regular and unusual activities of an elderly person and a pet for each sensor signal. Decisions of HMMs are fused together to reach a final decision.

  1. Sequential growth of zinc oxide nanorod arrays at room temperature via a corrosion process: application in visible light photocatalysis.

    PubMed

    Iqbal, Danish; Kostka, Aleksander; Bashir, Asif; Sarfraz, Adnan; Chen, Ying; Wieck, Andreas D; Erbe, Andreas

    2014-11-12

    Many photocatalyst systems catalyze chemical reactions under ultraviolet (UV) illumination, because of its high photon energies. Activating inexpensive, widely available materials as photocatalyst using the intense visible part of the solar spectrum is more challenging. Here, nanorod arrays of the wide-band-gap semiconductor zinc oxide have been shown to act as photocatalysts for the aerobic photo-oxidation of organic dye Methyl Orange under illumination with red light, which is normally accessible only to narrow-band semiconductors. The homogeneous, 800-1000-nm-thick ZnO nanorod arrays show substantial light absorption (absorbances >1) throughout the visible spectral range. This absorption is caused by defect levels inside the band gap. Multiple scattering processes by the rods make the nanorods appear black. The dominantly crystalline ZnO nanorod structures grow in the (0001) direction, i.e., with the c-axis perpendicular to the surface of polycrystalline zinc. The room-temperature preparation route relies on controlled cathodic delamination of a weakly bound polymer coating from metallic zinc, an industrially produced and cheaply available substrate. Cathodic delamination is a sequential synthesis process, because it involves the propagation of a delamination front over the base material. Consequently, arbitrarily large sample surfaces can be nanostructured using this approach.

  2. Runtimes for tests of array-processing speed: Factorial tests using C and C++ under Windows and Linux

    USGS Publications Warehouse

    Donato, David I.

    2017-01-01

    The dataset is provided as a .zip archive containing two .csv data files. These two data files contain the results of a series of timing runs made with a suite of 28 C test programs and 20 C++ test programs using three different computers and two operating systems (Windows and Linux). All 48 test programs carry out processing of two-dimensional arrays. One of the files, "C_CppTimeTestsAllRecords.csv", contains three replicated times for each of 960 combinations of factor levels that potentially might have affected the time required to process two-dimensional arrays. The other file, "C_CppTimeTestsAverages.csv", contains the average of the three replicated times for each of the 960 combinations of factor levels. Both files have the same column headers and data formats, and the meaning of the data fields (columns) is the same in both files, with one exception. The exception is that the file for all records contains actual runtimes (in seconds) in the "ProcTime" field, whereas the other file contains averaged runtimes in the "ProcTime" field.

  3. RadMAP: The Radiological Multi-sensor Analysis Platform

    NASA Astrophysics Data System (ADS)

    Bandstra, Mark S.; Aucott, Timothy J.; Brubaker, Erik; Chivers, Daniel H.; Cooper, Reynold J.; Curtis, Joseph C.; Davis, John R.; Joshi, Tenzing H.; Kua, John; Meyer, Ross; Negut, Victor; Quinlan, Michael; Quiter, Brian J.; Srinivasan, Shreyas; Zakhor, Avideh; Zhang, Richard; Vetter, Kai

    2016-12-01

    The variability of gamma-ray and neutron background during the operation of a mobile detector system greatly limits the ability of the system to detect weak radiological and nuclear threats. The natural radiation background measured by a mobile detector system is the result of many factors, including the radioactivity of nearby materials, the geometric configuration of those materials and the system, the presence of absorbing materials, and atmospheric conditions. Background variations tend to be highly non-Poissonian, making it difficult to set robust detection thresholds using knowledge of the mean background rate alone. The Radiological Multi-sensor Analysis Platform (RadMAP) system is designed to allow the systematic study of natural radiological background variations and to serve as a development platform for emerging concepts in mobile radiation detection and imaging. To do this, RadMAP has been used to acquire extensive, systematic background measurements and correlated contextual data that can be used to test algorithms and detector modalities at low false alarm rates. By combining gamma-ray and neutron detector systems with data from contextual sensors, the system enables the fusion of data from multiple sensors into novel data products. The data are curated in a common format that allows for rapid querying across all sensors, creating detailed multi-sensor datasets that are used to study correlations between radiological and contextual data, and develop and test novel techniques in mobile detection and imaging. In this paper we will describe the instruments that comprise the RadMAP system, the effort to curate and provide access to multi-sensor data, and some initial results on the fusion of contextual and radiological data.

