Science.gov

Sample records for high-dynamic range multi-gene

  1. Scaling of Nucleic Acid Assays on Microelectrophoresis Array Devices: High-Dynamic Range Multi-gene Readout from less than 10 Transcripts

    PubMed Central

    Ueberfeld, Joern; Ehrlich, Daniel J.

    2009-01-01

    In this paper we describe progress in using the prodigious data-collecting ability of multilane microelectrophoresis instruments to bear on problems in scaled nucleic acid assays. We emphasize compound stacking and Solid-Support loading as means to concentrate <100 pg samples for direct injection. Reaction Mapping is applied to readout of quantitative polymerase chain reaction (qPCR) gene-expression and as a way to practically overcome difficulty in interpreting amplification curves of multiplexed qPCR at 20–50 gene/well complexity. We demonstrate multiplexed readout of gene expression over an abundancy range of 9Log2 units starting with reverse-transcribed samples as small as 5 molecules in each sample. PMID:19544490

  2. Shadow Attenuation With High Dynamic Range Images

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shadow often interferes with accurate image analysis. To mitigate shadow effects in near-earth imagery (2 m above ground level), we created high dynamic range (HDR) nadir images and used them to measure grassland ground cover. HDR composites were created by merging three differentially-exposed image...

  3. High dynamic range holographic data storage media

    NASA Astrophysics Data System (ADS)

    Askham, Fred; Ayres, Mark R.; Urness, Adam C.

    2015-08-01

    Holographic data storage (HDS) employs the physics of holography to record digital data in three dimensions in a highly stable photopolymer medium. The photopolymer medium must provide the essential characteristics of low scatter and high dynamic range while maintaining low recording induced physical shrinkage and long archival lifetimes. In this article, we report on media advancements employing Akonia's DREDTM technology which provide a 5x increase in media dynamic range with unchanged media shrinkage. We also discuss the implications of these results for photopolymer media mechanistic models.

  4. EMIR high-dynamic range readout modes

    NASA Astrophysics Data System (ADS)

    Nuñez, Miguel; Gago, Fernando; Garzón, Francisco; Díaz, José J.; Barreto, Mary; Patrón, Jesús; González-Fenández, Carlos; Hammersley, Peter L.; López, Luis; Castro, Nieves

    2012-07-01

    EMIR is the NIR imager and multiobject spectrograph being built as a common user instrument for the GTC and it is currently entering in the integration and verification phase at system level. EMIR is being built by a Consortium of Spanish and French institutes led by the IAC. In this paper we describe the readout modes of EMIR detector, a Hawaii2 FPA, after two full calibrations campaigns. Besides the standard set of modes (reset-read, CDS, Fowler, Follow-up the ramp), the modified SDSU-III hardware and home made software will also offer high dynamic range readout modes, which will improve the ability of the instrument to sound densely populated areas which often are made of objects with large differences in brightness. These new high dynamic range modes are: single readout with very short integration time, window mode and combination of both. The results show that the new modes behave linearly with different exposition times, improve the maximum frame rate and increase the saturation limit in image mode for EMIR instrument.

  5. High-dynamic-range MCP structures

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. G.

    1991-01-01

    We report on the development of a new high-dynamic-range two-stage Multi-Anode Microchannel Array (MAMA) imaging tube designed for improved high count rate performance at FUV and EUV wavelengths. The new two-stage MAMA tube employs two 25-mm-diameter format MCPs placed in tandem with a small gap between the plates. The front (input) MCP is designed to be a low-gain converter plate that supports an opaque photocathode and converts the detected photons to electrons, while the second (output) MCP is of higher conductivity and thus maintains the overall gain of the multiplier at high count rates. The second MCP is mounted in proximity focus with a (224 x 960)-pixel fine-fine coincidence MAMA array for high-spatial-resolution imaging studies. The applied voltage across each MCP can be controlled independently. We report on the gain and dynamic range performance characteristics of the two-stage MAMA tube in two different configurations: first, with the output MCP having moderate conductivity (about 100 MOhm); and second, with the output MCP having very high conductivity (about 2 MOhm). These results are compared and contrasted with those of the more conventional MAMA tube configuration which employs a single high-gain curved-channel MCP.

  6. High Dynamic Range Digital Imaging of Spacecraft

    NASA Technical Reports Server (NTRS)

    Karr, Brian A.; Chalmers, Alan; Debattista, Kurt

    2014-01-01

    The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume.

  7. High dynamic range infrared radiometry and imaging

    NASA Technical Reports Server (NTRS)

    Coon, Darryl D.; Karunasiri, R. P. G.; Bandara, K. M. S. V.

    1988-01-01

    The use is described of cryogenically cooled, extrinsic silicon infrared detectors in an unconventional mode of operation which offers an unusually large dynamic range. The system performs intensity-to-frequency conversion at the focal plane via simple circuits with very low power consumption. The incident IR intensity controls the repetition rate of short duration output pulses over a pulse rate dynamic range of about 10(6). Theory indicates the possibility of monotonic and approx. linear response over the full dynamic range. A comparison between the theoretical and the experimental results shows that the model provides a reasonably good description of experimental data. Some measurements of survivability with a very intense IR source were made on these devices and found to be very encouraging. Evidence continues to indicate that some variations in interpulse time intervals are deterministic rather than probabilistic.

  8. High dynamic range Josephson parametric amplifiers

    NASA Astrophysics Data System (ADS)

    Roch, Nicolas; Murch, Kater W.; Vijay, Rajamani

    Josephson parametric amplifiers (JPAs) have become the technology of choice to amplify small amplitude microwave signals since they show noise performances close to the quantum limit of amplification. An important challenge that faces this technology is the low dynamic range of current devices, which limits the number of measurements that can be performed concurrently and the rate of information acquisition for single measurements. We have fabricated and tested novel parametric amplifiers based on arrays of up to 100 SQUIDS. The amplifiers produce gain in excess of 20 dB over a large bandwidth and match the dynamic range achieved with traveling wave devices. Compared to the latter devices they are fabricated in a single lithography step and we will show that their bandwidth performance can be further extended using a recently developed impedance matching technique.

  9. Real-time high dynamic range laser scanning microscopy

    PubMed Central

    Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

    2016-01-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging. PMID:27032979

  10. Real-time high dynamic range laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

    2016-04-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

  11. Evaluation of color encodings for high dynamic range pixels

    NASA Astrophysics Data System (ADS)

    Boitard, Ronan; Mantiuk, Rafal K.; Pouli, Tania

    2015-03-01

    Traditional Low Dynamic Range (LDR) color spaces encode a small fraction of the visible color gamut, which does not encompass the range of colors produced on upcoming High Dynamic Range (HDR) displays. Future imaging systems will require encoding much wider color gamut and luminance range. Such wide color gamut can be represented using floating point HDR pixel values but those are inefficient to encode. They also lack perceptual uniformity of the luminance and color distribution, which is provided (in approximation) by most LDR color spaces. Therefore, there is a need to devise an efficient, perceptually uniform and integer valued representation for high dynamic range pixel values. In this paper we evaluate several methods for encoding colour HDR pixel values, in particular for use in image and video compression. Unlike other studies we test both luminance and color difference encoding in a rigorous 4AFC threshold experiments to determine the minimum bit-depth required. Results show that the Perceptual Quantizer (PQ) encoding provides the best perceptual uniformity in the considered luminance range, however the gain in bit-depth is rather modest. More significant difference can be observed between color difference encoding schemes, from which YDuDv encoding seems to be the most efficient.

  12. Shadow correction in high dynamic range images for generating orthophotos

    NASA Astrophysics Data System (ADS)

    Suzuki, Hideo; Chikatsu, Hirofumi

    2011-07-01

    High dynamic range imagery is widely used in remote sensing. With the widespread use of aerial digital cameras such as the DMC, ADS40, RMK-D, and UltraCamD, high dynamic range imaging is generally expected for generating minuteness orthophotos in digital aerial photogrammetry. However, high dynamic range images (12-bit, 4,096 gray levels) are generally compressed into an 8-bit depth digital image (256 gray levels) owing to huge amount of data and interface with peripherals such as monitors and printers. This means that a great deal of image data is eliminated from the original image, and this introduces a new shadow problem. In particular, the influence of shadows in urban areas causes serious problems when generating minuteness orthophotos and performing house detection. Therefore, shadow problems can be solved by addressing the image compression problems. There is a large body of literature on image compression techniques such as logarithmic compression and tone mapping algorithms. However, logarithmic compression tends to cause loss of details in dark and/or light areas. Furthermore, the logarithmic method intends to operate on the full scene. This means that high-resolution luminance information can not be obtained. Even though tone mapping algorithms have the ability to operate over both full scene and local scene, background knowledge is required. To resolve the shadow problem in digital aerial photogrammetry, shadow areas should be recognized and corrected automatically without the loss of luminance information. To this end, a practical shadow correction method using 12-bit real data acquired by DMC is investigated in this paper.

  13. High dynamic range image display with halo and clipping prevention.

    PubMed

    Guarnieri, Gabriele; Marsi, Stefano; Ramponi, Giovanni

    2011-05-01

    The dynamic range of an image is defined as the ratio between the highest and the lowest luminance level. In a high dynamic range (HDR) image, this value exceeds the capabilities of conventional display devices; as a consequence, dedicated visualization techniques are required. In particular, it is possible to process an HDR image in order to reduce its dynamic range without producing a significant change in the visual sensation experienced by the observer. In this paper, we propose a dynamic range reduction algorithm that produces high-quality results with a low computational cost and a limited number of parameters. The algorithm belongs to the category of methods based upon the Retinex theory of vision and was specifically designed in order to prevent the formation of common artifacts, such as halos around the sharp edges and clipping of the highlights, that often affect methods of this kind. After a detailed analysis of the state of the art, we shall describe the method and compare the results and performance with those of two techniques recently proposed in the literature and one commercial software. PMID:21078576

  14. Use of high dynamic range imaging for quantitative combustion diagnostics.

    PubMed

    Giassi, Davide; Liu, Bolun; Long, Marshall B

    2015-05-10

    High dynamic range (HDR) imaging is applied to quantitative combustion diagnostics in coflow laminar diffusion flames as a way to improve the signal-to-noise ratio (SNR) and measurement sensitivity. The technique relies on the combination of partially saturated frames into a single unsaturated image; in this work, the effectiveness of the HDR approach is demonstrated when applied to two-color ratio pyrometry. Specifically, it is shown than an increase in SNR results in more precise temperature measurements for both soot and thin filament pyrometry. Linearity and reciprocity analysis under partially saturated conditions were performed on three selected detectors, and the camera response functions, which are required for HDR image reconstruction, were determined. The linearity/reciprocity of the detectors allowed the use of a simplified algorithm that was implemented to compute the HDR images; soot and flame temperature were calculated from those images by employing color-ratio pyrometry. The reciprocity analysis revealed that pixel cross talk can be a limiting factor in a detector's HDR capabilities. The comparison with low dynamic range results showed the advantage of the HDR approach. Due to the higher SNR, the measured temperature exhibits a smoother distribution, and the range is extended to lower temperature regions, where the pyrometry technique starts to lose sensitivity due to detector limitations. PMID:25967519

  15. Joint focus stacking and high dynamic range imaging

    NASA Astrophysics Data System (ADS)

    Qian, Qinchun; Gunturk, Bahadir K.; Batur, Aziz U.

    2013-01-01

    Focus stacking and high dynamic range (HDR) imaging are two paradigms of computational photography. Focus stacking aims to produce an image with greater depth of field (DOF) from a set of images taken with different focus distances, whereas HDR imaging aims to produce an image with higher dynamic range from a set of images taken with different exposure settings. In this paper, we present an algorithm which combines focus stacking and HDR imaging in order to produce an image with both higher dynamic range and greater DOF than any of the input images. The proposed algorithm includes two main parts: (i) joint photometric and geometric registration and (ii) joint focus stacking and HDR image creation. In the first part, images are first photometrically registered using an algorithm that is insensitive to small geometric variations, and then geometrically registered using an optical flow algorithm. In the second part, images are merged through weighted averaging, where the weights depend on both local sharpness and exposure information. We provide experimental results with real data to illustrate the algorithm. The algorithm is also implemented on a smartphone with Android operating system.

  16. High-dynamic range DMD-based IR scene projector

    NASA Astrophysics Data System (ADS)

    Dupuis, Julia R.; Mansur, David J.; Vaillancourt, Robert; Benedict-Gill, Ryan; Newbry, Scott P.

    2013-03-01

    OPTRA is developing a next-generation digital micromirror device (DMD) based two-band infrared scene projector (IRSP) with infinite bit-depth independent of frame rate and an order of magnitude improvement in contrast over the state of the art. Traditionally DMD-based IRSPs have offered larger format and superior uniformity and pixel operability relative to resistive and diode arrays, however, they have been limited in contrast and also by the inherent bitdepth / frame rate tradeoff imposed by pulse width modulation (PWM). OPTRA's high dynamic range IRSP (HIDRA SP) has broken this dependency with a dynamic structured illumination solution. The HIDRA SP uses a source conditioning DMD to impose the structured illumination on two projector DMDs - one for each spectral band. The source conditioning DMD is operated in binary mode, and the relay optics which form the structured illumination act as a low pass spatial filter. The structured illumination is therefore spatially grayscaled and more importantly is analog with no PWM. In addition, the structured illumination concentrates energy where bright object will be projected and extinguishes energy in dark regions; the result is a significant improvement in contrast. The projector DMDs are operated with 8-bit PWM, however the total projected image is analog with no bit-depth / frame rate dependency. In this paper we describe our progress towards the development, build, and test of a prototype HIDRA SP.

  17. High-dynamic range DMD-based infrared scene projector

    NASA Astrophysics Data System (ADS)

    Mansur, David J.; Vaillancourt, Robert; Benedict-Gill, Ryan; Newbry, Scott P.; Rentz Dupuis, Julia

    2013-05-01

    OPTRA is developing a next-generation digital micromirror device (DMD) based two-band infrared scene projector (IRSP) with infinite bit-depth independent of frame rate and an order of magnitude improvement in contrast over the state of the art. Traditionally DMD-based IRSPs have offered larger format and superior uniformity and pixel operability relative to resistive and diode arrays, however, they have been limited in contrast and also by the inherent bitdepth / frame rate tradeoff imposed by pulse width modulation (PWM). OPTRA's high dynamic range IRSP (HIDRA SP) has broken this dependency with a dynamic structured illumination solution. The HIDRA SP uses a source conditioning DMD to impose the structured illumination on two projector DMDs - one for each spectral band. The source conditioning DMD is operated in binary mode, and the relay optics which form the structured illumination act as a low pass spatial filter. The structured illumination is therefore spatially grayscaled and more importantly is analog with no PWM. In addition, the structured illumination concentrates energy where bright object will be projected and extinguishes energy in dark regions; the result is a significant improvement in contrast. The projector DMDs are operated with 8-bit PWM, however the total projected image is analog with no bit-depth / frame rate dependency. In this paper we describe our progress towards the development, build, and test of a prototype HIDRA SP.

  18. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect

    Evtushenko, Pavel E.; Douglas, David R.

    2013-06-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  19. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect

    Evtushenko, Pavel; Douglas, David R.; Legg, Robert A.; Tennant, Christopher D.

    2013-05-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  20. Quantitative high dynamic range beam profiling for fluorescence microscopy

    SciTech Connect

    Mitchell, T. J. Saunter, C. D.; O’Nions, W.; Girkin, J. M.; Love, G. D.

    2014-10-15

    Modern developmental biology relies on optically sectioning fluorescence microscope techniques to produce non-destructive in vivo images of developing specimens at high resolution in three dimensions. As optimal performance of these techniques is reliant on the three-dimensional (3D) intensity profile of the illumination employed, the ability to directly record and analyze these profiles is of great use to the fluorescence microscopist or instrument builder. Though excitation beam profiles can be measured indirectly using a sample of fluorescent beads and recording the emission along the microscope detection path, we demonstrate an alternative approach where a miniature camera sensor is used directly within the illumination beam. Measurements taken using our approach are solely concerned with the illumination optics as the detection optics are not involved. We present a miniature beam profiling device and high dynamic range flux reconstruction algorithm that together are capable of accurately reproducing quantitative 3D flux maps over a large focal volume. Performance of this beam profiling system is verified within an optical test bench and demonstrated for fluorescence microscopy by profiling the low NA illumination beam of a single plane illumination microscope. The generality and success of this approach showcases a widely flexible beam amplitude diagnostic tool for use within the life sciences.

  1. High dynamic range imaging of non-static scenes

    NASA Astrophysics Data System (ADS)

    Hossain, Imtiaz; Gunturk, Bahadir K.

    2011-01-01

    A well-known technique in high dynamic range (HDR) imaging is to take multiple photographs, each one with a different exposure time, and then combine them to produce an HDR image. Unless the scene is static and the camera position is fixed, this process creates the so-called "ghosting" artifacts. In order to handle non-static scenes or moving camera, images have to be spatially registered. This is a challenging problem because most optical flow estimation algorithm depends on the constant brightness assumption, which is obviously not the case in HDR imaging. In this paper, we present an algorithm to estimate the dense motion field in image sequences with photometric variations. In an alternating optimization scheme, the algorithm estimates both the dense motion field and the photometric mapping. As a latent information, the occluded regions are extracted and excluded from the photometric mapping estimation. We include experiments with both synthetic and real imagery to demonstrate the efficacy of the proposed algorithm. We show that the ghosting artifacts are reduced significantly in HDR imaging of non-static scenes.

  2. Quantitative high dynamic range beam profiling for fluorescence microscopy.

    PubMed

    Mitchell, T J; Saunter, C D; O'Nions, W; Girkin, J M; Love, G D

    2014-10-01

    Modern developmental biology relies on optically sectioning fluorescence microscope techniques to produce non-destructive in vivo images of developing specimens at high resolution in three dimensions. As optimal performance of these techniques is reliant on the three-dimensional (3D) intensity profile of the illumination employed, the ability to directly record and analyze these profiles is of great use to the fluorescence microscopist or instrument builder. Though excitation beam profiles can be measured indirectly using a sample of fluorescent beads and recording the emission along the microscope detection path, we demonstrate an alternative approach where a miniature camera sensor is used directly within the illumination beam. Measurements taken using our approach are solely concerned with the illumination optics as the detection optics are not involved. We present a miniature beam profiling device and high dynamic range flux reconstruction algorithm that together are capable of accurately reproducing quantitative 3D flux maps over a large focal volume. Performance of this beam profiling system is verified within an optical test bench and demonstrated for fluorescence microscopy by profiling the low NA illumination beam of a single plane illumination microscope. The generality and success of this approach showcases a widely flexible beam amplitude diagnostic tool for use within the life sciences. PMID:25362409

  3. Joint high dynamic range imaging and color demosaicing

    NASA Astrophysics Data System (ADS)

    Herwig, Johannes; Pauli, Josef

    2011-11-01

    A non-parametric high dynamic range (HDR) fusion approach is proposed that works on raw images of single-sensor color imaging devices which incorporate the Bayer pattern. Thereby the non-linear opto-electronic conversion function (OECF) is recovered before color demosaicing, so that interpolation artifacts do not aect the photometric calibration. Graph-based segmentation greedily clusters the exposure set into regions of roughly constant radiance in order to regularize the OECF estimation. The segmentation works on Gaussian-blurred sensor images, whereby the articial gray value edges caused by the Bayer pattern are smoothed away. With the OECF known the 32-bit HDR radiance map is reconstructed by weighted summation from the dierently exposed raw sensor images. Because the radiance map contains lower sensor noise than the individual images, it is nally demosaiced by weighted bilinear interpolation which prevents the interpolation across edges. Here, the previous segmentation results from the photometric calibration are utilized. After demosaicing, tone mapping is applied, whereby remaining interpolation artifacts are further damped due to the coarser tonal quantization of the resulting image.

  4. Optimal exposure sets for high dynamic range scenes

    NASA Astrophysics Data System (ADS)

    Valli Kumari, V.; RaviKiran, B.; Raju, K. V. S. V. N.; Shajahan Basha, S. A.

    2011-10-01

    The dynamic range of many natural scenes is far greater than the dynamic range of the imaging devices. These scenes present a challenge to the consumer digital cameras. The well-known technique to capture the full dynamic range of the scene is by fusing multiple images of the same scene. Usually people combine three or five different exposures to get the full dynamic range of the scene. Some cameras like Pentax K-7, always combines fixed exposures together to produce the output result. However, this should be adaptive to the scene characteristics. We propose an optimal solution for dynamically selecting the exposure sets.

  5. NASA’s new High Dynamic Range Camera Records Rocket Test

    NASA Video Gallery

    This is footage of Orbital ATK’s QM-2 solid rocket booster test taken by NASA’s High Dynamic Range Stereo X (HiDyRS-X) camera. HiDyRS-X records high speed, high dynamic range footage in multiple ex...

  6. HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS

    SciTech Connect

    Deibele, Craig Edmond; Curry, Douglas E; Dickson, Richard W

    2012-01-01

    It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

  7. High Dynamic Range Characterization of the Trauma Patient Plasma Proteome

    SciTech Connect

    Liu, Tao; Qian, Weijun; Gritsenko, Marina A.; Xiao, Wenzhong; Moldawer, Lyle L.; Kaushal, Amit; Monroe, Matthew E.; Varnum, Susan M.; Moore, Ronald J.; Purvine, Samuel O.; Maier, Ronald V.; Davis, Ronald W.; Tompkins, Ronald G.; Camp, David G.; Smith, Richard D.

    2006-06-08

    While human plasma represents an attractive sample for disease biomarker discovery, the extreme complexity and large dynamic range in protein concentrations present significant challenges for characterization, candidate biomarker discovery, and validation. Herein, we describe a strategy that combines immunoaffinity subtraction and chemical fractionation based on cysteinyl peptide and N-glycopeptide captures with 2D-LC-MS/MS to increase the dynamic range of analysis for plasma. Application of this ''divide-and-conquer'' strategy to trauma patient plasma significantly improved the overall dynamic range of detection and resulted in confident identification of 22,267 unique peptides from four different peptide populations (cysteinyl peptides, non-cysteinyl peptides, N-glycopeptides, and non-glycopeptides) that covered 3654 nonredundant proteins. Numerous low-abundance proteins were identified, exemplified by 78 ''classic'' cytokines and cytokine receptors and by 136 human cell differentiation molecules. Additionally, a total of 2910 different N-glycopeptides that correspond to 662 N-glycoproteins and 1553 N-glycosylation sites were identified. A panel of the proteins identified in this study is known to be involved in inflammation and immune responses. This study established an extensive reference protein database for trauma patients, which provides a foundation for future high-throughput quantitative plasma proteomic studies designed to elucidate the mechanisms that underlie systemic inflammatory responses.

  8. High Dynamic Range Complex Impedance Measurement System for Petrophysical Usage

    NASA Astrophysics Data System (ADS)

    Chen, R.; He, X.; Yao, H.; Tan, S.; Shi, H.; Shen, R.; Yan, C.; Zeng, P.; He, L.; Qiao, N.; Xi, F.; Zhang, H.; Xie, J.

    2015-12-01

    Spectral induced polarization method (SIP) or complex resistivity method is increasing its application in metalliferous ore exploration, hydrocarbon exploration, underground water exploration, monitoring of environment pollution, and the evaluation of environment remediation. And the measurement of complex resistivity or complex impedance of rock/ore sample and polluted water plays a fundamental role in improving the application effect of SIP and the application scope of SIP. However, current instruments can't guaranty the accuracy of measurement when the resistance of sample is less than 10Ω or great than 100kΩ. A lot of samples, such as liquid, polluted sea water, igneous rock, limestone, and sandstone, can't be measured with reliable complex resistivity result. Therefore, this problem projects a shadow in the basic research and application research of SIP. We design a high precision measurement system from the study of measurement principle, sample holder, and measurement instrument. We design input buffers in a single board. We adopt operation amplifier AD549 in this system because of its ultra-high input impedance and ultra-low current noise. This buffer is good in acquiring potential signal across high impedance sample. By analyzing the sources of measurement error and errors generated by the measurement system, we propose a correction method to remove the error in order to achieve high quality complex impedance measurement for rock and ore samples. This measurement system can improve the measurement range of the complex impedance to 0.1 Ω ~ 10 GΩ with amplitude error less than 0.1% and phase error less than 0.1mrad when frequency ranges as 0.01 Hz ~ 1 kHz. We tested our system on resistors with resistance as 0.1Ω ~ 10 GΩ in frequency range as 1 Hz ~ 1000 Hz, and the measurement error is less than 0.1 mrad. We also compared the result with LCR bridge and SCIP, we can find that the bridge's measuring range only reaches 100 MΩ, SCIP's measuring range

  9. High dynamic range, hyper-terahertz detection with silicon photoconductors

    NASA Astrophysics Data System (ADS)

    Muir, A. C.; Hussain, A.; Andrews, S. R.

    2016-06-01

    The frequency response of ion implanted silicon photoconductive devices designed for coherent detection in time domain terahertz spectroscopy has been studied between 0.2 and 30 THz. Unlike devices using polar photoconductors or ones having polar substrates, which have a complicated response spectrum in the region of their reststrahlen bands, the response of silicon detectors fabricated on silicon substrates is relatively featureless. When used with amplified laser systems, the dynamic range of Si detectors is shown to be very similar to that of GaAs devices with the same geometry over a 20 THz range, superior to air-biased coherent detection (ABCD) at frequencies below ˜7 THz and comparable with both ABCD and electro-optic sampling in thin ZnTe crystals between 7 and 20 THz. Together with their ease of use and linear response in terahertz fields approaching 1 MV/cm, this suggests that Si photoconductors could be a competitive choice for sensitive detection in nonlinear hyper-terahertz spectroscopy.

  10. Alternating-Z tripler with high dynamic range

    SciTech Connect

    Eimerl, D.; Milam, D.

    1996-10-10

    A KD*P alternating-Z tripler suitable for NIF consists of two detuned Type I doublers and one aligned Type II mixer. The dynamic range for efficient tripling is predicted to be larger for this arrangement than for a standard 2-crystal tripler. We tested an alternating-Z tripler that had doublers with thicknesses of 13 and 10 mm, and a 10-mm-thick mixer. All of the crystals were 80% deuterated. The model of this tripler provided an excellent description of the efficiencies that were measured using pulses with duration of 1 or 6 ns. We confirmed the importance for alternating-Z triplers of controlling the phase differences arising from wavelength dispersion in the air gap between the doublers. The confirmed wide dynamic range of this arrangement is of interest for conversion of the 21-ns Haan pulse, or for conversion of beams with significant intensity fluctuations. Compensation for wavelength dispersion in the gap between the crystals is not an issue if the crystals are in vacuum.

  11. Image sensor with high dynamic range linear output

    NASA Technical Reports Server (NTRS)

    Yadid-Pecht, Orly (Inventor); Fossum, Eric R. (Inventor)

    2007-01-01

    Designs and operational methods to increase the dynamic range of image sensors and APS devices in particular by achieving more than one integration times for each pixel thereof. An APS system with more than one column-parallel signal chains for readout are described for maintaining a high frame rate in readout. Each active pixel is sampled for multiple times during a single frame readout, thus resulting in multiple integration times. The operation methods can also be used to obtain multiple integration times for each pixel with an APS design having a single column-parallel signal chain for readout. Furthermore, analog-to-digital conversion of high speed and high resolution can be implemented.

  12. High dynamic range coherent imaging using compressed sensing.

    PubMed

    He, Kuan; Sharma, Manoj Kumar; Cossairt, Oliver

    2015-11-30

    In both lensless Fourier transform holography (FTH) and coherent diffraction imaging (CDI), a beamstop is used to block strong intensities which exceed the limited dynamic range of the sensor, causing a loss in low-frequency information, making high quality reconstructions difficult or even impossible. In this paper, we show that an image can be recovered from high-frequencies alone, thereby overcoming the beamstop problem in both FTH and CDI. The only requirement is that the object is sparse in a known basis, a common property of most natural and manmade signals. The reconstruction method relies on compressed sensing (CS) techniques, which ensure signal recovery from incomplete measurements. Specifically, in FTH, we perform compressed sensing (CS) reconstruction of captured holograms and show that this method is applicable not only to standard FTH, but also multiple or extended reference FTH. For CDI, we propose a new phase retrieval procedure, which combines Fienup's hybrid input-output (HIO) method and CS. Both numerical simulations and proof-of-principle experiments are shown to demonstrate the effectiveness and robustness of the proposed CS-based reconstructions in dealing with missing data in both FTH and CDI. PMID:26698723

  13. High dynamic range video transmission and display using standard dynamic range technologies

    NASA Astrophysics Data System (ADS)

    Léonce, A.; Hsu, Tao-i.; Wickramanayake, D. S.; Edirisinghe, E. A.

    2012-06-01

    This paper presents a novel system that makes effective use of High Dynamic Range (HDR) image data to improve and maintain the best viewing quality of video broadcast on current mobile display devices. The proposed approach combines bilateral filtering with an adaptive tone mapping method used to enable the enhancement of the perceptual quality of the video frames at the display device. The bilateral filter separates the frame into large-scale and detail layers. The large-scale layer is divided into bright, mid-tone and dark regions, which are each processed by an appropriate tone mapping function. Ambient and backlight sensors at the display device provide information about current illumination conditions, which are used to intelligently and dynamically vary the levels and thresholds of post-processing applied at the decoder, thereby maintaining a constant level of perceived quality.

  14. Ultrafast Optical Beam Deflection in a Planar Waveguide for High Dynamic Range Recording at Picosecond Resolution

    SciTech Connect

    Sarantos, C H; Heebner, J E

    2008-07-02

    We report the latest performance of an ultrafast, all-optical beam deflector based on a prism array imprinted in a planar waveguide. The deflector enables single-shot, high dynamic range optical recording with picosecond resolution.

  15. Motion adaptive signal integration-high dynamic range (MASI-HDR) video processing for dynamic platforms

    NASA Astrophysics Data System (ADS)

    Piacentino, Michael R.; Berends, David C.; Zhang, David C.; Gudis, Eduardo

    2013-05-01

    Two of the biggest challenges in designing U×V vision systems are properly representing high dynamic range scene content using low dynamic range components and reducing camera motion blur. SRI's MASI-HDR (Motion Adaptive Signal Integration-High Dynamic Range) is a novel technique for generating blur-reduced video using multiple captures for each displayed frame while increasing the effective camera dynamic range by four bits or more. MASI-HDR processing thus provides high performance video from rapidly moving platforms in real-world conditions in low latency real time, enabling even the most demanding applications on air, ground and water.

  16. A gaze-contingent high-dynamic range display for medical imaging applications

    NASA Astrophysics Data System (ADS)

    Cheng, Wei-Chung; Badano, Aldo

    2010-02-01

    The grayscale resolution of current liquid crystal display technology limits its applications in medical imaging with wide dynamic range and dense grayscales are required. We propose an approach that dynamically processes the display image such that the luminance and contrast of the gazed area is optimized. A gazecontingent interactive display system based on an 8-bit LCD and an eye-tracker was implemented to emulate the proposed concept for a high-dynamic range display.

  17. High dynamic range imaging pipeline: perception-motivated representation of visual content

    NASA Astrophysics Data System (ADS)

    Mantiuk, Rafal; Krawczyk, Grzegorz; Mantiuk, Radoslaw; Seidel, Hans-Peter

    2007-02-01

    The advances in high dynamic range (HDR) imaging, especially in the display and camera technology, have a significant impact on the existing imaging systems. The assumptions of the traditional low-dynamic range imaging, designed for paper print as a major output medium, are ill suited for the range of visual material that is shown on modern displays. For example, the common assumption that the brightest color in an image is white can be hardly justified for high contrast LCD displays, not to mention next generation HDR displays, that can easily create bright highlights and the impression of self-luminous colors. We argue that high dynamic range representation can encode images regardless of the technology used to create and display them, with the accuracy that is only constrained by the limitations of the human eye and not a particular output medium. To facilitate the research on high dynamic range imaging, we have created a software package (http://pfstools.sourceforge.net/) capable of handling HDR data on all stages of image and video processing. The software package is available as open source under the General Public License and includes solutions for high quality image acquisition from multiple exposures, a range of tone mapping algorithms and a visual difference predictor for HDR images. Examples of shell scripts demonstrate how the software can be used for processing single images as well as video sequences.

  18. A high-dynamic range ROIC for SLS and other IR focal planes

    NASA Astrophysics Data System (ADS)

    Petilli, Eugene; Stern, Ken; TeWinkle, Scott

    2014-06-01

    In many high dynamic range applications, Sigma-Delta modulator (SDM) architectures have displaced most other architectures for analog to digital conversion (ADC). SDMs have not typically been applied to ROIC applications due to the interaction of spatial discontinuities and the temporal bandwidth limitation of the SDM. By using a novel serpentine readout sequence, we have reduced the temporal bandwidth and enabled application of SDM technology for high dynamic range Focal Plane Arrays (FPA). In addition, it is reconfigurable on-the-fly for a power vs. Signal to Noise plus Distortion Ratio (SNDR) tradeoff without "binning" or reducing the pixel pitch. This technique has been applied to enable low power foveal imaging. This reconfigurable ADC has been coupled with a low noise extended dynamic range photodiode input stages.

  19. Folded multiple-capture: an architecture for high dynamic range disturbance-tolerant focal plane array

    NASA Astrophysics Data System (ADS)

    Kavusi, Sam; El Gamal, Abbas

    2004-08-01

    Earlier studies have shown that multiple capture can achieve high SNR, but cannot satisfy the high dynamic range (HDR) and high speed requirements of the Vertically-Integrated-Sensor-Array (VISA) project. Synchronous self-reset, on the other hand, can achieve these requirements, but suffers from poor SNR. Extended counting can achieve high dynamic range at high frame rate and with good SNR, but at the expense of high power consumption. The paper proposes a new HDR focal plane array architecture, denoted by folded-multiple capture (FMC), which by combining features of the synchronous self-reset and multiple capture schemes, can satisfy the VISA requirements at a fraction of the power dissipation and with more robustness to device variations than extended counting. The architecture is also capable of detecting subframe disturbances, e.g., due to laser jamming, and correcting for it.

  20. A visibility matching tone reproduction operator for high dynamic range scenes

    SciTech Connect

    Larson, G.W.; Rushmeier, H.; Piatko, C.

    1997-01-15

    The authors present a tone reproduction operator that preserves visibility in high dynamic range scenes. The method introduces a new histogram adjustment technique, based on the population of local adaptation luminances in a scene. To match subjective viewing experience, the method incorporates models for human contrast sensitivity, glare, spatial acuity and color sensitivity. They compare the results to previous work and present examples the techniques applied to lighting simulation and electronic photography.

  1. An Analog Gamma Correction Scheme for High Dynamic Range CMOS Logarithmic Image Sensors

    PubMed Central

    Cao, Yuan; Pan, Xiaofang; Zhao, Xiaojin; Wu, Huisi

    2014-01-01

    In this paper, a novel analog gamma correction scheme with a logarithmic image sensor dedicated to minimize the quantization noise of the high dynamic applications is presented. The proposed implementation exploits a non-linear voltage-controlled-oscillator (VCO) based analog-to-digital converter (ADC) to perform the gamma correction during the analog-to-digital conversion. As a result, the quantization noise does not increase while the same high dynamic range of logarithmic image sensor is preserved. Moreover, by combining the gamma correction with the analog-to-digital conversion, the silicon area and overall power consumption can be greatly reduced. The proposed gamma correction scheme is validated by the reported simulation results and the experimental results measured for our designed test structure, which is fabricated with 0.35 μm standard complementary-metal-oxide-semiconductor (CMOS) process. PMID:25517692

  2. An analog gamma correction scheme for high dynamic range CMOS logarithmic image sensors.

    PubMed

    Cao, Yuan; Pan, Xiaofang; Zhao, Xiaojin; Wu, Huisi

    2014-01-01

    In this paper, a novel analog gamma correction scheme with a logarithmic image sensor dedicated to minimize the quantization noise of the high dynamic applications is presented. The proposed implementation exploits a non-linear voltage-controlled-oscillator (VCO) based analog-to-digital converter (ADC) to perform the gamma correction during the analog-to-digital conversion. As a result, the quantization noise does not increase while the same high dynamic range of logarithmic image sensor is preserved. Moreover, by combining the gamma correction with the analog-to-digital conversion, the silicon area and overall power consumption can be greatly reduced. The proposed gamma correction scheme is validated by the reported simulation results and the experimental results measured for our designed test structure, which is fabricated with 0.35 μm standard complementary-metal-oxide-semiconductor (CMOS) process. PMID:25517692

  3. Evaluation of High Dynamic Range Photography as a Luminance Mapping Technique

    SciTech Connect

    Inanici, Mehlika; Galvin, Jim

    2004-12-30

    The potential, limitations, and applicability of the High Dynamic Range (HDR) photography technique is evaluated as a luminance mapping tool. Multiple exposure photographs of static scenes are taken with a Nikon 5400 digital camera to capture the wide luminance variation within the scenes. The camera response function is computationally derived using the Photosphere software, and is used to fuse the multiple photographs into HDR images. The vignetting effect and point spread function of the camera and lens system is determined. Laboratory and field studies have shown that the pixel values in the HDR photographs can correspond to the physical quantity of luminance with reasonable precision and repeatability.

  4. The research on measurement technology of high dynamic range laser focal spot

    NASA Astrophysics Data System (ADS)

    Wang, Zhengzhou; Hu, Bingliang; Yin, Qinye; Cao, Shikang; Wang, Wei

    2015-10-01

    In order to obtain the far-field distribution of high dynamic range laser focal spot, the mathematical model of schlieren method to measure the far-field focal spot was proposed, and the traditional schlieren reconstructed algorithm was optimized in many aspects in this paper. First of all, the mathematical model which used to measure the far-field focal spot was created, the amplificatory coefficient K of the main lobe intensity and amplificatory coefficient b of the laser spot area were selected ; Secondly, the two important parameters were calibrated and the accurate main lobe spot and side lobe spot were captured by the integrated diagnostic beam fast automatic alignment system; Finally, the schlieren reconstructed algorithm was optimized by circle fitting method to calculate side lobe image center and weighted average method to fuse the joint image edge, and the error of traditional schlieren reconstruction method for side lobe center was reduced and the obvious joint mark of reconstructed image was eliminated completely. The method had been applied in a certain laser driver parameter measurement integrated diagnostic system to measure far-field laser focal spot. The experimental results show that the method can measure the far-field distribution of high dynamic range laser focal spot exactly on the condition that the parameter of mathematical model is calibrated accurately and the reconstructed algorithm of schlieren measure is optimized excellently.

  5. High dynamic range CMOS image sensor with pixel level ADC and in-situ image enhancement

    NASA Astrophysics Data System (ADS)

    Harton, Austin V.; Ahmed, Mohamed I.; Beuhler, Allyson; Castro, Francisco; Dawson, Linda M.; Herold, Barry W.; Kujawa, Gregory; Lee, King F.; Mareachen, Russell D.; Scaminaci, Tony J.

    2005-03-01

    We describe a CMOS image sensor with pixel level analog to digital conversion (ADC) having high dynamic range (>100db) and the capability of performing many image processing functions at the pixel level during image capture. The sensor has a 102x98 pixel array and is implemented in a 0.18um CMOS process technology. Each pixel is 15.5um x15.5um with 15% fill factor and is comprised of a comparator, two 10 bit memory registers and control logic. A digital to analog converter and system processor are located off-chip. The photodetector produces a photocurrent yielding a photo-voltage proportional to the impinging light intensity. Once the photo-voltage is less than a predetermined global reference voltage; a global code value is latched into the pixel data buffer. This process prevents voltage saturation resulting in high dynamic range imaging. Upon completion of image capture, a digital representation of the image exists at the pixel array, thereby, allowing image data to be accessed in a parallel fashion from the focal plane array. It is demonstrated that by appropriate variation of the global reference voltage with time, it is possible to perform, during image capture, thresholding and image enhancement operations, such as, contrast stretching in a parallel manner.

  6. A 4MP high-dynamic-range, low-noise CMOS image sensor

    NASA Astrophysics Data System (ADS)

    Ma, Cheng; Liu, Yang; Li, Jing; Zhou, Quan; Chang, Yuchun; Wang, Xinyang

    2015-03-01

    In this paper we present a 4 Megapixel high dynamic range, low dark noise and dark current CMOS image sensor, which is ideal for high-end scientific and surveillance applications. The pixel design is based on a 4-T PPD structure. During the readout of the pixel array, signals are first amplified, and then feed to a low- power column-parallel ADC array which is already presented in [1]. Measurement results show that the sensor achieves a dynamic range of 96dB, a dark noise of 1.47e- at 24fps speed. The dark current is 0.15e-/pixel/s at -20oC.

  7. High dynamic range infrared images detail enhancement based on local edge preserving filter

    NASA Astrophysics Data System (ADS)

    Song, Qiong; Wang, Yuehuan; Bai, Kun

    2016-07-01

    In the field of infrared (IR) image processing, displaying a high dynamic range (HDR) image on a low dynamic range display equipment with a natural visual effect, clear details on local areas and less artifacts is an important issue. In this paper, we present a new approach to display HDR IR images with contrast enhancement. First, the local edge-preserving filter (LEPF) is utilized to separate the image into a base layer and detail layer(s). After the filtering procedure, we use an adaptive Gamma transformation to adjust the gray distribution of the base layer, and stretch the detail layer based on a human visual effect principle. Then, we recombine the detail layer and base layer to obtain the enhance output. Finally, we adjust the luminance of output by applying multiple exposure fusion method. The experimental results demonstrate that our proposed method can provide a significant performance in terms of enhancing details and less artifacts than the state of the arts.

  8. Fast measurement of automotive headlamps based on high dynamic range imaging.

    PubMed

    Wu, Hsien-Huang P; Lee, Yi-Ping; Chang, Shih-Hsin

    2012-10-01

    The headlamp of the automobile is a very important device for the safety of driving in the dark. Therefore, the distribution of the light designed to provide forward and lateral illumination needs to meet the requirements of various regulations. Traditional measurement of the distribution has been based on a point-by-point approach using a goniophotometer. In this paper, an imaging photometer is developed by combining a regular digital camera and a high dynamic range imaging technique to achieve faster and more complete measurement of the entire distribution. The experimental results indicate that errors of the measurements are within 10% of the true values, which is better than the 20% requirements of the industry. PMID:23033105

  9. Endoscopic system for automated high dynamic range inspection of moving periodic structures

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius; Rothe, Hendrik

    2015-09-01

    In the current paper an advanced endoscopic system for high resolution and high dynamic range inspection of periodic structures in rotating machines is presented. We address the system architecture, short time illumination, special optical problems, such as excluding the specular reflex, image processing, forward velocity prediction and metrological image processing. There are several special requirements to be met, such as the thermal stability above 100°C, robustness of the image field, illumination in view direction and the separation of metallic surface diffuse scatter. To find a compromise between image resolution and frame rate, an external sensor system was applied for synchronization with the moving target. The system originally was intended for inspection of thermal engines, but turned out to be of a more general use. Beside the theoretical part and dimensioning issues, practical examples and measurement results are included.

  10. Adaptive digital fringe projection technique for high dynamic range three-dimensional shape measurement.

    PubMed

    Lin, Hui; Gao, Jian; Mei, Qing; He, Yunbo; Liu, Junxiu; Wang, Xingjin

    2016-04-01

    It is a challenge for any optical method to measure objects with a large range of reflectivity variation across the surface. Image saturation results in incorrect intensities in captured fringe pattern images, leading to phase and measurement errors. This paper presents a new adaptive digital fringe projection technique which avoids image saturation and has a high signal to noise ratio (SNR) in the three-dimensional (3-D) shape measurement of objects that has a large range of reflectivity variation across the surface. Compared to previous high dynamic range 3-D scan methods using many exposures and fringe pattern projections, which consumes a lot of time, the proposed technique uses only two preliminary steps of fringe pattern projection and image capture to generate the adapted fringe patterns, by adaptively adjusting the pixel-wise intensity of the projected fringe patterns based on the saturated pixels in the captured images of the surface being measured. For the bright regions due to high surface reflectivity and high illumination by the ambient light and surfaces interreflections, the projected intensity is reduced just to be low enough to avoid image saturation. Simultaneously, the maximum intensity of 255 is used for those dark regions with low surface reflectivity to maintain high SNR. Our experiments demonstrate that the proposed technique can achieve higher 3-D measurement accuracy across a surface with a large range of reflectivity variation. PMID:27137056

  11. The simulation of a readout integrated circuit with high dynamic range for long wave infrared FPA

    NASA Astrophysics Data System (ADS)

    Zhai, Yongcheng; Ding, Rui-jun; Chen, Guo-qiang; Wang, Pan; Hao, Li-chao

    2013-12-01

    This paper describes the simulation results of a high performance readout integrated circuit (ROIC) designed for long wave infrared (LWIR) detectors, which has high dynamic range (HDR). A special architecture is used to the input unit cell to accommodate the wide scene dynamic range requirement, thus providing over a factor of 70dB dynamic range. A capacitive feedback transimpedance amplifier (CTIA) provides a low noise detector interface circuit capable of operating at low input currents and a folded cascade amplifier with a gain of 73dB is designed. A 6.4pF integration capacitor is used for supporting a wide scene dynamic range, which can store 80Me. Because of the restriction of the layout area, four unit cells will share an integration capacitor. A sample and hold capacitor is also part of the input unit cell architecture, which allows the infrared focal plane arrays (IRFPA) to be operated in full frame snapshot mode and provides the maximum integration time available. The integration time is electronically controlled by an external clock pulse. The simulation results show that the circuit works well under 5V power supply and the nonlinearity is calculated less than 0.1%. The total power dissipation is less than 150mW.

  12. Computationally Efficient Truncated Nuclear Norm Minimization for High Dynamic Range Imaging.

    PubMed

    Lee, Chul; Lam, Edmund Y

    2016-09-01

    Matrix completion is a rank minimization problem to recover a low-rank data matrix from a small subset of its entries. Since the matrix rank is nonconvex and discrete, many existing approaches approximate the matrix rank as the nuclear norm. However, the truncated nuclear norm is known to be a better approximation to the matrix rank than the nuclear norm, exploiting a priori target rank information about the problem in rank minimization. In this paper, we propose a computationally efficient truncated nuclear norm minimization algorithm for matrix completion, which we call TNNM-ALM. We reformulate the original optimization problem by introducing slack variables and considering noise in the observation. The central contribution of this paper is to solve it efficiently via the augmented Lagrange multiplier (ALM) method, where the optimization variables are updated by closed-form solutions. We apply the proposed TNNM-ALM algorithm to ghost-free high dynamic range imaging by exploiting the low-rank structure of irradiance maps from low dynamic range images. Experimental results on both synthetic and real visual data show that the proposed algorithm achieves significantly lower reconstruction errors and superior robustness against noise than the conventional approaches, while providing substantial improvement in speed, thereby applicable to a wide range of imaging applications. PMID:27352392

  13. Design of a ROIC with high dynamic range for LWIR FPAs

    NASA Astrophysics Data System (ADS)

    Zhai, Yongcheng; Ding, Ruijun

    2014-11-01

    In this paper, a high performance readout integrated circuit (ROIC) designed for long wave infrared (LWIR) detectors is introduced, which has high dynamic range (HDR). To accommodate the wide scene dynamic range requirement, special circuit architecture is used to the input unit cell. A capacitive feedback transimpedance amplifier (CTIA) as input circuit is used to provide high injection efficiency, low input resistance, good linearity, precise voltage bias. Because of the restriction of the layout area, four unit cells will share an integration capacitor and each unit cell has a correlated double sampling (CDS) circuit, which allows the infrared focal plane arrays (IRFPA) to be operated in full frame snapshot mode and provides the maximum integration time available. The charge transfer circuit is used and we don't need to consider the drive ability of the unit cell. The simulation results confirm that the ROIC provides over a factor of 70dB dynamic range with the 5.0v power supply.

  14. Chroma sampling and modulation techniques in high dynamic range video coding

    NASA Astrophysics Data System (ADS)

    Dai, Wei; Krishnan, Madhu; Topiwala, Pankaj

    2015-09-01

    High Dynamic Range and Wide Color Gamut (HDR/WCG) Video Coding is an area of intense research interest in the engineering community, for potential near-term deployment in the marketplace. HDR greatly enhances the dynamic range of video content (up to 10,000 nits), as well as broadens the chroma representation (BT.2020). The resulting content offers new challenges in its coding and transmission. The Moving Picture Experts Group (MPEG) of the International Standards Organization (ISO) is currently exploring coding efficiency and/or the functionality enhancements of the recently developed HEVC video standard for HDR and WCG content. FastVDO has developed an advanced approach to coding HDR video, based on splitting the HDR signal into a smoothed luminance (SL) signal, and an associated base signal (B). Both signals are then chroma downsampled to YFbFr 4:2:0 signals, using advanced resampling filters, and coded using the Main10 High Efficiency Video Coding (HEVC) standard, which has been developed jointly by ISO/IEC MPEG and ITU-T WP3/16 (VCEG). Our proposal offers both efficient coding, and backwards compatibility with the existing HEVC Main10 Profile. That is, an existing Main10 decoder can produce a viewable standard dynamic range video, suitable for existing screens. Subjective tests show visible improvement over the anchors. Objective tests show a sizable gain of over 25% in PSNR (RGB domain) on average, for a key set of test clips selected by the ISO/MPEG committee.

  15. Inter-Layer Prediction of Color in High Dynamic Range Image Scalable Compression.

    PubMed

    Le Pendu, Mikael; Guillemot, Christine; Thoreau, Dominique

    2016-08-01

    This paper presents a color inter-layer prediction (ILP) method for scalable coding of high dynamic range (HDR) video content with a low dynamic range (LDR) base layer. Relying on the assumption of hue preservation between the colors of an HDR image and its LDR tone mapped version, we derived equations for predicting the chromatic components of the HDR layer given the decoded LDR layer. Two color representations are studied. In a first encoding scheme, the HDR image is represented in the classical Y'CbCr format. In addition, a second scheme is proposed using a colorspace based on the CIE u'v' uniform chromaticity scale diagram. In each case, different prediction equations are derived based on a color model ensuring the hue preservation. Our experiments highlight several advantages of using a CIE u'v'-based colorspace for the compression of HDR content, especially in a scalable context. In addition, our ILP scheme using this color representation improves on the state-of-the-art ILP method, which directly predicts the HDR layer u'v' components by computing the LDR layers u'v' values of each pixel. PMID:27244738

  16. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

    PubMed Central

    Giewekemeyer, Klaus; Philipp, Hugh T.; Wilke, Robin N.; Aquila, Andrew; Osterhoff, Markus; Tate, Mark W.; Shanks, Katherine S.; Zozulya, Alexey V.; Salditt, Tim; Gruner, Sol M.; Mancuso, Adrian P.

    2014-01-01

    Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 108 8-keV photons pixel−1 s−1, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 1010 photons µm−2 s−1 within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described. PMID:25178008

  17. High-dynamic-range texture compression for rendering systems of different capacities.

    PubMed

    Sun, Wen; Lu, Yan; Wu, Feng; Li, Shipeng; Tardif, John

    2010-01-01

    In this paper, we propose a novel approach for high-dynamic-range (HDR) texture compression (TC) suitable for rendering systems of different capacities. Based on the previously proposed DHTC scheme, we first work out an improved joint-channel compression framework, which is robust and flexible enough to provide compressed HDR textures at different bit rates. Then, two compressed HDR texture formats based on the proposed framework are developed. The 8 bpp format is of near lossless visual quality, improving upon known state-of-the-art algorithms. And, to our knowledge, the 4 bpp format is the first workable 4 bpp solution with good quality. We also show that HDR textures in the proposed 4 bpp and 8 bpp formats can compose a layered architecture in the texture consumption pipeline, to significantly save the memory bandwidth and storage in real-time rendering. In addition, the 8 bpp format can also be used to handle traditional low dynamic range (LDR) RGBA textures. Our scheme exhibits a practical solution for compressing HDR textures at different rates and LDR textures with alpha maps. PMID:19910661

  18. Context-dependent JPEG backward-compatible high-dynamic range image compression

    NASA Astrophysics Data System (ADS)

    Korshunov, Pavel; Ebrahimi, Touradj

    2013-10-01

    High-dynamic range (HDR) imaging is expected, together with ultrahigh definition and high-frame rate video, to become a technology that may change photo, TV, and film industries. Many cameras and displays capable of capturing and rendering both HDR images and video are already available in the market. The popularity and full-public adoption of HDR content is, however, hindered by the lack of standards in evaluation of quality, file formats, and compression, as well as large legacy base of low-dynamic range (LDR) displays that are unable to render HDR. To facilitate the wide spread of HDR usage, the backward compatibility of HDR with commonly used legacy technologies for storage, rendering, and compression of video and images are necessary. Although many tone-mapping algorithms are developed for generating viewable LDR content from HDR, there is no consensus of which algorithm to use and under which conditions. We, via a series of subjective evaluations, demonstrate the dependency of the perceptual quality of the tone-mapped LDR images on the context: environmental factors, display parameters, and image content itself. Based on the results of subjective tests, it proposes to extend JPEG file format, the most popular image format, in a backward compatible manner to deal with HDR images also. An architecture to achieve such backward compatibility with JPEG is proposed. A simple implementation of lossy compression demonstrates the efficiency of the proposed architecture compared with the state-of-the-art HDR image compression.

  19. Nonlinear mapping of the luminance in dual-layer high dynamic range displays

    NASA Astrophysics Data System (ADS)

    Guarnieri, Gabriele; Ramponi, Giovanni; Bonfiglio, Silvio; Albani, Luigi

    2009-02-01

    It has long been known that the human visual system (HVS) has a nonlinear response to luminance. This nonlinearity can be quantified using the concept of just noticeable difference (JND), which represents the minimum amplitude of a specified test pattern an average observer can discern from a uniform background. The JND depends on the background luminance following a threshold versus intensity (TVI) function. It is possible to define a curve which maps physical luminances into a perceptually linearized domain. This mapping can be used to optimize a digital encoding, by minimizing the visibility of quantization noise. It is also commonly used in medical applications to display images adapting to the characteristics of the display device. High dynamic range (HDR) displays, which are beginning to appear on the market, can display luminance levels outside the range in which most standard mapping curves are defined. In particular, dual-layer LCD displays are able to extend the gamut of luminance offered by conventional liquid crystals towards the black region; in such areas suitable and HVS-compliant luminance transformations need to be determined. In this paper we propose a method, which is primarily targeted to the extension of the DICOM curve used in medical imaging, but also has a more general application. The method can be modified in order to compensate for the ambient light, which can be significantly greater than the black level of an HDR display and consequently reduce the visibility of the details in dark areas.

  20. High dynamic range pixel architecture for advanced diagnostic medical x-ray imaging applications

    SciTech Connect

    Izadi, Mohammad Hadi; Karim, Karim S.

    2006-05-15

    The most widely used architecture in large-area amorphous silicon (a-Si) flat panel imagers is a passive pixel sensor (PPS), which consists of a detector and a readout switch. While the PPS has the advantage of being compact and amenable toward high-resolution imaging, small PPS output signals are swamped by external column charge amplifier and data line thermal noise, which reduce the minimum readable sensor input signal. In contrast to PPS circuits, on-pixel amplifiers in a-Si technology reduce readout noise to levels that can meet even the stringent requirements for low noise digital x-ray fluoroscopy (<1000 noise electrons). However, larger voltages at the pixel input cause the output of the amplified pixel to become nonlinear thus reducing the dynamic range. We reported a hybrid amplified pixel architecture based on a combination of PPS and amplified pixel designs that, in addition to low noise performance, also resulted in large-signal linearity and consequently higher dynamic range [K. S. Karim et al., Proc. SPIE 5368, 657 (2004)]. The additional benefit in large-signal linearity, however, came at the cost of an additional pixel transistor. We present an amplified pixel design that achieves the goals of low noise performance and large-signal linearity without the need for an additional pixel transistor. Theoretical calculations and simulation results for noise indicate the applicability of the amplified a-Si pixel architecture for high dynamic range, medical x-ray imaging applications that require switching between low exposure, real-time fluoroscopy and high-exposure radiography.

  1. Unattended real-time re-establishment of visibility in high dynamic range video and stills

    NASA Astrophysics Data System (ADS)

    Abidi, B.

