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Sample records for autonomous star tracker

  1. On-Orbit Performance of Autonomous Star Trackers

    NASA Technical Reports Server (NTRS)

    Airapetian, V.; Sedlak, J.; Hashmall, J.

    2001-01-01

    This paper presents the results of a performance study of the autonomous star trackers (ASTs) on the IMAGE and the EO-1 spacecraft. IMAGE is a spinning spacecraft without gyros or redundant precision attitude sensors, so the statistical properties of the AST are estimated simply by comparing the output observed quaternions with a rigid rotator model with constant angular momentum. The initial conditions are determined by a least-squares fit to minimize the AST residuals. An additional fit is used to remove the remaining systematic error and to obtain the inherent sensor noise. Gyro rate data are available for the EO-1 mission, so the AST noise statistics are obtained from the residuals after solving for an epoch attitude and gyro bias also using a least-squares method.

  2. Operational Experience with Autonomous Star Trackers on ESA Interplanetary Spacecraft

    NASA Technical Reports Server (NTRS)

    Lauer, Mathias; Jauregui, Libe; Kielbassa, Sabine

    2007-01-01

    Mars Express (MEX), Rosetta and Venus Express (VEX) are ESA interplanetary spacecrafts (S/C) launched in June 2003, March 2004 and November 2005, respectively. Mars Express was injected into Mars orbit end of 2003 with routine operations starting in spring 2004. Rosetta is since launch on its way to rendezvous comet Churyumov-Gerasimenko in 2014. It has completed several test and commissioning activities and is performing several planetary swingbys (Earth in spring 2005, Mars in spring 2007, Earth in autumn 2007 and again two years later). Venus Express has also started routine operations since the completion of the Venus orbit insertion maneuver sequence beginning of May 2006. All three S/C are three axes stabilized with a similar attitude and orbit control system (AOCS). The attitude is estimated on board using star and rate sensors and controlled using four reaction wheels. A bipropellant reaction control system with 10N thrusters serves for wheel off loadings and attitude control in safe mode. Mars Express and Venus Express have an additional 400N engine for the planetary orbit insertion. Nominal Earth communication is accomplished through a high gain antenna. All three S/C are equipped with a redundant set of autonomous star trackers (STR) which are based on almost the same hardware. The STR software is especially adapted for the respective mission. This paper addresses several topics related to the experience gained with the STR operations on board the three S/C so far.

  3. Vidicon star tracker.

    PubMed

    Schuck, W H

    1966-04-01

    In many applications of star trackers, extremely short acquisition times, as well as accuracy and sensitivity, are required. Tracking systems employing the vidicon as a radiation sensor have been shown to provide the necessary speed of acquisition for such applications. This paper discusses the various theoretical and practical considerations involved in using the vidicon as a sensor in a star tracking system. A typical system configuration including telescope, sensor, and processing electronics is presented. The various optical and sensor parametric relationships required in the design of a vidicon star tracker are fully discussed and analyzed. PMID:20048884

  4. Intelligent star tracker

    NASA Astrophysics Data System (ADS)

    Clark, Natalie

    2001-11-01

    Current state-of-the-art commercial star sensors typically weigh 15 pounds, attain 5 to 10 arc-second accuracy, and use roughly 10 watts of power. Unfortunately, the current state-of-the-art commercial star sensors do not meet many of NASA's next-generation spacecraft and instrument needs. Nor do they satisfy Air Force's needs for micro/nano-satellite systems. In an effort to satisfy micro/nano satellite mission needs the Air Force Research Laboratory is developing an intelligent star Tracker, called IntelliStar, which incorporates several novel technologies including Silicon carbide optical housing, MEMs based adaptive optic technologies, smart active pixels, and algebraic coding theory. The design considerations associated with the development of the IntelliStar system are presented along with experimental results which characterize each technologies contribution to overall system performance. In addition to being light weight, the IntelliStar System offers advantages in speed, size, power consumption, and radiation tolerance.

  5. STAR heavy flavor tracker

    NASA Astrophysics Data System (ADS)

    Qiu, Hao

    2014-11-01

    Hadrons containing heavy quarks are a clean probe of the early dynamic evolution of the dense and hot medium created in high-energy nuclear collisions. To explore heavy quark production at RHIC, the Heavy Flavor Tracker (HFT) for the STAR experiment was built and installed in time for RHIC Run 14. The HFT consists of four layers of silicon detectors. The two outermost layers are silicon strip detectors and the two innermost layers are made from state-of-the-art ultra-thin CMOS Monolithic Active Pixel Sensors (MAPS). This is the first application of a CMOS MAPS detector in a collider experiment. The use of thin pixel sensors plus the use of carbon fiber supporting material limits the material budget to be only 0.4% radiation length per pixel detector layer, enabling the reconstruction of low pT heavy flavor hadrons. The status and performance of the HFT in the RHIC 200 GeV Au + Au run in 2014 are reported. Very good detector efficiency, hit residuals and track resolution (DCAs) were observed in the cosmic ray data and in the Au + Au data.

  6. Space Shuttle Star Tracker Challenges

    NASA Technical Reports Server (NTRS)

    Herrera, Linda M.

    2010-01-01

    The space shuttle fleet of avionics was originally designed in the 1970's. Many of the subsystems have been upgraded and replaced, however some original hardware continues to fly. Not only fly, but has proven to be the best design available to perform its designated task. The shuttle star tracker system is currently flying as a mixture of old and new designs, each with a unique purpose to fill for the mission. Orbiter missions have tackled many varied missions in space over the years. As the orbiters began flying to the International Space Station (ISS), new challenges were discovered and overcome as new trusses and modules were added. For the star tracker subsystem, the growing ISS posed an unusual problem, bright light. With two star trackers on board, the 1970's vintage image dissector tube (IDT) star trackers track the ISS, while the new solid state design is used for dim star tracking. This presentation focuses on the challenges and solutions used to ensure star trackers can complete the shuttle missions successfully. Topics include KSC team and industry partner methods used to correct pressurized case failures and track system performance.

  7. Optical filtering for star trackers

    NASA Technical Reports Server (NTRS)

    Wilson, R. E.

    1973-01-01

    The optimization of optical filtering was investigated for tracking faint stars, down to the fifth magnitude. The effective wavelength and bandwidth for tracking pre-selected guide stars are discussed along with the results of an all-electronic tracker with a star tracking photomultiplier, which was tested with a simulated second magnitude star. Tables which give the sum of zodiacal light and galactic background light over the entire sky for intervals of five degrees in declination, and twenty minutes in right ascension are included.

  8. Performance of the Microwave Anisotropy Probe AST-201 Star Trackers

    NASA Technical Reports Server (NTRS)

    Ward, David K.; vanBezooijen, Roelof; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe (MAP) was launched to create a full-sky map of the cosmic microwave background. MAP incorporates two modified Lockheed Martin AST-201 (Autonomous Star Tracker) star trackers. The AST-201 employs an eight element radiation hardened lens assembly which is used to focus an image on a charge coupled device (CCD). The CCD image is then processed by a star identification algorithm which outputs a three-axis attitude. A CCD-shift algorithm called Time Delayed Integration (TDI) was also included in each star tracker. In order to provide some radiation effect filtering during MAP's three to five phasing loop passes through the Van Allen radiation belts, a simple pixel filtering scheme was implemented, rather than using a more complex, but more robust windowing algorithm. The trackers also include a fiber optic data interface. This paper details the ground testing that was accomplished on the MAP trackers.

  9. Star-Tracker Computer Program

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas

    1987-01-01

    Image-analyzing pointing systems aimed to high precision. Star-tracker program, STRACKER, developed to solve algorithm-design problems for area-array tracking and pointing systems operating at accuracies of 0.001 to 0.01 picture element. Includes auxiliary programs for reformatting point-spread data from commercial ACCOSV lens-design program. Other optical-analysis program data reformatted by use of utility routines included in package. Written in FORTRAN 77.

  10. Star tracker for the Apollo telescope mount

    NASA Technical Reports Server (NTRS)

    Lee, C. E.

    1971-01-01

    The star tracker for the Apollo Telescope Mount (ATM) has been designed specifically to meet the requirements of the Skylab vehicle and mission. The functions of the star tracker are presented, as well as descriptions of the optical-mechanical assembly (OMA) and the star tracker electronics (STE). Also included are the electronic and mechanical specifications, interface and operational requirements, support equipment and test requirements, and occultation information. Laboratory functional tests, environmental qualification tests, and life tests have provided a high confidence factor in the performance of the star tracker in the laboratory and on the Skylab mission.

  11. Flight experience of 329K star tracker

    NASA Astrophysics Data System (ADS)

    Kruzhilov, Ivan S.; Kuniaev, Vladimir V.; Fedoseev, Victor I.; Titov, Gennadiy P.; Shevlyakov, Oleg V.; Latyncev, Sergey V.

    2013-10-01

    The paper is devoted to the results of the star tracker 329K flight tests on board of the satellites Luch-5A and Luch-5B launched into geostationary orbit in December 2011 and November 2012 respectively. Emphasis is placed on accuracy and photometric characteristics of the star tracker 329K.

  12. The STAR Heavy Flavor Tracker

    NASA Astrophysics Data System (ADS)

    Videbaek, Flemming; STAR Collaboration

    2013-10-01

    The Heavy Flavor Tracker (HFT) is an on-going upgrade for the STAR detector at RHIC that aim to study heavy quark production. In relativistic heavy-ion collisions at RHIC, heavy quarks are primarily created from initial hard scatterings. Since their large masses are not easily affected by the strong interaction with QCD medium they may carry information from the system at early stage. The interaction between heavy quarks and the medium is sensitive to the medium dynamics; therefore heavy quarks are suggested as an ideal probe to quantify the properties of the strongly interacting QCD matter. The HFT detectors will study this via the topological reconstruction of open charm hadrons. The HFT that consists of a thin two layer inner Pixel vertex detector, and two outer concentric layers of silicon, the Silicon Strip Detector, and the Intermediate Silicon Tracker. We will show how this detector system can assess heavy flavor physics with great precision. An overview of the HFT that will be completed for the upcoming RHIC run-14, its expected performance, and current status will be presented. Supported by the Division of Nuclear Physics of the Office of Science of the U.S. Department of Energy.

  13. A Heavy Flavor Tracker for STAR

    SciTech Connect

    Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H.; Tai, A.; Kushpil, V.; Sumbera, M.; Colledani, C.; Dulinski, W.; Himmi,A.; Hu, C.; Shabetai, A.; Szelezniak, M.; Valin, I.; Winter, M.; Miller,M.; Surrow, B.; Van Nieuwenhuizen G.; Bieser, F.; Gareus, R.; Greiner,L.; Lesser, F.; Matis, H.S.; Oldenburg, M.; Ritter, H.G.; Pierpoint, L.; Retiere, F.; Rose, A.; Schweda, K.; Sichtermann, E.; Thomas, J.H.; Wieman, H.; Yamamoto, E.; Kotov, I.

    2005-03-14

    We propose to construct a Heavy Flavor Tracker (HFT) for theSTAR experiment at RHIC. The HFT will bring new physics capabilities toSTAR and it will significantly enhance the physics capabilities of theSTAR detector at central rapidities. The HFT will ensure that STAR willbe able to take heavy flavor data at all luminosities attainablethroughout the proposed RHIC II era.

  14. A Heavy Flavor Tracker for STAR

    SciTech Connect

    Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H.; Tai, A.; Kushpil, V.; Sumbera, M.; Colledani, C.; Dulinski, W.; Himmi,A.; Hu, C.; Shabetai, A.; Szelezniak, M.; Valin, I.; Winter, M.; Surrow,B.; Van Nieuwenhuizen, G.; Bieser, F.; Gareus, R.; Greiner, L.; Lesser,F.; Matis, H.S.; Oldenburg, M.; Ritter, H.G.; Pierpoint, L.; Retiere, F.; Rose, A.; Schweda, K.; Sichtermann, E.; Thomas, J.H.; Wieman, H.; Yamamoto, E.; Kotov, I.

    2005-03-14

    We propose to construct a Heavy Flavor Tracker (HFT) for the STAR experiment at RHIC. The HFT will bring new physics capabilities to STAR and it will significantly enhance the physics capabilities of the STAR detector at central rapidities. The HFT will ensure that STAR will be able to take heavy flavor data at all luminosities attainable throughout the proposed RHIC II era.

  15. Opportunity Science Using the Juno Magnetometer Investigation Star Trackers

    NASA Astrophysics Data System (ADS)

    Joergensen, J. L.; Connerney, J. E.; Bang, A. M.; Denver, T.; Oliversen, R. J.; Benn, M.; Lawton, P.

    2013-12-01

    The magnetometer experiment onboard Juno is equipped with four non-magnetic star tracker camera heads, two of which reside on each of the magnetometer sensor optical benches. These are located 10 and 12 m from the spacecraft body at the end of one of the three solar panel wings. The star tracker, collectively referred to as the Advanced Stellar Compass (ASC), provides high accuracy attitude information for the magnetometer sensors throughout science operations. The star tracker camera heads are pointed +/- 13 deg off the spin vector, in the anti-sun direction, imaging a 13 x 20 deg field of view every ¼ second as Juno rotates at 1 or 2 rpm. The ASC is a fully autonomous star tracker, producing a time series of attitude quaternions for each camera head, utilizing a suite of internal support functions. These include imaging capabilities, autonomous object tracking, automatic dark-sky monitoring, and related capabilities; these internal functions may be accessed via telecommand. During Juno's cruise phase, this capability can be tapped to provide unique science and engineering data available along the Juno trajectory. We present a few examples of the JUNO ASC opportunity science here. As the Juno spacecraft approached the Earth-Moon system for the close encounter with the Earth on October 9, 2013, one of the ASC camera heads obtained imagery of the Earth-Moon system while the other three remained in full science (attitude determination) operation. This enabled the first movie of the Earth and Moon obtained by a spacecraft flying past the Earth in gravity assist. We also use the many artificial satellites in orbit about the Earth as calibration targets for the autonomous asteroid detection system inherent to the ASC autonomous star tracker. We shall also profile the zodiacal dust disk, using the interstellar image data, and present the outlook for small asteroid body detection and distribution being performed during Juno's passage from Earth flyby to Jovian orbit

  16. A microprocessor-controlled CCD star tracker

    NASA Technical Reports Server (NTRS)

    Salomon, P. M.; Goss, W. C.

    1976-01-01

    The STELLAR (Star Tracker for Economical Long Life Attitude Reference) utilizes an image sensing Charge-Coupled Device (CCD) operating under microprocessor control. This approach results in a new type of high-accuracy star tracker which can be adapted to a wide variety of different space flight applications through software changes only. The STELLAR determines two-axis star positions by computing the element and the interelement interpolated centroid positions of the star images. As many as 10 stars may be tracked simultaneously, providing significantly increased stability and accuracy. A detailed description of the STELLAR is presented along with measurements of system performance obtained from an operating breadboard model.

  17. Combinations of 148 navigation stars and the star tracker

    NASA Technical Reports Server (NTRS)

    Duncan, R.

    1980-01-01

    The angular separation of all star combinations for 148 nav star on the onboard software for space transportation system-3 flight and following missions is presented as well as the separation of each pair that satisfies the viewing constraints of using both star trackers simultaneously. Tables show (1) shuttle star catalog 1980 star position in M 1950 coordinates; (2) two star combination of 148 nav stars; and (3) summary of two star-combinations of the star tracker 5 deg filter. These 148 stars present 10,875 combinations. For the star tracker filters of plus or minus 5 deg, there are 875 combinations. Formalhaut (nav star 26) has the best number of combinations, which is 33.

  18. Star Tracker Performance Estimate with IMU

    NASA Technical Reports Server (NTRS)

    Aretskin-Hariton, Eliot D.; Swank, Aaron J.

    2015-01-01

    A software tool for estimating cross-boresight error of a star tracker combined with an inertial measurement unit (IMU) was developed to support trade studies for the Integrated Radio and Optical Communication project (iROC) at the National Aeronautics and Space Administration Glenn Research Center. Typical laser communication systems, such as the Lunar Laser Communication Demonstration (LLCD) and the Laser Communication Relay Demonstration (LCRD), use a beacon to locate ground stations. iROC is investigating the use of beaconless precision laser pointing to enable laser communication at Mars orbits and beyond. Precision attitude knowledge is essential to the iROC mission to enable high-speed steering of the optical link. The preliminary concept to achieve this precision attitude knowledge is to use star trackers combined with an IMU. The Star Tracker Accuracy (STAcc) software was developed to rapidly assess the capabilities of star tracker and IMU configurations. STAcc determines the overall cross-boresight error of a star tracker with an IMU given the characteristic parameters: quantum efficiency, aperture, apparent star magnitude, exposure time, field of view, photon spread, detector pixels, spacecraft slew rate, maximum stars used for quaternion estimation, and IMU angular random walk. This paper discusses the supporting theory used to construct STAcc, verification of the program and sample results.

  19. Star spot location estimation using Kalman filter for star tracker.

    PubMed

    Liu, Hai-bo; Yang, Jian-kun; Wang, Jiong-qi; Tan, Ji-chun; Li, Xiu-jian

    2011-04-20

    Star pattern recognition and attitude determination accuracy is highly dependent on star spot location accuracy for the star tracker. A star spot location estimation approach with the Kalman filter for a star tracker has been proposed, which consists of three steps. In the proposed approach, the approximate locations of the star spots in successive frames are predicted first; then the measurement star spot locations are achieved by defining a series of small windows around each predictive star spot location. Finally, the star spot locations are updated by the designed Kalman filter. To confirm the proposed star spot location estimation approach, the simulations based on the orbit data of the CHAMP satellite and the real guide star catalog are performed. The simulation results indicate that the proposed approach can filter out noises from the measurements remarkably if the sampling frequency is sufficient. PMID:21509065

  20. Optical contacting for gravity probe star tracker

    NASA Technical Reports Server (NTRS)

    Wright, J. J.; Zissa, D. E.

    1984-01-01

    A star-tracker telescope, constructed entirely of fused silica elements optically contacted together, has been proposed to provide submilliarc-second pointing accuracy for Gravity Probe. A bibliography and discussion on optical contacting (the bonding of very flat, highly polished surfaces without the use of adhesives) are presented. Then results from preliminary experiments on the strength of optical contacts including a tensile strength test in liquid helium are discussed. Suggestions are made for further study to verify an optical contacting method for the Gravity Probe star-tracker telescope.

  1. Intelligent error correction method applied on an active pixel sensor based star tracker

    NASA Astrophysics Data System (ADS)

    Schmidt, Uwe

    2005-10-01

    Star trackers are opto-electronic sensors used on-board of satellites for the autonomous inertial attitude determination. During the last years star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The active pixel sensor (APS) technology, introduced in the early 90-ties, allows now the beneficial replacement of CCD detectors by APS detectors with respect to performance, reliability, power, mass and cost. The company's heritage in star tracker design started in the early 80-ties with the launch of the worldwide first fully autonomous star tracker system ASTRO1 to the Russian MIR space station. Jena-Optronik recently developed an active pixel sensor based autonomous star tracker "ASTRO APS" as successor of the CCD based star tracker product series ASTRO1, ASTRO5, ASTRO10 and ASTRO15. Key features of the APS detector technology are, a true xy-address random access, the multiple windowing read out and the on-chip signal processing including the analogue to digital conversion. These features can be used for robust star tracking at high slew rates and under worse conditions like stray light and solar flare induced single event upsets. A special algorithm have been developed to manage the typical APS detector error contributors like fixed pattern noise (FPN), dark signal non-uniformity (DSNU) and white spots. The algorithm works fully autonomous and adapts to e.g. increasing DSNU and up-coming white spots automatically without ground maintenance or re-calibration. In contrast to conventional correction methods the described algorithm does not need calibration data memory like full image sized calibration data sets. The application of the presented algorithm managing the typical APS detector error contributors is a key element for the design of star trackers for long term satellite applications like

  2. Instrument Pointing System /IPS/ - Star trackers

    NASA Astrophysics Data System (ADS)

    Doittau, F. X.; Jamet, J. L.; Vite, M.

    An image dissector tube high accuracy star/sun tracker has been designed for the Spacelab Instrument Pointing System recalibration. Stars with up to mv equals plus eight can be acquired and tracked in a 2 x 2 deg field. Accuracy, (noise excluded) is 0.75 arcsec, rss 3 std dev and noise is less than 0.65 arcsec rms for a mv equals plus eight star. Two-star operation is possible without modification and the sun can also be tracked using a special attachment. Three star sensors equip the Instrument Pointing System and each sensor delivers two-axis coordinates of the selected object (star or sun) which is acquired and tracked in its field of view. These coordinates are processed by the Spacelab onboard computer in order to drive properly the motors actuating the experiment package, for aiming at the desired direction.

  3. Precision Pointing Control System (PPCS) star tracker test

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Tests performed on the TRW precision star tracker are described. The unit tested was a two-axis gimballed star tracker designed to provide star LOS data to an accuracy of 1 to 2 sec. The tracker features a unique bearing system and utilizes thermal and mechanical symmetry techniques to achieve high precision which can be demonstrated in a one g environment. The test program included a laboratory evaluation of tracker functional operation, sensitivity, repeatibility, and thermal stability.

  4. Rover odometry aided by a star tracker

    NASA Astrophysics Data System (ADS)

    Gammell, J. D.; Tong, Chi Hay; Berczi, P.; Anderson, S.; Barfoot, T. D.; Enright, J.

    This paper develops a practical framework for estimating rover position in full-dark conditions by correcting relative odometric estimates with periodic, absolute-attitude measurements from a star tracker. The framework is validated using just under 2.5 kilometres of field data gathered at the University of Toronto's Koffler Scientific Reserve at Jokers Hill (KSR) comprised of both wheel odometry and lidar-based Visual Odometry (VO). It is shown that for the wheel odometry solution, the final estimate of rover position was within 21 metres of the groundtruth as calculated by a differential GPS receiver, or 0.85% of the total traverse distance. When the star tracker measurements are artificially limited to occurring approximately every 250 metres, the algorithm still performs well, giving a final position error of 75.8 metres or 3.0%. Preliminary results to replace wheel odometry with lidar-based VO for the development a full-dark visual solution are also presented. The lidar-based VO solution is shown to be capable of outperforming wheel odometry, but more work is required to develop methods to handle the variety of terrain conditions encountered.

  5. A Heavy Flavor Tracker for STAR

    SciTech Connect

    Chasman, C.; Beavis, D.; Debbe, R.; Lee, J.H.; Levine, M.J.; Videbaek, F.; Xu, Z.; Kleinfelder, S.; Li, S.; Cendejas, R.; Huang, H.; Sakai, S.; Whitten, C.; Joseph, J.; Keane, D.; Margetis, S.; Rykov, V.; Zhang, W.M.; Bystersky, M.; Kapitan, J.; Kushpil, V.; Sumbera, M.; Baudot, J.; Hu-Guo, C.; Shabetai, A.; Szelezniak, M.; Winter, M.; Kelsey, J.; Milner, R.; Plesko, M.; Redwine, R.; Simon, F.; Surrow, B.; Van Nieuwenhuizen, G.; Anderssen, E.; Dong, X.; Greiner, L.; Matis, H.S.; Morgan, S.; Ritter, H.G.; Rose, A.; Sichtermann, E.; Singh, R.P.; Stezelberger, T.; Sun, X.; Thomas, J.H.; Tram, V.; Vu, C.; Wieman, H.H.; Xu, N.; Hirsch, A.; Srivastava, B.; Wang, F.; Xie, W.; Bichsel, H.

    2008-02-25

    The STAR Collaboration proposes to construct a state-of-the-art microvertex detector,the Heavy Flavor Tracker (HFT), utilizing active pixel sensors and silicon strip technology. The HFT will significantly extend the physics reach of the STAR experiment for precision measurement of the yields and spectra of particles containing heavy quarks. This will be accomplished through topological identification of D mesons by reconstruction of their displaced decay vertices with a precision of approximately 50 mu m in p+p, d+A, and A+A collisions. The HFT consists of 4 layers of silicon detectors grouped into two sub-systems with different technologies, guaranteeing increasing resolution when tracking from the TPC and the Silicon Strip Detector (SSD) towards the vertex of the collision. The Intermediate Silicon Tracker (IST), consisting of two layers of single-sided strips, is located inside the SSD. Two layers of Silicon Pixel Detector (PIXEL) are inside the IST. The PIXEL detectors have the resolution necessary for a precision measurement of the displaced vertex. The PIXEL detector will use CMOS Active Pixel Sensors (APS), an innovative technology never used before in a collider experiment. The APSsensors are only 50 mu m thick and at a distance of only 2.5 cm from the interaction point. This opens up a new realm of possibilities for physics measurements. In particular, a thin detector (0.28percent radiation length per layer) in STAR makes it possible to do the direct topological reconstruction of open charm hadrons down to very low pT by the identification of the charged daughters of the hadronic decay.

  6. A low-cost, CCD solid state star tracker

    NASA Technical Reports Server (NTRS)

    Chmielowski, M.; Wynne, D.

    1992-01-01

    Applied Research Corporation (ARC) has developed an engineering model of a multi-star CCD-based tracker for space applications requiring radiation hardness, high reliability and low power consumption. The engineering unit compared favorably in functional performance tests to the standard NASA single-star tracker. Characteristics of the ARC star tracker are: field of view = 10 deg x 7.5 deg, sensitivity range of -1 to +5 star magnitude, NEA = 3 in x 3 in, linearity = 5 in x 5 in, and power consumption of 1-3 W (operating mode dependent). The software is upgradable through a remote link. The hardware-limited acquisition rate is 1-5 Hz for stars of +2 to +5 magnitude and 10-30 Hz for -1 to +2 magnitude stars. Mechanical and electrical interfaces are identical to the standard NASA star tracker.

  7. High Energy Astronomy Observatory star tracker search program

    NASA Technical Reports Server (NTRS)

    Weiler, W. J.

    1972-01-01

    The development of a control system to accommodate the scientific payload of the High Energy Astronomy Observatory (HEAO) is discussed. One of the critical elements of the system is the star tracker subsystem, which defines an accurate three-axis attitude reference. A digital computer program has been developed to evaluate the ability of a particular star tracker configuration to meet the requirements for attitude reference at various vehicle orientations. Used in conjuction with an adequate star catalog, the computer program provides information on availability of stars for each tracker and on the ability of the system to maintain three-axis attitude reference throughout a representative sequence of vehicle orientations.

  8. Forward GEM Tracker (FGT) at STAR

    NASA Astrophysics Data System (ADS)

    Surrow, Bernd

    2012-10-01

    As part of our program to understand the internal structure of the proton, we have and will continue mid-rapidity (-1<η<1) W and di-jet measurements in p+p collisions at √s = 500GeV. The ongoing STAR W program is exploring the longitudinal spin contribution of anti-u and anti-d quarks to the proton spin. The gluon spin contribution can be probed through di-jet measurements. The Forward GEM Tracker (FGT) at STAR will enhance the charged sign separation for high pT tracks in the pseudo-rapidity range of 1.0<η<2.0, and therefore allows an extension of W and di-jet measurements at forward pseudo-rapidity. We will present the status of the FGT assembly and completion along with projections for future W and di-jet measurements. We will discuss studies that explore the possibilities of using the FGT to reconstruct jets in the forward direction.

  9. 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

  10. 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

  11. EOS attitude determination and next generation star tracker enhancements

    NASA Technical Reports Server (NTRS)

    Kudva, P.; Throckmorton, A.

    1993-01-01

    The pointing knowledge required for the Earth Observing System (EOS) AM mission is at the limit of the current generation of star trackers, with little margin. Techniques for improving the performance of existing star trackers are explored, with performance sensitivities developed for each alternative. These are extended to define the most significant performance enhancements for a next generation star tracker. Since attitude determination studies tend to be computationally intensive, an approach for using a simpler one degree of freedom formulation is contrasted with a full three degree of freedom formulation. Additionally, covariance analysis results are compared with time domain simulation performance results.

  12. The research on image processing technology of the star tracker

    NASA Astrophysics Data System (ADS)

    Li, Yu-ming; Li, Chun-jiang; Zheng, Ran; Li, Xiao; Yang, Jun

    2014-11-01

    As the core of visual sensitivity via imaging, image processing technology, especially for star tracker, is mainly characterized by such items as image exposure, optimal storage, background estimation, feature correction, target extraction, iteration compensation. This paper firstly summarizes the new research on those items at home and abroad, then, according to star tracker's practical engineering, environment in orbit and lifetime information, shows an architecture about rapid fusion between multiple frame images, which can be used to restrain oversaturation of the effective pixels, which means star tracker can be made more precise, more robust and more stable.