  4. Multisensor fusion with non-optimal decision rules: the challenges of open world sensing

    NASA Astrophysics Data System (ADS)

    Minor, Christian; Johnson, Kevin

    2014-05-01

    In this work, simple, generic models of chemical sensing are used to simulate sensor array data and to illustrate the impact on overall system performance that specific design choices impart. The ability of multisensor systems to perform multianalyte detection (i.e., distinguish multiple targets) is explored by examining the distinction between fundamental design-related limitations stemming from mismatching of mixture composition to fused sensor measurement spaces, and limitations that arise from measurement uncertainty. Insight on the limits and potential of sensor fusion to robustly address detection tasks in realistic field conditions can be gained through an examination of a) the underlying geometry of both the composition space of sources one hopes to elucidate and the measurement space a fused sensor system is capable of generating, and b) the informational impact of uncertainty on both of these spaces. For instance, what is the potential impact on sensor fusion in an open world scenario where unknown interferants may contaminate target signals? Under complex and dynamic backgrounds, decision rules may implicitly become non-optimal and adding sensors may increase the amount of conflicting information observed. This suggests that the manner in which a decision rule handles sensor conflict can be critical in leveraging sensor fusion for effective open world sensing, and becomes exponentially more important as more sensors are added. Results and design considerations for handling conflicting evidence in Bayes and Dempster-Shafer fusion frameworks are presented. Bayesian decision theory is used to provide an upper limit on detector performance of simulated sensor systems.

  5. The use of multisensor images for Earth Science applications

    NASA Technical Reports Server (NTRS)

    Evans, D.; Stromberg, B.

    1983-01-01

    The use of more than one remote sensing technique is particularly important for Earth Science applications because of the compositional and textural information derivable from the images. The ability to simultaneously analyze images acquired by different sensors requires coregistration of the multisensor image data sets. In order to insure pixel to pixel registration in areas of high relief, images must be rectified to eliminate topographic distortions. Coregistered images can be analyzed using a variety of multidimensional techniques and the acquired knowledge of topographic effects in the images can be used in photogeologic interpretations.

  6. Multi-sensor integration on the NCUBE hypercube computer

    SciTech Connect

    Glover, C.W.

    1988-01-01

    This paper presents the quantitative performance results obtained from converting a large sequential Multi-Sensor Integration (MSI) program into aconcurrent form, and executing the program on an NCUBE hypercube computer for several test case scenarios. Each sensor track was assigned to a different node of the hypercube where computationally intensive calculations were performed. A 4-mode hypercube was found to be the optimal size for the test case scenario discussed here, where speed-up factors of 1.5 to 1.7 were obtained. A completely concurrent MSI algorithm is also presented. 1 ref., 9 figs.

  7. Satellite Data Simulator Unit: A Multisensor, Multispectral Satellite Simulator Package

    NASA Technical Reports Server (NTRS)

    Masunaga, Hirohiko; Matsui, Toshihisa; Tao, Wei-Kuo; Hou, Arthur Y.; Kummerow, Christian D.; Nakajima, Teruyuki; Bauer, Peter; Olson, William S.; Sekiguchi, Miho; Nakajima, Teruyuki

    2010-01-01

    Several multisensor simulator packages are being developed by different research groups across the world. Such simulator packages [e.g., COSP , CRTM, ECSIM, RTTO, ISSARS (under development), and SDSU (this article), among others] share overall aims, although some are targeted more on particular satellite programs or specific applications (for research purposes or for operational use) than others. The SDSU or Satellite Data Simulator Unit is a general-purpose simulator composed of Fortran 90 codes and applicable to spaceborne microwave radiometer, radar, and visible/infrared imagers including, but not limited to, the sensors listed in a table. That shows satellite programs particularly suitable for multisensor data analysis: some are single satellite missions carrying two or more instruments, while others are constellations of satellites flying in formation. The TRMM and A-Train are ongoing satellite missions carrying diverse sensors that observe clouds and precipitation, and will be continued or augmented within the decade to come by future multisensor missions such as the GPM and Earth-CARE. The ultimate goals of these present and proposed satellite programs are not restricted to clouds and precipitation but are to better understand their interactions with atmospheric dynamics/chemistry and feedback to climate. The SDSU's applicability is not technically limited to hydrometeor measurements either, but may be extended to air temperature and humidity observations by tuning the SDSU to sounding channels. As such, the SDSU and other multisensor simulators would potentially contribute to a broad area of climate and atmospheric sciences. The SDSU is not optimized to any particular orbital geometry of satellites. The SDSU is applicable not only to low-Earth orbiting platforms as listed in Table 1, but also to geostationary meteorological satellites. Although no geosynchronous satellite carries microwave instruments at present or in the near future, the SDSU would be

  8. A Bayesian tracker for multi-sensor passive narrowband fusion

    NASA Astrophysics Data System (ADS)

    Pirkl, Ryan J.; Aughenbaugh, Jason M.