    2014-05-01

    We describe a portable unattended persistent surveillance system that corrects for harsh illumination conditions, where bright sun light creates mixed contrast effects, i.e., heavy shadows and washouts. These effects result in high dynamic range scenes, where illuminance can vary from few luxes to a 6 figure value. When using regular monitors and cameras, such wide span of illuminations can only be visualized if the actual range of values is compressed, leading to the creation of saturated and/or dark noisy areas and a loss of information in these areas. Images containing extreme mixed contrast cannot be fully enhanced from a single exposure, simply because all information is not present in the original data. The active intervention in the acquisition process is required. A software package, capable of integrating multiple types of COTS and custom cameras, ranging from Unmanned Aerial Systems (UAS) data links to digital single-lens reflex cameras (DSLR), is described. Hardware and software are integrated via a novel smart data acquisition algorithm, which communicates to the camera the parameters that would maximize information content in the final processed scene. A fusion mechanism is then applied to the smartly acquired data, resulting in an enhanced scene where information in both dark and bright areas is revealed. Multi-threading and parallel processing are exploited to produce automatic real time full motion corrected video. A novel enhancement algorithm was also devised to process data from legacy and non-controllable cameras. The software accepts and processes pre-recorded sequences and stills, enhances visible, night vision, and Infrared data, and successfully applies to night time and dark scenes. Various user options are available, integrating custom functionalities of the application into intuitive and easy to use graphical interfaces. The ensuing increase in visibility in surveillance video and intelligence imagery will expand the performance and

  2. Bayer patterned high dynamic range image reconstruction using adaptive weighting function

    NASA Astrophysics Data System (ADS)

    Kang, Hee; Lee, Suk Ho; Song, Ki Sun; Kang, Moon Gi

    2014-12-01

    It is not easy to acquire a desired high dynamic range (HDR) image directly from a camera due to the limited dynamic range of most image sensors. Therefore, generally, a post-process called HDR image reconstruction is used, which reconstructs an HDR image from a set of differently exposed images to overcome the limited dynamic range. However, conventional HDR image reconstruction methods suffer from noise factors and ghost artifacts. This is due to the fact that the input images taken with a short exposure time contain much noise in the dark regions, which contributes to increased noise in the corresponding dark regions of the reconstructed HDR image. Furthermore, since input images are acquired at different times, the images contain different motion information, which results in ghost artifacts. In this paper, we propose an HDR image reconstruction method which reduces the impact of the noise factors and prevents ghost artifacts. To reduce the influence of the noise factors, the weighting function, which determines the contribution of a certain input image to the reconstructed HDR image, is designed to adapt to the exposure time and local motions. Furthermore, the weighting function is designed to exclude ghosting regions by considering the differences of the luminance and the chrominance values between several input images. Unlike conventional methods, which generally work on a color image processed by the image processing module (IPM), the proposed method works directly on the Bayer raw image. This allows for a linear camera response function and also improves the efficiency in hardware implementation. Experimental results show that the proposed method can reconstruct high-quality Bayer patterned HDR images while being robust against ghost artifacts and noise factors.

  3. High Dynamic Range Image rendering of color in chameleons' camouflage using optical thin films

    NASA Astrophysics Data System (ADS)

    Prusten, Mark

    2008-08-01

    High Dynamic Range Image (HDRI) rendering and animation of color in the camouflage of chameleons is developed utilizing thin film optics. Chameleons are a lizard species, and have the ability to change their skin color. This change in color is an expression of the physical and physiological conditions of the lizard, and plays a part in communication. The different colors that can be produced depending on the species include pink, blue, red, orange, green, black, brown and yellow. The modeling, simulation, and rendering of the color, which their skin incorporates, thin film optical stacks. The skin of a chameleon has four layers, which together produce various colors. The outside transparent layer has chromatophores cells, of two kinds of color, yellow and red. Next there are two more layers that reflect light: one blue and the other white. The innermost layer contains dark pigment granules or melanophore cells that influences the amount of reflected light. All of these pigment cells can rapidly relocate their pigments, thereby influencing the color of the chameleon. Techniques like subsurface scattering, the simulation of volumetric scattering of light underneath the objects surface, and final gathering are defined in custom shaders and material phenomena for the renderer. The workflow developed to model the chameleon's skin is also applied to simulation and rendering of hair and fur camouflage, which does not exist in nature.

  4. Towards high dynamic range extensions of HEVC: subjective evaluation of potential coding technologies

    NASA Astrophysics Data System (ADS)

    Hanhart, Philippe; Řeřábek, Martin; Ebrahimi, Touradj

    2015-09-01

    This paper reports the details and results of the subjective evaluations conducted at EPFL to evaluate the responses to the Call for Evidence (CfE) for High Dynamic Range (HDR) and Wide Color Gamut (WCG) Video Coding issued by Moving Picture Experts Group (MPEG). The CfE on HDR/WCG Video Coding aims to explore whether the coding efficiency and/or the functionality of the current version of HEVC standard can be signi_cantly improved for HDR and WCG content. In total, nine submissions, five for Category 1 and four for Category 3a, were compared to the HEVC Main 10 Profile based Anchor. More particularly, five HDR video contents, compressed at four bit rates by each proponent responding to the CfE, were used in the subjective evaluations. Further, the side-by-side presentation methodology was used for the subjective experiment to discriminate small differences between the Anchor and proponents. Subjective results shows that the proposals provide evidence that the coding efficiency can be improved in a statistically noticeable way over MPEG CfE Anchors in terms of perceived quality within the investigated content. The paper further benchmarks the selected objective metrics based on their correlations with the subjective ratings. It is shown that PSNR-DE1000, HDRVDP- 2, and PSNR-Lx can reliably detect visible differences between the proposed encoding solutions and current HEVC standard.

  5. Hardware-based smart camera for recovering high dynamic range video from multiple exposures

    NASA Astrophysics Data System (ADS)

    Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

    2014-10-01

    In many applications such as video surveillance or defect detection, the perception of information related to a scene is limited in areas with strong contrasts. The high dynamic range (HDR) capture technique can deal with these limitations. The proposed method has the advantage of automatically selecting multiple exposure times to make outputs more visible than fixed exposure ones. A real-time hardware implementation of the HDR technique that shows more details both in dark and bright areas of a scene is an important line of research. For this purpose, we built a dedicated smart camera that performs both capturing and HDR video processing from three exposures. What is new in our work is shown through the following points: HDR video capture through multiple exposure control, HDR memory management, HDR frame generation, and representation under a hardware context. Our camera achieves a real-time HDR video output at 60 fps at 1.3 megapixels and demonstrates the efficiency of our technique through an experimental result. Applications of this HDR smart camera include the movie industry, the mass-consumer market, military, automotive industry, and surveillance.

  6. Characterization method for a multispectral high-dynamic-range imaging system

    NASA Astrophysics Data System (ADS)

    Kim, Duck Bong; Lee, Kwan H.

    2014-07-01

    An accurate characterization method for a multispectral high-dynamic-range (HDR) imaging system is proposed by combining multispectral and HDR imaging technologies. The multispectral HDR imaging system, which can acquire the visible spectrum at many wavelength bands, can provide an accurate color reproduction and physical radiance information of real objects. An HDR camera is used to capture an HDR image without multiple exposures and a liquid crystal tunable filter (LCTF) is used to generate multispectral images. Due to its several limitations in the multispectral HDR imaging system, a carefully designed and an innovative characterization algorithm is presented by considering a logarithmic camera response of the HDR camera and different spectral transmittance of the LCTF. The proposed method efficiently and accurately recovers the full spectrum from the multispectral HDR images using a transformation matrix and provides device-independent color information (e.g., CIEXYZ and CIELAB). The transformation matrix is estimated by training the estimated sensor responses from a multispectral HDR imaging system and the reflectance measurements from a spectroradiometer using Moore-Penrose pseudoinverse matrix.

  7. Signal enhancement in optical projection tomography via virtual high dynamic range imaging of single exposure

    NASA Astrophysics Data System (ADS)

    Yang, Yujie; Dong, Di; Shi, Liangliang; Wang, Jun; Yang, Xin; Tian, Jie

    2015-03-01

    Optical projection tomography (OPT) is a mesoscopic scale optical imaging technique for specimens between 1mm and 10mm. OPT has been proven to be immensely useful in a wide variety of biological applications, such as developmental biology and pathology, but its shortcomings in imaging specimens containing widely differing contrast elements are obvious. The longer exposure for high intensity tissues may lead to over saturation of other areas, whereas a relatively short exposure may cause similarity with surrounding background. In this paper, we propose an approach to make a trade-off between capturing weak signals and revealing more details for OPT imaging. This approach consists of three steps. Firstly, the specimens are merely scanned in 360 degrees above a normal exposure but non-overexposure to acquire the projection data. This reduces the photo bleaching and pre-registration computation compared with multiple different exposures in conventional high dynamic range (HDR) imaging method. Secondly, three virtual channels are produced for each projection image based on the histogram distribution to simulate the low, normal and high exposure images used in the traditional HDR technology in photography. Finally, each virtual channel is normalized to the full gray scale range and three channels are recombined into one image using weighting coefficients optimized by a standard eigen-decomposition method. After applying our approach on the projection data, filtered back projection (FBP) algorithm is carried out for 3-dimentional reconstruction. The neonatal wild-type mouse paw has been scanned to verify this approach. Results demonstrated the effectiveness of the proposed approach.

  8. High dynamic range CMOS-based mammography detector for FFDM and DBT

    NASA Astrophysics Data System (ADS)

    Peters, Inge M.; Smit, Chiel; Miller, James J.; Lomako, Andrey

    2016-03-01

    Digital Breast Tomosynthesis (DBT) requires excellent image quality in a dynamic mode at very low dose levels while Full Field Digital Mammography (FFDM) is a static imaging modality that requires high saturation dose levels. These opposing requirements can only be met by a dynamic detector with a high dynamic range. This paper will discuss a wafer-scale CMOS-based mammography detector with 49.5 μm pixels and a CsI scintillator. Excellent image quality is obtained for FFDM as well as DBT applications, comparing favorably with a-Se detectors that dominate the X-ray mammography market today. The typical dynamic range of a mammography detector is not high enough to accommodate both the low noise and the high saturation dose requirements for DBT and FFDM applications, respectively. An approach based on gain switching does not provide the signal-to-noise benefits in the low-dose DBT conditions. The solution to this is to add frame summing functionality to the detector. In one X-ray pulse several image frames will be acquired and summed. The requirements to implement this into a detector are low noise levels, high frame rates and low lag performance, all of which are unique characteristics of CMOS detectors. Results are presented to prove that excellent image quality is achieved, using a single detector for both DBT as well as FFDM dose conditions. This method of frame summing gave the opportunity to optimize the detector noise and saturation level for DBT applications, to achieve high DQE level at low dose, without compromising the FFDM performance.

  9. High-resolution full-field optical coherence tomography using high dynamic range image processing

    NASA Astrophysics Data System (ADS)

    Leong-Hoï, A.; Claveau, R.; Montgomery, P. C.; Serio, B.; Uhring, W.; Anstotz, F.; Flury, M.

    2016-04-01

    Full-field optical coherence tomography (FF-OCT) based on white-light interference microscopy, is an emerging noninvasive imaging technique for characterizing biological tissue or optical scattering media with micrometer resolution. Tomographic images can be obtained by analyzing a sequence of interferograms acquired with a camera. This is achieved by scanning an interferometric microscope objectives along the optical axis and performing appropriate signal processing for fringe envelope extraction, leading to three-dimensional imaging over depth. However, noise contained in the images can hide some important details or induce errors in the size of these details. To firstly reduce temporal and spatial noise from the camera, it is possible to apply basic image post processing methods such as image averaging, dark frame subtraction or flat field division. It has been demonstrate that this can improve the quality of microscopy images by enhancing the signal to noise ratio. In addition, the dynamic range of images can be enhanced to improve the contrast by combining images acquired with different exposure times or light intensity. This can be made possible by applying a hybrid high dynamic range (HDR) technique, which is proposed in this paper. High resolution tomographic analysis is thus performed using a combination of the above-mentioned image processing techniques. As a result, the lateral resolution of the system can be improved so as to approach the diffraction limit of the microscope as well as to increase the power of detection, thus enabling new sub-diffraction sized structures contained in a transparent layer, initially hidden by the noise, to be detected.

  10. A high dynamic range power sensor based on GaAs MMIC process and MEMS technology

    NASA Astrophysics Data System (ADS)

    Yi, Zhenxiang; Liao, Xiaoping

    2016-01-01

    This paper reports a high dynamic range power sensor based on GaAs process and MEMS technology. The proposed sensor consisted of the terminating-type sensor and the coupling-type sensor. The former measures low power while the latter is for high power detection. This device is designed and fabricated by GaAs MMIC process. In order to optimize microwave performance, impedance compensating technology by increasing the slot width of the CPW transmission line is developed. Related calculation and simulation are also presented in this paper. The microwave performance test reveals that the return loss is close to -28 dB@8 GHz, -27 dB@10 GHz and -26 dB@12 GHz, respectively. The microwave power response experiment is investigated from 1 mW to 150 mW. For the incident power less than 100 mW, the terminating-type sensor operates and the measured sensitivity is about 0.095 mV/mW@8 GHz, 0.088 mV/mW@10 GHz and 0.084 mV/mW@12 GHz, respectively. Related lumped equivalent circuit models of the loaded resistors are developed to explain the loss induced by the frequency of the signal. For the incident power with the improved dynamic range from 100 mW to 150 mW, the coupling-type sensor is adopted and the measured sensitivity is about 9.2 μV/mW@8 GHz, 8.6 μV/mW@8 GHz and 9.0 μV/mW@12 GHz, respectively.

  11. Adaptive exposure estimation for high dynamic range imaging applied to natural scenes and daylight skies.

    PubMed

    Martínez, Miguel A; Valero, Eva M; Hernández-Andrés, Javier

    2015-02-01

    Digital imaging of natural scenes and optical phenomena present on them (such as shadows, twilights, and crepuscular rays) can be a very challenging task because of the range spanned by the radiances impinging on the capture system. We propose a novel method for estimating the set of exposure times (bracketing set) needed to capture the full dynamic range of a scene with high dynamic range (HDR) content. The proposed method is adaptive to scene content and to any camera response and configuration, and it works on-line since the exposure times are estimated as the capturing process is ongoing. Besides, it requires no a priori information about scene content or radiance values. The resulting bracketing sets are minimal in the default method settings, but the user can set a tolerance for the maximum percentage of pixel population that is underexposed or saturated, which allows for a higher number of shots if a better signal-to-noise ratio (SNR) in the HDR scene is desired. This method is based on the use of the camera response function that is needed for building the HDR radiance map by stitching together several differently exposed low dynamic range images of the scene. The use of HDR imaging techniques converts our digital camera into a tool for measuring the relative radiance outgoing from each point of the scene, and for each color channel. This is important for accurate characterization of optical phenomena present in the atmosphere while not suffering any loss of information due to its HDR. We have compared our method with the most similar one developed so far [IEEE Trans. Image Process.17, 1864 (2008)]. Results of the experiments carried out for 30 natural scenes show that our proposed method equals or outperforms the previously developed best approach, with less shots and shorter exposure times, thereby asserting the advantage of being adaptive to scene content for exposure time estimation. As we can also tune the balance between capturing time and the SNR in

  12. Do High Dynamic Range threatments improve the results of Structure from Motion approaches in Geomorphology?

    NASA Astrophysics Data System (ADS)

    Gómez-Gutiérrez, Álvaro; Juan de Sanjosé-Blasco, José; Schnabel, Susanne; de Matías-Bejarano, Javier; Pulido-Fernández, Manuel; Berenguer-Sempere, Fernando

    2015-04-01

    In this work, the hypothesis of improving 3D models obtained with Structure from Motion (SfM) approaches using images pre-processed by High Dynamic Range (HDR) techniques is tested. Photographs of the Veleta Rock Glacier in Spain were captured with different exposure values (EV0, EV+1 and EV-1), two focal lengths (35 and 100 mm) and under different weather conditions for the years 2008, 2009, 2011, 2012 and 2014. HDR images were produced using the different EV steps within Fusion F.1 software. Point clouds were generated using commercial and free available SfM software: Agisoft Photoscan and 123D Catch. Models Obtained using pre-processed images and non-preprocessed images were compared in a 3D environment with a benchmark 3D model obtained by means of a Terrestrial Laser Scanner (TLS). A total of 40 point clouds were produced, georeferenced and compared. Results indicated that for Agisoft Photoscan software differences in the accuracy between models obtained with pre-processed and non-preprocessed images were not significant from a statistical viewpoint. However, in the case of the free available software 123D Catch, models obtained using images pre-processed by HDR techniques presented a higher point density and were more accurate. This tendency was observed along the 5 studied years and under different capture conditions. More work should be done in the near future to corroborate whether the results of similar software packages can be improved by HDR techniques (e.g. ARC3D, Bundler and PMVS2, CMP SfM, Photosynth and VisualSFM).

  13. Front end ASIC for AGIPD, a high dynamic range fast detector for the European XFEL

    NASA Astrophysics Data System (ADS)

    Allahgholi, A.; Becker, J.; Bianco, L.; Delfs, A.; Dinapoli, R.; Ariño-Estrada, G.; Goettlicher, P.; Graafsma, H.; Greiffenberg, D.; Hirsemann, H.; Jack, S.; Klanner, R.; Klyuev, A.; Krueger, H.; Lange, S.; Marras, A.; Mezza, D.; Mozzanica, A.; Poehlsen, J.; Rah, S.; Xia, Q.; Schmitt, B.; Schwandt, J.; Sheviakov, I.; Shi, X.; Smoljanin, S.; Trunk, U.; Zhang, J.; Zimmer, M.

    2016-01-01

    The Adaptive Gain Integrating Pixel Detector (AGIPD) is a hybrid pixel X-ray detector for the European-XFEL. One of the detector's important parts is the radiation tolerant front end ASIC fulfilling the European-XFEL requirements: high dynamic range—from sensitivity to single 12.5keV-photons up to 104 photons. It is implemented using the dynamic gain switching technique with three possible gains of the charge sensitive preamplifier. Each pixel can store up to 352 images in memory operated in random-access mode at >=4.5 MHz frame rate. An external vetoing may be applied to overwrite unwanted frames.

  14. High dynamic range image acquisition method for 3D solder paste measurement

    NASA Astrophysics Data System (ADS)

    Li, Xiaohui; Sun, Changku; Wang, Peng; Xu, Yixin

    2013-12-01

    In the solder paste inspection measurement system which is based on the structured light vision technology, the local oversaturation will emerge because of the reflection coefficient when the laser light project on PCB surface. As this, a high dynamic imaging acquisition system for the solder paste inspection research is researched to reduce the local oversaturation and misjudge. The Reflective liquid crystal on silicon has the merit that it can adjust the reflectance of the Incident light per-pixel. According to this merit, the high dynamic imaging acquisition system based on liquid crystal on silicon (LCoS) was built which using the high-resolution LCoS and CCD image sensor. The optical system was constructed by the imaging lens, the relay lens, the Polarizing Beam Splitter (PBS), and the hardware system was consist of ARM development board, video generic board, MCU and HX7809 according to the electrical characteristics of LCoS. Tests show that the system could reduce the phenomenon of image oversaturation and improve the quality of image.

  15. High dynamic range measurement of the pulse contrast in a Ti:sapphire/Nd:glass multiterawatt laser

    NASA Astrophysics Data System (ADS)

    Castanheira, Ana; Cardoso, Luís; Pires, Hugo; Figueira, Gonçalo

    2011-05-01

    We describe the design and implementation study of a high dynamic range, third order contrast-ratio measurement diagnostic for a high power laser chain. The device, known as Optical Parametric Amplification Correlator (OPAC) is based on degenerate three-wave mixing in a nonlinear crystal, it is self-referencing and compact. By measuring the idler pulse with a slow detector and a set of calibrated filters, a dynamic range of up to 1010 is achievable. The pulse contrast is to be characterized at the mJ-level, 10 Hz, Ti:sapphire pre-amplifier stage, in a time window of 100 ps.

  16. High Dynamic Velocity Range Particle Image Velocimetry Using Multiple Pulse Separation Imaging

    PubMed Central

    Persoons, Tim; O’Donovan, Tadhg S.

    2011-01-01

    The dynamic velocity range of particle image velocimetry (PIV) is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets) still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by over an order of magnitude. The multiple pulse separation (MPS) technique (i) records series of double-frame exposures with different pulse separations, (ii) processes the fields using conventional multi-grid algorithms, and (iii) yields a composite velocity field with a locally optimized pulse separation. A robust criterion determines the local optimum pulse separation, accounting for correlation strength and measurement uncertainty. Validation experiments are performed in an impinging jet flow, using laser-Doppler velocimetry as reference measurement. The precision of mean flow and turbulence quantities is significantly improved compared to conventional PIV, due to the increase in dynamic range. In a wide range of applications, MPS PIV is a robust approach to increase the dynamic velocity range without restricting the vector evaluation methods. PMID:22346564

  17. Generalised optical differentiation wavefront sensor: a sensitive high dynamic range wavefront sensor.

    PubMed

    Haffert, S Y

    2016-08-22

    Current wavefront sensors for high resolution imaging have either a large dynamic range or a high sensitivity. A new kind of wavefront sensor is developed which can have both: the Generalised Optical Differentiation wavefront sensor. This new wavefront sensor is based on the principles of optical differentiation by amplitude filters. We have extended the theory behind linear optical differentiation and generalised it to nonlinear filters. We used numerical simulations and laboratory experiments to investigate the properties of the generalised wavefront sensor. With this we created a new filter that can decouple the dynamic range from the sensitivity. These properties make it suitable for adaptive optic systems where a large range of phase aberrations have to be measured with high precision. PMID:27557179

  18. High-Dynamic-Range Single-Shot Cross-Correlator Based on an Optical Pulse Replicator

    SciTech Connect

    Dorrer, C.; Bromage, J.; Zuegel, J.D.

    2008-09-05

    The operation of a single-shot cross-correlator based on a pulse replicator is described. The correlator uses a discrete sequence of sampling pulses that are nonlinearly mixed with the pulse under test. The combination of a high reflector and partial reflector replicates an optical pulse by multiple internal reflections and generates a sequence of spatially displaced and temporally delayed sampling pulses. This principle is used in a cross-correlator characterizing optical pulses at 1053 nm. A dynamic range higher than 60 dB is obtained over a temporal range larger than 200 ps.

  19. Method and apparatus of high dynamic range image sensor with individual pixel reset

    NASA Technical Reports Server (NTRS)

    Yadid-Pecht, Orly (Inventor); Pain, Bedabrata (Inventor); Fossum, Eric R. (Inventor)

    2001-01-01

    A wide dynamic range image sensor provides individual pixel reset to vary the integration time of individual pixels. The integration time of each pixel is controlled by column and row reset control signals which activate a logical reset transistor only when both signals coincide for a given pixel.

  20. Two-phase low-power analogue CMOS peak detector with high dynamic range

    NASA Astrophysics Data System (ADS)

    Malankin, E.

    2016-02-01

    A low-power two-phase peak detector with wide dynamic range was developed. The PD was designed on the basis ofthe CMOS UMC 180 nm process. This block is considered as a part of the read-out electronics of the CBM experiment at upcoming FAIR accelerator (Germany). Peak detector has the following advantages: wide dynamic range of 5 - 1000 mV, low power consumption of 500 µW. The designed PD meets the requirements to the muon chamber read-out electronics of the CBM experiment. Due to the area efficiency (100×90 μm2) and low power consumption it can be used in different applications for high-energy physics read-out electronics.

  1. A and B Ring Wakes in High Dynamic Range Radio Maps of Saturn

    NASA Astrophysics Data System (ADS)

    Molnar, L. A.; Crull, E. M.; Dunn, D. E.

    2004-11-01

    We have made new total intensity and polarized images at 3.6 cm wavelength of Saturn near maximum ring tilt (26.3 degrees). These Very Large Array maps have higher dynamic range than previous ones, and reveal a variety of new features. The total intensity of the A ring can be traced accurately over the full range of azimuth and shows clearly the features predicted by Dunn et al. (2004, Icarus, 171, 183) in wake simulations: strong east-west asymmetry on the far side of the rings, but not on the near. To our surprise, the inner portion of the B ring shows the same asymmetry signature, although with reduced amplitude. Furthermore, the same portion of the B ring shows asymmetry as it passes in front of the planet, a signature of wakes we have previously found in the A ring. (This was not seen in previous images, for which the B ring was too foreshortened to allow any direct transmission.) Taken together, this is the first evidence of wakes in this portion of the rings. This is not inconsistent with dynamical simulations, however, which show less organized but recognizable wakes at this radius. We will discuss quantitative implications for wake parameters in both rings based on modeling of the data with our simrings radiative transfer code. The polarized intensity map allows us to trace the strength and orientation of the polarized light over the full range of ring azimuths as well. The result is qualitatively consistent with polarization produced perpendicular to the source-ring-observer plane, with greatest strength at 90 degree scattering angle. In particular, the pattern of observed polarization position angle is consistent with light dominated by single scattering of light from the southern hemisphere (diffusely reflected light). This work was supported in part by a grant from Research Corporation.

  2. Adaptive uniform grayscale coded aperture design for high dynamic range compressive spectral imaging

    NASA Astrophysics Data System (ADS)

    Diaz, Nelson; Rueda, Hoover; Arguello, Henry

    2016-05-01

    Imaging spectroscopy is an important area with many applications in surveillance, agriculture and medicine. The disadvantage of conventional spectroscopy techniques is that they collect the whole datacube. In contrast, compressive spectral imaging systems capture snapshot compressive projections, which are the input of reconstruction algorithms to yield the underlying datacube. Common compressive spectral imagers use coded apertures to perform the coded projections. The coded apertures are the key elements in these imagers since they define the sensing matrix of the system. The proper design of the coded aperture entries leads to a good quality in the reconstruction. In addition, the compressive measurements are prone to saturation due to the limited dynamic range of the sensor, hence the design of coded apertures must consider saturation. The saturation errors in compressive measurements are unbounded and compressive sensing recovery algorithms only provide solutions for bounded noise or bounded with high probability. In this paper it is proposed the design of uniform adaptive grayscale coded apertures (UAGCA) to improve the dynamic range of the estimated spectral images by reducing the saturation levels. The saturation is attenuated between snapshots using an adaptive filter which updates the entries of the grayscale coded aperture based on the previous snapshots. The coded apertures are optimized in terms of transmittance and number of grayscale levels. The advantage of the proposed method is the efficient use of the dynamic range of the image sensor. Extensive simulations show improvements in the image reconstruction of the proposed method compared with grayscale coded apertures (UGCA) and adaptive block-unblock coded apertures (ABCA) in up to 10 dB.

  3. A high dynamic range current dosimeter for space ionization radiation measurement

    NASA Astrophysics Data System (ADS)

    Lei, Sheng-jie; Wei, Zhi-yong; Fang, Mei-hua; Chen, Guo-yun; Zhang, Zi-xia; Huang, San-bo

    2011-08-01

    A dosimeter for space ionization radiation field is developed, energy deposited in the sensitivity volume of ionization chamber induces an output current signal as weak as 10-14A, and the dynamic range of the signal is very high. Now, an ionization chamber is designed and a variable gain current feedback preamp module is designed for the weak output current amplification is connected to output of the ionization chamber anode. The amplifier module includes I-V converter with T shaped resistance net, zero correct circuit, low pass filter, voltage linear amplifier circuit, gain control circuit and voltage output circuit. A complete analysis of this current preamp with respect to its circuit structure, dynamic properties, its equivalent input noise and the temperature effect is given. The effects of stray impedances on the behavior of the current feedback preamp are taken into account and the techniques necessary to achieve an optimum stable electrometer, with respect to noise, Dc drift, leakage currents, are applied. Experiments show that the energy of dosimeter deposited in the sensitivity volume of ionization chamber induces an output current signal as weak as 10-14A, the current preamp can detect weak current effectively with the range from 100fA to 10μA through switchable gain.

  4. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy.

    PubMed

    Muir, Ryan D; Sullivan, Shane Z; Oglesbee, Robert A; Simpson, Garth J

    2014-03-01

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content. PMID:24689588

  5. Clock signal requirement for high-frequency, high dynamic range acquisition systems

    SciTech Connect

    Viscor, Ivo; Halamek, Josef; Villa, Marco

    2005-11-15

    Analog-to-digital converters (ADC's) are increasingly replacing mixers in frequency conversion schemes. To achieve superior performances, in terms of bandwidth and dynamic range, a nearly ideal ADC clock is needed, with a spectral purity higher than the reference signal of the classical mixing scheme. These requirements of spectral purity for the ADC clock are discussed by analyzing in detail the nonuniform sampling process and by characterizing an actual acquisition system. The effect of clock phase imperfections on the output is proportional to the input frequency over sampling frequency ratio. Moreover, at the output we may have a multiple folding of the phase jitter spectrum. These effects are illustrated by three sets of measurements performed using our system: transfer of spurious clock components, aliasing of these components, and transfer of clock phase noise.

  6. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy

    SciTech Connect

    Muir, Ryan D.; Sullivan, Shane Z.; Oglesbee, Robert A.; Simpson, Garth J.

    2014-03-15

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content.

  7. High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

    NASA Astrophysics Data System (ADS)

    Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

    2015-04-01

    Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

  8. Novel image detail enhancement technology for high dynamic range infrared detector

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Zhu, Caigao

    2014-11-01

    In this paper, we propose a novel image detail enhancement technology which is well solved the problem of how to suppress the noise and enhance the detail at the same time of the infrared image. This technology is based on the layer separation idea. In nowadays, this idea is studied by many researchers, and many detail enhancement algorithms have been come up through this idea such as the bilateral filter for detail enhancement. According to our research, these algorithms although have the advantages of enhancing the detail without enhancing the noise, they also have the disadvantages of massive calculation, low speed and the worst is the gradient flipping effect which cause the enhanced image distorted. Our solution is based on the Guided Image Filter (GIF) to deal the separated detail layer of an image. The gradient flipping effect will be greatly suppressed with the priority that the GIF is a linear filter. Which means that the processed image will become much closer to the original image. We determine an adaptive weighting coefficient as the filter kernel. After that, we compress the base component into the display range by our modified histogram projection and enhance the detail component using the gain mask of the filter weighting coefficient. At last, we recombine the two parts and quantize the result to 8-bit domain. Experimental verification and detailed realization have been provided in this paper. We also have done significant comparison between our method and the proposed algorithm to show the superiority of our algorithm.

  9. High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy.

    PubMed

    Tate, Mark W; Purohit, Prafull; Chamberlain, Darol; Nguyen, Kayla X; Hovden, Robert; Chang, Celesta S; Deb, Pratiti; Turgut, Emrah; Heron, John T; Schlom, Darrell G; Ralph, Daniel C; Fuchs, Gregory D; Shanks, Katherine S; Philipp, Hugh T; Muller, David A; Gruner, Sol M

    2016-02-01

    We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80-200 keV electron beams. PMID:26750260

  10. High-dynamic-range 4-Mpixel CMOS image sensor for scientific applications

    NASA Astrophysics Data System (ADS)

    Vu, Paul; Fowler, Boyd; Liu, Chiao; Mims, Steve; Bartkovjak, Peter; Do, Hung; Li, Wang; Appelbaum, Jeff; Lopez, Angel

    2012-03-01

    As bio-technology transitions from research and development to high volume production, dramatic improvements in image sensor performance will be required to support the throughput and cost requirements of this market. This includes higher resolution, higher frame rates, higher quantum efficiencies, increased system integration, lower read-noise, and lower device costs. We present the performance of a recently developed low noise 2048(H) x 2048(V) CMOS image sensor optimized for scientific applications such as life science imaging, microscopy, as well as industrial inspection applications. The sensor architecture consists of two identical halves which can be operated independently and the imaging array consists of 4T pixels with pinned photodiodes on a 6.5μm pitch with integrated micro-lens. The operation of the sensor is programmable through a SPI interface. The measured peak quantum efficiency of the sensor is 73% at 600nm, and the read noise is about 1.1e- RMS at 100 fps data rate. The sensor features dual gain column parallel ouput amplifiers with 11-bit single slope ADCs. The full well capacity is greater than 36ke-, the dark current is less than 7pA/cm2 at 20°C. The sensor achieves an intra-scene linear dynamic range of greater than 91dB (36000:1) at room temperature.

  11. A novel all-elastomer MEMS tactile sensor for high dynamic range shear and normal force sensing

    NASA Astrophysics Data System (ADS)

    Charalambides, Alexi; Bergbreiter, Sarah

    2015-09-01

    A novel all-elastomer MEMS tactile sensor with high dynamic force range is presented in this work. Conductive elastomeric capacitors formed from electrodes of varying heights enable robust sensing in both shear and normal directions without the need for multi-layered assembly. Sensor geometry has been tailored to maximize shear force sensitivity using multi-physics finite element simulations. A simple molding microfabrication process is presented to rapidly create the sensing skins with electrode gaps of 20 μ m and sensor spacing of 3 mm. Shear force resolution was found to be as small as 50 mN and tested up to a range of 2 N (dynamic range of 40:1 ). Normal force resolution was found to be 190 mN with a tested range of 8 N (dynamic range of 42:1 ). Single load and multiload tests were conducted and the sensor exhibited intended behavior with low deviations between trials. Spatial tests were conducted on a 2× 2 sensor array and a spatial resolution of 1.5 mm was found.

  12. Ultra-low power high-dynamic range color pixel embedding RGB to r-g chromaticity transformation

    NASA Astrophysics Data System (ADS)

    Lecca, Michela; Gasparini, Leonardo; Gottardi, Massimo

    2014-05-01

    This work describes a novel color pixel topology that converts the three chromatic components from the standard RGB space into the normalized r-g chromaticity space. This conversion is implemented with high-dynamic range and with no dc power consumption, and the auto-exposure capability of the sensor ensures to capture a high quality chromatic signal, even in presence of very bright illuminants or in the darkness. The pixel is intended to become the basic building block of a CMOS color vision sensor, targeted to ultra-low power applications for mobile devices, such as human machine interfaces, gesture recognition, face detection. The experiments show that significant improvements of the proposed pixel with respect to standard cameras in terms of energy saving and accuracy on data acquisition. An application to skin color-based description is presented.

  13. High-dynamic-range microscope imaging based on exposure bracketing in full-field optical coherence tomography.

    PubMed

    Leong-Hoi, Audrey; Montgomery, Paul C; Serio, Bruno; Twardowski, Patrice; Uhring, Wilfried

    2016-04-01

    By applying the proposed high-dynamic-range (HDR) technique based on exposure bracketing, we demonstrate a meaningful reduction in the spatial noise in image frames acquired with a CCD camera so as to improve the fringe contrast in full-field optical coherence tomography (FF-OCT). This new signal processing method thus allows improved probing within transparent or semitransparent samples. The proposed method is demonstrated on 3 μm thick transparent polymer films of Mylar, which, due to their transparency, produce low contrast fringe patterns in white-light interference microscopy. High-resolution tomographic analysis is performed using the technique. After performing appropriate signal processing, resulting XZ sections are observed. Submicrometer-sized defects can be lost in the noise that is present in the CCD images. With the proposed method, we show that by increasing the signal-to-noise ratio of the images, submicrometer-sized defect structures can thus be detected. PMID:27192224

  14. A high-dynamic range (HDR) back-side illuminated (BSI) CMOS image sensor for extreme UV detection

    NASA Astrophysics Data System (ADS)

    Wang, Xinyang; Wolfs, Bram; Bogaerts, Jan; Meynants, Guy; BenMoussa, Ali

    2012-03-01

    This paper describes a back-side illuminated 1 Megapixel CMOS image sensor made in 0.18um CMOS process for EUV detection. The sensor applied a so-call "dual-transfer" scheme to achieve low noise, high dynamic range. The EUV sensitivity is achieved with backside illumination use SOI-based solution. The epitaxial silicon layer is thinned down to less than 3um. The sensor is tested and characterized at 5nm to 30nm illumination. At 17.4nm targeted wavelength, the detector external QE (exclude quantum yield factor) reaches almost 60%. The detector reaches read noise of 1.2 ph- (@17.4nm), i.e. close to performance of EUV photon counting.

  15. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation.

    PubMed

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-01-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 10(6), which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results. PMID:26976363

  16. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

    PubMed Central

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-01-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 106, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results. PMID:26976363

  17. High dynamic range active pixel sensor arrays for digital x-ray imaging using a-Si:H

    SciTech Connect

    Lai, Jackson; Nathan, Arokia; Rowlands, John

    2006-05-15

    Hydrogenated amorphous silicon (a-Si:H) active matrix flat panel imagers have gained considerable significance in large area digital imaging applications, in view of their large area readout capability. Current interests lie in a multifaceted a-Si:H array which is compatible with multiple x-ray imaging modalities. This concept entails a single detector system with sufficient dynamic range and variable signal gain. This article reports on an active pixel sensor (APS) array with high dynamic range and programable gain for multimodality x-ray imaging. Initial results have demonstrated sensitivity from subpicoampere to nanoampere photocurrent, which proves amenable for both low-dosage dynamic imaging and high input static imaging. In addition, the programable system signal gain alleviates problems such as output saturation and ensures signal readout linearity to further improve the exploitable dynamic range. Together with external amplification, this APS circuit delivers the performance needed in terms of signal gain, dynamic range, and readout rate entailed by fluoroscopic and radiographic imaging applications.

  18. Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

    NASA Astrophysics Data System (ADS)

    Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

    2016-03-01

    Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 106, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results.

  19. Noise removal and real-time detail enhancement of high-dynamic-range infrared images with time consistency

    NASA Astrophysics Data System (ADS)

    Garcia, Frederic; Schockaert, Cedric; Mirbach, Bruno

    2015-04-01

    This paper presents a noise removal and image detail enhancement method that accounts for the limitations on human's perception to effectively visualize high-dynamic-range (HDR) infrared (IR) images. In order to represent real world scenes, IR images use to be represented by a HDR that generally exceeds the working range of common display devices (8 bits). Therefore, an effective HDR mapping without losing the perceptibility of details is needed. To do so, we introduce the use of two guided filters (GF) to generate an accurate base and detail image component. A plausibility mask is also generated from the combination of the linear coefficients that result from each GF; an indicator of the spatial detail that enables to identify those regions that are prominent to present noise in the detail image component. Finally, we filter the working range of the HDR along time to avoid global brightness fluctuations in the final 8 bit data representation, which results from combining both detail and base image components using a local adaptive gamma correction (LAGC). The last has been designed according to the human vision characteristics. The experimental evaluation shows that the proposed approach significantly enhances image details in addition to improving the contrast of the entire image. Finally, the high performance of the proposed approach makes it suitable for real word applications.

  20. Sensitivity Gains, Linearity, and Spectral Reproducibility in Nonuniformly Sampled Multidimensional MAS NMR Spectra of High Dynamic Range.

    SciTech Connect

    Suiter, Christopher L.; Paramasivam, Sivakumar; Hou, Guangjin; Sun, Shangjin; Rice, David M.; Hoch, Jeffrey C.; Rovnyak, David S.; Polenova, Tatyana E.

    2014-04-22

    Recently, we have demonstrated that considerable inherent sensitivity gains are attained in MAS NMR spectra acquired by nonuniform sampling (NUS) and introduced maximum entropy interpolation (MINT) processing that assures the linearity of transformation between the time and frequency domains. In this report, we examine the utility of the NUS/MINT approach in multidimensional datasets possessing high dynamic range, such as homonuclear 13C–13C correlation spectra. We demonstrate on model compounds and on 1–73-(U-13C,15N)/74–108-(U-15N) E. coli thioredoxin reassembly, that with appropriately constructed 50 % NUS schedules inherent sensitivity gains of 1.7–2.1-fold are readily reached in such datasets. We show that both linearity and line width are retained under these experimental conditions throughout the entire dynamic range of the signals. Furthermore, we demonstrate that the reproducibility of the peak intensities is excellent in the NUS/MINT approach when experiments are repeated multiple times and identical experimental and processing conditions are employed. Finally, we discuss the principles for design and implementation of random exponentially biased NUS sampling schedules for homonuclear 13C–13C MAS correlation experiments that yield high quality artifact-free datasets.

  1. Design and characterization of the ePix10k: a high dynamic range integrating pixel ASIC for LCLS detectors

    NASA Astrophysics Data System (ADS)

    Caragiulo, P.; Dragone, A.; Markovic, B.; Herbst, R.; Nishimura, K.; Reese, B.; Herrmann, S.; Hart, P.; Blaj, G.; Segal, J.; Tomada, A.; Hasi, J.; Carini, G.; Kenney, C.; Haller, G.

    2015-05-01

    ePix10k is a variant of a novel class of integrating pixel ASICs architectures optimized for the processing of signals in second generation LINAC Coherent Light Source (LCLS) X-Ray cameras. The ASIC is optimized for high dynamic range application requiring high spatial resolution and fast frame rates. ePix ASICs are based on a common platform composed of a random access analog matrix of pixel with global shutter, fast parallel column readout, and dedicated sigma-delta analog to digital converters per column. The ePix10k variant has 100um×100um pixels arranged in a 176×192 matrix, a resolution of 140e- r.m.s. and a signal range of 3.5pC (10k photons at 8keV). In its final version it will be able to sustain a frame rate of 2kHz. A first prototype has been fabricated and characterized. Performance in terms of noise, linearity, uniformity, cross-talk, together with preliminary measurements with bump bonded sensors are reported here.

  2. Modeling a color-rendering operator for high dynamic range images using a cone-response function

    NASA Astrophysics Data System (ADS)

    Choi, Ho-Hyoung; Kim, Gi-Seok; Yun, Byoung-Ju

    2015-09-01

    Tone-mapping operators are the typical algorithms designed to produce visibility and the overall impression of brightness, contrast, and color of high dynamic range (HDR) images on low dynamic range (LDR) display devices. Although several new tone-mapping operators have been proposed in recent years, the results of these operators have not matched those of the psychophysical experiments based on the human visual system. A color-rendering model that is a combination of tone-mapping and cone-response functions using an XYZ tristimulus color space is presented. In the proposed method, the tone-mapping operator produces visibility and the overall impression of brightness, contrast, and color in HDR images when mapped onto relatively LDR devices. The tone-mapping resultant image is obtained using chromatic and achromatic colors to avoid well-known color distortions shown in the conventional methods. The resulting image is then processed with a cone-response function wherein emphasis is placed on human visual perception (HVP). The proposed method covers the mismatch between the actual scene and the rendered image based on HVP. The experimental results show that the proposed method yields an improved color-rendering performance compared to conventional methods.

  3. A case of a superficial spreading melanoma in situ diagnosed via digital dermoscopic monitoring with high dynamic range conversion.

    PubMed

    Sato, Toshitsugu; Tanaka, Masaru

    2014-10-01

    A 48-year-old woman presented with a 3 mm, pigmented macule at her first visit to our clinic. The macule, which showed complete symmetry and a typical network, was tentatively diagnosed as a Clark nevus; a 6-month follow-up was recommended, and the patient returned 7 months later. At the second visit, the lesion had enlarged to a diameter of 5 mm, and dermoscopy revealed that it had maintained its typical pigment network. At this point, evidence-based monitoring would have led to excision but the decision was made to continue monitoring. Owing to poor compliance, the patient went another 2 years without follow-up. When we assess small lesions, such as this, the usefulness of dermoscopy is apparent. Additionally, we examined the benefits and drawbacks of high dynamic range (HDR) conversion of the dermoscopy images and their helpfulness for inspecting small lesions. Although the delicate structures present in the lesion can be recognized by a dermoscopy expert and HDR image conversion has a capacity to highlight important structures, there is also a risk that HDR image conversion may mask some of the structural changes. However, a comparison of the original dermoscopy images with the HDR-converted images provides newly trained dermoscopists the opportunity to recognize new findings and to distinguish the differences in the findings between both the types of images. Therefore, such comparisons might be useful for obtaining an accurate diagnosis by using dermoscopy and HDR image conversion. PMID:25396087

  4. In-line process control for laser welding of titanium by high dynamic range ratio pyrometry and plasma spectroscopy

    NASA Astrophysics Data System (ADS)

    Lempe, B.; Taudt, C.; Baselt, T.; Rudek, F.; Maschke, R.; Basan, F.; Hartmann, P.

    2014-02-01

    The production of complex titanium components for various industries using laser welding processes has received growing attention in recent years. It is important to know whether the result of the cohesive joint meets the quality requirements of standardization and ultimately the customer requirements. Erroneous weld seams can have fatal consequences especially in the field of car manufacturing and medicine technology. To meet these requirements, a real-time process control system has been developed which determines the welding quality through a locally resolved temperature profile. By analyzing the resulting weld plasma received data is used to verify the stability of the laser welding process. The determination of the temperature profile is done by the detection of the emitted electromagnetic radiation from the material in a range of 500 nm to 1100 nm. As detectors, special high dynamic range CMOS cameras are used. As the emissivity of titanium depends on the wavelength, the surface and the angle of radiation, measuring the temperature is a problem. To solve these a special pyrometer setting with two cameras is used. That enables the compensation of these effects by calculating the difference between the respective pixels on simultaneously recorded images. Two spectral regions with the same emissivity are detected. Therefore the degree of emission and surface effects are compensated and canceled out of the calculation. Using the spatially resolved temperature distribution the weld geometry can be determined and the laser process can be controlled. The active readjustment of parameters such as laser power, feed rate and inert gas injection increases the quality of the welding process and decreases the number of defective goods.

  5. Estimation of low dynamic range images from single Bayer image using exposure look-up table for high dynamic range image

    NASA Astrophysics Data System (ADS)

    Lee, Tae-Hyoung; Kyung, Wang-Jun; Lee, Cheol-Hee; Ha, Yeong-Ho

    2011-01-01

    High dynamic range(HDR) imaging is a technique to represent the wider range of luminance from the lightest and darkest area of an image than normal digital imaging techniques. These techniques merge multiple images, called as LDR(low dynamic range) or SDR(standard dynamic range) images which have proper luminance with different exposure steps, to cover the entire dynamic range of real scenes. In the initial techniques, a series of acquisition process for LDR images according to exposure steps are required. However, several acquisition process of LDR images induce ghost artifact for HDR images due to moving objects. Recent researches have tried to reduce the number of LDR images with optimal exposure steps to eliminate the ghost artifacts. Nevertheless, they still require more than three times of acquisition processes, resulting ghosting artifacts. In this paper, we propose an HDR imaging from a single Bayer image with arbitrary exposures without additional acquisition processes. This method first generates new LDR images which are corresponding to each average luminance from user choices, based on Exposure LUTs(look-up tables). Since the LUTs contains relationship between uniform-gray patches and their average luminances according to whole exposure steps in a camera, new exposure steps for any average luminance can be easily estimated by applying average luminance of camera-output image and corresponding exposure step to LUTs. Then, objective LDR images are generated with new exposure steps from the current input image. Additionally, we compensate the color generation of saturated area by considering different sensitivity of each RGB channel from neighbor pixels in the Bayer image. Resulting HDR images are then merged by general method using captured images and estimated images for comparison. Observer's preference test shows that HDR images from the proposed method provides similar appearance with the result images using captured images.

  6. Development and testing of a fast Fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization

    NASA Astrophysics Data System (ADS)

    Thoen, D. J.; Bongers, W. A.; Westerhof, E.; Oosterbeek, J. W.; de Baar, M. R.; van den Berg, M. A.; van Beveren, V.; Bürger, A.; Goede, A. P. H.; Graswinckel, M. F.; Hennen, B. A.; Schüller, F. C.

    2009-10-01

    A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200 000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range.

  7. Development and testing of a fast Fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization.

    PubMed

    Thoen, D J; Bongers, W A; Westerhof, E; Oosterbeek, J W; de Baar, M R; van den Berg, M A; van Beveren, V; Bürger, A; Goede, A P H; Graswinckel, M F; Hennen, B A; Schüller, F C

    2009-10-01

    A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200,000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range. PMID:19895061

  8. Use of alternating-Z doubling in high-dynamic-range tripling: design and evaluation of an optimized prototype tripler

    SciTech Connect

    Auerbach, J. M.; Barker, C.; Eimerl, D.; Milan, D.; Milonni, P. W.

    1998-07-27

    We designed and tested an alternating-Z tripler that consisted of two detuned, Type-1, potassium dihydrogen phosphate (KD*P) doublers and one KD*P mixer. The crystal thicknesses were, respectively, 13, 10 and 10 mm, and the detunings of the doublers were +420 and -520 µrad. All three crystals were fabricated from 80% deuterated KDP. Conversion efficiency was measured and calculated for input 1053- nm pulses with approximately rectangular waveforms and durations of either 1 or 6 ns, and for 20-ns pulses that exhibited intensity variation by a factor of 10. The measured peak conversion efficiency was more than 80%, and energy conversion efficiencies ranged from 62-80% depending on the waveform of the input pulse. The expected large dynamic range in input intensity, 9-10, was observed, and the measured and calculated efficiencies were in excellent agreement.

  9. High Dynamic Range Observations of Solar Coronal Transients at Low Radio Frequencies with a Spectro-correlator

    NASA Astrophysics Data System (ADS)

    Hariharan, K.; Ramesh, R.; Kathiravan, C.; Abhilash, H. N.; Rajalingam, M.

    2016-02-01

    A new antenna system with a digital spectro-correlator that provides high temporal, spectral, and amplitude resolutions has been commissioned at the Gauribidanur Observatory near Bangalore in India. Presently, it is used for observations of the solar coronal transients in the scarcely explored frequency range ≈30-15 MHz. The details of the antenna system, the associated receiver setup, and the initial observational results are reported. Some of the observed transients exhibited quasi-periodicity in their time profiles at discrete frequencies. Estimates of the associated magnetic field strength (B) indicate that B ≈ 0.06-1 G at a typical frequency such as 19.5 MHz.

  10. High order magnetic optics for high dynamic range proton radiography at a kinetic energy 800 MeV

    DOE PAGESBeta

    Sjue, Sky K. L.; Morris, Christopher L.; Merrill, Frank Edward; Mariam, Fesseha Gebre; Saunders, Alexander

    2016-01-14

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the protonimaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane.more » Furthermore, comparison with a series of static calibrationimages demonstrates the model’s accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.« less

  11. Statistical connection of binomial photon counting and photon averaging in high dynamic range beam-scanning microscopy

    PubMed Central

    Muir, Ryan D.; Kissick, David J.; Simpson, Garth J.

    2012-01-01

    Data from photomultiplier tubes are typically analyzed using either counting or averaging techniques, which are most accurate in the dim and bright signal limits, respectively. A statistical means of adjoining these two techniques is presented by recovering the Poisson parameter from averaged data and relating it to the statistics of binomial counting from Kissick et al. [Anal. Chem. 82, 10129 (2010)]. The point at which binomial photon counting and averaging have equal signal to noise ratios is derived. Adjoining these two techniques generates signal to noise ratios at 87% to approaching 100% of theoretical maximum across the full dynamic range of the photomultiplier tube used. The technique is demonstrated in a second harmonic generation microscope. PMID:22535131

  12. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV

    NASA Astrophysics Data System (ADS)

    Sjue, S. K. L.; Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A.

    2016-01-01

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model's accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.

  13. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV.

    PubMed

    Sjue, S K L; Mariam, F G; Merrill, F E; Morris, C L; Saunders, A

    2016-01-01

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model's accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets. PMID:26827356

  14. Statistical connection of binomial photon counting and photon averaging in high dynamic range beam-scanning microscopy.

    PubMed

    Muir, Ryan D; Kissick, David J; Simpson, Garth J

    2012-04-23

    Data from photomultiplier tubes are typically analyzed using either counting or averaging techniques, which are most accurate in the dim and bright signal limits, respectively. A statistical means of adjoining these two techniques is presented by recovering the Poisson parameter from averaged data and relating it to the statistics of binomial counting from Kissick et al. [Anal. Chem. 82, 10129 (2010)]. The point at which binomial photon counting and averaging have equal signal to noise ratios is derived. Adjoining these two techniques generates signal to noise ratios at 87% to approaching 100% of theoretical maximum across the full dynamic range of the photomultiplier tube used. The technique is demonstrated in a second harmonic generation microscope. PMID:22535131

  15. Imaging X-ray detector front-end with high dynamic range: IDeF-X HD

    NASA Astrophysics Data System (ADS)

    Gevin, O.; Lemaire, O.; Lugiez, F.; Michalowska, A.; Baron, P.; Limousin, O.; Delagnes, E.

    2012-12-01

    Presented circuit, IDeF-X HD (Imaging Detector Front-end) is a member of the IDeF-X ASICs family for space applications. It has been optimized for a half millimeter pitch CdTe or CdZnTe pixelated detector arranged in 16×16 array. It is aimed to operate in the hard X-ray range from few keV up to 250 keV or more. The ASIC has been realized in AMS 0.35 μm CMOS process. The IDeF-X HD is a 32 channel analog front-end with self-triggering capability. The architecture of the analog channel includes a chain of charge sensitive amplifier with continuous reset system and non-stationary noise suppressor, adjustable gain stage, pole-zero cancellation stage, adjustable shaping time low pass filter, baseline holder and peak detector with discriminator. The power consumption of the IDeF-X HD is 800 μW per channel. With the in-channel variable gain stage the nominal 250 keV dynamic range of the ASIC can be extended up to 1 MeV anticipating future applications using thick sensors. Measuring the noise performance without a detector at the input with minimized leakage current (programmable) at the input, we achieved ENC of 33 electrons rms at 10.7 μs peak time. Measurements with CdTe detector show good energy resolution FWHM of 1.1 keV at 60 keV and 4.3 keV at 662 keV with detection threshold below 4 keV. In addition, an absolute temperature sensor has been integrated with resolution of 1.5 °C.

  16. Measuring phased-array antenna beampatterns with high dynamic range for the Murchison Widefield Array using 137 MHz ORBCOMM satellites

    NASA Astrophysics Data System (ADS)

    Neben, A. R.; Bradley, R. F.; Hewitt, J. N.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Johnston-Hollitt, M.; Kaplan, D. L.; Lonsdale, C. J.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Ord, S. M.; Prabu, T.; Shankar, N. Udaya; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.

    2015-07-01

    Detection of the fluctuations in a 21 cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibration and image quality, both of which necessitate accurate primary beam models. The Murchison Widefield Array (MWA) uses phased-array antenna elements which maximize collecting area at the cost of complexity. To quantify their performance, we have developed a novel beam measurement system using the 137 MHz ORBCOMM satellite constellation and a reference dipole antenna. Using power ratio measurements, we measure the in situ beampattern of the MWA antenna tile relative to that of the reference antenna, canceling the variation of satellite flux or polarization with time. We employ angular averaging to mitigate multipath effects (ground scattering) and assess environmental systematics with a null experiment in which the MWA tile is replaced with a second-reference dipole. We achieve beam measurements over 30 dB dynamic range in beam sensitivity over a large field of view (65% of the visible sky), far wider and deeper than drift scans through astronomical sources allow. We verify an analytic model of the MWA tile at this frequency within a few percent statistical scatter within the full width at half maximum. Toward the edges of the main lobe and in the sidelobes, we measure tens of percent systematic deviations. We compare these errors with those expected from known beamforming errors.

  17. Rapid Protein Global Fold Determination Using Ultrasparse Sampling, High-Dynamic Range Artifact Suppression, and Time-Shared NOESY

    PubMed Central

    Coggins, Brian E.; Werner-Allen, Jonathan W.; Yan, Anthony; Zhou, Pei

    2012-01-01

    In structural studies of large proteins by NMR, global fold determination plays an increasingly important role in providing a first look at a target’s topology and reducing assignment ambiguity in NOESY spectra of fully-protonated samples. In this work, we demonstrate the use of ultrasparse sampling, a new data processing algorithm, and a 4-D time-shared NOESY experiment (1) to collect all NOEs in 2H/13C/15N-labeled protein samples with selectively-protonated amide and ILV methyl groups at high resolution in only four days, and (2) to calculate global folds from this data using fully automated resonance assignment. The new algorithm, SCRUB, incorporates the CLEAN method for iterative artifact removal, but applies an additional level of iteration, permitting real signals to be distinguished from noise and allowing nearly all artifacts generated by real signals to be eliminated. In simulations with 1.2% of the data required by Nyquist sampling, SCRUB achieves a dynamic range over 10000:1 (250× better artifact suppression than CLEAN) and completely quantitative reproduction of signal intensities, volumes, and lineshapes. Applied to 4-D time-shared NOESY data, SCRUB processing dramatically reduces aliasing noise from strong diagonal signals, enabling the identification of weak NOE crosspeaks with intensities 100× less than diagonal signals. Nearly all of the expected peaks for interproton distances under 5 Å were observed. The practical benefit of this method is demonstrated with structure calculations for 23 kDa and 29 kDa test proteins using the automated assignment protocol of CYANA, in which unassigned 4-D time-shared NOESY peak lists produce accurate and well-converged global fold ensembles, whereas 3-D peak lists either fail to converge or produce significantly less accurate folds. The approach presented here succeeds with an order of magnitude less sampling than required by alternative methods for processing sparse 4-D data. PMID:22946863

  18. Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control

    SciTech Connect

    Bongers, W. A.; Beveren, V. van; Westerhof, E.; Goede, A. P. H.; Krijger, B.; Berg, M. A. van den; Graswinckel, M. F.; Schueller, F. C.; Thoen, D. J.; Nuij, P. J. W. M.; Baar, M. R. de; Donne, A. J. H.; Hennen, B. A.; Kantor, M.