  13. Development and Performance Characterization of Colour Star Trackers

    NASA Astrophysics Data System (ADS)

    McVittie, Geoffrey

    Star trackers provide an essential component to a satellite mission requiring high-precision and high-accuracy attitude measurements. A star tracker operates by taking pictures of the celestial sphere and attempting to identify the stars in the image using a combination of the geometric and brightness patterns. The star-positions in the image then determine the attitude of the sensor in the inertial frame. I propose extending the capability of star trackers by including the colour properties of the stars into the star identification process; hence, colour star tracking. Current generation star trackers exist in a variety of forms, with a variety of additional potential designs and operational algorithms proposed in the literature. However, they all share the common trait of using a combination of geometric and monochrome brightness derived patterns to identify stars. Including colour information with the geometric and brightness properties into the identification process represents a new branch in the field of star tracker design. The process of measuring colour also causes a reduction in the amount of light gathered by the sensor, decreasing the number of stars observed. The challenge in colour star tracking becomes establishing that the additional information provided by colour to star patterns is greater than the loss of observable stars due to the measurement process. While superficially brief, accomplishing it touches upon a wide range of topic areas. This includes most research developed for monochromatic star trackers including imaging hardware, optics, noise rejection, parameter estimation, signal detection, data mining, pattern matching, and astronomy. Additionally, using colour necessitates introducing the topics of stellar photometry, spectral filtering, and colour imaging. The approach to colour star tracker development, presented here, considers three aspects to the operation of the technology: colour measurement, star detection, and star pattern

  14. Simulation analysis of dynamic working performance for star trackers.

    PubMed

    Shen, Juan; Zhang, Guangjun; Wei, Xinguo

    2010-12-01

    The elongated imaging track pertaining to a star spot recorded in the image sensor of a star tracker will diffuse over several pixels at a high angular velocity, leading to an inaccurate, even false, attitude value. A computer simulation of the attitude determination from a dynamic star tracker is developed first, based on a dynamic mathematical model of the star-spot imaging and an efficiency validation of the star centroiding algorithm in the dynamic condition. Then major error sources affecting the attitude accuracy in the dynamic condition are analyzed and discussed systematically based on the simulation results. A mathematical model calculating the average star number detected in the field of view is also deduced, using simulation results and signal processing theory, with image trailing ranging from 0 to 20 pixels during exposure. The summarized regularity is helpful in the system design and accuracy evaluation of a star tracker. PMID:21119749

  15. Lost in space: Onboard star identification using CCD star tracker data without an a priori attitude

    NASA Technical Reports Server (NTRS)

    Ketchum, Eleanor A.; Tolson, Robert H.

    1993-01-01

    There are many algorithms in use today which determine spacecraft attitude by identifying stars in the field of view of a star tracker. Some methods, which date from the early 1960's, compare the angular separation between observed stars with a small catalog. In the last 10 years, several methods have been developed which speed up the process and reduce the amount of memory needed, a key element to onboard attitude determination. However, each of these methods require some a priori knowledge of the spacecraft attitude. Although the Sun and magnetic field generally provide the necessary coarse attitude information, there are occasions when a spacecraft could get lost when it is not prudent to wait for sunlight. Also, the possibility of efficient attitude determination using only the highly accurate CCD star tracker could lead to fully autonomous spacecraft attitude determination. The need for redundant coarse sensors could thus be eliminated at substantial cost reduction. Some groups have extended their algorithms to implement a computation intense full sky scan. Some require large data bases. Both storage and speed are concerns for autonomous onboard systems. Neural network technology is even being explored by some as a possible solution, but because of the limited number of patterns that can be stored and large overhead, nothing concrete has resulted from these efforts. This paper presents an algorithm which, by descretizing the sky and filtering by visual magnitude of the brightness observed star, speeds up the lost in space star identification process while reducing the amount of necessary onboard computer storage compared to existing techniques.

  16. Optical Alignment of the Global Precipitation Measurement (GPM) Star Trackers

    NASA Technical Reports Server (NTRS)

    Hetherington, Samuel; Osgood, Dean; McMann, Joe; Roberts, Viki; Gill, James; Mclean, Kyle

    2013-01-01

    The optical alignment of the star trackers on the Global Precipitation Measurement (GPM) core spacecraft at NASA Goddard Space Flight Center (GSFC) was challenging due to the layout and structural design of the GPM Lower Bus Structure (LBS) in which the star trackers are mounted as well as the presence of the star tracker shades that blocked line-of-sight to the primary star tracker optical references. The initial solution was to negotiate minor changes in the original LBS design to allow for the installation of a removable item of ground support equipment (GSE) that could be installed whenever measurements of the star tracker optical references were needed. However, this GSE could only be used to measure secondary optical reference cube faces not used by the star tracker vendor to obtain the relationship information and matrix transformations necessary to determine star tracker alignment. Unfortunately, due to unexpectedly large orthogonality errors between the measured secondary adjacent cube faces and the lack of cube calibration data, we required a method that could be used to measure the same reference cube faces as originally measured by the vendor. We describe an alternative technique to theodolite auto-collimation for measurement of an optical reference mirror pointing direction when normal incidence measurements are not possible. This technique was used to successfully align the GPM star trackers and has been used on a number of other NASA flight projects. We also discuss alignment theory as well as a GSFC-developed theodolite data analysis package used to analyze angular metrology data.

  17. On-Orbit Solar Dynamics Observatory (SDO) Star Tracker Warm Pixel Analysis

    NASA Technical Reports Server (NTRS)

    Felikson, Denis; Ekinci, Matthew; Hashmall, Joseph A.; Vess, Melissa

    2011-01-01

    This paper describes the process of identification and analysis of warm pixels in two autonomous star trackers on the Solar Dynamics Observatory (SDO) mission. A brief description of the mission orbit and attitude regimes is discussed and pertinent star tracker hardware specifications are given. Warm pixels are defined and the Quality Index parameter is introduced, which can be explained qualitatively as a manifestation of a possible warm pixel event. A description of the algorithm used to identify warm pixel candidates is given. Finally, analysis of dumps of on-orbit star tracker charge coupled devices (CCD) images is presented and an operational plan going forward is discussed. SDO, launched on February 11, 2010, is operated from the NASA Goddard Space Flight Center (GSFC). SDO is in a geosynchronous orbit with a 28.5 inclination. The nominal mission attitude points the spacecraft X-axis at the Sun, with the spacecraft Z-axis roughly aligned with the Solar North Pole. The spacecraft Y-axis completes the triad. In attitude, SDO moves approximately 0.04 per hour, mostly about the spacecraft Z-axis. The SDO star trackers, manufactured by Galileo Avionica, project the images of stars in their 16.4deg x 16.4deg fields-of-view onto CCD detectors consisting of 512 x 512 pixels. The trackers autonomously identify the star patterns and provide an attitude estimate. Each unit is able to track up to 9 stars. Additionally, each tracker calculates a parameter called the Quality Index, which is a measure of the quality of the attitude solution. Each pixel in the CCD measures the intensity of light and a warns pixel is defined as having a measurement consistently and significantly higher than the mean background intensity level. A warns pixel should also have lower intensity than a pixel containing a star image and will not move across the field of view as the attitude changes (as would a dim star image). It should be noted that the maximum error introduced in the star tracker

  18. Improved autonomous star identification algorithm

    NASA Astrophysics Data System (ADS)

    Luo, Li-Yan; Xu, Lu-Ping; Zhang, Hua; Sun, Jing-Rong

    2015-06-01

    The log-polar transform (LPT) is introduced into the star identification because of its rotation invariance. An improved autonomous star identification algorithm is proposed in this paper to avoid the circular shift of the feature vector and to reduce the time consumed in the star identification algorithm using LPT. In the proposed algorithm, the star pattern of the same navigation star remains unchanged when the stellar image is rotated, which makes it able to reduce the star identification time. The logarithmic values of the plane distances between the navigation and its neighbor stars are adopted to structure the feature vector of the navigation star, which enhances the robustness of star identification. In addition, some efforts are made to make it able to find the identification result with fewer comparisons, instead of searching the whole feature database. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition rate and robustness by the proposed algorithm are better than those by the LPT algorithm and the modified grid algorithm. Project supported by the National Natural Science Foundation of China (Grant Nos. 61172138 and 61401340), the Open Research Fund of the Academy of Satellite Application, China (Grant No. 2014_CXJJ-DH_12), the Fundamental Research Funds for the Central Universities, China (Grant Nos. JB141303 and 201413B), the Natural Science Basic Research Plan in Shaanxi Province, China (Grant No. 2013JQ8040), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130203120004), and the Xi’an Science and Technology Plan, China (Grant. No CXY1350(4)).

  19. System and method for calibrating inter-star-tracker misalignments in a stellar inertial attitude determination system

    NASA Technical Reports Server (NTRS)

    Li, Rongsheng (Inventor); Wu, Yeong-Wei Andy (Inventor); Hein, Douglas H. (Inventor)

    2004-01-01

    A method and apparatus for determining star tracker misalignments is disclosed. The method comprises the steps of defining a defining a reference frame for the star tracker assembly according to a boresight of the primary star tracker and a boresight of a second star tracker wherein the boresight of the primary star tracker and a plane spanned by the boresight of the primary star tracker and the boresight of the second star tracker at least partially define a datum for the reference frame for the star tracker assembly; and determining the misalignment of the at least one star tracker as a rotation of the defined reference frame.

  20. A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

    PubMed Central

    Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

    2014-01-01

    Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

  1. A brightness-referenced star identification algorithm for APS star trackers.

    PubMed

    Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

    2014-01-01

    Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4~5 times that of the pyramid method and 35~37 times that of the geometric method. PMID:25299950

  2. Space shuttle orbiter vehicle star tracker test program plan

    NASA Technical Reports Server (NTRS)

    Smith, R. A.

    1974-01-01

    The development model test program was written to provide guidance for essential star tracker test support to the Space Shuttle Orbiter Program. The program organization included test equipment preparation, prototype baseline/acceptance tests, prototype total performance tests, and prototype special tests. Test configurations, preparation phase, documentation, scheduling, and manpower requirements are discussed. The test program permits an early evaluation of the tracker's performance prior to completion and testing of the final flight models.

  3. Miniature wide field-of-view star trackers for spacecraft attitude sensing and navigation

    NASA Technical Reports Server (NTRS)

    Mccarty, William; Curtis, Eric; Hull, Anthony; Morgan, William

    1993-01-01

    Introducing a family of miniature, wide field-of-view star trackers for low cost, high performance spacecraft attitude determination and navigation applications. These devices, derivative of the WFOV Star Tracker Camera developed cooperatively by OCA Applied Optics and the Lawrence Livermore National Laboratory for the Brilliant Pebbles program, offer a suite of options addressing a wide range of spacecraft attitude measurement and control requirements. These sensors employ much wider fields than are customary (ranging between 20 and 60 degrees) to assure enough bright stars for quick and accurate attitude determinations without long integration intervals. The key benefit of this approach are light weight, low power, reduced data processing loads and high information carrier rates for wide ACS bandwidths. Devices described range from the proven OCA/LLNL WFOV Star Tracker Camera (a low-cost, space-qualified star-field imager utilizing the spacecraft's own computer and centroiding and position-finding), to a new autonomous subsystem design featuring dual-redundant cameras and completely self-contained star-field data processing with output quaternion solutions accurate to 100 micro-rad, 3 sigma, for stand-alone applications.

  4. Star tracker operation in a high density proton field

    NASA Technical Reports Server (NTRS)

    Miklus, Kenneth J.; Kissh, Frank; Flynn, David J.

    1993-01-01

    Algorithms that reject transient signals due to proton effects on charge coupled device (CCD) sensors have been implemented in the HDOS ASTRA-l Star Trackers to be flown on the TOPEX mission scheduled for launch in July 1992. A unique technique for simulating a proton-rich environment to test trackers is described, as well as the test results obtained. Solar flares or an orbit that passes through the South Atlantic Anomaly can subject the vehicle to very high proton flux levels. There are three ways in which spurious proton generated signals can impact tracker performance: the many false signals can prevent or extend the time to acquire a star; a proton-generated signal can compromise the accuracy of the star's reported magnitude and position; and the tracked star can be lost, requiring reacquisition. Tests simulating a proton-rich environment were performed on two ASTRA-1 Star Trackers utilizing these new algorithms. There were no false acquisitions, no lost stars, and a significant reduction in reported position errors due to these improvements.

  5. A star pattern recognition algorithm for autonomous attitude determination

    NASA Technical Reports Server (NTRS)

    Van Bezooijen, R. W. H.

    1990-01-01

    The star-pattern recognition algorithm presented allows the advanced Full-sky Autonomous Star Tracker (FAST) device, such as the projected ASTROS II system of the Mariner Mark II planetary spacecraft, to reliably ascertain attitude about all three axes. An ASTROS II-based FAST, possessing an 11.5 x 11.5 deg field of view and 8-arcsec accuracy, can when integrated with an all-sky data base of 4100 guide stars determine its attitude in about 1 sec, with a success rate close to 100 percent. The present recognition algorithm can also be used for automating the acquisition of celestial targets by astronomy telescopes, autonomously updating the attitude of gyro-based attitude control systems, and automating ground-based attitude reconstruction.

  6. Simulations of silicon vertex tracker for star experiment at RHIC

    SciTech Connect

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W.; Liko, D.; Cramer, J.; Prindle, D.; Trainor, T.; Braithwaite, W.

    1991-12-31

    The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.

  7. Star tracker error analysis: Roll-to-pitch nonorthogonality

    NASA Technical Reports Server (NTRS)

    Corson, R. W.

    1979-01-01

    An error analysis is described on an anomaly isolated in the star tracker software line of sight (LOS) rate test. The LOS rate cosine was found to be greater than one in certain cases which implied that either one or both of the star tracker measured end point unit vectors used to compute the LOS rate cosine had lengths greater than unity. The roll/pitch nonorthogonality matrix in the TNB CL module of the IMU software is examined as the source of error.

  8. ASTROS - A sub-arcsec CCD star tracker

    NASA Technical Reports Server (NTRS)

    Stanton, R. H.; Alexander, J. W.; Dennison, E. W.; Glavich, T. A.; Salomon, P. M.

    1984-01-01

    The design and application of ASTROS (Advanced Star and Target Reference Optical Sensor) are described, with emphasis on performance test results acquired with a prototype system. The ASTROS tracker provides extremely precise measurements of star image coordinates as inputs to the Image Motion Compensation (IMC) system used to stabilize the science instrument focal planes. Performance levels achieved are dramatic improvements over the levels achieved with image dissector designs with comparable fields of view.

  9. Dynamic imaging model and parameter optimization for a star tracker.

    PubMed

    Yan, Jinyun; Jiang, Jie; Zhang, Guangjun

    2016-03-21

    Under dynamic conditions, star spots move across the image plane of a star tracker and form a smeared star image. This smearing effect increases errors in star position estimation and degrades attitude accuracy. First, an analytical energy distribution model of a smeared star spot is established based on a line segment spread function because the dynamic imaging process of a star tracker is equivalent to the static imaging process of linear light sources. The proposed model, which has a clear physical meaning, explicitly reflects the key parameters of the imaging process, including incident flux, exposure time, velocity of a star spot in an image plane, and Gaussian radius. Furthermore, an analytical expression of the centroiding error of the smeared star spot is derived using the proposed model. An accurate and comprehensive evaluation of centroiding accuracy is obtained based on the expression. Moreover, analytical solutions of the optimal parameters are derived to achieve the best performance in centroid estimation. Finally, we perform numerical simulations and a night sky experiment to validate the correctness of the dynamic imaging model, the centroiding error expression, and the optimal parameters. PMID:27136791

  10. Clementine Star Tracker Stellar Compass: Final report part 1

    SciTech Connect

    Priest, R.E.; Kordas, J.F.; Lewis, I.T.

    1995-07-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star stracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 focal plane array and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {mu}rad pitch and yaw and 450 {mu}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights. Documentation generated during the design, analysis, build, test and characterization of the star tracker cameras are presented. Collectively, this documentation represents a small library of information for this camera, and may be used as a framework for producing copy units by commercial enterprises, and therefore satisfies a Department of Defense and Department of Energy goal to transfer technology to industry. However, the considerable knowledge gained from the experience of the individuals involved in the system trades, design, analysis, production, testing and characterization of the star tracker stellar compass is not contained in this documentation.

  11. A precision star tracker utilizing advanced techniques and materials

    NASA Technical Reports Server (NTRS)

    Gates, R. F.; Mcaloon, K. J.

    1976-01-01

    An image dissector star tracker has been developed which operates in the photon counting mode making it possible to utilize all digital electronics. A unique pulse processing circuit allows bright stars to be tracked as well as dim stars. Thermal mechanical stability has been greatly enhanced by fabricating a housing with graphite/epoxy composite material with a linear coefficient of thermal expansion near zero. Test results indicate the +10 Mv stars can be acquired and tracked, while position variation with star intensity is less than 2 arc seconds from 2.5 Mv to +10 Mv. The noise equivalent angle for a +8 Mv star is 3 arc seconds. Polynominal correction for remaining cross-coupling and nonlinearity reduced error over total 1 x 1 deg field to 1.5 arc seconds.

  12. Star tracker stellar compass for the Clementine mission

    SciTech Connect

    Kordas, J.F.; Lewis, I.T.; Wilson, B.A.

    1995-04-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star tracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 FPA and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {micro}rad pitch and yaw and 450 {micro}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

  13. The ST5000: a high-precision star tracker and attitude determination system

    NASA Astrophysics Data System (ADS)

    Percival, Jeffrey W.; Nordsieck, Kenneth H.; Jaehnig, Kurt P.

    2008-07-01

    The University of Wisconsin's Space Astronomy Laboratory has designed and built a Star Tracker suitable for use on sounding rockets and class D satellites. This device brings together autonomous attitude determination ("Lost in Space" mode), multi-star tracking, and a novel form of Progressive Image Transmission (US patent #5,991,816), which allows the device to be used as an ultra-low bandwidth imager. The Star Tracker 5000 (ST5000) reached operational status in a suborbital sounding rocket flight in August 2007. The ST5000 determined the rocket's inertial (FK5) attitude with arcsecond precision using its autonomous attitude determination capability, and then provided continuous sub-arc-second tracking for the full 360-second on-target portion of the flight. The ST5000 RMS tracking error was 0.54 arc-seconds in yaw and pitch, and 17 arc-seconds in roll. The vehicle RMS jitter was 0.5 arc-seconds in yaw and pitch, and 10 arc-seconds in roll. The ST5000 was funded by NASA grants NAG5-7026 and NAG5-8588.

  14. Acquisition and track algorithms for the Astros star tracker

    NASA Technical Reports Server (NTRS)

    Shalom, E.; Alexander, J. W.; Stanton, R. H.

    1985-01-01

    The Astros star tracker has been designed for an employment with the Space Shuttle. An achievement of the performance levels needed has required critical trade-offs between the hardware design and the control algorithms. This paper provides a description of the development of the acquisition and track algorithms. Attention is given to an Astros system overview, a system firmware description, cluster evaluation, guide star selection, exposure time determination, video data input, update interval timing, exposure time sequencing full frame video A/D conversion, analog threshold for acquisition, minimum threshold determination, and the theoretical basis for the track algorithm.

  15. 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

  16. Precision Attitude Determination System (PADS) system design and analysis: Single-axis gimbal star tracker

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.

  17. The STAR Heavy Flavor Tracker PXL detector readout electronics

    NASA Astrophysics Data System (ADS)

    Schambach, J.; Contin, G.; Greiner, L.; Stezelberger, T.; Sun, X.; Szelezniak, M.; Vu, C.

    2016-01-01

    The Heavy Flavor Tracker (HFT) is a recently installed micro-vertex detector upgrade to the STAR experiment at RHIC, consisting of three subsystems with various technologies of silicon sensors arranged in 4 concentric cylinders. The two innermost layers of the HFT close to the beam pipe, the Pixel ("PXL") subsystem, employ CMOS Monolithic Active Pixel Sensor (MAPS) technology that integrate the sensor, front-end electronics, and zero-suppression circuitry in one silicon die. This paper presents selected characteristics of the PXL detector part of the HFT and the hardware, firmware and software associated with the readout system for this detector.

  18. Adaptive Neural Star Tracker Calibration for Precision Spacecraft Pointing and Tracking

    NASA Technical Reports Server (NTRS)

    Bayard, David S.

    1996-01-01

    The Star Tracker is an essential sensor for precision pointing and tracking in most 3-axis stabilized spacecraft. In the interest (of) improving pointing performance by taking advantage of dramatic increases in flight computer power and memory anticipated over the next decade, this paper investigates the use of a neural net for adaptive in-flight calibration of the Star Tracker.

  19. Optimal estimation for the satellite attitude using star tracker measurements

    NASA Technical Reports Server (NTRS)

    Lo, J. T.-H.

    1986-01-01

    An optimal estimation scheme is presented, which determines the satellite attitude using the gyro readings and the star tracker measurements of a commonly used satellite attitude measuring unit. The scheme is mainly based on the exponential Fourier densities that have the desirable closure property under conditioning. By updating a finite and fixed number of parameters, the conditional probability density, which is an exponential Fourier density, is recursively determined. Simulation results indicate that the scheme is more accurate and robust than extended Kalman filtering. It is believed that this approach is applicable to many other attitude measuring units. As no linearization and approximation are necessary in the approach, it is ideal for systems involving high levels of randomness and/or low levels of observability and systems for which accuracy is of overriding importance.

  20. Angular velocity estimation from measurement vectors of star tracker.

    PubMed

    Liu, Hai-bo; Yang, Jun-cai; Yi, Wen-jun; Wang, Jiong-qi; Yang, Jian-kun; Li, Xiu-jian; Tan, Ji-chun

    2012-06-01

    In most spacecraft, there is a need to know the craft's angular rate. Approaches with least squares and an adaptive Kalman filter are proposed for estimating the angular rate directly from the star tracker measurements. In these approaches, only knowledge of the vector measurements and sampling interval is required. The designed adaptive Kalman filter can filter out noise without information of the dynamic model and inertia dyadic. To verify the proposed estimation approaches, simulations based on the orbit data of the challenging minisatellite payload (CHAMP) satellite and experimental tests with night-sky observation are performed. Both the simulations and experimental testing results have demonstrated that the proposed approach performs well in terms of accuracy, robustness, and performance. PMID:22695598

  1. Star trackers, star catalogs, and attitude determination - Probabilistic aspects of system design

    NASA Technical Reports Server (NTRS)

    Vedder, John D.

    1992-01-01

    Optimizing spacecraft attitude determination systems that use onboard star trackers requires analysis and evaluation of some probabilistic aspects of system design. This paper discusses methods of constructing or compiling optimum star catalogs, which are defined as uniform distributions on a sphere. Both local and global measures of uniformity on a sphere are defined. Application of these methods and measures to a specific problem is also discussed. In addition, Poisson models of star tracker acquisition probabilities are formulated to provide a useful analytical basis for designing and optimizing attitude determination systems. These analytical models and methods lead to rapid and realistic quantitative results, and should therefore facilitate making system performance trades. Use of such methods should also reduce the need for performing tedious computer simulations to obtain analogous results.

  2. Features of design and development of the optical head of star tracker

    NASA Astrophysics Data System (ADS)

    Moldabekov, M.; Akhmedov, D.; Yelubayev, S.; Ten, V.; Albazarov, B.; Shamro, Alexander; Alipbayev, Kuanysh; Bopeyev, Timur; Sukhenko, A.

    2014-10-01

    The paper presents an approach to the design and development of the optical head of the star tracker and its hood for satellites. The main stages of the optical system design including development of requirements, selection of the optical system by analyzing with help of CAD, hood design with help of simulation, as well as the main stages of its components(lenses) manufacturing and control of quality of manufacturing the optical system are described. Engineering model of the optical head of star tracker which can be used as the basis for the development of the star tracker prototype for use in Kazakhstan's satellites was developed in accordance with the requirements.

  3. Compensation for Time-Dependent Star Tracker Thermal Deformation on the Aqua Spacecraft

    NASA Technical Reports Server (NTRS)

    Hashmall, Joseph A.; Natanson, Gregory; Glickman, Jonathan; Sedlak, Joseph

    2004-01-01

    Analysis of attitude sensor data from the Aqua mission showed small but systematic differences between batch least-squares and extended Kalman filter attitudes. These differences were also found to be correlated with star tracker residuals, gyro bias estimates, and star tracker baseplate temperatures. This paper describes the analysis that shows that these correlations are all consistent with a single cause: time-dependent thermal deformation of star tracker alignments. These varying alignments can be separated into relative and common components. The relative misalignments can be determined and compensated for. The common misalignments can only be determined in special cases.

  4. Post flight analysis of NASA standard star trackers recovered from the solar maximum mission

    NASA Technical Reports Server (NTRS)

    Newman, P.

    1985-01-01

    The flight hardware returned after the Solar Maximum Mission Repair Mission was analyzed to determine the effects of 4 years in space. The NASA Standard Star Tracker would be a good candidate for such analysis because it is moderately complex and had a very elaborate calibration during the acceptance procedure. However, the recovery process extensively damaged the cathode of the image dissector detector making proper operation of the tracker and a comparison with preflight characteristics impossible. Otherwise, the tracker functioned nominally during testing.

  5. Spacecraft attitude control systems with dynamic methods and structures for processing star tracker signals

    NASA Technical Reports Server (NTRS)

    Liu, Yong (Inventor); Wu, Yeong-Wei Andy (Inventor); Li, Rongsheng (Inventor)

    2001-01-01

    Methods are provided for dynamically processing successively-generated star tracker data frames and associated valid flags to generate processed star tracker signals that have reduced noise and a probability greater than a selected probability P.sub.slctd of being valid. These methods maintain accurate spacecraft attitude control in the presence of spurious inputs (e.g., impinging protons) that corrupt collected charges in spacecraft star trackers. The methods of the invention enhance the probability of generating valid star tracker signals because they respond to a current frame probability P.sub.frm by dynamically selecting the largest valid frame combination whose combination probability P.sub.cmb satisfies a selected probability P.sub.slctd. Noise is thus reduced while the probability of finding a valid frame combination is enhanced. Spacecraft structures are also provided for practicing the methods of the invention.

  6. Improving the WIYN Telescope's pointing and tracking performance with a star tracker camera

    NASA Astrophysics Data System (ADS)

    Rajagopal, Jayadev K.; Harbeck, Daniel R.; Corson, Charles; Abareshi, Behzad; Schweiker, Heidi; Liu, Wilson; Hooper, Eric J.; Percival, Jeffrey W.; Jaehnig, Kurt P.

    2014-07-01

    We report on the implementation of a star tracker camera to improve the telescope pointing and tracking, at the WIYN 3.5 m telescope on Kitt Peak, Arizona. We base the overall concept on a star tracker system developed at the University of Wisconsin and routinely in use now for rocket and high-altitude balloon navigation. This fairly simple system provides pointing and station-keeping information, accurate to a few arcseconds, typically within a second.

  7. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    PubMed Central

    Sun, Ting; Xing, Fei; You, Zheng

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers. PMID:23567527

  8. Optical system error analysis and calibration method of high-accuracy star trackers.

    PubMed

    Sun, Ting; Xing, Fei; You, Zheng

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers. PMID:23567527

  9. Precision Attitude Determination System (PADS) design and analysis. Two-axis gimbal star tracker

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Development of the Precision Attitude Determination System (PADS) focused chiefly on the two-axis gimballed star tracker and electronics design improved from that of Precision Pointing Control System (PPCS), and application of the improved tracker for PADS at geosynchronous altitude. System design, system analysis, software design, and hardware design activities are reported. The system design encompasses the PADS configuration, system performance characteristics, component design summaries, and interface considerations. The PADS design and performance analysis includes error analysis, performance analysis via attitude determination simulation, and star tracker servo design analysis. The design of the star tracker and electronics are discussed. Sensor electronics schematics are included. A detailed characterization of the application software algorithms and computer requirements is provided.

  10. An accuracy measurement method for star trackers based on direct astronomic observation

    PubMed Central

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-01-01

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

  11. An accuracy measurement method for star trackers based on direct astronomic observation

    NASA Astrophysics Data System (ADS)

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-03-01

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

  12. An accuracy measurement method for star trackers based on direct astronomic observation.

    PubMed

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-01-01

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

  13. Autonomous star field identification for robotic solar system exploration

    NASA Astrophysics Data System (ADS)

    Scholl, Marija S.

    A six-feature all-sky star field identification algorithm has been developed. The minimum identifiable star pattern element consists of an oriented star triplet defined by three stars, their celestial coordinates and visual magnitudes. This algorithm has been integrated with a CCD-based imaging camera. The autonomous intelligent camera identifies in real time any star field without a priori knowledge. Observatory tests on star fields with this intelligent camera are described.

  14. Ground Testing Strategies for Verifying the Slew Rate Tolerance of Star Trackers

    PubMed Central

    Dzamba, Tom; Enright, John

    2014-01-01

    The performance of a star tracker is largely based on the availability of its attitude solution. Several methods exist to assess star tracker availability under both static and dynamic imaging conditions. However, these methods typically make various idealizations that can limit the accuracy of these results. This study aims to increase the fidelity of star tracker availability modeling by accounting for the effects of detection logic and pixel saturation on star detection. We achieve this by developing an analytical model for the focal plane intensity distribution of a star in the presence of sensor slew. Using the developed model, we examine the effects of slew rate on star detection using simulations and lab tests. The developed approach allows us to determine the maximum slew rate for which a star of a given stellar magnitude can still be detected. This information can then be used to describe the availability of a star tracker attitude solution as a function of slew rate, both spatially, across the entire celestial sphere, or locally, along a specified orientation track. PMID:24577522

  15. Ground testing strategies for verifying the slew rate tolerance of star trackers.

    PubMed

    Dzamba, Tom; Enright, John

    2014-01-01

    The performance of a star tracker is largely based on the availability of its attitude solution. Several methods exist to assess star tracker availability under both static and dynamic imaging conditions. However, these methods typically make various idealizations that can limit the accuracy of these results. This study aims to increase the fidelity of star tracker availability modeling by accounting for the effects of detection logic and pixel saturation on star detection. We achieve this by developing an analytical model for the focal plane intensity distribution of a star in the presence of sensor slew. Using the developed model, we examine the effects of slew rate on star detection using simulations and lab tests. The developed approach allows us to determine the maximum slew rate for which a star of a given stellar magnitude can still be detected. This information can then be used to describe the availability of a star tracker attitude solution as a function of slew rate, both spatially, across the entire celestial sphere, or locally, along a specified orientation track. PMID:24577522

  16. STAR Images: Image gallery from the Solenoidal Tracker at RHIC

    DOE Data Explorer

    The primary physics task of STAR is to study the formation and characteristics of the quark-gluon plasma (QGP), a state of matter believed to exist at sufficiently high energy densities. STAR consists of several types of detectors, each specializing in detecting certain types of particles or characterizing their motion. These detectors allow final statements to be made about the collision. The gallery of STAR images makes available a small collection of event-generated images from Gold-Beam experiments, a simulation of TCP Drift, and a library of STAR instrument and construction photos.