    2016-05-01

    We demonstrate the detection and localization performance of a multi-sensor, passive sonar Bayesian tracker for underwater targets emitting narrowband signals in the presence of realistic underwater ambient noise. Our evaluation focuses on recent advances in the formulation of the likelihood function used by the tracker that provide greater robustness in the presence of both realistic environmental noise and imprecise/inaccurate a priori knowledge of the target's narrowband signal. These improvements enable the tracker to reliably detect and localize narrowband emitters for a broader range of propagation environments, target velocities, and inherent uncertainty in a priori knowledge.

  9. Satellite Data Simulator Unit: A Multisensor, Multispectral Satellite Simulator Package

    NASA Technical Reports Server (NTRS)

    Masunaga, Hirohiko; Matsui, Toshihisa; Tao, Wei-Kuo; Hou, Arthur Y.; Kummerow, Christian D.; Nakajima, Teruyuki; Bauer, Peter; Olson, William S.; Sekiguchi, Miho; Nakajima, Teruyuki

    2010-01-01

    Several multisensor simulator packages are being developed by different research groups across the world. Such simulator packages [e.g., COSP , CRTM, ECSIM, RTTO, ISSARS (under development), and SDSU (this article), among others] share overall aims, although some are targeted more on particular satellite programs or specific applications (for research purposes or for operational use) than others. The SDSU or Satellite Data Simulator Unit is a general-purpose simulator composed of Fortran 90 codes and applicable to spaceborne microwave radiometer, radar, and visible/infrared imagers including, but not limited to, the sensors listed in a table. That shows satellite programs particularly suitable for multisensor data analysis: some are single satellite missions carrying two or more instruments, while others are constellations of satellites flying in formation. The TRMM and A-Train are ongoing satellite missions carrying diverse sensors that observe clouds and precipitation, and will be continued or augmented within the decade to come by future multisensor missions such as the GPM and Earth-CARE. The ultimate goals of these present and proposed satellite programs are not restricted to clouds and precipitation but are to better understand their interactions with atmospheric dynamics/chemistry and feedback to climate. The SDSU's applicability is not technically limited to hydrometeor measurements either, but may be extended to air temperature and humidity observations by tuning the SDSU to sounding channels. As such, the SDSU and other multisensor simulators would potentially contribute to a broad area of climate and atmospheric sciences. The SDSU is not optimized to any particular orbital geometry of satellites. The SDSU is applicable not only to low-Earth orbiting platforms as listed in Table 1, but also to geostationary meteorological satellites. Although no geosynchronous satellite carries microwave instruments at present or in the near future, the SDSU would be

  10. Fault detection and isolation for multisensor navigation systems

    NASA Technical Reports Server (NTRS)

    Kline, Paul A.; Vangraas, Frank

    1991-01-01

    Increasing attention is being given to the problem of erroneous measurement data for multisensor navigation systems. A recursive estimator can be used in conjunction with a 'snapshot' batch estimator to provide fault detection and isolation (FDI) for these systems. A recursive estimator uses past system states to form a new state estimate and compares it to the calculated state based on a new set of measurements. A 'snapshot' batch estimator uses a set of measurements collected simultaneously and compares solutions based on subsets of measurements. The 'snapshot' approach requires redundant measurements in order to detect and isolate faults. FDI is also referred to as Receiver Autonomous Integrity Monitoring (RAIM).