    2011-06-15

    An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.

  19. Development of a high dynamic range spectroscopic system for observation of neutral hydrogen atom density distribution in Large Helical Device core plasma

    SciTech Connect

    Fujii, K. Atsumi, S.; Watanabe, S.; Shikama, T.; Hasuo, M.; Goto, M.; Morita, S.

    2014-02-15

    We report development of a high dynamic range spectroscopic system comprising a spectrometer with 30% throughput and a camera with a low-noise fast-readout complementary metal-oxide semiconductor sensor. The system achieves a 10{sup 6} dynamic range (∼20 bit resolution) and an instrumental function approximated by a Voigt profile with Gauss and Lorentz widths of 31 and 0.31 pm, respectively, for 656 nm light. The application of the system for line profile observations of the Balmer-α emissions from high temperature plasmas generated in the Large Helical Device is also presented. In the observed line profiles, emissions are detected in far wings more than 1.0 nm away from the line center, equivalent to neutral hydrogen atom kinetic energies above 1 keV. We evaluate atom density distributions in the core plasma by analyzing the line profiles.

  20. High dynamic range charge measurements

    DOEpatents

    De Geronimo, Gianluigi

    2012-09-04

    A charge amplifier for use in radiation sensing includes an amplifier, at least one switch, and at least one capacitor. The switch selectively couples the input of the switch to one of at least two voltages. The capacitor is electrically coupled in series between the input of the amplifier and the input of the switch. The capacitor is electrically coupled to the input of the amplifier without a switch coupled therebetween. A method of measuring charge in radiation sensing includes selectively diverting charge from an input of an amplifier to an input of at least one capacitor by selectively coupling an output of the at least one capacitor to one of at least two voltages. The input of the at least one capacitor is operatively coupled to the input of the amplifier without a switch coupled therebetween. The method also includes calculating a total charge based on a sum of the amplified charge and the diverted charge.

  1. Developing A Low-frequency Interferometer For Detecting The Epoch Of Reionization: Correlation, Calibration, And High Dynamic-range Imaging With Paper

    NASA Astrophysics Data System (ADS)

    Parsons, Aaron; PAPER Team

    2009-01-01

    The Precision Array for Probing the Epoch of Reionization (PAPER) is a low-frequency interferometer being developed to detect cosmic reionization via fluctuations in the brightness temperature of the 21cm hyperfine transition of neutral hydrogen in the early intergalactic medium. Interfering with the direct detection of a global reionization signature are a myriad of astrophysical foregrounds, including polarized galactic synchrotron emission, continuum point-sources, and galactic/extra-galactic free-free emission. Suppression of these foregrounds will require extraordinary calibration and high dynamic-range imaging, as well as large numbers of antennas to achieve the necessary sensitivity in the region of the power spectrum where the reionization signal peaks relative to them. Addressing the challenge of correlating large numbers of antennas, we have developed a flexible correlator architecture that scales to hundreds of antennas. This correlator is based on Field-Programmable Gate Array processors connected by a 10 Gb Ethernet switch, and programmed using a parameterized signal processing library. We demonstrate how this work has dramatically decreased correlator development time, and has enabled PAPER to grow as a series of deployments of increasing size. Calibration and high dynamic-range imaging with low-frequency interferometers are exacerbated by wide bandwidths and large fields-of-view (FoV). To simplify the calibration process when an interferometer consistently has many strong sources simultaneously in its FoV, we present a fringe-rate/delay filtering technique to isolating source fluxes. This is implemented as part of Astronomical Interferometry in PYthon (AIPY), a new open-source software toolkit that facilitates exploration and algorithm development by modularizing data processing and visibility simulation. We present the application of this toolkit to various aspects of PAPER calibration. Finally, we present the first all-sky map and point source

  2. Shadow attenuation with high dynamic range images. Creating RGB images that allow feature classification in areas otherwise obscured by shadow or oversaturation.

    PubMed

    Cox, Samuel E; Booth, D Terrance

    2009-11-01

    Shadow often interferes with accurate image analysis. To mitigate shadow effects in near-earth imagery (2 m above ground level), we created high dynamic range (HDR) nadir images and used them to measure grassland ground cover. HDR composites were created by merging three differentially exposed images spanning a wide exposure range and resulted in lightened shadows. HDR images showed more detail; reduced the numbers of pure black, pure white, and pixels visually indistinguishable from black and white; reapportioned skewed luma values towards a normal distribution; and increased the Euclidean distance between litter and bare ground RGB values--allowing increased feature separation; all of which facilitated an increase in real feature classification through manual image analysis. Drawbacks to the method included decreased image sharpness due to minor misalignment of images or moving vegetation, time required to create HDR images, and difficulty with acquiring primary images from a moving platform. We conclude that HDR imagery can provide more accurate measurements of bare soil cover for ecosystem monitoring and assessment. PMID:18972218

  3. High dynamic range emission measurements of shocked energetic materials: Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)

    NASA Astrophysics Data System (ADS)

    Bassett, Will P.; Dlott, Dana D.

    2016-06-01

    A new emission apparatus with high time resolution and high dynamic range was used to study shock-induced ignition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine in the form of ultrafine powder (4 ± 3 μm particle size), over a range of impact velocities (0.8-4.3 km s-1) and impact durations (2.5-16 ns). A graybody model was used to extract graybody emissivities and time-dependent temperatures from a few ns to 100 μs. The emission transients consisted of three parts: a 6700 K nanosecond burst during the shocks, a 4000-4500 K temperature spike near 0.3 μs followed by a ˜3300 K tail extending out to ˜100 μs. These temperatures varied remarkably little with impact velocity and duration, while the emission intensities and emissivities changed by over an order of magnitude. The emissivity changes were interpreted with a hot spot model, where hot spot temperatures reached a maximum of 6700 K and the hot spot volume fractions increased from 5% to 100% as impact velocity increased from 1 to 3 km s-1. Changing shock durations in the 2.5-16 ns range had noticeable effects on the microsecond emission. The 0.3 μs temperature spike was much smaller or absent with 2.5 ns shocks, but prominent with longer durations. An explanation for these effects was put forth that invoked the formation of carbon-rich clusters during the shock. In this view, cluster formation was minimal with 2.5 ns shocks, but longer-duration shocks produced increasingly larger clusters, and the 0.3 μs temperature spikes represented cluster ignition.

  4. Real-time visualization of low contrast targets from high-dynamic range infrared images based on temporal digital detail enhancement filter

    NASA Astrophysics Data System (ADS)

    Garcia, Frederic; Schockaert, Cedric; Mirbach, Bruno

    2015-11-01

    An image detail enhancement method to effectively visualize low contrast targets in high-dynamic range (HDR) infrared (IR) images is presented regardless of the dynamic range width. In general, high temperature dynamics from real-world scenes used to be encoded in a 12 or 14 bits IR image. However, the limitations of the human visual perception, from which no more than 128 shades of gray are distinguishable, and the 8-bit working range of common display devices make necessary an effective 12/14 bits HDR mapping into the 8-bit data representation. To do so, we propose to independently treat the base and detail image components that result from splitting the IR image using two dedicated guided filters. We also introduce a plausibility mask from which those regions that are prominent to present noise are accurately defined to be explicitly tackled to avoid noise amplification. The final 8-bit data representation results from the combination of the processed detail and base image components and its mapping to the 8-bit domain using an adaptive histogram-based projection approach. The limits of the histogram are accommodated through time in order to avoid global brightness fluctuations between frames. The experimental evaluation shows that the proposed noise-aware approach preserves low contrast details with an overall contrast enhancement of the image. A comparison with widely used HDR mapping approaches and runtime analysis is also provided. Furthermore, the proposed mathematical formulation enables a real-time adjustment of the global contrast and brightness, letting the operator adapt to the visualization display device without nondesirable artifacts.

  5. Signal-to-noise ratio improvements in laser flow diagnostics using time-resolved image averaging and high dynamic range imaging

    NASA Astrophysics Data System (ADS)

    Giassi, Davide; Long, Marshall B.

    2016-08-01

    Two alternative image readout approaches are demonstrated to improve the signal-to-noise ratio (SNR) in temporally resolved laser-based imaging experiments of turbulent phenomena. The first method exploits the temporal decay characteristics of the phosphor screens of image intensifiers when coupled to an interline-transfer CCD camera operated in double-frame mode. Specifically, the light emitted by the phosphor screen, which has a finite decay constant, is equally distributed and recorded over the two sequential frames of the detector so that an averaged image can be reconstructed. The characterization of both detector and image intensifier showed that the technique preserves the correct quantitative information, and its applicability to reactive flows was verified using planar Rayleigh scattering and tested with the acquisition of images of both steady and turbulent partially premixed methane/air flames. The comparison between conventional Rayleigh results and the averaged ones showed that the SNR of the averaged image is higher than the conventional one; with the setup used in this work, the gain in SNR was seen to approach 30 %, for both the steady and turbulent cases. The second technique uses the two-frame readout of an interline-transfer CCD to increase the image SNR based on high dynamic range imaging, and it was tested in an unsteady non-reactive flow of Freon-12 injected in air. The result showed a 15 % increase in the SNR of the low-pixel-count regions of an image, when compared to the pixels of a conventionally averaged one.

  6. Reconstruction of High Dynamic Range Images: Simulations of LBT Observations of a Stellar Jet, a Pathfinder Study for Future AO-Assisted Giant Telescopes

    NASA Astrophysics Data System (ADS)

    La Camera, A.; Antoniucci, S.; Bertero, M.; Boccacci, P.; Lorenzetti, D.; Nisini, B.; Arcidiacono, C.

    2014-02-01

    We present simulated Large Binocular Telescope (LBT) infrared narrow-band observations of a star-jet system, in conjunction with improved and optimized deconvolution and image reconstruction algorithms, considering two cases of interest: single-dish direct imaging with an AO-assisted camera and imaging through a Fizeau interferometer that combines the beams of the two mirrors of LBT. We aim at understanding what accuracy can be obtained with the use of present AO-assisted large telescopes (such as LBT) and what improvements an interferometric instrument (such as LINC-NIRVANA) will be able to provide. The proposed deconvolution method is based on the target decomposition as a sum of a point source (the star) and an extended source (the jet). By assuming Poisson noise we add to the negative logarithm of the likelihood a regularization term enforcing smoothness of the jet component. Finally, we use a Richardson-Lucy-like method for the minimization of this function. This approach is an improvement of a method proposed by Lucy in 1994 for accurate photometric restoration of HST images and called two channel photometric restoration. We denote the new method as the multi-component Richardson-Lucy (MC-RL) method. The analysis of the reconstructed objects shows that the MC-RL method applied to the interferometric observations allows us to evaluate the width and the spatial intensity profile of the jet down to 20 mas with an accuracy better than about 20% in the best case of a central star fainter than 10 mag. These limits allow us to obtain a very good reconstruction of the jet acceleration region very close to the exciting source, which would provide fundamental scientific information on the jet collimation degree and eventually on its launching mechanism. As concerns the proposed MC-RL method, it demonstrates a good performance in the reconstruction of images with a very high dynamic range. It can be improved in several directions, by increasing both its efficiency

  7. High dynamic range measurement of spectral responsivity and linearity of a radiation thermometer using a super-continuum laser and LEDs

    SciTech Connect

    Yoo, Y. S.; Lee, D. H.; Park, C. W.; Park, S. N.

    2013-09-11

    To realize the temperature scale above the freezing point of silver according to the definition of ITS-90, the dynamic range of the spectral responsivity is one of the most important factors which limit its uncertainty. When the residual spectral response at both side bands of a spectral band is not negligible, a significant uncertainty can be caused by a low dynamic range of the spectral responsivity measurement. In general, incandescent lamps are used to measure the spectral responsivity and the linearity. The dynamic range of the spectral responsivity measurement is often limited by a trade-off with the desired spectral resolution, which is less than 6 decades. Nonlinearity is another limiting fact of uncertainties of the temperature scale. Tungsten lamps have disadvantage in the nonlinearity measurements in terms of adjustability of radiance level and spectral selectivity. We report spectral responsivity measurements of which the measurable dynamic range is enhanced 50 times after replacing a QTH lamp with a super continuum laser. We also present a spectrally selected linearity measurement over a wide dynamic range using high-brightness light emitting diode arrays to observe a slight saturation of linearity.

  8. High dynamic range measurement of spectral responsivity and linearity of a radiation thermometer using a super-continuum laser and LEDs

    NASA Astrophysics Data System (ADS)

    Yoo, Y. S.; Lee, D. H.; Park, C. W.; Park, S. N.

    2013-09-01

    To realize the temperature scale above the freezing point of silver according to the definition of ITS-90, the dynamic range of the spectral responsivity is one of the most important factors which limit its uncertainty. When the residual spectral response at both side bands of a spectral band is not negligible, a significant uncertainty can be caused by a low dynamic range of the spectral responsivity measurement. In general, incandescent lamps are used to measure the spectral responsivity and the linearity. The dynamic range of the spectral responsivity measurement is often limited by a trade-off with the desired spectral resolution, which is less than 6 decades. Nonlinearity is another limiting fact of uncertainties of the temperature scale. Tungsten lamps have disadvantage in the nonlinearity measurements in terms of adjustability of radiance level and spectral selectivity. We report spectral responsivity measurements of which the measurable dynamic range is enhanced 50 times after replacing a QTH lamp with a super continuum laser. We also present a spectrally selected linearity measurement over a wide dynamic range using high-brightness light emitting diode arrays to observe a slight saturation of linearity.

  9. Ultra-High-Efficiency Strong Cation Exchange LC/RPLC/MS/MS for High Dynamic Range Characterization of the Human Plasma Proteome

    SciTech Connect

    Shen, Yufeng; Jacobs, Jon M.; Camp, David G.; Fang, Ruihua; Moore, Ronald J.; Smith, Richard D.; Xiao, Wenzhong; Davis, Ronald W.; Tompkins, Ronald G.

    2004-02-15

    In this study, we report a comprehensive approach for ultrahigh-efficiency separations by liquid chromatography (LC)/tandem mass spectrometry (MS/MS) for broad protein characterization of human plasma. The power of this approach is demonstrated by the confident identification of 1062 human plasma proteins based upon identification of 2992 tryptic peptides using highly conservative SEQUEST search criteria from a non-depleted human plasma sample. The approach provides a dynamic range of {approx}9 orders of magnitude in protein abundance using conventional ion trap MS/MS, which enabled identification of pg/mL concentration human plasma proteins (e.g. cytokines) co-existing with mg/mL-level human serum albumin. This dynamic range was obtained by combining high-efficiency reversed-phase (RP) LC coupled with efficient pre-fractionation strong cation exchange (SCX) LC to achieve ultrahigh-efficiency separations. A single-dimension, high-efficiency RPLC provided a protein identification dynamic range of 4 orders of magnitude in protein content and identified 433 human plasma proteins; while the ultrahigh-efficiency SCXLC/RPLC (i.e. 15 fractions from SCXLC), with the assistance of the SCXLC-sample component concentration (up to 102 fold), extended the protein identification dynamic range to {approx}9 orders of magnitude in protein content, identifying 822 human plasma proteins; combination of single- and two-dimension LC/MS/MS led to identification of 1062 human plasma proteins.

  10. REVIEW ARTICLE: From single photons to milliwatt radiant power—electron storage rings as radiation sources with a high dynamic range

    NASA Astrophysics Data System (ADS)

    Klein, Roman; Thornagel, Reiner; Ulm, Gerhard

    2010-10-01

    The spectral radiant intensity of synchrotron radiation from electron storage rings can be calculated from basic electrodynamic relations (Schwinger equation) and it is directly proportional to the stored electron beam current, i.e. the number of stored electrons. With the necessary equipment installed to measure and control the electron beam current over a wide dynamic range, the radiant intensity of the synchrotron radiation can be adjusted accordingly without changing the spectrum. This is done, e.g., at the Metrology Light Source (MLS), the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt. The MLS is operated as a primary radiation source standard from the near IR up to the soft x-ray region and its operational parameters can be adjusted and accurately measured in a wide range: the electron beam current can be varied from 1 pA (one stored electron) up to 200 mA and thus the radiant intensity can be changed by more than 11 decades. The photon flux or radiant power for typical angular acceptances can thus be varied from single photons to milliwatts. This is a very powerful tool, e.g., for the characterization of the linearity of the response of radiation detectors or for the calibration of photon counting detectors. In this article we present an overview of past, current and possible future activities exploiting this feature.

  11. Towards a microchannel-based X-ray detector with two-dimensional spatial and time resolution and high dynamic range

    SciTech Connect

    Adams, Bernhard W.; Mane, Anil; Elam, Jeffrey; Obaid, Razib; Wetstein, Matthew J.

    2015-09-01

    X-ray detectors that combine two-dimensional spatial resolution with a high time resolution are needed in numerous applications of synchrotron radiation. Most detectors with this combination of capabilities are based on semiconductor technology and are therefore limited in size. Furthermore, the time resolution is often realised through rapid time-gating of the acquisition, followed by a slower readout. Here, a detector technology is realised based on relatively inexpensive microchannel plates that uses GHz waveform sampling for a millimeter-scale spatial resolution and better than 100 ps time resolution. The technology is capable of continuous streaming of time- and location-tagged events at rates greater than 10(7) events per cm(2). Time-gating can be used for improved dynamic range.

  12. Ultrafast laser with an average power of 120 W at 515 nm and a highly dynamic repetition rate in the MHz range for novel applications in micromachining

    NASA Astrophysics Data System (ADS)

    Harth, F.; Piontek, M. C.; Herrmann, T.; L'huillier, J. A.

    2016-03-01

    A new generation of resonant scanners in the kHz-range shows ultra-high deflection speeds of more than 1000m/s but suffer from an inherent nonlinear mirror oscillation. If this oscillation is not compensated, a typical bitmap, written point by point, would be strongly distorted because of the decreasing spot distance at the turning point of the scanning mirror. However, this can be avoided by a dynamic adaption of the repetition rate (RR) of the ultrafast laser. Since resonant scanners are operated in the 10 kHz-range, this means that the RR has to be continuously swept up to several 10 000 times per second between e.g. 5MHz and 10 MHz. High-speed continuous adaption of the RR could also optimize laser micromachining of narrow curved geometries, where nowadays a time consuming approximation with numerous vectors is required. We present a laser system, which is capable of sweeping the RR more than 32 000 times per second between 5MHz and 10MHz at an average output power of more than 120W at 515nm with a pulse duration of about 40 ps. The laser consists of a semiconductor oscillator, a 3-stage fiber pre-amplifier, a solid state InnoSlab power amplifier and a SHG stage. We systematically analyzed the dynamic of the laser system as well as the spectral and temporal behavior of the optical pulses. Switching the repetition rate typically causes a varying pulse energy, which could affect the machining quality over one scanning line. This effect will be analyzed and discussed. Possible techniques to compensate or avoid this effect will be considered.

  13. High dynamic GPS receiver validation demonstration

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Statman, J. I.; Vilnrotter, V. A.

    1985-01-01

    The Validation Demonstration establishes that the high dynamic Global Positioning System (GPS) receiver concept developed at JPL meets the dynamic tracking requirements for range instrumentation of missiles and drones. It was demonstrated that the receiver can track the pseudorange and pseudorange rate of vehicles with acceleration in excess of 100 g and jerk in excess of 100 g/s, dynamics ten times more severe than specified for conventional High Dynamic GPS receivers. These results and analytic extensions to a complete system configuration establish that all range instrumentation requirements can be met. The receiver can be implemented in the 100 cu in volume required by all missiles and drones, and is ideally suited for transdigitizer or translator applications.

  14. High dynamic, low volume GPS receiver

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.

    1983-01-01

    A new GPS receiver concept and design are presented to meet the high dynamic and low volume requirements for range applications in missiles and drones. The receiver has the potential to satisfy all range requirements with one basic receiver, which has significant potential economic benefit over the alternate approach of using a family of receivers, each tailored for specific applications. The main new concept is to use approximate maximum likelihood estimates of pseudo range and range-rate, rather than tracking with carrier phase locked loops and code delay locked loops. Preliminary analysis indicates that receivers accelerating at 50 g or more can track with position errors due to acceleration of approximately 0.2 m/g, or 10 m at 50 g. Implementation is almost entirely digital to meet the low volume requirements.

  15. High-dynamic GPS tracking

    NASA Technical Reports Server (NTRS)

    Hinedi, S.; Statman, J. I.

    1988-01-01

    The results of comparing four different frequency estimation schemes in the presence of high dynamics and low carrier-to-noise ratios are given. The comparison is based on measured data from a hardware demonstration. The tested algorithms include a digital phase-locked loop, a cross-product automatic frequency tracking loop, and extended Kalman filter, and finally, a fast Fourier transformation-aided cross-product frequency tracking loop. The tracking algorithms are compared on their frequency error performance and their ability to maintain lock during severe maneuvers at various carrier-to-noise ratios. The measured results are shown to agree with simulation results carried out and reported previously.

  16. Modular optimization of multi-gene pathways for fumarate production.

    PubMed

    Chen, Xiulai; Zhu, Pan; Liu, Liming

    2016-01-01

    Microbial fumarate production from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. Here, we report a modular engineering approach that systematically removed metabolic pathway bottlenecks and led to significant titer improvements in a multi-gene fumarate metabolic pathway. On the basis of central pathway architecture, yeast fumarate biosynthesis was re-cast into three modules: reduction module, oxidation module, and byproduct module. We targeted reduction module and oxidation module to the cytoplasm and the mitochondria, respectively. Combinatorially tuning pathway efficiency by constructing protein fusions RoMDH-P160A and KGD2-SUCLG2 and optimizing metabolic balance by controlling genes RoPYC, RoMDH-P160A, KGD2-SUCLG2 and SDH1 expression strengths led to significantly improved fumarate production (20.46 g/L). In byproduct module, synthetizing DNA-guided scaffolds and designing sRNA switchs enabled further production improvement up to 33.13 g/L. These results suggest that modular pathway engineering can systematically optimize biosynthesis pathways to enable an efficient production of fumarate. PMID:26241189

  17. GPS high dynamic receiver tracking demonstration results

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Statman, J. I.; Vilnrotter, V. A.

    1985-01-01

    Demonstration results are presented for a high dynamic GPS receiver. The receiver tested is a breadboard unit capable of tracking one simulated satellite signal in pseudorange and range rate. The receiver makes approximate maximum likelihood estimates of pseudorange and range rate each 20 ms, and tracks these observables using a third order filter with a time constant of 0.14 s. Carrier phase is not tracked, which eliminates the typical failure mode of loss of carrier lock associated with PLLs at high dynamics. The receiver tracks with pseudorange lag errors of under 0.06 m when subjected to simulated 50 g turns with 40 g/s peak jerk. Pseudorange errors due to receiver noise alone are approximately 0.6 m rms at a carrier power to noise spectral density ratio of 34 dB-Hz. The tracking threshold SNR is approximately 28 dB-Hz, which provides 12 dB margin relative to the 40 dB-Hz that occurs with minimum specified satellite signal strength, 3.5 dB system noise figure, and 0 dBi antenna gain.

  18. Companding technique for high dynamic range measurements using Gafchromic films

    SciTech Connect

    Van den Heuvel, Frank; Crijns, Wouter; Defraene, Gilles

    2011-12-15

    Purpose: To introduce a methodology to perform dose measurements using Gafchromic films which can span several decades of dose levels. Methods: The technique is based on a rescaling approach using different films irradiated at different dose levels. This is combined with a registration protocol correcting positioning and scaling factors for each film. The methodology is validated using TLD's for out-of-field doses. Furthermore, two examples are provided using the technique to characterize small sized radiosurgery cones and compared with measurements made with a pinpoint chamber. Results: Excellent agreement with TLD, planning systems and measurement was found. The superior resolution of the film technique was apparent. Conclusions: The authors have introduced a new technique allowing users to quantify very low doses in conjunction with commissioning measurements. The use of film also provides 2D information on beam characteristics in high resolution measurements.

  19. High Dynamic Range Cognitive Radio Front Ends: Architecture to Evaluation

    NASA Astrophysics Data System (ADS)

    Ashok, Arun; Subbiah, Iyappan; Varga, Gabor; Schrey, Moritz; Heinen, Stefan

    2016-07-01

    Advent of TV white space digitization has released frequencies from 470 MHz to 790 MHz to be utilized opportunistically. The secondary user can utilize these so called TV spaces in the absence of primary users. The most important challenge for this coexistence is mutual interference. While the strong TV stations can completely saturate the receiver of the cognitive radio (CR), the cognitive radio spurious tones can disturb other primary users and white space devices. The aim of this paper is to address the challenges for enabling cognitive radio applications in WLAN and LTE. In this process, architectural considerations for the design of cognitive radio front ends are discussed. With high-IF converters, faster and flexible implementation of CR enabled WLAN and LTE are shown. The effectiveness of the architecture is shown by evaluating the CR front ends for compliance of standards namely 802.11b/g (WLAN) and 3GPP TS 36.101 (LTE).

  20. The design of high dynamic range ROIC for IRFPAs

    NASA Astrophysics Data System (ADS)

    Jiang, Dazhao; Liang, Qinghua; Zhang, Qiwen; Chen, Honglei; Ding, Ruijun

    2015-10-01

    The charge packet readout integrated circuit (ROIC) technology for the IRFPAs is introduced, which can realize that every pixel achieves a very high capacity of the electrons storage, and it also improves the performance of the SNR and reduces the saturation possibility of the pixels. The ROIC for the LWIR requires ability that obtaining high capacity for storing electrons. For the conventional ROIC, the maximum charge capacity is determined by the integration capacitance and the operating voltage, it can achieve a high charge capacity through increasing the area of the integration capacitor or raising the operating voltage. And this paper would introduce a digital method of ROIC that can achieve a very high charge capacity. The circuit architecture of this approach includes the following parts, a preamplifier, a comparator, a counter, and memory arrays. And the maximum charge capacity of the pixel is determined by the counter bits. This new method can achieve a high charge capacity more than 1Ge- every pixel and output the digital signal directly, while that of conventional ROIC is less than 50Me- and output the analog signal from the pixel. In this new circuit, the comparator is a important module, as the integration voltage value need compare with threshold voltage through the comparator all the time during the integration period, and we will discuss the influence of the comparator. This work design the circuit with the CSMC 0.35um CMOS technology, and the simulation use the spectre model.

  1. Shaper design in CMOS for high dynamic range

    DOEpatents

    De Geronimo, Gianluigi; Li, Shaorui

    2015-06-30

    An analog filter is presented that comprises a chain of filter stages, a feedback resistor for providing a negative feedback, and a feedback capacitor for providing a positive feedback. Each filter stage has an input node and an output node. The output node of a filter stage is connected to the input node of an immediately succeeding filter stage through a resistor. The feedback resistor has a first end connected to the output node of the last filter stage along the chain of filter stages, and a second end connected to the input node of a first preceding filter stage. The feedback capacitor has a first end connected to the output node of one of the chain of filter stages, and a second end connected to the input node of a second preceding filter stage.

  2. Detecting sequence homology at the gene cluster level with MultiGeneBlast.

    PubMed

    Medema, Marnix H; Takano, Eriko; Breitling, Rainer

    2013-05-01

    The genes encoding many biomolecular systems and pathways are genomically organized in operons or gene clusters. With MultiGeneBlast, we provide a user-friendly and effective tool to perform homology searches with operons or gene clusters as basic units, instead of single genes. The contextualization offered by MultiGeneBlast allows users to get a better understanding of the function, evolutionary history, and practical applications of such genomic regions. The tool is fully equipped with applications to generate search databases from GenBank or from the user's own sequence data. Finally, an architecture search mode allows searching for gene clusters with novel configurations, by detecting genomic regions with any user-specified combination of genes. Sources, precompiled binaries, and a graphical tutorial of MultiGeneBlast are freely available from http://multigeneblast.sourceforge.net/. PMID:23412913

  3. Multi-Gene Detection and Identification of Mosquito-Borne RNA Viruses Using an Oligonucleotide Microarray

    PubMed Central

    Grubaugh, Nathan D.; McMenamy, Scott S.; Turell, Michael J.; Lee, John S.

    2013-01-01

    Background Arthropod-borne viruses are important emerging pathogens world-wide. Viruses transmitted by mosquitoes, such as dengue, yellow fever, and Japanese encephalitis viruses, infect hundreds of millions of people and animals each year. Global surveillance of these viruses in mosquito vectors using molecular based assays is critical for prevention and control of the associated diseases. Here, we report an oligonucleotide DNA microarray design, termed ArboChip5.1, for multi-gene detection and identification of mosquito-borne RNA viruses from the genera Flavivirus (family Flaviviridae), Alphavirus (Togaviridae), Orthobunyavirus (Bunyaviridae), and Phlebovirus (Bunyaviridae). Methodology/Principal Findings The assay utilizes targeted PCR amplification of three genes from each virus genus for electrochemical detection on a portable, field-tested microarray platform. Fifty-two viruses propagated in cell-culture were used to evaluate the specificity of the PCR primer sets and the ArboChip5.1 microarray capture probes. The microarray detected all of the tested viruses and differentiated between many closely related viruses such as members of the dengue, Japanese encephalitis, and Semliki Forest virus clades. Laboratory infected mosquitoes were used to simulate field samples and to determine the limits of detection. Additionally, we identified dengue virus type 3, Japanese encephalitis virus, Tembusu virus, Culex flavivirus, and a Quang Binh-like virus from mosquitoes collected in Thailand in 2011 and 2012. Conclusions/Significance We demonstrated that the described assay can be utilized in a comprehensive field surveillance program by the broad-range amplification and specific identification of arboviruses from infected mosquitoes. Furthermore, the microarray platform can be deployed in the field and viral RNA extraction to data analysis can occur in as little as 12 h. The information derived from the ArboChip5.1 microarray can help to establish public health

  4. Sub-genomic level sequence analysis of the aquaporin multi-gene family in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaporins function mainly as water transport channel proteins that facilitate water movement across intracellular and intercellular membranes in most living organisms. Plant aquaporins belong to a multi-gene family and are commonly categorized into 5 subfamilies according to sequence similarity. Re...

  5. Combining classifiers generated by multi-gene genetic programming for protein fold recognition using genetic algorithm.

    PubMed

    Bardsiri, Mahshid Khatibi; Eftekhari, Mahdi; Mousavi, Reza

    2015-01-01

    In this study the problem of protein fold recognition, that is a classification task, is solved via a hybrid of evolutionary algorithms namely multi-gene Genetic Programming (GP) and Genetic Algorithm (GA). Our proposed method consists of two main stages and is performed on three datasets taken from the literature. Each dataset contains different feature groups and classes. In the first step, multi-gene GP is used for producing binary classifiers based on various feature groups for each class. Then, different classifiers obtained for each class are combined via weighted voting so that the weights are determined through GA. At the end of the first step, there is a separate binary classifier for each class. In the second stage, the obtained binary classifiers are combined via GA weighting in order to generate the overall classifier. The final obtained classifier is superior to the previous works found in the literature in terms of classification accuracy. PMID:25786796

  6. Design and implementation of high dynamic GNSS digital receiver

    NASA Astrophysics Data System (ADS)

    Li, Hanmei; Geng, Shengqun; Wang, Ce; Xu, Yong; Zhang, Qishan

    2007-11-01

    The paper presents a scheme of high dynamic GNSS digital receiver using FPGA xc4vsx55 of XILINX and DSP TMS320VC6701 of TI as core controller. Besides brief introduction of scheme design and hardware structure, the paper comprehensively introduces design and implementation of algorithms of fast acquisition and tracking of spread spectrum signal in high dynamic environment. Through optimized design, fast acquisition and tracking of both C code (coarse ranging code) and P code (precision ranging code) are realized in one chip of FPGA, under the control of DSP. Employing FFT-based fast acquisition algorithm, acquisition unit realizes the fast acquisition by duplicated using two FFT/IFFT units with time-sharing fashion, and other optimized FFT calculation structures. Carrier tracking loop is realized by adopting FLL+PLL method which using FLL tracking carrier Doppler shift with greater bandwidth making loop closed rapidly and using PLL precisely tracking carrier phase so as to achieve perfect tracking effects. PN code tracking loop is realized by using multiple non-coherent DLLs with various correlation spacing, which satisfying the requirements of larger tracking range as well as higher tracking precision by using broad spacing accomplishing initial tracking and narrow spacing realizing high precision tracking.

  7. A multi-gene transcriptional profiling approach to the discovery of cell signature markers

    PubMed Central

    Wada, Youichiro; Li, Dan; Merley, Anne; Zukauskas, Andrew; Aird, William C.; Dvorak, Harold F.

    2010-01-01

    A profile of transcript abundances from multiple genes constitutes a molecular signature if the expression pattern is unique to one cell type. Here we measure mRNA copy numbers per cell by normalizing per million copies of 18S rRNA and identify 6 genes (TIE1, KDR, CDH5, TIE2, EFNA1 and MYO5C) out of 79 genes tested as excellent molecular signature markers for endothelial cells (ECs) in vitro. The selected genes are uniformly expressed in ECs of 4 different origins but weakly or not expressed in 4 non-EC cell lines. A multi-gene transcriptional profile of these 6 genes clearly distinguishes ECs from non-ECs in vitro. We conclude that (i) a profile of mRNA copy numbers per cell from a well-chosen multi-gene panel can act as a sensitive and accurate cell type signature marker, and (ii) the method described here can be applied to in vivo cell fingerprinting and molecular diagnosis. PMID:20972619

  8. A multi-gene transcriptional profiling approach to the discovery of cell signature markers.

    PubMed

    Wada, Youichiro; Li, Dan; Merley, Anne; Zukauskas, Andrew; Aird, William C; Dvorak, Harold F; Shih, Shou-Ching

    2011-01-01

    A profile of transcript abundances from multiple genes constitutes a molecular signature if the expression pattern is unique to one cell type. Here we measure mRNA copy numbers per cell by normalizing per million copies of 18S rRNA and identify 6 genes (TIE1, KDR, CDH5, TIE2, EFNA1 and MYO5C) out of 79 genes tested as excellent molecular signature markers for endothelial cells (ECs) in vitro. The selected genes are uniformly expressed in ECs of 4 different origins but weakly or not expressed in 4 non-EC cell lines. A multi-gene transcriptional profile of these 6 genes clearly distinguishes ECs from non-ECs in vitro. We conclude that (i) a profile of mRNA copy numbers per cell from a well-chosen multi-gene panel can act as a sensitive and accurate cell type signature marker, and (ii) the method described here can be applied to in vivo cell fingerprinting and molecular diagnosis. PMID:20972619

  9. A molecular phylogeny of Zamia L.: a multi-gene approach using single-copy nuclear genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Zamia, with approximately 70 species, is the most morphologically and ecologically diverse genus in the Cycadales. We present the preliminary results of a multi-gene phylogenetic analysis of the genus Zamia including over 90% of the currently accepted species in the genus. A concatenated ...

  10. Multi-gene analysis of Symbiodinium dinoflagellates: a perspective on rarity, symbiosis, and evolution

    PubMed Central

    Putnam, Hollie M.; Gates, Ruth D.

    2014-01-01

    Symbiodinium, a large group of dinoflagellates, live in symbiosis with marine protists, invertebrate metazoans, and free-living in the environment. Symbiodinium are functionally variable and play critical energetic roles in symbiosis. Our knowledge of Symbiodinium has been historically constrained by the limited number of molecular markers available to study evolution in the genus. Here we compare six functional genes, representing three cellular compartments, in the nine known Symbiodinium lineages. Despite striking similarities among the single gene phylogenies from distinct organelles, none were evolutionarily identical. A fully concatenated reconstruction, however, yielded a well-resolved topology identical to the current benchmark nr28S gene. Evolutionary rates differed among cellular compartments and clades, a pattern largely driven by higher rates of evolution in the chloroplast genes of Symbiodinium clades D2 and I. The rapid rates of evolution observed amongst these relatively uncommon Symbiodinium lineages in the functionally critical chloroplast may translate into potential innovation for the symbiosis. The multi-gene analysis highlights the potential power of assessing genome-wide evolutionary patterns using recent advances in sequencing technology and emphasizes the importance of integrating ecological data with more comprehensive sampling of free-living and symbiotic Symbiodinium in assessing the evolutionary adaptation of this enigmatic dinoflagellate. PMID:24883254

  11. High dynamic global positioning system receiver

    NASA Technical Reports Server (NTRS)

    Hurd, W. J. (Inventor)

    1986-01-01

    A Global Positioning System (GPS) receiver having a number of channels, receives an aggregate of pseudorange code time division modulated signals. The aggregate is converted to baseband and then to digital form for separate processing in the separate channels. A fast fourier transform processor computes the signal energy as a function of Doppler frequency for each correlation lag, and a range and frequency estimator computes estimates of pseudorange, and frequency. Raw estimates from all channels are used to estimate receiver position, velocity, clock offset and clock rate offset in a conventional navigation and control unit, and based on the unit that computes smoothed estimates for the next measurement interval.

  12. New Highly Dynamic Approach for Thrust Vector Control

    NASA Astrophysics Data System (ADS)

    Hecht, M.; Ettl, J.; Grothe, D.; Hrbud, I.

    2015-09-01

    For a new launcher system a thrust vector control system is needed. This launch vehicle system consists of two rockets which are namely the VS-50 (two-stage suborbital vehicle) and the VLM-1 (three-stage microsatellite launch vehicle). VLM-1 and VS-50 are developed in a cooperation between the German Aerospace Center (DLR) and the Brazilian Aeronautics and Space Institute (IAE). To keep these two rockets on its trajectory during flight a highly dynamic thrust vector control system is required. For the purpose of developing such a highly dynamic thrust vector control system a master thesis was written by the author. The development includes all mechanical constructions as well as control algorithms and electronics design. Moreover an optimization of control algorithms was made to increase the dynamic capabilities of the thrust vector control system. The composition of the right components plus the sophisticated control algorithm make the thrust vector control system highly dynamic.

  13. Enhanced production of shikimic acid using a multi-gene co-expression system in Escherichia coli.

    PubMed

    Liu, Xiang-Lei; Lin, Jun; Hu, Hai-Feng; Zhou, Bin; Zhu, Bao-Quan

    2016-04-01

    Shikimic acid (SA) is the key synthetic material for the chemical synthesis of Oseltamivir, which is prescribed as the front-line treatment for serious cases of influenza. Multi-gene expression vector can be used for expressing the plurality of the genes in one plasmid, so it is widely applied to increase the yield of metabolites. In the present study, on the basis of a shikimate kinase genetic defect strain Escherichia coli BL21 (ΔaroL/aroK, DE3), the key enzyme genes aroG, aroB, tktA and aroE of SA pathway were co-expressed and compared systematically by constructing a series of multi-gene expression vectors. The results showed that different gene co-expression combinations (two, three or four genes) or gene orders had different effects on the production of SA. SA production of the recombinant BL21-GBAE reached to 886.38 mg·L(-1), which was 17-fold (P < 0.05) of the parent strain BL21 (ΔaroL/aroK, DE3). PMID:27114316

  14. Iterative methods for the reconstruction of astronomical images with high dynamic range

    NASA Astrophysics Data System (ADS)

    Anconelli, B.; Bertero, M.; Boccacci, P.; Carbillet, M.; Lanteri, H.

    2007-01-01

    In most cases astronomical images contain objects with very different intensities such as bright stars combined with faint nebulae. Since the noise is mainly due to photon counting (Poisson noise), the signal-to-noise ratio may be very different in different regions of the image. Moreover, the bright and faint objects have, in general, different angular scales. These features imply that the iterative methods which are most frequently used for the reconstruction of astronomical images, namely the Richardson-Lucy Method (RLM), also known in tomography as Expectation Maximization (EM) method, and the Iterative Space Reconstruction Algorithm (ISRA) do not work well in these cases. Also standard regularization approaches do not provide satisfactory results since a kind of adaptive regularization is required, in the sense that one needs a different regularization for bright and faint objects. In this paper we analyze a number of regularization functionals with this particular kind of adaptivity and we propose a simple modification of RLM and ISRA which takes into account these regularization terms. The preliminary results on a test object are promising.

  15. High dynamic range temperature-compensated fibre Bragg gratings sensor for structural monitoring of buildings

    NASA Astrophysics Data System (ADS)

    Smeu, E.; Gnewuch, H.; Jackson, D. A.; Podoleanu, A.

    2006-06-01

    The distance changes between structural elements inside a building (e.g. walls, pillars, stairs, etc.) ought to be monitored, especially in seismic-prone areas, in order to assess its stability. Fibre Bragg grating (FBG) sensors are now the most interesting choice for this purpose, since several gratings can be included in the fibre, resulting in a quasi-distributed sensor, which can be illuminated using a single light source and interrogated simply by a single optical spectrum analyzer (OSA), using wavelength multiplexing. The paper deals with such a sensor, which was installed for monitoring the distance changes in a construction joint between two building blocks inside the University "Politehnica" of Bucharest. Since this city is placed in a seismic-prone area, we use a fast scanning OSA, so that the dynamic behavior of the monitored construction joint is expected to be captured during future earthquakes. Slow drifts of the construction joint width will be also monitored. The paper describes the sensor structure and working principle, the experimental tests and main parameters evaluation. The reported sensor is temperature compensated. It has an estimated distance resolution better or equal to 10 μm, and a linearity of +0.2%...-0.35% for displacements up to 0.55 mm. Simulated dynamic tests are also reported.

  16. Exposure fusion based on steerable pyramid for displaying high dynamic range scenes

    NASA Astrophysics Data System (ADS)

    Wang, Jinhua; Xu, De; Li, Bing

    2009-11-01

    Currently, most exposure fusion algorithms are put forward on the assumption that the source images are aligned prior to fusion. As a result, some artifacts, such as haloing, may be caused due to the slight misalignment in the source images. In order to reduce the influence induced by the misalignment, a novel shift-invariant and rotation-invariant steerable pyramid-based exposure fusion (SPBEF) algorithm is proposed. It can combine multiple color images of a scene with different exposures to one image with high quality. First, instead of processing of R, G, and B channels separately, the chrominance information of the scene is obtained by the average image of the median two images. The strategy can greatly reduce the computational complexity. Second, the luminance images of source images are then transferred to frequency domain and are fused to one luminance image using different fusion rules in different frequencies. In this process, fusion is performed in a hierarchical fashion. Last, the final color image is generated by combining the data of the fused luminance image and the chrominance information. Experiments show that SPBEF can give comparative or even better results compared to other exposure fusion algorithms, as well as other traditional pyramid-based fusion algorithms

  17. Power supply with air core transformer and seperated power supplies for high dynamic range

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Aalami, Dean (Inventor); Darrach, Murray (Inventor); Orient, Otto (Inventor)

    2001-01-01

    A power supply for a quadrupole mass spectrometer which operates using an RF signal. The RF signal is controllable via a feedback loop. The feedback loop is from the output, through a comparator, and compared to a digital signal. An air core transformer is used to minimize the weight. The air core transformer is driven via two out of phase sawtooth signals which drive opposite ends of the transformer.

  18. High Dynamic Range VLA Observations of the Gravitationally Lensed Quasar 0957+561

    NASA Astrophysics Data System (ADS)

    Harvanek, Michael; Stocke, John T.; Morse, Jon A.; Rhee, George

    1997-12-01

    We present 2, 3.6, 6, and 20 cm radio maps of the gravitationally leased quasar 0957+561 obtained with the VLA in A configuration. Besides the well-known jet and lobe structure associated with image A and the point sources associated with image B and the radio source G, the new 3.6 cm maps show interesting extensions of radio source G towards and away from B and the 20 cm map shows a large amount of extended structure, some of it not seen before. We argue that at least some of the 3.6 cm extensions of G are the radio jet associated with image B placing the caustic for multiple images outside the radio jet emitting region. The central portion of the extended 20 cm emission may be an "Einstein ring" produced by faint radio emission located at the caustic while the northern and southern portions of the extended 20 cm emission resemble the outer lobes of a faint "classical double" source with an axis nearly perpendicular to the axis of the jet and lobe emission associated with image A. If these outer "lobes" are second images of the lobes associated with image A then they are very difficult to understand theoretically. Most likely they are the radio lobes of the galaxy G1. Relative point source positions are presented and compared to published VLBI positions and recently obtained optical positions from HST confirming that the VLA source G is coincident (±0.02") with both the VLBI source G' and the nucleus of the leasing galaxy G 1. However, all or a portion of radio source G/G' may still be the elusive third image of the quasar rather than a radio source associated with galaxy G1. Fluxes, spectral indices and flux ratios are presented and compared to values found in the literature. A portion of the 20 cm extended emission occurs in a region where extended X-ray emission was reported to be detected by Einstein and ROSAT. However, a re-analysis of the ROSAT data shows little evidence for this emission.

  19. High dynamic range diamond detector acquisition system for beam wire scanner applications

    NASA Astrophysics Data System (ADS)

    Sirvent, J. L.; Dehning, B.; Piselli, E.; Emery, J.; Dieguez, A.

    2016-03-01

    The CERN Beam Instrumentation group has been working during the last years on the beam wire scanners upgrade to cope up with the increasing requirements of CERN experiments. These devices are used to measure the beam profile by crossing a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected and correlated with the wire position to reconstruct the beam profile. The upgraded secondary particles acquisition electronics will use polycrystalline chemical vapour deposition (pCVD) diamond detectors for particle shower measurements, with low noise acquisitions performed on the tunnel, near the detector. The digital data is transmitted to the surface through an optical link with the GBT protocol. Two integrator ASICs (ICECAL and QIE10) are being characterized and compared for detector readout with the complete acquisition chain prototype. This contribution presents the project status, the QIE10 front-end performance and the first measurements with the complete acquisition system prototype. In addition, diamond detector signals from particle showers generated by an operational beam wire scanner are analysed and compared with an operational system.

  20. Brightness, lightness, and specifying color in high-dynamic-range scenes and images

    NASA Astrophysics Data System (ADS)

    Fairchild, Mark D.; Chen, Ping-Hsu

    2011-01-01

    Traditional color spaces have been widely used in a variety of applications including digital color imaging, color image quality, and color management. These spaces, however, were designed for the domain of color stimuli typically encountered with reflecting objects and image displays of such objects. This means the domain of stimuli with luminance levels from slightly above zero to that of a perfect diffuse white (or display white point). This limits the applicability of such spaces to color problems in HDR imaging. This is caused by their hard intercepts at zero luminance/lightness and by their uncertain applicability for colors brighter than diffuse white. To address HDR applications, two new color spaces were recently proposed, hdr-CIELAB and hdr-IPT. They are based on replacing the power-function nonlinearities in CIELAB and IPT with more physiologically plausible hyperbolic functions optimized to most closely simulate the original color spaces in the diffuse reflecting color domain. This paper presents the formulation of the new models, evaluations using Munsell data in comparison with CIELAB, IPT, and CIECAM02, two sets of lightness-scaling data above diffuse white, and various possible formulations of hdr-CIELAB and hdr-IPT to predict the visual results.

  1. Human C3b- and C4b-regulatory proteins: a new multi-gene family.

    PubMed

    Holers, V M; Cole, J L; Lublin, D M; Seya, T; Atkinson, J P

    1985-06-01

    The complement cascade is regulated to prevent inappropriate activation. This regulation is targeted not only at the initiation of the cascade but also at the amplification andjunctional (C3) steps. Five glycoproteins with both complement regulatory activity and binding affinity for C3b/C4b have been characterized. In plasma these molecules are factor H(H) and C4-binding protein (C4-bp) and, on cells, they are the C3b/C4b receptor (CR1), decay-accelerating factor (DAF), and gp45-70. Here Michael Holers and his colleagues review structural, functional and genetic studies of these proteins and discuss the evidence for a new multi-gene family with a common ancestral protein. PMID:25289982

  2. Exposure Time Optimization for Highly Dynamic Star Trackers

    PubMed Central

    Wei, Xinguo; Tan, Wei; Li, Jian; Zhang, Guangjun

    2014-01-01

    Under highly dynamic conditions, the star-spots on the image sensor of a star tracker move across many pixels during the exposure time, which will reduce star detection sensitivity and increase star location errors. However, this kind of effect can be compensated well by setting an appropriate exposure time. This paper focuses on how exposure time affects the star tracker under highly dynamic conditions and how to determine the most appropriate exposure time for this case. Firstly, the effect of exposure time on star detection sensitivity is analyzed by establishing the dynamic star-spot imaging model. Then the star location error is deduced based on the error analysis of the sub-pixel centroiding algorithm. Combining these analyses, the effect of exposure time on attitude accuracy is finally determined. Some simulations are carried out to validate these effects, and the results show that there are different optimal exposure times for different angular velocities of a star tracker with a given configuration. In addition, the results of night sky experiments using a real star tracker agree with the simulation results. The summarized regularities in this paper should prove helpful in the system design and dynamic performance evaluation of the highly dynamic star trackers. PMID:24618776

  3. Exposure time optimization for highly dynamic star trackers.

    PubMed

    Wei, Xinguo; Tan, Wei; Li, Jian; Zhang, Guangjun

    2014-01-01

    Under highly dynamic conditions, the star-spots on the image sensor of a star tracker move across many pixels during the exposure time, which will reduce star detection sensitivity and increase star location errors. However, this kind of effect can be compensated well by setting an appropriate exposure time. This paper focuses on how exposure time affects the star tracker under highly dynamic conditions and how to determine the most appropriate exposure time for this case. Firstly, the effect of exposure time on star detection sensitivity is analyzed by establishing the dynamic star-spot imaging model. Then the star location error is deduced based on the error analysis of the sub-pixel centroiding algorithm. Combining these analyses, the effect of exposure time on attitude accuracy is finally determined. Some simulations are carried out to validate these effects, and the results show that there are different optimal exposure times for different angular velocities of a star tracker with a given configuration. In addition, the results of night sky experiments using a real star tracker agree with the simulation results. The summarized regularities in this paper should prove helpful in the system design and dynamic performance evaluation of the highly dynamic star trackers. PMID:24618776

  4. 2A self-cleaving peptide-based multi-gene expression system in the silkworm Bombyx mori

    PubMed Central

    Wang, Yuancheng; Wang, Feng; Wang, Riyuan; Zhao, Ping; Xia, Qingyou

    2015-01-01

    Fundamental and applied studies of silkworms have entered the functional genomics era. Here, we report a multi-gene expression system (MGES) based on 2A self-cleaving peptide (2A), which regulates the simultaneous expression and cleavage of multiple gene targets in the silk gland of transgenic silkworms. First, a glycine-serine-glycine spacer (GSG) was found to significantly improve the cleavage efficiency of 2A. Then, the cleavage efficiency of six types of 2As with GSG was analyzed. The shortest porcine teschovirus-1 2A (P2A-GSG) exhibited the highest cleavage efficiency in all insect cell lines that we tested. Next, P2A-GSG successfully cleaved the artificial human serum albumin (66 kDa) linked with human acidic fibroblast growth factor (20.2 kDa) fusion genes and vitellogenin receptor fragment (196 kD) of silkworm linked with EGFP fusion genes, importantly, vitellogenin receptor protein was secreted to the outside of cells. Furthermore, P2A-GSG successfully mediated the simultaneous expression and cleavage of a DsRed and EGFP fusion gene in silk glands and caused secretion into the cocoon of transgenic silkworms using our sericin1 expression system. We predicted that the MGES would be an efficient tool for gene function research and innovative research on various functional silk materials in medicine, cosmetics, and other biomedical areas. PMID:26537835

  5. A Systematic Evaluation of Multi-Gene Predictors for the Pathological Response of Breast Cancer Patients to Chemotherapy

    PubMed Central

    Kim, Youngchul; Tian, Chunqiao; Rice, Shara D.; Gabrin, Michael J.; Symmans, W. Fraser; Pusztai, Lajos; Lee, Jae K.

    2012-01-01

    Previous studies have reported conflicting assessments of the ability of cell line-derived multi-gene predictors (MGPs) to forecast patient clinical outcomes in cancer patients, thereby warranting an investigation into their suitability for this task. Here, 42 breast cancer cell lines were evaluated by chemoresponse tests after treatment with either TFAC or FEC, two widely used standard combination chemotherapies for breast cancer. We used two different training cell line sets and two independent prediction methods, superPC and COXEN, to develop cell line-based MGPs, which were then validated in five patient cohorts treated with these chemotherapies. This evaluation yielded high prediction performances by these MGPs, regardless of the training set, chemotherapy, or prediction method. The MGPs were also able to predict patient clinical outcomes for the subgroup of estrogen receptor (ER)-negative patients, which has proven difficult in the past. These results demonstrated a potential of using an in vitro-based chemoresponse data as a model system in creating MGPs for stratifying patients’ therapeutic responses. Clinical utility and applications of these MGPs will need to be carefully examined with relevant clinical outcome measurements and constraints in practical use. PMID:23185353

  6. A multi-gene approach reveals a complex evolutionary history in the Cyanistes species group.

    PubMed

    Illera, Juan Carlos; Koivula, Kari; Broggi, Juli; Päckert, Martin; Martens, Jochen; Kvist, Laura

    2011-10-01

    Quaternary climatic oscillations have been considered decisive in shaping much of the phylogeographic structure around the Mediterranean Basin. Within this paradigm, peripheral islands are usually considered as the endpoints of the colonization processes. Here, we use nuclear and mitochondrial markers to investigate the phylogeography of the blue tit complex (blue tit Cyanistes caeruleus, Canary blue tit C. teneriffae and azure tit C. cyanus), and assess the role of the Canary Islands for the geographic structuring of genetic variation. The Canary blue tit exhibits strong genetic differentiation within the Canary Islands and, in combination with other related continental species, provides an ideal model in which to examine recent differentiation within a closely related group of continental and oceanic island avian species. We analysed DNA sequences from 51 breeding populations and more than 400 individuals in the blue tit complex. Discrepancies in the nuclear and mitochondrial gene trees provided evidence of a complex evolutionary process around the Mediterranean Basin. Coalescent analyses revealed gene flow between C. caeruleus and C. teneriffae suggesting a dynamic process with multiple phases of colonization and geographic overlapping ranges. Microsatellite data indicated strong genetic differentiation among the Canary Islands and between the Canary archipelago and the close continental areas, indicating limited contemporary gene flow. Diversification of the blue tit complex is estimated to have started during the early Pliocene (≈ 5 Ma), coincident with the end of Messinian salinity crisis. Phylogenetic analyses indicated that the North African blue tit is derived from the Canary blue tits, a pattern is avian 'back colonization' that contrasts with more traditionally held views of islands being sinks rather than sources. PMID:21880092

  7. Increased yield of actionable mutations using multi-gene panels to assess hereditary cancer susceptibility in an ethnically diverse clinical cohort.

    PubMed

    Ricker, Charité; Culver, Julie O; Lowstuter, Katrina; Sturgeon, Duveen; Sturgeon, Julia D; Chanock, Christopher R; Gauderman, William J; McDonnell, Kevin J; Idos, Gregory E; Gruber, Stephen B

    2016-04-01

    This study aims to assess multi-gene panel testing in an ethnically diverse clinical cancer genetics practice. We conducted a retrospective study of individuals with a personal or family history of cancer undergoing clinically indicated multi-gene panel tests of 6-110 genes, from six commercial laboratories. The 475 patients in the study included 228 Hispanics (47.6%), 166 non-Hispanic Whites (35.4%), 55 Asians (11.6%), 19 Blacks (4.0%), and seven others (1.5%). Panel testing found that 15.6% (74/475) of patients carried deleterious mutations for a total of 79 mutations identified. This included 7.4% (35/475) of patients who had a mutation identified that would not have been tested with a gene-by-gene approach. The identification of a panel-added mutation impacted clinical management for most of cases (69%, 24/35), and genetic testing was recommended for the first degree relatives of nearly all of them (91%, 32/35). Variants of uncertain significance (VUSs) were identified in a higher proportion of tests performed in ethnic minorities. Multi-gene panel testing increases the yield of mutations detected and adds to the capability of providing individualized cancer risk assessment. VUSs represent an interpretive challenge due to less data available outside of White, non-Hispanic populations. Further studies are necessary to expand understanding of the implementation and utilization of panels across broad clinical settings and patient populations. PMID:26908360

  8. Molecular phylogenetics of eimeriid coccidia (Eimeriidae, Eimeriorina, Apicomplexa, Alveolata): A preliminary multi-gene and multi-genome approach.