  17. Magnitude calibration of a fixed head star tracker using Astro-1 flight data

    NASA Technical Reports Server (NTRS)

    Rakoczy, John M.; West, Mark E.

    1992-01-01

    The Astro-1 UV astronomy mission was hampered by the failures of the automatic star acquisition procedure. The acquisition procedure depended on the Instrument Pointing Subsystem's Fixed Head Star Trackers (FHST) to acquire, track and identify guidestars of known visual magnitude. During the Astro-1 mission it was suspected that the star magnitudes measured by the FHST were much lower than predicted. A postflight investigation of the Astro-1 flight data confirmed and quantified this suspicion. Star magnitude calibration curves computed from the flight data depict the variance from the preflight calibration curves. These results are helping engineers to plan improvements to the acquisition procedure for the upcoming Astro-2 mission.

  18. STAR (Solenoidal Tracker at RHIC) Figures and Data

    DOE Data Explorer

    The STAR Collaboration

    The primary physics task of STAR is to study the formation and characteristics of the quark-gluon plasma (QGP), a state of matter believed to exist at sufficiently high energy densities. STAR consists of several types of detectors, each specializing in detecting certain types of particles or characterizing their motion. These detectors work together in an advanced data acquisition and subsequent physics analysis that allows final statements to be made about the collision. The STAR Publications page provides access to all published papers by the STAR Collaboration, and many of them have separate links to the figures and data found in or supporting the paper. See also the data-rich summaries of the research at http://www.star.bnl.gov/central/physics/results/. [See also DDE00230

  19. Application of flight data to Space Shuttle CCD star tracker catalog design

    NASA Technical Reports Server (NTRS)

    Barry, Karen; Hindman, Mark; Yates, Russell

    1993-01-01

    The new Shuttle Solid-State Tracker (SSST) is an improved but transparent replacement for the analog version which has flown on every Shuttle mission. This paper will examine the data collected from four Shuttle flights to establish parameters for selection of acceptable navigation stars, and apply those parameters to establish a star catalog which will be sufficient to ensure the ability of the SSST to perform attitude updates while docked to the Space Station.

  20. Star tracker axis-to-sunlit earth horizon angle constraint evaluations for rendezvous operations

    NASA Technical Reports Server (NTRS)

    Hutchison, W. L.

    1975-01-01

    The results are presented of a study initiated to evaluate the star tracker axis-to-sunlit earth horizon angle constraint with respect to limitations imposed on the passive target rendezvous capability. The data presented include considerations for dispersions and sensor pointing capabilities and generalizations with respect to the uncertainties associated with the angle constraint available in practice.

  1. CMOS Active Pixel Sensor Star Tracker with Regional Electronic Shutter

    NASA Technical Reports Server (NTRS)

    Yadid-Pecht, Orly; Pain, Bedabrata; Staller, Craig; Clark, Christopher; Fossum, Eric

    1996-01-01

    The guidance system in a spacecraft determines spacecraft attitude by matching an observed star field to a star catalog....An APS(active pixel sensor)-based system can reduce mass and power consumption and radiation effects compared to a CCD(charge-coupled device)-based system...This paper reports an APS (active pixel sensor) with locally variable times, achieved through individual pixel reset (IPR).

  2. Deep coupling of star tracker and MEMS-gyro data under highly dynamic and long exposure conditions

    NASA Astrophysics Data System (ADS)

    Sun, Ting; Xing, Fei; You, Zheng; Wang, Xiaochu; Li, Bin

    2014-08-01

    Star trackers and gyroscopes are the two most widely used attitude measurement devices in spacecrafts. The star tracker is supposed to have the highest accuracy in stable conditions among different types of attitude measurement devices. In general, to detect faint stars and reduce the size of the star tracker, a method with long exposure time method is usually used. Thus, under dynamic conditions, smearing of the star image may appear and result in decreased accuracy or even failed extraction of the star spot. This may cause inaccuracies in attitude measurement. Gyros have relatively good dynamic performance and are usually used in combination with star trackers. However, current combination methods focus mainly on the data fusion of the output attitude data levels, which are inadequate for utilizing and processing internal blurred star image information. A method for tracking deep coupling stars and MEMS-gyro data is proposed in this work. The method achieves deep fusion at the star image level. First, dynamic star image processing is performed based on the angular velocity information of the MEMS-gyro. Signal-to-noise ratio (SNR) of the star spot could be improved, and extraction is achieved more effectively. Then, a prediction model for optimal estimation of the star spot position is obtained through the MEMS-gyro, and an extended Kalman filter is introduced. Meanwhile, the MEMS-gyro drift can be estimated and compensated though the proposed method. These enable the star tracker to achieve high star centroid determination accuracy under dynamic conditions. The MEMS-gyro drift can be corrected even when attitude data of the star tracker are unable to be solved and only one navigation star is captured in the field of view. Laboratory experiments were performed to verify the effectiveness of the proposed method and the whole system.

  3. In-flight star tracker SED 12 performances on-board the SIGMA experiment

    NASA Astrophysics Data System (ADS)

    Jouret, M.; Sebbag, I.; Vandermarcq, M. Q.; Krebs, J. P.; Le Goff, R.; Vilaire, D.; Tulet, M. M.

    The multimission SED 12 star tracker using a CCD matrix array has been designed by SODERN in cooperation with Matra-Marconi Space (F), respectively in charge of the optical head and software development for one and processing electronics and associated interfaces for the other. It has been selected for the French SIGMA experiment on board the Soviet GRANAT spacecraft which was launched on December 2, 1989. SIGMA is a French hard X-ray/medium energy gamma ray (30 keV-2 MeV) experiment aimed at imaging selected regions of the sky with a resolution of about one arc minute and has been developed and manufactured under the overall management of CNES (the French National Space Agency). The experiment package demands a pointing stability of a few arc-seconds over periods of several hours corresponding to the long exposure times required to build up images of the target gamma sources. As the GRANAT satellite is not able to maintain such high precision attitude stability, incorporated into the gamma telescope are two SED 12 sensors aligned together with the telescope. The development of this star tracker was started in 1985 under a CNES contract, the qualification was successfully performed in 1987 and the delivery of 2 flight models was completed in 1988. The expected life time of the experiment was 1.5 year and since the launch date the mission is still operating without any significant performance degradation of the star tracker. The purpose of this paper is, on the one hand to present the multimission tracker design trade-offs and the SED 12 device: description, main features, operating modes and performances, and on the other hand, to analyze the on ground and in-flight star tracker data. This analysis has been mainly led according to the following criteria: performance results in angular position and magnitude measurement, dark current evolution versus time and radiation dose, correlation between visual and instrumental magnitudes.

  4. Autonomous attitude estimation via star sensing and pattern recognition

    NASA Technical Reports Server (NTRS)

    Junkins, J. L.; Strikwerda, T. E.

    1979-01-01

    Results are reported on the development of an autonomous, onboard, near real time spacecraft attitude estimation technique. The approach uses CCD based star sensors to digitize relative star positions. Three microcomputers are envisioned, configured in parallel, to: (1) determine star image centroids and delete spurious images; (2) identify measured stars with stars in an onboard catalog and determine discrete attitude estimates; (3) integrate gyro rate measurements and determine optimal real time attitude estimates for use in the control system and for feedback to the star identification algorithm. Algorithms for the star identification are presented. The discrete attitude estimation algorithm recovers thermally varying interlock angles between two star sensors. The optimal state estimation process recovers rate gyro biases in addition to real time attitude estimates.

  5. Performance of the Star Tracker Lightshades on the Earth Observing Satellite (EOS) Aqua

    NASA Technical Reports Server (NTRS)

    Kenney, Thomas; Schroeder, Michael; Donnelly, Michael; McNally, Mark; Bauer, Frank H. (Technical Monitor)

    2003-01-01

    The TRW built EOS Aqua spacecraft uses two Ball Aerospace CT-602 star trackers to provide attitude updates to the 3-axis, zero momentum, controller. Two months prior to the scheduled launch of Aqua, Ball reported an error in the design of the star tracker lightshades. The lightshades, which had been designed specifically for the EOS Common spacecraft, were not expected to meet the stray light rejection requirements of the mission and thus impact the overall spacecraft pointing performance. What ensued was an effort to characterize the actual performance of the existing shade design, determine what could be done within the physical envelope available, and modify the hardware to meet requirements. Changes were made based on this review activity and Aqua was launched on May 4, 2002. To date the spacecraft is meeting all of its science pointing requirements. Reported here are the lightshade design predictions, test results, and the measured on orbit performance of these shades.

  6. Performance of the Star Tracker Lightshades on the Earth Observing Satellite (EOS) Aqua

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas; Lee, Albert; Donnelly, Michael; Schroder, Michael; McNally, Mark

    2003-01-01

    The TRW built EOS Aqua spacecraft uses two Ball Aerospace CT-602 star trackers to provide attitude updates to the 3-axis, zero momentum, controller. Two months prior to the scheduled launch of Aqua, Ball reported an error in the design of the star tracker lightshades. The lightshades, which had been designed specifically for the EOS Common spacecraft, were not expected to meet the stray light rejection requirements of the mission, thus impacting the overall spacecraft pointing performance. What ensued was an effort to characterize the actual performance of the existing shade design, determine what could be done within the physical envelope available, and modify the hardware to meet requirements. Changes were made based on this review activity and Aqua was launched on May 4, 2002. To date the spacecraft is meeting all of its science pointing requirements. Reported here are the lightshade design predictions, test results, and the measured on orbit performance of these shades.

  7. Apollo Telescope Mount (ATM) gimballed star tracker. [developed for the Skylab program

    NASA Technical Reports Server (NTRS)

    Lana, J. D.

    1974-01-01

    Design and development of six gimballed star trackers for Skylab's Apollo Telescope Mount, which performed successfully on all three manned Skylab missions and accumulated a total usage time of approximately 3,500 hours, is described in terms of configurations, materials and construction, qualification testing, performance, and reliability characteristics. A brief program history and design changes incorporated during the life of the program are also discussed. Extensive drawings, block diagrams, and photographs are provided.

  8. Optical analysis of the star-tracker telescope for Gravity Probe

    NASA Technical Reports Server (NTRS)

    Zissa, D. E.

    1984-01-01

    A ray tracing modeling of the star tracker telescope for Gravity Probe was used to predict the character of the output signal and its sensitivity to fabrication errors. In particular, the impact of the optical subsystem on the requirement of 1 milliarc second signal linearity over a + or - 50 milliarc second range was examined. Photomultiplier and solid state detector options were considered. Recommendations are made.

  9. Reducing Systematic Centroid Errors Induced by Fiber Optic Faceplates in Intensified High-Accuracy Star Trackers

    PubMed Central

    Xiong, Kun; Jiang, Jie

    2015-01-01

    Compared with traditional star trackers, intensified high-accuracy star trackers equipped with an image intensifier exhibit overwhelmingly superior dynamic performance. However, the multiple-fiber-optic faceplate structure in the image intensifier complicates the optoelectronic detecting system of star trackers and may cause considerable systematic centroid errors and poor attitude accuracy. All the sources of systematic centroid errors related to fiber optic faceplates (FOFPs) throughout the detection process of the optoelectronic system were analyzed. Based on the general expression of the systematic centroid error deduced in the frequency domain and the FOFP modulation transfer function, an accurate expression that described the systematic centroid error of FOFPs was obtained. Furthermore, reduction of the systematic error between the optical lens and the input FOFP of the intensifier, the one among multiple FOFPs and the one between the output FOFP of the intensifier and the imaging chip of the detecting system were discussed. Two important parametric constraints were acquired from the analysis. The correctness of the analysis on the optoelectronic detecting system was demonstrated through simulation and experiment. PMID:26016920

  10. Reducing systematic centroid errors induced by fiber optic faceplates in intensified high-accuracy star trackers.

    PubMed

    Xiong, Kun; Jiang, Jie

    2015-01-01

    Compared with traditional star trackers, intensified high-accuracy star trackers equipped with an image intensifier exhibit overwhelmingly superior dynamic performance. However, the multiple-fiber-optic faceplate structure in the image intensifier complicates the optoelectronic detecting system of star trackers and may cause considerable systematic centroid errors and poor attitude accuracy. All the sources of systematic centroid errors related to fiber optic faceplates (FOFPs) throughout the detection process of the optoelectronic system were analyzed. Based on the general expression of the systematic centroid error deduced in the frequency domain and the FOFP modulation transfer function, an accurate expression that described the systematic centroid error of FOFPs was obtained. Furthermore, reduction of the systematic error between the optical lens and the input FOFP of the intensifier, the one among multiple FOFPs and the one between the output FOFP of the intensifier and the imaging chip of the detecting system were discussed. Two important parametric constraints were acquired from the analysis. The correctness of the analysis on the optoelectronic detecting system was demonstrated through simulation and experiment. PMID:26016920

  11. Fixed-head star tracker attitude updates on the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Nadelman, Matthew S.; Karl, Jeffrey B.; Hallock, Lou

    1994-01-01

    The Hubble Space Telescope (HST) was launched in April 1990 to begin observing celestial space to the edge of the universe. National Aeronautics and Space Administration (NASA) standard fixed-head star trackers (FHST's) are used operationally onboard the HST to regularly adjust ('update') the spacecraft attitude before the acquisition of guide stars for science observations. During the first 3 months of the mission, the FHST's updated the spacecraft attitude successfully only 85 percent of the time. During the other periods, the trackers were unable to find the selected stars -- either they failed to find any star, or worse, they selected incorrect stars and produced erroneous attitude updates. In July 1990, the HST project office at Goddard Space Flight Center (GSFC) requested that Computer Sciences Corporation (CSC) form an investigative 'tiger' team to examine these FHST update failures. This paper discusses the work of the FHST tiger team, describes the investigations that led the team to identify the sources of the errors, and defines the solutions that were subsequently developed, which ultimately increased the success rate of FHST updates to approximately 98 percent.

  12. (abstract) Realization of a Faster, Cheaper, Better Mission and Its New Paradigm Star Tracker, the Advanced Stellar Compass

    NASA Technical Reports Server (NTRS)

    Eisenman, Allan Read; Liebe, Carl Christian; Joergensen, John Lief; Jensen, Gunnar Bent

    1997-01-01

    The first Danish satellite, rsted, will be launched in August of 1997. The scientific objective of sted is to perform a precision mapping of the Earth's magnetic field. Attitude data for the payload and the satellite are provided by the Advanced Stellar Compass (ASC) star tracker. The ASC consists of a CCD star camera and a capable microprocessor which operates by comparing the star image frames taken by the camera to its internal star catalogs.

  13. Fixed-head star tracker magnitude calibration on the solar maximum mission

    NASA Technical Reports Server (NTRS)

    Pitone, Daniel S.; Twambly, B. J.; Eudell, A. H.; Roberts, D. A.

    1990-01-01

    The sensitivity of the fixed-head star trackers (FHSTs) on the Solar Maximum Mission (SMM) is defined as the accuracy of the electronic response to the magnitude of a star in the sensor field-of-view, which is measured as intensity in volts. To identify stars during attitude determination and control processes, a transformation equation is required to convert from star intensity in volts to units of magnitude and vice versa. To maintain high accuracy standards, this transformation is calibrated frequently. A sensitivity index is defined as the observed intensity in volts divided by the predicted intensity in volts; thus, the sensitivity index is a measure of the accuracy of the calibration. Using the sensitivity index, analysis is presented that compares the strengths and weaknesses of two possible transformation equations. The effect on the transformation equations of variables, such as position in the sensor field-of-view, star color, and star magnitude, is investigated. In addition, results are given that evaluate the aging process of each sensor. The results in this work can be used by future missions as an aid to employing data from star cameras as effectively as possible.

  14. A high-accuracy digital star tracker for advanced planetary missions.

    NASA Technical Reports Server (NTRS)

    Salomon, P. M.; Crawford, W. E.

    1972-01-01

    The digital star tracker represents a novel departure from previous analog designs in terms of circuit implementation and operational capabilities. As an element of an all-digital spacecraft control system, it combines proven low-level analog signal processing with digital error control and command functions. Additional capabilities that are obtainable with the digital circuitry include programmable intensity threshold gates, commanded electronic pointing control, and an acquisition/control algorithm which minimizes the effects of straylight disturbances. The capabilities inherent in the implementation have been successfully demonstrated in a laboratory model of the instrument.

  15. A high-accuracy digital star tracker for advanced planetary missions

    NASA Technical Reports Server (NTRS)

    Salomon, P. M.; Crawford, W. E.

    1973-01-01

    The digital star tracker represents a novel departure from previous analog designs in terms of circuit implementation and operational capabilities. As an element of an all-digital spacecraft control system, it combines proven low-level analog signal processing with digital error control and command functions. Additional capabilities that are obtainable with the digital circuitry include programmable intensity threshold gates, commanded electronic pointing control, and an acquisition/control algorithm which minimizes the effects of straylight disturbances. The capabilities inherent in the implementation have been successfully demonstrated in a laboratory model of the instrument.

  16. Theoretic Studies of Full Constraints on a Star Tracker's Influential Error Sources for In-orbit Calibration

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Cai Hao, Yun; Wang, Li; Long, Ye

    2016-03-01

    To collect star transits data qualified for in-orbit calibration, this study derives the full error constraints to limit star tracker's influential error sources and computes their error boundaries from a theoretical perspective. The full constraints, including not only the minimum variance estimation of position but also the error bound prediction of scale and intensity of Gaussian-shaped starspots, are studied based on the Cramér-Rao Lower Bound (CRLB) theorem. By imposing these constraints on motion, drift in focal length, and other factors, their boundaries could be determined before launch. Therefore, the in-orbit correction accuracy is expected to be close to CRLB through suitable implementation of these constraints. The correctness of the theoretical position error of motion is demonstrated by the data-fitting procedure against test results of star tracker on dynamic performance. The simulation result shows that the drift in focal length can generate an error with the same magnitude as detector noise and thus might be the dominant error source when star tracker is working under stationary circumstance. Using the accuracy performance of some typical star trackers, this study shows that the CRLB constraint may be very effective to estimate the overall position error of a starspot or one axis, valuable data that can be used for online calibration. The overall position uncertainty analysis shows that a weighted method can be employed for calibration, a process where star data can be given a weight in inverse proportion to the CRLB value.

  17. Color/magnitude calibration for National Aeronautics and Space Administration (NASA) standard Fixed-Head Star Trackers (FHST)

    NASA Technical Reports Server (NTRS)

    Landis, J.; Leid, Terry; Garber, A.; Lee, M.

    1994-01-01

    This paper characterizes and analyzes the spectral response of Ball Aerospace fixed-head star trackers, (FHST's) currently in use on some three-axis stabilized spacecraft. The FHST output is a function of the frequency and intensity of the incident light and the position of the star image in the field of view. The FHST's on board the Extreme Ultraviolet Explorer (EUVE) have had occasional problems identifying stars with a high B-V value. These problems are characterized by inaccurate intensity counts observed by the tracker. The inaccuracies are due to errors in the observed star magnitude values. These errors are unique to each individual FHST. For this reason, data were also collected and analyzed from the Upper Atmosphere Research Satellite (UARS). As a consequence of this work, the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) hopes to improve the attitude accuracy on these missions and to adopt better star selection procedures for catalogs.

  18. Fast and robust pointing and tracking using a second-generation star tracker

    NASA Astrophysics Data System (ADS)

    Joergensen, John L.; Pickles, Andrew J.

    1998-05-01

    Second generation star trackers work by taking wide-angle optical pictures of star fields, correlating the image against a star catalogue in ROM, centroiding many stars to derive an accurate position and orientation. This paper describes a miniature instrument, fast and lightweight, including database and search engine. It can be attached to any telescope to deliver an accurate absolute attitude reference via a serial line. It is independent of encoders or control system, and works whenever it can see the sky. Position update rates in the range of 1 to 5 Hz enable closed-loop operations. The paper describes the instrument operational principles, and its application as an attitude reference unit for a telescope. Actual data obtained at the University of Hawaii's 0.6-m telescope are presented, and their utility for correcting mechanical alignment discussed. The system has great potential as a positioner and guider for (i) remotely operated optical telescopes, (ii) IR telescopes operating in dark clouds, and (iii) radio telescopes. Other application recommendations and the performance estimates are given.

  19. Studies on dynamic motion compensation and positioning accuracy on star tracker.

    PubMed

    Jun, Zhang; Yuncai, Hao; Li, Wang; Da, Liu

    2015-10-01

    Error from motion is the dominant restriction on the improvement of dynamic performance on a star tracker. As a remarkable motion error, the degree of nonuniformity of the star image velocity field on the detector is studied, and thus a general model for the moving star spot is built. To minimize velocity nonuniformity, a novel general method is proposed to derive the proper motion compensation and location accuracy in cases of both uniform velocity and acceleration. Using this method, a theoretic analysis on the accuracy of time-delayed integration and similar techniques, which are thought of as state-of-the-art approaches to reduce error from motion, is conducted. The simulations and experimental results validate the proposed method. Our method shows a more steady performance than the dynamic binning algorithm. The positional error could be neglected when the smear length is far less than 3.464 times the scale of star spot, which suggests accuracy can be maintained by changing frame-integration time inverse proportional to the velocity on the focal plane. It also shows that the acceleration effect must be compensated to achieve accuracy close to the Cramér-Rao lower bound. PMID:26479618

  20. An Autonomous Star Identification Algorithm Based on One-Dimensional Vector Pattern for Star Sensors.

    PubMed

    Luo, Liyan; Xu, Luping; Zhang, Hua

    2015-01-01

    In order to enhance the robustness and accelerate the recognition speed of star identification, an autonomous star identification algorithm for star sensors is proposed based on the one-dimensional vector pattern (one_DVP). In the proposed algorithm, the space geometry information of the observed stars is used to form the one-dimensional vector pattern of the observed star. The one-dimensional vector pattern of the same observed star remains unchanged when the stellar image rotates, so the problem of star identification is simplified as the comparison of the two feature vectors. The one-dimensional vector pattern is adopted to build the feature vector of the star pattern, which makes it possible to identify the observed stars robustly. The characteristics of the feature vector and the proposed search strategy for the matching pattern make it possible to achieve the recognition result as quickly as possible. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition accuracy and robustness by the proposed algorithm are better than those by the pyramid algorithm, the modified grid algorithm, and the LPT algorithm. The theoretical analysis and experimental results show that the proposed algorithm outperforms the other three star identification algorithms. PMID:26198233

  1. An Autonomous Star Identification Algorithm Based on One-Dimensional Vector Pattern for Star Sensors

    PubMed Central

    Luo, Liyan; Xu, Luping; Zhang, Hua

    2015-01-01

    In order to enhance the robustness and accelerate the recognition speed of star identification, an autonomous star identification algorithm for star sensors is proposed based on the one-dimensional vector pattern (one_DVP). In the proposed algorithm, the space geometry information of the observed stars is used to form the one-dimensional vector pattern of the observed star. The one-dimensional vector pattern of the same observed star remains unchanged when the stellar image rotates, so the problem of star identification is simplified as the comparison of the two feature vectors. The one-dimensional vector pattern is adopted to build the feature vector of the star pattern, which makes it possible to identify the observed stars robustly. The characteristics of the feature vector and the proposed search strategy for the matching pattern make it possible to achieve the recognition result as quickly as possible. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition accuracy and robustness by the proposed algorithm are better than those by the pyramid algorithm, the modified grid algorithm, and the LPT algorithm. The theoretical analysis and experimental results show that the proposed algorithm outperforms the other three star identification algorithms. PMID:26198233

  2. Analysis for Mar Vel Black and acetylene soot low reflectivity surfaces for star tracker sunshade applications

    NASA Technical Reports Server (NTRS)

    Yung, E.

    1974-01-01

    Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A sample of Mar Vel Black was evaluated. Mar Vel Black looks much like a super black surface with many small peaks and very steep sides so that any light incident upon the surface will tend to reflect many times before exiting that surface. Even a high reflectivity surface would thus appear to have a very low reflectivity under such conditions. Conversely, acetylene soot does not have the magnified surface appearance of a super black surface. Its performance is, however, predictable from the surface structure, considering the known configuration of virtually pure carbon.

  3. Test of charge injection device, phase 1. [prospective star tracker application

    NASA Technical Reports Server (NTRS)

    Gradinger, A.; Sayles, M. B.; Peters, D.; Buckley, P.

    1981-01-01

    A computer-controlled automatic facility containing two interactive microprocessors, peripherals, and an optical bench was used to obtain device characteristics for use in evaluating CID's as the sensor element in a prospective star tracker application. Each of the ST-256 chips tested contains a 256 x 256 pixel element array with 65536 picture elements. Two ST-256 devices were tested at 20 C under light levels of 10%, 0.1%, and 0.01% saturation, and in darkness. The saturation level was established at 0.95 microwatts sq cm as measured by the radiometeric sensor. Two test runs under each condition were performed for each chip. Two complete sets of data for each of the devices were thus obtained. A separate data field was used to store the results of each test condition. Repetitive runs of a test condition were stored sequentially in the same file. Examination of the data using print-outs is shown in examples.

  4. A study of a multi-pinned phase CCD detector for use as a star tracker

    NASA Technical Reports Server (NTRS)

    Friedman, Scott D.

    1994-01-01

    This grant has supported studies of the use of charge coupled devices (CCD's) in star trackers in a number of different areas. Among the tasks we have pursued are the following: (1) radiation modeling and the increase in noise equivalent angle as a result of exposure to protons and bremsstrahlung gamma rays; (2) the development of pattern matching software to identify field locations from a CCD image and a pre-existing map of the local area; (3) observations of various stellar fields from the 24 inch telescope at the Offit Observatory at JHU, primarily to test the pattern matching software (these included crowded fields as well as moving objects, like comets); and (4) tracking of very faint objects to determine the faint limit of the CCD system.

  5. Star tracker constraint violations digital capability description and analysis results. Mission planning, mission analysis, and software formulation

    NASA Technical Reports Server (NTRS)

    Poston, P. L.

    1975-01-01

    Results of star tracker constraint violation analyses performed with the digital computer program Shuttle Attitude and Pointing Time Line Processor (SAPT) are presented. Results are typical of those utilized to provide the information required to update Baseline Reference Mission Attitude and Pointing Time Lines. Descriptions of SAPT modifications implemented to perform these analyses are also presented.

  6. Search for a high-altitude lunar dust exosphere using Clementine navigational star tracker measurements

    NASA Astrophysics Data System (ADS)

    Glenar, David A.; Stubbs, Timothy J.; Hahn, Joseph M.; Wang, Yongli

    2014-12-01

    During the 1994 Clementine lunar mapping mission, portions of 25 orbits were dedicated to a search for lunar horizon glow (LHG) using the spacecraft star tracker navigation cameras. Previous putative detections of LHG were believed to result from forward scattering of sunlight by exospheric dust grains with radii ≈ 0.1 µm, observable above the limb from within the shadow of the Moon near orbital sunrise or sunset. We have examined star tracker image sequences from five Clementine orbits in which the limb occulted the Sun, and was at least partially shadowed from earthshine, minimizing the chance of stray light contamination. No LHG appears in the image data, or in any of the net brightness images, after subtraction of a reference zodiacal light model. However, some of the images display faint excess limb brightness that appears to be solar streamer structure. Therefore, we derive upper limits for the amount of dust in the lunar exosphere that could be hidden by these brightness fluctuations using a dust-scattering simulation code and simple exponential dust profiles defined by surface concentration n0 and scale height H. Simulations using grains of radius 0.1 µm show that fluctuations in the observed excess brightness can be matched by a dust exosphere with a vertical column abundance n0H of 5-30 cm-2 and overlying mass <10-12 g cm-2. These dust upper limit estimates are highly dependent on assumed grain size due to the rapid increase in per-grain brightness with grain radius.