  11. Matched Bearing Processing for Airborne Source Localization by an Underwater Horizontal Line Array

    NASA Astrophysics Data System (ADS)

    Peng, Zhao-Hui; Li, Zheng-Lin; Wang, Guang-Xu

    2010-11-01

    Location of an airborne source is estimated from signals measured by a horizontal line array (HLA), based on the fact that a signal transmitted by an airborne source will reach a underwater hydrophone in different ways: via a direct refracted path, via one or more bottom and surface reflections, via the so-called lateral wave. As a result, when an HLA near the airborne source is used for beamforming, several peaks at different bearing angles will appear. By matching the experimental beamforming outputs with the predicted outputs for all source locations, the most likely location is the one which gives minimum difference. An experiment is conducted for airborne source localization in the Yellow Sea in October 2008. An HLA was laid on the sea bottom at the depth of 30m. A high-power loudspeaker was hung on a research ship floating near the HLA and sent out LFM pulses. The estimated location of the loudspeaker is in agreement well with the GPS measurements.

  12. Low cost solar array project production process and equipment task. A Module Experimental Process System Development Unit (MEPSDU)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Technical readiness for the production of photovoltaic modules using single crystal silicon dendritic web sheet material is demonstrated by: (1) selection, design and implementation of solar cell and photovoltaic module process sequence in a Module Experimental Process System Development Unit; (2) demonstration runs; (3) passing of acceptance and qualification tests; and (4) achievement of a cost effective module.

  13. Focal plane array with modular pixel array components for scalability

    SciTech Connect

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  14. Elastomeric inverse moulding and vacuum casting process characterization for the fabrication of arrays of concave refractive microlenses

    NASA Astrophysics Data System (ADS)

    Desmet, L.; Van Overmeire, S.; Van Erps, J.; Ottevaere, H.; Debaes, C.; Thienpont, H.

    2007-01-01

    We present a complete and precise quantitative characterization of the different process steps used in an elastomeric inverse moulding and vacuum casting technique. We use the latter replication technique to fabricate concave replicas from an array of convex thermal reflow microlenses. During the inverse elastomeric moulding we obtain a secondary silicone mould of the original silicone mould in which the master component is embedded. Using vacuum casting, we are then able to cast out of the second mould several optical transparent poly-urethane arrays of concave refractive microlenses. We select ten particular representative microlenses on the original, the silicone moulds and replica sample and quantitatively characterize and statistically compare them during the various fabrication steps. For this purpose, we use several state-of-the-art and ultra-precise characterization tools such as a stereo microscope, a stylus surface profilometer, a non-contact optical profilometer, a Mach-Zehnder interferometer, a Twyman-Green interferometer and an atomic force microscope to compare various microlens parameters such as the lens height, the diameter, the paraxial focal length, the radius of curvature, the Strehl ratio, the peak-to-valley and the root-mean-square wave aberrations and the surface roughness. When appropriate, the microlens parameter under test is measured with several different measuring tools to check for consistency in the measurement data. Although none of the lens samples shows diffraction-limited performance, we prove that the obtained replicated arrays of concave microlenses exhibit sufficiently low surface roughness and sufficiently high lens quality for various imaging applications.

  15. Investigation of proposed process sequence for the array automated assembly task, phases 1 and 2

    NASA Technical Reports Server (NTRS)

    Mardesich, N.; Garcia, A.; Eskenas, K.

    1980-01-01

    Progress was made on the process sequence for module fabrication. A shift from bonding with a conformal coating to laminating with ethylene vinyl acetate and a glass superstrate is recommended for further module fabrication. The processes that were retained for the selected process sequence, spin-on diffusion, print and fire aluminum p+ back, clean, print and fire silver front contact and apply tin pad to aluminum back, were evaluated for their cost contribution.

  16. Synthesis of Ferroelectric Lead Titanate Nanohoneycomb Arrays via Lead Supplement Process

    SciTech Connect

    Kim, Bongsoo; Hong, Seungbum; Ahn, Gun; No, Kwangsoo

    2016-05-14

    In this paper, we demonstrate a novel process to convert TiO2 nanotubes into ferroelectric nanohoneycombs, comprised of vertically aligned PbTiO3 nanotubes. Tube bottom opening process enabled effective infiltration of lead acetate precursor into the nanotubes. Finally, nanohoneycombs, which were converted via additional lead supplement process, showed uniform conversion and well-defined ferroelectric properties with the effective piezoelectric coefficient of approximately 20 pm/V, which was measured by piezoresponse force microscopy.

  17. Synthesis of Ferroelectric Lead Titanate Nanohoneycomb Arrays via Lead Supplement Process

    DOE PAGES

    Kim, Bongsoo; Hong, Seungbum; Ahn, Gun; ...