    PubMed

    Ogedengbe, Joseph D; Ogedengbe, Mosun E; Hafeez, Mian A; Barta, John R

    2015-11-01

    Coccidia possess three distinct genomes: nuclear, mitochondrial, and plastid. Sequences from five genes located on these three genomes were used to reconstruct the phylogenetic relationships of members of the phylum Apicomplexa: 18S rDNA sequences from the nuclear (nu) genome, partial cytochrome c oxidase subunit I sequences from the mitochondrial (mt) genome, and partial 16S and 23S rDNA sequences and RNA polymerase B sequences from plastid (pl) genomes. Maximum parsimony, maximum likelihood, and Bayesian inference were used in conjunction with nuclear substitution models generated from data subsets in the analyses. Major groups within the Apicomplexa were well supported with the mitochondrial, nuclear, and a combination of mitochondrial, nuclear and concatenated plastid gene sequences. However, the genus Eimeria was paraphyletic in phylogenetic trees based on the nuclear gene. Analyses using the individual genes (18S rDNA and cytochrome c oxidase subunit I) resolved the various apicomplexan groups with high Bayesian posterior probabilities. The multi-gene, multi-genome analyses based on concatenated nu 18S rDNA, pl 16S, pl 23S, pl rPoB, pl rPoB1, and mt COI sequences appeared useful in resolving phylogenetic relationships within the phylum Apicomplexa. Genus-level relationships, or higher, appear best supported by 18S rDNA analyses, and species-level analyses are best investigated using mt COI sequences; for parasites for which both loci are available, nuclear 18S rDNA sequences combined with mitochondrial COI sequences provide a compact and informative molecular dataset for inferring the evolutionary relationships taxa in the Apicomplexa. PMID:26319519

  9. Direct Detection and Differentiation of Pathogenic Leptospira Species Using a Multi-Gene Targeted Real Time PCR Approach

    PubMed Central

    Ferreira, Ana Sofia; Costa, Pedro; Rocha, Teresa; Amaro, Ana; Vieira, Maria Luísa; Ahmed, Ahmed; Thompson, Gertrude; Hartskeerl, Rudy A.; Inácio, João

    2014-01-01

    Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal β-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis. PMID:25398140

  10. Direct detection and differentiation of pathogenic Leptospira species using a multi-gene targeted real time PCR approach.

    PubMed

    Ferreira, Ana Sofia; Costa, Pedro; Rocha, Teresa; Amaro, Ana; Vieira, Maria Luísa; Ahmed, Ahmed; Thompson, Gertrude; Hartskeerl, Rudy A; Inácio, João

    2014-01-01

    Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal β-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis. PMID:25398140

  11. Multi-Gene Analysis Reveals a Lack of Genetic Divergence between Calanus agulhensis and C. sinicus (Copepoda; Calanoida)

    PubMed Central

    Kozol, Robert; Blanco-Bercial, Leocadio; Bucklin, Ann

    2012-01-01

    The discrimination and taxonomic identification of marine species continues to pose a challenge despite the growing number of diagnostic metrics and approaches. This study examined the genetic relationship between two sibling species of the genus Calanus (Crustacea; Copepoda; Calanidae), C. agulhensis and C. sinicus, using a multi-gene analysis. DNA sequences were determined for portions of the mitochondrial cytochrome c oxidase I (mtCOI); nuclear citrate synthase (CS), and large subunit (28S) rRNA genes for specimens collected from the Sea of Japan and North East (NE) Pacific Ocean for C. sinicus and from the Benguela Current and Agulhas Bank, off South Africa, for C. agulhensis. For mtCOI, C. sinicus and C. agulhensis showed similar levels of haplotype diversity (Hd = 0.695 and 0.660, respectively) and nucleotide diversity (π = 0.003 and 0.002, respectively). Pairwise FST distances for mtCOI were significant only between C. agulhensis collected from the Agulhas and two C. sinicus populations: the Sea of Japan (FST = 0.152, p<0.01) and NE Pacific (FST = 0.228, p<0.005). Between the species, FST distances were low for both mtCOI (FST = 0.083, p = 0.003) and CS (FST = 0.050, p = 0.021). Large subunit (28S) rRNA showed no variation between the species. Our results provide evidence of the lack of genetic distinction of C. sinicus and C. agulhensis, raise questions of whether C. agulhensis warrants status as a distinct species, and indicate the clear need for more intensive and extensive ecological and genetic analysis. PMID:23118849

  12. Impact of the Multi-Gene ThyroSeq Next-Generation Sequencing Assay on Cancer Diagnosis in Thyroid Nodules with Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance Cytology

    PubMed Central

    Carty, Sally E.; Chiosea, Simon I.; Coyne, Christopher; Duvvuri, Umamaheswar; Ferris, Robert L.; Gooding, William E.; LeBeau, Shane O.; Ohori, N. Paul; Seethala, Raja R.; Tublin, Mitchell E.; Yip, Linwah; Nikiforova, Marina N.

    2015-01-01

    Background: Fine-needle aspiration (FNA) cytology is a common approach to evaluate thyroid nodules. It offers definitive diagnosis of a benign or malignant nodule in the majority of cases. However, 10–25% of nodules yield one of three indeterminate cytologic diagnoses, leading to suboptimal management of these patients. Atypia of undetermined significance/follicular lesion of undermined significance (AUS/FLUS) is a common indeterminate diagnosis, with the cancer risk ranging from 6% to 48%. This study assessed whether a multi-gene next-generation sequencing (NGS) assay can offer significant improvement in diagnosis in AUS/FLUS nodules. Methods: From May 2014 to March 2015, 465 consecutive FNA samples with the cytologic diagnosis of AUS/FLUS underwent prospective molecular testing using the ThyroSeq v2.1 panel. The panel included 14 genes analyzed for point mutations and 42 types of gene fusions occurring in thyroid cancer. In addition, eight genes were assessed for expression in order to evaluate the cell composition of FNA samples. Ninety-eight (21%) of these nodules had definitive surgical (n = 96) or nonsurgical (n = 2) follow-up and were used to determine the assay performance. Results: Among 465 AUS/FLUS nodules, three were found to be composed of parathyroid cells and 462 of thyroid follicular cells. Of the latter, 31 (6.7%) were positive for mutations. The most frequently mutated genes were NRAS and HRAS, and overall point mutations in seven different genes and five types of gene fusions were identified in these nodules. Among 98 nodules with known outcome, histologic analysis revealed 22 (22.5%) cancers. ThyroSeq v2.1 was able to classify 20/22 cancers correctly, showing a sensitivity of 90.9% [confidence interval (CI) 78.8–100], specificity of 92.1% [CI 86.0–98.2], positive predictive value of 76.9% [CI 60.7–93.1], and negative predictive value of 97.2% [CI 78.8–100], with an overall accuracy of 91.8% [CI 86.4–97.3]. Conclusions: The

  13. Xyloglucan endotransglycosylase/hydrolase (XTH) is encoded by a multi-gene family in the primitive vascular land plant Selaginella kraussiana.

    PubMed

    Van Sandt, V S T; Guisez, Y; Verbelen, J-P; Vissenberg, K

    2007-01-01

    Xyloglucan endotransglycosylase/hydrolases (XTHs) are enzymes that cleave and rejoin xyloglucan chains. To trace the evolutionary origin of XTHs, we used Selaginella kraussiana, a representative of the most primitive land plants (Lycopodiophyta). A Southern blot with a digoxigenin-labeled probe, designed on the conserved catalytic site of XTHs, indicated nine genes. The presence of at least seven functional XTHs was detected by isoelectric focusing (IEF) followed by overlaying the gel with a XET-test paper. Together, these results indicate that XTHs are encoded by a multi-gene family that originated during or even before the colonization of land by plants. PMID:17099842

  14. Detection of high frequency of mutations in a breast and/or ovarian cancer cohort: implications of embracing a multi-gene panel in molecular diagnosis in India.

    PubMed

    Mannan, Ashraf U; Singh, Jaya; Lakshmikeshava, Ravikiran; Thota, Nishita; Singh, Suhasini; Sowmya, T S; Mishra, Avshesh; Sinha, Aditi; Deshwal, Shivani; Soni, Megha R; Chandrasekar, Anbukayalvizhi; Ramesh, Bhargavi; Ramamurthy, Bharat; Padhi, Shila; Manek, Payal; Ramalingam, Ravi; Kapoor, Suman; Ghosh, Mithua; Sankaran, Satish; Ghosh, Arunabha; Veeramachaneni, Vamsi; Ramamoorthy, Preveen; Hariharan, Ramesh; Subramanian, Kalyanasundaram

    2016-06-01

    Breast and/or ovarian cancer (BOC) are among the most frequently diagnosed forms of hereditary cancers and leading cause of death in India. This emphasizes on the need for a cost-effective method for early detection of these cancers. We sequenced 141 unrelated patients and families with BOC using the TruSight Cancer panel, which includes 13 genes strongly associated with risk of inherited BOC. Multi-gene sequencing was done on the Illumina MiSeq platform. Genetic variations were identified using the Strand NGS software and interpreted using the StrandOmics platform. We were able to detect pathogenic mutations in 51 (36.2%) cases, out of which 19 were novel mutations. When we considered familial breast cancer cases only, the detection rate increased to 52%. When cases were stratified based on age of diagnosis into three categories, ⩽40 years, 40-50 years and >50 years, the detection rates were higher in the first two categories (44.4% and 53.4%, respectively) as compared with the third category, in which it was 26.9%. Our study suggests that next-generation sequencing-based multi-gene panels increase the sensitivity of mutation detection and help in identifying patients with a high risk of developing cancer as compared with sequential tests of individual genes. PMID:26911350

  15. Space-Based Range Safety and Future Space Range Applications

    NASA Technical Reports Server (NTRS)

    Whiteman, Donald E.; Valencia, Lisa M.; Simpson, James C.

    2005-01-01

    The National Aeronautics and Space Administration (NASA) Space-Based Telemetry and Range Safety (STARS) study is a multiphase project to demonstrate the performance, flexibility and cost savings that can be realized by using space-based assets for the Range Safety [global positioning system (GPS) metric tracking data, flight termination command and range safety data relay] and Range User (telemetry) functions during vehicle launches and landings. Phase 1 included flight testing S-band Range Safety and Range User hardware in 2003 onboard a high-dynamic aircraft platform at Dryden Flight Research Center (Edwards, California, USA) using the NASA Tracking and Data Relay Satellite System (TDRSS) as the communications link. The current effort, Phase 2, includes hardware and packaging upgrades to the S-band Range Safety system and development of a high data rate Ku-band Range User system. The enhanced Phase 2 Range Safety Unit (RSU) provided real-time video for three days during the historic Global Flyer (Scaled Composites, Mojave, California, USA) flight in March, 2005. Additional Phase 2 testing will include a sounding rocket test of the Range Safety system and aircraft flight testing of both systems. Future testing will include a flight test on a launch vehicle platform. This paper discusses both Range Safety and Range User developments and testing with emphasis on the Range Safety system. The operational concept of a future space-based range is also discussed.

  16. Space-Based Range Safety and Future Space Range Applications

    NASA Technical Reports Server (NTRS)

    Whiteman, Donald E.; Valencia, Lisa M.; Simpson, James C.

    2005-01-01

    The National Aeronautics and Space Administration Space-Based Telemetry and Range Safety study is a multiphase project to demonstrate the performance, flexibility and cost savings that can be realized by using space-based assets for the Range Safety (global positioning system metric tracking data, flight termination command and range safety data relay) and Range User (telemetry) functions during vehicle launches and landings. Phase 1 included flight testing S-band Range Safety and Range User hardware in 2003 onboard a high-dynamic aircraft platform at Dryden Flight Research Center (Edwards, California) using the NASA Tracking and Data Relay Satellite System as the communications link. The current effort, Phase 2, includes hardware and packaging upgrades to the S-band Range Safety system and development of a high data rate Ku-band Range User system. The enhanced Phase 2 Range Safety Unit provided real-time video for three days during the historic GlobalFlyer (Scaled Composites, Mojave, California) flight in March, 2005. Additional Phase 2 testing will include a sounding rocket test of the Range Safety system and aircraft flight testing of both systems. Future testing will include a flight test on a launch vehicle platform. This report discusses both Range Safety and Range User developments and testing with emphasis on the Range Safety system. The operational concept of a future space-based range is also discussed.

  17. Wavelength-Modulated Differential Photoacoustic (WM-DPA) imaging: a high dynamic range modality towards noninvasive diagnosis of cancer

    NASA Astrophysics Data System (ADS)

    Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

    2016-03-01

    This study explores wavelength-modulated differential photo-acoustic (WM-DPA) imaging for non-invasive early cancer detection via sensitive characterization of functional information such as hemoglobin oxygenation (sO2) levels. Well-known benchmarks of tumor formation such as angiogenesis and hypoxia can be addressed this way. While most conventional photo-acoustic imaging has almost entirely employed high-power pulsed lasers, frequency-domain photo-acoustic radar (FD-PAR) has seen significant development as an alternative technique. It employs a continuous wave laser source intensity-modulated and driven by frequency-swept waveforms. WM-DPA imaging utilizes chirp modulated laser beams at two distinct wavelengths for which absorption differences between oxy- and deoxygenated hemoglobin are minimum (isosbestic point, 805 nm) and maximum (680 nm) to simultaneously generate two signals detected using a standard commercial array transducer as well as a single-element transducer that scans the sample. Signal processing is performed using Lab View and Matlab software developed in-house. Minute changes in total hemoglobin concentration (tHb) and oxygenation levels are detectable using this method since background absorption is suppressed due to the out-of-phase modulation of the laser sources while the difference between the two signals is amplified, thus allowing pre-malignant tumors to become identifiable. By regulating the signal amplitude ratio and phase shift the system can be tuned to applications like cancer screening, sO2 quantification and hypoxia monitoring in stroke patients. Experimental results presented demonstrate WM-DPA imaging of sheep blood phantoms in comparison to single-wavelength FD-PAR imaging. Future work includes the functional PA imaging of small animals in vivo.

  18. First high dynamic range and high resolution images of the sky obtained with a diffractive Fresnel array telescope

    NASA Astrophysics Data System (ADS)

    Koechlin, Laurent; Rivet, Jean-Pierre; Deba, Paul; Serre, Denis; Raksasataya, Truswin; Gili, René; David, Jules

    2012-03-01

    This paper presents high contrast images of sky sources, obtained from the ground with a novel optical concept: Fresnel arrays. We demonstrate the efficiency of a small 20 cm prototype Fresnel array for making images with high brightness ratios, achieving contrasts up to 4 × 105 on sky sources such as Mars and its satellites, and the Sirius A-B couple. These validation results are promising for future applications in space, for example the 4 m array we have proposed to ESA in the frame of the "Call for a Medium-size mission opportunity for a launch in 2022". Fresnel imagers are the subject of a topical issue of Experimental Astronomy published in 2011, but only preliminary results were presented at the time. Making images of astronomical bodies requires an optical component to focus light. This component is usually a mirror or a lens, the quality of which is critical for sharp and high contrast images. However, reflection on a mirror and refraction through a lens are not the only ways to focus light: an alternative is provided by diffraction through binary masks (opaque foils with multiple precisely etched sub-apertures). Our Fresnel arrays are such diffractive focusers, they offer weight, price and size advantages over traditional optics in space-based astronomical instruments. This novel approach requires only void apertures of special shapes in an opaque material to form sharp images, thus avoiding the wavefront distortion, diffusion and spectral absorption associated with traditional optical media. In our setup, lenses and/or mirrors are involved only downstream (at small sizes) for focal instrumentation and chromatic correction. Fresnel arrays produce high contrast images, the resolution of which reaches the theoretical limit of diffraction. Unlike mirrors, they do not require high precision polishing or positioning, and can be used in a large domain of wavelengths from far IR to far UV, enabling the study of many science cases in astrophysics from exoplanet surfaces and atmospheres to galaxy evolution.

  19. A low-noise high dynamic-range time-domain EMI measurement system for CISPR Band E

    NASA Astrophysics Data System (ADS)

    Hoffmann, C.; Russer, P.

    2011-08-01

    In this paper, a broadband time-domain EMI measurement system for measurements from 9 kHz to 18 GHz is presented that allows for compliant EMI measurements in CISPR Band E. Combining ultra-fast analog-to-digital-conversion and real-time digital signal processing on a field-programmable-gate-array (FPGA) with ultra-broadband multi-stage down-conversion, scan times can be reduced by several orders of magnitude in comparison to a traditional heterodyne EMI-receiver. The ultra-low system noise floor of 6-8 dB and the real-time spectrogram allow for the characterisation of the time-behaviour of EMI near the noise floor. EMI measurements of electronic consumer devices and electric household appliances are presented.

  20. Multi-gene phylogenetic analyses of New Zealand coralline algae: Corallinapetra Novaezelandiae gen. et sp. nov. and recognition of the Hapalidiales ord. nov.

    PubMed

    Nelson, Wendy A; Sutherland, Judith E; Farr, Tracy J; Hart, Darren R; Neill, Kate F; Kim, Hee Jeong; Yoon, Hwan Su

    2015-06-01

    Coralline red algae from the New Zealand region were investigated in a study focused on documenting regional diversity. We present a multi-gene analysis using sequence data obtained for four genes (nSSU, psaA, psbA, rbcL) from 68 samples. The study revealed cryptic diversity at both genus and species levels, confirming and providing further evidence of problems with current taxonomic concepts in the Corallinophycidae. In addition, a new genus Corallinapetra novaezelandiae gen. et sp. nov. is erected for material from northern New Zealand. Corallinapetra is excluded from all currently recognized families and orders within the Corallinophycidae and thus represents a previously unrecognized lineage within this subclass. We discuss rank in the Corallinophycidae and propose the order Hapalidiales. PMID:26986662

  1. High dynamic, spectral, and polarized natural light environment acquisition

    NASA Astrophysics Data System (ADS)

    Porral, Philippe; Callet, Patrick; Fuchs, Philippe; Muller, Thomas; Sandré-Chardonnal, Etienne

    2015-03-01

    In the field of image synthesis, the simulation of material's appearance requires a rigorous resolution of the light transport equation. This implies taking into account all the elements that may have an influence on the spectral radiance, and that are perceived by the human eye. Obviously, the reflectance properties of the materials have a major impact in the calculations, but other significant properties of light such as spectral distribution and polarization must also be taken into account, in order to expect correct results. Unfortunately real maps of the polarized or spectral environment corresponding to a real sky do not exist. Therefore, it seemed necessary to focus our work on capturing such data, in order to have a system that qualifies all the properties of light and capable of powering simulations in a renderer software. As a consequence, in this work, we develop and characterize a device designed to capture the entire light environment, by taking into account both the dynamic range of the spectral distribution and the polarization states, in a measurement time of less than two minutes. We propose a data format inspired by polarimetric imaging and fitted for a spectral rendering engine, which exploits the "Stokes-Mueller formalism."

  2. Range Ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After more than two hundred years, grazing remains California’s most extensive land use. The ‘Range Ecosystems’ chapter in the ‘Ecosystems of California’ sourcebook provides an integrated picture of the biophysical, social, and economic aspects of lands grazed by livestock in the state. Grazing mana...

  3. Kinematic Design and Ideal Dimensioning of New Highly Dynamic Drive Assemblies for Knitting and Braiding Machines

    NASA Astrophysics Data System (ADS)

    Denninger, D.; Berger, M.; Heine, A.

    The paper deals with the kinematic design and the ideal dimensioning of highly dynamic drive assemblies using MCAD strategies. The procedure is explained step by step by the example of a round braider construction. The analysis of the general mechanical principle and the definition of boundary conditions and objective criteria is our top priority. Innovative potential to increase performance and improve meshwork quality lies in the highly dynamic drive assembly to lay the threads. For a newly developed, non-linear mechanical drive concept, feasibility studies up to dimensional synthesis and draft analysis are demonstrated.

  4. A multi-gene dataset reveals a tropical New World origin and Early Miocene diversification of croakers (Perciformes: Sciaenidae).

    PubMed

    Lo, Pei-Chun; Liu, Shu-Hui; Chao, Ning Labbish; Nunoo, Francis K E; Mok, Hin-Kiu; Chen, Wei-Jen

    2015-07-01

    Widely distributed groups of living animals, such as the predominantly marine fish family Sciaenidae, have always attracted the attention of biogeographers to document the origins and patterns of diversification in time and space. In this study, the historical biogeography of the global Sciaenidae is reconstructed within a molecular phylogenetic framework to investigate their origin and to test the hypotheses explaining the present-day biogeographic patterns. Our data matrix comprises six mitochondrial and nuclear genes in 93 globally sampled sciaenid species from 52 genera. Within the inferred phylogenetic tree of the Sciaenidae, we identify 15 main and well-supported lineages; some of which have not been recognized previously. Reconstruction of habitat preferences shows repeated habitat transitions between marine and euryhaline environments. This implies that sciaenids can easily adapt to some variations in salinity, possibly as the consequence of their nearshore habitats and migratory life history. Conversely, complete marine/euryhaline to freshwater transitions occurred only three times, in South America, North America and South Asia. Ancestral range reconstruction analysis concomitant with fossil evidence indicates that sciaenids first originated and diversified in the tropical America during the Oligocene to Early Miocene before undergoing two range expansions, to Eastern Atlantic and to the Indo-West Pacific where a maximum species richness is observed. The uncommon biogeographic pattern identified is discussed in relation to current knowledge on origin of gradients of marine biodiversity toward the center of origin hypothesis in the Indo-West Pacific. PMID:25848970

  5. Dissolved organic C export is highly dynamic - capturing this variability and challenges in modelling

    NASA Astrophysics Data System (ADS)

    Waldron, S.; Coleman, M.; Scott, E. M.; Drew, S.

    2013-12-01

    [DOC] range of 8 - 55.6 mg/l C, with the greatest shift in a single day being 23.5 mg/l C. We will present this highly dynamic [DOC] time series and also contemporaneous data from an in-situ water chemistry sonde profiling other measures of the ';riverine circulation system': pH, conductivity, temperature and stage height. The challenge now is how to allow data series of ~17,500 measurements per annum to interact to better understand and model drivers of carbon export. We are exploring the application of wavelet analysis to identify periods of coherence between [DOC] and these other variables. Our initial results indicate show that coherence with [DOC] can be intermittent and irregular, and so the challenge sensor technology presents continues.

  6. Range and range rate system

    NASA Technical Reports Server (NTRS)

    Graham, Olin L. (Inventor); Russell, Jim K. (Inventor); Epperly, Walter L. (Inventor)

    1988-01-01

    A video controlled solid state range finding system which requires no radar, high power laser, or sophisticated laser target is disclosed. The effective range of the system is from 1 to about 200 ft. The system includes an opto-electric camera such as a lens CCD array device. A helium neon laser produces a source beam of coherent light which is applied to a beam splitter. The beam splitter applies a reference beam to the camera and produces an outgoing beam applied to a first angularly variable reflector which directs the outgoing beam to the distant object. An incoming beam is reflected from the object to a second angularly variable reflector which reflects the incoming beam to the opto-electric camera via the beam splitter. The first reflector and the second reflector are configured so that the distance travelled by the outgoing beam from the beam splitter and the first reflector is the same as the distance travelled by the incoming beam from the second reflector to the beam splitter. The reference beam produces a reference signal in the geometric center of the camera. The incoming beam produces an object signal at the camera.

  7. Development and analysis of a highly flexible multi-gene expression system for metabolic engineering in Arabidopsis seeds and other plant tissues.

    PubMed

    Shockey, Jay; Mason, Catherine; Gilbert, Matthew; Cao, Heping; Li, Xiangjun; Cahoon, Edgar; Dyer, John

    2015-09-01

    Production of novel value-added compounds in transgenic crops has become an increasingly viable approach in recent years. However, in many cases, product yield still falls short of the levels necessary for optimal profitability. Determination of the limiting factors is thus of supreme importance for the long-term viability of this approach. A significant challenge to most metabolic engineering projects is the need for strong coordinated co-expression of multiple transgenes. Strong constitutive promoters have been well-characterized during the >30 years since plant transformation techniques were developed. However, organ- or tissue-specific promoters are poorly characterized in many cases. Oilseeds are one such example. Reports spanning at least 20 years have described the use of certain seed-specific promoters to drive expression of individual transgenes. Multi-gene engineering strategies are often hampered by sub-optimal expression levels or improper tissue-specificity of particular promoters, or rely on the use of multiple copies of the same promoter, which can result in DNA instability or transgene silencing. We describe here a flexible system of plasmids that allows for expression of 1-7 genes per binary plasmid, and up to 18 genes altogether after multiple rounds of transformation or sexual crosses. This vector system includes six seed-specific promoters and two constitutive promoters. Effective constitutive and seed-specific RNA interference gene-suppression cloning vectors were also constructed for silencing of endogenous genes. Taken together, this molecular toolkit allows combinatorial cloning for multiple transgene expression in seeds, vegetative organs, or both simultaneously, while also providing the means to coordinately overexpress some genes while silencing others. PMID:26254605

  8. Driving south: a multi-gene phylogeny of the brown algal family Fucaceae reveals relationships and recent drivers of a marine radiation

    PubMed Central

    2011-01-01

    Background Understanding the processes driving speciation in marine ecosystems remained a challenge until recently, due to the unclear nature of dispersal boundaries. However, recent evidence for marine adaptive radiations and ecological speciation, as well as previously undetected patterns of cryptic speciation is overturning this view. Here, we use multi-gene phylogenetics to infer the family-level evolutionary history of Fucaceae (intertidal brown algae of the northern Pacific and Atlantic) in order to investigate recent and unique patterns of radiative speciation in the genus Fucus in the Atlantic, in contrast with the mainly monospecific extant genera. Results We developed a set of markers from 13 protein coding genes based on polymorphic cDNA from EST libraries, which provided novel resolution allowing estimation of ancestral character states and a detailed reconstruction of the recent radiative history. Phylogenetic reconstructions yielded similar topologies and revealed four independent trans-Arctic colonization events by Fucaceae lineages, two of which also involved transitions from hermaphroditism to dioecy associated with Atlantic invasions. More recently, reversion of dioecious ancestral lineages towards hermaphroditism has occurred in the genus Fucus, particularly coinciding with colonization of more extreme habitats. Novel lineages in the genus Fucus were also revealed in association with southern habitats. These most recent speciation events occurred during the Pleistocene glaciations and coincided with a shift towards selfing mating systems, generally southward shifts in distribution, and invasion of novel habitats. Conclusions Diversification of the family occurred in the Late-Mid Miocene, with at least four independent trans-Artic lineage crossings coincident with two reproductive mode transitions. The genus Fucus arose in the Pliocene but radiated within a relatively short time frame about 2.5 million years ago. Current species distributions of

  9. The importance of being genomic: Non-coding and coding sequences suggest different models of toxin multi-gene family evolution.

    PubMed

    Malhotra, Anita; Creer, Simon; Harris, John B; Thorpe, Roger S

    2015-12-01

    Studies of multi-gene protein families, including many toxins, are crucial for understanding the role of gene duplication in generating protein diversity in general. However, many evolutionary analyses of gene families are based on coding sequences, and do not take into account many potentially confounding evolutionary factors, such as recombination and convergence due to selection. We illustrate this using snake venom gene sequences from the Phospholipase A2 (PLA2) subfamily. Novel gene sequences from 20 species of understudied Asian pitvipers were analyzed alongside available genomic PLA2 sequences from another four crotaline and several viperine species. In contrast to previous analyses of this toxin family based on cDNA sequences, we find that duplication events are concentrated at the tips of the tree, suggesting that major functions such as presynaptic neurotoxicity have evolved convergently multiple times in pitvipers. We provide evidence that this discrepancy is due to differing evolutionary patterns between introns and exons. The effects of several well-known sources of bias on the phylogeny were small, compared to the effect of analyses based on different partitions of the gene (whole gene sequence, non-coding regions, cDNA sequence). Switches of function were found to be largely associated with strong selection, and with duplication events. Use of coding sequences for phylogeny estimation potentially produces incorrect inferences about the action of selection on individual lineages and sites. Our results have major implications for phylogenomic methods of functional inference as well as for our understanding of the evolution of multigene families. PMID:26359851

  10. The Directional Observation of Highly Dynamic Membrane Tubule Formation Induced by Engulfed Liposomes

    PubMed Central

    Zhang, Xiaoming; Dai, Luru; Wang, Anhe; Wölk, Christian; Dobner, Bodo; Brezesinski, Gerald; Tang, Yunqing; Wang, Xianyou; Li, Junbai

    2015-01-01

    Highly dynamic tubular structures in cells are responsible for exchanges between organelles. Compared with bacterial invasion, the most affordable and least toxic lipids were found in this study to be gentle and safe exogenous stimuli for the triggering of membrane tubules. A specific lipid system was internalized by NIH3T3 cells. Following cellular uptake, the constructed liposomes traveled towards the nucleus in aggregations and were gradually distributed into moving vesicles and tubules in the cytosol. The triggered tubules proceeded, retreated or fluctuated along the cytoskeleton and were highly dynamic, moving quickly (up to several microns per second), and breaking and fusing frequently. These elongated tubules could also fuse with one another, giving rise to polygonal membrane networks. These lipid systems, with the novel property of accelerating intracellular transport, provide a new paradigm for investigating cellular dynamics. PMID:26548331

  11. Study on UKF based federal integrated navigation for high dynamic aviation

    NASA Astrophysics Data System (ADS)

    Zhao, Gang; Shao, Wei; Chen, Kai; Yan, Jie

    2011-08-01

    High dynamic aircraft is a very attractive new generation vehicles, in which provides near space aviation with large flight envelope both speed and altitude, for example the hypersonic vehicles. The complex flight environments for high dynamic vehicles require high accuracy and stability navigation scheme. Since the conventional Strapdown Inertial Navigation System (SINS) and Global Position System (GPS) federal integrated scheme based on EKF (Extended Kalman Filter) is invalidation in GPS single blackout situation because of high speed flight, a new high precision and stability integrated navigation approach is presented in this paper, in which the SINS, GPS and Celestial Navigation System (CNS) is combined as a federal information fusion configuration based on nonlinear Unscented Kalman Filter (UKF) algorithm. Firstly, the new integrated system state error is modeled. According to this error model, the SINS system is used as the navigation solution mathematic platform. The SINS combine with GPS constitute one error estimation filter subsystem based on UKF to obtain local optimal estimation, and the SINS combine with CNS constitute another error estimation subsystem. A non-reset federated configuration filter based on partial information is proposed to fuse two local optimal estimations to get global optimal error estimation, and the global optimal estimation is used to correct the SINS navigation solution. The χ 2 fault detection method is used to detect the subsystem fault, and the fault subsystem is isolation through fault interval to protect system away from the divergence. The integrated system takes advantages of SINS, GPS and CNS to an immense improvement for high accuracy and reliably high dynamic navigation application. Simulation result shows that federated fusion of using GPS and CNS to revise SINS solution is reasonable and availably with good estimation performance, which are satisfied with the demands of high dynamic flight navigation. The UKF is

  12. GNSS Signal Tracking Performance Improvement for Highly Dynamic Receivers by Gyroscopic Mounting Crystal Oscillator.

    PubMed

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-01-01

    In this paper, the efficiency of the gyroscopic mounting method is studied for a highly dynamic GNSS receiver's reference oscillator for reducing signal loss. Analyses are performed separately in two phases, atmospheric and upper atmospheric flights. Results show that the proposed mounting reduces signal loss, especially in parts of the trajectory where its probability is the highest. This reduction effect appears especially for crystal oscillators with a low elevation angle g-sensitivity vector. The gyroscopic mounting influences frequency deviation or jitter caused by dynamic loads on replica carrier and affects the frequency locked loop (FLL) as the dominant tracking loop in highly dynamic GNSS receivers. In terms of steady-state load, the proposed mounting mostly reduces the frequency deviation below the one-sigma threshold of FLL (1σ(FLL)). The mounting method can also reduce the frequency jitter caused by sinusoidal vibrations and reduces the probability of signal loss in parts of the trajectory where the other error sources accompany this vibration load. In the case of random vibration, which is the main disturbance source of FLL, gyroscopic mounting is even able to suppress the disturbances greater than the three-sigma threshold of FLL (3σ(FLL)). In this way, signal tracking performance can be improved by the gyroscopic mounting method for highly dynamic GNSS receivers. PMID:26404286

  13. GNSS Signal Tracking Performance Improvement for Highly Dynamic Receivers by Gyroscopic Mounting Crystal Oscillator

    PubMed Central

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-01-01

    In this paper, the efficiency of the gyroscopic mounting method is studied for a highly dynamic GNSS receiver’s reference oscillator for reducing signal loss. Analyses are performed separately in two phases, atmospheric and upper atmospheric flights. Results show that the proposed mounting reduces signal loss, especially in parts of the trajectory where its probability is the highest. This reduction effect appears especially for crystal oscillators with a low elevation angle g-sensitivity vector. The gyroscopic mounting influences frequency deviation or jitter caused by dynamic loads on replica carrier and affects the frequency locked loop (FLL) as the dominant tracking loop in highly dynamic GNSS receivers. In terms of steady-state load, the proposed mounting mostly reduces the frequency deviation below the one-sigma threshold of FLL (1σFLL). The mounting method can also reduce the frequency jitter caused by sinusoidal vibrations and reduces the probability of signal loss in parts of the trajectory where the other error sources accompany this vibration load. In the case of random vibration, which is the main disturbance source of FLL, gyroscopic mounting is even able to suppress the disturbances greater than the three-sigma threshold of FLL (3σFLL). In this way, signal tracking performance can be improved by the gyroscopic mounting method for highly dynamic GNSS receivers. PMID:26404286

  14. Spatial pattern of early recruitment of Macoma balthica (L.) and Cerastoderma edule (L.) in relation to sediment dynamics on a highly dynamic intertidal sandflat

    NASA Astrophysics Data System (ADS)

    Bouma, H.; Duiker, J. M. C.; de Vries, P. P.; Herman, P. M. J.; Wolff, W. J.

    2001-05-01

    To investigate the possible relationship between sediment dynamics and spatial distribution of early bivalve recruits, a correlative field study was carried out on a highly dynamic intertidal sandflat in the Westerschelde estuary, SW Netherlands. On a spatial grid, 43 plots over an area of 700×800 m 2, early recruits (300-1000 μm mesh fraction) of the tellinid clam Macoma balthica (L.) and the edible cockle Cerastoderma edule (L.) were sampled during the spatfall period (May-June) in 1997. Data were also collected on bed-level height, sediment dynamics and -composition and abundance of adult benthos. The grid covered a range of -50 to +140 cm with respect to mean-tide level. In both species, maximum early recruitment was found at the higher part of this range of intertidal levels. The strong gradient in densities from the lower towards the higher intertidal was significantly negatively correlated with sediment dynamics. No significant correlations of early-recruit densities were found with silt content, or with densities of adult benthos. The relationship between early recruitment and bed-level height differed from that observed in Wadden Sea studies of recruits of similar size, where maximum early recruitment occurred in the lower intertidal. It is suggested that in highly dynamic environments, sediment dynamics may have an important influence on passive resuspension of early recruits and on spatial patterns of early recruitment. Based on field and model data, it is discussed which processes could cause the difference in early recruitment patterns in low and highly dynamic intertidal environments. It is concluded that the presence of low-dynamic areas is essential for the success of early recruitment, and thus for the maintenance of bivalve populations.

  15. Single molecule tracking fluorescence microscopy in mitochondria reveals highly dynamic but confined movement of Tom40

    NASA Astrophysics Data System (ADS)

    Kuzmenko, Anton; Tankov, Stoyan; English, Brian P.; Tarassov, Ivan; Tenson, Tanel; Kamenski, Piotr; Elf, Johan; Hauryliuk, Vasili

    2011-12-01

    Tom40 is an integral protein of the mitochondrial outer membrane, which as the central component of the Translocase of the Outer Membrane (TOM) complex forms a channel for protein import. We characterize the diffusion properties of individual Tom40 molecules fused to the photoconvertable fluorescent protein Dendra2 with millisecond temporal resolution. By imaging individual Tom40 molecules in intact isolated yeast mitochondria using photoactivated localization microscopy with sub-diffraction limited spatial precision, we demonstrate that Tom40 movement in the outer mitochondrial membrane is highly dynamic but confined in nature, suggesting anchoring of the TOM complex as a whole.

  16. Single molecule tracking fluorescence microscopy in mitochondria reveals highly dynamic but confined movement of Tom40

    PubMed Central

    Kuzmenko, Anton; Tankov, Stoyan; English, Brian P.; Tarassov, Ivan; Tenson, Tanel; Kamenski, Piotr; Elf, Johan; Hauryliuk, Vasili

    2011-01-01

    Tom40 is an integral protein of the mitochondrial outer membrane, which as the central component of the Translocase of the Outer Membrane (TOM) complex forms a channel for protein import. We characterize the diffusion properties of individual Tom40 molecules fused to the photoconvertable fluorescent protein Dendra2 with millisecond temporal resolution. By imaging individual Tom40 molecules in intact isolated yeast mitochondria using photoactivated localization microscopy with sub-diffraction limited spatial precision, we demonstrate that Tom40 movement in the outer mitochondrial membrane is highly dynamic but confined in nature, suggesting anchoring of the TOM complex as a whole. PMID:22355710

  17. Highly Dynamic and Adaptive Traffic Congestion Avoidance in Real-Time Inspired by Honey Bee Behavior

    NASA Astrophysics Data System (ADS)

    Wedde, Horst F.; Lehnhoff, Sebastian; van Bonn, Bernhard; Bay, Z.; Becker, S.; Böttcher, S.; Brunner, C.; Büscher, A.; Fürst, T.; Lazarescu, A. M.; Rotaru, E.; Senge, S.; Steinbach, B.; Yilmaz, F.; Zimmermann, T.

    Traffic congestions have become a major problem in metropolitan areas world-wide, within and between cities, to an extent where they make driving and transportation times largely unpredictable. Due to the highly dynamic character of congestion building and dissolving this phenomenon appears even to resist a formal treatment. Static approaches, and even more their global management, have proven counterproductive in practice. Given the latest progress in VANET technology and the remarkable commercially driven efforts like in the European C2C consortium, or the VSC Project in the US, allow meanwhile to tackle various aspects of traffic regulation through VANET communication. In this paper we introduce a novel, completely decentralized multi-agent routing algorithm (termed BeeJamA) which we have derived from the foraging behavior of honey bees. It is highly dynamic, adaptive, robust, and scalable, and it allows for both avoiding congestions, and minimizing traveling times to individual destinations. Vehicle guidance is provided well ahead of every intersection, depending on the individual speeds. Thus strict deadlines are imposed on, and respected by, the BeeJamA algorithm. We report on extensive simulation experiments which show the superior performance of BeeJamA over conventional approaches.

  18. Importance of considering intraborehole flow in solute transport modeling under highly dynamic flow conditions.

    PubMed

    Ma, Rui; Zheng, Chunmiao; Tonkin, Matt; Zachara, John M

    2011-04-01

    Correct interpretation of tracer test data is critical for understanding transport processes in the subsurface. This task can be greatly complicated by the presence of intraborehole flows in a highly dynamic flow environment. At a new tracer test site (Hanford IFRC) a dynamic flow field created by changes in the stage of the adjacent Columbia River, coupled with a heterogeneous hydraulic conductivity distribution, leads to considerable variations in vertical hydraulic gradients. These variations, in turn, create intraborehole flows in fully-screened (6.5m) observation wells with frequently alternating upward and downward movement. This phenomenon, in conjunction with a highly permeable aquifer formation and small horizontal hydraulic gradients, makes modeling analysis and model calibration a formidable challenge. Groundwater head data alone were insufficient to define the flow model boundary conditions, and the movement of the tracer was highly sensitive to the dynamics of the flow field. This study shows that model calibration can be significantly improved by explicitly considering (a) dynamic flow model boundary conditions and (b) intraborehole flow. The findings from this study underscore the difficulties in interpreting tracer tests and understanding solute transport under highly dynamic flow conditions. PMID:21216023

  19. Transient beam oscillation with a highly dynamic scanner for laser beam fusion cutting

    NASA Astrophysics Data System (ADS)

    Goppold, Cindy; Pinder, Thomas; Herwig, Patrick

    2016-02-01

    Sheet metals with thicknesses >8 mm have a distinct cutting performance. The free choice of the optical configuration composed of fiber diameter, collimation, and focal length offers many opportunities to influence the static beam geometry. Previous analysis points out the limitations of this method in the thick section area. Within the present study, an experimental investigation of fiber laser fusion cutting of 12 mm stainless steel was performed by means of dynamical beam oscillation. Two standard optical setups are combined with a highly dynamic galvano-driven scanner that achieves frequencies up to 4 kHz. Dependencies of the scanner parameter, the optical circumstances, and the conventional cutting parameters are discussed. The aim is to characterize the capabilities and challenges of the dynamic beam shaping in comparison to the state-of-the-art static beam shaping. Thus, the trials are evaluated by quality criteria of the cut edge as surface roughness and burr height, the feed rate, and the cut kerf geometry. The investigation emphasizes promising procedural possibilities for improvements of the cutting performance in the case of fiber laser fusion cutting of thick stainless steel by means of the application of a highly dynamic scanner.

  20. A recursive genetic framework for evolutionary decision-making in problems with high dynamism

    NASA Astrophysics Data System (ADS)

    Pashaei, Kaveh; Taghiyareh, Fattaneh; Badie, Kambiz

    2015-11-01

    Communication and coordination are the main cores for reaching a constructive agreement among multi-agent systems (MASs). Dividing the overall performance of MAS to individual agents may lead to group learning as opposed to individual learning, which is one of the weak points of MASs. This paper proposes a recursive genetic framework for solving problems with high dynamism. In this framework, a combination of genetic algorithm and multi-agent capabilities is utilised to accelerate team learning and accurate credit assignment. The argumentation feature is used to accomplish agent learning and the negotiation features of MASs are used to achieve a credit assignment. The proposed framework is quite general and its recursive hierarchical structure could be extended. We have dedicated one special controlling module for increasing convergence time. Due to the complexity of blackjack, we have applied it as a possible test bed to evaluate the system's performance. The learning rate of agents is measured as well as their credit assignment. The analysis of the obtained results led us to believe that our robust framework with the proposed negotiation operator is a promising methodology to solve similar problems in other areas with high dynamism.

  1. Subjective evaluation of higher dynamic range video

    NASA Astrophysics Data System (ADS)

    Hanhart, Philippe; Korshunov, Pavel; Ebrahimi, Touradj

    2014-09-01

    High dynamic range (HDR) imaging is able to capture a wide range of luminance values, closer to what the human eye can perceive. However, for capture and display technologies, it is important to answer the question on the significance of higher dynamic range for user preference. This paper answers this question by investigating the added value of higher dynamic range via a rigorous set of subjective experiments using paired comparison methodology. Video sequences at four different peak luminance levels were displayed side-by-side on a Dolby Research HDR RGB backlight dual modulation display (aka `Pulsar'), which is capable of reliably displaying video content at 4000 cd=m2 peak luminance. The results of the subjective experiment demonstrate that the preference of an average viewer increases logarithmically with the increase in the maximum luminance level at which HDR content is displayed, with 4000 cd=m2 being the most attractive option.

  2. Highly Dynamic Transcriptional Signature of Distinct Macrophage Subsets during Sterile Inflammation, Resolution, and Tissue Repair.

    PubMed

    Varga, Tamas; Mounier, Rémi; Horvath, Attila; Cuvellier, Sylvain; Dumont, Florent; Poliska, Szilard; Ardjoune, Hamida; Juban, Gaëtan; Nagy, Laszlo; Chazaud, Bénédicte

    2016-06-01

    Macrophage gene expression determines phagocyte responses and effector functions. Macrophage plasticity has been mainly addressed in in vitro models that do not account for the environmental complexity observed in vivo. In this study, we show that microarray gene expression profiling revealed a highly dynamic landscape of transcriptomic changes of Ly6C(pos)CX3CR1(lo) and Ly6C(neg)CX3CR1(hi) macrophage populations during skeletal muscle regeneration after a sterile damage. Systematic gene expression analysis revealed that the time elapsed, much more than Ly6C status, was correlated with the largest differential gene expression, indicating that the time course of inflammation was the predominant driving force of macrophage gene expression. Moreover, Ly6C(pos)/Ly6C(neg) subsets could not have been aligned to canonical M1/M2 profiles. Instead, a combination of analyses suggested the existence of four main features of muscle-derived macrophages specifying important steps of regeneration: 1) infiltrating Ly6C(pos) macrophages expressed acute-phase proteins and exhibited an inflammatory profile independent of IFN-γ, making them damage-associated macrophages; 2) metabolic changes of macrophages, characterized by a decreased glycolysis and an increased tricarboxylic acid cycle/oxidative pathway, preceded the switch to and sustained their anti-inflammatory profile; 3) Ly6C(neg) macrophages, originating from skewed Ly6C(pos) cells, actively proliferated; and 4) later on, restorative Ly6C(neg) macrophages were characterized by a novel profile, indicative of secretion of molecules involved in intercellular communications, notably matrix-related molecules. These results show the highly dynamic nature of the macrophage response at the molecular level after an acute tissue injury and subsequent repair, and associate a specific signature of macrophages to predictive specialized functions of macrophages at each step of tissue injury/repair. PMID:27183604

  3. Multi-target compressive laser ranging

    NASA Astrophysics Data System (ADS)

    Pandit, Pushkar P.; Dahl, Jason R.; Barber, Zeb W.; Babbitt, W. Randall

    2014-05-01

    Compressive laser ranging (CLR) is a method that exploits the sparsity available in the range domain using compressive sensing methods to directly obtain range domain information. Conventional ranging methods are marred by requirements of high bandwidth analog detection which includes severe SNR fall off with bandwidth in analog-to-digital conversion (ADC). Compressive laser ranging solves this problem by obtaining sub-centimeter resolution while using low bandwidth detection. High rate digital pulse pattern generators and off the shelf photonic devices are used to modulate the transmitted and received light from a superluminescent diode. CLR detection is demonstrated using low bandwidth, high dynamic range detectors along with photon counting techniques. The use of an incoherent source eliminates speckle issues and enables simplified CLR methods to get multi-target range profiles with 1-3cm resolution. Using compressive sensing methods CLR allows direct range measurements in the sub-Nyquist regime while reducing system resources, in particular the need for high bandwidth ADC.

  4. Application of a novel multi-stage signal parameter estimator to high dynamic GPS receivers

    NASA Technical Reports Server (NTRS)

    Kumar, R.

    1990-01-01

    The performance of a novel multistage estimator when applied to the estimation of the position, velocity, and acceleration of high dynamic Global Positioning System (GPS) receivers is discussed. For the present application, a two-stage specialization of the more general estimation scheme is considered, wherein the first-stage algorithm is selected to be a modified least-squares algorithm operating upon the differential signal model and referred to as differential least-squares (DLS) and the second stage is simply an extended Kalman filter (EKF). In terms of the threshold on received carrier power-to-noise power spectral density ratio (CNR), when compared to the single-stage EKF algorithm, the DLS-EKF algorithm is about 1.5-2.0 dB better in terms of threshold and outperforms the crossproduct AFC (automatic frequency control) loop by 2-5 dB. For the case when data modulation is present, the proposed scheme provides an improvement of about 6 dB in terms of CNR compared to an earlier approximate MLE (maximum likelihood estimation) scheme. There are also very significant improvements in terms of other performance measures.

  5. Active-Site Hydration and Water Diffusion in Cytochrome P450cam: A Highly Dynamic Process

    SciTech Connect

    Miao, Yinglong; Baudry, Jerome Y

    2011-01-01

    Long-timescale molecular dynamics simulations (300 ns) are performed on both the apo- (i.e., camphor-free) and camphor-bound cytochrome P450cam (CYP101). Water diffusion into and out of the protein active site is observed without biased sampling methods. During the course of the molecular dynamics simulation, an average of 6.4 water molecules is observed in the camphor-binding site of the apo form, compared to zero water molecules in the binding site of the substrate-bound form, in agreement with the number of water molecules observed in crystal structures of the same species. However, as many as 12 water molecules can be present at a given time in the camphor-binding region of the active site in the case of apo-P450cam, revealing a highly dynamic process for hydration of the protein active site, with water molecules exchanging rapidly with the bulk solvent. Water molecules are also found to exchange locations frequently inside the active site, preferentially clustering in regions surrounding the water molecules observed in the crystal structure. Potential-of-mean-force calculations identify thermodynamically favored trans-protein pathways for the diffusion of water molecules between the protein active site and the bulk solvent. Binding of camphor in the active site modifies the free-energy landscape of P450cam channels toward favoring the diffusion of water molecules out of the protein active site.

  6. Highly Dynamic Ligand Binding and Light Absorption Coefficient of Cesium Lead Bromide Perovskite Nanocrystals.

    PubMed

    De Roo, Jonathan; Ibáñez, Maria; Geiregat, Pieter; Nedelcu, Georgian; Walravens, Willem; Maes, Jorick; Martins, Jose C; Van Driessche, Isabel; Kovalenko, Maksym V; Hens, Zeger

    2016-02-23

    Lead halide perovskite materials have attracted significant attention in the context of photovoltaics and other optoelectronic applications, and recently, research efforts have been directed to nanostructured lead halide perovskites. Collodial nanocrystals (NCs) of cesium lead halides (CsPbX3, X = Cl, Br, I) exhibit bright photoluminescence, with emission tunable over the entire visible spectral region. However, previous studies on CsPbX3 NCs did not address key aspects of their chemistry and photophysics such as surface chemistry and quantitative light absorption. Here, we elaborate on the synthesis of CsPbBr3 NCs and their surface chemistry. In addition, the intrinsic absorption coefficient was determined experimentally by combining elemental analysis with accurate optical absorption measurements. (1)H solution nuclear magnetic resonance spectroscopy was used to characterize sample purity, elucidate the surface chemistry, and evaluate the influence of purification methods on the surface composition. We find that ligand binding to the NC surface is highly dynamic, and therefore, ligands are easily lost during the isolation and purification procedures. However, when a small amount of both oleic acid and oleylamine is added, the NCs can be purified, maintaining optical, colloidal, and material integrity. In addition, we find that a high amine content in the ligand shell increases the quantum yield due to the improved binding of the carboxylic acid. PMID:26786064

  7. Real-time magnetic resonance imaging of highly dynamic granular phenomena

    NASA Astrophysics Data System (ADS)

    Penn, Alexander; Pruessmann, Klaas P.; Müller, Christoph

    Probing non-intrusively the interior of three-dimensional granular systems is a challenging task for which a number of imaging techniques have been applied including positron emission particle tracking, X-ray tomography and magnetic resonance imaging (MRI). A particular advantage of MRI is its versatility allowing quantitative velocimetry through phase contrast encoding and tagging, arbitrary slice orientations and the flexibility to trade spatial for temporal resolution and vice versa during image reconstruction. However, previous attempts to image granular systems using MRI were often limited to (pseudo-) steady state systems due to the poor temporal resolution of conventional imaging methodology. Here we present an experimental approach that overcomes previous limitations in temporal resolution by implementing a variety of methodological advances, viz. parallel data acquisition through tailored multiple receiver coils, fast gradient readouts for time-efficient data sampling and engineered granular materials that contain signal sources of high proton density. Achieving a spatial and temporal resolution of, respectively, 2 mm x 2 mm and 50 ms, we were able to image highly dynamic phenomena in granular media such as bubble coalescence and granular compaction waves.

  8. Motion-blurred star acquisition method of the star tracker under high dynamic conditions.

    PubMed

    Sun, Ting; Xing, Fei; You, Zheng; Wei, Minsong

    2013-08-26

    The star tracker is one of the most promising attitude measurement devices used in spacecraft due to its extremely high accuracy. However, high dynamic performance is still one of its constraints. Smearing appears, making it more difficult to distinguish the energy dispersive star point from the noise. An effective star acquisition approach for motion-blurred star image is proposed in this work. The correlation filter and mathematical morphology algorithm is combined to enhance the signal energy and evaluate slowly varying background noise. The star point can be separated from most types of noise in this manner, making extraction and recognition easier. Partial image differentiation is then utilized to obtain the motion parameters from only one image of the star tracker based on the above process. Considering the motion model, the reference window is adopted to perform centroid determination. Star acquisition results of real on-orbit star images and laboratory validation experiments demonstrate that the method described in this work is effective and the dynamic performance of the star tracker could be improved along with more identified stars and guaranteed position accuracy of the star point. PMID:24105556

  9. Hidden persistence of salinity and productivity gradients shaping pelagic diversity in highly dynamic marine ecosystems.

    PubMed

    Hidalgo, M; Reglero, P; Álvarez-Berastegui, D; Torres, A P; Álvarez, I; Rodriguez, J M; Carbonell, A; Balbín, R; Alemany, F

    2015-03-01

    While large-scale patterns of pelagic marine diversity are generally well described, they remain elusive at regional-scale given the high temporal and spatial dynamics of biological and local oceanographic processes. We here evaluated whether the main drivers of pelagic diversity can be more pervasive than expected at regional scale, using a meroplankton community of a frontal system in the Western Mediterranean. We evidence that regional biodiversity in a highly dynamic ecosystem can be summarized attending to both static (bathymetric) and ephemeral (biological and hydrographical) environmental axes of seascape. This pattern can be observed irrespectively of the regional hydroclimatic scenario with distance to coast, salinity gradient and chlorophyll a concentration being the main and recurrent drivers. By contrast, their effect is overridden in common analyses given that different non-linear effects are buffered between years of contrasting scenarios, emerging the influence of secondary effects on diversity. We conclude that community studies may reveal hidden persistent processes when they take into account different functional effects related to hydroclimatic variability. A better understanding of regional dynamics of the pelagic realm will improve our capability to forecast future responses of plankton communities as well as impacts of climate change on marine biodiversity. PMID:25617678

  10. Analysis and compensation for code Doppler effect of BDS II signal under high dynamics

    NASA Astrophysics Data System (ADS)

    Ouyang, Xiaofeng; Zeng, Fangling

    2016-01-01

    In high dynamic circumstances, the acquisition of BDS (BeiDou Navigation Satellite System) signal would be affected by the pseudo-code Doppler. The pseudo-code frequency shift is more prominent and complex when BOC modulation has been adopted by BDS-II, but is not yet involved in current compensation algorithm. In addition, the most frequently used code Doppler compensation algorithm is modifying the sampling rate or local bit rate, which not only increases the complexity of the acquisition and tracking, but also is barely realizable for the hardware receiver to modify the local frequency. Therefore, this paper proposes a code Doppler compensation method based on double estimator receiver, which simultaneously controls NCO delay of code tracking loop and subcarrier tracking loop to compensate for pseudo-code frequency shift. The simulation and test are implemented with BDS-II BOC signal. The test results demonstrate that the proposed algorithm can effectively compensate for pseudo-code Doppler of BOC signal and has detection probability 3dB higher than the uncompensated situation when the false alarm rate is under 0.01 and the coherent integration time is 1ms.

  11. FODA: a novel efficient multiple access protocol for highly dynamic self-organizing networks

    NASA Astrophysics Data System (ADS)

    Li, Hantao; Liu, Kai; Zhang, Jun

    2005-11-01

    Based on the concept of contention reservation for polling transmission and collision prevention strategy for collision resolution, a fair on-demand access (FODA) protocol for supporting node mobility and multihop architecture in highly dynamic self-organizing networks is proposed. In the protocol, a distributed clustering network architecture formed by self-organizing algorithm and a main idea of reserving channel resources to get polling service are adopted, so that the hidden terminal (HT) and exposed terminal (ET) problems existed in traffic transmission due to multihop architecture and wireless transmission can be eliminated completely. In addition, an improved collision prevention scheme based on binary countdown algorithm (BCA), called fair collision prevention (FCP) algorithm, is proposed to greatly eliminate unfair phenomena existed in contention access of newly active ordinary nodes and completely resolve access collisions. Finally, the performance comparison of the FODA protocol with carrier sense multiple access with collision avoidance (CSMA/CA) and polling protocols by OPNET simulation are presented. Simulation results show that the FODA protocol can overcome the disadvantages of CSMA/CA and polling protocols, and achieve higher throughput, lower average message delay and less average message dropping rate.