  7. XpertTrack: Precision Autonomous Measuring Device Developed for Real Time Shipments Tracker.

    PubMed

    Viman, Liviu; Daraban, Mihai; Fizesan, Raul; Iuonas, Mircea

    2016-01-01

    This paper proposes a software and hardware solution for real time condition monitoring applications. The proposed device, called XpertTrack, exchanges data through the GPRS protocol over a GSM network and monitories temperature and vibrations of critical merchandise during commercial shipments anywhere on the globe. Another feature of this real time tracker is to provide GPS and GSM positioning with a precision of 10 m or less. In order to interpret the condition of the merchandise, the data acquisition, analysis and visualization are done with 0.1 °C accuracy for the temperature sensor, and 10 levels of shock sensitivity for the acceleration sensor. In addition to this, the architecture allows increasing the number and the types of sensors, so that companies can use this flexible solution to monitor a large percentage of their fleet. PMID:26978360

  8. XpertTrack: Precision Autonomous Measuring Device Developed for Real Time Shipments Tracker

    PubMed Central

    Viman, Liviu; Daraban, Mihai; Fizesan, Raul; Iuonas, Mircea

    2016-01-01

    This paper proposes a software and hardware solution for real time condition monitoring applications. The proposed device, called XpertTrack, exchanges data through the GPRS protocol over a GSM network and monitories temperature and vibrations of critical merchandise during commercial shipments anywhere on the globe. Another feature of this real time tracker is to provide GPS and GSM positioning with a precision of 10 m or less. In order to interpret the condition of the merchandise, the data acquisition, analysis and visualization are done with 0.1 °C accuracy for the temperature sensor, and 10 levels of shock sensitivity for the acceleration sensor. In addition to this, the architecture allows increasing the number and the types of sensors, so that companies can use this flexible solution to monitor a large percentage of their fleet. PMID:26978360

  9. Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

    NASA Technical Reports Server (NTRS)

    Orfiz, Gerardo G.; Lee, Shinhak

    2006-01-01

    A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

  10. Searching for Lunar Horizon Glow with the LRO Star Tracker Cameras

    NASA Astrophysics Data System (ADS)

    Stubbs, T. J.; Wang, Y.; Glenar, D. A.; McClanahan, T. P.; Myers, D. C.; Keller, J. W.

    2015-12-01

    Apollo-era observations of "lunar horizon glow" phenomena have been interpreted as being due to the forward scattering of sunlight by very small dust grains above the lunar surface. High altitude lunar horizon glow (LHG) seen in coronal photographs taken above orbital sunset during Apollo 15 is consistent with a population of exospheric dust grains with radii of ≈0.1 μm extending to altitudes of ≈10 km; while near-surface LHG observed by the TV cameras aboard a few of the Surveyor landers is consistent with dust grains with radii of ≈5 μm within about a meter of the surface. More recent searches have been undertaken for high altitude LHG, or the associated dust population, using the Clementine star tracker cameras (sensitive to visible and near-IR), the Lyman Alpha Mapping Project (LAMP) far-UV spectrograph on the Lunar Reconnaissance Orbiter (LRO), and the Lunar Dust Experiment (LDEX) on the Lunar Atmosphere and Dust Environment Explorer (LADEE). These searches have only produced upper limits for these exospheric dust abundances, as opposed to a clear detection. This motivated a search for LHG with the LRO star tracker cameras. Despite being designed for spacecraft navigation, the images these cameras produce are very suitable for scientific use. They also offer benefits over instruments previously used in terms of spatial resolution and ability to probe to low altitudes (both are of order a few hundred meters at the limb), as well as sensitivity to a similar wavelength range as the Apollo-era observations. Interestingly, the initial series of searches have resulted in some images that show bright patches at the limb that could be possible evidence for LHG. However, since these patches appear to typically extend only ~1000 m horizontally and just a few hundred meters vertically, this raises the possibility that they are simply due to sunlight reflected off surface topography along the limb. Initial simulations using a 64 pixel/degree digital elevation

  11. An enhanced Cramér-Rao bound weighted method for attitude accuracy improvement of a star tracker

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Wang, Jian

    2016-06-01

    This study presents a non-average weighted method for the QUEST (QUaternion ESTimator) algorithm, using the inverse value of root sum square of Cramér-Rao bound and focal length drift errors of the tracking star as weight, to enhance the pointing accuracy of a star tracker. In this technique, the stars that are brighter, or at low angular rate, or located towards the center of star field will be given a higher weight in the attitude determination process, and thus, the accuracy is readily improved. Simulations and ground test results demonstrate that, compared to the average weighted method, it can reduce the attitude uncertainty by 10%-20%, which is confirmed particularly for the sky zones with non-uniform distribution of stars. Moreover, by using the iteratively weighted center of gravity algorithm as the newly centroiding method for the QUEST algorithm, the current attitude uncertainty can be further reduced to 44% with a negligible additional computing load.

  12. The Study and Applications of Satellite and Satellite Constellation Autonomous Orbit Determination Using Star Sensor

    NASA Astrophysics Data System (ADS)

    Gan, Q. B.

    2012-07-01

    Autonomous satellite orbit determination is a key technique in autonomous satellite navigation. Many kinds of technologies have been proposed to realize the autonomous satellite navigation, such as the star sensor, the Earth magnetometer, the occultation time survey, and the phase measurement of X-ray pulsar signals. This dissertation studies a method of autonomous satellite orbit determination using star sensor. Moreover, the method is extended to the autonomous navigation of satellite constellation and the space-based surveillance. In chapters 1 and 2, some usual time and reference systems are introduced. Then the principles of several typical autonomous navigation methods, and their merits and shortcomings are analyzed. In chapter 3, the autonomous satellite orbit determination using star sensor and infrared Earth sensor (IRES) is specifically studied, which is based on the status movement simulation, the stellar background observation from star sensor, and the Earth center direction survey from IRES. By simulating the low Earth orbit satellites and pseudo Geostationary Earth orbit (PGEO) satellites, the precision of position and speed with autonomous orbit determination using star sensor is obtained. Besides, the autonomous orbit determination using star sensor with double detectors is studied. According to the observation equation's characters, an optimized type of star sensor and IRES initial assembly model is proposed. In the study of the PGEO autonomous orbit determination, an efficient sampling frequency of measurements is promoted. The simulation results confirm that the autonomous satellite orbit determination using star sensor is feasible for satellites with all kinds of altitudes. In chapter 4, the method of autonomous satellite orbit determination using star sensor is extended to the autonomous navigation of mini-satellite constellation. Combining with the high-accuracy inter satellite links data, the precision of the determined orbit and

  13. Heavy Flavor Physics in Heavy-Ion Collisions with STAR Heavy Flavor Tracker

    NASA Astrophysics Data System (ADS)

    Zhang, Yifei

    2010-02-01

    Heavy quarks are a unique tool to probe the strongly interacting matter created in relativistic heavy-ion collisions at RHIC energies. Due to their large mass, energetic heavy quarks are predicted to lose less energy than light quarks by gluon radiation when they traverse a Quark-Gluon Plasma. In contrast, recent measurements of non-photonic electrons from heavy quark decays at high transverse momentum (pT) show a jet quenching level similar to that of the light hadrons. Heavy quark are produced mainly at early stage in heavy-ion collisions, thus they are proposed to probe the QCD medium and to be sensitive to bulk medium properties. Ultimately, their flow behavior may help establish whether light quarks thermalize. Therefore, topological reconstruction of D-mesons and identification of electrons from charm and bottom decays are crucial to understand the heavy flavor production and their in medium properties. The Heavy Flavor Tracker (HFT) is a micro-vertex detector utilizing active pixel sensors and silicon strip technology. The HFT will significantly extend the physics reach of the STAR experiment for precise measurement of charmed and bottom hadrons. We present a performance study with full detector on the open charm nuclear modification factor, elliptic flow v2 and λc measurement as well as the measurement of bottom mesons via a semi-leptonic decay. )

  14. Calibration of the Heavy Flavor Tracker (HFT) detector in star experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Alanazi, Norah

    This project is in the area of Relativistic Nuclear collisions and the commissioning of a new silicon vertex detector, the Heavy Flavor Tracker (HFT) in the STAR experiment at Brookhaven National Laboratory (BNL). BNL hosts RHIC, the Relativistic Heavy Ion Collider, the world's most advanced dedicated heavy ion and polarized proton accelerator facility. Heavy Ion collisions at RHIC provide a unique probe into the understanding of several aspects of the behavior of nuclear, i.e. strongly inter- acting, matter. Among the many insights that can be provided is the description of parton interaction inside the hot and dense medium produced in the early stages of a collision. It also allows us to search for evidence for a phase transition in nuclear matter, a phase where partons [quarks and gluons] can move freely over an extended volume. Production of heavy quarks in high-energy nuclear collisions at RHIC occurs mainly during the initial collisions where energetic gluon and quark interactions can create heavy quarks. Thus, heavy flavor provides an ideal probe in studying the hot and dense medium created in the early phases of high-energy nuclear collisions. A detailed study of heavy flavor is essential to better understand the parton dynamics and select among competing theoretical approaches, however, precise measurements of heavy flavor are difficult to obtain due to relatively low production rates and short lifetimes of heavy flavor hadrons. The combinatorial background in nuclear collisions makes the measurement of heavy flavor a challenging task. One approach to dramatically reduce the combinatorial background by several orders of magnitude is to separate the heavy-flavor hadron's decay vertex from the background. This is done with the help of high resolution vertex detectors. The Heavy Flavor Tracker upgrade for the STAR experiment, which made its debut during the year 2014 RHIC run (Run14), greatly improved the experiment's track pointing capabilities making STAR

  15. Phobos interior from librations determination using Doppler and star tracker measurements

    NASA Astrophysics Data System (ADS)

    Le Maistre, Sebastien; Rosenblatt, Pascal; Rambaux, Nicolas; Castillo-Rogez, Julie C.; Dehant, Veronique; Marty, Jean-Charles

    2013-09-01

    Numerical simulations have been performed to assess the precision that can be obtained on Phobos libration angles by using two types of data acquired by a probe landed on the Martian moon: (1) Direct-To-Earth (DTE) Doppler data and (2) Star-Tracker (ST) data. Compared to independent estimates, combination of DTE and ST data provides the more precise estimates of Phobos libration angles at the 10-3-10-5 degree level. Short period libration amplitudes are functions of the relative moments of inertia. Thus their determination would provide constraints on mass distributions inside Phobos. We show that the longitudinal libration amplitude at the orbital period, while being clearly distinct from the resonance period, is the most interesting signal for that purpose, because it leads to the best precision on (B-A)/C (10-5 after only 10 weeks of operation). Nevertheless, we showed that inferring the individual moments of inertia A, B and C with a precision sufficient (<1%) to distinguish the rotational behavior of an homogenous from that of an heterogenous body requires the determination of one of the degree-two gravity field coefficient at the percent level. In addition, we stress that ST and DTE data combination allows de-correlating librational motion from orbital motion since ST measurements are sensitive to the moon's rotation and do not depend on its ephemeris, whereas DTE Doppler data are sensitive to both motions as well as to Phobos' surface displacement due to the tides raised by Mars. Furthermore, the ephemeris of Phobos has to be known at the centimeter level to allow measuring the tidal surface displacement with enough precision to conclude on the nature of Phobos' interior (rubble pile versus monolithic) as one step toward constraining its origin and evolution.

  16. Galileo spacecraft autonomous attitude determination using a V-slit star scanner

    NASA Technical Reports Server (NTRS)

    Mobasser, Sohrab; Lin, Shuh-Ren

    1991-01-01

    The autonomous attitude determination system of Galileo spacecraft, consisting of a radiation hardened star scanner and a processing algorithm is presented. The algorithm applying to this system are the sequential star identification and attitude estimation. The star scanner model is reviewed in detail and the flight software parameters that must be updated frequently during flight, due to degradation of the scanner response and the star background change are identified.

  17. An Autonomous Navigation Algorithm for High Orbit Satellite Using Star Sensor and Ultraviolet Earth Sensor

    PubMed Central

    Baohua, Li; Wenjie, Lai; Yun, Chen; Zongming, Liu

    2013-01-01

    An autonomous navigation algorithm using the sensor that integrated the star sensor (FOV1) and ultraviolet earth sensor (FOV2) is presented. The star images are sampled by FOV1, and the ultraviolet earth images are sampled by the FOV2. The star identification algorithm and star tracking algorithm are executed at FOV1. Then, the optical axis direction of FOV1 at J2000.0 coordinate system is calculated. The ultraviolet image of earth is sampled by FOV2. The center vector of earth at FOV2 coordinate system is calculated with the coordinates of ultraviolet earth. The autonomous navigation data of satellite are calculated by integrated sensor with the optical axis direction of FOV1 and the center vector of earth from FOV2. The position accuracy of the autonomous navigation for satellite is improved from 1000 meters to 300 meters. And the velocity accuracy of the autonomous navigation for satellite is improved from 100 m/s to 20 m/s. At the same time, the period sine errors of the autonomous navigation for satellite are eliminated. The autonomous navigation for satellite with a sensor that integrated ultraviolet earth sensor and star sensor is well robust. PMID:24250261

  18. Single event and TREE latchup mitigation for a star tracker sensor: An innovative approach to system level latchup mitigation

    SciTech Connect

    Kimbrough, J.R.; Colella, N.J.; Davis, R.W.; Bruener, D.B.; Coakley, P.G.; Lutjens, S.W.; Mallon, C.E.

    1994-08-01

    Electronic packages designed for spacecraft should be fault-tolerant and operate without ground control intervention through extremes in the space radiation environment. If designed for military use, the electronics must survive and function in a nuclear radiation environment. This paper presents an innovative ``blink`` approach rather than the typical ``operate through`` approach to achieve system level latchup mitigation on a prototype star tracker camera. Included are circuit designs, flash x-ray test data, and heavy ion data demonstrating latchup mitigation protecting micro-electronics from current latchup and burnout due to Single Event Latchup (SEL) and Transient Radiation Effects on Electronics (TREE).

  19. An enhanced Cramér-Rao bound weighted method for attitude accuracy improvement of a star tracker.

    PubMed

    Zhang, Jun; Wang, Jian

    2016-06-01

    This study presents a non-average weighted method for the QUEST (QUaternion ESTimator) algorithm, using the inverse value of root sum square of Cramér-Rao bound and focal length drift errors of the tracking star as weight, to enhance the pointing accuracy of a star tracker. In this technique, the stars that are brighter, or at low angular rate, or located towards the center of star field will be given a higher weight in the attitude determination process, and thus, the accuracy is readily improved. Simulations and ground test results demonstrate that, compared to the average weighted method, it can reduce the attitude uncertainty by 10%-20%, which is confirmed particularly for the sky zones with non-uniform distribution of stars. Moreover, by using the iteratively weighted center of gravity algorithm as the newly centroiding method for the QUEST algorithm, the current attitude uncertainty can be further reduced to 44% with a negligible additional computing load. PMID:27370431

  20. In-flight calibration and performance evaluation of the fixed head star trackers for the solar maximum mission

    NASA Technical Reports Server (NTRS)

    Thompson, R. H.; Gambardella, P. J.

    1980-01-01

    The Solar Maximum Mission (SMM) spacecraft provides an excellent opportunity for evaluating attitude determination accuracies achievable with tracking instruments such as fixed head star trackers (FHSTs). As a part of its payload, SMM carries a highly accurate fine pointing Sun sensor (FPSS). The EPSS provides an independent check of the pitch and yaw parameters computed from observations of stars in the FHST field of view. A method to determine the alignment of the FHSTs relative to the FPSS using spacecraft data is applied. Two methods that were used to determine distortions in the 8 degree by 8 degree field of view of the FHSTs using spacecraft data are also presented. The attitude determination accuracy performance of the in flight calibrated FHSTs is evaluated.

  1. Contingency Operations during Failure of Inertial Attitude Acquisition Due to Star Tracker Blinding for Three-Axes-Stabilized Interplanetary Spacecraft

    NASA Technical Reports Server (NTRS)

    Keil, Joachim; Herfort, Ulrich

    2007-01-01

    The three interplanetary ESA missions Mars-Express, Rosetta and Venus-Express (launched 2003, 2004 and 2005 resp.) are three-axes stabilized spacecraft (s/c) that estimate their inertial attitude (i.e. the attitude of the s/c w.r.t. the inertial frame) using measurements from a redundant set of star trackers (STR). Each s/c is equipped with four reaction wheels, a reaction control system based on thrusters and a redundant set of ring laser gyroscopes (gyros). The STR h/w layout of the three s/c is identical whereas there is a difference in the star pattern recognition algorithm of Rosetta which uses five neighbouring stars around a central star instead of star triads. The Rosetta algorithm has been implemented to cope with the presence of false stars which are expected to be seen during operations around the comet. The attitude acquisition capability from lost in space is different also in terms of AOCMS: The survival mode of Rosetta which is entered upon STR failure is presented. The AOCMS of Mars- and Venus-Express manages temporary STR outages during sky occultation by the planet not even by using redundancy. Though, a blinding of both STR during cruise lasting for the order of days confronts the ground operators with the limits of the AOCMS design. The operations and analyses that have been planned and partially been performed to compensate for the outage of the STR are demonstrated for Mars-Express. The caution measures taken before Venus orbit insertion of Venus-Express are detailed.

  2. Star Identification Without Attitude Knowledge: Testing with X-Ray Timing Experiment Data

    NASA Technical Reports Server (NTRS)

    Ketchum, Eleanor

    1997-01-01

    As the budget for the scientific exploration of space shrinks, the need for more autonomous spacecraft increases. For a spacecraft with a star tracker, the ability to determinate attitude from a lost in space state autonomously requires the capability to identify the stars in the field of view of the tracker. Although there have been efforts to produce autonomous star trackers which perform this function internally, many programs cannot afford these sensors. The author previously presented a method for identifying stars without a priori attitude knowledge specifically targeted for onboard computers as it minimizes the necessary computer storage. The method has previously been tested with simulated data. This paper provides results of star identification without a priori attitude knowledge using flight data from two 8 by 8 degree charge coupled device star trackers onboard the X-Ray Timing Experiment.

  3. The measurement of hadronic observables with the solenoidal tracker at RHIC (STAR)

    SciTech Connect

    Bellwied, R.

    1995-07-15

    The authors describe the capabilities of the STAR detector at RHIC regarding the measurement of hadronic observables. Special emphasis will be given to the determination of event-by-event observables deduced from particle spectra for protons (p), kaons (K) and pions ({pi}). The authors show that based on the present status of the simulations STAR will be able to measure quantities such as , slope parameter, and particle ratios on an event-by-event basis. These parameters, in connection with charged particle multiplicities as a function of momentum and rapidity, may shed light on the occurance of a phase transition in ultrarelativistic heavy ion collisions.

  4. In-flight scale/distortion calibration of the Hubble Space Telescope fixed-head star trackers

    NASA Technical Reports Server (NTRS)

    Mccutcheon, R.; Boia, John J.; Gakenheimer, Martin F.; Hallock, L.; Kimmer, E.; Murphy, S.; Welter, Gary L.

    1994-01-01

    This paper describes an in-flight scale and distortion calibration procedure that has been developed for the Ball Aerospace Systems Division Fixed-Head Star Trackers (FHST's) used on the Hubble Space Telescope (HST). The FHST is a magnetically focused and deflected imaging sensor that is designed to track stars as faint as m(sub v) = 5.7 over an 8 degree by 8 degree field of view. Raw FHST position measurements are accurate to approximately 200 arcseconds, but this can be improved to 10-15 arcseconds by processing the raw measurements through calibration polynomials that correct for flat field, temperature intensity, and magnetic field effects. The coefficients for these polynomials were initially determined using ground test data. On HST the use of three FHST's is an integral part of the preliminary attitude update procedures required before the acquisition of guide stars for science observations. To this end, FHST-based attitude determination having single-axis errors no worse than 22 arcseconds (1 sigma) is required. In early 1991 it became evident that one of the HST FHST's was experiencing a significant change in its optical scale. By mid-1993 the size of this error had grown to a point that, if not corrected, it would correspond to a maximum position error on the order of 100 arcseconds. Subsequent investigations demonstrated that substantial, uncompensated cubic distortion effects had also developed, the maximum contribution to position errors from the cubic terms being on the order of 30 arcseconds. To ensure accurate FHST-based attitude updates, procedures have been developed to redetermine the FHST scale and distortion calibration coefficients based on in-flight data gathered during normal HST operations. These scale and distortion calibrations have proven very effective operationally, and procedures are in place to monitor FHST calibration changes on a continuing basis.

  5. A computer-aided telescope pointing system utilizing a video star tracker

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.; Lorell, K. R.; Swift, C. D.

    1975-01-01

    The Video Inertial Pointing (VIP) System developed to satisfy the acquisition and pointing requirements of astronomical telescopes is described. A unique feature of the system is the use of a single sensor to provide information for the generation of three axis pointing error signals and for a cathode ray tube (CRT) display of the star field. The pointing error signals are used to update the telescope's gyro stabilization and the CRT display is used by an operator to facilitate target acquisition and to aid in manual positioning of the telescope optical axis. A model of the system using a low light level vidicon built and flown on a balloon-borne infrared telescope is briefly described from a state of the art charge coupled device (CCD) sensor. The advanced system hardware is described and an analysis of the multi-star tracking and three axis error signal generation, along with an analysis and design of the gyro update filter, are presented. Results of a hybrid simulation are described in which the advanced VIP system hardware is driven by a digital simulation of the star field/CCD sensor and an analog simulation of the telescope and gyro stabilization dynamics.

  6. Experience from the in-flight calibration of the Extreme Ultraviolet Explorer (EUVE) and Upper Atmosphere Research Satellite (UARS) fixed head star trackers (FHSTs)

    NASA Technical Reports Server (NTRS)

    Lee, Michael

    1995-01-01

    Since the original post-launch calibration of the FHSTs (Fixed Head Star Trackers) on EUVE (Extreme Ultraviolet Explorer) and UARS (Upper Atmosphere Research Satellite), the Flight Dynamics task has continued to analyze the FHST performance. The algorithm used for inflight alignment of spacecraft sensors is described and the equations for the errors in the relative alignment for the simple 2 star tracker case are shown. Simulated data and real data are used to compute the covariance of the relative alignment errors. Several methods for correcting the alignment are compared and results analyzed. The specific problems seen on orbit with UARS and EUVE are then discussed. UARS has experienced anomalous tracker performance on an FHST resulting in continuous variation in apparent tracker alignment. On EUVE, the FHST residuals from the attitude determination algorithm showed a dependence on the direction of roll during survey mode. This dependence is traced back to time tagging errors and the original post launch alignment is found to be in error due to the impact of the time tagging errors on the alignment algorithm. The methods used by the FDF (Flight Dynamics Facility) to correct for these problems is described.

  7. Hubble Space Telescope Star Tracker ad Two-Gyro Control Law Design, Implementation, and On-Orbit Performance. Part 2

    NASA Technical Reports Server (NTRS)

    VanArsdall, John C.

    2005-01-01

    The Hubble Space Telescope (HST) normally requires three gyroscopes for three-axis rate control. The loss of the Space Shuttle Columbia on STS-107 resulted in the cancellation of a shuttle-based HST Servicing Mission 4. Therefore, HST must operate using the on-board hardware until an alternate means of servicing can be accomplished. The probability of gyro failure indicates that fewer than three gyros will be operable before any servicing mission can be performe& To mitigate this, and to extend the HST life expectancy, a rate estimation and control algorithm was developed that requires two gyros to measure rate about two axes, with the remaining axis rate estimated using one of three alternate sensors. Three-axis magnetometers (MSS) are used for coarse rate estimation during large maneuvers and during occultations of other sensors. Fixed-Head Star Trackers (FHSTs) are used for rate estimation during safe mode recovery and during transition to science operations. Fine rate estimation during science operations is performed using the Fine Guidance Sensors (FGSs). The FHST mode (T2G) relies on star vectors as measured by the FHSTs to estimate vehicle rate about the axis not measured by the gyros. Since the FHSTs were not designed to estimate body rate, this method involves a unique set of problems that had to be overcome in the final design, such as the effect of FHST break tracks and moving targets on rate estimation. The solutions to these problems, as well as a detailed description of the design and implementation of the rate estimation are presented Also included are the time domain and frequency domain analysis of the T2G control law. A high fidelity HST simulator (HSTSIM) was used to verify T2G performance prior to on-orbit use. Results of these simulations are also presented. Finally, analysis of actual T2G on-orbit test results is presented for design validation.

  8. A computer-aided telescope pointing system utilizing a video star tracker

    NASA Technical Reports Server (NTRS)

    Lorell, K. R.; Murphy, J. P.; Swift, C. D.

    1976-01-01

    The Video Inertial Pointing (VIP) System is being developed to satisfy the acquisition and pointing requirements of astronomical telescopes. VIP employs a single video sensor to generate three-axis pointing error signals and to provide inputs for a cathode ray tube (CRT) display of the star field. The pointing error signals update the telescope's gyro stabilization system. The CRT display facilitates target acquisition and positioning of the telescope by a remote operator. The present paper describes the analysis, simulation, and hardware development of a prototype, advanced VIP system. An early model of the system utilizing a silicon-intensified target vidicon camera has flown on a balloon-borne telescope and is briefly described. The advanced system, which can employ either a vidicon camera or a charge-coupled device video sensor, has been tested using an analog/digital hybrid simulation. The advanced VIP hardware is described, and the simulation results presented.

  9. The secure, transportable, autonomous reactor (STAR): a small proliferation-resistant reactor system for developing countries

    SciTech Connect

    Brown, N W; Hassberger, J A; Smith, C F

    1999-05-27

    The Secure, Transportable, Autonomous Reactor (STAR), is an integrated concept for a small, proliferation-resistant nuclear power system capable of meeting the growing power demands of many regions of the developing world. The STAR approach builds on earlier work investigating the features required for implementation of such a system. The STAR approach includes establishing overall system requirements, conducting research into issues common to four reactor concepts (gas, liquid metal, light water and molten salt), and defining and performing the down-selection to a preferred concept that will serve as the basis for continued development leading to an eventual prototype. The paper indicates that a number of unique and distinguishing innovations are needed to both meet the energy demands of most of the world's developing regions and address growing nuclear proliferation concerns. These technical innovations form much of the basis underlying the STAR concept and include: eliminating on-site refueling and fuel access; incorporating a systems approach to nuclear energy supply and infrastructure design, with all aspects of equipment life, fuel and waste cycles included; small unit size enabling transportability; replaceable standardized modular design; resilient and robust design concepts leading to large safety margins, high reliability and reduced maintenance; simplicity in operation with reliance on autonomous control and remote monitoring; and waste minimization and waste form optimization.

  10. Teaching Astronomy Using Tracker

    NASA Astrophysics Data System (ADS)

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas

    2013-03-01

    A recent paper in this journal1 presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses.2-4 Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In this paper we describe the use of Tracker in introductory astronomy to analyze a ``video'' consisting of a series of still images of star fields and sunspots. Because astronomy focuses on concepts unfamiliar to most students, the visualization that video analysis provides can be especially valuable.

  11. Results from a prototype MAPS sensor telescope and readout system with zero suppression for the heavy flavor tracker at STAR

    NASA Astrophysics Data System (ADS)

    Greiner, L.; Matis, H. S.; Ritter, H. G.; Rose, A.; Stezelberger, T.; Sun, X.; Szelezniak, M.; Thomas, J.; Vu, C.; Wieman, H.

    2008-05-01

    We describe a three Mimostar-2 Monolithic Active Pixel Sensor (MAPS) sensor telescope prototype with an accompanying readout system incorporating on-the-fly data sparsification. The system has been characterized and we report on the measured performance of the sensor telescope and readout system in beam tests conducted both at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) and in the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). This effort is part of the development and prototyping work that will lead to a vertex detector for the STAR experiment.

  12. Results from a Prototype MAPS Sensor Telescope and Readout Systemwith Zero Suppression for the Heavy Flavor Tracker at STAR

    SciTech Connect

    Greiner, Leo C.; Matis, Howard S.; Ritter, Hans G.; Rose, AndrewA.; Stezelberger, Thorsten; Sun, Xiangming; Szelezniak, Michal A.; Thomas, James H.; Vu, Chinh Q.; Wieman, Howard H.

    2008-02-11

    We describe a three Mimostar-2 Monolithic Active PixelSensor (MAPS) sensor telescope prototype with an accompanying readoutsystem incorporating on-the-fly data sparsification. The system has beencharacterized and we report on the measured performance of the sensortelescope and readout system in beam tests conducted both at the AdvancedLight Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) and inthe STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Thiseffort is part of the development and prototyping work that will lead toa vertex detector for the STAR experiment.

  13. Tracker Toolkit

    NASA Technical Reports Server (NTRS)

    Lewis, Steven J.; Palacios, David M.

    2013-01-01

    This software can track multiple moving objects within a video stream simultaneously, use visual features to aid in the tracking, and initiate tracks based on object detection in a subregion. A simple programmatic interface allows plugging into larger image chain modeling suites. It extracts unique visual features for aid in tracking and later analysis, and includes sub-functionality for extracting visual features about an object identified within an image frame. Tracker Toolkit utilizes a feature extraction algorithm to tag each object with metadata features about its size, shape, color, and movement. Its functionality is independent of the scale of objects within a scene. The only assumption made on the tracked objects is that they move. There are no constraints on size within the scene, shape, or type of movement. The Tracker Toolkit is also capable of following an arbitrary number of objects in the same scene, identifying and propagating the track of each object from frame to frame. Target objects may be specified for tracking beforehand, or may be dynamically discovered within a tripwire region. Initialization of the Tracker Toolkit algorithm includes two steps: Initializing the data structures for tracked target objects, including targets preselected for tracking; and initializing the tripwire region. If no tripwire region is desired, this step is skipped. The tripwire region is an area within the frames that is always checked for new objects, and all new objects discovered within the region will be tracked until lost (by leaving the frame, stopping, or blending in to the background).