    2016-05-14

    In this paper, we demonstrate a novel process to convert TiO2 nanotubes into ferroelectric nanohoneycombs, comprised of vertically aligned PbTiO3 nanotubes. Tube bottom opening process enabled effective infiltration of lead acetate precursor into the nanotubes. Finally, nanohoneycombs, which were converted via additional lead supplement process, showed uniform conversion and well-defined ferroelectric properties with the effective piezoelectric coefficient of approximately 20 pm/V, which was measured by piezoresponse force microscopy.

  18. What can hafnium isotope ratios arrays tell us about orogenic processes? An insight into geodynamic processes operating in the Alpine/Mediterranean region

    NASA Astrophysics Data System (ADS)

    Henderson, B.; Murphy, J.; Collins, W. J.; Hand, M. P.

    2013-12-01

    Over the last decade, technological advances in laser-ablation sampling techniques have resulted in an increase in the number of combined U-Pb-Hf zircon isotope studies used to investigate crustal evolution on a local, regional and global scale. Hafnium isotope arrays over large time scales (>500 myr) have been interpreted to track evolving plate tectonic configurations, and the geological outputs associated with changing plate boundaries. We use the Alpine-Mediterranean region as an example of how hafnium isotope arrays record the geodynamic processes associated with the complex geological evolution of a region. The geology of Alpine-Mediterranean region preserves a complex, semi-continuous tectonic history that extends from the Neoproterozoic to the present day. Major components of the Variscan and Alpine orogens are microcontinental ribbons derived from the northern Gondwanan margin, which were transferred to the Eurasian plate during the opening and closing of the Rheic and Paleo-Tethys Oceans. Convergence of the Eurasian and African plates commenced in the Mid-Late Cretaceous, following the destruction of the Alpine-Tethys Ocean during the terminal breakup of Pangea. In general, convergence occurred slowly and is characterised by northward accretion of Gondwanan fragments, interspersed with subduction of African lithosphere and intermittent roll-back events. A consequence of this geodynamic scenario was periods of granite-dominated magmatism in an arc-backarc setting. New Hf isotope data from the peri-Gondwanan terranes (Iberia, Meguma and Avalonia) and a compilation of existing Phanerozoic data from the Alpine-Mediterranean region, indicate ~500 myr (Cambrian-Recent) of reworking of peri-Gondwanan crust. The eHf array follows a typical crustal evolution pattern (Lu/Hf=0.015) and is considered to reflect reworking of juvenile peri-Gondwanan (Neoproterozoic) crust variably mixed with an older (~1.8-2.0 Ga) source component, probably Eburnian crust from the West

  19. Research and development of low cost processes for integrated solar arrays

    NASA Technical Reports Server (NTRS)

    Wolf, M.; Crossman, L. D.

    1975-01-01

    Si reduction, purification and sheet generation work has been concentrated on gaining information about a reduction process combined with purification (higher purity arc furnace with gas blowing and gradient freezing), transport process with purification and polycrystal sheet growth potential (SiF2), plastic deformation for sheet generation, and float zone sheet recrystallization.

  20. Fabrication and evaluation of a microspring contact array using a reel-to-reel continuous fiber process

    NASA Astrophysics Data System (ADS)

    Khumpuang, S.; Ohtomo, A.; Miyake, K.; Itoh, T.

    2011-10-01

    In this work a novel patterning technique for fabrication of a conductive microspring array as an electrical contact structure directly on fiber substrate is introduced. Using low-temperature compression from the nanoimprinting technique to generate a gradient depth on the desired pattern, PEDOT: PSS film, the hair-like structures are released as bimorph microspring cantilevers. The microspring is in the form of a stress-engineered cantilever arranged in rows. The microspring contact array is employed in composing the electrical circuit through a large area of woven textile, and functions as the electrical contact between weft ribbon and warp ribbon. The spring itself has a contact resistance of 480 Ω to the plain PEDOT:PSS-coated ribbon, which shows a promising electrical transfer ability within the limitations of materials employed for reel-to-reel continuous processes. The microspring contact structures enhanced the durability, flexibility and stability of electrical contact in the woven textile better than those of the ribbons without the microspring. The contact experiment was repeated over 500 times, losing only 20 Ω of the resistance. Furthermore, to realize the spring structure, CYTOP is used as the releasing layer due to its low adhesive force to the fiber substrate. Moreover the first result of patternable CYTOP using nano-imprinting lithography is included.