  12. Evolutionary analysis of the highly dynamic CHEK2 duplicon in anthropoids

    PubMed Central

    2008-01-01

    Background Segmental duplications (SDs) are euchromatic portions of genomic DNA (≥ 1 kb) that occur at more than one site within the genome, and typically share a high level of sequence identity (>90%). Approximately 5% of the human genome is composed of such duplicated sequences. Here we report the detailed investigation of CHEK2 duplications. CHEK2 is a multiorgan cancer susceptibility gene encoding a cell cycle checkpoint kinase acting in the DNA-damage response signalling pathway. The continuous presence of the CHEK2 gene in all eukaryotes and its important role in maintaining genome stability prompted us to investigate the duplicative evolution and phylogeny of CHEK2 and its paralogs during anthropoid evolution. Results To study CHEK2 duplicon evolution in anthropoids we applied a combination of comparative FISH and in silico analyses. Our comparative FISH results with a CHEK2 fosmid probe revealed the single-copy status of CHEK2 in New World monkeys, Old World monkeys and gibbons. Whereas a single CHEK2 duplication was detected in orangutan, a multi-site signal pattern indicated a burst of duplication in African great apes and human. Phylogenetic analysis of paralogous and ancestral CHEK2 sequences in human, chimpanzee and rhesus macaque confirmed this burst of duplication, which occurred after the radiation of orangutan and African great apes. In addition, we used inter-species quantitative PCR to determine CHEK2 copy numbers. An amplification of CHEK2 was detected in African great apes and the highest CHEK2 copy number of all analysed species was observed in the human genome. Furthermore, we detected variation in CHEK2 copy numbers within the analysed set of human samples. Conclusion Our detailed analysis revealed the highly dynamic nature of CHEK2 duplication during anthropoid evolution. We determined a burst of CHEK2 duplication after the radiation of orangutan and African great apes and identified the highest CHEK2 copy number in human. In conclusion

  13. Multistatic short range imaging with multipath signals

    NASA Astrophysics Data System (ADS)

    Gumbmann, Frank; Ahmed, Sherif S.

    2014-10-01

    Active imaging systems in the millimeter wave region have proven to offer good results for security applications. Especially a coherent signal detection results in a high dynamic range. Several techniques and systems were published in the last years. The drawback of an active illumination of the measurement object is the effect of shading and poor illuminated areas due to specular reflections from smooth surfaces. The visibility of an object depends on its surface roughness and its relative positioning to the imaging sensor. Especially in personnel screening, the human skin behaves as a smooth mirror for millimeter waves. This paper describes the incorporation of multipath signals in the imaging process to enhance the illumination properties of active imaging systems. The proposed multipath concept is demonstrated with an active multistatic imaging system working from 70 to 80 GHz for security applications.

  14. Telemetry Ranging: Concepts

    NASA Astrophysics Data System (ADS)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2015-11-01

    Telemetry ranging is a proposed alternative to conventional two-way ranging for determining the two-way time delay between a Deep Space Station (DSS) and a spacecraft. The advantage of telemetry ranging is that the ranging signal on the uplink is not echoed to the downlink, so that telemetry alone modulates the downlink carrier. The timing information needed on the downlink, in order to determine the two-way time delay, is obtained from telemetry frames. This article describes the phase and timing estimates required for telemetry ranging, and how two-way range is calculated from these estimates. It explains why the telemetry ranging architecture does not require the spacecraft transponder to have a high-frequency or high-quality oscillator, and it describes how a telemetry ranging system can be infused in the Deep Space Network.

  15. Limited range of motion

    MedlinePlus

    Limited range of motion is a term meaning that a joint or body part cannot move through its normal range of motion. ... Motion may be limited because of a problem within the joint, swelling of tissue around the joint, ...

  16. SAR ambiguous range suppression.

    SciTech Connect

    Doerry, Armin Walter

    2006-09-01

    Pulsed Radar systems suffer range ambiguities, that is, echoes from pulses transmitted at different times arrive at the receiver simultaneously. Conventional mitigation techniques are not always adequate. However, pulse modulation schemes exist that allow separation of ambiguous ranges in Doppler space, allowing easy filtering of problematic ambiguous ranges.

  17. RADIO RANGING DEVICE

    DOEpatents

    Nieset, R.T.

    1961-05-16

    A radio ranging device is described. It utilizes a super regenerative detector-oscillator in which echoes of transmitted pulses are received in proper phase to reduce noise energy at a selected range and also at multiples of the selected range.

  18. Long Range Technology Planning.

    ERIC Educational Resources Information Center

    Ambron, Sueann, Ed.

    1986-01-01

    This summary of a meeting of the Apple Education Advisory Council, on long range technology plans at the state, county, district, and school levels, includes highlights from group discussions on future planning, staff development, and curriculum. Three long range technology plans at the state level are provided: Long Range Educational Technology…

  19. Telemetry Ranging: Signal Processing

    NASA Astrophysics Data System (ADS)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2016-02-01

    This article describes the details of the signal processing used in a telemetry ranging system in which timing information is extracted from the downlink telemetry signal in order to compute spacecraft range. A previous article describes telemetry ranging concepts and architecture, which are a slight variation of a scheme published earlier. As in that earlier work, the telemetry ranging concept eliminates the need for a dedicated downlink ranging signal to communicate the necessary timing information. The present article describes the operation and performance of the major receiver functions on the spacecraft and the ground --- many of which are standard tracking loops already in use in JPL's flight and ground radios --- and how they can be used to provide the relevant information for making a range measurement. It also describes the implementation of these functions in software, and performance of an end-to-end software simulation of the telemetry ranging system.

  20. Telemetry-Based Ranging

    NASA Technical Reports Server (NTRS)

    Hamkins, Jon; Vilnrotter, Victor A.; Andrews, Kenneth S.; Shambayati, Shervin

    2011-01-01

    A telemetry-based ranging scheme was developed in which the downlink ranging signal is eliminated, and the range is computed directly from the downlink telemetry signal. This is the first Deep Space Network (DSN) ranging technology that does not require the spacecraft to transmit a separate ranging signal. By contrast, the evolutionary ranging techniques used over the years by NASA missions, including sequential ranging (transmission of a sequence of sinusoids) and PN-ranging (transmission of a pseudo-noise sequence) whether regenerative (spacecraft acquires, then regenerates and retransmits a noise-free ranging signal) or transparent (spacecraft feeds the noisy demodulated uplink ranging signal into the downlink phase modulator) relied on spacecraft power and bandwidth to transmit an explicit ranging signal. The state of the art in ranging is described in an emerging CCSDS (Consultative Committee for Space Data Systems) standard, in which a pseudo-noise (PN) sequence is transmitted from the ground to the spacecraft, acquired onboard, and the PN sequence is coherently retransmitted back to the ground, where a delay measurement is made between the uplink and downlink signals. In this work, the telemetry signal is aligned with the uplink PN code epoch. The ground station computes the delay between the uplink signal transmission and the received downlink telemetry. Such a computation is feasible because symbol synchronizability is already an integral part of the telemetry design. Under existing technology, the telemetry signal cannot be used for ranging because its arrival-time information is not coherent with any Earth reference signal. By introducing this coherence, and performing joint telemetry detection and arrival-time estimation on the ground, a high-rate telemetry signal can provide all the precision necessary for spacecraft ranging.

  1. Improved ranging systems

    NASA Technical Reports Server (NTRS)

    Young, Larry E.

    1989-01-01

    Spacecraft range measurements have provided the most accurate tests, to date, of some relativistic gravitational parameters, even though the measurements were made with ranging systems having error budgets of about 10 meters. Technology is now available to allow an improvement of two orders of magnitude in the accuracy of spacecraft ranging. The largest gains in accuracy result from the replacement of unstable analog components with high speed digital circuits having precisely known delays and phase shifts.

  2. Automatic range selector

    DOEpatents

    McNeilly, Clyde E.

    1977-01-04

    A device is provided for automatically selecting from a plurality of ranges of a scale of values to which a meter may be made responsive, that range which encompasses the value of an unknown parameter. A meter relay indicates whether the unknown is of greater or lesser value than the range to which the meter is then responsive. The rotatable part of a stepping relay is rotated in one direction or the other in response to the indication from the meter relay. Various positions of the rotatable part are associated with particular scales. Switching means are sensitive to the position of the rotatable part to couple the associated range to the meter.

  3. Range Scheduling Aid (RSA)

    NASA Technical Reports Server (NTRS)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  4. Laser ranging data analysis

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Near real-time Lageos laser ranging data are analyzed in terms of range bias, time bias, and internal precision, and estimates for earth orientation parameters X(sub p), Y(sub p), and UT1 are obtained. The results of these analyses are reported in a variety of formats. Copies of monthly summaries from November, 1986 through November, 1987 are included.

  5. Home range and travels

    USGS Publications Warehouse

    Stickel, L.F.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  6. Topology Control in Large-Scale High Dynamic Mobile Ad-Hoc Networks

    NASA Astrophysics Data System (ADS)

    El-Habbal, Mohamed; Rückert, Ulrich; Witkowski, Ulf

    We present our contribution in projects related to ad-hoc networking using different routing protocols and hardware platforms, showing our results and new solutions regarding topology control and routing protocols. We mainly focus on our work in the GUARDIANS EU-project, where as a main disaster scenario a large industrial warehouse on fire is assumed. The paper presents the simulation results for the routing protocols ACR, DSR and EDSR, as well as the implementation of down-scaled demos for supporting the autonomous team of robots as well as the human squad team with robust communication coverage. Various hardware platforms were used in the demos for distance measurement, based on laser range finder and radio communication with time of flight analysis.

  7. Preliminary error budget for an optical ranging system: Range, range rate, and differenced range observables

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Finger, M. H.

    1990-01-01

    Future missions to the outer solar system or human exploration of Mars may use telemetry systems based on optical rather than radio transmitters. Pulsed laser transmission can be used to deliver telemetry rates of about 100 kbits/sec with an efficiency of several bits for each detected photon. Navigational observables that can be derived from timing pulsed laser signals are discussed. Error budgets are presented based on nominal ground stations and spacecraft-transceiver designs. Assuming a pulsed optical uplink signal, two-way range accuracy may approach the few centimeter level imposed by the troposphere uncertainty. Angular information can be achieved from differenced one-way range using two ground stations with the accuracy limited by the length of the available baseline and by clock synchronization and troposphere errors. A method of synchronizing the ground station clocks using optical ranging measurements is presented. This could allow differenced range accuracy to reach the few centimeter troposphere limit.

  8. Snowy Range Wilderness, Wyoming

    SciTech Connect

    Houston, R.S.; Bigsby, P.R.

    1984-01-01

    A mineral survey of the Snowy Range Wilderness was undertaken by the USGS and USBM in 1976-1978 and was followed up with more detailed geologic and geochemical surveys, culminating in diamond drilling of one hole in the Snowy Range Wilderness. No mineral deposits were identified in the Snowy Range Wilderness, but inasmuch as low-grade uranium and associated gold resources were identified in rocks similar to those of the northern Snowy Range Wilderness in an area about 5 mi northeast of the wilderness boundary, we conclude that the northern half of the wilderness has a probable-resource potential for uranium and gold. Closely spaced drilling would be required to completely evaluate this mineral potential. The geologic terrane precludes the occurrence of fossil fuels.

  9. Full range resistive thermometers

    NASA Astrophysics Data System (ADS)

    Olivieri, E.; Rotter, M.; De Combarieu, M.; Forget, P.; Marrache-Kikuchi, C.; Pari, P.

    2015-12-01

    Resistive thermometers are widely used in low temperature physics, thanks to portability, simplicity of operation and reduced size. The possibility to precisely follow the temperature from room temperature down to the mK region is of major interest for numerous applications, although no single thermometer can nowadays cover this entire temperature range. In this article we report on a method to realize a full range thermometer, capable to measure, by itself, temperatures in the whole above-cited temperature range, with constant sensitivity and sufficient precision for the typical cryogenic applications. We present here the first results for three different full range thermometer prototypes. A detailed description of the set-up used for measurements and characterization is also reported.

  10. A New Inertial Aid Method for High Dynamic Compass Signal Tracking Based on a Nonlinear Tracking Differentiator

    PubMed Central

    Guo, Yao; Wu, Wenqi; Tang, Kanghua

    2012-01-01

    In Compass/INS integrated navigation systems, feedback inertial navigation solutions to baseband tracking loops may eliminate receiver dynamic effects, and effectively improve the tracking accuracy and sensitivity. In the conventional inertially-aided tracking loop, the satellite-receiver line-of-sight velocity is used directly to adjust local carrier frequency. However, if the inertial solution drifts, the phase tracking error will be enlarged. By using Kalman filter based carrier phase tracking loop, this paper introduces a new inertial aid method, in which the line-of-sight jerk obtained from inertial acceleration by a nonlinear tracking differentiator is used to adjust relevant parameters of the Kalman filter's process noise matrix. Validation is achieved through high dynamic Compass B3 signal with line-of-sight jerk of 10 g/s collected by a GNSS simulator. Experimental results indicate that the new inertial aid method proposed in this paper is free of the impact of the receiver dynamic and inertial errors. Therefore, when the integrated navigation system is starting or re-tracking after losing lock, the inertial error is absent from the navigation solution correction that induces large drift, and the new aid method proposed in this paper can track highly dynamic signals. PMID:22969365

  11. Mu-2 ranging

    NASA Technical Reports Server (NTRS)

    Martin, W. L.; Zygielbaum, A. I.

    1977-01-01

    The Mu-II Dual-Channel Sequential Ranging System designed as a model for future Deep Space Network ranging equipment is described. A list of design objectives is followed by a theoretical explanation of the digital demodulation techniques first employed in this machine. Hardware and software implementation are discussed, together with the details relating to the construction of the device. Two appendixes are included relating to the programming and operation of this equipment to yield the maximum scientific data.

  12. Results From F-18B Stability and Control Parameter Estimation Flight Tests at High Dynamic Pressures

    NASA Technical Reports Server (NTRS)

    Moes, Timothy R.; Noffz, Gregory K.; Iliff, Kenneth W.

    2000-01-01

    A maximum-likelihood output-error parameter estimation technique has been used to obtain stability and control derivatives for the NASA F-18B Systems Research Aircraft. This work has been performed to support flight testing of the active aeroelastic wing (AAW) F-18A project. The goal of this research is to obtain baseline F-18 stability and control derivatives that will form the foundation of the aerodynamic model for the AAW aircraft configuration. Flight data have been obtained at Mach numbers between 0.85 and 1.30 and at dynamic pressures ranging between 600 and 1500 lbf/sq ft. At each test condition, longitudinal and lateral-directional doublets have been performed using an automated onboard excitation system. The doublet maneuver consists of a series of single-surface inputs so that individual control-surface motions cannot be correlated with other control-surface motions. Flight test results have shown that several stability and control derivatives are significantly different than prescribed by the F-18B aerodynamic model. This report defines the parameter estimation technique used, presents stability and control derivative results, compares the results with predictions based on the current F-18B aerodynamic model, and shows improvements to the nonlinear simulation using updated derivatives from this research.

  13. Laser Ranging Simulation Program

    NASA Technical Reports Server (NTRS)

    Piazolla, Sabino; Hemmati, Hamid; Tratt, David

    2003-01-01

    Laser Ranging Simulation Program (LRSP) is a computer program that predicts selected aspects of the performances of a laser altimeter or other laser ranging or remote-sensing systems and is especially applicable to a laser-based system used to map terrain from a distance of several kilometers. Designed to run in a more recent version (5 or higher) of the MATLAB programming language, LRSP exploits the numerical and graphical capabilities of MATLAB. LRSP generates a graphical user interface that includes a pop-up menu that prompts the user for the input of data that determine the performance of a laser ranging system. Examples of input data include duration and energy of the laser pulse, the laser wavelength, the width of the laser beam, and several parameters that characterize the transmitting and receiving optics, the receiving electronic circuitry, and the optical properties of the atmosphere and the terrain. When the input data have been entered, LRSP computes the signal-to-noise ratio as a function of range, signal and noise currents, and ranging and pointing errors.

  14. The range scheduling aid

    NASA Technical Reports Server (NTRS)

    Halbfinger, Eliezer M.; Smith, Barry D.

    1991-01-01

    The Air Force Space Command schedules telemetry, tracking and control activities across the Air Force Satellite Control network. The Range Scheduling Aid (RSA) is a rapid prototype combining a user-friendly, portable, graphical interface with a sophisticated object-oriented database. The RSA has been a rapid prototyping effort whose purpose is to elucidate and define suitable technology for enhancing the performance of the range schedulers. Designing a system to assist schedulers in their task and using their current techniques as well as enhancements enabled by an electronic environment, has created a continuously developing model that will serve as a standard for future range scheduling systems. The RSA system is easy to use, easily ported between platforms, fast, and provides a set of tools for the scheduler that substantially increases his productivity.

  15. Satellite Laser Ranging operations

    NASA Technical Reports Server (NTRS)

    Pearlman, Michael R.

    1994-01-01

    Satellite Laser Ranging (SLR) is currently providing precision orbit determination for measurements of: 1) Ocean surface topography from satellite borne radar altimetry, 2) Spatial and temporal variations of the gravity field, 3) Earth and ocean tides, 4) Plate tectonic and regional deformation, 5) Post-glacial uplift and subsidence, 6) Variations in the Earth's center-of-mass, and 7) Variations in Earth rotation. SLR also supports specialized programs in time transfer and classical geodetic positioning, and will soon provide precision ranging to support experiments in relativity.

  16. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    This viewgraph presentation reviews the work of the Western Aeronautical Test Range (WATR). NASA's Western Aeronautical Test Range is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). Maps show the general location of the WATR area that is used for aeronautical testing and evaluation. The products, services and facilities of WATR are discussed,

  17. Mobile satellite ranging

    NASA Technical Reports Server (NTRS)

    Silverberg, E. C.

    1978-01-01

    A brief review of the constraints which have limited satellite ranging hardware and an outline of the steps which are underway to improve the status of the equipment in this area are given. In addition, some suggestions are presented for the utilization of newer instruments and for possible future research and development work in this area.

  18. STDN ranging equipment

    NASA Technical Reports Server (NTRS)

    Jones, C. E.

    1975-01-01

    Final results of the Spaceflight Tracking and Data Network (STDN) Ranging Equipment program are summarized. Basic design concepts and final design approaches are described. Theoretical analyses which define requirements and support the design approaches are presented. Design verification criteria are delineated and verification test results are specified.

  19. Agriculture, forest, and range

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The findings and recommendations of the panel for developing a satellite remote-sensing global information system in the next decade are reported. User requirements were identified in five categories: (1) cultivated crops, (2) land resources, (3)water resources, (4)forest management, and (5) range management. The benefits from the applications of satellite data are discussed.

  20. Agriculture, forestry, range resources

    NASA Technical Reports Server (NTRS)

    Crea, W. J.

    1974-01-01

    In the area of crop specie identification, it has been found that temporal data analysis, preliminary stratification, and unequal probability analysis were several of the factors that contributed to high identification accuracies. Single data set accuracies on fields of greater than 80,000 sq m (20 acres) are in the 70- to 90-percent range; however, with the use of temporal data, accuracies of 95 percent have been reported. Identification accuracy drops off significantly on areas of less than 80,000 sq m (20 acres) as does measurement accuracy. Forest stratification into coniferous and deciduous areas has been accomplished to a 90- to 95-percent accuracy level. Using multistage sampling techniques, the timber volume of a national forest district has been estimated to a confidence level and standard deviation acceptable to the Forest Service at a very favorable cost-benefit time ratio. Range specie/plant community vegetation mapping has been accomplished at various levels of success (69- to 90-percent accuracy). However, several investigators have obtained encouraging initial results in range biomass (forage production) estimation and range readiness predictions. Soil association map correction and soil association mapping in new area appear to have been proven feasible on large areas; however, testing in a complex soil area should be undertaken.

  1. Agriculture, forestry, range resources

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.

    1974-01-01

    The necessary elements to perform global inventories of agriculture, forestry, and range resources are being brought together through the use of satellites, sensors, computers, mathematics, and phenomenology. Results of ERTS-1 applications in these areas, as well as soil mapping, are described.

  2. Fact Sheet: Range Complex

    NASA Technical Reports Server (NTRS)

    Cornelson, C.; Fretter, E.

    2004-01-01

    NASA Ames has a long tradition in leadership with the use of ballistic ranges and shock tubes for the purpose of studying the physics and phenomena associated with hypervelocity flight. Cutting-edge areas of research run the gamut from aerodynamics, to impact physics, to flow-field structure and chemistry. This legacy of testing began in the NACA era of the 1940's with the Supersonic Free Flight Tunnel, and evolved dramatically up through the late 1950s with the pioneering work in the Ames Hypersonic Ballistic Range. The tradition continued in the mid-60s with the commissioning of the three newest facilities: the Ames Vertical Gun Range (AVGR) in 1964, the Hypervelocity Free Flight Facility (HFFF) in 1965 and the Electric Arc Shock Tube (EAST) in 1966. Today the Range Complex continues to provide unique and critical testing in support of the Nation's programs for planetary geology and geophysics; exobiology; solar system origins; earth atmospheric entry, planetary entry, and aerobraking vehicles; and various configurations for supersonic and hypersonic aircraft.

  3. RADIO RANGING DEVICE

    DOEpatents

    Bogle, R.W.

    1960-11-22

    A description is given of a super-regenerative oscillator ranging device provided with radiating and receiving means and being capable of indicating the occurrence of that distance between itself and a reflecting object which so phases the received echo of energy of a preceding emitted oscillation that the intervals between oscillations become uniform.

  4. Front Range Branch Officers

    NASA Astrophysics Data System (ADS)

    The Front Range Branch of AGU has installed officers for 1990: Ray Noble, National Center for Atmospheric Research, chair; Sherry Oaks, U.S. Geological Survey, chair-elect; Howard Garcia, NOAA, treasurer; Catharine Skokan, Colorado School of Mines, secretary. JoAnn Joselyn of NOAA is past chair. Members at large are Wallace Campbell, NOAA; William Neff, USGS; and Stephen Schneider, NCAR.

  5. Space-Based Range

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Space-Based Range (SBR), previously known as Space-Based Telemetry and Range Safety (STARS), is a multicenter NASA proof-of-concept project to determine if space-based communications using NASA's Tracking and Data Relay Satellite System (TDRSS) can support the Range Safety functions of acquiring tracking data and generating flight termination signals, while also providing broadband Range User data such as voice, video, and vehicle/payload data. There was a successful test of the Range Safety system at Wallops Flight Facility (WFF) on December 20, 2005, on a two-stage Terrier-Orion spin-stabilized sounding rocket. SBR transmitted GPS tracking data and maintained links with two TDRSS satellites simultaneously during the 10-min flight. The payload section deployed a parachute, landed in the Atlantic Ocean about 90 miles downrange from the launch site, and was successfully recovered. During the Terrier-Orion tests flights, more than 99 percent of all forward commands and more than 95 percent of all return frames were successfully received and processed. The time latency necessary for a command to travel from WFF over landlines to White Sands Complex and then to the vehicle via TDRSS, be processed onboard, and then be sent back to WFF was between 1.0 s and 1.1 s. The forward-link margins for TDRS-10 (TDRS East [TDE]) were 11 dB to 12 dB plus or minus 2 dB, and for TDRS-4 (TDRS Spare [TDS]) were 9 dB to 10 dB plus or minus 1.5 dB. The return-link margins for both TDE and TDS were 6 dB to 8 dB plus or minus 3 dB. There were 11 flights on an F-15B at Dryden Flight Research Center (DFRC) between November 2006 and February 2007. The Range User system tested a 184-element TDRSS Ku-band (15 GHz) phased-array antenna with data rates of 5 Mbps and 10 Mbps. This data was a combination of black-and-white cockpit video, Range Safety tracking and transceiver data, and aircraft and antenna controller data streams. IP data formatting was used.

  6. Light beam range finder

    DOEpatents

    McEwan, Thomas E.

    1998-01-01

    A "laser tape measure" for measuring distance which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%.

  7. Light beam range finder

    DOEpatents

    McEwan, T.E.

    1998-06-16

    A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.

  8. Front Range Report, Abstracts

    NASA Astrophysics Data System (ADS)

    Spence, William

    The second regional conference of the Front Range Branch, AGU, was attended by more than 80 professionals and some 20 outstanding high school students. The conference included 2 days of interdisciplinary talks, and lots of discussion, that primarily were keyed to geophysical studies of Colorado, Wyoming, and New Mexico. Other talks reported on nonregional, and sometimes global, studies being done by geophypsicists of the Front Range region.Topics included tectonics of the Front Range and the Colorado Plateau, pollution of the Arkansas and Mississippi rivers, and a supreme polluting event that caused the late-Cretaceous extinctions. Other notable talks were on toxic cleanup, microburst (wind shear) detection at U.S. airports, and other meteorological studies. Several talks treated the audience to the excitement of new work and surprise discoveries. The meeting was multimedia, including the playing of two videos through a projection TV and the playing of a fascinating tape between an airport control tower and incoming pilots during a severe microburst event.

  9. Organic sonobuoy ranging

    NASA Astrophysics Data System (ADS)

    Felgate, Nick

    2002-11-01

    It is important that military vessels periodically check their passive signatures for vunerabilities. Traditionally, this is undertaken on a fixed range (e.g., AUTEC, BUTEC) with low noise conditions. However, for operational and cost reasons it is desirable to be able to undertake such measurements while the asset is operating in other areas using expendable buoys deployed by the vessel itself. As well as the wet-end hardware for such organic sonobuoy ranging systems (e.g., calibrated sonobuoys, calibrated data uplink channels), careful consideration is needed of the signal-processing required in the harsher environmental conditions of the open ocean. In particular, it is noted that the open ocean is usually much noisier, and the propagation conditions more variable. To overcome signal-to-noise problems, techniques such as Doppler-correction, zero-padding/peak-picking, and noise estimation/correction techniques have been developed to provide accurate and unbiased estimates of received levels. To estimate propagation loss for source level estimation, a model of multipath effects has been included with the ability for analysts to compare predicted and observed received levels against time/range and adjust modeling parameters (e.g., surface loss, bottom loss, source depth) to improve the fit.

  10. Wide-range dynamic magnetic resonance elastography.

    PubMed

    Riek, Kerstin; Klatt, Dieter; Nuzha, Hassan; Mueller, Susanne; Neumann, Ulf; Sack, Ingolf; Braun, Jürgen

    2011-04-29

    Tissue mechanical parameters have been shown to be highly sensitive to disease by elastography. Magnetic resonance elastography (MRE) in the human body relies on the low-dynamic range of tissue mechanics <100 Hz. In contrast, MRE suited for investigations of mice or small tissue samples requires vibration frequencies 10-20 times higher than those used in human MRE. The dispersion of the complex shear modulus (G(⁎)) prevents direct comparison of elastography data at different frequency bands and, consequently, frequency-independent viscoelastic models that fit to G(*) over a wide dynamic range have to be employed. This study presents data of G(*) of samples of agarose gel, liver, brain, and muscle measured by high-resolution MRE in a 7T-animal scanner at 200-800 Hz vibration frequency. Material constants μ and α according to the springpot model and related to shear elasticity and slope of the G(*)-dispersion were determined. Both μ and α of calf brain and bovine liver were found to be similar, while a sample of fibrotic human liver (METAVIR score of 3) displayed about fifteen times higher shear elasticity, similar to μ of bovine muscle measured in muscle fiber direction. α was the highest in fibrotic liver, followed by normal brain and liver, while muscle had the lowest α-values of all biological samples investigated in this study. As expected, the least G(*)-dispersion was seen in soft gel. The proposed technique of wide-range dynamic MRE can provide baseline data for both human MRE and high-dynamic MRE for better understanding tissue mechanics of different tissue structures. PMID:21295305

  11. Neutron range spectrometer

    DOEpatents

    Manglos, S.H.

    1988-03-10

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

  12. Gas cooking range

    SciTech Connect

    Narang, R.K.; Narang, K.

    1984-02-14

    An energy-efficient gas cooking range features an oven section with improved heat circulation and air preheat, a compact oven/broiler burner, a smoke-free drip pan, an efficient piloted ignition, flame-containing rangetop burner rings, and a small, portable oven that can be supported on the burner rings. Panels spaced away from the oven walls and circulation fans provide very effective air flow within the oven. A gas shutoff valve automatically controls the discharge of heated gases from the oven so that they are discharged only when combustion is occurring.

  13. Monocular visual ranging

    NASA Astrophysics Data System (ADS)

    Witus, Gary; Hunt, Shawn

    2008-04-01

    The vision system of a mobile robot for checkpoint and perimeter security inspection performs multiple functions: providing surveillance video, providing high resolution still images, and providing video for semi-autonomous visual navigation. Mid-priced commercial digital cameras support the primary inspection functions. Semi-autonomous visual navigation is a tertiary function whose purpose is to reduce the burden of teleoperation and free the security personnel for their primary functions. Approaches to robot visual navigation require some form of depth perception for speed control to prevent the robot from colliding with objects. In this paper present the initial results of an exploration of the capabilities and limitations of using a single monocular commercial digital camera for depth perception. Our approach combines complementary methods in alternating stationary and moving behaviors. When the platform is stationary, it computes a range image from differential blur in the image stack collected at multiple focus settings. When the robot is moving, it extracts an estimate of range from the camera auto-focus function, and combines this with an estimate derived from angular expansion of a constellation of visual tracking points.

  14. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    NASA's Western Aeronautical Test Range (WATR) is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). It is managed by the Aeronautics Test Program (ATP) of the Aeronautics Research Mission Directorate (ARMD) to provide the right facility at the right time. NASA is a tenant on Edwards Air Force Base and has an agreement with the Air Force Flight Test Center to use the land and airspace controlled by the Department of Defense (DoD). The topics include: 1) The WATR supports a variety of vehicles; 2) Dryden shares airspace with the AFFTC; 3) Restricted airspace, corridors, and special use areas are available for experimental aircraft; 4) WATR Products and Services; 5) WATR Support Configuration; 6) Telemetry Tracking; 7) Time Space Positioning; 8) Video; 9) Voice Communication; 10) Mobile Operations Facilities; 11) Data Processing; 12) Mission Control Center; 13) Real-Time Data Analysis; and 14) Range Safety.

  15. Range Process Simulation Tool

    NASA Technical Reports Server (NTRS)

    Phillips, Dave; Haas, William; Barth, Tim; Benjamin, Perakath; Graul, Michael; Bagatourova, Olga

    2005-01-01

    Range Process Simulation Tool (RPST) is a computer program that assists managers in rapidly predicting and quantitatively assessing the operational effects of proposed technological additions to, and/or upgrades of, complex facilities and engineering systems such as the Eastern Test Range. Originally designed for application to space transportation systems, RPST is also suitable for assessing effects of proposed changes in industrial facilities and large organizations. RPST follows a model-based approach that includes finite-capacity schedule analysis and discrete-event process simulation. A component-based, scalable, open architecture makes RPST easily and rapidly tailorable for diverse applications. Specific RPST functions include: (1) definition of analysis objectives and performance metrics; (2) selection of process templates from a processtemplate library; (3) configuration of process models for detailed simulation and schedule analysis; (4) design of operations- analysis experiments; (5) schedule and simulation-based process analysis; and (6) optimization of performance by use of genetic algorithms and simulated annealing. The main benefits afforded by RPST are provision of information that can be used to reduce costs of operation and maintenance, and the capability for affordable, accurate, and reliable prediction and exploration of the consequences of many alternative proposed decisions.

  16. MiniAERCam Ranging

    NASA Technical Reports Server (NTRS)

    Talley, Tom

    2003-01-01

    Johnson Space Center (JSC) is designing a small, remotely controlled vehicle that will carry two color and one black and white video cameras in space. The device will launch and retrieve from the Space Vehicle and be used for remote viewing. Off the shelf cellular technology is being used as the basis for communication system design. Existing plans include using multiple antennas to make simultaneous estimates of the azimuth of the MiniAERCam from several sites on the Space Station and use triangulation to find the location of the device. Adding range detection capability to each of the nodes on the Space Vehicle would allow an estimate of the location of the MiniAERCam to be made at each Communication And Telemetry Box (CATBox) independent of all the other communication nodes. This project will investigate the techniques used by the Global Positioning System (GPS) to achieve accurate positioning information and adapt those strategies that are appropriate to the design of the CATBox range determination system.

  17. Range imaging laser radar

    DOEpatents

    Scott, Marion W.

    1990-01-01

    A laser source is operated continuously and modulated periodically (typicy sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream.

  18. Range imaging laser radar

    DOEpatents

    Scott, M.W.

    1990-06-19

    A laser source is operated continuously and modulated periodically (typically sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream. 2 figs.

  19. Neutron range spectrometer

    DOEpatents

    Manglos, Stephen H.

    1989-06-06

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

  20. A Pd4Br4 macrocycle trapped by cocrystallization from a highly dynamic equilibrium of η(3)-cycloheptatrienide complexes.

    PubMed

    Jandl, C; Stegbauer, S; Pöthig, A

    2016-07-01

    In the coordination chemistry of palladium, dimers bridged via halides are a common motif. Higher oligomers, however, are still rare. We report the structure of an alternating eight-membered [Pd4Br4](4-) ring framed by cycloheptatrienide ligands, which was obtained by cocrystallization of dimers and tetramers of the complex salt bromido{η(3)-[3-(2,6-diisopropylphenyl)imidazolium-1-yl]cycloheptatrienido}palladium(II) tetrafluoroborate, namely bis[di-μ-bromido-bis({η(3)-[3-(2,6-diisopropylphenyl)imidazolium-1-yl]cycloheptatrienido}palladium(II))] cyclo-tetra-μ-bromido-tetrakis({η(3)-[3-(2,6-diisopropylphenyl)imidazolium-1-yl]cycloheptatrienido}palladium(II)) octakis(tetrafluoroborate) dichloromethane octasolvate, [Pd4Br4(C22H26N2)4][Pd2Br2(C22H26N2)2]2(BF4)8·8CH2Cl2. These dimers and tetramers form a highly dynamic equilibrium in solution which was studied by low-temperature NMR spectroscopy. In the light of the presented results, tetrameric Pd(II) species can be assumed to co-exist as a second species in many cases where by current knowledge only a dimeric compound would be expected. PMID:27377269

  1. Highly Dynamic Interactions Maintain Kinetic Stability of the ClpXP Protease During the ATP-Fueled Mechanical Cycle.

    PubMed

    Amor, Alvaro J; Schmitz, Karl R; Sello, Jason K; Baker, Tania A; Sauer, Robert T

    2016-06-17

    The ClpXP protease assembles in a reaction in which an ATP-bound ring hexamer of ClpX binds to one or both heptameric rings of the ClpP peptidase. Contacts between ClpX IGF-loops and clefts on a ClpP ring stabilize the complex. How ClpXP stability is maintained during the ATP-hydrolysis cycle that powers mechanical unfolding and translocation of protein substrates is poorly understood. Here, we use a real-time kinetic assay to monitor the effects of nucleotides on the assembly and disassembly of ClpXP. When ATP is present, complexes containing single-chain ClpX assemble via an intermediate and remain intact until transferred into buffers containing ADP or no nucleotides. ATP binding to high-affinity subunits of the ClpX hexamer prevents rapid dissociation, but additional subunits must be occupied to promote assembly. Small-molecule acyldepsipeptides, which compete with the IGF loops of ClpX for ClpP-cleft binding, cause exceptionally rapid dissociation of otherwise stable ClpXP complexes, suggesting that the IGF-loop interactions with ClpP must be highly dynamic. Our results indicate that the ClpX hexamer spends almost no time in an ATP-free state during the ATPase cycle, allowing highly processive degradation of protein substrates. PMID:27003103

  2. Novel Gyroscopic Mounting for Crystal Oscillators to Increase Short and Medium Term Stability under Highly Dynamic Conditions

    PubMed Central

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-01-01

    In this paper, a gyroscopic mounting method for crystal oscillators to reduce the impact of dynamic loads on their output stability has been proposed. In order to prove the efficiency of this mounting approach, each dynamic load-induced instability has been analyzed in detail. A statistical study has been performed on the elevation angle of the g-sensitivity vector of Stress Compensated-cut (SC-cut) crystals. The analysis results show that the proposed gyroscopic mounting method gives good performance for host vehicle attitude changes. A phase noise improvement of 27 dB maximum and 5.7 dB on average can be achieved in the case of steady state loads, while under sinusoidal vibration conditions, the maximum and average phase noise improvement are as high as 24 dB and 7.5 dB respectively. With this gyroscopic mounting method, random vibration-induced phase noise instability is reduced 30 dB maximum and 8.7 dB on average. Good effects are apparent for crystal g-sensitivity vectors with low elevation angle φ and azimuthal angle β. under highly dynamic conditions, indicating the probability that crystal oscillator instability will be significantly reduced by using the proposed mounting approach. PMID:26091393

  3. Enhancement of concentration range of chromatographically detectable components with array detector mass spectrometry

    DOEpatents

    Enke, Christie

    2013-02-19

    Methods and instruments for high dynamic range analysis of sample components are described. A sample is subjected to time-dependent separation, ionized, and the ions dispersed with a constant integration time across an array of detectors according to the ions m/z values. Each of the detectors in the array has a dynamically adjustable gain or a logarithmic response function, producing an instrument capable of detecting a ratio of responses or 4 or more orders of magnitude.

  4. On image sensor dynamic range utilized by security cameras

    NASA Astrophysics Data System (ADS)

    Johannesson, Anders

    2012-03-01

    The dynamic range is an important quantity used to describe an image sensor. Wide/High/Extended dynamic range is often brought forward as an important feature to compare one device to another. The dynamic range of an image sensor is normally given as a single number, which is often insufficient since a single number will not fully describe the dynamic capabilities of the sensor. A camera is ideally based on a sensor that can cope with the dynamic range of the scene. Otherwise it has to sacrifice some part of the available data. For a security camera the latter may be critical since important objects might be hidden in the sacrificed part of the scene. In this paper we compare the dynamic capabilities of some image sensors utilizing a visual tool. The comparison is based on the use case, common in surveillance, where low contrast objects may appear in any part of a scene that through its uneven illumination, span a high dynamic range. The investigation is based on real sensor data that has been measured in our lab and a synthetic test scene is used to mimic the low contrast objects. With this technique it is possible to compare sensors with different intrinsic dynamic properties as well as some capture techniques used to create an effect of increased dynamic range.

  5. Controls of picophytoplankton abundance and composition in a highly dynamic marine system, the Northern Alboran Sea (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Amorim, Ana L.; León, Pablo; Mercado, Jesús M.; Cortés, Dolores; Gómez, Francisco; Putzeys, Sebastien; Salles, Soluna; Yebra, Lidia

    2016-06-01

    The Alboran Sea is a highly dynamic basin which exhibits a high spatio-temporal variability of hydrographic structures (e.g. fronts, gyres, coastal upwellings). This work compares the abundance and composition of picophytoplankton observed across the northern Alboran Sea among eleven cruises between 2008 and 2012 using flow cytometry. We evaluate the seasonal and longitudinal variability of picophytoplankton on the basis of the circulation regimes at a regional scale and explore the presence of cyanobacteria ecotypes in the basin. The maximal abundances obtained for Prochlorococcus, Synechococcus and picoeukaryotes (12.7 × 104, 13.9 × 104 and 8.6 × 104 cells mL- 1 respectively) were consistent with those reported for other adjacent marine areas. Seasonal changes in the abundance of the three picophytoplankton groups were highly significant although they did not match the patterns described for other coastal waters. Higher abundances of Prochlorococcus were obtained in autumn-winter while Synechococcus and picoeukaryotes exhibited a different seasonal abundance pattern depending on the sector (e.g. Synechococcus showed higher abundance in summer in the west sector and during winter in the eastern study area). Additionally, conspicuous longitudinal gradients were observed for Prochlorococcus and Synechococcus, with Prochlorococcus decreasing from west to east and Synechococcus following the opposite pattern. The analysis of environmental variables (i.e. temperature, salinity and inorganic nutrients) and cell abundances indicates that Prochlorococcus preferred high salinity and nitrate to phosphate ratio. On the contrary, temperature did not seem to play a role in Prochlorococcus distribution as it was numerically important during the whole seasonal cycle. Variability in Synechococcus abundance could not be explained by changes in any environmental variable suggesting that different ecotypes were sampled during the surveys. In particular, our data would indicate

  6. Reference Ranges & What They Mean

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Reference Ranges and What They Mean Share this page: Was this page helpful? Overview | Reference range defined | Where are the reference ranges? | Limits ...

  7. Pulse spreading and range correction analysis for satellite laser ranging

    NASA Technical Reports Server (NTRS)

    Schwartz, Jon A.

    1990-01-01

    The pulse spreading resulting from light detection and ranging measurements of the range to earth-orbiting satellites is described. An analysis quantifying this pulse spreading and the calculation of corrections to be applied to the lidar range determination of satellites is detailed.

  8. Pulse spreading and range correction analysis for satellite laser ranging.

    PubMed

    Schwartz, J A

    1990-09-01

    The pulse spreading resulting from light detection and ranging measurements of the range to earth-orbiting satellites is described. An analysis quantifying this pulse spreading and the calculation of corrections to be applied to the lidar range determination of satellites is detailed. PMID:20567459

  9. Sequential ranging: How it works

    NASA Technical Reports Server (NTRS)

    Baugh, Harold W.

    1993-01-01

    This publication is directed to the users of data from the Sequential Ranging Assembly (SRA), and to others who have a general interest in range measurements. It covers the hardware, the software, and the processes used in acquiring range data; it does not cover analytical aspects such as the theory of modulation, detection, noise spectral density, and other highly technical subjects. In other words, it covers how ranging is done, but not the details of why it works. The publication also includes an appendix that gives a brief discussion of PN ranging, a capability now under development.

  10. Ranging Behaviour of Commercial Free-Range Laying Hens.

    PubMed

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-01-01

    In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources). These were: apron (0-10 m from shed normally without cover or other enrichments); enriched belt (10-50 m from shed where resources such as manmade cover, saplings and dust baths were provided); and outer range (beyond 50 m from shed with no cover and mainly grass pasture). Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND) of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range areas tend to be

  11. The lunar laser ranging experiment.

    NASA Technical Reports Server (NTRS)

    Bender, P. L.; Currie, D. G.; Poultney, S. K.; Dicke, R. H.; Eckhardt, D. H.; Kaula, W. M.; Mulholland, J. D.; Plotkin, H. H.; Silverberg, E. C.; Faller, J. E.

    1973-01-01

    The scientific objectives achievable through high-accuracy range measurements to lunar retroreflectors are considered. A specific study of design questions related to the operation of retroreflectors on the lunar surface indicated that a reflector panel containing a number of solid fused silica corner reflectors would be capable of maintaining essentially diffraction limited performance under direct solar illumination. Initial Apollo 11 observations are discussed together with the installation of additional lunar retroreflectors in connection with the Luna 17, Apollo 14, Apollo 15, and Luna 21 missions. Range measurements at the McDonald Observatory are considered along with new results from lunar range data, and prospects regarding future lunar ranging stations.

  12. Range Restriction and Attenuation Corrections.

    ERIC Educational Resources Information Center

    Mumford, Michael D.; Mendoza, Jorge L.

    The present paper reviews the techniques commonly used to correct an observed correlation coefficient for the simultaneous influence of attenuation and range restriction effects. It is noted that the procedure which is currently in use may be somewhat biased because it treats range restriction and attenuation as independent restrictive influences.…

  13. Institutional Long-Range Planning.

    ERIC Educational Resources Information Center

    Bolin, John G.

    This booklet presents a general outline for conducting a long-range planning study that can be adapted for use by any institution of higher education. The basic components of an effective long-range plan should include: (1) purposes of the plan, which define the scope of the study and provide the setting in which it will be initiated; (2) a set of…

  14. Extended range chemical sensing apparatus

    DOEpatents

    Hughes, Robert C.; Schubert, W. Kent

    1994-01-01

    An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.

  15. Extended range chemical sensing apparatus

    DOEpatents

    Hughes, R.C.; Schubert, W.K.

    1994-01-18

    An apparatus is described for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy. 6 figures.

  16. Ranging Behaviour of Commercial Free-Range Laying Hens

    PubMed Central

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-01-01

    Simple Summary Commercial free-range production has become a significant sector of the fresh egg market due to legislation banning conventional cages and consumer preference for products perceived as welfare friendly, as access to outdoor range can lead to welfare benefits such as greater freedom of movement and enhanced behavioural opportunities. This study investigated dispersal patterns, feather condition and activity of laying hens in three distinct zones of the range area; the apron area near shed; enriched zone 10–50 m from shed; and outer range beyond 50 m, in six flocks of laying hens under commercial free-range conditions varying in size between 4000 and 24,000 hens. Each flock was visited for four days to record number of hens in each zone, their behaviour, feather condition and nearest neighbour distances (NND), as well as record temperature and relative humidity during the visit. Temperature and relative humidity varied across the study period in line with seasonal variations and influenced the use of range with fewer hens out of shed as temperature fell or relative humidity rose. On average, 12.5% of the hens were observed on the range and most of these hens were recorded in the apron zone as hen density decreased rapidly with increasing distance from the shed. Larger flocks appeared to have a lower proportion of hens on range. The hens used the range more in the early morning followed by a progressive decrease through to early afternoon. The NND was greatest in the outer range and decreased towards the shed. Feather condition was generally good and hens observed in the outer range had the best overall feather condition. Standing, pecking, walking and foraging were the most commonly recorded behaviours and of these, standing occurred most in the apron whereas walking and foraging behaviours were recorded most in the outer range. This study supported the findings of previous studies that reported few hens in the range and greater use of areas closer

  17. [Close-range retinoscopy using integrated optic range finding].

    PubMed

    Kulnig, W

    1983-12-01

    A new type of retinoscope is described which permits all the theoretical advantages of close-range retinoscopy to be exploited in practice thanks to an integrated rangefinder which employs the coincident-image principle. PMID:6668884

  18. Range indices of geomagnetic activity

    USGS Publications Warehouse

    Stuart, W.F.; Green, A.W., Jr.

    1988-01-01

    The simplest index of geomagnetic activity is the range in nT from maximum to minimum value of the field in a given time interval. The hourly range R was recommended by IAGA for use at observatories at latitudes greater than 65??, but was superceded by AE. The most used geomagnetic index K is based on the range of activity in a 3 h interval corrected for the regular daily variation. In order to take advantage of real time data processing, now available at many observatories, it is proposed to introduce a 1 h range index and also a 3 h range index. Both will be computed hourly, i.e. each will have a series of 24 per day, the 3 h values overlapping. The new data will be available as the range (R) of activity in nT and also as a logarithmic index (I) of the range. The exponent relating index to range in nT is based closely on the scale used for computing K values. The new ranges and range indices are available, from June 1987, to users in real time and can be accessed by telephone connection or computer network. Their first year of production is regarded as a trial period during which their value to the scientific and commercial communities will be assessed, together with their potential as indicators of regional and global disturbances' and in which trials will be conducted into ways of eliminating excessive bias at quiet times due to the rate of change of the daily variation field. ?? 1988.

  19. Foraging optimally for home ranges

    USGS Publications Warehouse

    Mitchell, Michael S.; Powell, Roger A.

    2012-01-01

    Economic models predict behavior of animals based on the presumption that natural selection has shaped behaviors important to an animal's fitness to maximize benefits over costs. Economic analyses have shown that territories of animals are structured by trade-offs between benefits gained from resources and costs of defending them. Intuitively, home ranges should be similarly structured, but trade-offs are difficult to assess because there are no costs of defense, thus economic models of home-range behavior are rare. We present economic models that predict how home ranges can be efficient with respect to spatially distributed resources, discounted for travel costs, under 2 strategies of optimization, resource maximization and area minimization. We show how constraints such as competitors can influence structure of homes ranges through resource depression, ultimately structuring density of animals within a population and their distribution on a landscape. We present simulations based on these models to show how they can be generally predictive of home-range behavior and the mechanisms that structure the spatial distribution of animals. We also show how contiguous home ranges estimated statistically from location data can be misleading for animals that optimize home ranges on landscapes with patchily distributed resources. We conclude with a summary of how we applied our models to nonterritorial black bears (Ursus americanus) living in the mountains of North Carolina, where we found their home ranges were best predicted by an area-minimization strategy constrained by intraspecific competition within a social hierarchy. Economic models can provide strong inference about home-range behavior and the resources that structure home ranges by offering falsifiable, a priori hypotheses that can be tested with field observations.

  20. Space-Based Telemetry And Range Safety Flight Demonstration #1

    NASA Technical Reports Server (NTRS)

    Demspm. Erol; Valencia, Lisa M.; Simpson, James C.; Whiteman, Donald E.; Bundick, Steven N.; Wampler, David; Birr, Richard

    2004-01-01

    The basic ability of STARS to maintain a satellite communications link with TDRSS satellites during dynamic aircraft flights was successfully demonstrated during FD 1. The Range Safety and Range User systems' link margins were measured. The ability to acquire/reacquire and maintain lock between a high-dynamic vehicle and a satellite-based system was demonstrated. The Range Safety system simultaneously received and processed command links from space and ground transmitters and provided near real-time Range Safety telemetry to DFRC, which then sent it in near real time to KSC, GSFC, and WFF for monitoring. The GPS receiver maintained track except during extremely dynamic maneuvers. The Range User system sent data at three different data rates. There were excellent cooperation and support from the different Centers, contractors, and Ranges. A large amount of data was recorded and extensive post-flight analysis was performed. The Range User TDRSS link margin met or exceeded the predicted performance at three different data rates. The Range Safety launch-head link margins generally agreed with the predicted performance. The UPS positions and velocities agreed with those from tracking radar to within about 20 m and a few rn/s. The link margins for the Range Safety TDRSS telemetry link were less than expected. The link margin for one TDRSS command link LPT channel was occasionally much less than the other. Additional post-flight testing has yet to identify the root causes of these results. There were many lessons learned from this first set of test flights. The most important one is that more time and testing are needed for each step to deal with the inevitable problems. It is vital that these lessons be among the primary areas of study that will carry over from FD#1 to FD#2, which is currently scheduled for early FY05 at DFRC and will use a specially designed Ku-band phased array antenna for the Range User system. The next series of flight demonstrations scheduled for

  1. Home range analysis using a mechanistic home range model

    SciTech Connect

    Moorcroft, P.R. . Dept. of Ecology and Evolutionary Biology); Lewis, M.A. . Dept. of Mathematics) Crabtree, R.L. . Dept. of Fish and Wildlife Resources)

    1999-07-01

    The traditional models used to characterize animal home ranges have no mechanistic basis underlying their descriptions of space use, and as a result, the analysis of animal home ranges has primarily been a descriptive endeavor. In this paper, the authors characterize coyote (Canis latrans) home range patterns using partial differential equations for expected space use that are formally derived from underlying descriptions of individual movement behavior. To the authors' knowledge, this is the first time that mechanistic models have been used to characterize animal home ranges. The results provide empirical support for a model formulation of movement response to scent marks, and suggest that having relocation data for individuals in adjacent groups is necessary to capture the spatial arrangement of home range boundaries. The authors then show how the model fits can be used to obtain predictions for individual movement and scent marking behavior and to predict changes in home range patterns. More generally, the findings illustrate how mechanistic models permit the development of a predictive theory for the relationship between movement behavior and animal spatial distribution.

  2. Streak camera dynamic range optimization

    SciTech Connect

    Wiedwald, J.D.; Lerche, R.A.

    1987-09-01

    The LLNL optical streak camera is used by the Laser Fusion Program in a wide range of applications. Many of these applications require a large recorded dynamic range. Recent work has focused on maximizing the dynamic range of the streak camera recording system. For our streak cameras, image intensifier saturation limits the upper end of the dynamic range. We have developed procedures to set the image intensifier gain such that the system dynamic range is maximized. Specifically, the gain is set such that a single streak tube photoelectron is recorded with an exposure of about five times the recording system noise. This ensures detection of single photoelectrons, while not consuming intensifier or recording system dynamic range through excessive intensifier gain. The optimum intensifier gain has been determined for two types of film and for a lens-coupled CCD camera. We have determined that by recording the streak camera image with a CCD camera, the system is shot-noise limited up to the onset of image intensifier nonlinearity. When recording on film, the film determines the noise at high exposure levels. There is discussion of the effects of slit width and image intensifier saturation on dynamic range. 8 refs.

  3. The eclipse of species ranges.

    PubMed

    Hemerik, Lia; Hengeveld, Rob; Lippe, Ernst

    2006-01-01

    This paper distinguishes four recognisably different geographical processes in principle causing species to die out. One of these processes, the one we dub "range eclipse", holds that one range expands at the expense of another one, thereby usurping it. Channell and Lomolino (2000a, Journal of Biogeography 27: 169-179; 2000b, Nature 403: 84-87; see also Lomolino and Channell, 1995, Journal of Mammalogy 76: 335-347) measured the course of this process in terms of the proportion of the total range remaining in its original centre, thereby essentially assuming a homogeneous distribution of animals over the range. However, part of their measure seems mistaken. By giving a general, analytical formulation of eclipsing ranges, we estimate the exact course of this process. Also, our formulation does not partition a range into two spatially equal parts, its core and its edge, but it assumes continuity. For applying this model to data on the time evolution of species, individual time series should be available for each of them. For practical purposes we give an alternative way of plotting and interpreting such time series. Our approach, being more sensitive than Channell and Lomolino's, gives a less optimistic indication of range eclipses than theirs once these have started. PMID:17318329

  4. Alternative wavelengths for laser ranging

    NASA Technical Reports Server (NTRS)

    Hamal, Karel

    1993-01-01

    The following are considered to be necessary to accomplish multicolor laser ranging: the nature of the atmospheric dispersion and absorption, the satellite/lunar/ground retro-array characteristics, and ground/satellite ranging machine performance. The energy balance and jitter budget have to be considered as well. It is concluded that the existing satellite/laser retroreflectors seem inadequate for future experiments. The Raman Stokes/Anti-Stokes (0.68/0.43 micron) plus solid state detector appear to be promising instrumentation that satisfy the ground/satellite and satellite/ground ranging machine requirements on the precision, compactness, and data processing.

  5. GPS test range mission planning

    NASA Astrophysics Data System (ADS)

    Roberts, Iris P.; Hancock, Thomas P.

    The principal features of the Test Range User Mission Planner (TRUMP), a PC-resident tool designed to aid in deploying and utilizing GPS-based test range assets, are reviewed. TRUMP features time history plots of time-space-position information (TSPI); performance based on a dynamic GPS/inertial system simulation; time history plots of TSPI data link connectivity; digital terrain elevation data maps with user-defined cultural features; and two-dimensional coverage plots of ground-based test range assets. Some functions to be added during the next development phase are discussed.

  6. The dynamic range of LZ

    NASA Astrophysics Data System (ADS)

    Yin, J.

    2016-02-01

    The electronics of the LZ experiment, the 7-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), is designed to permit studies of physics where the energies deposited range from 1 keV of nuclear-recoil energy up to 3,000 keV of electron-recoil energy. The system is designed to provide a 70% efficiency for events that produce three photoelectrons in the photomultiplier tubes (PMTs). This corresponds approximately to the lowest energy threshold achievable in multi-tonne time-projection chambers, and drives the noise specifications for the front end. The upper limit of the LZ dynamic range is defined to accommodate the electroluminescence (S2) signals. The low-energy channels of the LZ amplifiers provide the dynamic range required for the tritium and krypton calibrations. The high-energy channels provide the dynamic range required to measure the activated Xe lines.

  7. Intentionally Short Range Communications (ISRC)

    NASA Astrophysics Data System (ADS)

    Yen, J.; Poirier, P.; Obrien, M. E.; Gibeson, L.

    1993-05-01

    This document details the feasibility studies conducted for the Intentionally Short Range Communications (ISRC) project. The short-range limitation arises from the need for low probability of intercept (LPI), low probability of detection (LPD) communication links. The detection of an undecipherable transmission would still provide an enemy with information regarding transmitter location. The technologies being studied are ultraviolet (UV) lamps, UV lasers, infrared (IR) lasers, millimeter waves (MMW), and direct sequence spread spectrum.

  8. Analysis and Processing the 3D-Range-Image-Data for Robot Monitoring

    NASA Astrophysics Data System (ADS)

    Kohoutek, Tobias

    2008-09-01

    Industrial robots are commonly used for physically stressful jobs in complex environments. In any case collisions with heavy and high dynamic machines need to be prevented. For this reason the operational range has to be monitored precisely, reliably and meticulously. The advantage of the SwissRanger® SR-3000 is that it delivers intensity images and 3D-information simultaneously of the same scene that conveniently allows 3D-monitoring. Due to that fact automatic real time collision prevention within the robots working space is possible by working with 3D-coordinates.