  14. Eye tracker.

    PubMed

    Pruehsner, W; Enderle, J D

    1999-01-01

    A device that records saccadic eye movements, the Eye Tracker, is presented in this paper. The Eye Tracker utilizes infra-red technology mounted on fully adjustable goggles to follow eye movements targeted by either a goggles mounted HUD type display or a wall mounted light bank. Output from the goggles is remotely sent to a PC type computer, which leads to device portability. The goggles can also maintain output data in an internal memory for latter download. The user interface is Windows based with the output from the goggles represented as a trace map or plotted points. This output can also be saved or printed for future reference. The user interface can be used on any PC type computer. The device is designed with reference to standard ISO design methodology. Safety in design and final product usage has also been addressed with reference to standard ISO type procedures. Device accuracy is maintained by precise construction of the IR units in the goggles and tight control of cross talk between each IR device plus filtering of ambient light signals. Also, a reset feature is included to maintain equal baseline control. An automatic switching device is included in the goggles to allow the Eye Tracker to "warm up," assuring that equal IR power is delivered for each subject tested. The IR units in the goggles are also modular in case replacement is required. PMID:11143354

  15. Technology transfer: Imaging tracker to robotic controller

    NASA Technical Reports Server (NTRS)

    Otaguro, M. S.; Kesler, L. O.; Land, Ken; Erwin, Harry; Rhoades, Don

    1988-01-01

    The transformation of an imaging tracker to a robotic controller is described. A multimode tracker was developed for fire and forget missile systems. The tracker locks on to target images within an acquisition window using multiple image tracking algorithms to provide guidance commands to missile control systems. This basic tracker technology is used with the addition of a ranging algorithm based on sizing a cooperative target to perform autonomous guidance and control of a platform for an Advanced Development Project on automation and robotics. A ranging tracker is required to provide the positioning necessary for robotic control. A simple functional demonstration of the feasibility of this approach was performed and described. More realistic demonstrations are under way at NASA-JSC. In particular, this modified tracker, or robotic controller, will be used to autonomously guide the Man Maneuvering Unit (MMU) to targets such as disabled astronauts or tools as part of the EVA Retriever efforts. It will also be used to control the orbiter's Remote Manipulator Systems (RMS) in autonomous approach and positioning demonstrations. These efforts will also be discussed.

  16. STAR - H2 : the secure transportable autonomous reactor for hydrogen production and desalinization.

    SciTech Connect

    Wade, D.C.; Doctor, R.; Peddicord, K.L.

    2002-02-26

    The Secure Transportable Autonomous Reactor for Hydrogen production is a modular fast reactor intended for the mid 21st century energy market wherein electricity and hydrogen are employed as complementary energy carriers and nuclear energy contributes to sustainable energy supply based on full transuranic recycle in a passively safe, environmentally friendly and proliferation-resistant manner suitable for widespread worldwide deployment.

  17. An onboard star identification algorithm

    NASA Astrophysics Data System (ADS)

    Ha, Kong; Femiano, Michael

    The paper presents the autonomous Initial Stellar Acquisition (ISA) algorithm developed for the X-Ray Timing Explorer for prividing the attitude quaternion within the desired accuracy, based on the one-axis attitude knowledge (through the use of the Digital Sun Sensor, CCD Star Trackers, and the onboard star catalog, OSC). Mathematical analysis leads to an accurate measure of the performance of the algorithm as a function of various parameters, such as the probability of a tracked star being in the OSC, the sensor noise level, and the number of stars matched. It is shown that the simplicity, tractability, and robustness of the ISA algorithm, compared to a general three-axis attiude determination algorithm, make it a viable on-board solution.

  18. An onboard star identification algorithm

    NASA Technical Reports Server (NTRS)

    Ha, Kong; Femiano, Michael

    1993-01-01

    The paper presents the autonomous Initial Stellar Acquisition (ISA) algorithm developed for the X-Ray Timing Explorer for prividing the attitude quaternion within the desired accuracy, based on the one-axis attitude knowledge (through the use of the Digital Sun Sensor, CCD Star Trackers, and the onboard star catalog, OSC). Mathematical analysis leads to an accurate measure of the performance of the algorithm as a function of various parameters, such as the probability of a tracked star being in the OSC, the sensor noise level, and the number of stars matched. It is shown that the simplicity, tractability, and robustness of the ISA algorithm, compared to a general three-axis attiude determination algorithm, make it a viable on-board solution.

  19. Interacting Multiview Tracker.

    PubMed

    Yoon, Ju Hong; Yang, Ming-Hsuan; Yoon, Kuk-Jin

    2016-05-01

    A robust algorithm is proposed for tracking a target object in dynamic conditions including motion blurs, illumination changes, pose variations, and occlusions. To cope with these challenging factors, multiple trackers based on different feature representations are integrated within a probabilistic framework. Each view of the proposed multiview (multi-channel) feature learning algorithm is concerned with one particular feature representation of a target object from which a tracker is developed with different levels of reliability. With the multiple trackers, the proposed algorithm exploits tracker interaction and selection for robust tracking performance. In the tracker interaction, a transition probability matrix is used to estimate dependencies between trackers. Multiple trackers communicate with each other by sharing information of sample distributions. The tracker selection process determines the most reliable tracker with the highest probability. To account for object appearance changes, the transition probability matrix and tracker probability are updated in a recursive Bayesian framework by reflecting the tracker reliability measured by a robust tracker likelihood function that learns to account for both transient and stable appearance changes. Experimental results on benchmark datasets demonstrate that the proposed interacting multiview algorithm performs robustly and favorably against state-of-the-art methods in terms of several quantitative metrics. PMID:26336117

  20. STAR: The Secure Transportable Autonomous Reactor System - Encapsulated Fission Heat Source

    SciTech Connect

    Ehud Greenspan

    2003-10-31

    OAK-B135 The Encapsulated Nuclear Heat Source (ENHS) is a novel 125 MWth fast spectrum reactor concept that was selected by the 1999 DOE NERI program as a candidate ''Generation-IV'' reactor. It uses Pb-Bi or other liquid-metal coolant and is intended to be factory manufactured in large numbers to be economically competitive. It is anticipated to be most useful to developing countries. The US team studying the feasibility of the ENHS reactor concept consisted of the University of California, Berkeley, Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL) and Westinghouse. Collaborating with the US team were three Korean organizations: Korean Atomic Energy Research Institute (KAERI), Korean Advanced Institute for Science and Technology (KAIST) and the University of Seoul, as well as the Central Research Institute of the Electrical Power Industry (CRIEPI) of Japan. Unique features of the ENHS include at least 20 years of operation without refueling; no fuel handling in the host country; no pumps and valves; excess reactivity does not exceed 1$; fully passive removal of the decay heat; very small probability of core damaging accidents; autonomous operation and capability of load-following over a wide range; very long plant life. In addition it offers a close match between demand and supply, large tolerance to human errors, is likely to get public acceptance via demonstration of superb safety, lack of need for offsite response, and very good proliferation resistance. The ENHS reactor is designed to meet the requirements of Generation IV reactors including sustainable energy supply, low waste, high level of proliferation resistance, high level of safety and reliability, acceptable risk to capital and, hopefully, also competitive busbar cost of electricity.

  1. Development of a digital mobile solar tracker

    NASA Astrophysics Data System (ADS)

    Baidar, S.; Kille, N.; Ortega, I.; Sinreich, R.; Thomson, D.; Hannigan, J.; Volkamer, R.

    2015-11-01

    We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV-Vis and FTIR spectrometers making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun Differential Optical Absorption Spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Photochemistry and Pollution Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives, and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution, and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.

  2. Development of a digital mobile solar tracker

    NASA Astrophysics Data System (ADS)

    Baidar, Sunil; Kille, Natalie; Ortega, Ivan; Sinreich, Roman; Thomson, David; Hannigan, James; Volkamer, Rainer

    2016-03-01

    We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV-Vis and Fourier transform infrared spectrometers, making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun differential optical absorption spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.

  3. The development of a charge-coupled device tracker for spacecraft

    NASA Technical Reports Server (NTRS)

    Dennison, E. W.; Stanton, R. H.; Shimada, K.

    1987-01-01

    Charge-coupled device (CCD) optical sensors have made it possible to construct high performance star and target trackers for spacecraft. The Advanced Star and Target Reference Orbital Sensor (ASTROS) trackers have been developed by JPL for the Shuttle-based astronomical flight Astro-1 and the Mariner Mark II (MMII) spacecraft. For the Shuttle application the tracker will provide the data for high precision instrument pointing and for the MMII application the tracker will provide stellar and extended target tracking data for flyby and rendezvous navigation. The specifications, architecture, and testing program for these trackers will be described. Laboratory measurements have demonstrated that these trackers can be very effective. The versatility and flexibility of the ASTROS type trackers will permit adaptation to a variety of navigation and guidance applications. These trackers represent one of the technologically advanced components that will be used in the development of the next generation of spacecraft.

  4. The electromagnetic calorimeter for the solenoidal tracker at RHIC. A Conceptual Design Report

    SciTech Connect

    Beddo, M.E.; Bielick, E.; Dawson, J.W.; The STAR EMC Collaboration

    1993-09-22

    This report discusses the following on the electromagnetic calorimeter for the solenoidal tracker at RHIC: conceptual design; the physics of electromagnetic calorimetry in STAR; trigger capability; integration into STAR; and cost, schedule, manpower, and funding.

  5. ORNL SunTracker

    SciTech Connect

    Wysor, Robert Wesley

    2005-09-14

    The ORNL Sun Tracker software is the user interface that operates on a Personal Computer and serially communicates with the controller board. This software allows the user to manually operate the Hybrid Solar Lighting (HSL) unit. It displays the current location of the HSL unit, its parameters and it provides real-time monitoring. The ORNL Sun Tracker software is also the main component used in setting up and calibrating the tracker. It contains a setup screen that requires latitude, longitude, and a few other key values to accurately locate the sun's position. The software also will provide the user access to calibrate the tracking location in relation to the sun's actual position.

  6. Breadboard stellar tracker system test report, volume 1

    NASA Technical Reports Server (NTRS)

    Kollodge, J. C.; Hubbard, M. W.; Jain, S.; Schons, C. A.

    1981-01-01

    The performance of a star tracker equipped with a focal plane detector was evaluated. The CID board is an array of 256 x 256 pixels which are 20 x 20 micrometers in dimension. The tracker used for test was a breadboard tracker system developed by BASD. Unique acquisition and tracking algorithms are employed to enhance performance. A pattern recognition process is used to test for proper image spread function and to avoid false acquisition on noise. A very linear, high gain, interpixel transfer function is derived for interpolating star position. The lens used in the tracker has an EFL of 100 mm. The tracker has an FOV of 2.93 degrees resulting in a pixel angular subtense of 41.253 arc sec in each axis. The test procedure used for the program presented a star to the tracker in a circular pattern of positions; the pattern was formed by projecting a simulated star through a rotatable deviation wedge. Further tests determined readout noise, Noise Equivalent Displacement during track, and spatial noise during acquisition by taking related data and reducing it.

  7. Miniature Laser Tracker

    DOEpatents

    Vann, Charles S.

    2003-09-09

    This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

  8. Breadboard stellar tracker system test report, volume 2

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Complete data from a test program designed to evaluate the performance of a star tracker, a breadboard tracker system, is presented in tabular form. All data presented was normalized to the pixel dimension of 20 micrometers. Data from determination of maximum spatial noise as it applies to the coarse and fine acquisition modes is presented. Pointing accuracy test data, raw pixel data for the track cycle, and data from equipment related tests is also presented.

  9. ORNL SunTracker

    Energy Science and Technology Software Center (ESTSC)

    2005-09-14

    The ORNL Sun Tracker software is the user interface that operates on a Personal Computer and serially communicates with the controller board. This software allows the user to manually operate the Hybrid Solar Lighting (HSL) unit. It displays the current location of the HSL unit, its parameters and it provides real-time monitoring. The ORNL Sun Tracker software is also the main component used in setting up and calibrating the tracker. It contains a setup screenmore » that requires latitude, longitude, and a few other key values to accurately locate the sun's position. The software also will provide the user access to calibrate the tracking location in relation to the sun's actual position.« less

  10. Teaching Astronomy Using Tracker

    ERIC Educational Resources Information Center

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas

    2013-01-01

    A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

  11. Rotational Dynamics with Tracker

    ERIC Educational Resources Information Center

    Eadkhong, T.; Rajsadorn, R.; Jannual, P.; Danworaphong, S.

    2012-01-01

    We propose the use of Tracker, freeware for video analysis, to analyse the moment of inertia ("I") of a cylindrical plate. Three experiments are performed to validate the proposed method. The first experiment is dedicated to find the linear coefficient of rotational friction ("b") for our system. By omitting the effect of such friction, we derive…

  12. MediaTracker system

    SciTech Connect

    Sandoval, D. M.; Strittmatter, R. B.; Abeyta, J. D.; Brown, J.; Marks, T. , Jr.; Martinez, B. J.; Jones, D. B.; Hsue, W.

    2004-01-01

    The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access to the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can accommodate

  13. Semi-physical simulation test for micro CMOS star sensor

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Zhang, Guang-jun; Jiang, Jie; Fan, Qiao-yun

    2008-03-01

    A designed star sensor must be extensively tested before launching. Testing star sensor requires complicated process with much time and resources input. Even observing sky on the ground is a challenging and time-consuming job, requiring complicated and expensive equipments, suitable time and location, and prone to be interfered by weather. And moreover, not all stars distributed on the sky can be observed by this testing method. Semi-physical simulation in laboratory reduces the testing cost and helps to debug, analyze and evaluate the star sensor system while developing the model. The test system is composed of optical platform, star field simulator, star field simulator computer, star sensor and the central data processing computer. The test system simulates the starlight with high accuracy and good parallelism, and creates static or dynamic image in FOV (Field of View). The conditions of the test are close to observing real sky. With this system, the test of a micro star tracker designed by Beijing University of Aeronautics and Astronautics has been performed successfully. Some indices including full-sky autonomous star identification time, attitude update frequency and attitude precision etc. meet design requirement of the star sensor. Error source of the testing system is also analyzed. It is concluded that the testing system is cost-saving, efficient, and contributes to optimizing the embed arithmetic, shortening the development cycle and improving engineering design processes.

  14. The LHCb silicon tracker

    NASA Astrophysics Data System (ADS)

    Adeva, B.; Agari, M.; Bauer, C.; Baumeister, D.; Bay, A.; Bernhard, R. P.; Bernet, R.; Blouw, J.; Carron, B.; Ermoline, Y.; Esperante, D.; Frei, R.; Gassner, J.; Hofmann, W.; Jimenez-Otero, S.; Knöpfle, K. T.; Köstner, S.; Lehner, F.; Löchner, S.; Lois, C.; Needham, M.; Pugatch, V.; Schmelling, M.; Schwingenheuer, B.; Siegler, M.; Steinkamp, O.; Straumann, U.; Tran, M. T.; Vazquez, P.; Vollhardt, A.; Volyanskyy, D.; Voss, H.

    2005-07-01

    LHCb is a dedicated B-physics and CP-violation experiment for the Large Hadron Collider at CERN. Efficient track reconstruction and excellent trigger performances are essential in order to exploit fully its physics potential. Silicon strip detectors providing fast signal generation, high resolution and fine granularity are used for this purpose in the large area Trigger Tracker station in front of the spectrometer magnet and the LHCb Inner Tracker covering the area close to the beam pipe behind the magnet. Long read-out strips of up to 38 cm are used together with fast signal shaping adapted to the 25 ns LHC bunch crossing. The design of these tracking stations, the silicon sensor strip geometries and the latest test results are presented here.

  15. The Tevatron Chromaticity tracker

    SciTech Connect

    Tan, Cheng-Yang; /Fermilab

    2008-12-01

    The Tevatron chromaticity tracker (CT) has been successfully commissioned and is now operational. The basic idea behind the CT is that when the phase of the Tevatron RF is slowly modulated, the beam momentum is also modulated. This momentum modulation is coupled transversely via chromaticity to manifest as a phase modulation on the betatron tune. Thus by phase demodulating the betatron tune, the chromaticity can be recovered. However, for the phase demodulation to be successful, it is critical that the betatron tune be a coherent signal that can be easily picked up by a phase detector. This is easily done because the Tevatron has a phase locked loop (PLL) based tune tracker which coherently excites the beam at the betatron tune.

  16. Autonomous and Autonomic Swarms

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Truszkowski, Walter F.; Rouff, Christopher A.; Sterritt, Roy

    2005-01-01

    A watershed in systems engineering is represented by the advent of swarm-based systems that accomplish missions through cooperative action by a (large) group of autonomous individuals each having simple capabilities and no global knowledge of the group s objective. Such systems, with individuals capable of surviving in hostile environments, pose unprecedented challenges to system developers. Design and testing and verification at much higher levels will be required, together with the corresponding tools, to bring such systems to fruition. Concepts for possible future NASA space exploration missions include autonomous, autonomic swarms. Engineering swarm-based missions begins with understanding autonomy and autonomicity and how to design, test, and verify systems that have those properties and, simultaneously, the capability to accomplish prescribed mission goals. Formal methods-based technologies, both projected and in development, are described in terms of their potential utility to swarm-based system developers.

  17. Stars

    NASA Astrophysics Data System (ADS)

    Capelato, Hugo Vicente

    1999-01-01

    We will begin our study with a more or less superficial inspection of the "forest" of stars that we see in the skies. The first thing we notice is that, as sources of light, they are much weaker than the Sun. Second, their apparent colors vary; from a bluish-white in most of them to a reddish-yellow, which is rarer. There is also a third aspect, though it is not very obvious to the naked eye: most of the stars group themselves in small families of two, three or more members. A good example is the Alpha Centauri, the closest star to us, which, in fact, is a triple system of stars. Another is the group of 7 stars that make up the Pleiades, which will be discussed later on. In fact, almost half of the stars are double systems with only two members, called binary stars. Most of these double stars, though together, are separated by several astronomical units (one astronomical unit, AU, is the distance from Earth to the sun: see Chapter 1), and revolve around each other over periods of several years. And yet the revolutions of some binary stars, separated by much smaller distances, occur in only a few hours! These stars are so close to each other that they can share enveloping material. Often this exchange occurs in a somewhat violent manner. Local explosions may occur, expelling matter away from the system. In other binary systems, where one of the components is a very compact, dense star, companion material flows more calmly, making up a light disk around the compact star.

  18. The LHCb Silicon Tracker

    NASA Astrophysics Data System (ADS)

    Tobin, Mark

    2013-12-01

    The LHCb experiment is designed to perform high-precision measurements of CP violation and search for new physics using the enormous flux of beauty and charm hadrons produced at the LHC. The LHCb detector is a single-arm spectrometer with excellent tracking and particle identification capabilities. The Silicon Tracker is part of the tracking system and measures very precisely the particle trajectories coming from the interaction point in the region of high occupancies around the beam axis. The LHCb Silicon Tracker covers a total sensitive area of about 12 m2 using silicon micro-strip detectors with long readout strips. It consists of one four-layer tracking station before the LHCb dipole magnet and three stations after. The detector has performed extremely well since the start of the LHC operation despite the fact that the experiment is collecting data at instantaneous luminosities well above the design value. This paper reports on the operation and performance of the Silicon Tracker during the Physics data taking at the LHC during the last two years.

  19. A quadrant-CCD star tracker

    NASA Technical Reports Server (NTRS)

    Clampin, M.; Durrance, S. T.; Barkhouser, R.; Golimowski, D. A.; Wald, A.; Fastie, W. G.; Heidtmann, D. L.; Blouke, Morley M.; Westphal, James A.; Janesick, James R.

    1990-01-01

    The characteristics of a quadrant-CCD designed for pointing and tracking are discussed with reference to its use in an adaptive optics program. The quadrant-CCD is used to correct stellar image motion proceeding from atmospheric turbulence by means of a system in which a sensor measures the image offset and sends data to a high-speed tip/tilt mirror. The design and control of the device are detailed, including four 100-micron-square pixels, the quadrant architecture, controller electronics, and data acquisition computer and interface. The transfer function is set forth in the x and y directions, and transfer curves are shown. A laboratory simulation of random image motion was conducted to evaluate the performance of the quadrant-CCD as an image motion sensor, and the experimental results are presented. The suitability of the quadrant-CCD for space-based pointing and tracking uses is demonstrated by this test and two earlier theoretical studies. Some future developments which improve performance capabilities are mentioned.

  20. CMS tracker visualization tools

    NASA Astrophysics Data System (ADS)

    Mennea, M. S.; Osborne, I.; Regano, A.; Zito, G.

    2005-08-01

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking.

  1. Tracker 300 Software

    SciTech Connect

    Wysor, R. Wes

    2006-01-12

    The Tracker300 software is downloaded to an off-the-shelf product called RCM3400/RCM3410 made by Rabbit Semiconductor. The software is a closed loop control which computes the sun's position and provides stability compensation. Using the RCM3400/RCM3410 module, the software stores and retrieves parameters from the onboard flash. The software also allows for communication with a host. It will allow the parameters to be downloaded or uploaded, it will show the status of the controller, it will provide real-time feedback, and it will send command acknowledgements. The software will capture the GPS response and ensure the internal clock is set correctly.

  2. ILC Vertex Tracker R&D

    SciTech Connect

    Battaglia, Marco; Bussat, Jean-Marie; Contarato, Devis; Denes,Peter; Glesener, Lindsay; Greiner, Leo; Hooberman, Benjamin; Shuman,Derek; Tompkins, Lauren; Vu, Chinh; Bisello, Dario; Giubilato, Piero; Pantano, Devis; Costa, Marco; La Rosa, Alessandro; Bolla, Gino; Bortoletto, Daniela; Children, Isaac

    2007-10-01

    This document summarizes past achievements, current activities and future goals of the R&D program aimed at the design, prototyping and characterization of a full detector module, equipped with monolithic pixel sensors, matching the requirements for the Vertex Tracker at the ILC. We provide a plan of activities to obtain a demonstrator multi-layered vertex tracker equipped with sensors matching the ILC requirements and realistic lightweight ladders in FY11, under the assumption that ILC detector proto-collaborations will be choosing technologies and designs for the Vertex Tracker by that time. The R&D program discussed here started at LBNL in 2004, supported by a Laboratory Directed R&D (LDRD) grant and by funding allocated from the core budget of the LBNL Physics Division and from the Department of Physics at UC Berkeley. Subsequently additional funding has been awarded under the NSF-DOE LCRD program and also personnel have become available through collaborative research with other groups. The aim of the R&D program carried out by our collaboration is to provide a well-integrated, inclusive research effort starting from physics requirements for the ILC Vertex Tracker and addressing Si sensor design and characterization, engineered ladder design, module system issues, tracking and vertex performances and beam test validation. The broad scope of this program is made possible by important synergies with existing know-how and concurrent programs both at LBNL and at the other collaborating institutions. In particular, significant overlaps with LHC detector design, SLHC R&D as well as prototyping for the STAR upgrade have been exploited to optimize the cost per deliverable of our program. This activity is carried out as a collaborative effort together with Accelerator and Fusion Research, the Engineering and the Nuclear Science Divisions at LBNL, INFN and the Department of Physics in Padova, Italy, INFN and the Department of Physics in Torino, Italy and the Department

  3. Tracker 300 Software

    Energy Science and Technology Software Center (ESTSC)

    2006-01-12

    The Tracker300 software is downloaded to an off-the-shelf product called RCM3400/RCM3410 made by Rabbit Semiconductor. The software is a closed loop control which computes the sun's position and provides stability compensation. Using the RCM3400/RCM3410 module, the software stores and retrieves parameters from the onboard flash. The software also allows for communication with a host. It will allow the parameters to be downloaded or uploaded, it will show the status of the controller, it will providemore » real-time feedback, and it will send command acknowledgements. The software will capture the GPS response and ensure the internal clock is set correctly.« less

  4. Silicon tracker data acquisition

    SciTech Connect

    Haynes, W.J.

    1997-12-31

    Large particle physics experiments are making increasing technological demands on the design and implementation of real-time data acquisition systems. The LHC will have bunch crossing intervals of 25 nanoseconds and detectors, such as CMS, will contain over 10 million electronic channels. Readout systems will need to cope with 100 kHz rates of 1 MByte-sized events. Over 70% of this voluminous flow will stem from silicon tracker and MSGC devices. This paper describes the techniques currently being harnessed from ASIC devices through to modular microprocessor-based architectures around standards such as VMEbus and PCI. In particular, the experiences gained at the HERA H1 experiment are highlighted where many of the key technological concepts have already been im implemented.

  5. Mechatronic Prototype of Parabolic Solar Tracker.

    PubMed

    Morón, Carlos; Díaz, Jorge Pablo; Ferrández, Daniel; Ramos, Mari Paz

    2016-01-01

    In the last 30 years numerous attempts have been made to improve the efficiency of the parabolic collectors in the electric power production, although most of the studies have focused on the industrial production of thermoelectric power. This research focuses on the application of this concentrating solar thermal power in the unexplored field of building construction. To that end, a mechatronic prototype of a hybrid paraboloidal and cylindrical-parabolic tracker based on the Arduido technology has been designed. The prototype is able to measure meteorological data autonomously in order to quantify the energy potential of any location. In this way, it is possible to reliably model real commercial equipment behavior before its deployment in buildings and single family houses. PMID:27314359

  6. Mechatronic Prototype of Parabolic Solar Tracker

    PubMed Central

    Morón, Carlos; Díaz, Jorge Pablo; Ferrández, Daniel; Ramos, Mari Paz

    2016-01-01

    In the last 30 years numerous attempts have been made to improve the efficiency of the parabolic collectors in the electric power production, although most of the studies have focused on the industrial production of thermoelectric power. This research focuses on the application of this concentrating solar thermal power in the unexplored field of building construction. To that end, a mechatronic prototype of a hybrid paraboloidal and cylindrical-parabolic tracker based on the Arduido technology has been designed. The prototype is able to measure meteorological data autonomously in order to quantify the energy potential of any location. In this way, it is possible to reliably model real commercial equipment behavior before its deployment in buildings and single family houses. PMID:27314359

  7. WGM Temperature Tracker

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V.

    2012-01-01

    This software implements digital control of a WGM (whispering-gallerymode) resonator temperature based on the dual-mode approach. It comprises one acquisition (dual-channel) and three control modules. The interaction of the proportional-integral loops is designed in the original way, preventing the loops from fighting. The data processing is organized in parallel with the acquisition, which allows the computational overhead time to be suppressed or often completely avoided. WGM resonators potentially provide excellent optical references for metrology, clocks, spectroscopy, and other applications. However, extremely accurate (below micro-Kelvin) temperature stabilization is required. This software allows one specifically advantageous method of such stabilization to be implemented, which is immune to a variety of effects that mask the temperature variation. WGM Temperature Tracker 2.3 (see figure) is a LabVIEW code developed for dual-mode temperature stabilization of WGM resonators. It has allowed for the temperature stabilization at the level of 200 nK with one-second integration time, and 6 nK with 10,000-second integration time, with the above room-temperature set point. This software, in conjunction with the appropriate hardware, can be used as a noncryogenic temperature sensor/ controller with sub-micro-Kelvin sensitivity, which at the time of this reporting considerably outperforms the state of the art.

  8. Controls Request Tracker

    SciTech Connect

    White, Karen S; Kasemir, Kay; Hartman, Steven M; Verstovsek, Igor

    2009-01-01

    Controls groups at large accelerators are routinely called upon to build and support controls for virtually all machine systems. While construction projects within the US DOE system are normally carefully planned and tracked by project management professionals, this support ends when construction milestones are met. However, once construction is complete, work continues as the group performs ongoing support and maintenance while also implementing requested system improvements and upgrades. With customers from virtually every accelerator and experiment group, the demands on the group often exceed the capacity of available resources. This type of diverse workload needs to be well organized and managed in order set proper priorities and ensure efficient use of resources. At SNS, we have collaborated with Cosylab to develop Controls Request Tracker (CRT), which is adapted from the Cosylab Project Manager (CPM) software. The resulting system not only provides standard request tracking features, but is interfaced to the SNS Logbook and work control system. This paper will discuss CRT and how we use it to manage the work of our controls group.

  9. Solid state, autonomous attitude estimation system

    NASA Astrophysics Data System (ADS)

    Rose, C. E.; Runyan, D. P.

    This paper describes the means by which star tracker measurements can be used to estimate the rotational position of a space vehicle upon which the trackers are mounted. A nonlinear least squares approach is taken in which a novel method of normalizing the attitude quaternion is developed. Examples of convergence histories are included, as well as an estimate of the memory needed to hold the algorithm.

  10. Schedule-Tracker Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Tracker provides effective method for tracking tasks "past due" and/or "near term". Generates reports for each responsible staff member having one or more assigned tasks falling within two listed categories. Schedule Organizer (SO) (COSMIC program MSC-21525), Schedule Tracker (ST), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  11. Hyperspectral Imager-Tracker

    NASA Technical Reports Server (NTRS)

    Agurok, Llya

    2013-01-01

    The Hyperspectral Imager-Tracker (HIT) is a technique for visualization and tracking of low-contrast, fast-moving objects. The HIT architecture is based on an innovative and only recently developed concept in imaging optics. This innovative architecture will give the Light Prescriptions Innovators (LPI) HIT the possibility of simultaneously collecting the spectral band images (hyperspectral cube), IR images, and to operate with high-light-gathering power and high magnification for multiple fast- moving objects. Adaptive Spectral Filtering algorithms will efficiently increase the contrast of low-contrast scenes. The most hazardous parts of a space mission are the first stage of a launch and the last 10 kilometers of the landing trajectory. In general, a close watch on spacecraft operation is required at distances up to 70 km. Tracking at such distances is usually associated with the use of radar, but its milliradian angular resolution translates to 100- m spatial resolution at 70-km distance. With sufficient power, radar can track a spacecraft as a whole object, but will not provide detail in the case of an accident, particularly for small debris in the onemeter range, which can only be achieved optically. It will be important to track the debris, which could disintegrate further into more debris, all the way to the ground. Such fragmentation could cause ballistic predictions, based on observations using high-resolution but narrow-field optics for only the first few seconds of the event, to be inaccurate. No optical imager architecture exists to satisfy NASA requirements. The HIT was developed for space vehicle tracking, in-flight inspection, and in the case of an accident, a detailed recording of the event. The system is a combination of five subsystems: (1) a roving fovea telescope with a wide 30 field of regard; (2) narrow, high-resolution fovea field optics; (3) a Coude optics system for telescope output beam stabilization; (4) a hyperspectral

  12. Autonomic neuropathies

    NASA Technical Reports Server (NTRS)

    Low, P. A.