  9. NASA Satellite Laser Ranging Network

    NASA Technical Reports Server (NTRS)

    Carter, David L.

    2004-01-01

    I will be participating in the International Workshop on Laser Ranging. I will be presenting to the International Laser Ranging Service (ILRS) general body meeting on the recent accomplishments and status of the NASA Satellite Laser Ranging (SLR) Network. The recent accomplishments and NASA's future plans will be outlined and the benefits to the scientific community will be addressed. I am member of the ILRS governing board, the Missions working group, and the Networks & Engineering working group. I am the chairman of the Missions Working and will be hosting a meeting during the week of the workshop. I will also represent the NASA SLR program at the ILRS governing board and other working group meetings.

  10. APOLLO: millimeter lunar laser ranging

    NASA Astrophysics Data System (ADS)

    Murphy, T. W., Jr.; Adelberger, E. G.; Battat, J. B. R.; Hoyle, C. D.; Johnson, N. H.; McMillan, R. J.; Stubbs, C. W.; Swanson, H. E.

    2012-09-01

    Lunar laser ranging (LLR) has for decades stood at the forefront of tests of gravitational physics, including tests of the equivalence principle (EP). Current LLR results on the EP achieve a sensitivity of Δa/a ≈ 10-13 based on few-centimeter data/model fidelity. A recent push in LLR, called APOLLO (the Apache Point Observatory Lunar Laser-ranging Operation) produces millimeter-quality data. This paper demonstrates the few-millimeter range precision achieved by APOLLO, leading to an expectation that LLR will be able to extend EP sensitivity by an order-of-magnitude to Δa/a ˜ 10-14, once modeling efforts improve to this level.

  11. Laser system of extended range

    NASA Technical Reports Server (NTRS)

    Lehr, C. G.

    1972-01-01

    A pulsed laser system was developed for range measurements from the earth to retroreflecting satellites at distances up to that of the moon. The system has a transportable transmitter unit that can be moved from one location to another. This unit consists of a 0.2 m coude refractor and a high radiance, neodymium-glass, frequency doubled laser that operates in a single transverse mode. It can be used for lunar or distant satellite ranging at any observatory that has a telescope with an aperture diameter of about 1.5 m for the detection of the laser return pulses. This telescope is utilized in the same manner customarily employed for the observation of celestial objects. A special photometric package and the associated electronics are provided for laser ranging.

  12. Wide range magnetic electron spectrograph

    NASA Technical Reports Server (NTRS)

    Coplan, M. A.; Wang, L.-J.; Moore, J. H.; Hoffman, R. A.

    1989-01-01

    An electron spectrogrpah is described that covers electron energies from 400 eV to 200 keV with an energy resolution of 10 percent. This overlaps the range of electrostatic deflection devices at low energy and solid state detectors at high energy. The spectrograph uses magnetic deflection of the electrons to achieve energy separation and images the full range of energies on a single plane. The magnetic circuit uses the fringing field of two axially located magnets to attain the large energy range. Six separate electron beams can be dispersed in the field, each entering the circuit from a different angle. This is a particular advantage when measuring plasma electron three-dimensional velocity distributions. The angular response of the instrument is particularly favorable and the stray magnetic field is sufficiently low to meet spacecraft requirements.

  13. The Dynamic Range of LZ

    NASA Astrophysics Data System (ADS)

    Yin, Jun; LZ Collaboration

    2015-10-01

    The electronics of the LZ experiment, the 7-ton dark matter detector to be installed at the Sanford Underground Research Facility (SURF), is designed to provide a 70% efficiency for events that produce three photoelectrons in the photomultiplier tubes (PMTs). This corresponds approximately to the lowest energy threshold achievable in such a detector, and drives the noise specifications for the front end. The upper limit of the LZ dynamic range is defined by the electroluminescence (S2) signals. The low-energy channels of the LZ amplifiers provide the dynamic range required for the tritium and krypton calibrations. The high-energy channels provide the dynamic range required to measure the activated Xe lines. S2 signals induced by alpha particles from radon decay will saturate one or more channels of the top PMT array but techniques are being developed to recover the information lost due to saturation. This work was supported by the Department of Energy, Grant DE-SC0006605.

  14. RANGE INCREASER FOR PNEUMATIC GAUGES

    DOEpatents

    Fowler, A.H.; Seaborn, G.B. Jr.

    1960-09-27

    An improved pneumatic gage is offered in which the linear range has been increased without excessive air consumption. This has been accomplished by providing an expansible antechamber connected to the nozzle of the gage so that the position of the nozzle with respect to the workpiece is varied automatically by variation in pressure within the antechamber. This arrangement ensures that the nozzle-to-workpiece clearance is maintained within certain limits, thus obtaining a linear relation of air flow to nozzle-to-workpiece clearance over a wider range.

  15. In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

    NASA Astrophysics Data System (ADS)

    Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

    2014-02-01

    The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

  16. Back Home on the Range.

    ERIC Educational Resources Information Center

    Breining, Greg

    1992-01-01

    Presents the history of the buffalo's demise and reemergence in the United States and Canada. Discusses the problems facing herds today caused by a small genetic pool, disease, range concerns, lack of predation, and culling. Points out the benefits of buffalo raising as compared to cattle raising, including the marketing advantages. (MCO)

  17. Anatomy of a Mountain Range.

    ERIC Educational Resources Information Center

    Chew, Berkeley

    1993-01-01

    Provides written tour of Colorado Rockies along San Juan Skyway in which the geological features and formation of the mountain range is explored. Discusses evidence of geologic forces and products such as plate tectonic movement and the Ancestral Rockies; subduction and the Laramide Orogeny; volcanism and calderas; erosion, faulting, land…

  18. Long range fast tool servo

    NASA Astrophysics Data System (ADS)

    Moorefield, G. M., II; Dow, Thomas A.; Falter, Karl J.; Ro, Paul I.

    1993-05-01

    The PEC's MAC 100 Fast Tool Servo (FTS) System has demonstrated the efficacy of fabricating off-axis parabolic segments on axis by utilizing a fast tool motion to machine non-rotationally symmetric surfaces. The key to this technique was a servo for the tool motion that had a high-bandwidth coupled with a small range of motion. The Keck telescope, with its thirty-six (36) 1-meter diameter segments, would have been an excellent application for this technology. Since this technology was not available at the time of construction, each mirror segment was fabricated to its desired shape by loading it to a specified deformed shape and polishing it to a spherical contour, then removing the bending loads to allow the segment to relax to the desired asymmetric shape. If the segments of this optic had been constructed on axis with an FTS, the fabrication of the most extreme segment would have required only about 200 micrometers of non-rotational symmetry. However, the demand for larger displacement actuators is being driven by new applications with nonrotationally symmetric components in the millimeter range. This report describes the search for a suitable actuator for a long range fast tool servo system that would allow the fabrication of non-rotationally symmetric optical surfaces with a 1 mm range of servo motion. To allow cost-effective machining of these surfaces, the actuator must also possess a 50 Hz bandwidth (minimum) and 25 nanometer resolution.

  19. About White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Information on the White Sands Missile Range is given in viewgraph form. Navy programs, test sites, rocket programs, research rockets' booster capacity, current boost capabilities, ordnance and payload assembly areas, commercial space launch history and agreements, and lead times are among the topics covered.

  20. Wide Dynamic Range CCD Camera

    NASA Astrophysics Data System (ADS)

    Younse, J. M.; Gove, R. J.; Penz, P. A.; Russell, D. E.

    1984-11-01

    A liquid crystal attenuator (LCA) operated as a variable neutral density filter has been attached to a charge-coupled device (CCD) imager to extend the dynamic range of a solid-state TV camera by an order of magnitude. Many applications are best served by a camera with a dynamic range of several thousand. For example, outside security systems must operate unattended with "dawn-to-dusk" lighting conditions. Although this can be achieved with available auto-iris lens assemblies, more elegant solutions which provide the small size, low power, high reliability advantages of solid state technology are now available. This paper will describe one such unique way of achieving these dynamic ranges using standard optics by making the CCD imager's glass cover a controllable neutral density filter. The liquid crystal attenuator's structure and theoretical properties for this application will be described along with measured transmittance. A small integrated TV camera which utilizes a "virtual-phase" CCD sensor coupled to a LCA will be described and test results for a number of the camera's optical and electrical parameters will be given. These include the following camera parameters: dynamic range, Modulation Transfer Function (MTF), spectral response, and uniformity. Also described will be circuitry which senses the ambient scene illuminance and automatically provides feedback signals to appropriately adjust the transmittance of the LCA. Finally, image photographs using this camera, under various scene illuminations, will be shown.

  1. Mobile Lunar Laser Ranging Station

    ERIC Educational Resources Information Center

    Intellect, 1977

    1977-01-01

    Harlan Smith, chairman of the University of Texas's Astronomy Department, discusses a mobile lunar laser ranging station which could help determine the exact rates of movement between continents and help geophysicists understand earthquakes. He also discusses its application for studying fundamental concepts of cosmology and physics. (Editor/RK)

  2. Contrails reduce daily temperature range.

    PubMed

    Travis, David J; Carleton, Andrew M; Lauritsen, Ryan G

    2002-08-01

    The potential of condensation trails (contrails) from jet aircraft to affect regional-scale surface temperatures has been debated for years, but was difficult to verify until an opportunity arose as a result of the three-day grounding of all commercial aircraft in the United States in the aftermath of the terrorist attacks on 11 September 2001. Here we show that there was an anomalous increase in the average diurnal temperature range (that is, the difference between the daytime maximum and night-time minimum temperatures) for the period 11-14 September 2001. Because persisting contrails can reduce the transfer of both incoming solar and outgoing infrared radiation and so reduce the daily temperature range, we attribute at least a portion of this anomaly to the absence of contrails over this period. PMID:12167846

  3. Ultrasonic ranging for the oculometer

    NASA Technical Reports Server (NTRS)

    Guy, W. J.

    1981-01-01

    Ultrasonic tracking techniques are investigated for an oculometer. Two methods are reported in detail. The first is based on measurements of time from the start of a transmit burst to a received echo. Knowing the sound velocity, distance can be calculated. In the second method, a continuous signal is transmitted. Target movement causes phase shifting of the echo. By accumulating these phase shifts, tracking from a set point can be achieved. Both systems have problems with contoured targets, but work well on flat plates and the back of a human head. Also briefly reported is an evaluation of an ultrasonic ranging system. Interface circuits make this system compatible with the echo time design. While the system is consistently accurate, it has a beam too narrow for oculometer use. Finally, comments are provided on a tracking system using the Doppler frequency shift to give range data.

  4. Short-range communication system

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  5. Propagator for finite range potentials

    SciTech Connect

    Cacciari, Ilaria; Moretti, Paolo

    2006-12-15

    The Schroedinger equation in integral form is applied to the one-dimensional scattering problem in the case of a general finite range, nonsingular potential. A simple expression for the Laplace transform of the transmission propagator is obtained in terms of the associated Fredholm determinant, by means of matrix methods; the particular form of the kernel and the peculiar aspects of the transmission problem play an important role. The application to an array of delta potentials is shown.

  6. Range Expansion of Heterogeneous Populations

    NASA Astrophysics Data System (ADS)

    Reiter, Matthias; Rulands, Steffen; Frey, Erwin

    2014-04-01

    Risk spreading in bacterial populations is generally regarded as a strategy to maximize survival. Here, we study its role during range expansion of a genetically diverse population where growth and motility are two alternative traits. We find that during the initial expansion phase fast-growing cells do have a selective advantage. By contrast, asymptotically, generalists balancing motility and reproduction are evolutionarily most successful. These findings are rationalized by a set of coupled Fisher equations complemented by stochastic simulations.

  7. Range determination for scannerless imaging

    DOEpatents

    Muguira, Maritza Rosa; Sackos, John Theodore; Bradley, Bart Davis; Nellums, Robert

    2000-01-01

    A new method of operating a scannerless range imaging system (e.g., a scannerless laser radar) has been developed. This method is designed to compensate for nonlinear effects which appear in many real-world components. The system operates by determining the phase shift of the laser modulation, which is a physical quantity related physically to the path length between the laser source and the detector, for each pixel of an image.

  8. Range gated strip proximity sensor

    DOEpatents

    McEwan, T.E.

    1996-12-03

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance. 6 figs.

  9. Range gated strip proximity sensor

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance.

  10. Medium Range Forecasts Representation (and Long Range Forecasts?)

    NASA Astrophysics Data System (ADS)

    Vincendon, J.-C.

    2009-09-01

    The progress of the numerical forecasts urges us to interest us in more and more distant ranges. We thus supply more and more forecasts with term of some days. Nevertheless, precautions of use are necessary to give the most reliable and the most relevant possible information. Available in a TV bulletin or on quite other support (Internet, mobile phone), the interpretation and the representation of a medium range forecast (5 - 15 days) must be different from those of a short range forecast. Indeed, the "foresee-ability” of a meteorological phenomenon decreases gradually in the course of the ranges, it decreases all the more quickly that the phenomenon is of small scale. So, at the end of some days, the probability character of a forecast becomes very widely dominating. That is why in Meteo-France the forecasts of D+4 to D+7 are accompanied with a confidence index since around ten years. It is a figure between 1 and 5: the more we approach 5, the more the confidence in the supplied forecast is good. In the practice, an indication is supplied for period D+4 / D+5, the other one for period D+6 / D+7, every day being able to benefit from a different forecast, that is be represented in a independent way. We thus supply a global tendency over 24 hours with less and less precise symbols as the range goes away. Concrete examples will be presented. From now on two years, we also publish forecasts to D+8 / J+9, accompanied with a sign of confidence (" good reliability " or " to confirm "). These two days are grouped together on a single map because for us, the described tendency to this term is relevant on a duration about 48 hours with a spatial scale slightly superior to the synoptic scale. So, we avoid producing more than two zones of types of weather over France and we content with giving an evolution for the temperatures (still, in increase or in decline). Newspapers began to publish this information, it should soon be the case of televisions. It is particularly

  11. High Dynamic Pressure and Strong Northward IMF: Ingredients for a New Type of Ring Current on 21-22 January 2005

    NASA Astrophysics Data System (ADS)

    Kozyra, J. U.; Brandt, P. C.; Evans, D. S.; Fang, X.; Fok, M.; Gonzalez, W. D.; Liemohn, M. W.; Lu, G.; Rastaetter, L.; Ridley, A.; Thomsen, M. F.; Tsurutani, B.

    2009-05-01

    During the 21-22 January 2005 magnetic storm, a highly unusual ring current developed dominantly during northward IMF and high dynamic pressure with minimum pressure-corrected symH less than -100 nT. Early in the storm, a short (less than 1 hour) interval of strong southward IMF produced a brief depression in sym H which had already recovered when the main phase development of the ring current began under northward IMF and sustained high solar wind dynamic pressure. During the ring current development, a hot dense plasma sheet was observed at geosynchronous orbit followed by a cold dense plasma sheet. The movement of these dense plasma sheets through the inner magnetosphere during the high dynamic pressure interval in the solar wind produced the ring current, which began to decay immediately following the end of the cold dense plasma sheet interval. The cross polar cap potential reached a maximum during the interval of strongest southward IMF early in the storm. However, the equatorward edge of the auroral oval (as indicated by the MBI index) moved to lowest latitudes as the hot high-density plasma sheet stretched out the magnetotail. Precipitation of protons and electrons at ring current energies maximized during the peak of the ring current development under northward IMF conditions. A simulation of this magnetic storm event using the BATS-R-US MHD model with an inner magnetosphere module based on the Rice Convection model produces all the main features of this unusual ring current development and, in addition, shows that the solar wind-magnetosphere coupling was different during the hot compared to the cold high density plasma sheet intervals. We present a comparison between observations and model results and explore the processes responsible for this unusual ring current and its decay.

  12. Wide-range CCD spectrometer

    NASA Astrophysics Data System (ADS)

    Sokolova, Elena A.; Reyes Cortes, Santiago D.

    1996-08-01

    The utilization of wide range spectrometers is a very important feature for the design of optical diagnostics. This paper describes an innovative approach, based on charged coupled device, which allows to analyze different spectral intervals with the same diffraction grating. The spectral interval is varied by changing the position of the entrance slit when the grating is stationary. The optical system can also include a spherical mirror. In this case the geometric position of the mirror is calculated aiming at compensating the first order astigmatism and the meridional coma of the grating. This device is planned to be used in Thomson scattering diagnostic of the TOKAMAK of Instituto Superior Tecnico, Lisbon (ISTTOK).

  13. Short Range Correlations in Nuclei

    SciTech Connect

    L. B. Weinstein

    2006-11-01

    Short range correlations (SRC) are an extremely important part of nuclear structure. They are responsible for the high momentum part of the nuclear wavefunction. Instantaneous densities can significantly exceed the average neutron star density. Recent (e,e[prime]) measurements at Jefferson Lab have shown that SRC are universal in nuclei from deuterium to gold, that the probability of two-nucleon SRC is 5-25%, and that the probability of three-nucleon SRC is less than 1%. Recent (e,e[prime]pn) measurements have measured the SRC probabilities as a function of proton momentum and have measured the joint NN momentum distributions.

  14. Extended-range tiltable micromirror

    DOEpatents

    Allen, James J.; Wiens, Gloria J.; Bronson, Jessica R.

    2009-05-05

    A tiltable micromirror device is disclosed in which a micromirror is suspended by a progressive linkage with an electrostatic actuator (e.g. a vertical comb actuator or a capacitive plate electrostatic actuator) being located beneath the micromirror. The progressive linkage includes a pair of torsion springs which are connected together to operate similar to a four-bar linkage with spring joints. The progressive linkage provides a non-linear spring constant which can allow the micromirror to be tilted at any angle within its range substantially free from any electrostatic instability or hysteretic behavior.

  15. BENTON RANGE ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    McKee, Edwin H.; Rains, Richard L.

    1984-01-01

    On the basis of a mineral survey, two parts of the Benton Range Roadless Area, California are considered to have mineral-resource potential. The central and southern part of the roadless area, near several nonoperating mines, has a probable potential for tungsten and gold-silver mineralization in tactite zones. The central part of the area has a substantiated resource potential for gold and silver in quartz veins. Detailed mapping and geochemical sampling for tungsten, gold, and silver in the central and southern part of the roadless area might indicate targets for shallow drilling exploration.

  16. Long-range atmospheric predictability

    NASA Astrophysics Data System (ADS)

    Reichler, Thomas Josef

    This study investigated the prospects and limits of global atmospheric predictability on the long range (beyond 2 weeks). Forecasting the atmosphere at this range is very challenging since elements of both weather and climate prediction enter the problem. The basic questions were: (1) how large is long-range predictability with perfect model and data; (2) how sensitive is such predictability to uncertainties in model and data; (3) which atmospheric processes are related to this predictability? These questions were answered through numerical experiments with an atmospheric general circulation model which is forced with different combinations of initial and boundary conditions. In particular, four tasks were accomplished: First, temporal variations of predictability and its relationship to initial and boundary conditions were examined. On average, initial conditions dominated predictability for the first 4 weeks, improved predictability for 6 weeks, and influenced predictability for 8 weeks. These time scales varied with season, region, and strength of the external forcing. Second, the global 3-dimensional structure of predictability was examined. Boundary forcing dominated over the tropics, and over the two main teleconnection regions in the North and South Pacific. Initial conditions influenced predictability almost everywhere, in particular when the external forcing was weak. This was mostly related to atmospheric persistence, which in turn was linked to low-frequency variability of major atmospheric modes. Third, predictability in the tropics was investigated for monthly means. Boundary forcing is generally dominating for this time scale, and its quality is crucial. The atmospheric response was strongly asymmetric to SST forcing, which suggests that tropical convection has a positive self-amplifying feedback. Initial conditions were also important, in particular over the Eastern Hemisphere. This was related to strong persistence of the divergent circulation and

  17. Long-range electron transfer

    PubMed Central

    Gray, Harry B.; Winkler, Jay R.

    2005-01-01

    Recent investigations have shed much light on the nuclear and electronic factors that control the rates of long-range electron tunneling through molecules in aqueous and organic glasses as well as through bonds in donor–bridge–acceptor complexes. Couplings through covalent and hydrogen bonds are much stronger than those across van der Waals gaps, and these differences in coupling between bonded and nonbonded atoms account for the dependence of tunneling rates on the structure of the media between redox sites in Ru-modified proteins and protein–protein complexes. PMID:15738403

  18. Live Fire Range Environmental Assessment

    SciTech Connect

    1993-08-01

    The Central Training Academy (CTA) is a DOE Headquarters Organization located in Albuquerque, New Mexico, with the mission to effectively and efficiently educate and train personnel involved in the protection of vital national security interests of DOE. The CTA Live Fire Range (LFR), where most of the firearms and tactical training occurs, is a complex separate from the main campus. The purpose of the proposed action is to expand the LFR to allow more options of implementing required training. The Department of Energy has prepared this Environmental Assessment (EA) for the proposed construction and operation of an expanded Live Fire Range Facility at the Central Training Academy in Albuquerque, New Mexico. Based on the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an environmental impact statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

  19. The Ames Vertical Gun Range

    NASA Technical Reports Server (NTRS)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  20. Range-Measuring Video Sensors

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.; Briscoe, Jeri M.; Corder, Eric L.; Broderick, David

    2006-01-01

    Optoelectronic sensors of a proposed type would perform the functions of both electronic cameras and triangulation- type laser range finders. That is to say, these sensors would both (1) generate ordinary video or snapshot digital images and (2) measure the distances to selected spots in the images. These sensors would be well suited to use on robots that are required to measure distances to targets in their work spaces. In addition, these sensors could be used for all the purposes for which electronic cameras have been used heretofore. The simplest sensor of this type, illustrated schematically in the upper part of the figure, would include a laser, an electronic camera (either video or snapshot), a frame-grabber/image-capturing circuit, an image-data-storage memory circuit, and an image-data processor. There would be no moving parts. The laser would be positioned at a lateral distance d to one side of the camera and would be aimed parallel to the optical axis of the camera. When the range of a target in the field of view of the camera was required, the laser would be turned on and an image of the target would be stored and preprocessed to locate the angle (a) between the optical axis and the line of sight to the centroid of the laser spot.

  1. Range Imaging without Moving Parts

    NASA Technical Reports Server (NTRS)

    Blair, J. Bryan; Scott, V. Stanley, III; Ramos-Izquierdo, Luis

    2008-01-01

    Range-imaging instruments of a type now under development are intended to generate the equivalent of three-dimensional images from measurements of the round-trip times of flight of laser pulses along known directions. These instruments could also provide information on characteristics of targets, including roughnesses and reflectivities of surfaces and optical densities of such semi-solid objects as trees and clouds. Unlike in prior range-imaging instruments based on times of flight along known directions, there would be no moving parts; aiming of the laser beams along the known directions would not be accomplished by mechanical scanning of mirrors, prisms, or other optical components. Instead, aiming would be accomplished by using solid-state devices to switch input and output beams along different fiber-optic paths. Because of the lack of moving parts, these instruments could be extraordinarily reliable, rugged, and long-lasting. An instrument of this type would include an optical transmitter that would send out a laser pulse along a chosen direction to a target. An optical receiver coaligned with the transmitter would measure the temporally varying intensity of laser light reflected from the target to determine the distance and surface characteristics of the target. The transmitter would be a combination of devices for generating precise directional laser illumination. It would include a pulsed laser, the output of which would be coupled into a fiber-optic cable with a fan-out and solid-state optical switches that would enable switching of the laser beam onto one or more optical fibers terminated at known locations in an array on a face at the focal plane of a telescope. The array would be imaged by the telescope onto the target space. The receiver optical system could share the aforementioned telescope with the transmitter or could include a separate telescope aimed in the same direction as that of the transmitting telescope. In either case, light reflected

  2. Wind dynamic range video camera

    NASA Technical Reports Server (NTRS)

    Craig, G. D. (Inventor)

    1985-01-01

    A television camera apparatus is disclosed in which bright objects are attenuated to fit within the dynamic range of the system, while dim objects are not. The apparatus receives linearly polarized light from an object scene, the light being passed by a beam splitter and focused on the output plane of a liquid crystal light valve. The light valve is oriented such that, with no excitation from the cathode ray tube, all light is rotated 90 deg and focused on the input plane of the video sensor. The light is then converted to an electrical signal, which is amplified and used to excite the CRT. The resulting image is collected and focused by a lens onto the light valve which rotates the polarization vector of the light to an extent proportional to the light intensity from the CRT. The overall effect is to selectively attenuate the image pattern focused on the sensor.

  3. Wide Range SET Pulse Measurement

    NASA Technical Reports Server (NTRS)

    Shuler, Robert L.; Chen, Li

    2012-01-01

    A method for measuring a wide range of SET pulses is demonstrated. Use of dynamic logic, faster than ordinary CMOS, allows capture of short pulses. A weighted binning of SET lengths allows measurement of a wide range of pulse lengths with compact circuitry. A pulse-length-conservative pulse combiner tree routes SETs from combinational logic to the measurement circuit, allowing SET measurements in circuits that cannot easily be arranged in long chains. The method is applied to add-multiplex combinational logic, and to an array of NFET routing switches, at .35 micron. Pulses are captured in a chain of Domino Logic AND gates. Propagation through the chain is frozen on the trailing edge by dropping low the second "enable" input to the AND gates. Capacitive loading is increased in the latter stages to create an approximately logarithmic weighted binning, so that a broad range of pulse lengths can be captured with a 10 stage capture chain. Simulations show pulses can be captured which are 1/5th the length of those typically captured with leading edge triggered latch methods, and less than the length of those captured with a trailing edge latch method. After capture, the pulse pattern is transferred to an SEU protected shift register for readout. 64 instances of each of two types of logic are used as targets. One is a full adder with a 4 to 1 mux on its inputs. The other is a 4 x 4 NFET routing matrix. The outputs are passed through buffered XNOR comparators to identify pulses, which are merged in a buffered not-nand (OR) tree designed to avoid pulse absorption as much as possible. The output from each of the two test circuits are input into separate pulse measurement circuits. Test inputs were provided so that the circuit could be bench tested and calibrated. A third SET measurement circuit with no inputs was used to judge the contribution from direct hits on the measurement circuit. Heavy ions were used with an LET range from 12 to 176. At LET of 21 and below, the very

  4. Space - The long range future

    NASA Technical Reports Server (NTRS)

    Von Puttkamer, J.

    1985-01-01

    Space exploration goals for NASA in the year 2000 time frame are examined. A lunar base would offer the opportunity for continuous earth viewing, further cosmogeochemical exploration and rudimentary steps at self-sufficiency in space. The latter two factors are also compelling reasons to plan a manned Mars base. Furthermore, competition and cooperation in a Mars mission and further interplanetary exploration is an attractive substitute for war. The hardware requirements for various configurations of Mars missions are briefly addressed, along with other, unmanned missions to the asteroid belt, Mercury, Venus, Jupiter and the moons of Jupiter and Saturn. Finally, long-range technological requirements for providing adequate living/working facilities for larger human populations in Space Station environments are summarized.

  5. Extended range tankless water heater

    SciTech Connect

    Harris, J.A.

    1993-04-18

    In this research program, a laboratory test facility was built for the purpose of testing a gas-fired water heating appliance. This test facility can be used to examine the important performance characteristics of efficiency, dynamic response, and quality of combustion. An innovative design for a tankless water heater was built and then tested to determine its performance characteristics. This unit was tested over a 5:1 range in input (20,000 to 100,000 btuh heat input). The unit was then configured as a circulating hot water boiler, and a specially designed heat exchanger was used with it to generate domestic hot water. This unit was also tested, and was found to offer performance advantages with regard to low flow and temperature stability.

  6. Understanding synthesis imaging dynamic range

    NASA Astrophysics Data System (ADS)

    Braun, R.

    2013-03-01

    We develop a general framework for quantifying the many different contributions to the noise budget of an image made with an array of dishes or aperture array stations. Each noise contribution to the visibility data is associated with a relevant correlation timescale and frequency bandwidth so that the net impact on a complete observation can be assessed when a particular effect is not captured in the instrumental calibration. All quantities are parameterised as function of observing frequency and the visibility baseline length. We apply the resulting noise budget analysis to a wide range of existing and planned telescope systems that will operate between about 100 MHz and 5 GHz to ascertain the magnitude of the calibration challenges that they must overcome to achieve thermal noise limited performance. We conclude that calibration challenges are increased in several respects by small dimensions of the dishes or aperture array stations. It will be more challenging to achieve thermal noise limited performance using 15 m class dishes rather than the 25 m dishes of current arrays. Some of the performance risks are mitigated by the deployment of phased array feeds and more with the choice of an (alt,az,pol) mount, although a larger dish diameter offers the best prospects for risk mitigation. Many improvements to imaging performance can be anticipated at the expense of greater complexity in calibration algorithms. However, a fundamental limitation is ultimately imposed by an insufficient number of data constraints relative to calibration variables. The upcoming aperture array systems will be operating in a regime that has never previously been addressed, where a wide range of effects are expected to exceed the thermal noise by two to three orders of magnitude. Achieving routine thermal noise limited imaging performance with these systems presents an extreme challenge. The magnitude of that challenge is inversely related to the aperture array station diameter.

  7. Expansion-based passive ranging

    NASA Technical Reports Server (NTRS)

    Barniv, Yair

    1993-01-01

    A new technique of passive ranging which is based on utilizing the image-plane expansion experienced by every object as its distance from the sensor decreases is described. This technique belongs in the feature/object-based family. The motion and shape of a small window, assumed to be fully contained inside the boundaries of some object, is approximated by an affine transformation. The parameters of the transformation matrix are derived by initially comparing successive images, and progressively increasing the image time separation so as to achieve much larger triangulation baseline than currently possible. Depth is directly derived from the expansion part of the transformation. To a first approximation, image-plane expansion is independent of image-plane location with respect to the focus of expansion (FOE) and of platform maneuvers. Thus, an expansion-based method has the potential of providing a reliable range in the difficult image area around the FOE. In areas far from the FOE the shift parameters of the affine transformation can provide more accurate depth information than the expansion alone, and can thus be used similarly to the way they were used in conjunction with the Inertial Navigation Unit (INU) and Kalman filtering. However, the performance of a shift-based algorithm, when the shifts are derived from the affine transformation, would be much improved compared to current algorithms because the shifts - as well as the other parameters - can be obtained between widely separated images. Thus, the main advantage of this new approach is that, allowing the tracked window to expand and rotate, in addition to moving laterally, enables one to correlate images over a very long time span which, in turn, translates into a large spatial baseline - resulting in a proportionately higher depth accuracy.

  8. Expansion-based passive ranging

    NASA Technical Reports Server (NTRS)

    Barniv, Yair

    1993-01-01

    This paper describes a new technique of passive ranging which is based on utilizing the image-plane expansion experienced by every object as its distance from the sensor decreases. This technique belongs in the feature/object-based family. The motion and shape of a small window, assumed to be fully contained inside the boundaries of some object, is approximated by an affine transformation. The parameters of the transformation matrix are derived by initially comparing successive images, and progressively increasing the image time separation so as to achieve much larger triangulation baseline than currently possible. Depth is directly derived from the expansion part of the transformation. To a first approximation, image-plane expansion is independent of image-plane location with respect to the focus of expansion (FOE) and of platform maneuvers. Thus, an expansion-based method has the potential of providing a reliable range in the difficult image area around the FOE. In areas far from the FOE the shift parameters of the affine transformation can provide more accurate depth information than the expansion alone, and can thus be used similarly to the way they have been used in conjunction with the Inertial Navigation Unit (INU) and Kalman filtering. However, the performance of a shift-based algorithm, when the shifts are derived from the affine transformation, would be much improved compared to current algorithms because the shifts--as well as the other parameters--can be obtained between widely separated images. Thus, the main advantage of this new approach is that, allowing the tracked window to expand and rotate, in addition to moving laterally, enables one to correlate images over a very long time span which, in turn, translates into a large spatial baseline resulting in a proportionately higher depth accuracy.

  9. Wide-range voltage modulation

    SciTech Connect

    Rust, K.R.; Wilson, J.M.

    1992-06-01

    The Superconducting Super Collider`s Medium Energy Booster Abort (MEBA) kicker modulator will supply a current pulse to the abort magnets which deflect the proton beam from the MEB ring into a designated beam stop. The abort kicker will be used extensively during testing of the Low Energy Booster (LEB) and the MEB rings. When the Collider is in full operation, the MEBA kicker modulator will abort the MEB beam in the event of a malfunction during the filling process. The modulator must generate a 14-{mu}s wide pulse with a rise time of less than 1 {mu}s, including the delay and jitter times. It must also be able to deliver a current pulse to the magnet proportional to the beam energy at any time during ramp-up of the accelerator. Tracking the beam energy, which increases from 12 GeV at injection to 200 GeV at extraction, requires the modulator to operate over a wide range of voltages (4 kV to 80 kV). A vacuum spark gap and a thyratron have been chosen for test and evaluation as candidate switches for the abort modulator. Modulator design, switching time delay, jitter and pre-fire data are presented.

  10. Front Range of the Rockies

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These MISR images from May 12, 2001 (Terra orbit 7447) include portions of southern Wyoming, central Colorado, and western Nebraska. The top view is from the instrument's vertical-viewing (nadir) camera. The bottom image is a stereo 'anaglyph' generated using data from the nadir and 46-degree-forward cameras. Viewing the anaglyph with red/blue glasses (red filter over your left eye) gives a 3-D effect. To facilitate stereo viewing, the images have been oriented with north at the left. Each image measures 422 kilometers x 213 kilometers.

    The South Platte River enters just to the right of center at the top of the images. It wends its way westward (down), then turns southward (right) where it flows through the city of Denver. Located at the western edge of the Great Plains, Denver is nicknamed the 'Mile High City', a consequence of its 1609-meter (5280-foot) elevation above sea level. It shows up in the imagery as a grayish patch surrounded by numerous agricultural fields to the north and east. Denver is situated just east of the Front Range of the Rocky Mountains, located in the lower right of the images. The Rockies owe their present forms to tectonic uplift and sculpting by millions of years of erosion. Scattered cumulus clouds floating above the mountain peaks are visible in these images, and stand out most dramatically in the 3-D stereo view.

    To the north of Denver, other urban areas included within these images are Boulder, Greeley, Longmont, and Fort Collins, Colorado; Cheyenne and Laramie, Wyoming; and Scottsbluff, Nebraska.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  11. Space Based Range Demonstration and Certification (SBRDC)

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert

    2005-01-01

    This viewgraph presentation describes the development, utilization and testing of technologies for range safety and range user systems. The contents include: 1) Space Based Range (SBR) Goals and Objectives; 2) Today s United States Range; 3) Future Range; 4) Another Vision for the Future Range; 5) STARS Project Goals; 6) STARS Content; 7) STARS Configuration Flight Demonstrations 1 & 2; 8) Spaceport And Range Technologies STARS Objectives and Results; 9) Spaceport And Range Technologies STARS FD2 Objectives; 10) Range Safety Hardware; 11) Range User Hardware; and 12) Past/Future Flight Demo Plans

  12. Pyrotag sequencing of the gut microbiota of the cockroach Shelfordella lateralis reveals a highly dynamic core but only limited effects of diet on community structure.

    PubMed

    Schauer, Christine; Thompson, Claire; Brune, Andreas

    2014-01-01

    Although blattid cockroaches and termites share a common ancestor, their diets are distinctly different. While termites consume a highly specialized diet of lignocellulose, cockroaches are omnivorous and opportunistic feeders. The role of the termite gut microbiota has been studied intensively, but little is known about the cockroach gut microbiota and its function in digestion and nutrition, particularly the adaptation to different diets. Our analyses of the bacterial gut microbiota of the blattid cockroach Shelfordella lateralis combining terminal restriction fragment length polymorphism of their 16S rRNA genes with physiological parameters (microbial metabolites, hydrogen and methane emission) indicated substantial variation between individuals but failed to identify any diet-related response. Subsequent deep-sequencing of the 16S rRNA genes of the colonic gut microbiota of S. lateralis fed either a high- or a low-fiber diet confirmed the absence of bacterial taxa that responded to diet. Instead, we found a small number of abundant phylotypes that were consistently present in all samples and made up half of the community in both diet groups. They varied strongly in abundance between individual samples at the genus but not at the family level. The remaining phylotypes were inconsistently present among replicate batches. Our findings suggest that S. lateralis harbors a highly dynamic core gut microbiota that is maintained even after fundamental dietary shifts, and that any dietary effects on the gut community are likely to be masked by strong individual variations. PMID:24454939

  13. Effect of high hydrostatic pressure and high dynamic pressure on stability and rheological properties of model oil-in-water emulsions

    NASA Astrophysics Data System (ADS)

    Bigikocin, Erman; Mert, Behic; Alpas, Hami

    2011-09-01

    Both static and dynamic high pressure applications provide interesting modifications in food structures which lead to new product formulations. In this study, the effects of two different treatments, high hydrostatic pressure (HHP) and high dynamic pressure (HDP), on oil-in-water emulsions were identified and compared. Microfluidization was selected from among the HDP homogenization techniques. The performance of each process was analyzed in terms of rheological modifications and emulsion stability improvements compared with the coarse emulsions. The stability of the emulsions was determined comparatively by using an analytical photo-centrifuge device employing novel analysis technology. Whey protein isolate (WPI) in combination with a food polysaccharide (xanthan gum, guar gum or locust bean gum) were used as emulsifying and stabilizing ingredients. The effective disruption of oil droplets and the degradation of polysaccharides by the shear forces under high pressure in HDP microfluidization yielded finer emulsions with lower viscosities, leading to distinctive improvements in emulsion stability. On the other hand, improvements in stability obtained with HHP treatment were due to the thickening of the emulsions mainly induced by protein unfolding. The corresponding increases in viscosity were intensified in emulsion formulations containing higher oil content. Apart from these, HHP treatment was found to be relatively more contributive to the enhancements in viscoelastic properties.

  14. Evolutionary Diversification of the Vertebrate Transferrin Multi-gene Family

    PubMed Central

    Hughes, Austin L.; Friedman, Robert

    2014-01-01

    In a phylogenetic analysis of vertebrate transferrins (TFs), six major clades (subfamilies) were identified: (1) S, the mammalian serotransferrins; (2) ICA, the mammalian inhibitor of carbonic anhydrase (ICA) homologs; (3) L, the mammalian lactoferrins; (4) O, the ovotransferrins of birds and reptiles; (4) M, the melanotransferrins of bony fishes, amphibians, reptiles, birds, and mammals; and (5) M-like, a newly identified TF subfamily found in bony fishes, amphibians, reptiles, and birds. A phylogenetic tree based on the joint alignment of N-lobes and C-lobes supported the hypothesis that three separate events of internal duplication occurred in vertebrate TFs: (1) in the common ancestor of the M subfamily; (2) in the common ancestor of the M-like subfamily; and (3) in the common ancestor of other vertebrate TFs. The S, ICA, and L subfamilies were found only in placental mammals, and the phylogenetic analysis supported the hypothesis that these three subfamilies arose by gene duplication after the divergence of placental mammals from marsupials. The M-like subfamily was unusual in several respects, including the presence of a uniquely high proportion of clade-specific conserved residues, including distinctive but conserved residues in the sites homologous to those functioning in carbonate binding of human serotransferrin. The M-like family also showed a unusually high proportion of cationic residues in the positively charged region corresponding to human lactoferrampin, suggesting a distinctive role of this region in the M-like subfamily, perhaps in antimicrobial defense. PMID:25142446

  15. Radar range measurements in the atmosphere.

    SciTech Connect

    Doerry, Armin Walter

    2013-02-01

    The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  16. Lead exposure at uncovered outdoor firing ranges

    SciTech Connect

    Goldberg, R.L.; Hicks, A.M.; O'Leary, L.M.; London, S. )

    1991-06-01

    Excessive lead exposure in shooting instructors at indoor firing ranges and covered outdoor firing ranges has been documented. The City of Los Angeles assessed exposure of its full-time shooting instructors at uncovered outdoor ranges via air monitoring and blood lead-level measurements. Results of these tests revealed that significant lead exposure and absorption can occur at outdoor firing ranges. The use of copper-jacketed ammunition may decrease air lead levels and decrease lead absorption by range instructors.

  17. Highly Dynamic and Specific Phosphatidylinositol 4,5-Bisphosphate, Septin, and Cell Wall Integrity Pathway Responses Correlate with Caspofungin Activity against Candida albicans.

    PubMed

    Badrane, Hassan; Nguyen, M Hong; Clancy, Cornelius J

    2016-06-01

    Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] activates the yeast cell wall integrity pathway. Candida albicans exposure to caspofungin results in the rapid redistribution of PI(4,5)P2 and septins to plasma membrane foci and subsequent fungicidal effects. We studied C. albicans PI(4,5)P2 and septin dynamics and protein kinase C (PKC)-Mkc1 cell wall integrity pathway activation following exposure to caspofungin and other drugs. PI(4,5)P2 and septins were visualized by live imaging of C. albicans cells coexpressing green fluorescent protein (GFP)-pleckstrin homology (PH) domain and red fluorescent protein-Cdc10p, respectively. PI(4,5)P2 was also visualized in GFP-PH domain-expressing C. albicans mkc1 mutants. Mkc1p phosphorylation was measured as a marker of PKC-Mkc1 pathway activation. Fungicidal activity was assessed using 20-h time-kill assays. Caspofungin immediately induced PI(4,5)P2 and Cdc10p colocalization to aberrant foci, a process that was highly dynamic over 3 h. PI(4,5)P2 levels increased in a dose-response manner at caspofungin concentrations of ≤4× MIC and progressively decreased at concentrations of ≥8× MIC. Caspofungin exposure resulted in broad-based mother-daughter bud necks and arrested septum-like structures, in which PI(4,5)P2 and Cdc10 colocalized. PKC-Mkc1 pathway activation was maximal within 10 min, peaked in response to caspofungin at 4× MIC, and declined at higher concentrations. The caspofungin-induced PI(4,5)P2 redistribution remained apparent in mkc1 mutants. Caspofungin exerted dose-dependent killing and paradoxical effects at ≤4× and ≥8× MIC, respectively. Fluconazole, amphotericin B, calcofluor white, and H2O2 did not impact the PI(4,5)P2 or Cdc10p distribution like caspofungin did. Caspofungin exerts rapid PI(4,5)P2-septin and PKC-Mkc1 responses that correlate with the extent of C. albicans killing, and the responses are not induced by other antifungal agents. PI(4,5)P2-septin regulation is crucial in early

  18. Innovative approach to retrieve land surface emissivity and land surface temperature in areas of highly dynamic emissivity changes by using thermal infrared data

    NASA Astrophysics Data System (ADS)

    Heinemann, S.

    2015-12-01

    The land surface temperature (LST) is an extremely significant parameter in order to understand the processes of energetic interactions between Earth's surface and atmosphere. This knowledge is significant for various environmental research questions, particularly with regard to the recent climate change. This study shows an innovative approach to retrieve land surface emissivity (LSE) and LST by using thermal infrared (TIR) data from satellite sensors, such as SEVIRI and AATSR. So far there are no methods to derive LSE/LST particularly in areas of highly dynamic emissivity changes. Therefore especially for regions with large surface temperature amplitude in the diurnal cycle such as bare and uneven soil surfaces but also for regions with seasonal changes in vegetation cover including various surface areas such as grassland, mixed forests or agricultural land different methods were investigated to identify the most appropriate one. The LSE is retrieved by using the day/night Temperature-Independent Spectral Indices (TISI) method, and the Generalised Split-Window (GSW) method is used to retrieve the LST. Nevertheless different GSW algorithms show that equal LSEs lead to large LST differences. Additionally LSE is also measured using a NDVI-based threshold method (NDVITHM) to distinguish between soil, dense vegetation cover and pixel composed of soil and vegetation. The data used for this analysis were derived from MODIS TIR. The analysis is implemented with IDL and an intercomparison is performed to determine the most effective methods. To compensate temperature differences between derived and ground truth data appropriate correction terms by comparing derived LSE/LST data with ground-based measurements are developed. One way to calibrate LST retrievals is by comparing the canopy leaf temperature of conifers derived from TIR data with the surrounding air temperature (e.g. from synoptic stations). Prospectively, the derived LSE/LST data become validated with near

  19. Innovative approach to retrieve land surface emissivity and land surface temperature in areas of highly dynamic emissivity changes by using thermal infrared data

    NASA Astrophysics Data System (ADS)

    Heinemann, Sascha; Muro, Javier; Burkart, Andreas; Schultz, Johannes; Thonfeld, Frank; Menz, Gunter

    2016-04-01

    The land surface temperature (LST) is an extremely significant parameter in order to understand the processes of energetic interactions between the Earth's surface and the atmosphere. This knowledge is significant for various environmental research questions, particularly with regard to climate change. The current challenge is to reduce the higher deviations during daytime especially for bare areas with a maximum of 5.7 Kelvin. These temperature differences are time and vegetation cover dependent. This study shows an innovative approach to retrieve land surface emissivity (LSE) and LST by using thermal infrared (TIR) data from satellite sensors, such as SEVIRI and AATSR. So far there are no methods to derive LSE/LST particularly in areas of highly dynamic emissivity changes. Therefore especially for regions with large surface temperature amplitude in the diurnal cycle such as bare and uneven soil surfaces but also for regions with seasonal changes in vegetation cover including various surface areas such as grassland, mixed forests or agricultural land different methods were investigated to identify the most appropriate one. The LSE is retrieved by using the day/night Temperature-Independent Spectral Indices (TISI) method, while the Generalised Split-Window (GSW) method is used to retrieve the LST. Nevertheless different GSW algorithms show that equal LSEs lead to large LST differences. For bare surfaces during daytime the difference is about 6 Kelvin. Additionally LSE is also measured using a NDVI-based threshold method (NDVITHM) to distinguish between soil, dense vegetation cover and pixel composed of soil and vegetation. The data used for this analysis were derived from MODIS TIR. The analysis is implemented with IDL and an intercomparison is performed to determine the most effective methods. To compensate temperature differences between derived and ground truth data appropriate correction terms, by comparing derived LSE/LST data with ground-based measurements

  20. NASA Range Safety Annual Report 2007

    NASA Technical Reports Server (NTRS)

    Dumont, Alan G.

    2007-01-01

    As always, Range Safety has been involved in a number of exciting and challenging activities and events. Throughout the year, we have strived to meet our goal of protecting the public, the workforce, and property during range operations. During the past year, Range Safety was involved in the development, implementation, and support of range safety policy. Range Safety training curriculum development was completed this year and several courses were presented. Tailoring exercises concerning the Constellation Program were undertaken with representatives from the Constellation Program, the 45th Space Wing, and the Launch Constellation Range Safety Panel. Range Safety actively supported the Range Commanders Council and it subgroups and remained involved in updating policy related to flight safety systems and flight safety analysis. In addition, Range Safety supported the Space Shuttle Range Safety Panel and addressed policy concerning unmanned aircraft systems. Launch operations at Kennedy Space Center, the Eastern and Western ranges, Dryden Flight Research Center, and Wallops Flight Facility were addressed. Range Safety was also involved in the evaluation of a number of research and development efforts, including the space-based range (formerly STARS), the autonomous flight safety system, the enhanced flight termination system, and the joint advanced range safety system. Flight safety system challenges were evaluated. Range Safety's role in the Space Florida Customer Assistance Service Program for the Eastern Range was covered along with our support for the Space Florida Educational Balloon Release Program. We hope you have found the web-based format both accessible and easy to use. Anyone having questions or wishing to have an article included in the 2008 Range Safety Annual Report should contact Alan Dumont, the NASA Range Safety Program Manager located at the Kennedy Space Center, or Michael Dook at NASA Headquarters.

  1. Microprocessor realizations of range rate filters

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The performance of five digital range rate filters is evaluated. A range rate filter receives an input of range data from a radar unit and produces an output of smoothed range data and its estimated derivative range rate. The filters are compared through simulation on an IBM 370. Two of the filter designs are implemented on a 6800 microprocessor-based system. Comparisons are made on the bases of noise variance reduction ratios and convergence times of the filters in response to simulated range signals.

  2. CO2 laser ranging systems study

    NASA Technical Reports Server (NTRS)

    Filippi, C. A.

    1975-01-01

    The conceptual design and error performance of a CO2 laser ranging system are analyzed. Ranging signal and subsystem processing alternatives are identified, and their comprehensive evaluation yields preferred candidate solutions which are analyzed to derive range and range rate error contributions. The performance results are presented in the form of extensive tables and figures which identify the ranging accuracy compromises as a function of the key system design parameters and subsystem performance indexes. The ranging errors obtained are noted to be within the high accuracy requirements of existing NASA/GSFC missions with a proper system design.

  3. Application of microscopic image dynamic range enhancement in sputum smear tuberculosis intelligent examination

    NASA Astrophysics Data System (ADS)

    Zhong, Ping; Luo, Nian; Song, Chen-jie

    2009-07-01

    The bacteriological microscopic examination of sputum smear for tuberculosis is the most important means of diagnosis and experiments for tuberculosis. Through micro-imaging systems, machine vision systems, digital image processing and computer pattern recognition technology, dynamic intelligent recognition and counting of TB-DNA could be realized. However, the dynamic range of CCD image sensor is limited. The information of TB-DNA could not be fully recorded on microscopic image. In this paper, an effective method to extend the image dynamic range through merging multiple exposure images is proposed. The microscopic images of the same scene with different exposure are taken by rotating the disk-shaped optical grads attenuator that installed under the objective lens of microscopic system to control the illumination. These different exposure images are processed firstly to get irradiance response function of the imaging system, and then the high dynamic range microscopic image (HDRMI) could be obtained. Through the mapping algorithm the dynamic range of HDRMI is compressed in order to been displayed on the general display devices, which not only highlight the feature information of bacillus but also maintain the overall contrast of original microscopic image. The method proposed can effectively express the image information of the bright areas and dark areas in the scenes and enhance the image details and color characteristics. The quality of micro-imaging systems is improved. It is proved that the method proposed in the paper can enhance the resolution and stability of the TB image recognition through the experiment.

  4. Measurements of achromatic and chromatic contrast sensitivity functions for an extended range of adaptation luminance

    NASA Astrophysics Data System (ADS)

    Kim, Kil Joong; Mantiuk, Rafal; Lee, Kyoung Ho

    2013-03-01

    Inspired by the ModelFest and ColorFest data sets, a contrast sensitivity function was measured for a wide range of adapting luminance levels. The measurements were motivated by the need to collect visual performance data for natural viewing of static images at a broad range of luminance levels, such as can be found in the case of high dynamic range displays. The detection of sine-gratings with Gaussian envelope was measured for achromatic color axis (black to white), two chromatic axes (green to red and yellow-green to violet) and two mixed chromatic and achromatic axes (dark-green to light-pink, and dark yellow to light-blue). The background luminance varied from 0.02 to 200 cd/m2. The spatial frequency of the gratings varied from 0.125 to 16 cycles per degree. More than four observers participated in the experiments and they individually determined the detection threshold for each stimulus using at least 20 trials of the QUEST method. As compared to the popular CSF models, we observed higher sensitivity drop for higher frequencies and significant differences in sensitivities in the luminance range between 0.02 and 2 cd/m2. Our measurements for chromatic CSF show a significant drop in sensitivity with luminance, but little change in the shape of the CSF. The drop of sensitivity at high frequencies is significantly weaker than reported in other studies and assumed in most chromatic CSF models.

  5. 2006 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    TenHaken, Ron; Daniels, B.; Becker, M.; Barnes, Zack; Donovan, Shawn; Manley, Brenda

    2007-01-01

    Throughout 2006, Range Safety was involved in a number of exciting and challenging activities and events, from developing, implementing, and supporting Range Safety policies and procedures-such as the Space Shuttle Launch and Landing Plans, the Range Safety Variance Process, and the Expendable Launch Vehicle Safety Program procedures-to evaluating new technologies. Range Safety training development is almost complete with the last course scheduled to go on line in mid-2007. Range Safety representatives took part in a number of panels and councils, including the newly formed Launch Constellation Range Safety Panel, the Range Commanders Council and its subgroups, the Space Shuttle Range Safety Panel, and the unmanned aircraft systems working group. Space based range safety demonstration and certification (formerly STARS) and the autonomous flight safety system were successfully tested. The enhanced flight termination system will be tested in early 2007 and the joint advanced range safety system mission analysis software tool is nearing operational status. New technologies being evaluated included a processor for real-time compensation in long range imaging, automated range surveillance using radio interferometry, and a space based range command and telemetry processor. Next year holds great promise as we continue ensuring safety while pursuing our quest beyond the Moon to Mars.

  6. 2012 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    Dumont, Alan G.

    2012-01-01

    This report provides a NASA Range Safety (NRS) overview for current and potential range users. This report contains articles which cover a variety of subject areas, summaries of various NASA Range Safety Program (RSP) activities performed during the past year, links to past reports, and information on several projects that may have a profound impact on the way business will be conducted in the future. Specific topics discussed in the 2012 NASA Range Safety Annual Report include a program overview and 2012 highlights; Range Safety Training; Independent Assessments; Support to Program Operations at all ranges conducting NASA launch/flight operations; a continuing overview of emerging range safety-related technologies; and status reports from all of the NASA Centers that have Range Safety responsibilities.

  7. 2009 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    2010-01-01

    This year, NASA Range Safety transitioned to a condensed annual report to allow for Secretariat support to the Range Safety Group, Risk Committee. Although much shorter than in previous years, this report contains full-length articles concerning various subject areas, as well as links to past reports. Additionally, summaries from various NASA Range Safety Program activities that took place throughout the year are presented, as well as information on several projects that may have a profound impact on the way business will be done in the future. The sections include a program overview and 2009 highlights; Range Safety Training; Range Safety Policy; Independent Assessments Support to Program Operations at all ranges conducting NASA launch operations; a continuing overview of emerging range safety-related technologies; and status reports from all of the NASA Centers that have Range Safety responsibilities.

  8. 33 CFR 62.41 - Ranges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids...

  9. 33 CFR 62.41 - Ranges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids...

  10. 33 CFR 62.41 - Ranges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids...

  11. 33 CFR 62.41 - Ranges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids...

  12. 33 CFR 62.41 - Ranges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids...

  13. 36 CFR 222.9 - Range improvements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Range improvements. 222.9 Section 222.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE RANGE MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.9 Range improvements. (a) The Chief, Forest Service, is authorized to install...

  14. The X-33 Extended Flight Test Range

    NASA Technical Reports Server (NTRS)

    Mackall, Dale A.; Sakahara, Robert; Kremer, Steven E.

    1998-01-01

    Development of an extended test range, with range instrumentation providing continuous vehicle communications, is required to flight-test the X-33, a scaled version of a reusable launch vehicle. The extended test range provides vehicle communications coverage from California to landing at Montana or Utah. This paper provides an overview of the approaches used to meet X-33 program requirements, including using multiple ground stations, and methods to reduce problems caused by reentry plasma radio frequency blackout. The advances used to develop the extended test range show other hypersonic and access-to-space programs can benefit from the development of the extended test range.

  15. Accuracy analysis of optical ranging in atmosphere

    NASA Astrophysics Data System (ADS)

    Yuan, Hong-wu; Huang, Yin-bo; Mei, Hai-ping; Rao, Rui-zhong

    2009-07-01

    Optical ranging is one of the most precise techniques for distance measurement. The effects of the density variation of atmosphere, aerosols and clouds on optical ranging precision are generally considered, a new method is proposed for calculating the ranging precision in the presence of aerosol particles and clouds. The size distribution spectrum models for aerosols and clouds in the Optical Properties of Aerosols and Clouds Package (OPAC) are adopted. Results show that aerosols and clouds could introduce errors of several centimeters to several ten meters to the ranging. The relationship between the ranging precision and the relative humidity, the zenith angle of ranging direction and the optical wavelength is also analyzed. The ranging error doesn't have an obvious relationship with the wavelength, but depends on the zenith angle, especially for the angle larger than 70 degree. The ranging error depends on the relative humidity as well. The ranging error induced by aerosols increases gradually with the increase of the relative humidity when the relative humidity is less than 80%, but it increases rapidly when the relative humidity is larger than 80%. Our results could provide a theoretical basis and reference for the application of optical ranging.

  16. Tonopah Test Range capabilities: technical manual

    SciTech Connect

    Manhart, R.L.

    1982-11-01

    This manual describes Tonopah Test Range (TTR), defines its testing capabilities, and outlines the steps necessary to schedule tests on the Range. Operated by Sandia National Laboratories, TTR is a major test facility for DOE-funded weapon programs. The Range presents an integrated system for ballistic test vehicle tracking and data acquisition. Multiple radars, optical trackers, telemetry stations, a central computer complex, and combined landline/RF communications systems assure full Range coverage for any type of test. Range operations are conducted by a department within Sandia's Field Engineering Directorate. While the overall Range functions as a complete system, it is operationally divided into the Test Measurements, Instrumentation Development, and Range Operations divisions. The primary function of TTR is to support DOE weapons test activities. Management, however, encourages other Government agencies and their contractors to schedule tests on the Range which can make effective use of its capabilities. Information concerning Range use by organizations outside of DOE is presented. Range instrumentation and support facilities are described in detail. This equipment represents the current state-of-the-art and reflects a continuing commitment by TTR management to field the most effective tracking and data acquisition system available.

  17. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements.

    PubMed

    George Abraham, Bobin; Sarkisyan, Karen S; Mishin, Alexander S; Santala, Ville; Tkachenko, Nikolai V; Karp, Matti

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM). PMID:26237400

  18. Range filtering for sequential GPS receivers

    NASA Technical Reports Server (NTRS)

    Paielli, Russell

    1987-01-01

    The filtering of the satellite range and range-rate measurements from single channel sequential Global Positioning System receivers is usually done with an extended Kalman filter which has state variables defined in terms of an orthogonal navigation reference frame. An attractive suboptimal alternative is range-domain filtering, in which the individual satellite measurements are filtered separately before they are combined for the navigation solution. The main advantages of range-domain filtering are decreased processing and storage requirements and simplified tuning. Several range filter mechanization alternatives are presented, along with an innovative approach for combining the filtered range-domain quantities to determine the navigation state estimate. In addition, a method is outlined for incorporating measurements from auxiliary sensors such as altimeters into the navigation state estimation scheme similarly to the satellite measurements. A method is also described for incorporating inertial measurements into the navigation state estimator as a process driver.

  19. Reindeer ranges inventory in western Alaska

    NASA Technical Reports Server (NTRS)

    George, T. H.

    1981-01-01

    The use of LANDSAT data as a tool for reindeer range inventory on the tundra of northwestern Alaska is addressed. The specific goal is to map the range resource and estimate plant productivity of the Seward Peninsula. Information derived from these surveys is needed to develop range management plans for reindeer herding and to evaluate potential conflicting use between reindeer and caribou. The development of computer image classification techniques is discussed.

  20. An algorithm for segmenting range imagery

    SciTech Connect

    Roberts, R.S.

    1997-03-01

    This report describes the technical accomplishments of the FY96 Cross Cutting and Advanced Technology (CC&AT) project at Los Alamos National Laboratory. The project focused on developing algorithms for segmenting range images. The image segmentation algorithm developed during the project is described here. In addition to segmenting range images, the algorithm can fuse multiple range images thereby providing true 3D scene models. The algorithm has been incorporated into the Rapid World Modelling System at Sandia National Laboratory.

  1. Long-range neural synchrony in behavior.

    PubMed

    Harris, Alexander Z; Gordon, Joshua A

    2015-07-01

    Long-range synchrony between distant brain regions accompanies multiple forms of behavior. This review compares and contrasts the methods by which long-range synchrony is evaluated in both humans and model animals. Three examples of behaviorally relevant long-range synchrony are discussed in detail: gamma-frequency synchrony during visual perception, hippocampal-prefrontal synchrony during working memory, and prefrontal-amygdala synchrony during anxiety. Implications for circuit mechanism, translation, and clinical relevance are discussed. PMID:25897876

  2. Clutter rejection limitations from ambiguous range clutter

    NASA Astrophysics Data System (ADS)

    Reilly, J. Patrick

    Limitations on achievable clutter rejection due to ambiguous range clutter are described. The profile of clutter power versus range is shown to limit achievable clutter rejection. Ambiguous range effects are discussed in the context of sea clutter, using a model that includes propagation conditions, and rain clutter. Limitations in moving target indication systems are illustrated for sea clutter, where propagation is subject to evaporation ducts. Benefits of fill pulses are illustrated for rain and sea clutter.

  3. Long-range neural synchrony in behavior

    PubMed Central

    Harris, Alexander Z.; Gordon, Joshua A.

    2015-01-01

    Long-range synchrony between distant brain regions accompanies multiple forms of behavior. This review compares and contrasts the methods by which long-range synchrony is evaluated in both humans and model animals. Three examples of behaviorally-relevant long-range synchrony are discussed in detail: gamma-frequency synchrony during visual perception; hippocampal-prefrontal synchrony during working memory; and prefrontal-amygdala synchrony during anxiety. Implications for circuit mechanism, translation, and clinical relevance are discussed. PMID:25897876

  4. The Dissipation Range in Rotating Turbulence

    NASA Technical Reports Server (NTRS)

    Rubinstein, Robert; Zhou, Ye

    1999-01-01

    The dissipation range energy balance of the direct interaction approximation is applied to rotating turbulence when rotation effects persist well into the dissipation range. Assuming that RoRe (exp 1/2) is much less than 1 and that three-wave interactions are dominant, the dissipation range is found to be concentrated in the wavevector plane perpendicular to the rotation axis. This conclusion is consistent with previous analyses of inertial range energy transfer in rotating turbulence, which predict the accumulation of energy in those scales.

  5. 2010 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    Dumont, Alan G.

    2010-01-01

    this report provides a NASA Range Safety overview for current and potential range users. This report contains articles which cover a variety of subject areas, summaries of various NASA Range Safety Program activities conducted during the past year, links to past reports, and information on several projects that may have a profound impact on the way business will be done in the future. Specific topics discussed in the 2010 NASA Range Safety Annual Report include a program overview and 2010 highlights; Range Safety Training; Range Safety Policy revision; Independent Assessments; Support to Program Operations at all ranges conducting NASA launch/flight operations; a continuing overview of emerging range safety-related technologies; and status reports from all of the NASA Centers that have Range Safety responsibilities. Every effort has been made to include the most current information available. We recommend this report be used only for guidance and that the validity and accuracy of all articles be verified for updates. Once again, the web-based format was used to present the annual report.

  6. Compact range test applications, phase 2

    NASA Astrophysics Data System (ADS)

    Davis, Francis L.

    1992-01-01

    Georgia Tech Research Institute (GTRI) has designed and fabricated a large outdoor Compact Antenna Range for the U.S. Army Electronic Proving Ground (USAEPG). This range enables USAEPG to test antenna systems of large ground vehicles or aircraft that weigh up to 70 tons and are up to 50 feet in size over a frequency range of 6 to 40 GHz. Ongoing investigation and study are being conducted to determine the compatibility and adaptability of this antenna pattern measurement range to measure other system parameters such as target return signals and system responses to specialized electromagnetic environments.

  7. 2011 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    Dumont, Alan G.

    2012-01-01

    Welcome to the 2011 edition of the NASA Range Safety Annual Report. Funded by NASA Headquarters, this report provides a NASA Range Safety overview for current and potential range users. As is typical with odd year editions, this is an abbreviated Range Safety Annual Report providing updates and links to full articles from the previous year's report. It also provides more complete articles covering new subject areas, summaries of various NASA Range Safety Program activities conducted during the past year, and information on several projects that may have a profound impact on the way business will be done in the future. Specific topics discussed and updated in the 2011 NASA Range Safety Annual Report include a program overview and 2011 highlights; Range Safety Training; Range Safety Policy revision; Independent Assessments; Support to Program Operations at all ranges conducting NASA launch/flight operations; a continuing overview of emerging range safety-related technologies; and status reports from all of the NASA Centers that have Range Safety responsibilities. Every effort has been made to include the most current information available. We recommend this report be used only for guidance and that the validity and accuracy of all articles be verified for updates. Once again the web-based format was used to present the annual report. We continually receive positive feedback on the web-based edition and hope you enjoy this year's product as well. As is the case each year, contributors to this report are too numerous to mention, but we thank individuals from the NASA Centers, the Department of Defense, and civilian organizations for their contributions. In conclusion, it has been a busy and productive year. I'd like to extend a personal Thank You to everyone who contributed to make this year a successful one, and I look forward to working with all of you in the upcoming year.

  8. 1995-1998 Long Range Plan.

    ERIC Educational Resources Information Center

    Pennsylvania Coll. of Technology, Williamsport.

    At Pennsylvania College of Technology (PCT), in Williamsport, long range planning is used to define institutional philosophy and mission and determine strategies to make the best use of available resources and implement actions to fulfill institutional mission. This document presents PCT's long-range plan for 1995-98 in three parts. Following an…

  9. Long Range Plan: 1992-1995.

    ERIC Educational Resources Information Center

    Pennsylvania Coll. of Technology, Williamsport.

    Intended to enhance strategic planning and enable staff to work as a team toward a shared vision and common goals, this report presents the 1992-95 long-range plan of the Pennsylvania College of Technology (PCT). Part I defines long-range planning; describes the structure and use of the plan at PCT; presents PCT's philosophy, mission, and vision…

  10. Long Range Plan, 1991-1994.

    ERIC Educational Resources Information Center

    Pennsylvania Coll. of Technology, Williamsport.

    This long-range plan for the Pennsylvania College of Technology (PCT) is divided into three main sections. Part I provides an overview of planning at PCT, including a definition of long-range planning, the college philosophy, mission, and vision statements, major institutional initiatives for 1991-92, and accreditation agency recommendations…

  11. Long Range Plan, 1997-2000.

    ERIC Educational Resources Information Center

    Pennsylvania Coll. of Technology, Williamsport. Office of Strategic Planning and Research.

    At Pennsylvania College of Technology (PCT), long range planning is used to define institutional philosophy and mission and determine strategies to make the best use of available resources and implement actions to fulfill institutional mission. This document presents PCT's long-range plan for 1997-2000 in three parts. The first part describes long…

  12. College and University Long-Range Planning.

    ERIC Educational Resources Information Center

    Haas, Raymond M.

    The system for long-range planning at West Virginia University is described, with emphasis on how it relates to short-range planning and how it is carried out operationally. Planning tools used include (1) an inventory of the past and present of the institution, (2) a statement of the division of labor within the institution and the objectives of…

  13. 36 CFR 222.9 - Range improvements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.9 Range improvements. (a) The Chief... needed to manage the range resource on National Forest System lands and other lands controlled by the... performed by a cooperator or permittee on National Forest System lands shall not confer the exclusive...

  14. 36 CFR 222.9 - Range improvements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.9 Range improvements. (a) The Chief... needed to manage the range resource on National Forest System lands and other lands controlled by the... performed by a cooperator or permittee on National Forest System lands shall not confer the exclusive...

  15. 36 CFR 222.9 - Range improvements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.9 Range improvements. (a) The Chief... needed to manage the range resource on National Forest System lands and other lands controlled by the... performed by a cooperator or permittee on National Forest System lands shall not confer the exclusive...

  16. Personality Correlates of Social Role Range.

    ERIC Educational Resources Information Center

    McReynolds, Paul; And Others

    The concept of social role range (SRR) deals with the magnitude of an individual's repertoire of different interpersonal behavior patterns and exhibits the properties of a personality trait. Over a broad range of interpersonal settings, individuals tend to be consistent in the magnitude of their SRR's. A role play technique was devised for…

  17. Undergraduate range management exam: 1999-2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Undergraduate Range Management Exam (URME) has been administered to undergraduate students at the Annual Meeting of the Society for Range Management since 1983, with students demonstrating their higher order learning skills and synthesis knowledge of the art and science of rangeland management. ...

  18. 5 CFR 534.502 - Pay range.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Pay range. 534.502 Section 534.502 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Pay for Senior-Level and Scientific and Professional Positions § 534.502 Pay range. A pay rate fixed under...

  19. 5 CFR 534.502 - Pay range.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Pay range. 534.502 Section 534.502 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Pay for Senior-Level and Scientific and Professional Positions § 534.502 Pay range. A pay rate fixed under...

  20. 5 CFR 534.502 - Pay range.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Pay range. 534.502 Section 534.502 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Pay for Senior-Level and Scientific and Professional Positions § 534.502 Pay range. A pay rate fixed under this subpart shall be— (a) Not less...

  1. 5 CFR 534.502 - Pay range.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Pay range. 534.502 Section 534.502 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Pay for Senior-Level and Scientific and Professional Positions § 534.502 Pay range. A pay rate fixed under...

  2. Experiments: Test range facilities, part 2

    NASA Astrophysics Data System (ADS)

    Dudley, D. G.

    1987-06-01

    A description is given of the electromagnetic transient range facility at the Lawrence Livermore Laboratory. The range design and the instrumentation for both time domain and broadband frequency domain measurements are discussed. Two examples of experiments are given: scattering from a conducting plate and transmission through an aperture in a screen.

  3. Nevada Livestock Grazing and Range Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The range livestock industry had a very slow start in Nevada because it was commonly accepted that the environment would not support livestock production. Freighters discovered that oxen could winter on the dry herbage of desert bunchgrasses and come off the range in excellent condition in the spri...

  4. Range contraction in large pelagic predators

    PubMed Central

    Worm, Boris; Tittensor, Derek P.

    2011-01-01

    Large reductions in the abundance of exploited land predators have led to significant range contractions for those species. This pattern can be formalized as the range–abundance relationship, a general macroecological pattern that has important implications for the conservation of threatened species. Here we ask whether similar responses may have occurred in highly mobile pelagic predators, specifically 13 species of tuna and billfish. We analyzed two multidecadal global data sets on the spatial distribution of catches and fishing effort targeting these species and compared these with available abundance time series from stock assessments. We calculated the effort needed to reliably detect the presence of a species and then computed observed range sizes in each decade from 1960 to 2000. Results suggest significant range contractions in 9 of the 13 species considered here (between 2% and 46% loss of observed range) and significant range expansions in two species (11–29% increase). Species that have undergone the largest declines in abundance and are of particular conservation concern tended to show the largest range contractions. These include all three species of bluefin tuna and several marlin species. In contrast, skipjack tuna, which may have increased its abundance in the Pacific, has also expanded its range size. These results mirror patterns described for many land predators, despite considerable differences in habitat, mobility, and dispersal, and imply ecological extirpation of heavily exploited species across parts of their range. PMID:21693644

  5. The Geoscience Laser Altimetry/Ranging System

    NASA Technical Reports Server (NTRS)

    Cohen, Steven C.; Degnan, John J., III; Bufton, Jack L.; Garvin, James B.; Abshire, James B.

    1987-01-01

    The Geoscience Laser Altimetry/Ranging System (GLARS), a combined laser ranging and altimetry system capable of subcentimeter position determinations of retroflector targets and subdecimeter profiling of topography, is described. The system uses advanced but currently available state-of-the-art components. Laboratory, field, and numerical experiments have indicated the suitability of GLARS as an instrument for Eos and other space platforms.

  6. Exploration of polygonal environments using range data.

    PubMed

    Ekman, A; Torne, A; Stromberg, D

    1997-01-01

    Several robotic problems involve the systematic traversal of the environment, commonly referred to as exploration. We present a strategy for the exploration of unknown finite polygonal environments, using a point robot with 1) no positional uncertainty and 2) an ideal range sensor that measures range in N uniformly distributed directions. The range data vector, obtained from the range sensor, corresponds to a sampled version of a visibility polygon. Visibility polygon edges that do not correspond to environmental edges are called jump edges and the exploration strategy is based on the fact that jump edges indicate directions of possibly unexplored environmental regions. We describe conditions under which it is possible to identify jump edges in the range data. We also show how the exploration strategy can be used in a solution to the terrain acquisition problem and describe conditions under which a solution is guaranteed within a finite number of measurements. PMID:18255863

  7. Range gated imaging experiments using gated intensifiers

    SciTech Connect

    McDonald, T.E. Jr.; Yates, G.J.; Cverna, F.H.; Gallegos, R.A.; Jaramillo, S.A.; Numkena, D.M.; Payton, J.; Pena-Abeyta, C.R.

    1999-03-01

    A variety of range gated imaging experiments using high-speed gated/shuttered proximity focused microchannel plate image intensifiers (MCPII) are reported. Range gated imaging experiments were conducted in water for detection of submerged mines in controlled turbidity tank test and in sea water for the Naval Coastal Sea Command/US Marine Corps. Field experiments have been conducted consisting of kilometer range imaging of resolution targets and military vehicles in atmosphere at Eglin Air Force Base for the US Air Force, and similar imaging experiments, but in smoke environment, at Redstone Arsenal for the US Army Aviation and Missile Command (AMCOM). Wavelength of the illuminating laser was 532 nm with pulse width ranging from 6 to 12 ns and comparable gate widths. These tests have shown depth resolution in the tens of centimeters range from time phasing reflected LADAR images with MCPII shutter opening.

  8. Eighth International Workshop on Laser Ranging Instrumentation

    NASA Technical Reports Server (NTRS)

    Degnan, John J. (Compiler)

    1993-01-01

    The Eighth International Workshop for Laser Ranging Instrumentation was held in Annapolis, Maryland in May 1992, and was sponsored by the NASA Goddard Space Flight Center in Greenbelt, Maryland. The workshop is held once every 2 to 3 years under differing institutional sponsorship and provides a forum for participants to exchange information on the latest developments in satellite and lunar laser ranging hardware, software, science applications, and data analysis techniques. The satellite laser ranging (SLR) technique provides sub-centimeter precision range measurements to artificial satellites and the Moon. The data has application to a wide range of Earth and lunar science issues including precise orbit determination, terrestrial reference frames, geodesy, geodynamics, oceanography, time transfer, lunar dynamics, gravity and relativity.

  9. Tests of gravity Using Lunar Laser Ranging

    NASA Technical Reports Server (NTRS)

    Merkowitz, Stephen M.

    2010-01-01

    Lunar laser ranging (LLR) has been a workhorse for testing general relativity over the pat four decades. The three retrorefiector arrays put on the Moon by the Apollo astronauts and the French built array on the second Soviet Lunokhod rover continue to be useful targets, and have provided the most stringent tests of the Strong Equivalence Principle and the time variation of Newton's gravitational constant. The relatively new ranging system at the Apache Point :3.5 meter telescope now routinely makes millimeter level range measurements. Incredibly. it has taken 40 years for ground station technology to advance to the point where characteristics of the lunar retrorefiectors are limiting the precision of the range measurements. In this article. we review the gravitational science and technology of lunar laser ranging and discuss prospects for the future.

  10. Illuminating geographical patterns in species' range shifts.

    PubMed

    Grenouillet, Gaël; Comte, Lise

    2014-10-01

    Species' range shifts in response to ongoing climate change have been widely documented, but although complex spatial patterns in species' responses are expected to be common, comprehensive comparisons of species' ranges over time have undergone little investigation. Here, we outline a modeling framework based on historical and current species distribution records for disentangling different drivers (i.e. climatic vs. nonclimatic) and assessing distinct facets (i.e. colonization, extirpation, persistence, and lags) of species' range shifts. We used extensive monitoring data for stream fish assemblages throughout France to assess range shifts for 32 fish species between an initial period (1980-1992) and a contemporary one (2003-2009). Our results provide strong evidence that the responses of individual species varied considerably and exhibited complex mosaics of spatial rearrangements. By dissociating range shifts in climatically suitable and unsuitable habitats, we demonstrated that patterns in climate-driven colonization and extirpation were less marked than those attributed to nonclimatic drivers, although this situation could rapidly shift in the near future. We also found evidence that range shifts could be related to some species' traits and that the traits involved varied depending on the facet of range shift considered. The persistence of populations in climatically unsuitable areas was greater for short-lived species, whereas the extent of the lag behind climate change was greater for long-lived, restricted-range, and low-elevation species. We further demonstrated that nonclimatic extirpations were primarily related to the size of the species' range, whereas climate-driven extirpations were better explained by thermal tolerance. Thus, the proposed framework demonstrated its potential for markedly improving our understanding of the key processes involved in range shifting and also offers a template for informing management decisions. Conservation strategies

  11. 2013 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    Dumont, Alan G.

    2013-01-01

    Welcome to the 2013 edition of the NASA Range Safety Annual Report. Funded by NASA Headquarters, this report provides an Agency overview for current and potential range users. This report contains articles which cover a variety of subject areas, summaries of various activities performed during the past year, links to past reports, and information on several projects that may have a profound impact on the way business will be conducted in the future. Specific topics discussed in the 2013 NASA Range Safety Annual Report include a program overview and 2013 highlights, Range Safety Training, Independent Assessments, support to Program Operations at all ranges conducting NASA launch/flight operations, a continuing overview of emerging range safety-related technologies, and status reports from all of the NASA Centers that have Range Safety responsibilities. Every effort has been made to include the most current information available. We recommend this report be used only for guidance and that the validity and accuracy of all articles be verified for updates. As is the case each year, we had a wide variety of contributors to this report from across our NASA Centers and the national range safety community at large, and I wish to thank them all. On a sad note, we lost one of our close colleagues, Dr. Jim Simpson, due to his sudden passing in December. His work advancing the envelope of autonomous flight safety systems software/hardware development leaves a lasting impression on our community. Such systems are being flight tested today and may one day be considered routine in the range safety business. The NASA family has lost a pioneer in our field, and he will surely be missed. In conclusion, it has been a very busy and productive year, and I look forward to working with all of you in NASA Centers/Programs/Projects and with the national Range Safety community in making Flight/Space activities as safe as they can be in the upcoming year.

  12. Trilateration range and range rate system. Volume 1: CDA system manual

    NASA Technical Reports Server (NTRS)

    1976-01-01

    This document is one of a series of manuals designed to provide the information required to operate and maintain the Command and Data Acquisition (CDA) equipment of the Trilateration Range and Range Rate (TRRR) System. Information pertaining to the equipment in the Trilateration Range and Range Rate System which is designed to interface with existing NASA equipment located at Wallops Island, Virginia is presented.

  13. Range and habitats of the desert tortoise

    USGS Publications Warehouse

    Germano, D.J.; Bury, R.B.; Esque, T.C.; Fritts, T.H.

    1994-01-01

    We determined the current range of the desert tortoise (Gopherus agassizii) based on the available latest data from government agencies, the literature, and our experience. We developed the first detailed range map of this species and summarized information about habitat preferences. New records of occurrences were incorporated, and some peripheral localities of questionable authenticity were deleted. The distribution oCG. agassizii covers the broadest range of latitude, climatic regimes, habitats, and biotic regions of any North American tortoise. The northern portion ofits range is in the Mojave Desert of sDuth"eastern California, southern Nevada, southwestern Utah, and northwestern Arizona. The central portion of the range consists of several subdivisions of the Sonaran Desert in southeastern California, western and southern Arizona, and western Sonora, Mexico. The southern edge of its range is in the semitropical Sinaloan thornscrub and Sinaloan deciduous forest of eastern Sonora and northern Sinaloa, Mexico. This species has marked geogi-aphic differences but seems to construct burrows throughout its range.

  14. Passive ranging within a differential framework

    NASA Astrophysics Data System (ADS)

    Yang, Qingguo; Liu, Liren; Liu, De'an; Sun, Jianfeng; Zhu, Yongjian; Lu, Wei

    2006-08-01

    Finding the distance of object in a scene from vision information is an important problem in machine vision. A large number of techniques for passive ranging of unknown objects have been developed over the years (i.e. range from stereo, motion, focus and defocus). Nearly all such techniques may be framed in terms of a differential formalism. In the case of binocular stereo, two different images are taken from cameras at different discrete viewpoints, similarly, difference between consecutive images are often used to determine viewpoint derivatives for structure from motion and two or more different images taken from cameras with different aperture size are used to compute the derivative respect to aperture size for range from focus and defocus method. All this methods may be fallen into a discrete differentiation category. Farid proposed a consecutive differentiation method for range estimation which employs the intensity variation of the images along with the aperture changes to measure the range information. In this paper, we first consider the plenoptic function which is a powerful mathematical tool for understanding the primary vision problem. We then show an algorithm within a differential framework for range estimation based on the assumption of brightness constancy. Finally we show several implementations of passive ranging using this differential algorithm.

  15. Strainrange partitioning: A total strain range version

    NASA Technical Reports Server (NTRS)

    Halford, G. R.; Saltsman, J. F.

    1983-01-01

    Procedures are presented for expressing the Strainrange Partitioning (SRP) method for creep fatigue life prediction in terms of total strain range. Inelastic and elastic strain-range - life relations are summed to give total strain-range - life relations. The life components due to inelastic strains are dealt with using conventional SRP procedures while the life components due to elastic strains are expressed as families of time-dependent terms for each type of SRP cycle. Cyclic constitutive material behavior plays an important role in establishing the elastic strain-range - life relations as well as the partitioning of the inelastic strains. To apply the approach, however, it is not necessary to have to determine the magnitude of the inelastic strain range. The total strain SRP approach is evaluated and verified using two nickel base superalloys, AF2-1DA and Rene 95. Excellent agreement is demonstrated between observed and predicted cyclic lifetimes with 70 to 80 percent of the predicted lives falling within factors of two of the observed lives. The total strain-range SRP approach should be of considerable practical value to designers who are faced with creep-fatigue problems for which the inelastic strains cannot be calculated with sufficient accuracy to make reliable life predictions by the conventional inelastic strain range SRP approach.

  16. Laser System for Precise, Unambiguous Range Measurements

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, Oliver

    2005-01-01

    The Modulation Sideband Technology for Absolute Range (MSTAR) architecture is the basis of design of a proposed laser-based heterodyne interferometer that could measure a range (distance) as great as 100 km with a precision and resolution of the order of 1 nm. Simple optical interferometers can measure changes in range with nanometer resolution, but cannot measure range itself because interference is subject to the well-known integer-multiple-of-2 -radians phase ambiguity, which amounts to a range ambiguity of the order of 1 m at typical laser wavelengths. Existing rangefinders have a resolution of the order of 10 m and are therefore unable to resolve the ambiguity. The proposed MSTAR architecture bridges the gap, enabling nanometer resolution with an ambiguity range that can be extended to arbitrarily large distances. The MSTAR architecture combines the principle of the heterodyne interferometer with the principle of extending the ambiguity range of an interferometer by using light of two wavelengths. The use of two wavelengths for this purpose is well established in optical metrology, radar, and sonar. However, unlike in traditional two-color laser interferometry, light of two wavelengths would not be generated by two lasers. Instead, multiple wavelengths would be generated as sidebands of phase modulation of the light from a single frequency- stabilized laser. The phase modulation would be effected by applying sinusoidal signals of suitable frequencies (typically tens of gigahertz) to high-speed electro-optical phase modulators. Intensity modulation can also be used

  17. Demonstration of high sensitivity laser ranging system

    NASA Technical Reports Server (NTRS)

    Millar, Pamela S.; Christian, Kent D.; Field, Christopher T.

    1994-01-01

    We report on a high sensitivity semiconductor laser ranging system developed for the Gravity and Magnetic Earth Surveyor (GAMES) for measuring variations in the planet's gravity field. The GAMES laser ranging instrument (LRI) consists of a pair of co-orbiting satellites, one which contains the laser transmitter and receiver and one with a passive retro-reflector mounted in an drag-stabilized housing. The LRI will range up to 200 km in space to the retro-reflector satellite. As the spacecraft pair pass over the spatial variations in the gravity field, they experience along-track accelerations which change their relative velocity. These time displaced velocity changes are sensed by the LRI with a resolution of 20-50 microns/sec. In addition, the pair may at any given time be drifting together or apart at a rate of up to 1 m/sec, introducing a Doppler shift into the ranging signals. An AlGaAs laser transmitter intensity modulated at 2 GHz and 10 MHz is used as fine and medium ranging channels. Range is measured by comparing phase difference between the transmit and received signals at each frequency. A separate laser modulated with a digital code, not reported in this paper, will be used for coarse ranging to unambiguously determine the distance up to 200 km.

  18. Determination of range parameters of observation devices

    NASA Astrophysics Data System (ADS)

    Bareła, J.; Kastek, M.; Firmanty, K.; Trzaskawka, P.; Dulski, R.; Kucharz, J.

    2012-10-01

    Range parameters of observation devices can be determined on the basis of numerical simulations (NVTherm) or on the basis of measured characteristics. Those measurements can be conducted in both laboratory and field conditions. It is, however, difficult to carry on reliable field measurements of range parameters because they are strongly depended on atmospheric conditions. Thus the laboratory measurements are more favorable option. Analysis of literature and catalogue specifications reveal, that range parameters are given mainly on the basis of Johnson criteria or TTP model. The Johnson criteria has been used since the 50s and most of catalogue range specifications are determined according to it. There are also NATO standards, which describe the measurement procedures and methodology required to define the detection, recognition and identification ranges for standard NATO targets. For the determination of range parameters the following device characteristics must be known: minimal resolvable temperature for thermal imaging devices and minimal resolvable contrast for VIS devices. The TTP model offers a new approach to the determination of range characteristics of observation devices. It has been developed by U.S. Army's Night Vision and Electronic Sensors Directorate since the year 2000. It was created because the modified Johnson criteria did not yield reliable results in case of modern systems with digital image processing. In order to determine the range parameters using TTP model, the modulation transfer function MTF, presample MTF function, and 3D noise of a tested system must be known as well as its basic design data as optical magnification and display type. The paper describes the measurement stand, measurement methodology and the procedure for the determination of range parameters. The results for thermal and VIS cameras are also presented, and they are analyzed and compared with the results obtained from current methods, including the measurement

  19. Automatic laser tracking and ranging system.

    PubMed

    Cooke, C R

    1972-02-01

    An automatic laser tracking and ranging system has been developed for use with cooperative retroreflective targets. Target position is determined with high precision at ranges out to 19 km and sample rates up to one hundred measurements per second. The data are recorded on a magnetic tape in the form of azimuth, elevation, range, and standard time and are computer-compatible. The system is fully automatic with the exception of the initial acquisition sequence, which is performed manually. This eliminates the need for expensive and time-consuming photographic data reduction. Also, position is uniquely determined by a single instrument. To provide convenient operation at remote sites, the system is van-mounted and operates off a portable power generator. The transmitter is a flash-pumped Q-spoiled Nd:YAG laser developing 1 MW peak power in a 10-mrad beam at a rate of 100 pps. The beam, which is coaxial with the receiver, is directed to the target by an azimuth-elevation mirror mount. The return beam is imaged o separate ranging and tracking receivers. The ranging receiver measures time of flight of the 25-nsec laser pulse with range accuracies of +/-15 cm. The tracking receiver uses a quadrant photodiode followed by matched log video amplifiers and achieves a tracking accuracy of +/-0.1 mrad. An optical dynamic range of 30 dB is provided to minimize error due to scintillation. Also, 80 dB of optical dynamic range is provided by adjustable neutral density filters to compensate for changes in target range. PMID:20111495

  20. 2008 NASA Range Safety Annual Report

    NASA Technical Reports Server (NTRS)

    Lamoreaux, Richard W.

    2008-01-01

    Welcome to the 2008 edition of the NASA Range Safety Annual Report. Funded by NASA Headquarters, this report provides a NASA Range Safety overview for current and potential range users. This year, along with full length articles concerning various subject areas, we have provided updates to standard subjects with links back to the 2007 original article. Additionally, we present summaries from the various NASA Range Safety Program activities that took place throughout the year, as well as information on several special projects that may have a profound impact on the way we will do business in the future. The sections include a program overview and 2008 highlights of Range Safety Training; Range Safety Policy; Independent Assessments and Common Risk Analysis Tools Development; Support to Program Operations at all ranges conducting NASA launch operations; a continuing overview of emerging Range Safety-related technologies; Special Interests Items that include recent changes in the ELV Payload Safety Program and the VAS explosive siting study; and status reports from all of the NASA Centers that have Range Safety responsibilities. As is the case each year, contributors to this report are too numerous to mention, but we thank individuals from the NASA Centers, the Department of Defense, and civilian organizations for their contributions. We have made a great effort to include the most current information available. We recommend that this report be used only for guidance and that the validity and accuracy of all articles be verified for updates. This is the third year we have utilized this web-based format for the annual report. We continually receive positive feedback on the web-based edition, and we hope you enjoy this year's product as well. It has been a very busy and productive year on many fronts as you will note as you review this report. Thank you to everyone who contributed to make this year a successful one, and I look forward to working with all of you in the

  1. A 4 V, ns-range pulse generator for the test of Cherenkov Telescopes readout electronics

    NASA Astrophysics Data System (ADS)

    Antoranz, P.; Vegas, I.; Miranda, J. M.

    2010-08-01

    We present in this paper the design, fabrication and verification of a ns-range pulse generator based on a Step Recovery Diode (SRD). This device needs only a 5 V DC power supply, delivers 1 ns pulses with peak amplitudes in excess of 4 V and features state of the art jitter figures. In addition, the pulser contains a trigger channel. The long standing problem of the SRD simulation via circuital analysis is addressed. It is shown that the dynamic properties of the Step Recovery Diode can accurately be reproduced via a small signal circuital simulation for the rise times needed in a ns-range pulser. It is also demonstrated that strong inaccuracies in the pulse shape prediction are obtained if the wave propagation through the lines typically used in this type of circuits is simulated by a simple Transverse Electromagnetic Mode (TEM) line model. Instead, it is necessary to account for non-TEM effects. By means of broadband resistive power splitters and high dynamic range amplifiers, a prototype of 4 channels was also fabricated. This prototype is particularly useful for testing the readout electronics of Cherenkov Telescopes, but additional applications to other large-scale experiments are expected, any of those where calibration or verification with compact ns-range pulsers featuring low jitter, large dynamic ranges and multichannel operation is needed. In addition, the fabrication cost of this pulser is almost negligible as compared with bulky, commercially available waveform generators, which rarely deliver ns pulses in excess of 3 V. Furthermore, the small size of the pulser presented here and its low power consumption allow an easy integration into more complex systems.

  2. Dual-exposure technique for extending the dynamic range of x-ray flat panel detectors

    NASA Astrophysics Data System (ADS)

    Sisniega, A.; Abella, M.; Desco, M.; Vaquero, J. J.

    2014-01-01

    This work presents an approach to extend the dynamic range of x-ray flat panel detectors by combining two acquisitions of the same sample taken with two different x-ray photon flux levels and the same beam spectral configuration. In order to combine both datasets, the response of detector pixels was modelled in terms of mean and variance using a linear model. The model was extended to take into account the effect of pixel saturation. We estimated a joint probability density function (j-pdf) of the pixel values by assuming that each dataset follows an independent Gaussian distribution. This j-pdf was used for estimating the final pixel value of the high-dynamic-range dataset using a maximum likelihood method. The suitability of the pixel model for the representation of the detector signal was assessed using experimental data from a small-animal cone-beam micro-CT scanner equipped with a flat panel detector. The potential extension in dynamic range offered by our method was investigated for generic flat panel detectors using analytical expressions and simulations. The performance of the proposed dual-exposure approach in realistic imaging environments was compared with that of a regular single-exposure technique using experimental data from two different phantoms. Image quality was assessed in terms of signal-to-noise ratio, contrast, and analysis of profiles drawn on the images. The dynamic range, measured as the ratio between the exposure for saturation and the exposure equivalent to instrumentation noise, was increased from 76.9 to 166.7 when using our method. Dual-exposure results showed higher contrast-to-noise ratio and contrast resolution than the single-exposure acquisitions for the same x-ray dose. In addition, image artifacts were reduced in the combined dataset. This technique to extend the dynamic range of the detector without increasing the dose is particularly suited to image samples that contain both low and high attenuation regions.

  3. Colour hologram projection with an SLM by exploiting its full phase modulation range.

    PubMed

    Jesacher, Alexander; Bernet, Stefan; Ritsch-Marte, Monika

    2014-08-25

    We demonstrate independent and simultaneous manipulation of light beams of different wavelengths by a single hologram, which is displayed on a phase-only liquid crystal spatial light modulator (SLM). The method uses the high dynamic phase modulation range of modern SLMs, which can shift the phase of each pixel in a range between 0 up to 10π, depending on the readout wavelength. The extended phase range offers additional degrees of freedom for hologram encoding. Knowing the phase modulation properties of the SLM (i.e. the so-called lookup table) in the entire exploited wavelength range, an exhaustive search algorithm allows to combine different independently calculated 2π-holograms into a multi-level hologram with a phase range extending over several multiples of 2π. The combined multi-level hologram then reconstructs the original diffractive patterns with only small phase errors at preselected wavelengths, thus projecting the desired image fields almost without any crosstalk. We demonstrate this feature by displaying a static hologram at an SLM which is read out with an incoherent red-green-blue (RGB) beam, projecting a color image at a camera chip. This is done for both, a Fourier setup which needs a lens for image focusing, and in a "lensless" Fresnel setup, which also avoids the appearance of a focused zero-order spot in the image center. The experimentally obtained efficiency of a two-colour combination is on the order of 83% for each wavelength, with a crosstalk level between the two colour channels below 2%, whereas a three-colour combination still reaches an efficiency of about 60% and a crosstalk level below 5%. PMID:25321258

  4. Ranging performance of satellite laser altimeters

    NASA Technical Reports Server (NTRS)

    Gardner, Chester S.

    1992-01-01

    Detailed expressions for the range and pulse width measurement accuracies are developed and used to evaluate the ranging performances of several satellite laser altimeters currently under development by NASA for launch during the next decade. The analysis includes the effects of the target surface characteristics, spacecraft pointing jitter, and waveform digitizer characteristics. The results show that ranging accuracy is critically dependent on the pointing accuracy and stability of the altimeter especially over high relief terrain where surface slopes are large. At typical orbital altitudes of several hundred kilometers, single-shot accuracies of a few centimeters can be achieved only when the pointing jitter is on the order of 10 microrad or less.

  5. An improved light source for laser ranging

    NASA Technical Reports Server (NTRS)

    Hamal, Karel; Richardson, Martin

    1993-01-01

    The development of a new laser material, Cr-doped LiSAF, makes possible the development of a laser source for satellite ranging systems that is more superior in performance capabilities than current Nd:YAG-based laser sources. This new material offers the potential of shorter pulses and more preferable wavelengths (850 and 425 nm) than multiwavelength Nd:YAG systems, leading to superior ranging resolution and greater detection sensitivity. We are embarking on a feasibility study of a two-wavelength, mode-locked laser system based on Cr:LiSAF, providing shorter pulses for improved ranging resolution.

  6. Passive long range acousto-optic sensor

    NASA Astrophysics Data System (ADS)

    Slater, Dan

    2006-08-01

    Alexander Graham Bell's photophone of 1880 was a simple free space optical communication device that used the sun to illuminate a reflective acoustic diaphragm. A selenium photocell located 213 m (700 ft) away converted the acoustically modulated light beam back into sound. A variation of the photophone is presented here that uses naturally formed free space acousto-optic communications links to provide passive multichannel long range acoustic sensing. This system, called RAS (remote acoustic sensor), functions as a long range microphone with a demonstrated range in excess of 40 km (25 miles).

  7. Remote sensing applications for range management

    NASA Technical Reports Server (NTRS)

    Haas, R. H.

    1981-01-01

    The use of satellite information for range management is discussed. The use of infrared photography and color photography for analysis of vegetation cover is described. The methods of interpreting LANDSAT imagery are highlighted and possible applications of such interpretive methods to range management are considered. The concept of using LANDSAT as a sampling frame for renewable natural resource inventories was examined. It is concluded that a blending of LANDSAT vegetation data with soils and digital terrain data, will define a basic sampling unit that is appropriate for range management utilization.

  8. Triad interactions in the dissipation range

    NASA Technical Reports Server (NTRS)

    Kida, S.; Kraichnan, Robert H.; Rogallo, R. S.; Waleffe, F.; Zhou, Y.

    1992-01-01

    Nonlocality of the triad interactions in the dissipation range of developed turbulence is investigated by numerical simulation and the quasi-normal theories. It is found that the energy transfer is dominated by nonlocal triad interactions over the wavenumber range 0.1 is less than k/k(sub d) is less than 4, where k(sub d) is the Kolmogorov wave number. The nonlocality of the interaction has a close relation with the power of an algebraic prefactor of the exponential decay of the energy spectrum in the far-dissipation range.

  9. Techniques for optically compressing light intensity ranges

    DOEpatents

    Rushford, M.C.

    1989-03-28

    A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter. 18 figs.

  10. Techniques for optically compressing light intensity ranges

    DOEpatents

    Rushford, Michael C.

    1989-01-01

    A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter.

  11. Estimability and simple dynamical analyses of range (range-rate range-difference) observations to artificial satellites. [laser range observations to LAGEOS using non-Bayesian statistics

    NASA Technical Reports Server (NTRS)

    Vangelder, B. H. W.

    1978-01-01

    Non-Bayesian statistics were used in simulation studies centered around laser range observations to LAGEOS. The capabilities of satellite laser ranging especially in connection with relative station positioning are evaluated. The satellite measurement system under investigation may fall short in precise determinations of the earth's orientation (precession and nutation) and earth's rotation as opposed to systems as very long baseline interferometry (VLBI) and lunar laser ranging (LLR). Relative station positioning, determination of (differential) polar motion, positioning of stations with respect to the earth's center of mass and determination of the earth's gravity field should be easily realized by satellite laser ranging (SLR). The last two features should be considered as best (or solely) determinable by SLR in contrast to VLBI and LLR.

  12. Ranging performance of satellite laser altimeters

    NASA Technical Reports Server (NTRS)

    Gardner, Chester S.

    1992-01-01

    Topographic mapping of the earth, moon and planets can be accomplished with high resolution and accuracy using satellite laser altimeters. These systems employ nanosecond laser pulses and microradian beam divergences to achieve submeter vertical range resolution from orbital altitudes of several hundred kilometers. Here, we develop detailed expressions for the range and pulse width measurement accuracies and use the results to evaluate the ranging performances of several satellite laser altimeters currently under development by NASA for launch during the next decade. Our analysis includes the effects of the target surface characteristics, spacecraft pointing jitter and waveform digitizer characteristics. The results show that ranging accuracy is critically dependent on the pointing accuracy and stability of the altimeter especially over high relief terrain where surface slopes are large. At typical orbital altitudes of several hundred kilometers, single-shot accuracies of a few centimeters can be achieved only when the pointing jitter is on the order of 10 mu rad or less.

  13. Shock absorber operates over wide range

    NASA Technical Reports Server (NTRS)

    Creasy, W. K.; Jones, J. C.

    1965-01-01

    Piston-type hydraulic shock absorber, with a metered damping system, operates over a wide range of kinetic energy loading rates. It is used for absorbing shock and vibration on mounted machinery and heavy earth-moving equipment.

  14. JOINT SMALL-ARMS RANGE REMEDIATION

    EPA Science Inventory

    This Environmental Security Technology Certification Program (ESTCP) demonstration conducted by the Naval Facilities Engineering Service Center (NFESC) and the Army Environmental Center (AEC) removed lead and other heavy metals from small-arms range soils by a combination of phys...

  15. Quaternionic Numerical Ranges of Normal Quaternion Matrices

    SciTech Connect

    Feng Lianggui

    2009-09-09

    By the Jordan canonical block-entry form introduced in this paper, a practical method of determining the convexity and an estimation of the location on the quaternionic numerical range are given for a normal quaternion matrix.

  16. Universal time - Results from lunar laser ranging

    NASA Technical Reports Server (NTRS)

    King, R. W.; Counselman, C. C., III; Shapiro, I. I.

    1978-01-01

    A least squares analysis of lunar laser ranging observations from the McDonald Observatory is used to estimate universal time. In addition to the ranging observations, the analysis simultaneously takes into account the parameters representing the locations of McDonald and the lunar retroreflectors, the orbits of the earth and the moon, and the moon's physical libration. The root-mean-square of the postfit range residuals for the 5-year period from October 1970 to November 1975 is 28 cm. The results are compared with those obtained by the Bureau International de l'Heure and by Stolz et al. (1976), and the reasons for discrepancies are discussed. It is suggested that problems in modeling the moon's motion make difficult the determination of UT with the accuracy inherent in the ranging observations.

  17. Intentionally Short-Range Communications (ISRC)

    NASA Astrophysics Data System (ADS)

    Yen, J.; Poirier, P.; Obrien, M.

    1994-02-01

    The U.S. Marine Corps (USMC) desired to develop short-range communications links whose ranges are intentionally limited to very short distances. These links support tactical missions such as LAN Backbone, Wideband Data Link, and Company Radio. The short-range limitation arises from the need for low probability of detection and intercept (LPD/LPI). Since the detection of an undecipherable transmission would still provide an enemy with information regarding transmitter location and allow him to take countermeasures, the Marine Corps Systems Command (MARCORSYSCOM) is sponsoring the development of technologies that can be LPD by their very nature. The Intentionally Short-Range Communications (ISRC) project at the Naval Command, Control and Ocean Surveillance Center (NCCOSC) RDT&E Division (NRaD) is pursuing feasibility studies for these USMC missions based on such technologies as ultraviolet (LTV) lamps, UV lasers, infrared (IR) lasers, millimeter waves and direct sequence spread spectrum (DSSS) at radio frequencies.

  18. Photoresistance analog multiplier has wide range

    NASA Technical Reports Server (NTRS)

    Hartenstein, R. G.

    1965-01-01

    Photoactivated bridge facilitates equal performance of analog multipliers over a wide frequency range. The multiplier operates from direct current to an upper frequency limited by either the light source or the closed-loop amplifier.

  19. Recent firing range suicides in South Australia.

    PubMed

    Austin, Amy E; van den Heuvel, Corinna; Heath, Karen; Gilbert, John D; Byard, Roger W

    2012-11-01

    Two cases are reported from South Australia, where deaths occurred that were due to single self-inflicted gunshot wounds to the head in individuals who were visiting indoor firearm ranges. Case 1: A 54-year-old man visiting an indoor firing range placed a .357 magnum handgun to his head and fired one shot. Case 2: A 23-year-old woman who was being instructed in firearm usage at an indoor firing range placed a 9 mm handgun to her head and fired one shot. In both cases, deaths were due to cerebral laceration with skull fracture. Firing ranges may be utilized by individuals who are seeking weapons for suicide attempts, and suicide may be successfully undertaken at such locations even while a victim is under direct supervision. In jurisdictions, where firearm ownership is strictly legislated, it may be that clubs can inadvertently provide access to firearms for this type of activity. PMID:22471964

  20. Full range pawl and ratchet clutch

    NASA Astrophysics Data System (ADS)

    Zobott, Keith D.; Burch, Darrel W.

    1992-10-01

    The full-range pawl-and-ratchet clutch will permit very versatile operation of an air turbine starter. The need for a full-range pawl-and-ratchet clutch arises from various aircraft anomalies that may lead to ordinary clutch failures and therefore cause unnecessary delays for commercial as well as military aircraft. Air turbine starters containing a full-range pawl-and-ratchet clutch permit running engagement starts of aircraft jet engines at any speed from zero to above 10,000 rpm. The starter automatically disengages from the engine after completing the start and spins down to zero rpm. The concept embodied in the full-range pawl-and-ratchet clutch will provide a new generation of aircraft starters and represents a revolutionary advancement in the state of the art for air turbine starters.

  1. High range resolution micro-Doppler analysis

    NASA Astrophysics Data System (ADS)

    Cammenga, Zachary A.; Smith, Graeme E.; Baker, Christopher J.

    2015-05-01

    This paper addresses use of the micro-Doppler effect and the use of high range-resolution profiles to observe complex targets in complex target scenes. The combination of micro-Doppler and high range-resolution provides the ability to separate the motion of complex targets from one another. This ability leads to the differentiation of targets based on their micro-Doppler signatures. Without the high-range resolution, this would not be possible because the individual signatures would not be separable. This paper also addresses the use of the micro-Doppler information and high range-resolution profiles to generate an approximation of the scattering properties of a complex target. This approximation gives insight into the structure of the complex target and, critically, is created without using a pre-determined target model.

  2. Comparative analysis of planetary laser ranging concepts

    NASA Astrophysics Data System (ADS)

    Dirkx, D.; Bauer, S.; Noomen, R.; Vermeersen, B. L. A.; Visser, P. N.

    2014-12-01

    Laser ranging is an emerging technology for tracking interplanetary missions, offering improved range accuracy and precision (mm-cm), compared to existing DSN tracking. The ground segment uses existing Satellite Laser Ranging (SLR) technology, whereas the space segment is modified with an active system. In a one-way system, such as that currently being used on the LRO spacecraft (Zuber et al., 2010), only an active detector is required on the spacecraft. For a two-way system, such as that tested by using the laser altimeter system on the MESSENGER spacecraft en route to Mercury (Smith et al., 2006), a laser transmitter system is additionally placed on the space segment, which will asynchronously fire laser pulses towards the ground stations. Although the one-way system requires less hardware, clock errors on both the space and ground segments will accumulate over time, polluting the range measurements. For a two-way system, the range measurements are only sensitive to clock errors integrated over the the two-way light time.We investigate the performance of both one- and two-way laser range systems by simulating their operation. We generate realizations of clock error time histories from Allan variance profiles, and use them to create range measurement error profiles. We subsequently perform the orbit determination process from this data to quanitfy the system's performance. For our simulations, we use two test cases: a lunar orbiter similar to LRO and a Phobos lander similar to the Phobos Laser Ranging concept (Turyshev et al., 2010). For the lunar orbiter, we include an empirical model for unmodelled non-gravitational accelerations in our truth model to include errors ihe dynamics. We include the estimation of clock parameters over a number of arc lengths for our simulations of the one-way range system and use a variety of state arc durations for the lunar orbiter simulations.We perform Monte Carlo simulations and generate true error distributions for both

  3. Makran Mountain Range, Iran and Pakistan

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The long folded mountain ridges and valleys of the coastal Makran Ranges of Iran and Pakistan (26.0N, 63.0E) illustrate the classical Trellis type of drainage pattern, common in this region. The Dasht River and its tributaries is the principal drainage network for this area. To the left, the continental drift of the northward bound Indian sub-continent has caused the east/west parallel ranges to bend in a great northward arc.

  4. Ground based laser ranging for satellite location

    NASA Technical Reports Server (NTRS)

    Gilbreath, G. C.; Newby, Harold D.

    1993-01-01

    In this article, we describe a new satellite laser ranging capability which is a joint effort between the Naval Research Laboratory and Air Force Optical Tracking Facility at Malabar, Florida. Initial measurements off LAGEOS indicate that uncorrected radial range rms values of 8 mm are readily achievable. The number of photoelectron counts are on the order of 180 which are off by an order of magnitude from predicted values.

  5. Poisson filtering of laser ranging data

    NASA Technical Reports Server (NTRS)

    Ricklefs, Randall L.; Shelus, Peter J.

    1993-01-01

    The filtering of data in a high noise, low signal strength environment is a situation encountered routinely in lunar laser ranging (LLR) and, to a lesser extent, in artificial satellite laser ranging (SLR). The use of Poisson statistics as one of the tools for filtering LLR data is described first in a historical context. The more recent application of this statistical technique to noisy SLR data is also described.

  6. Entrainment ranges of forced phase oscillators.

    PubMed

    Previte, Joseph P; Sheils, Natalie; Hoffman, Kathleen A; Kiemel, Tim; Tytell, Eric D

    2011-04-01

    In the vertebrate spinal cord, a neural circuit called the central pattern generator produces the basic locomotory rhythm. Short and long distance intersegmental connections serve to maintain coordination along the length of the body. As a way of examining the influence of such connections, we consider a model of a chain of coupled phase oscillators in which one oscillator receives a periodic forcing stimulus. For a certain range of forcing frequencies, the chain will match the stimulus frequency, a phenomenon called entrainment. Motivated by recent experiments in lampreys, we derive analytical expressions for the range of forcing frequencies that entrain the chain, and how that range depends on the forcing location. For short intersegmental connections, in which an oscillator is connected only to its nearest neighbors, we describe two ways in which entrainment is lost: internally, in which oscillators within the chain no longer oscillate at the same frequency; and externally, in which the the chain no longer has the same frequency as the forcing. By analyzing chains in which every oscillator is connected to every other oscillator (i.e., all-to-all connections), we show that the presence of connections with lengths greater than one do not necessarily change the entrainment ranges based on the nearest-neighbor model. We derive a criterion for the ratio of connection strengths under which the connections of length greater than one do not change the entrainment ranges produced in the nearest-neighbor model, provided entrainment is lost externally. However, when this criterion holds, the range of entrained frequencies is a monotonic function of forcing location, unlike experimental results, in which entrainment ranges are larger near the middle of the chain than at the ends. Numerically, we show that similar non-monotonic entrainment ranges are possible if the ratio criterion does not hold, suggesting that in the lamprey central pattern generator, intersegmental

  7. Positron range estimations with PeneloPET

    NASA Astrophysics Data System (ADS)

    Cal-González, J.; Herraiz, J. L.; España, S.; Corzo, P. M. G.; Vaquero, J. J.; Desco, M.; Udias, J. M.

    2013-08-01

    Technical advances towards high resolution PET imaging try to overcome the inherent physical limitations to spatial resolution. Positrons travel in tissue until they annihilate into the two gamma photons detected. This range is the main detector-independent contribution to PET imaging blurring. To a large extent, it can be remedied during image reconstruction if accurate estimates of positron range are available. However, the existing estimates differ, and the comparison with the scarce experimental data available is not conclusive. In this work we present positron annihilation distributions obtained from Monte Carlo simulations with the PeneloPET simulation toolkit, for several common PET isotopes (18F, 11C, 13N, 15O, 68Ga and 82Rb) in different biological media (cortical bone, soft bone, skin, muscle striated, brain, water, adipose tissue and lung). We compare PeneloPET simulations against experimental data and other simulation results available in the literature. To this end the different positron range representations employed in the literature are related to each other by means of a new parameterization for positron range profiles. Our results are generally consistent with experiments and with most simulations previously reported with differences of less than 20% in the mean and maximum range values. From these results, we conclude that better experimental measurements are needed, especially to disentangle the effect of positronium formation in positron range. Finally, with the aid of PeneloPET, we confirm that scaling approaches can be used to obtain universal, material and isotope independent, positron range profiles, which would considerably simplify range correction.

  8. Topological defects with long-range interactions

    NASA Astrophysics Data System (ADS)

    Mello, B. A.; González, J. A.; Guerrero, L. E.; López-Atencio, E.

    1998-07-01

    We investigate a modified sine-Gordon equation which possesses soliton solutions with long-range interaction. We introduce a generalized version of the Ginzburg-Landau equation which supports long-range topological defects in D = 1 and D > 1. The interaction force between the defects decays so slowly that it is possible to enter the non-extensivity regime. These results can be applied to non-equilibrium systems, pattern formation and growth models.

  9. Determining Spatial Coordinates By Laser Ranging

    NASA Technical Reports Server (NTRS)

    Schumacher, Larry L.

    1990-01-01

    Three range-measuring lasers arranged in triangle measure location of point. Set of three measurements of distances (ranges) of retroreflector on object from three rangefinders provides sufficient information to calculate coordinates of retroreflector in coordinate system defined by rangefinders. If at least three noncollinear retroreflectors attached to object, orientation of object also determined. Potential applications include observation and control of large structures, robotics, and machine vision.

  10. Orbit determination by range-only data.

    NASA Technical Reports Server (NTRS)

    Duong, N.; Winn, C. B.

    1973-01-01

    The determination of satellite orbits for use in geodesy using range-only data has been examined. A recently developed recursive algorithm for rectification of the nominal orbit after processing each observation has been tested. It is shown that when a synchronous satellite is tracked simultaneously with a subsynchronous geodetic target satellite, the orbits of each may be readily determined by processing the range information. Random data errors and satellite perturbations are included in the examples presented.

  11. Programmable near-infrared ranging system

    DOEpatents

    Everett, Jr., Hobart R.

    1989-01-01

    A high angular resolution ranging system particularly suitable for indoor plications involving mobile robot navigation and collision avoidance uses a programmable array of light emitters that can be sequentially incremented by a microprocessor. A plurality of adjustable level threshold detectors are used in an optical receiver for detecting the threshold level of the light echoes produced when light emitted from one or more of the emitters is reflected by a target or object in the scan path of the ranging system.

  12. Passive ranging through the Earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Hasson, Victor H.; Dupuis, Christopher R.

    2002-02-01

    Many luminous sources provide continuous or quasi-continuous radiation at near IR and longer wavelengths. The radiation continuum serves as a source of background photons, which can be used for discrete line-of-site absorption measurements by-known atmospheric constituents. The intensity ratio is uniquely determined by the absorption coefficient and range, is independent of broadband attenuations and scattering. The absorption coefficients are known and/or can be accurately calculated for a wide range of practical viewing conditions (i.e., sensor height, viewing angle, etc.). Hence, the intensity ratio and/or integrated intensity ratio can be used to uniquely derive the range of the radiating source. Fabry-Perot interferometers can provide the high throughputs and resolving powers required in compact packages. The measurements and analyses show that ranging accuracies representing down to 1 - 2% of the total range should be achievable at stand-off ranges of upto hundreds of kilometers depending on the size of the collection optics, brightness of the source and available observation times. The paper will provide an overview of the patented Textron concepts, trade-offs associated with instrument resolving powers and hardware implementation issues.