    1998-01-01

    A limited autonomic neuropathy may underlie some unusual clinical syndromes, including the postural tachycardia syndrome, pseudo-obstruction syndrome, heat intolerance, and perhaps chronic fatigue syndrome. Antibodies to autonomic structures are common in diabetes, but their specificity is unknown. The presence of autonomic failure worsens prognosis in the diabetic state. Some autonomic neuropathies are treatable. Familial amyloid polyneuropathy may respond to liver transplantation. There are anecdotal reports of acute panautonomic neuropathy responding to intravenous gamma globulin. Orthostatic hypotension may respond to erythropoietin or midodrine.

  13. Autonomous software: Myth or magic?

    NASA Astrophysics Data System (ADS)

    Allan, A.; Naylor, T.; Saunders, E. S.

    2008-03-01

    We discuss work by the eSTAR project which demonstrates a fully closed loop autonomous system for the follow up of possible micro-lensing anomalies. Not only are the initial micro-lensing detections followed up in real time, but ongoing events are prioritised and continually monitored, with the returned data being analysed automatically. If the ``smart software'' running the observing campaign detects a planet-like anomaly, further follow-up will be scheduled autonomously and other telescopes and telescope networks alerted to the possible planetary detection. We further discuss the implications of this, and how such projects can be used to build more general autonomous observing and control systems.

  14. The Do/ scintillating fiber tracker

    SciTech Connect

    Bross, A.; Gutierrez, G.; Grunendahl, S.; Lincoln, D.; Ramberg, E.; Ray, R.; Ruchti, R.; Warchol, J.; Wayne, M.; Choic, S.

    1998-11-01

    The Do/ detector is being upgraded in preparation for the next collider run at Fermilab. The Central Fiber Tracker discussed in this report is a major component of the Do/ upgrade. The expected Tevatron luminosity of 2{times}10{sup 32} cm{sup {minus}2} sec{sup {minus}1}, the 132ns bunch crossing time, and the Do/ detector constraints of a 2 Tesla solenoid and a 52 cm lever arm, make a scintillating fiber based tracker an optimal choice for the upgrade of the Do/ detector. {copyright} {ital 1998 American Institute of Physics.}

  15. CSTAR star catalogue development

    NASA Technical Reports Server (NTRS)

    Uhde-Lacovara, J. A.

    1986-01-01

    The Continuous Stellar Tracking Attitude Reference (CSTAR) system is an in-house project for the Space Station to provide high accuracy, drift free attitude and angular rate information for the GN&C system. Constraints exist on the star catalogue incorporated in the system. These constraints include the following: mass memory allocated for catalogue storage, star tracker imaging sensitivity, the minimum resolvable separation angle between stars, the width of the field of view of the star tracker, and the desired number of stars to be tracked in a field of view. The Smithsonian Astrophysical Observatory (SAO) catalogue is the basis reference for this study. As it stands, the SAO does not meet the requirements of any of the above constraints. Star selection algorithms have been devised for catalogue optimization. Star distribution statistics have been obtained to aid in the development of these rules. VAX based software has been developed to implement the star selection algorithms. The software is modular and provides a design tool to tailor the catalogue to available star tracker technology. The SAO catalogue has been optimized for the requirements of the present CSTAR system.

  16. The Secure, Transportable, Autonomous Reactor System

    SciTech Connect

    Brown, N.W.; Hassberger, J.A.; Smith, C.; Carelli, M.; Greenspan, E.; Peddicord, K.L.; Stroh, K.; Wade, D.C.; Hill, R.N.

    1999-05-27

    The Secure, Transportable, Autonomous Reactor (STAR) system is a development architecture for implementing a small nuclear power system, specifically aimed at meeting the growing energy needs of much of the developing world. It simultaneously provides very high standards for safety, proliferation resistance, ease and economy of installation, operation, and ultimate disposition. The STAR system accomplishes these objectives through a combination of modular design, factory manufacture, long lifetime without refueling, autonomous control, and high reliability.

  17. Advanced stellar compass onboard autonomous orbit determination, preliminary performance.

    PubMed

    Betto, Maurizio; Jørgensen, John L; Jørgensen, Peter S; Denver, Troelz

    2004-05-01

    Deep space exploration is in the agenda of the major space agencies worldwide; certainly the European Space Agency (SMART Program) and the American NASA (New Millennium Program) have set up programs to allow the development and the demonstration of technologies that can reduce the risks and the cost of deep space missions. From past experience, it appears that navigation is the Achilles heel of deep space missions. Performed on ground, this imposes considerable constraints on the entire system and limits operations. This makes it is very expensive to execute, especially when the mission lasts several years and, furthermore, it is not failure tolerant. Nevertheless, to date, ground navigation has been the only viable solution. The technology breakthrough of advanced star trackers, like the advanced stellar compass (ASC), might change this situation. Indeed, exploiting the capabilities of this instrument, the authors have devised a method to determine the orbit of a spacecraft autonomously, onboard, and without a priori knowledge of any kind. The solution is robust and fast. This paper presents the preliminary performance obtained during the ground testing in August 2002 at the Mauna Kea Observatories. The main goals were: (1) to assess the robustness of the method in solving autonomously, onboard, the position lost-in-space problem; (2) to assess the preliminary accuracy achievable with a single planet and a single observation; (3) to verify the autonomous navigation (AutoNav) module could be implemented into an ASC without degrading the attitude measurements; and (4) to identify the areas of development and consolidation. The results obtained are very encouraging. PMID:15220158

  18. TacNet Tracker Software

    Energy Science and Technology Software Center (ESTSC)

    2008-08-04

    The TacNet Tracker will be used for the monitoring and real-time tracking of personnel and assets in an unlimited number of specific applications. The TacNet Tracker software is a VxWorks Operating System based programming package that controls the functionality for the wearable Tracker. One main use of the TacNet Tracker is in Blue Force Tracking, the ability to track the good guys in an adversarial situation or in a force-on-force or real battle conditions. Themore » purpose of blue force tracking is to provide situational awareness to the battlefield commanders and personnel. There are practical military applications with the TacNet Tracker.The mesh network is a wireless IP communications network that moves data packets from source IP addresses to specific destination IP addresses. Addresses on the TacNet infrastructure utilize an 8-bit network mask (255.0.0.0). In other words, valid TacNet addresses range from 10.0.0.1 to 10.254.254.254. The TacNet software design uses uni-cast transmission techniques because earlier mesh network software releases did not provide for the ability to utilize multi-cast data movement. The TacNet design employs a list of addresses to move information within the TacNet infrastructure. For example, a convoy text file containing the IP addresses of all valid receivers of TacNet information could be used for transmitting the information and for limiting transmission to addresses on the list.« less

  19. TacNet Tracker Software

    SciTech Connect

    WISEMAN, JAMES; & STEVENS, JAMES

    2008-08-04

    The TacNet Tracker will be used for the monitoring and real-time tracking of personnel and assets in an unlimited number of specific applications. The TacNet Tracker software is a VxWorks Operating System based programming package that controls the functionality for the wearable Tracker. One main use of the TacNet Tracker is in Blue Force Tracking, the ability to track the good guys in an adversarial situation or in a force-on-force or real battle conditions. The purpose of blue force tracking is to provide situational awareness to the battlefield commanders and personnel. There are practical military applications with the TacNet Tracker.The mesh network is a wireless IP communications network that moves data packets from source IP addresses to specific destination IP addresses. Addresses on the TacNet infrastructure utilize an 8-bit network mask (255.0.0.0). In other words, valid TacNet addresses range from 10.0.0.1 to 10.254.254.254. The TacNet software design uses uni-cast transmission techniques because earlier mesh network software releases did not provide for the ability to utilize multi-cast data movement. The TacNet design employs a list of addresses to move information within the TacNet infrastructure. For example, a convoy text file containing the IP addresses of all valid receivers of TacNet information could be used for transmitting the information and for limiting transmission to addresses on the list.

  20. A technique for computation of star magnitudes relative to an optical sensor

    NASA Technical Reports Server (NTRS)

    Rhoads, J. W.

    1972-01-01

    The theory and techniques used to compute star magnitudes relative to any optical detector (such as the Mariner Mars 1971 Canopus star tracker) are described. Results are given relative to various star detectors.

  1. Autonomic hyperreflexia

    MedlinePlus

    The most common cause of autonomic hyperreflexia is spinal cord injury. The nervous system of people with this condition ... Flushed (red) skin above the level of the spinal cord injury High blood pressure Slow pulse or fast pulse ...

  2. Autonomic hyperreflexia

    MedlinePlus

    ... The most common cause of autonomic hyperreflexia is spinal cord injury. The nervous system of people with this condition ... Flushed (red) skin above the level of the spinal cord injury High blood pressure Slow pulse or fast pulse ...

  3. Development of a direct match technique for star identification on the SWAS mission

    NASA Technical Reports Server (NTRS)

    Daniel, Walter K.; Correll, Thomas E.; Anderson, Mark O.

    1995-01-01

    A direct match technique for star identification was developed for use with the star tracker on the SWAS (Submillimeter Wave Astronomy Satellite) spacecraft. In this technique, tracker searches are used in a two-step process for an implicit direct match star identification. A simulation of the star acquisition process was created and used in the preparation of guide star selection requirements. Flight software implementing this star acquisition technique has been developed and tested.

  4. LHCb Upgrade: Scintillating Fibre Tracker

    NASA Astrophysics Data System (ADS)

    Tobin, Mark

    2016-07-01

    The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres and a custom ASIC will be used to digitise the signals from the SiPMs. The evolution of the design since the Technical Design Report in 2014 and the latest R & D results are presented.

  5. The LHCb Silicon Tracker Project

    NASA Astrophysics Data System (ADS)

    Agari, M.; Bauer, C.; Baumeister, D.; Blouw, J.; Hofmann, W.; Knöpfle, K. T.; Löchner, S.; Schmelling, M.; Pugatch, V.; Bay, A.; Carron, B.; Frei, R.; Jiminez-Otero, S.; Tran, M.-T.; Voss, H.; Adeva, B.; Esperante, D.; Lois, C.; Vasquez, P.; Bernhard, R. P.; Bernet, R.; Ermoline, Y.; Gassner, J.; Köstner, S.; Lehner, F.; Needham, M.; Siegler, M.; Steinkamp, O.; Straumann, U.; Vollhardt, A.; Volyanskyy, D.

    2006-01-01

    Two silicon strip detectors, the Trigger Tracker(TT) and the Inner Tracker(IT) will be constructed for the LHCb experiment. Transverse momentum information extracted from the TT will be used in the Level 1 trigger. The IT is part of the main tracking system behind the magnet. Both silicon detectors will be read out using a custom-developed chip by the ASIC lab in Heidelberg. The signal-over-noise behavior and performance of various geometrical designs of the silicon sensors, in conjunction with the Beetle read-out chip, have been extensively studied in test beam experiments. Results from those experiments are presented, and have been used in the final choice of sensor geometry.

  6. Introduction to Mini Muon Tracker

    SciTech Connect

    Borozdin, Konstantin N.

    2012-08-13

    Using a mini muon tracker developed at the Los Alamos National Laboratory we performed experiments of simple landscapes of various materials, including TNT, 9501, lead, tungsten, aluminium, and water. Most common scenes are four two inches thick step wedges of different dimensions: 12-inch x 12-inch, 12-inch x 9-inch, 12-inch x 6-inch, and 12-inch x 3-inch; and a one three inches thick hemisphere of lead with spherical hollow, and a similar full lead sphere.

  7. The CMS tracker control system

    NASA Astrophysics Data System (ADS)

    Dierlamm, A.; Dirkes, G. H.; Fahrer, M.; Frey, M.; Hartmann, F.; Masetti, L.; Militaru, O.; Shah, S. Y.; Stringer, R.; Tsirou, A.

    2008-07-01

    The Tracker Control System (TCS) is a distributed control software to operate about 2000 power supplies for the silicon modules of the CMS Tracker and monitor its environmental sensors. TCS must thus be able to handle about 104 power supply parameters, about 103 environmental probes from the Programmable Logic Controllers of the Tracker Safety System (TSS), about 105 parameters read via DAQ from the DCUs in all front end hybrids and from CCUs in all control groups. TCS is built on top of an industrial SCADA program (PVSS) extended with a framework developed at CERN (JCOP) and used by all LHC experiments. The logical partitioning of the detector is reflected in the hierarchical structure of the TCS, where commands move down to the individual hardware devices, while states are reported up to the root which is interfaced to the broader CMS control system. The system computes and continuously monitors the mean and maximum values of critical parameters and updates the percentage of currently operating hardware. Automatic procedures switch off selected parts of the detector using detailed granularity and avoiding widespread TSS intervention.

  8. Upgrade of the CMS tracker

    NASA Astrophysics Data System (ADS)

    Tricomi, A.

    2014-03-01

    The LHC machine is planning an upgrade program which will smoothly bring the luminosity up to or above 5 × 1034 cm-2s-1 sometimes after 2020, to possibly reach an integrated luminosity of 3000 fb-1 at the end of that decade. The foreseen increases of both the instantaneous and the integrated luminosity by the LHC during the next ten years will necessitate a stepwise upgrade of the CMS tracking detector. During the extended end-of-year shutdown 2016-2017 the pixel detector will be exchanged with a new one. The so-called Phase1 Pixel foresees one additional barrel layer and one additional end-cap disk, a new readout chip, reduction of material, and the installation of more efficient cooling and powering systems. In the so-called Phase2, when LHC will reach the High Luminosity (HL-LHC) phase, CMS will need a completely new Tracker detector, in order to fully exploit the high-demanding operating conditions and the delivered luminosity. The new Tracker should have also trigger capabilities. To achieve such goals, R&D activities are ongoing to explore options and develop solutions that would allow including tracking information at Level-1. The design choices for the CMS pixel and outer tracker upgrades are discussed along with some highlights of the R&D activities.

  9. Activity trackers: a critical review.

    PubMed

    Lee, Jeon; Finkelstein, Joseph

    2014-01-01

    The wearable consumer health devices can be mainly divided into activity trackers, sleep trackers, and stress management devices. These devices are widely advertised to provide positive effects on the user's daily behaviours and overall heath. However, objective evidence supporting these claims appears to be missing. The goal of this study was to review available evidence pertaining to performance of activity trackers. A comprehensive review of available information has been conducted for seven representative devices and the validity of marketing claims was assessed. The device assessment was based on availability of verified output metrics, theoretical frameworks, systematic evaluation, and FDA clearance. The review identified critical absence of supporting evidence of advertised functions and benefits for the majority of the devices. Six out of seven devices did not provide any information on sensor accuracy and output validity at all. Possible underestimation or overestimation of specific health indicators reported to consumers was not clearly disclosed to the public. Furthermore, significant limitations of these devices which can be categorized into user restrictions, user responsibilities and company disclaimers could not be easily found or comprehended by unsophisticated users and may represent a serious health hazard. PMID:25160247

  10. Astronavigation System as an Autonomous Enhancement Suite for a Strapdown Inertial Navigation System: An Evaluation

    NASA Astrophysics Data System (ADS)

    Ali, Jamshaid

    2009-01-01

    The determination of spacecraft coordinates is embodied by a navigation solution with high degree of autonomy, high precision and reliability. The foremost requirement for the solution of this problem is a strapdown inertial navigation system (SINS), which is autonomous, reliable and jamming resistant, but at the same time, errors in SINS increase with time. Therefore, for the SINS eiror correction, astronavigation system (ANS) is used as an additional navaid. This paper considers the ANS as an enhancement source for the SINS and presents its theoretical and practical aspects. The typical ANS makes use of star-trackers which are expensive, complicated in their structure and demand a-priori definition and vigilant preparation of each onboard attitude fix. To make this system cost effective and simple, an advanced configuration employs a charge coupled device (CCD) based star sensor rigidly mounted on a strapdown inertial measurement unit (SIMU). Consequently, in this evaluation, the ANS makes use of CCD based star sensors. Simulation results are presented to demonstrate the validity of the method for improving the navigation reliability and performance.

  11. Autonomous Soaring

    NASA Technical Reports Server (NTRS)

    Lin, Victor P.

    2007-01-01

    This viewgraph presentation reviews the autonomous soaring flight of unmanned aerial vehicles (UAV). It reviews energy sources for UAVs, and two examples of UAV's that used alternative energy sources, and thermal currents for soaring. Examples of flight tests, plans, and results are given. Ultimately, the concept of a UAV harvesting energy from the atmosphere has been shown to be feasible with existing technology.

  12. The h1 Silicon Tracker

    NASA Astrophysics Data System (ADS)

    List, Benno

    2004-07-01

    The silicon tracker of the H1 experiment at HERA consists of a barrel part and two endcaps with disks. The barrel part has 2 layers of double sided strip sensors with 81920 readout channels. The forward part uses 7 wheels of single sided strip detectors that measure three coordinates (r, u, and v) with 92160 channels. The backward part uses single sided strip detectors in 6 wheels, measuring the u and v coordinates with 84480 channels. These wheels are intersprsed with 4 wheels of pad detectors that provide fast triggering signals.

  13. The CDF silicon vertex tracker

    SciTech Connect

    A. Cerri et al.

    2000-10-10

    Real time pattern recognition is becoming a key issue in many position sensitive detector applications. The CDF collaboration is building SVT: a specialized electronic device designed to perform real time track reconstruction using the silicon vertex detector (SVX II). This will strongly improve the CDF capability of triggering on events containing b quarks, usually characterized by the presence of a secondary vertex. SVT is designed to reconstruct in real time charged particles trajectories using data coming from the Silicon Vertex detector and the Central Outer Tracker drift chamber. The SVT architecture and algorithm have been specially tuned to minimize processing time without degrading parameter resolution.

  14. Teaching optical phenomena with Tracker

    NASA Astrophysics Data System (ADS)

    Rodrigues, M.; Simeão Carvalho, P.

    2014-11-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

  15. Autonomous Navigation Using Celestial Objects

    NASA Technical Reports Server (NTRS)

    Folta, David; Gramling, Cheryl; Leung, Dominic; Belur, Sheela; Long, Anne

    1999-01-01

    In the twenty-first century, National Aeronautics and Space Administration (NASA) Enterprises envision frequent low-cost missions to explore the solar system, observe the universe, and study our planet. Satellite autonomy is a key technology required to reduce satellite operating costs. The Guidance, Navigation, and Control Center (GNCC) at the Goddard Space Flight Center (GSFC) currently sponsors several initiatives associated with the development of advanced spacecraft systems to provide autonomous navigation and control. Autonomous navigation has the potential both to increase spacecraft navigation system performance and to reduce total mission cost. By eliminating the need for routine ground-based orbit determination and special tracking services, autonomous navigation can streamline spacecraft ground systems. Autonomous navigation products can be included in the science telemetry and forwarded directly to the scientific investigators. In addition, autonomous navigation products are available onboard to enable other autonomous capabilities, such as attitude control, maneuver planning and orbit control, and communications signal acquisition. Autonomous navigation is required to support advanced mission concepts such as satellite formation flying. GNCC has successfully developed high-accuracy autonomous navigation systems for near-Earth spacecraft using NASA's space and ground communications systems and the Global Positioning System (GPS). Recently, GNCC has expanded its autonomous navigation initiative to include satellite orbits that are beyond the regime in which use of GPS is possible. Currently, GNCC is assessing the feasibility of using standard spacecraft attitude sensors and communication components to provide autonomous navigation for missions including: libration point, gravity assist, high-Earth, and interplanetary orbits. The concept being evaluated uses a combination of star, Sun, and Earth sensor measurements along with forward-link Doppler

  16. Autonomic dysreflexia

    PubMed Central

    Milligan, James; Lee, Joseph; McMillan, Colleen; Klassen, Hilary

    2012-01-01

    Abstract Objective To raise family physicians’ awareness of autonomic dysreflexia (AD) in patients with spinal cord injury (SCI) and to provide some suggestions for intervention. Sources of information MEDLINE was searched from 1970 to July 2011 using the terms autonomic dysreflexia and spinal cord injury with family medicine or primary care. Other relevant guidelines and resources were reviewed and used. Main message Family physicians often lack confidence in treating patients with SCI, see them as complex and time-consuming, and feel undertrained to meet their needs. Family physicians provide a vital component of the health care of such patients, and understanding of the unique medical conditions related to SCI is important. Autonomic dysreflexia is an important, common, and potentially serious condition with which many family physicians are unfamiliar. This article will review the signs and symptoms of AD and offer some acute management options and preventive strategies for family physicians. Conclusion Family physicians should be aware of which patients with SCI are susceptible to AD and monitor those affected by it. Outlined is an approach to acute management. Family physicians play a pivotal role in prevention of AD through education (of the patient and other health care providers) and incorporation of strategies such as appropriate bladder, bowel, and skin care practices and warnings and management plans in the medical chart. PMID:22893332

  17. Autonomous vehicles

    SciTech Connect

    Meyrowitz, A.L.; Blidberg, D.R.; Michelson, R.C. |

    1996-08-01

    There are various kinds of autonomous vehicles (AV`s) which can operate with varying levels of autonomy. This paper is concerned with underwater, ground, and aerial vehicles operating in a fully autonomous (nonteleoperated) mode. Further, this paper deals with AV`s as a special kind of device, rather than full-scale manned vehicles operating unmanned. The distinction is one in which the AV is likely to be designed for autonomous operation rather than being adapted for it as would be the case for manned vehicles. The authors provide a survey of the technological progress that has been made in AV`s, the current research issues and approaches that are continuing that progress, and the applications which motivate this work. It should be noted that issues of control are pervasive regardless of the kind of AV being considered, but that there are special considerations in the design and operation of AV`s depending on whether the focus is on vehicles underwater, on the ground, or in the air. The authors have separated the discussion into sections treating each of these categories.

  18. A Rollercoaster Viewed through Motion Tracker Data

    ERIC Educational Resources Information Center

    Pendrill, Ann-Marie; Rodjegard, Henrik

    2005-01-01

    A motion tracker measures acceleration and rotation in three dimensions, sufficient for a complete determination of the motion. In this article, a rollercoaster ride is analysed with reference to motion tracker data. The use of this type of data in education is discussed as a way to deepen students' understanding of concepts related to force and…

  19. The Chesapeake Laser Tracker in Industrial Metrology

    SciTech Connect

    Ruland, Robert E.; /SLAC

    2005-08-16

    In the summer of 1992, the survey and alignment team at the Stanford Linear Accelerator Center acquired a CMS3000 laser tracker manufactured by Chesapeake Laser Systems in Lanham, Maryland. This paper gives a description of the principles of operation and calibration of the tracker. Several applications are explained and the results shared.

  20. Ruby on Rails Issue Tracker

    NASA Technical Reports Server (NTRS)

    Rodriguez, Juan Jared

    2014-01-01

    The purpose of this report is to detail the tasks accomplished as a NASA NIFS intern for the summer 2014 session. This internship opportunity is to develop an issue tracker Ruby on Rails web application to improve the communication of developmental anomalies between the Support Software Computer Software Configuration Item (CSCI) teams, System Build and Information Architecture. As many may know software development is an arduous, time consuming, collaborative effort. It involves nearly as much work designing, planning, collaborating, discussing, and resolving issues as effort expended in actual development. This internship opportunity was put in place to help alleviate the amount of time spent discussing issues such as bugs, missing tests, new requirements, and usability concerns that arise during development and throughout the life cycle of software applications once in production.

  1. Silicon photomultipliers for scintillating trackers

    NASA Astrophysics Data System (ADS)

    Rabaioli, S.; Berra, A.; Bolognini, D.; Bonvicini, V.; Bosisio, L.; Ciano, S.; Iugovaz, D.; Lietti, D.; Penzo, A.; Prest, M.; Rashevskaya, I.; Reia, S.; Stoppani, L.; Vallazza, E.

    2012-12-01

    In recent years, silicon photomultipliers (SiPMs) have been proposed as a new kind of readout device for scintillating detectors in many experiments. A SiPM consists of a matrix of parallel-connected pixels, which are independent photon counters working in Geiger mode with very high gain (∼106). This contribution presents the use of an array of eight SiPMs (manufactured by FBK-irst) for the readout of a scintillating bar tracker (a small size prototype of the Electron Muon Ranger detector for the MICE experiment). The performances of the SiPMs in terms of signal to noise ratio, efficiency and time resolution will be compared to the ones of a multi-anode photomultiplier tube (MAPMT) connected to the same bars. Both the SiPMs and the MAPMT are interfaced to a VME system through a 64 channel MAROC ASIC.

  2. ST - SCHEDULE TRACKER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST, and Schedule Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum numbers can be modified by the user. ST requires the VMS Operating System on DEC VAX and was written in PL/1 and DEC Command Language (DCL). The program requires a memory of 233KB. ST can be purchased separately or in a package (COSMIC Program COS-10021) containing SO, ST, and SRG. ST was developed in 1985.

  3. Autonomous control

    NASA Technical Reports Server (NTRS)

    Brown, Barbara

    1990-01-01

    KSC has been developing the Knowledge-Based Autonomous Test Engineer (KATE), which is a tool for performing automated monitoring, diagnosis, and control of electromechanical devices. KATE employs artificial intelligence computing techniques to perform these functions. The KATE system consists of a generic shell and a knowledge base. The KATE shell is the portion of the system which performs the monitoring, diagnosis, and control functions. It is generic in the sense that it is application independent. This means that the monitoring activity, for instance, will be performed with the same algorithms regardless of the particular physical device being used. The knowledge base is the portion of the system which contains specific functional and behavorial information about the physical device KATE is working with. Work is nearing completion on a project at KSC to interface a Texas Instruments Explorer running a LISP version of KATE with a Generic Checkout System (GCS) test-bed to control a physical simulation of a shuttle tanking system (humorously called the Red Wagon because of its color and mobility). The Autonomous Control System (ACS) project supplements and extends the KATE/GCS project by adding three other major activities. The activities include: porting KATE from the Texas Instruments Explorer machine to an Intel 80386-based UNIX workstation in the LISP language; rewriting KATE as necessary to run on the same 80386 workstation but in the Ada language; and investigating software and techniques to translate ANSI Standard Common LISP to Mil Standard Ada. Primary goals of this task are as follows: (1) establish the advantages of using expert systems to provide intelligent autonomous software for Space Station Freedom applications; (2) determine the feasibility of using Ada as the run-time environment for model-based expert systems; (3) provide insight into the advantages and disadvantagesof using LISP or Ada in the run-time environment for expert systems; and (4

  4. INL Autonomous Navigation System

    Energy Science and Technology Software Center (ESTSC)

    2005-03-30

    The INL Autonomous Navigation System provides instructions for autonomously navigating a robot. The system permits high-speed autonomous navigation including obstacle avoidance, waypoing navigation and path planning in both indoor and outdoor environments.

  5. The D0 silicon microstrip tracker

    NASA Astrophysics Data System (ADS)

    Quinn, Breese; D0 Collaboration

    2003-03-01

    The D0 collaboration has completed building a 793,000 channel silicon microstrip tracker for the D0 upgrade. The tracker consists of 768 ladder and wedge assemblies including both single- and double-sided detectors. Detector readout utilizes the SVX-IIE radiation hard chip with on-chip digitization and sparsification. A brief review of the detector design is presented along with results from the assembly and testing processes. The operation of the full readout chain and the performance of the silicon tracker are described. Finally, lessons for future production of large scale tracking systems are discussed.

  6. Personal Activity Trackers and the Quantified Self.

    PubMed

    Hoy, Matthew B

    2016-01-01

    Personal activity trackers are an inexpensive and easy way for people to record their physical activity and simple biometric data. As these devices have increased in availability and sophistication, their use in daily life and in medicine has grown. This column will briefly explore what these devices are, what types of data they can track, and how that data can be used. It will also discuss potential problems with trackers and how librarians can help patients and physicians manage and protect activity data. A brief list of currently available activity trackers is also included. PMID:26794199

  7. The LHCb silicon tracker: running experience

    NASA Astrophysics Data System (ADS)

    Saornil Gamarra, S.

    2013-02-01

    The LHCb Silicon Tracker is part of the main tracking system of the LHCb detector at the LHC. It measures very precisely the particle trajectories coming from the interaction point in the region of high occupancies around the beam axis. It covers the full acceptance angle in front of the dipole magnet in the Tracker Turicensis station and the innermost part around the beam axis in the three Inner Tracker stations downstream of the magnet. The Silicon Tracker covers a sensitive area of 12 m2 using silicon micro-strip sensors with very long readout strips. We report on running experience for the experiment. Focussing on electronic and hardware issues we describe some of the lessons learned and pitfalls encountered after three years of successful operation.

  8. Instruction manual for Sandia's laser tracker

    SciTech Connect

    Bauhs, K.C.

    1982-06-01

    This report is a supplement to SAND80-2049/1. It contains additional drawings and information for hardware described in Volume 1, more troubleshooting procedures for several systems in the Laser Tracker Facility, and corrections for volume 1.

  9. My Game Plan: Food and Activity Tracker

    MedlinePlus

    ... THIS WEEK… FOR CUTTING FAT GRAMS: FOR CUTTING CALORIES: FOR GETTING MORE PHYSICAL ACTIVITY: FROM — TO HHS' ... AND DRINK TRACKER AMOUNT /NAME /DESCRIPTION FAT GRAMS CALORIES 1/2 cup oatmeal 1 73 1 cup ...

  10. Commissioning of the Cms Tracker Outer Barrel

    NASA Astrophysics Data System (ADS)

    Bloch, Christoph

    2006-04-01

    Fully equipped final substructures of the CMS Tracker are installed in a dedicated mechanical support, the Cosmic Rack, providing a geometry suitable for tracking cosmic muons, and equipped with a dedicated trigger that allows the selection of tracks synchronous with the fast readout electronics. Data collected at room temperature and at the tracker operating temperature of -10°C can be used to test reconstruction and alignment algorithms for the tracker, as well as to perform a detailed qualification of the geometry and the functionality of the structures at different temperatures. The CMS Monte Carlo simulation has been adapted to the geometry of the cosmic rack, and the comparison with the data will provide a valuable test to improve the tracker simulation in CMS.

  11. Silicon Tracker Design for the ILC

    SciTech Connect

    Nelson, T.; /SLAC

    2005-07-27

    The task of tracking charged particles in energy frontier collider experiments has been largely taken over by solid-state detectors. While silicon microstrip trackers offer many advantages in this environment, large silicon trackers are generally much more massive than their gaseous counterparts. Because of the properties of the machine itself, much of the material that comprises a typical silicon microstrip tracker can be eliminated from a design for the ILC. This realization is the inspiration for a tracker design using lightweight, short, mass-producible modules to tile closed, nested cylinders with silicon microstrips. This design relies upon a few key technologies to provide excellent performance with low cost and complexity. The details of this concept are discussed, along with the performance and status of the design effort.

  12. Power Studies for the CMS Pixel Tracker

    SciTech Connect

    Todri, A.; Turqueti, M.; Rivera, R.; Kwan, S.; /Fermilab

    2009-01-01

    The Electronic Systems Engineering Department of the Computing Division at the Fermi National Accelerator Laboratory is carrying out R&D investigations for the upgrade of the power distribution system of the Compact Muon Solenoid (CMS) Pixel Tracker at the Large Hadron Collider (LHC). Among the goals of this effort is that of analyzing the feasibility of alternative powering schemes for the forward tracker, including DC to DC voltage conversion techniques using commercially available and custom switching regulator circuits. Tests of these approaches are performed using the PSI46 pixel readout chip currently in use at the CMS Tracker. Performance measures of the detector electronics will include pixel noise and threshold dispersion results. Issues related to susceptibility to switching noise will be studied and presented. In this paper, we describe the current power distribution network of the CMS Tracker, study the implications of the proposed upgrade with DC-DC converters powering scheme and perform noise susceptibility analysis.

  13. Power distribution studies for CMS forward tracker

    SciTech Connect

    Todri, A.; Turqueti, M.; Rivera, R.; Kwan, S.

    2009-01-01

    The Electronic Systems Engineering Department of the Computing Division at the Fermi National Accelerator Laboratory is carrying out R&D investigations for the upgrade of the power distribution system of the Compact Muon Solenoid (CMS) Pixel Tracker at the Large Hadron Collider (LHC). Among the goals of this effort is that of analyzing the feasibility of alternative powering schemes for the forward tracker, including DC to DC voltage conversion techniques using commercially available and custom switching regulator circuits. Tests of these approaches are performed using the PSI46 pixel readout chip currently in use at the CMS Tracker. Performance measures of the detector electronics will include pixel noise and threshold dispersion results. Issues related to susceptibility to switching noise will be studied and presented. In this paper, we describe the current power distribution network of the CMS Tracker, study the implications of the proposed upgrade with DC-DC converters powering scheme and perform noise susceptibility analysis.

  14. My Game Plan: Food and Activity Tracker

    MedlinePlus

    ... MY GAME PLAN THIS WEEK… FOR CUTTING FAT GRAMS: FOR CUTTING CALORIES: FOR GETTING MORE PHYSICAL ACTIVITY: ... FOOD AND DRINK TRACKER AMOUNT /NAME /DESCRIPTION FAT GRAMS CALORIES 1/2 cup oatmeal 1 73 1 ...

  15. Search for tracker potentials in quintessence theory

    NASA Astrophysics Data System (ADS)

    Johri, Vinod B.

    2002-12-01

    We report a significant finding in quintessence theory that scalar fields with tracker potentials have a model-independent scaling behaviour in the expanding universe. So far, widely discussed exponential, power law or hyperbolic potentials can simply mimic the tracking behaviour over a limited range of redshift. A new version of the tracker field theory is proposed and it is shown that in the small redshift range where the variation of the tracking parameter ɛ may be taken to be negligible, the differential equation of generic potentials leads to hyperbolic sine and hyperbolic cosine potentials which may approximate a tracker field in the present-day universe. We have plotted the variation of the tracker potential and the equation of state of the tracker field as a function of the redshift z for the model-independent relation derived from tracker field theory; we have also plotted the variation of V(Φ) in terms of the scalar field Φ for the chosen hyperbolic cosine function and have compared it with the curves obtained by the reconstruction of V(Φ) from real observational data from the supernovae.

  16. Measurements of strangeness production in the STAR experiment at RHIC

    SciTech Connect

    Wilson, W.K.

    1995-07-15

    Simulations of the ability of the STAR (Solenoidal Tracker at RHIC) detector to measure strangeness production in central Au+Au collisions at RHIC are presented. Emphasis is placed on the reconstruction of short lived particles using a high resolution inner tracker. The prospects for performing neutral kaon interferometry are discussed. Simulation results for measurements of strange and multi-strange baryons are presented.

  17. Angular-Rate Estimation using Star Tracker Measurements

    NASA Technical Reports Server (NTRS)

    Azor, R.; Bar-Itzhack, Itzhack Y.; Deutschmann, Julie K.; Harman, Richard R.

    1999-01-01

    This paper presents algorithms for estimating the angular-rate vector of satellites using quaternion measurements. Two approaches are compared, one that uses differentiated quaternion measurements to yield coarse rate measurements which are then fed into two different estimators. In the other approach the raw quaternion measurements themselves are fed directly into the two estimators. The two estimators rely on the ability to decompose the non-linear rate dependent part of the rotational dynamics equation of a rigid body into a product of an angular-rate dependent matrix and the angular-rate vector itself. This decomposition, which is not unique, enables the treatment of the nonlinear spacecraft dynamics model as a linear one and, consequently, the application of a Pseudo-Linear Kalman Filter (PSELIKA). It also enables the application of a special Kalman filter which is based on the use of the solution of the State Dependent Algebraic Riccati Equation (SDARE) in order to compute the Kalman gain matrix and thus eliminates the need to propagate and update the filter covariance matrix. The replacement of the elaborate rotational dynamics by a simple first order Markov model is also examined. In this paper a special consideration is given to the problem of delayed quaternion measurements. Two solutions to this problem are suggested and tested. Real Rossi X-Ray Timing Explorer (RXTE) data is used to test these algorithms, and results of these tests are presented.

  18. Angular-Rate Estimation Using Star Tracker Measurements

    NASA Technical Reports Server (NTRS)

    Azor, R.; Bar-Itzhack, I.; Deutschmann, Julie K.; Harman, Richard R.

    1999-01-01

    This paper presents algorithms for estimating the angular-rate vector of satellites using quaternion measurements. Two approaches are compared, one that uses differentiated quatemion measurements to yield coarse rate measurements which are then fed into two different estimators. In the other approach the raw quatemion measurements themselves are fed directly into the two estimators. The two estimators rely on the ability to decompose the non-linear rate dependent part of the rotational dynamics equation of a rigid body into a product of an angular-rate dependent matrix and the angular-rate vector itself This decomposition, which is not unique, enables the treatment of the nonlinear spacecraft dynamics model as a linear one and, consequently, the application of a Pseudo-Linear Kalman Filter (PSELIKA). It also enables the application of a special Kalman filter which is based on the use of the solution of the State Dependent Algebraic Riccati Equation (SDARE) in order to compute the Kalman gain matrix and thus eliminates the need to propagate and update the filter covariance matrix. The replacement of the elaborate rotational dynamics by a simple first order Markov model is also examined. In this paper a special consideration is given to the problem of delayed quatemion measurements. Two solutions to this problem are suggested and tested. Real Rossi X-Ray Timing Explorer (RXTE) data is used to test these algorithms, and results of these tests are presented.

  19. Teaching with the Nightingale Tracker technology in community-based nursing education: a pilot study.

    PubMed

    Ndiwane, Abraham

    2005-01-01

    Changes in health care delivery are becoming increasingly focused on technology. Nursing students are often expected to travel long distances to suitable community sites for clinical experiences, which challenges nurse educators to design and implement instructional strategies to provide students with optimal clinical practice opportunities, while maintaining preceptor-student supervision and vital communication links. This article reports a pilot evaluation of the Nightingale Tracker system, which included both a server and an innovative, hand-held device designed to accommodate multiple forms of data input and allow timely communication between clinical faculty and students in community-based clinical settings. A sample of 5 nursing students reported that the Nightingale Tracker enhanced learning, particularly in performing and documenting physical assessments, data input and transmissions, and autonomous clinical practice. PMID:15673174

  20. SimTracker, Version 5.0

    SciTech Connect

    2004-08-27

    SimTracker is a product of the Metadata Tools subproject under the ASC Scientific Data Management effort. SimTracker is an extensible web-based application that provides the capability to view and organize large volumes of simulation data. SimTracker automatically generates metadata summaries that provide a quick overview and index to the archived results of simulations. The summaries provide access to the data sets and associated data analysis tools. They include graphical snapshots, pointers to associated simulation input and output files, and assorted annotations. The ability to add personal annotations to simulation data sets is supported. All metadata is stored in XML files suitable for searching by the generator of the data or other scientists.

  1. SimTracker, Version 5.0

    Energy Science and Technology Software Center (ESTSC)

    2004-08-27

    SimTracker is a product of the Metadata Tools subproject under the ASC Scientific Data Management effort. SimTracker is an extensible web-based application that provides the capability to view and organize large volumes of simulation data. SimTracker automatically generates metadata summaries that provide a quick overview and index to the archived results of simulations. The summaries provide access to the data sets and associated data analysis tools. They include graphical snapshots, pointers to associated simulation inputmore » and output files, and assorted annotations. The ability to add personal annotations to simulation data sets is supported. All metadata is stored in XML files suitable for searching by the generator of the data or other scientists.« less

  2. Preliminary studies of a chromaticity tracker

    SciTech Connect

    Tan, Cheng-Yang; /Fermilab

    2006-03-01

    A chromaticity tracker based on a method by D. McGinnis is proposed. This method starts with the slow modulation of the accelerating RF which causes the beam to respond to it. This beam modulation can be detected transversely with a Schottky pickup which after phase demodulation, the chromaticity can be calculated from it. However, to perform phase demodulation, the carrier frequency which is the betatron tune needs to be identified. The identification of the carrier frequency falls naturally onto the phase locked loop tune tracker which when locked to the betatron tune outputs this value in real time.

  3. Quintessence reconstructed: New constraints and tracker viability

    SciTech Connect

    Sahlen, Martin; Liddle, Andrew R.; Parkinson, David

    2007-01-15

    We update and extend our previous work reconstructing the potential of a quintessence field from current observational data. We extend the cosmological data set to include new supernova data, plus information from the cosmic microwave background and from baryon acoustic oscillations. We extend the modeling by considering Pade approximant expansions as well as Taylor series, and by using observations to assess the viability of the tracker hypothesis. We find that parameter constraints have improved by a factor of 2, with a strengthening of the preference of the cosmological constant over evolving quintessence models. Present data show some signs, though inconclusive, of favoring tracker models over nontracker models under our assumptions.

  4. Autoimmune autonomic disorders.

    PubMed

    Mckeon, Andrew; Benarroch, Eduardo E

    2016-01-01

    Autoimmune autonomic disorders occur because of an immune response directed against sympathetic, parasympathetic, and enteric ganglia, autonomic nerves, or central autonomic pathways. In general, peripheral autoimmune disorders manifest with either generalized or restricted autonomic failure, whereas central autoimmune disorders manifest primarily with autonomic hyperactivity. Some autonomic disorders are generalized, and others are limited in their anatomic extent, e.g., isolated gastrointestinal dysmotility. Historically, these disorders were poorly recognized, and thought to be neurodegenerative. Over the last 20 years a number of autoantibody biomarkers have been discovered that have enabled the identification of certain patients as having an autoimmune basis for either autonomic failure or hyperactivity. Peripheral autoimmune autonomic disorders include autoimmune autonomic ganglionopathy (AAG), paraneoplastic autonomic neuropathy, and acute autonomic and sensory neuropathy. AAG manifests with acute or subacute onset of generalized or selective autonomic failure. Antibody targeting the α3 subunit of the ganglionic-type nicotinic acetylcholine receptor (α3gAChR) is detected in approximately 50% of cases of AAG. Some other disorders are characterized immunologically by paraneoplastic antibodies with a high positive predictive value for cancer, such as antineuronal nuclear antibody, type 1 (ANNA-1: anti-Hu); others still are seronegative. Recognition of an autoimmune basis for autonomic disorders is important, as their manifestations are disabling, may reflect an underlying neoplasm, and have the potential to improve with a combination of symptomatic and immune therapies. PMID:27112689

  5. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George I.; Stetson, Howard K.

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto-Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner- TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  6. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George; Stetson, Howard

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  7. Autonomous Soaring Flight Results

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2006-01-01

    A viewgraph presentation on autonomous soaring flight results for Unmanned Aerial Vehicles (UAV)'s is shown. The topics include: 1) Background; 2) Thermal Soaring Flight Results; 3) Autonomous Dolphin Soaring; and 4) Future Plans.

  8. Autonomic Nervous System Disorders

    MedlinePlus

    Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating of your heart ... breathing and swallowing Erectile dysfunction in men Autonomic nervous system disorders can occur alone or as the result ...

  9. Autonomic Nervous System Disorders

    MedlinePlus

    Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating ... with breathing and swallowing Erectile dysfunction in men Autonomic nervous system disorders can occur alone or as ...

  10. System for star catalog equalization to enhance attitude determination

    NASA Technical Reports Server (NTRS)

    Liu, Yong (Inventor); Wu, Yeong-Wei Andy (Inventor); Li, Rongsheng (Inventor)

    2001-01-01

    An apparatus for star catalog equalization to enhance attitude determination includes a star tracker, a star catalog and a controller. The star tracker is used to sense the positions of stars and generate signals corresponding to the positions of the stars as seen in its field of view. The star catalog contains star location data that is stored using a primary and multiple secondary arrays sorted by both declination (DEC) and right ascension (RA), respectively. The star location data stored in the star catalog is predetermined by calculating a plurality of desired star locations, associating one of a plurality of stars with each of the plurality of desired star locations based upon a neighborhood association angle to generate an associated plurality of star locations: If an artificial star gap occurs during association, then the neighborhood association angle for reassociation is increased. The controller uses the star catalog to determine which stars to select to provide star measurement residuals for correcting gyroscope bias and spacecraft attitude.

  11. The Tracker of the CMS Experiment

    SciTech Connect

    Migliore, Ernesto

    2005-10-12

    With more than 200 m2 the Silicon Strip Tracker of the Compact Muon Solenoid (CMS) experiment will be the largest silicon detector ever built. In this contribution the main design considerations and the status of the construction, at about one and a half year after the begin of the production of the modules, are reviewed.

  12. jTracker and Monte Carlo Comparison

    NASA Astrophysics Data System (ADS)

    Selensky, Lauren; SeaQuest/E906 Collaboration

    2015-10-01

    SeaQuest is designed to observe the characteristics and behavior of `sea-quarks' in a proton by reconstructing them from the subatomic particles produced in a collision. The 120 GeV beam from the main injector collides with a fixed target and then passes through a series of detectors which records information about the particles produced in the collision. However, this data becomes meaningful only after it has been processed, stored, analyzed, and interpreted. Several programs are involved in this process. jTracker (sqerp) reads wire or hodoscope hits and reconstructs the tracks of potential dimuon pairs from a run, and Geant4 Monte Carlo simulates dimuon production and background noise from the beam. During track reconstruction, an event must meet the criteria set by the tracker to be considered a viable dimuon pair; this ensures that relevant data is retained. As a check, a comparison between a new version of jTracker and Monte Carlo was made in order to see how accurately jTracker could reconstruct the events created by Monte Carlo. In this presentation, the results of the inquest and their potential effects on the programming will be shown. This work is supported by U.S. DOE MENP Grant DE-FG02-03ER41243.

  13. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect

    Not Available

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  14. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  15. Experimental predictions drawn from a computational model of sign-trackers and goal-trackers

    PubMed Central

    Lesaint, Florian; Sigaud, Olivier; Clark, Jeremy J.; Flagel, Shelly B.; Khamassi, Mehdi

    2014-01-01

    Gaining a better understanding of the biological mechanisms underlying the individual variation observed in response to rewards and reward cues could help to identify and treat individuals more prone to disorders of impulsive control, such as addiction. Variation in response to reward cues is captured in rats undergoing autoshaping experiments where the appearance of a lever precedes food delivery. Although no response is required for food to be delivered, some rats (goal-trackers) learn to approach and avidly engage the magazine until food delivery, whereas other rats (sign-trackers) come to approach and engage avidly the lever. The impulsive and often maladaptive characteristics of the latter response are reminiscent of addictive behaviour in humans. In a previous article, we developed a computational model accounting for a set of experimental data regarding sign-trackers and goal-trackers. Here we show new simulations of the model to draw experimental predictions that could help further validate or refute the model. In particular, we apply the model to new experimental protocols such as injecting flupentixol locally into the core of the nucleus accumbens rather than systemically, and lesioning of the core of the nucleus accumbens before or after conditioning. In addition, we discuss the possibility of removing the food magazine during the inter-trial interval. The predictions from this revised model will help us better understand the role of different brain regions in the behaviours expressed by sign-trackers and goal-trackers. PMID:24954026

  16. Experimental predictions drawn from a computational model of sign-trackers and goal-trackers.

    PubMed

    Lesaint, Florian; Sigaud, Olivier; Clark, Jeremy J; Flagel, Shelly B; Khamassi, Mehdi

    2015-01-01

    Gaining a better understanding of the biological mechanisms underlying the individual variation observed in response to rewards and reward cues could help to identify and treat individuals more prone to disorders of impulsive control, such as addiction. Variation in response to reward cues is captured in rats undergoing autoshaping experiments where the appearance of a lever precedes food delivery. Although no response is required for food to be delivered, some rats (goal-trackers) learn to approach and avidly engage the magazine until food delivery, whereas other rats (sign-trackers) come to approach and engage avidly the lever. The impulsive and often maladaptive characteristics of the latter response are reminiscent of addictive behaviour in humans. In a previous article, we developed a computational model accounting for a set of experimental data regarding sign-trackers and goal-trackers. Here we show new simulations of the model to draw experimental predictions that could help further validate or refute the model. In particular, we apply the model to new experimental protocols such as injecting flupentixol locally into the core of the nucleus accumbens rather than systemically, and lesioning of the core of the nucleus accumbens before or after conditioning. In addition, we discuss the possibility of removing the food magazine during the inter-trial interval. The predictions from this revised model will help us better understand the role of different brain regions in the behaviours expressed by sign-trackers and goal-trackers. PMID:24954026

  17. Genetic autonomic disorders.

    PubMed

    Axelrod, Felicia B

    2013-03-01

    Genetic disorders affecting the autonomic nervous system can result in abnormal development of the nervous system or they can be caused by neurotransmitter imbalance, an ion-channel disturbance or by storage of deleterious material. The symptoms indicating autonomic dysfunction, however, will depend upon whether the genetic lesion has disrupted peripheral or central autonomic centers or both. Because the autonomic nervous system is pervasive and affects every organ system in the body, autonomic dysfunction will result in impaired homeostasis and symptoms will vary. The possibility of genetic confirmation by molecular testing for specific diagnosis is increasing but treatments tend to remain only supportive and directed toward particular symptoms. PMID:23465768

  18. The autonomic laboratory

    NASA Technical Reports Server (NTRS)

    Low, P. A.; Opfer-Gehrking, T. L.

    1999-01-01

    The autonomic nervous system can now be studied quantitatively, noninvasively, and reproducibly in a clinical autonomic laboratory. The approach at the Mayo Clinic is to study the postganglionic sympathetic nerve fibers of peripheral nerve (using the quantitative sudomotor axon reflex test [QSART]), the parasympathetic nerves to the heart (cardiovagal tests), and the regulation of blood pressure by the baroreflexes (adrenergic tests). Patient preparation is extremely important, since the state of the patient influences the results of autonomic function tests. The autonomic technologist in this evolving field needs to have a solid core of knowledge of autonomic physiology and autonomic function tests, followed by training in the performance of these tests in a standardized fashion. The range and utilization of tests of autonomic function will likely continue to evolve.

  19. Pure Autonomic Failure.

    PubMed

    Thaisetthawatkul, Pariwat

    2016-08-01

    Pure autonomic failure (PAF) is a rare sporadic neurodegenerative autonomic disorder characterized by slowly progressive pan autonomic failure without other features of neurologic dysfunctions. The main clinical symptoms result from neurogenic orthostatic hypotension and urinary and gastrointestinal autonomic dysfunctions. Autonomic failure in PAF is caused by neuronal degeneration of pre- and postganglionic sympathetic and parasympathetic neurons in the thoracic spinal cord and paravertebral autonomic ganglia. The presence of Lewy bodies and α-synuclein deposits in these neural structures suggests that PAF is one of Lewy body synucleinopathies, examples of which include multiple system atrophy, Parkinson disease, and Lewy body disease. There is currently no specific treatment to stop progression in PAF. Management of autonomic symptoms is the mainstay of treatment and includes management of orthostatic hypotension and supine hypertension. The prognosis for survival of PAF is better than for the other synucleinopathies. PMID:27338613

  20. Research and development on embedded omnidirectional vision tracker for vision navigation

    NASA Astrophysics Data System (ADS)

    Zhu, Junchao; Feng, Weijia; Cao, Zuoliang; Zhang, Baofeng

    2009-11-01

    Omni-directional vision appears the definite significance since its advantage of acquiring all vision information simultaneously. In this paper, an integrated omni-directional vision tracker based on the configuration with CMOS, FPGA and DSP has been implemented. Fisheye lens is one of the most efficient ways to establish omni-directional vision systems, however, it appear with an unavoidable inherent distortion. An imaging system model which consists of fisheye-lens and the embedded tracker has been proposed. A novel beacon owning the feature of particular topology shape can be identified by the appropriative recognition processes. Particle filter has been programmed as an intersectional arithmetic structure which processes the same step of several particle filters simultaneously. We called it as Multiple Intersection Particle Filter. MIPF makes multi-targets tracking efficiently and successfully on embedded platform. A rectification technique based on equidistant projection theorem is used for correction some distorted image point. The localization method just employs the picture position of two objects to estimate the space position and orientation for AGV. After target recognition, vision tracking, rectification, and object positioning functions actualized on the embedded omni-directional vision tracker, autonomous navigation has been demonstrated on experimental AGV.

  1. Optical model and calibration of a sun tracker

    NASA Astrophysics Data System (ADS)

    Volkov, Sergei N.; Samokhvalov, Ignatii V.; Cheong, Hai Du; Kim, Dukhyeon

    2016-09-01

    Sun trackers are widely used to investigate scattering and absorption of solar radiation in the Earth's atmosphere. We present a method for optimization of the optical altazimuth sun tracker model with output radiation direction aligned with the axis of a stationary spectrometer. The method solves the problem of stability loss in tracker pointing at the Sun near the zenith. An optimal method for tracker calibration at the measurement site is proposed in the present work. A method of moving calibration is suggested for mobile applications in the presence of large temperature differences and errors in the alignment of the optical system of the tracker.

  2. The CDF online Silicon Vertex Tracker

    NASA Astrophysics Data System (ADS)

    Ashmanskas, W.; Bardi, A.; Bari, M.; Belforte, S.; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culbertson, R.; Dell'Orso, M.; Donati, S.; Fiori, I.; Frisch, H. J.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Moneta, L.; Morsani, F.; Nakaya, T.; Passuello, D.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Wu, X.; Yang, U.; Zanello, L.; Zanetti, A. M.

    2002-06-01

    The CDF Online Silicon Vertex Tracker (SVT) reconstructs 2D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker (XFT). The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II.

  3. The CDF online silicon vertex tracker

    SciTech Connect

    W. Ashmanskas et al.

    2001-11-02

    The CDF Online Silicon Vertex Tracker reconstructs 2-D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast Tracker. The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B{sub s} mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II.

  4. Target for optically activated seekers and trackers

    NASA Astrophysics Data System (ADS)

    Lakin, C. T.; Willett, N. F.

    1984-05-01

    This abstract discloses a target for optically activated seekers and trackers (TOAST) which provides for calibrated and variable target characteristics such as size, intensity, spatial position, color and interfering background. The TOAST has a first ilumination system providing a target light beam through an adjustable iris which controls image size. The target beam passes through a collimator lens which focuses the light at infinity. With the target beam focused at infinity, the motion of an elevation plate lengthens or shortens the distance from the collimator lens to a one motion mirror. The target beam is attenuated by a variable filter driven by a servo-motor, and a color selection process is provided by passing the beam through spectral filters. A background light beam with background imagery is provided to the beamsplitter mirror and mixed with the target image so as to simulate the target environment encountered by an operating optically activated seeker and tracker.

  5. Upgrade of the Upstream Tracker at LHCb

    NASA Astrophysics Data System (ADS)

    Andrews, Jason; LHCb Collaboration

    2015-04-01

    The LHCb detector will be upgraded to allow it operate at higher collider luminosity without the need for a hardware trigger stage. Flavor enriched events will be selected in a software based, high level trigger, using fully reconstructed events. This presentation will describe the design, optimization and the expected performance of the Upstream Tracker (UT), which has a critical role in high level trigger scheme.

  6. Accuracy of the vivofit activity tracker.

    PubMed

    Alsubheen, Sana'a A; George, Amanda M; Baker, Alicia; Rohr, Linda E; Basset, Fabien A

    2016-08-01

    The purpose of this study was to examine the accuracy of the vivofit activity tracker in assessing energy expenditure and step count. Thirteen participants wore the vivofit activity tracker for five days. Participants were required to independently perform 1 h of self-selected activity each day of the study. On day four, participants came to the lab to undergo BMR and a treadmill-walking task (TWT). On day five, participants completed 1 h of office-type activities. BMR values estimated by the vivofit were not significantly different from the values measured through indirect calorimetry (IC). The vivofit significantly underestimated EE for treadmill walking, but responded to the differences in the inclination. Vivofit underestimated step count for level walking but provided an accurate estimate for incline walking. There was a strong correlation between EE and the exercise intensity. The vivofit activity tracker is on par with similar devices and can be used to track physical activity. PMID:27266422

  7. The CMS Tracker Detector Control System

    NASA Astrophysics Data System (ADS)

    Yousaf Shah, S.; Tsirou, Andromachi; Verdini, Piero Giorgio; Hartmann, Frank; Masetti, Lorenzo; Dirkes, Guido H.; Stringer, Robert; Fahrer, Manuel

    2009-06-01

    The Compact Muon Solenoid DCS (CMS) Silicon Strip Tracker is by far the largest detector ever built in micro-strip technology. It has an active surface area of 198 m 2 consisting of 15,148 silicon modules with 9,316,352 readout channels read via 75,376 Analog Pipeline Voltage (APV) front-end chips and a total of 24,244 sensors. The Detector Control System (DCS) for the Tracker is a distributed control system that operates ˜2000 power supplies for the silicon modules and also monitors its environmental sensors. The DCS receives information from about 10 3 environmental probes (temperature and humidity sensors) located inside the detector's volume and values from these probes are driven through the Programmable Logic Controllers (PLC) of the Detector Safety System (DSS). A total of 10 5 parameters are read out from the dedicated chips in the front-end electronics of the detector via the data acquisition system, and a total of 10 5 parameters are read from the power supply modules. All these parameters are monitored, evaluated and correlated with the detector layout; actions are taken under specific conditions. The hardware for DCS consists of 10 PCs and 10 PLC systems that are continuously running the necessary control and safety routines. The DCS is a fundamental tool for the Tracker operation and its safety.

  8. Stars and star systems

    NASA Astrophysics Data System (ADS)

    Martynov, D. Ia.

    Topics examined include close binary systems, supernovae and their remnants, variable stars, young star groups (e.g., clusters and associations), spherical star clusters, and planetary nebulae. Also considered are the interstellar medium and star formation, systems of galaxies, and current problems in cosmology.

  9. Autonomous satellite navigation by stellar refraction

    NASA Technical Reports Server (NTRS)

    Gounley, R.; White, R.; Gai, E.