  13. Exploration and mating range in African Pygmies.

    PubMed

    Cavalli-Sforza, L L; Hewlett, B

    1982-07-01

    The distributions of exploration range and of mating range were studied among Aka Pygmies of the Central African Republic. Exploration range is defined and methods of estimation for single individuals suggested. A simple exponential distribution is found for individual Aka Pygmies, with variation of exploration range (the parameter defining mobility) with sex, age and ethnic affiliation. Distribution of distances from birthplace and place of residence are compared and show modest differences. The frequency of visits to a given place has also been studied. The average distance between birthplaces of mates is very similar to the mean exploration range. Correlations between individual exploration and mating ranges suggest that it is the male who may be choosing a marriage partner among Pygmies. A theory by Boyce, Küchemann & Harrison (1967) on the relations between "neighbourhood knowledge" and mating distance is inapplicable because of its reliance on the Pareto distribution, which does not apply in the present case, and of other unnecessary assumptions, but the general principle of a close relationship between exploratory activity and mating distance seems valid, at least in the present case. Suggestions are made for causes for the difference between the present distributions and those with other shapes observed in less primitive economies. PMID:7125597

  14. Ranging/tracking system for proximity operations

    NASA Technical Reports Server (NTRS)

    Nilsen, P.; Udalov, S.

    1982-01-01

    The hardware development and testing phase of a hand held radar for the ranging and tracking for Shuttle proximity operations are considered. The radar is to measure range to a 3 sigma accuracy of 1 m (3.28 ft) to a maximum range of 1850 m (6000 ft) and velocity to a 3 sigma accuracy of 0.03 m/s (0.1 ft/s). Size and weight are similar to hand held radars, frequently seen in use by motorcycle police officers. Meeting these goals for a target in free space was very difficult to obtain in the testing program; however, at a range of approximately 700 m, the 3 sigma range error was found to be 0.96 m. It is felt that much of this error is due to clutter in the test environment. As an example of the velocity accuracy, at a range of 450 m, a 3 sigma velocity error of 0.02 m/s was measured. The principles of the radar and recommended changes to its design are given. Analyses performed in support of the design process, the actual circuit diagrams, and the software listing are included.

  15. Conductance measurement circuit with wide dynamic range

    NASA Technical Reports Server (NTRS)

    Mount, Bruce E. (Inventor); Von Esch, Myron (Inventor)

    1994-01-01

    A conductance measurement circuit to measure conductance of a solution under test with an output voltage proportional to conductance over a 5-decade range, i.e., 0.01 uS to 1000 uS or from 0.1 uS to 10,000 uS. An increase in conductance indicates growth, or multiplication, of the bacteria in the test solution. Two circuits are used each for an alternate half-cycle time periods of an alternate squarewave in order to cause alternate and opposite currents to be applied to the test solution. The output of one of the two circuits may be scaled for a different range optimum switching frequency dependent upon the solution conductance and to enable uninterrupted measurement over the complete 5-decade range. This circuitry provides two overlapping ranges of conductance which can be read simultaneously without discontinuity thereby eliminating range switching within the basic circuitry. A VCO is used to automatically change the operating frequency according to the particular value of the conductance being measured, and comparators indicate which range is valid and also facilitate computer-controlled data acquisition. A multiplexer may be used to monitor any number of solutions under test continuously.

  16. Discrete range clustering using Monte Carlo methods

    NASA Technical Reports Server (NTRS)

    Chatterji, G. B.; Sridhar, B.

    1993-01-01

    For automatic obstacle avoidance guidance during rotorcraft low altitude flight, a reliable model of the nearby environment is needed. Such a model may be constructed by applying surface fitting techniques to the dense range map obtained by active sensing using radars. However, for covertness, passive sensing techniques using electro-optic sensors are desirable. As opposed to the dense range map obtained via active sensing, passive sensing algorithms produce reliable range at sparse locations, and therefore, surface fitting techniques to fill the gaps in the range measurement are not directly applicable. Both for automatic guidance and as a display for aiding the pilot, these discrete ranges need to be grouped into sets which correspond to objects in the nearby environment. The focus of this paper is on using Monte Carlo methods for clustering range points into meaningful groups. One of the aims of the paper is to explore whether simulated annealing methods offer significant advantage over the basic Monte Carlo method for this class of problems. We compare three different approaches and present application results of these algorithms to a laboratory image sequence and a helicopter flight sequence.

  17. Secondary sympatry caused by range expansion informs on the dynamics of microendemism in a biodiversity hotspot.

    PubMed

    Nattier, Romain; Grandcolas, Philippe; Elias, Marianne; Desutter-Grandcolas, Laure; Jourdan, Hervé; Couloux, Arnaud; Robillard, Tony

    2012-01-01

    Islands are bounded areas where high endemism is explained either by allopatric speciation through the fragmentation of the limited amount of space available, or by sympatric speciation and accumulation of daughter species. Most empirical evidence point out the dominant action of allopatric speciation. We evaluate this general view by looking at a case study where sympatric speciation is suspected. We analyse the mode, tempo and geography of speciation in Agnotecous, a cricket genus endemic to New Caledonia showing a generalized pattern of sympatry between species making sympatric speciation plausible. We obtained five mitochondrial and five nuclear markers (6.8 kb) from 37 taxa corresponding to 17 of the 21 known extant species of Agnotecous, and including several localities per species, and we conducted phylogenetic and dating analyses. Our results suggest that the diversification of Agnotecous occurred mostly through allopatric speciation in the last 10 Myr. Highly microendemic species are the most recent ones (<2 Myr) and current sympatry is due to secondary range expansion after allopatric speciation. Species distribution should then be viewed as a highly dynamic process and extreme microendemism only as a temporary situation. We discuss these results considering the influence of climatic changes combined with intricate soil diversity and mountain topography. A complex interplay between these factors could have permitted repeated speciation events and range expansion. PMID:23139758

  18. Canine hip extension range during gait.

    PubMed

    van der Walt, A M; Stewart, A V; Joubert, K E; Bekker, P

    2008-12-01

    Assessment of canine gait is frequently used by veterinary clinicians to establish the presence of orthopaedic pain. As up to 30% of canine orthopaedic conditions affect the pelvic limb, knowledge of pelvic limb biomechanics during gait is very important. Previous studies have investigated the biomechanics at the tarsus and stifle, but little information is available regarding hip motion during gait. The aim of this study was to determine the maximum hip extension range achieved during the stance phase of gait in normal canines. In addition, this study aimed to determine the difference between maximum passive hip extension and maximum hip extension during gait. Using a sample of 30 morphologically similar normal dogs, mean maximum passive hip extension was measured using a goniometer and mean maximum hip extension range during gait was determined videographically. Inter- and intra-assessor reliability studies performed at the start of the study showed that the measurement tools and techniques used in this study were valid and reliable. The goniometric data showed that mean maximum passive hip extension range was 162.44 degrees (+/-3.94) with no significant difference between the left and the right hind limbs. The videographic data showed that mean maximum hip extension range during gait was 119.9 degrees (+/-9.26) with no significant difference between the left and right hind limbs. The results of this study provided reference values for active and passive hip extension range and showed that the degree of hip extension range required for normal gait is significantly less than maximum passive hip extension range. PMID:19496317

  19. Servomotor and Controller Having Large Dynamic Range

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Howard, David E.; Smith, Dennis A.; Dutton, Ken; Paulson, M. Scott

    2007-01-01

    A recently developed micro-commanding rotational-position-control system offers advantages of less mechanical complexity, less susceptibility to mechanical resonances, less power demand, less bulk, less weight, and lower cost, relative to prior rotational-position-control systems based on stepping motors and gear drives. This system includes a digital-signal- processor (DSP)-based electronic controller, plus a shaft-angle resolver and a servomotor mounted on the same shaft. Heretofore, micro-stepping has usually been associated with stepping motors, but in this system, the servomotor is micro-commanded in response to rotational-position feedback from the shaft-angle resolver. The shaft-angle resolver is of a four-speed type chosen because it affords four times the resolution of a single-speed resolver. A key innovative aspect of this system is its position-feedback signal- conditioning circuits, which condition the resolver output signal for multiple ranges of rotational speed. In the preferred version of the system, two rotational- speed ranges are included, but any number of ranges could be added to expand the speed range or increase resolution in particular ranges. In the preferred version, the resolver output is conditioned with two resolver-to-digital converters (RDCs). One RDC is used for speeds from 0.00012 to 2.5 rpm; the other RDC is used for speeds of 2.5 to 6,000 rpm. For the lower speed range, the number of discrete steps of RDC output per revolution was set at 262,144 (4 quadrants at 16 bits per quadrant). For the higher speed range, the number of discrete steps per revolution was set at 4,096 (4 quadrants at 10 bits per quadrant).

  20. Individual differences in BEV drivers' range stress during first encounter of a critical range situation.

    PubMed

    Franke, Thomas; Rauh, Nadine; Krems, Josef F

    2016-11-01

    It is commonly held that range anxiety, in the form of experienced range stress, constitutes a usage barrier, particularly during the early period of battery electric vehicle (BEV) usage. To better understand factors that play a role in range stress during this critical period of adaptation to limited-range mobility, we examined individual differences in experienced range stress in the context of a critical range situation. In a field experiment, 74 participants drove a BEV on a 94-km round trip, which was tailored to lead to a critical range situation (i.e., small available range safety buffer). Higher route familiarity, trust in the range estimation system, system knowledge, subjective range competence, and internal control beliefs in dealing with technology were clearly related to lower experienced range stress; emotional stability (i.e., low neuroticism) was partly related to lower range stress. These results can inform strategies aimed at reducing range stress during early BEV usage, as well as contribute to a better understanding of factors that drive user experience in low-resource systems, which is a key topic in the field of green ergonomics. PMID:26456746

  1. Protected areas facilitate species' range expansions.

    PubMed

    Thomas, Chris D; Gillingham, Phillipa K; Bradbury, Richard B; Roy, David B; Anderson, Barbara J; Baxter, John M; Bourn, Nigel A D; Crick, Humphrey Q P; Findon, Richard A; Fox, Richard; Hodgson, Jenny A; Holt, Alison R; Morecroft, Mike D; O'Hanlon, Nina J; Oliver, Tom H; Pearce-Higgins, James W; Procter, Deborah A; Thomas, Jeremy A; Walker, Kevin J; Walmsley, Clive A; Wilson, Robert J; Hill, Jane K

    2012-08-28

    The benefits of protected areas (PAs) for biodiversity have been questioned in the context of climate change because PAs are static, whereas the distributions of species are dynamic. Current PAs may, however, continue to be important if they provide suitable locations for species to colonize at their leading-edge range boundaries, thereby enabling spread into new regions. Here, we present an empirical assessment of the role of PAs as targets for colonization during recent range expansions. Records from intensive surveys revealed that seven bird and butterfly species have colonized PAs 4.2 (median) times more frequently than expected from the availability of PAs in the landscapes colonized. Records of an additional 256 invertebrate species with less-intensive surveys supported these findings and showed that 98% of species are disproportionately associated with PAs in newly colonized parts of their ranges. Although colonizing species favor PAs in general, species vary greatly in their reliance on PAs, reflecting differences in the dependence of individual species on particular habitats and other conditions that are available only in PAs. These findings highlight the importance of current PAs for facilitating range expansions and show that a small subset of the landscape receives a high proportion of colonizations by range-expanding species. PMID:22893689

  2. Testing gravitational physics with satellite laser ranging

    NASA Astrophysics Data System (ADS)

    Ciufolini, Ignazio; Paolozzi, Antonio; Pavlis, Erricos C.; Ries, John; Koenig, Rolf; Matzner, Richard; Sindoni, Giampiero; Neumeyer, Hans

    2011-08-01

    Laser ranging, both Lunar (LLR) and Satellite Laser Ranging (SLR), is one of the most accurate techniques to test gravitational physics and Einstein's theory of General Relativity. Lunar Laser Ranging has provided very accurate tests of both the strong equivalence principle, at the foundations of General Relativity, and of the weak equivalence principle, at the basis of any metric theory of gravity; it has provided strong limits to the values of the so-called PPN (Parametrized Post-Newtonian) parameters, that are used to test the post-Newtonian limit of General Relativity, strong limits to conceivable deviations to the inverse square law for very weak gravity and accurate measurements of the geodetic precession, an effect predicted by General Relativity. Satellite laser ranging has provided strong limits to deviations to the inverse square gravity law, at a different range with respect to LLR, and in particular has given the first direct test of the gravitomagnetic field by measuring the gravitomagnetic shift of the node of a satellite, a frame-dragging effect also called Lense-Thirring effect. Here, after an introduction to gravitomagnetism and frame-dragging, we describe the latest results in measuring the Lense-Thirring effect using the LAGEOS satellites and the latest gravity field models obtained by the space mission GRACE. Finally, we describe an update of the LARES (LAser RElativity Satellite) mission. LARES is planned for launch in 2011 to further improve the accuracy in the measurement of frame-dragging.

  3. Two wavelength satellite laser ranging using SPAD

    NASA Technical Reports Server (NTRS)

    Prochazka, Ivan; Hamal, Karel; Jelinkova, Helena; Kirchner, Georg; Koidl, F.

    1993-01-01

    When ranging to satellites with lasers, there are several principal contributions to the error budget: from the laser ranging system on the ground, from the satellite retroarray geometry, and from the atmosphere. Using a single wavelength, we have routinely achieved a ranging precision of 8 millimeters when ranging to the ERS-1 and Starlette satellites. The systematic error of the atmosphere, assuming the existing dispersion models, is expected to be of the order of 1 cm. Multiple wavelengths ranging might contribute to the refinement of the existing models. Taking into account the energy balance, the existing picosecond lasers and the existing receiver and detection technology, several pairs or multiple wavelengths may be considered. To be able to improve the atmospheric models to the subcentimeter accuracy level, the differential time interval (DTI) has to be determined within a few picoseconds depending on the selected wavelength pair. There exist several projects based on picosecond lasers as transmitters and on two types of detection techniques: one is based on photodetectors, like photomultipliers or photodiodes connected to the time interval meters. Another technique is based on the use of a streak camera as an echo signal detector, temporal analyzer, and time interval vernier. The temporal analysis at a single wavelength using the streak camera showed the complexity of the problem.

  4. Long range target discrimination using UV fluorescence

    NASA Astrophysics Data System (ADS)

    Bray, Mark; Lepley, Jason

    2011-06-01

    An active imaging system using UV fluorescence for target discrimination is proposed. The emission wavelength is characteristic of the target material and allows spectral discrimination of targets from clutter. The burst-illumination-LIDAR system transmits a laser pulse and the fluorescent return is detected with a synchronised gated imaging receiver. The short gate length (~ns) allowed by a micro-channel plate CCD reduces solar clutter. Detector noise is not the limiting factor because of the high MCP-CCD detectivity. Laser choice is constrained by the required laser pulse energy, laser size and robustness. The COTS solution identified is a diode-pumped, 4th harmonic converted, 1064nm laser. Nd:YAG, Nd:YLF and Nd:Alexandrite lasers have superior performance but require some development for this application. A pessimistic range model evaluates the optical powers. Comparison of the received fluorescent energy to the detector noise equivalent energy and the solar energy received provides the detection range limit. Performance of the proposed systems exceeds the detection range requirement for all samples evaluated and all varying conditions explored. The lowest range is for black paint with the COTS laser system and is 2860m; the best ranges exceed 5km.

  5. Devonian magmatism in Brooks Range, Alaska

    SciTech Connect

    Dillion, J.T.; Tilton, G.R.

    1985-04-01

    Devonian bimodel metaplutonic and metavolcanic rocks lie in parallel, west-trending belts in the southern Brooks Range. Overlapping distribution of the plutonic and volcanic rocks occurs in volcanic centers found south of the Doonerak window in the Wiseman, Chandalar, and Colleen quadrangles, and near the Beaver Creek pluton in the Survey Pass quadrangle. The Devonian age is interpreted from isotopic analyses of U and Pb of over 55 zircon fractions from these felsic metaigneous units. Considering concordia plots and Pb-Pb ages from over 40 discordant zircon fractions and fossil ages derived from marbles intercalated in the volcanic sequences, the authors see an age range of 360-410 Ma. The age range is attributed to variation in crystallization ages, as well as the U-Pb systematics of the Brooks Range zircons. Their overlapping age and distribution provides evidence for cogenesis of the Devonian plutonic and volcanic rocks, and also for their correlation with Devonian magmatic rocks of the North American Cordilleran. Lower intercepts on U-Pb concordia diagrams for these zircons range from 105 to 150 Ma, bracketing the end of lead loss resulting from metamorphism. The age of this metamorphic event corresponds to the Late Jurassic and earliest Cretaceous emplacement of the Angayucham terrane. U-Pb concordia plots of 15 zircon fractions from five samples of the Ernie Lake granitic gneiss bodies are explained as latest Proterozoic intrusion of granitic magma with entrained 2-Ga-old zircons, which subsequently lost lead during Mesozoic metamorphism.

  6. Passive ranging using a single IR sensor

    SciTech Connect

    Jeffrey, W.; Gobel, R.W.; Draper, J.S.

    1994-12-31

    As current defense system architectures change and downsize there is a need to accomplish more with each sensors capability. Desert Storm`s missile to aircraft and missile to missile engagements elevated the need to better cope with early and stealthy assessment of the adversaries location while providing minimal compromise to the operator. The use of stealth vehicles introduces a requirement to deploy sensors that silently assess tactical and theater issues [battle damage assessment (BDA) and theater missile defense (TMD)] without preengagement detection. IR sensor system development and high speed, parallel, distributed processing make practical the implementation of compact passive ranging packages aboard satellites and aircraft. Here, single IR Sensor Passive Ranging from an observer to a target embedded in the atmosphere exploits the effect of atmospheric attenuation of the signal. By judicious choice of wavebands the range and altitude to a target can be determined passively with a single observer. This result will be shown to be relatively insensitive to assumed atmospheric models or precise source spectral content. A detailed closed-form solution relating range (and altitude) to observed target intensities will be presented. Previous studies of this type have required either detailed knowledge of the source spectra or spectral resolution of individual rotational lines. The single sensor passive ranging methodology requires no such detailed information.

  7. Passive ranging of boost-phase missiles

    NASA Astrophysics Data System (ADS)

    Hawks, Michael; Perram, Glen

    2007-04-01

    The depth of absorption bands in observed spectra of distant, bright sources can be used to estimate range to the source. Previous efforts in this area relied on Beer's Law to estimate range from observations of infrared CO II bands, with disappointing results. A modified approach is presented that uses band models and observations of the O II absorption band near 762 nm. This band is spectrally isolated from other atmospheric bands, which enables direct estimation of molecular absorption from observed intensity. Range is estimated by comparing observed values of band-average absorption, (see manuscript), against predicted curves derived from either historical data or model predictions. Accuracy of better than 0.5% has been verified in short-range (up to 3km) experiments using a Fourier transform interferometer at 1cm -1 resolution. A conceptual design is described for a small, affordable passive ranging sensor suitable for use on tactical aircraft for missile attack warning and time-to-impact estimation. Models are used to extrapolate experimental results (using 1 cm -1 resolution data) to analyze expected performance of this filter-based system.

  8. Protected areas facilitate species’ range expansions

    PubMed Central

    Thomas, Chris D.; Gillingham, Phillipa K.; Bradbury, Richard B.; Roy, David B.; Anderson, Barbara J.; Baxter, John M.; Bourn, Nigel A. D.; Crick, Humphrey Q. P.; Findon, Richard A.; Fox, Richard; Hodgson, Jenny A.; Holt, Alison R.; Morecroft, Mike D.; O’Hanlon, Nina J.; Oliver, Tom H.; Pearce-Higgins, James W.; Procter, Deborah A.; Thomas, Jeremy A.; Walker, Kevin J.; Walmsley, Clive A.; Wilson, Robert J.; Hill, Jane K.

    2012-01-01

    The benefits of protected areas (PAs) for biodiversity have been questioned in the context of climate change because PAs are static, whereas the distributions of species are dynamic. Current PAs may, however, continue to be important if they provide suitable locations for species to colonize at their leading-edge range boundaries, thereby enabling spread into new regions. Here, we present an empirical assessment of the role of PAs as targets for colonization during recent range expansions. Records from intensive surveys revealed that seven bird and butterfly species have colonized PAs 4.2 (median) times more frequently than expected from the availability of PAs in the landscapes colonized. Records of an additional 256 invertebrate species with less-intensive surveys supported these findings and showed that 98% of species are disproportionately associated with PAs in newly colonized parts of their ranges. Although colonizing species favor PAs in general, species vary greatly in their reliance on PAs, reflecting differences in the dependence of individual species on particular habitats and other conditions that are available only in PAs. These findings highlight the importance of current PAs for facilitating range expansions and show that a small subset of the landscape receives a high proportion of colonizations by range-expanding species. PMID:22893689

  9. Short-Range Structure of Clouds Studied by High Resolution Photography From the Surface

    NASA Astrophysics Data System (ADS)

    Schwartz, S. E.; Huang, D.; Vladutescu, D. V.

    2015-12-01

    Clouds exhibit structures at a wide range of length scales. Passive radiometry from satellite shows structure on scales of tens to thousands of kilometers, but there is much structure at short spatial scales not resolved by satellite imagery. Here we use a commercial camera having high spatial resolution (~20 μrad) and high dynamic range (16 bits in each of three color channels) in narrow field-of-view (20 mrad, 110 mrad), zenith-looking mode from the surface, to examine clouds at the scale of centimeters to a few hundred meters, focusing on non-precipitating single-layer clouds during daytime. Up-looking photography of clouds from the surface affords the further advantage, relative to satellite imagery, of black background (space) with contributions to radiance only from blue sky (Rayleigh scattering), aerosols, and clouds, permitting reconstruction of observed radiance by radiation transfer modeling. Contrast between cloudy and cloud-free sky is enhanced in Red/(Red + Blue), RRB, image Figure 1, but no unique value of RRB distinguishes a pixel as cloud vs. cloud-free. Short-range variability is characterized by the autocorrelation length scale, which is not uncommonly as short as a few meters; longer range variability, such as cloud characteristic size, separation distance, and cloud spatial organization, is also characterized. Scene reconstruction yields the 2D distribution of cloud optical depth; spatial inhomogeneity is attributed mainly to horizontal variation in vertical motion of the air and resultant condensation or evaporation associated with upward or downward motion, respectively. Alternative approaches to calculation of the radiative influence of such clouds from the autocorrelation structure of the cloud field are examined. Figure 1. RGB image of zenith sky at New York City, May 22, 2015, (field of view 21 mrad corresponding to 56 m at cloud altitude 2.6 km) showing broken single-layer cloud; corresponding RRB image; and autocorrelation of RRB image.

  10. Supersymmetric inversion of effective-range expansions

    NASA Astrophysics Data System (ADS)

    Midya, Bikashkali; Evrard, Jérémie; Abramowicz, Sylvain; Ramírez Suárez, O. L.; Sparenberg, Jean-Marc

    2015-05-01

    A complete and consistent inversion technique is proposed to derive an accurate interaction potential from an effective-range function for a given partial wave in the neutral case. First, the effective-range function is Taylor or Padé expanded, which allows high precision fitting of the experimental scattering phase shifts with a minimal number of parameters on a large energy range. Second, the corresponding poles of the scattering matrix are extracted in the complex wave-number plane. Third, the interaction potential is constructed with supersymmetric transformations of the radial Schrödinger equation. As an illustration, the method is applied to the experimental phase shifts of the neutron-proton elastic scattering in the 1S0 and 1D2 channels on the [0 -350 ] MeV laboratory energy interval.

  11. Extended inertial range phenomenology of magnetohydrodynamic turbulence

    NASA Technical Reports Server (NTRS)

    Matthaeus, William H.; Zhou, YE

    1989-01-01

    A phenomenological treatment of the inertial range of isotropic statistically steady magnetohydrodynamic turbulence is presented, extending the theory of Kraichnan (1965). The role of Alfven wave propagation is treated on equal footing with nonlinear convection, leading to a simple generalization of the relations between the times characteristic of wave propagation, convection, energy transfer, and decay of triple correlations. The theory leads to a closed-form steady inertial range spectral law that reduces to the Kraichnan and Kolmogorov laws in appropriate limits. The Kraichnan constant is found to be related in a simple way to the Kolmogorov constant; for typical values of the latter constant, the former has values in the range 1.22-1.87. Estimates of the time scale associated with spectral transfer of energy also emerge from the new approach, generalizing previously presented 'golden rules' for relating the spectral transfer time scale to the Alfven and eddy-turnover time scales.

  12. Transverse ranges and neotectonics of southern California

    SciTech Connect

    Hill, M.L.

    1990-01-01

    The Transverse Ranges and the east-trending folds and reverse faults that elevate them began forming in mid-Pleistocene time by regional north-south crustal shortening. The adjacent Mojave Desert and Basin and Range provinces continue to respond to this regional strain by east-west crustal extension. Before {approximately}5 Ma the regional structure was characterized by conjugate northwest-trending right-slip faults (San Andreas set) and northeast-trending left-slip faults (Garlock set). Thereafter, the San Andreas set of faults became simple shears separating the North American and Pacific plates. With the mid-Pleistocene inception of the Transverse Ranges, the San Andreas fault deviated from its N40{degree} - 45{degree}W trend in short N75{degree}W-trending segments on the north and south sides of these mountains in response to the new, and local, strain system of upward crustal extension.

  13. Long-range correlations in nucleotide sequences

    NASA Astrophysics Data System (ADS)

    Peng, C.-K.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Sciortino, F.; Simons, M.; Stanley, H. E.

    1992-03-01

    DNA SEQUENCES have been analysed using models, such as an it-step Markov chain, that incorporate the possibility of short-range nucleotide correlations1. We propose here a method for studying the stochastic properties of nucleotide sequences by constructing a 1:1 map of the nucleotide sequence onto a walk, which we term a 'DNA walk'. We then use the mapping to provide a quantitative measure of the correlation between nucleotides over long distances along the DNA chain. Thus we uncover in the nucleotide sequence a remarkably long-range power law correlation that implies a new scale-invariant property of DNA. We find such long-range correlations in intron-containing genes and in nontranscribed regulatory DNA sequences, but not in complementary DNA sequences or intron-less genes.

  14. Extended range radiation dose-rate monitor

    DOEpatents

    Valentine, Kenneth H.

    1988-01-01

    An extended range dose-rate monitor is provided which utilizes the pulse pileup phenomenon that occurs in conventional counting systems to alter the dynamic response of the system to extend the dose-rate counting range. The current pulses from a solid-state detector generated by radiation events are amplified and shaped prior to applying the pulses to the input of a comparator. The comparator generates one logic pulse for each input pulse which exceeds the comparator reference threshold. These pulses are integrated and applied to a meter calibrated to indicate the measured dose-rate in response to the integrator output. A portion of the output signal from the integrator is fed back to vary the comparator reference threshold in proportion to the output count rate to extend the sensitive dynamic detection range by delaying the asymptotic approach of the integrator output toward full scale as measured by the meter.

  15. On-Orbit Range Set Applications

    NASA Astrophysics Data System (ADS)

    Holzinger, M.; Scheeres, D.

    2011-09-01

    History and methodology of ∆v range set computation is briefly reviewed, followed by a short summary of the ∆v optimal spacecraft servicing problem literature. Service vehicle placement is approached from a ∆v range set viewpoint, providing a framework under which the analysis becomes quite geometric and intuitive. The optimal servicing tour design problem is shown to be a specific instantiation of the metric- Traveling Salesman Problem (TSP), which in general is an NP-hard problem. The ∆v-TSP is argued to be quite similar to the Euclidean-TSP, for which approximate optimal solutions may be found in polynomial time. Applications of range sets are demonstrated using analytical and simulation results.

  16. Results of laser ranging collocations during 1983

    NASA Technical Reports Server (NTRS)

    Kolenkiewicz, R.

    1984-01-01

    The objective of laser ranging collocations is to compare the ability of two satellite laser ranging systems, located in the vicinity of one another, to measure the distance to an artificial Earth satellite in orbit over the sites. The similar measurement of this distance is essential before a new or modified laser system is deployed to worldwide locations in order to gather the data necessary to meet the scientific goals of the Crustal Dynamics Project. In order to be certain the laser systems are operating properly, they are periodically compared with each other. These comparisons or collocations are performed by locating the lasers side by side when they track the same satellite during the same time or pass. The data is then compared to make sure the lasers are giving essentially the same range results. Results of the three collocations performed during 1983 are given.

  17. Tropospheric range error parameters: Further studies

    NASA Technical Reports Server (NTRS)

    Hopfield, H. S.

    1972-01-01

    Improved parameters are presented for predicting the tropospheric effect on electromagnetic range measurements from surface meteorological data. Parameters are given for computing the dry component of the zenith radio range effect from surface pressure alone with an rms error of 1 to 2 mm, or the total range effect from the dry and wet components of the surface refractivity, N, and a two-part quartic profile model. The parameters were obtained from meteorological balloon data with improved procedures, including the conversion of the geopotential heights of the balloon data to actual or geometric heights before using the data. The revised values of the parameter k show more latitude variation than is accounted for by the variation of g. This excess variation of k indicates a small latitude variation in the mean molecular weight of air and yields information about the latitude-varying water vapor content of air.

  18. Dynamic range tuning of graphene nanoresonators

    NASA Astrophysics Data System (ADS)

    Parmar, Marsha M.; Gangavarapu, P. R. Yasasvi; Naik, A. K.

    2015-09-01

    From sensing perspective, smaller electromechanical devices, in general, are expected to be more responsive to the stimuli. This enhanced performance, however, is contingent upon the noise sources remaining unchanged and the onset of nonlinear behavior not being precipitated by miniaturization. In this paper, we study the effect of strain on the nonlinearities and dynamic range in graphene nanoresonators. The dynamic response and the onset of nonlinearity in these devices are sensitive both to the electrostatic field used to actuate the device and the strain. By tuning the strain of the device by two orders of magnitude, we observe an enhancement of 25 dB in the dynamic range leading to a mass resolution of 100 yoctogram. The increase in dynamic range in our devices is modeled as a combined effect of strain and partial cancellation of elastic and electrostatic nonlinearities.

  19. Seismicity of the Coso Range, California

    SciTech Connect

    Walter, A.W.; Weaver, C.S.

    1980-05-10

    A 16-station seismographic network, approximately 40 km north-south by 30 km east-west, was installed in the Coso Range, California, in September 1975 as part of a geological and geophysical assessment of the geothermal resource potential of range. During the first 2 years of network operations, 4216 local earthquakes (0.5< or =m< or =3.9) defined zones of seismicity that strike radially outward from a Pleistocene rhyolite field located near the center of the Coso Range. Most earthquakes were located in zones showing a general northwest trend across the range. Six earthquake swarms occurred within the area that includes the rhyolite field. Fault plane solutions show regional north-south compression: earthquakes located in northwest striking zones generally had right lateral strike slip focal mechanisms, those in northeast striking zones left lateral strike slip focal mechanisms, and those in north-south striking zones both normal and strike slip focal mechanisms. Earthquake depths showed little variation across the Coso Range; the depth distribution is similar to that of several carefully studied segments of the central San Andreas fault. The b value calculated for the entire range is 0.99 +- 0.08. The rhyolite field has a significantly higher b value of 1.26 +- 0.16; if only the shallow events (depth <5 km) are used in the calculation, the b value for this area becomes even higher, 1.34 +- 0.24. The higher b values were interpreted as reflecting the existence of short average fault lengths (<5 km) within the rhyolite field. The seismic data and other data suggest that the fault system lying between the rhyolite field and the adjacent Coso Basin is an important tectonic boundary. Present information is insufficient to determine the geothermal production capability of this fault system, but is does suggest that the system is a good target for further exploration.

  20. Study on short distance laser ranging system

    NASA Astrophysics Data System (ADS)

    Bao, Jianan; Li, Jicheng; Zhang, Cong

    2015-02-01

    Laser ranging technology is an industrial non contact measuring technology. With the rapidly development of electronics and optical technology, the measuring precision has been improved continuously. In this paper, a simple structure measuring system which based on laser triangulation measuring theory, was built. The system consist of single point laser and CMOS receiver, its measuring range is from 90mm to 110mm. In order to get a higher position accuracy of light spot, gauss cumulative method was used in this paper. For realize the precision system calibration, a linear calibration method was introduced. The experiment shows that the system get a measuring precision of 10um.

  1. Current Trends in Satellite Laser Ranging

    NASA Technical Reports Server (NTRS)

    Pearlman, M. R.; Appleby, G. M.; Kirchner, G.; McGarry, J.; Murphy, T.; Noll, C. E.; Pavlis, E. C.; Pierron, F.

    2010-01-01

    Satellite Laser Ranging (SLR) techniques are used to accurately measure the distance from ground stations to retroreflectors on satellites and the moon. SLR is one of the fundamental techniques that define the international Terrestrial Reference Frame (iTRF), which is the basis upon which we measure many aspects of global change over space, time, and evolving technology. It is one of the fundamental techniques that define at a level of precision of a few mm the origin and scale of the ITRF. Laser Ranging provides precision orbit determination and instrument calibration/validation for satellite-borne altimeters for the better understanding of sea level change, ocean dynamics, ice budget, and terrestrial topography. Laser ranging is also a tool to study the dynamics of the Moon and fundamental constants. Many of the GNSS satellites now carry retro-reflectors for improved orbit determination, harmonization of reference frames, and in-orbit co-location and system performance validation. The GNSS Constellations will be the means of making the reference frame available to worldwide users. Data and products from these measurements support key aspects of the GEOSS 10-Year implementation Plan adopted on February 16, 2005, The ITRF has been identified as a key contribution of the JAG to GEOSS and the ILRS makes a major contribution for its development since its foundation. The ILRS delivers weekly additional realizations that are accumulated sequentially to extend the ITRF and the Earth Orientation Parameter (EOP) series with a daily resolution. Additional products are currently under development such as precise orbits of satellites, EOP with daily availability, low-degree gravitational harmonics for studies of Earth dynamics and kinematics, etc. SLR technology continues to evolve toward the next generation laser ranging systems as programmatic requirements become more stringent. Ranging accuracy is improving as higher repetition rate, narrower pulse lasers and faster

  2. Safety assessment of outdoor live fire range

    SciTech Connect

    1989-05-01

    The following Safety Assessment (SA) pertains to the outdoor live fire range facility (LFR). The purpose of this facility is to supplement the indoor LFR. In particular it provides capacity for exercises that would be inappropriate on the indoor range. This SA examines the risks that are attendant to the training on the outdoor LFR. The outdoor LFR used by EG&G Mound is privately owned. It is identified as the Miami Valley Shooting Grounds. Mondays are leased for the exclusive use of EG&G Mound.

  3. Wide-range radiation dose monitor

    DOEpatents

    Kopp, Manfred K.

    1986-01-01

    A radiation dose-rate monitor is provided which operates in a conventional linear mode for radiation in the 0 to 0.5 R/h range and utilizes a nonlinear mode of operation for sensing radiation from 0.5 R/h to over 500 R/h. The nonlinear mode is achieved by a feedback circuit which adjusts the high voltage bias of the proportional counter, and hence its gas gain, in accordance with the amount of radiation being monitored. This allows compression of readout onto a single scale over the range of 0 to greater than 500 R/h without scale switching operations.

  4. Wide-range radiation dose monitor

    DOEpatents

    Kopp, M.K.

    1984-09-20

    A radiation dose-rate monitor is provided which operates in a conventional linear mode for radiation in the 0 to 0.5 R/h range and utilizes a nonlinear mode of operation for sensing radiation from 0.5 R/h to over 500 R/h. The nonlinear mode is achieved by a feedback circuit which adjusts the high voltage bias of the proportional counter, and hence its gas gain, in accordance with the amount of radiation being monitored. This allows compression of readout onto a single scale over the range of 0 to greater than 500 R/h without scale switching operations.

  5. Atmospheric refraction errors in laser ranging systems

    NASA Technical Reports Server (NTRS)

    Gardner, C. S.; Rowlett, J. R.

    1976-01-01

    The effects of horizontal refractivity gradients on the accuracy of laser ranging systems were investigated by ray tracing through three dimensional refractivity profiles. The profiles were generated by performing a multiple regression on measurements from seven or eight radiosondes, using a refractivity model which provided for both linear and quadratic variations in the horizontal direction. The range correction due to horizontal gradients was found to be an approximately sinusoidal function of azimuth having a minimum near 0 deg azimuth and a maximum near 180 deg azimuth. The peak to peak variation was approximately 5 centimeters at 10 deg elevation and decreased to less than 1 millimeter at 80 deg elevation.

  6. Short-Range Structure of Nuclei

    SciTech Connect

    Higinbotham, Douglas W.

    2008-10-13

    The nucleons in a nucleus can form short-range correlated pairs. A recent Jefferson Lab electron scattering experiment, where a proton was knocked-out of the nucleus with high momentum transfer and high missing momentum, has shown that in {sup 12}C the neutron-proton pairs are nearly twenty times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs has been shown to be due to the short-range tensor part of the nucleon-nucleon interaction.

  7. Photon assisted long-range tunneling

    SciTech Connect

    Gallego-Marcos, Fernando; Sánchez, Rafael; Platero, Gloria

    2015-03-21

    We analyze long-range transport through an ac driven triple quantum dot with a single electron. Resonant transitions between separated and detuned dots are mediated by the exchange of n photons with the time-dependent field. An effective model is proposed in terms of second order (cotunneling) processes which dominate the long-range transport between the edge quantum dots. The ac field renormalizes the inter dot hopping, modifying the level hybridization. It results in a non-trivial behavior of the current with the frequency and amplitude of the external ac field.

  8. Long-range imaging ladar flight test

    NASA Astrophysics Data System (ADS)

    Brandt, James; Steiner, Todd D.; Mandeville, William J.; Dinndorf, Kenneth M.; Krasutsky, Nick J.; Minor, John L.

    1995-06-01

    Wright Laboratory and Loral Vought Systems (LVS) have been involved for the last nine years in the research and development of high power diode pumped solid state lasers for medium to long range laser radar (LADAR) seekers for tactical air-to-ground munitions. LVS provided the lead in three key LADAR programs at Wright Lab; the Submunition Guidance Program (Subguide), the Low Cost Anti-Armor Submunition Program (LOCAAS) and the Diode Laser and Detector Array Development Program (3-D). This paper discusses recent advances through the 3-D program that provide the opportunity to obtain three dimensional laser radar imagery in captive flight at a range of 5 km.

  9. Range Filtering For Navigation By Satellite

    NASA Technical Reports Server (NTRS)

    Paielli, Russell

    1989-01-01

    Less processing and storage of data needed. Mathematical basis developed for Kalman filtering of sequential measurements of range from single-channel receiver in Global Positioning System (GPS) to each of several navigation satellites. Range filtering involves separate applications of kinematic Kalman tracking filter to measurements of signal from each satellite in use. State vector consists of pseudorange and time derivatives. Main advantages: simplification of tuning and decreases in required amounts of storage and processing of data for navigation in ships, airplanes, and ground vehicles.

  10. Inertial Range Dynamics in Boussinesq Turbulence

    NASA Technical Reports Server (NTRS)

    Rubinstein, Robert

    1996-01-01

    L'vov and Falkovich have shown that the dimensionally possible inertial range scaling laws for Boussinesq turbulence, Kolmogorov and Bolgiano scaling, describe steady states with constant flux of kinetic energy and of entropy respectively. These scaling laws are treated as similarity solutions of the direct interaction approximation for Boussinesq turbulence. The Kolmogorov scaling solution corresponds to a weak perturbation by gravity of a state in which the temperature is a passive scalar but in which a source of temperature fluctuations exists. Using standard inertial range balances, the renormalized viscosity and conductivity, turbulent Prandtl number, and spectral scaling law constants are computed for Bolgiano scaling.

  11. Laser Doppler And Range Systems For Spacecraft

    NASA Technical Reports Server (NTRS)

    Kinman, P. W.; Gagliardi, R. M.

    1990-01-01

    Report discusses two types of proposed laser systems containing active transponders measuring distance (range) and line-of-sight velocity (via Doppler effect) between deep space vehicle and earth-orbiting satellite. Laser system offers diffraction advantage over microwave system. Delivers comparable power to distant receiver while using smaller transmitting and receiving antennas and less-powerful transmitter. Less subject to phase scintillations caused by passage through such inhomogeneous media as solar corona. One type of system called "incoherent" because range and Doppler measurements do not require coherence with laser carrier signals. Other type of system called "coherent" because successful operation requires coherent tracking of laser signals.

  12. GOPEX at the Starfire Optical Range

    NASA Technical Reports Server (NTRS)

    Fugate, R. Q.

    1993-01-01

    The Starfire Optical Range successfully conducted laser upink experiments to the Galileo spacecraft during the early morning hours of December 9, 10, 11, and 12, 1992, when the spacecraft was at ranges between 700,000 and 3 million km from Earth. Analysts at JPL have reported as many as 79 pulse detections by the spacecraft. The best weather conditions occurred on the second night when 37 pulses were detected with as many as five on one frame. Signal levels at the spacecraft generally agree with predictions.

  13. Forest and Range Inventory and Mapping

    NASA Technical Reports Server (NTRS)

    Aldrich, R. C.

    1971-01-01

    The state of the art in remote sensing for forest and range inventories and mapping has been discussed. There remains a long way to go before some of these techniques can be used on an operational basis. By the time that the Earth Resources Technology Satellite and Skylab space missions are flown, it should be possible to tell what kind and what quality of information can be extracted from remote sensors and how it can be used for surveys of forest and range resources.

  14. Frequency skewed optical pulses for range detection

    NASA Astrophysics Data System (ADS)

    Ozharar, Sarper; Gee, Sangyoun; Quinlan, Franklyn; Delfyett, Peter J., Jr.

    2007-04-01

    Frequency skewed optical pulses are generated via both a composite cavity structure in a fiberized semiconductor optical amplifier ring laser and a frequency skew loop outside the laser cavity. The composite cavity technique is similar to rational harmonic mode-locking, however it is based on cavity detuning rather than frequency detuning. These frequency skewed pulses are ideal for range detection applications since their interference results in a range dependent RF signal. The intracavity frequency skewed pulse train showed superior performance in both stability and signal quality.

  15. Lunar laser ranging data identification and management

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Activity under the subject grant during the first half of fiscal year 1979 at the University of Texas at Austin is reported. Raw lunar laser ranging data submitted by McDonald Observatory, Fort Davis, Texas and by the Australian Division of National Mapping at Orroral Valley, Australia were processed. This processing includes the filtering of signal events from noise photons, normal point formation, data archive management, and data distribution. System-wide program maintenance and up-grade carried out wherever and whenever necessary. Lunar laser ranging data is being transmitted from Austin to Paris for the extraction of earth rotation information during the EROLD campaign.

  16. Photon assisted long-range tunneling

    NASA Astrophysics Data System (ADS)

    Gallego-Marcos, Fernando; Sánchez, Rafael; Platero, Gloria

    2015-03-01

    We analyze long-range transport through an ac driven triple quantum dot with a single electron. Resonant transitions between separated and detuned dots are mediated by the exchange of n photons with the time-dependent field. An effective model is proposed in terms of second order (cotunneling) processes which dominate the long-range transport between the edge quantum dots. The ac field renormalizes the inter dot hopping, modifying the level hybridization. It results in a non-trivial behavior of the current with the frequency and amplitude of the external ac field.

  17. Exploiting range imagery: techniques and applications

    NASA Astrophysics Data System (ADS)

    Armbruster, Walter

    2009-07-01

    Practically no applications exist for which automatic processing of 2D intensity imagery can equal human visual perception. This is not the case for range imagery. The paper gives examples of 3D laser radar applications, for which automatic data processing can exceed human visual cognition capabilities and describes basic processing techniques for attaining these results. The examples are drawn from the fields of helicopter obstacle avoidance, object detection in surveillance applications, object recognition at high range, multi-object-tracking, and object re-identification in range image sequences. Processing times and recognition performances are summarized. The techniques used exploit the bijective continuity of the imaging process as well as its independence of object reflectivity, emissivity and illumination. This allows precise formulations of the probability distributions involved in figure-ground segmentation, feature-based object classification and model based object recognition. The probabilistic approach guarantees optimal solutions for single images and enables Bayesian learning in range image sequences. Finally, due to recent results in 3D-surface completion, no prior model libraries are required for recognizing and re-identifying objects of quite general object categories, opening the way to unsupervised learning and fully autonomous cognitive systems.

  18. Transponder System for High-Frequency Ranging

    NASA Technical Reports Server (NTRS)

    Lichtenberg, C. L.; Shores, P. W.; Kobayashi, H. S.

    1986-01-01

    Transponder system uses phase difference between transmitted and reflected high-frequency radio waves to measure distance to target. To suppress spurious measurements of reflections from objects near target at transmitted frequency and its harmonics, transponder at target generates return signal at half transmitted frequency. System useful in such applications as surveying, docking of ships, and short-range navigation.

  19. SALMONELLA ON FREE-RANGE CHICKENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many consumers assume that broiler chickens grown under traditional commercial conditions will have more salmonella than free-range chickens which are usually less crowded and have access to outside spaces during grow-out. However, because of the lack of published information about the microbiologi...

  20. Least limiting water range of soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The least limiting water range (LLWR) has been developed as an index of the soil structural quality. The LLWR was defined as the region bounded by the upper and lower soil water content over which water, oxygen, and mechanical resistance become major limitations for root growth. Thus, it combines th...

  1. Long-Range Plan, 1978-83.

    ERIC Educational Resources Information Center

    Jonas, Stephen

    This nine-part, long-range plan discusses the internal and external factors that will affect Lorain County Community College's (LCCC's) development from 1978 to 1983 and presents a forecast of LCCC's future needs. Part I traces the history of LCCC, provides a conceptual framework for college planning, and discusses the plan development process…

  2. Range gating experiments through a scattering media

    SciTech Connect

    Payton, J.; Cverna, F.; Gallegos, R.; McDonald, T.; Numkena, D.; Obst, A.; Pena-Abeyta, C.; Yates, G.

    1998-12-31

    This paper discusses range-gated imaging experiments performed recently at Redstone Arsenal in Huntsville, Alabama. Range gating is an imaging technique that uses a pulsed laser and gated camera to image objects at specific ranges. The technique can be used for imaging through scattering media such as dense smoke or fog. Range gating uses the fact that light travels at 3 x 10{sup 8} m/s. Knowing the speed of light the authors can calculate the time it will take the laser light to travel a known distance, then gate open a Micro Channel Plate Image Intensifier (MCPII) at the time the reflected light returns from the target. In the Redstone experiment the gate width on the MCPII was set to equal the laser pulse width ({approximately} 8 ns) for the highest signal to noise ratio. The gate allows the light reflected form the target and a small portion of the light reflected from the smoke in the vicinity of the target to be imaged. They obtained good results in light and medium smoke but the laser they were used did not have sufficient intensity to penetrate the thickest smoke. They did not diverge the laser beam to cover the entire target in order to maintain a high flux that would achieve better penetration through the smoke. They were able to image an Armored Personnel Carrier (APC) through light and medium smoke but they were not able to image the APC through heavy smoke. The experiment and results are presented.

  3. Controlling a wide range of flow rates

    NASA Technical Reports Server (NTRS)

    Perkins, G. S.

    1979-01-01

    Servo-operated valve and two flowmeters allow accurate control over 1,900:1 flow-rate range. It was developed as part of laboratory instrument for measuring properties of confined fluids under conditions analogous to those encountered in deep drilling operations.

  4. Wide temperature range seal for demountable joints

    DOEpatents

    Sixsmith, Herbert; Valenzuela, Javier A.; Nutt, William E.

    1991-07-23

    The present invention is directed to a seal for demountable joints operating over a wide temperature range down to liquid helium temperatures. The seal has anti-extrusion guards which prevent extrusion of the soft ductile sealant material, which may be indium or an alloy thereof.

  5. Global Test Range: Toward Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Mace, Thomas H.; Freudinger, Larry; DelFrate John H.

    2008-01-01

    This viewgraph presentation reviews the planned global sensor network that will monitor the Earth's climate, and resources using airborne sensor systems. The vision is an intelligent, affordable Earth Observation System. Global Test Range is a lab developing trustworthy services for airborne instruments - a specialized Internet Service Provider. There is discussion of several current and planned missions.

  6. Discussion of long-range weather prediction

    SciTech Connect

    Canavan, G.H.

    1998-09-10

    A group of scientists at Los Alamos have held a series of discussions of the issues in and prospects for improvements in Long-range Weather Predictions Enabled by Proving of the Atmosphere at High Space-Time Resolution. The group contained the requisite skills for a full evaluation, although this report presents only an informal discussion of the main technical issues. The group discussed all aspects of the proposal, which are grouped below into the headings: (1) predictability; (2) sensors and satellites, (3) DIAL and atmospheric sensing; (4) localized transponders; and (5) summary and integration. Briefly, the group agreed that the relative paucity of observations of the state of the atmosphere severely inhibits the accuracy of weather forecasts, and any program that leads to a more dense and uniform observational network is welcome. As shown in Long-range Weather more dense and uniform observational network is welcome. As shown in Long-range Weather Predictions, the pay-back of accurate long-range forecasts should more than justify the expenditure associated with improved observations and forecast models required. The essential step is to show that the needed technologies are available for field test and space qualification.

  7. Compact range for variable-zone measurements

    DOEpatents

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-01-01

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  8. Compact range for variable-zone measurements

    DOEpatents

    Burnside, W.D.; Rudduck, R.C.; Yu, J.S.

    1987-02-27

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector. 2 figs.

  9. Predicting individual fusional range from optometric data

    NASA Astrophysics Data System (ADS)

    Endrikhovski, Serguei; Jin, Elaine; Miller, Michael E.; Ford, Robert W.

    2005-03-01

    A model was developed to predict the range of disparities that can be fused by an individual user from optometric measurements. This model uses parameters, such as dissociated phoria and fusional reserves, to calculate an individual user"s fusional range (i.e., the disparities that can be fused on stereoscopic displays) when the user views a stereoscopic stimulus from various distances. This model is validated by comparing its output with data from a study in which the individual fusional range of a group of users was quantified while they viewed a stereoscopic display from distances of 0.5, 1.0, and 2.0 meters. Overall, the model provides good data predictions for the majority of the subjects and can be generalized for other viewing conditions. The model may, therefore, be used within a customized stereoscopic system, which would render stereoscopic information in a way that accounts for the individual differences in fusional range. Because the comfort of an individual user also depends on the user"s ability to fuse stereo images, such a system may, consequently, improve the comfort level and viewing experience for people with different stereoscopic fusional capabilities.

  10. Look Ahead: Long-Range Learning Plans

    ERIC Educational Resources Information Center

    Weinstein, Margery

    2010-01-01

    Faced with an unsteady economy and fluctuating learning needs, planning a learning strategy designed to last longer than the next six months can be a tall order. But a long-range learning plan can provide a road map for success. In this article, four companies (KPMG LLP, CarMax, DPR Construction, and EMC Corp.) describe their learning plans, and…

  11. The ideal Kolmogorov inertial range and constant

    NASA Technical Reports Server (NTRS)

    Zhou, YE

    1993-01-01

    The energy transfer statistics measured in numerically simulated flows are found to be nearly self-similar for wavenumbers in the inertial range. Using the measured self-similar form, an 'ideal' energy transfer function and the corresponding energy flux rate were deduced. From this flux rate, the Kolmogorov constant was calculated to be 1.5, in excellent agreement with experiments.

  12. Wide temperature range seal for demountable joints

    DOEpatents

    Sixsmith, H.; Valenzuela, J.A.; Nutt, W.E.

    1991-07-23

    The present invention is directed to a seal for demountable joints operating over a wide temperature range down to liquid helium temperatures. The seal has anti-extrusion guards which prevent extrusion of the soft ductile sealant material, which may be indium or an alloy thereof. 6 figures.

  13. Antenna induced range smearing in MST radars

    NASA Technical Reports Server (NTRS)

    Watkins, B. J.; Johnston, P. E.

    1984-01-01

    There is considerable interest in developing stratosphere troposphere (ST) and mesosphere stratosphere troposphere (MST) radars for higher resolution to study small-scale turbulent structures and waves. At present most ST and MST radars have resolutions of 150 meters or larger, and are not able to distinguish the thin (40 - 100 m) turbulent layers that are known to occur in the troposphere and stratosphere, and possibly in the mesosphere. However the antenna beam width and sidelobe level become important considerations for radars with superior height resolution. The objective of this paper is to point out that for radars with range resolutions of about 150 meters or less, there may be significant range smearing of the signals from mesospheric altitudes due to the finite beam width of the radar antenna. At both stratospheric and mesospheric heights the antenna sidelobe level for lear equally spaced phased arrays may also produce range aliased signals. To illustrate this effect the range smearing functions for two vertically directed antennas have been calculated, (1) an array of 32 coaxial-collinear strings each with 48 elements that simulates the vertical beam of the Poker Flat, Glaska, MST radar; and (2) a similar, but smaller, array of 16 coaxial-collinear strings each with 24 elements.

  14. Constrained optimum trajectories with specified range

    NASA Technical Reports Server (NTRS)

    Erzberger, H.; Lee, H.

    1980-01-01

    The characteristics of optimum fixed-range trajectories whose structure is constrained to climb, steady cruise, and descent segments are derived by application of optimal control theory. The performance function consists of the sum of fuel and time costs, referred to as direct operating costs (DOC). The state variable is range-to-go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (500 n. mi. and less) a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur. The performance difference between free thrust and constrained thrust trajectories has been determined in computer calculations for an example transport aircraft.

  15. Compact range for variable-zone measurements

    DOEpatents

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-08-02

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  16. Nonperturbative short-range dynamics in TMDs

    SciTech Connect

    Weiss, Christian

    2013-05-01

    This presentation covers: deep inelastic processes and transverse momentum distributions; chiral symmetry breaking, including the physical picture, the dynamical model, and parton distributions; partonic structures, including transverse momentum distributions, coordinate space correlator, and short range correlations; and measurements of semi-inclusive deep inelastic scattering, correlations, and multi-parton processes in pp interactions.

  17. Range Imaging for Underwater Vision Enhancement

    SciTech Connect

    Rish, J.W.; Blume, B.; Nellums, B.; Sackos, J.; Foster, J.; Wood, J.L.

    1999-04-19

    This paper presents results from a series of preliminary tests to evaluate a scannerless range-imaging device as a potential sensory enhancement tool for divers and as a potential identification sensor for deployment on small unmanned underwater vehicles. The device, developed by Sandia National Laboratories, forms an image on the basis of point-to-point range to the target rather than an intensity map. The range image is constructed through a classical continuous wave phase detection technique in which the light source is amplitude modulated at radio frequencies. The receiver incorporates a gain-modulated image intensifier, and range information is calculated on the basis of the phase difference between the transmitted and reflected signal. The initial feasibility test at the Coastal Systems Station showed the device to be effective at imaging low-contrast underwater targets such as concertina wire. It also demonstrated success at imaging a 21-inch sphere at a depth of 10 feet in the water column through a wavy air-water interface.

  18. Resources and Long-Range Forecasts

    ERIC Educational Resources Information Center

    Smith, Waldo E.

    1973-01-01

    The author argues that forecasts of quick depletion of resources in the environment as a result of overpopulation and increased usage may not be free from error. Ignorance still exists in understanding the recovery mechanisms of nature. Long-range forecasts are likely to be wrong in such situations. (PS)

  19. TEMPERATURE AND RANGE EXTENSION BY PERKINSUS MARINUS

    EPA Science Inventory

    Between 1990 and 1992, Dermo disease of oysters, caused by Perkinsus marinus, experienced a 500-km northward range extension and is now established as far north as Massachusetts. Climate warming during the 1980s and early 1990s, combined with historical introductions of infected ...

  20. Signal phase switches offer greater dynamic range

    NASA Technical Reports Server (NTRS)

    Crow, R. B.

    1970-01-01

    Circuit, placed in the signal path of a closed-loop receiver to modulate telemetered data in the 10-MHz spectrum, improves signal-to-noise ratio by 3 db in a communication receiver. The switch enables bandwidth reduction which reduces noise overload on the following stages, giving the system greater dynamic range.