    1983-01-01

    This paper describes an error analysis of an autonomous navigator using refraction measurements of starlight passing through the upper atmosphere. The analysis is based on a discrete linear Kalman filter. The filter generated steady-state values of navigator performance for a variety of test cases. Results of these simulations show that in low-earth orbit position-error standard deviations of less than 0.100 km may be obtained using only 40 star sightings per orbit.

  10. Pediatric autonomic disorders.

    PubMed

    Axelrod, Felicia B; Chelimsky, Gisela G; Weese-Mayer, Debra E

    2006-07-01

    The scope of pediatric autonomic disorders is not well recognized. The goal of this review is to increase awareness of the expanding spectrum of pediatric autonomic disorders by providing an overview of the autonomic nervous system, including the roles of its various components and its pervasive influence, as well as its intimate relationship with sensory function. To illustrate further the breadth and complexities of autonomic dysfunction, some pediatric disorders are described, concentrating on those that present at birth or appear in early childhood. PMID:16818580

  11. Robust visual tracking with dual spatio-temporal context trackers

    NASA Astrophysics Data System (ADS)

    Sun, Shiyan; Zhang, Hong; Yuan, Ding

    2015-12-01

    Visual tracking is a challenging problem in computer vision. Recent years, significant numbers of trackers have been proposed. Among these trackers, tracking with dense spatio-temporal context has been proved to be an efficient and accurate method. Other than trackers with online trained classifier that struggle to meet the requirement of real-time tracking task, a tracker with spatio-temporal context can run at hundreds of frames per second with Fast Fourier Transform (FFT). Nevertheless, the performance of the tracker with Spatio-temporal context relies heavily on the learning rate of the context, which restricts the robustness of the tracker. In this paper, we proposed a tracking method with dual spatio-temporal context trackers that hold different learning rate during tracking. The tracker with high learning rate could track the target smoothly when the appearance of target changes, while the tracker with low learning rate could percepts the occlusion occurring and continues to track when the target starts to emerge again. To find the target among the candidates from these two trackers, we adopt Normalized Correlation Coefficient (NCC) to evaluate the confidence of each sample. Experimental results show that the proposed algorithm performs robustly against several state-of-the-art tracking methods.

  12. A coherent frequency-bearing tracker

    NASA Astrophysics Data System (ADS)

    Ohlms, D. E.; Cohen, A. O.; Hampton, M. L.; Johnson, G. W.

    The passive measurement of target bearing can be achieved by estimating the phase difference between spatially separated observations of a narrow-band signal. The estimation of this phase difference requires algorithms to track variations in received frequency and the phase difference. This paper presents such an algorithm: a coherently coupled frequency-bearing tracker (CCFBT). The CCFBT is derived from extended Kalman filter theory. A linearized covariance analysis predicts performance above threshold, and an approximate rule predicts threshold. Simulation results verify the covariance analysis and threshold predictions.

  13. Babar Silicon Vertex Tracker: Status and Prospects

    SciTech Connect

    Re, V.; Bondioli, M.; Bruinsma, M.; Curry, S.; Kirkby, D.; Berryhill, J.; Burke, S.; Callahan, D.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hale, D.; Kyre, S.; Richman, J.; Stoner, J.; Verkerke, W.; Beck, T.; Eisner, A.M.; Kroseberg, J.; Lockman, W.S.; Nesom, G.; /INFN, Pavia /Pavia U. /UC, Irvine /UC, Santa Barbara /UC, Santa Cruz /INFN, Ferrara /Ferrara U. /LBL, Berkeley /Maryland U. /INFN, Milan /Milan U. /NIKHEF, Amsterdam /INFN, Pisa /Pisa U. /Princeton U. /UC, Riverside /SLAC /INFN, Turin /Turin U. /INFN, Trieste /Trieste U.

    2006-04-27

    The BABAR Silicon Vertex Tracker (SVT) has been efficiently operated for six years since the start of data taking in 1999. Due to higher than expected background levels some unforeseen effects have appeared. We discuss: a shift in the pedestal for the channels of the AToM readout chips that are most exposed to radiation; an anomalous increase in the bias leakage current for the modules in the outer layers. Estimates of future radiation doses and occupancies are shown together with the extrapolated detector performance and lifetime, in light of the new observations.

  14. STAR cluster-finder ASIC

    SciTech Connect

    Botlo, M.; LeVine, M.J.; Scheetz, R.A.

    1997-12-31

    The STAR experiment reads out a TPC and an SVT (silicon vertex tracker), both of which require in-line pedestal subtraction, compression of ADC values from 10-bit to 8-bit, and location of time sequences representing responses to charged-particle tracks. The STAR cluster finder ASIC responds to all of these needs. Pedestal subtraction and compression are performed using lookup tables in attached RAM. We describe its design and implementation, as well as testing methodology and results of tests performed on foundry prototypes.

  15. Success potential of automated star pattern recognition

    NASA Technical Reports Server (NTRS)

    Van Bezooijen, R. W. H.

    1986-01-01

    A quasi-analytical model is presented for calculating the success probability of automated star pattern recognition systems for attitude control of spacecraft. The star data is gathered by an imaging star tracker (STR) with a circular FOV capable of detecting 20 stars. The success potential is evaluated in terms of the equivalent diameters of the FOV and the target star area ('uniqueness area'). Recognition is carried out as a function of the position and brightness of selected stars in an area around each guide star. The success of the system is dependent on the resultant pointing error, and is calculated by generating a probability distribution of reaching a threshold probability of an unacceptable pointing error. The method yields data which are equivalent to data available with Monte Carlo simulatins. When applied to the recognition system intended for use on the Space IR Telescope Facility it is shown that acceptable pointing, to a level of nearly 100 percent certainty, can be obtained using a single star tracker and about 4000 guide stars.

  16. A multi-hypothesis tracker for clicking whales.

    PubMed

    Baggenstoss, Paul M

    2015-05-01

    This paper describes a tracker specially designed to track clicking beaked whales using widely spaced bottom-mounted hydrophones, although it can be adapted to different species and sensors. The input to the tracker is a sequence of static localization solutions obtained using time difference of arrival information at widely spaced hydrophones. To effectively handle input localizations with high ambiguity, the tracker is based on multi-hypothesis tracker concepts, so it considers all potential association hypotheses and keeps a large number of potential tracks in memory. The method is demonstrated on actual data and shown to successfully track multiple beaked whales at depth. PMID:25994688

  17. Videometric head tracker for augmented reality applications

    NASA Astrophysics Data System (ADS)

    Janin, Adam L.; Zikan, Karel; Mizell, David; Banner, Mike; Sowizral, Henry A.

    1995-12-01

    For the past three years, we have been developing augmented reality technology for application to a variety of touch labor tasks in aircraft manufacturing and assembly. The system would be worn by factory workers to provide them with better-quality information for performing their tasks than was previously available. Using a see-through head-mounted display (HMD) whose optics are set at a focal length of about 18 in., the display and its associated head tracking system can be used to superimpose and stabilize graphics on the surface of a work piece. This technology would obviate many expensive marking systems now used in aerospace manufacturing. The most challenging technical issue with respect to factory applications of AR is head position and orientation tracking. It requires high accuracy, long- range tracking in a high-noise environment. The approach we have chosen uses a head- mounted miniature video camera. The user's wearable computer system utilizes the camera to find fiducial markings that have been placed on known coordinates on or near the work piece. The system then computes the user's position and orientation relative to the fiducial marks. It is referred to as a `videometric' head tracker. In this paper, we describe the steps we took and the results we obtained in the process of prototyping our videometric head tracker, beginning with analytical and simulation results, and continuing through the working prototypes.

  18. Autonomous surveillance for biosecurity.

    PubMed

    Jurdak, Raja; Elfes, Alberto; Kusy, Branislav; Tews, Ashley; Hu, Wen; Hernandez, Emili; Kottege, Navinda; Sikka, Pavan

    2015-04-01

    The global movement of people and goods has increased the risk of biosecurity threats and their potential to incur large economic, social, and environmental costs. Conventional manual biosecurity surveillance methods are limited by their scalability in space and time. This article focuses on autonomous surveillance systems, comprising sensor networks, robots, and intelligent algorithms, and their applicability to biosecurity threats. We discuss the spatial and temporal attributes of autonomous surveillance technologies and map them to three broad categories of biosecurity threat: (i) vector-borne diseases; (ii) plant pests; and (iii) aquatic pests. Our discussion reveals a broad range of opportunities to serve biosecurity needs through autonomous surveillance. PMID:25744760

  19. An advanced tracker design for pointing and control of space vehicles using the charge injection device

    NASA Technical Reports Server (NTRS)

    Jones, C.; Kollodge, J. C.

    1982-01-01

    The use of charge transfer devices (CTD) in pointing and control of space vehicles is examined, with emphasis on the use of charge injection devices (CID). The selection of CTD type and CID operation, including CID signal and noise analysis and signal improvement, are discussed. Star tracking operational advantages of the CTD are pointed out, and the tracking optical concept is discussed and graphically depicted. The position interpolation procedure and the effects of rate of stellar motion on position interpolation are considered, and error analysis is examined. Finally, the breadboard and test program are discussed in detail, coarse and fine acquisition, test for star, track pattern, test procedure and results. An overall accuracy performance of approximately 0.02 pixels or approximately 0.8 arcsec for the test equipment and tracker was obtained.

  20. Visible-spectrum remote eye tracker for gaze communication

    NASA Astrophysics Data System (ADS)

    Imabuchi, Takashi; Prima, Oky Dicky A.; Kikuchi, Hikaru; Horie, Yusuke; Ito, Hisayoshi

    2015-03-01

    Many approaches have been proposed to create an eye tracker based on visible-spectrum. These efforts provide a possibility to create inexpensive eye tracker capable to operate outdoor. Although the resulted tracking accuracy is acceptable for a visible-spectrum head-mounted eye tracker, there are many limitations of these approaches to create a remote eye tracker. In this study, we propose a high-accuracy remote eye tracker that uses visible-spectrum imaging and several gaze communication interfaces suited to the tracker. The gaze communication interfaces are designed to assist people with motor disability. Our results show that the proposed eye tracker achieved an average accuracy of 0.77° and a frame rate of 28 fps with a personal computer. With a tablet device, the proposed eye tracker achieved an average accuracy of 0.82° and a frame rate of 25 fps. The proposed gaze communication interfaces enable users to type a complete sentence containing eleven Japanese characters in about a minute.

  1. SVT: an online silicon vertex tracker for the CDF upgrade

    SciTech Connect

    Bardi, A.; Belforte, S.; Berryhill, J.; CDF Collaboration

    1997-07-01

    The SVT is an online tracker for the CDF upgrade which will reconstruct 2D tracks using information from the Silicon VerteX detector (SVXII) and Central Outer Tracker (COT). The precision measurement of the track impact parameter will then be used to select and record large samples of B hadrons. We discuss the overall architecture, algorithms, and hardware implementation of the system.

  2. Laser tracker error determination using a network measurement

    NASA Astrophysics Data System (ADS)

    Hughes, Ben; Forbes, Alistair; Lewis, Andrew; Sun, Wenjuan; Veal, Dan; Nasr, Karim

    2011-04-01

    We report on a fast, easily implemented method to determine all the geometrical alignment errors of a laser tracker, to high precision. The technique requires no specialist equipment and can be performed in less than an hour. The technique is based on the determination of parameters of a geometric model of the laser tracker, using measurements of a set of fixed target locations, from multiple locations of the tracker. After fitting of the model parameters to the observed data, the model can be used to perform error correction of the raw laser tracker data or to derive correction parameters in the format of the tracker manufacturer's internal error map. In addition to determination of the model parameters, the method also determines the uncertainties and correlations associated with the parameters. We have tested the technique on a commercial laser tracker in the following way. We disabled the tracker's internal error compensation, and used a five-position, fifteen-target network to estimate all the geometric errors of the instrument. Using the error map generated from this network test, the tracker was able to pass a full performance validation test, conducted according to a recognized specification standard (ASME B89.4.19-2006). We conclude that the error correction determined from the network test is as effective as the manufacturer's own error correction methodologies.

  3. Optimization of the silicon sensors for the CMS tracker

    NASA Astrophysics Data System (ADS)

    Albergo, S.; Angarano, M.; Azzi, P.; Babucci, E.; Bacchetta, N.; Bader, A.; Bagliesi, G.; Basti, A.; Biggeri, U.; Biino, C.; Bilei, G. M.; Bisello, D.; Boemi, D.; Bosi, F.; Borello, L.; Braibant, S.; Breuker, H.; Brunetti, M. T.; Bruzzi, M.; Buffini, A.; Busoni, S.; Candelori, A.; Caner, A.; Castaldi, R.; Castro, A.; Catacchini, E.; Checcucci, B.; Ciampolini, P.; Civinini, C.; Costa, M.; Creanza, D.; D'Alessandro, R.; DeMaria, N.; de Palma, M.; Dell'Orso, R.; Dutta, S.; Favro, G.; Fiore, L.; Focardi, E.; French, M.; Freudenreich, K.; Frey, A.; Friedl, M.; Fürtjes, A.; Giassi, A.; Giorgi, M.; Giraldo, A.; Glessing, W.; Gu, W. H.; Hall, G.; Hammarstrom, R.; Hebbeker, T.; Honkanen, A.; Honma, A.; Hrubec, J.; Huhtinen, M.; Kaminsky, A.; Karimaki, V.; Koenig, St.; Krammer, M.; Lariccia, P.; Lenzi, M.; Loreti, M.; Luebelsmeyer, K.; Lustermann, W.; Mättig, P.; Maggi, G.; Mannelli, M.; Mantovani, G.; Marchioro, A.; Mariotti, C.; Martignon, G.; Mc Evoy, B.; Meschini, M.; Messineo, A.; Migliore, E.; My, S.; Neviani, A.; Paccagnella, A.; Palla, F.; Pandoulas, D.; Papi, A.; Parrini, G.; Passeri, D.; Pernicka, M.; Pieri, M.; Piperov, S.; Potenza, R.; Radicci, V.; Raffaelli, F.; Raymond, M.; Rizzo, F.; Santocchia, A.; Segneri, G.; Selvaggi, G.; Servoli, L.; Sguazzoni, G.; Siedling, R.; Silvestris, L.; Starodumov, A.; Stavitski, I.; Surrow, B.; Tempesta, P.; Tonelli, G.; Tricomi, A.; Tuominiemi, J.; Tuuva, T.; Verdini, P. G.; Viertel, G.; Xie, Z.; Yahong, Li; Watts, S.; Wittmer, B.

    2001-07-01

    The CMS experiment at the LHC will comprise a large silicon strip tracker. This article highlights some of the results obtained in the R&D studies for the optimization of its silicon sensors. Measurements of the capacitances and of the high voltage stability of the devices are presented before and after irradiation to the dose expected after the full lifetime of the tracker.

  4. Charge-Coupled Device (CCD) Trackers For High-Accuracy Guidance Applications

    NASA Astrophysics Data System (ADS)

    Salomon, Phil M.

    1981-02-01

    Recent advances in large area charge-coupled device (CCD) imaging detectors and high-speed microprocessors have prompted the development of a new clss of electro-optical tracking instruments at the Jet Propulsion Labora-tory (JPL). These instruments are designed for standardized NASA-wide usage and are characterized by their extremely high pointing accuracy and stability and performance capabilities which are largely software defined and thus easily adapted to a variety of mission requirements. This paper presents an examination of the methods by which CCD detectors are being incorporated in star tracker instruments and the performance capabilities that can be expected from currently available devices. The multi-function sensor concept, in which a single sensor can function in a variety of guidance applications, is described. Software algorithms designed to provide efficient extraction of guidance information from both point and extended images are also presented. CCD star tracker implementations currently underway at JPL are described, and perfor-mance data obtained during laboratory testing are presented and discussed.

  5. Charge-coupled device /CCD/ trackers for high accuracy guidance applications

    NASA Technical Reports Server (NTRS)

    Salomon, P. M.

    1979-01-01

    Recent advances in large area charge coupled device (CCD) imaging detectors and high speed microprocessors have prompted the development of a new class of electro-optical tracking instruments at the Jet Propulsion Laboratory (JPL). These instruments are designed for standardized NASA-wide usage and are characterized by their extremely high pointing accuracy and stability and performance capabilities which are largely software defined and thus easily adapted to a variety of mission requirements. This paper presents an examination of the methods by which CCD detectors are being incorporated in star tracker instruments and the performance capabilities that can be expected from currently available devices. The multi-function sensor concept, in which a single sensor can function in a variety of guidance applications, is described. Software algorithms designed to provide efficient extraction of guidance information from both point and extended images are also presented. CCD star tracker implementations currently underway at JPL are described, and performance data obtained during laboratory testing is presented and discussed.

  6. Highly Autonomous Systems Workshop

    NASA Technical Reports Server (NTRS)

    Doyle, R.; Rasmussen, R.; Man, G.; Patel, K.

    1998-01-01

    It is our aim by launching a series of workshops on the topic of highly autonomous systems to reach out to the larger community interested in technology development for remotely deployed systems, particularly those for exploration.

  7. Infrared tracker for a portable missile launcher

    SciTech Connect

    Carlson, J.J.

    1993-07-13

    An infrared beam tracker is described for arrangement to a housing that is unitary with a portable missile launcher, comprising: a rotating beam splitter positioned to intercept the infrared beam passing a first portion of the beam through the beam splitter along a first direction and reflecting the remaining portion along a different direction; a first infrared detector for receiving the beam reflected portion from the beam splitter and produce electric signals responsive thereto; a second infrared detector for receiving the beam portion that passes through the beam splitter and providing electric signals responsive thereto; and means interconnected to the first and second infrared detectors and responsive to the electric signals generated by said detectors for determining errors in missile flight direction and communicating course correction information to the missile.

  8. 3D Technology for intelligent trackers

    SciTech Connect

    Lipton, Ronald; /Fermilab

    2010-09-01

    At Super-LHC luminosity it is expected that the standard suite of level 1 triggers for CMS will saturate. Information from the tracker will be needed to reduce trigger rates to satisfy the level 1 bandwidth. Tracking trigger modules which correlate information from closely-spaced sensor layers to form an on-detector momentum filter are being developed by several groups. We report on a trigger module design which utilizes three dimensional integrated circuit technology incorporating chips which are connected both to the top and bottom sensor, providing the ability to filter information locally. A demonstration chip, the VICTR, has been submitted to the Chartered/Tezzaron two-tier 3D run coordinated by Fermilab. We report on the 3D design concept, the status of the VICTR chip and associated sensor integration utilizing oxide bonding.

  9. Generic evaluation tracker database for OTH radar

    NASA Astrophysics Data System (ADS)

    Flanders, Lorraine E.; Hartnett, Michael P.; Vannicola, Vincent C.

    1999-10-01

    This paper provides a real world target and clutter model for evaluation of radar signal processing algorithms. The procedure is given for target and clutter data collection which is then followed by the equalization and superposition method. We show how the model allows one to vary the target signal to clutter noise ratio so that system performance may be assessed over a wide range of target amplitudes, i.e. detection probability versus target signal to noise ratio. Three candidate pre-track algorithms are evaluated and compared using this model as input in conjunction with an advanced tracker algorithm as a post processor. Data used for the model represents airborne traffic operating over the body of water bounded by North, Central, and South America. The processors relate to the deployment of Over the Horizon Radar for drug interdiction. All the components of this work, model as well as the processors, are in software.

  10. Autonomous Flight Safety System

    NASA Technical Reports Server (NTRS)

    Simpson, James

    2010-01-01

    The Autonomous Flight Safety System (AFSS) is an independent self-contained subsystem mounted onboard a launch vehicle. AFSS has been developed by and is owned by the US Government. Autonomously makes flight termination/destruct decisions using configurable software-based rules implemented on redundant flight processors using data from redundant GPS/IMU navigation sensors. AFSS implements rules determined by the appropriate Range Safety officials.

  11. Diabetic autonomic neuropathy.

    PubMed

    Clarke, B F; Ewing, D J; Campbell, I W

    1979-10-01

    This review attempts to outline the present understanding of diabetic autonomic neuropathy. The clinical features have been increasinly recognised but knowledge of the localization and morphology of the lesions and their pathogenesis remains fragmentary. A metabolic causation as postulated in somatic nerves accords best with clinical observations. Most bodily systems, particularly the cardiovascular, gastrointestinal and urogenital, are involved with added disturbances of thermoregulatory function and pupillary reflexes. Possible effects on neuroendocrine and peptidergic secretion and respiratory control await definition. Current interest centres around the development of a new generation of tests of autonomic nerve function that are simple, non-invasive, reproducible and allow precision in diagnosis and accurate quantitation. Most are based on cardiovascular reflexes and abnormality in them is assumed to reflect autonomic damage elsewhere. Probably no single test suffices and a battery of tests reflecting both parasympathetic and sympathetic function is preferable. Little is known of the natural history. The prevalence may be greater than previously suspected and although symptoms are mild in the majority, a few develop florid features. The relation of control and duration of diabetes to the onset and progression of autonomic neuropathy is not clearly established. Once tests of autonomic function become abnormal they usually remain abnormal. Symptomatic autonomic neuropathy carries a greatly increased mortality rate possibly due to indirect mechanisms such as renal failure and direct mechanisms such as cardio-resiratory arrest. Improved treatment of some of the more disabling symptoms has been possible in recent years. PMID:387501

  12. The STAR cluster-finder ASIC

    SciTech Connect

    Botlo, M.; LeVine, M.J.; Scheetz, R.A.; Schulz, M.W.; Short, P.; Woods, J.; Crosetto, D.

    1997-12-01

    STAR is a large TPC-based experiment at RHIC, the relativistic heavy ion collider at Brookhaven National Laboratory. The STAR experiment reads out a TPC and an SVT (silicon vertex tracker), both of which require in-line pedestal subtraction, compression of ADC values from 10-bit to 8-bit, and location of time sequences representing responses to charged-particle tracks. The STAR cluster finder ASIC responds to all of these needs. Pedestal subtraction and compression are performed using lookup tables in attached RAM. The authors describe its design and implementation, as well as testing methodology and results of tests performed on foundry prototypes.

  13. THE STAR OFFLINE FRAMEWORK.

    SciTech Connect

    FINE,V.; FISYAK,Y.; PEREVOZTCHIKOV,V.; WENAUS,T.

    2000-02-07

    The Solenoidal Tracker At RHIC (STAR) is a-large acceptance collider detector, commissioned at Brookhaven National Laboratory in 1999. STAR has developed a software framework supporting simulation, reconstruction and analysis in offline production, interactive physics analysis and online monitoring environments that is well matched both to STAR's present status of transition between Fortran and C++ based software and to STAR's evolution to a fully OO software base. This paper presents the results of two years effort developing a modular C++ framework based on the ROOT package that encompasses both wrapped Fortran components (legacy simulation and reconstruction code) served by IDL-defined data structures, and fully OO components (all physics analysis code) served by a recently developed object model for event data. The framework supports chained components, which can themselves be composite subchains, with components (''makers'') managing ''data sets'' they have created and are responsible for. An St-DataSet class from which data sets and makers inherit allows the construction of hierarchical organizations of components and data, and centralizes almost all system tasks such as data set navigation, I/O, database access, and inter-component communication. This paper will present an overview of this system, now deployed and well exercised in production environments with real and simulated data, and in an active physics analysis development program.

  14. Formation of star tracking reticles

    NASA Technical Reports Server (NTRS)

    Smith, W. O.; Toft, A. R. (Inventor)

    1974-01-01

    The present application is directed towards a process for producing high resolution, substantially non-reflective reticles or choppers suitable for use for transmitting in both the visible and near ultra-violet regions, able to withstand reasonable handling and extreme environmental conditions, and capable of operating at speeds of from 2800 to about 9000 revolutions per minute without distortion. In particular, the present invention is directed towards the production or reticles having a quartz base vacuum coated with chromium, chromium-silver alloy, and silver with electrodeposited copper and black chromium thereon, respectively, in the form of a reticle pattern. The quartz permits the transmission of light while the pattern is opaque to light. The reticles of the present invention are intended for use in optical trackers, such as star trackers used in outer space.

  15. Thinking Ahead: Autonomic Buildings

    SciTech Connect

    Brambley, Michael R. )

    2002-08-31

    The time has come for the commercial buildings industries to reconsider the very nature of the systems installed in facilities today and to establish a vision for future buildings that differs from anything in the history of human shelter. Drivers for this examination include reductions in building operation staffs; uncertain costs and reliability of electric power; growing interest in energy-efficient and resource-conserving?green? and?high-performance? commercial buildings; and a dramatic increase in security concerns since the tragic events of September 11. This paper introduces a new paradigm? autonomic buildings? which parallels the concept of autonomic computing, introduced by IBM as a fundamental change in the way computer networks work. Modeled after the human nervous system,?autonomic systems? themselves take responsibility for a large portion of their own operation and even maintenance. For commercial buildings, autonomic systems could provide environments that afford occupants greater opportunity to focus on the things we do in buildings rather than on operation of the building itself, while achieving higher performance levels, increased security, and better use of energy and other natural resources. The author uses the human body and computer networking to introduce and illustrate this new paradigm for high-performance commercial buildings. He provides a vision for the future of commercial buildings based on autonomicity, identifies current research that could contribute to this future, and highlights research and technological gaps. The paper concludes with a set of issues and needs that are key to converting this idealized future into reality.

  16. Pure autonomic failure.

    PubMed

    Garland, Emily M; Hooper, William B; Robertson, David

    2013-01-01

    A 1925 report by Bradbury and Eggleston first described patients with extreme orthostatic hypotension and a low, steady heart rate. Evidence accumulated over the next two decades that patients with orthostatic hypotension include those with pure autonomic failure (PAF), characterized by isolated peripheral autonomic dysfunction and decreased norepinephrine synthesis; multiple system atrophy (MSA) with symptoms of a central Parkinson-like syndrome and normal resting plasma norepinephrine; and Parkinson's disease (PD), with lesions in postganglionic noradrenergic neurons and signs of autonomic dysfunction. All three disorders are classified as α-synucleinopathies. Insoluble deposits of α-synuclein are found in glia in MSA, whereas they take the form of neuronal cytoplasmic inclusions called Lewy bodies in PAF and PD. The exact relationship between α-synuclein deposits and the pathology remains undetermined. PAF occurs sporadically, and progresses slowly with a relatively good prognosis. However, it has been proposed that some cases of PAF may develop a central neurodegenerative disorder. Differentiation between PAF, MSA, and PD with autonomic failure can be facilitated by a number of biochemical and functional tests and by imaging studies. Cardiac sympathetic innervation is generally intact in MSA but decreased or absent in Parkinson's disease with autonomic failure and PAF. Treatment of PAF is directed at relieving symptoms with nonpharmacological interventions and with medications producing volume expansion and vasoconstriction. Future studies should focus on determining the factors that lead to central rather than solely peripheral neurodegeneration. PMID:24095130

  17. New technologies in the D0 central tracker upgrade

    SciTech Connect

    Lincoln, D.; D0 Collaboration

    1996-06-01

    The D0 collaboration has undertaken an aggressive upgrade of its central tracking system. The existing tracker will be completely removed and replaced by a two Tesla superconducting solenoidal magnet, an 837 000 channel silicon vertex system, and 80 000 channel scintillating fiber tracker, followed by a 7 680 channel central preshower detector and a 16 000 channel forward preshower detector. In this paper the author discusses all of the subsystems of the D0 central tracker upgrade, but will emphasize those aspects which involve new technology: radiation hard scintillating fiber, VLPC`s and extruded scintillating strips.

  18. Status of the D0 fiber tracker and preshower detectors

    SciTech Connect

    Smirnov, Dmitri; ,

    2009-01-01

    In this report we focus on the performance of the D0 central fiber tracker and preshower detectors during the high luminosity p{bar p} collisions at {radical}s = 1.96 GeV delivered by the Tevatron collider at Fermilab (Run IIb). Both fiber tracker and preshower detectors utilize a similar readout system based on high quantum efficiency solid state photo-detectors capable of converting light into electrical signals. We also give a brief description of the D0 detector and the central track trigger, and conclude with a summary on the central tracker performance.

  19. Architecture of autonomous systems

    NASA Technical Reports Server (NTRS)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok; Larsen, Ronald L.

    1989-01-01

    Automation of Space Station functions and activities, particularly those involving robotic capabilities with interactive or supervisory human control, is a complex, multi-disciplinary systems design problem. A wide variety of applications using autonomous control can be found in the literature, but none of them seem to address the problem in general. All of them are designed with a specific application in mind. In this report, an abstract model is described which unifies the key concepts underlying the design of automated systems such as those studied by the aerospace contractors. The model has been kept as general as possible. The attempt is to capture all the key components of autonomous systems. With a little effort, it should be possible to map the functions of any specific autonomous system application to the model presented here.

  20. Architecture of autonomous systems

    NASA Technical Reports Server (NTRS)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok; Larsen, Ronald L.

    1986-01-01

    Automation of Space Station functions and activities, particularly those involving robotic capabilities with interactive or supervisory human control, is a complex, multi-disciplinary systems design problem. A wide variety of applications using autonomous control can be found in the literature, but none of them seem to address the problem in general. All of them are designed with a specific application in mind. In this report, an abstract model is described which unifies the key concepts underlying the design of automated systems such as those studied by the aerospace contractors. The model has been kept as general as possible. The attempt is to capture all the key components of autonomous systems. With a little effort, it should be possible to map the functions of any specific autonomous system application to the model presented here.

  1. Exercise and autonomic function.

    PubMed

    Goldsmith, R L; Bloomfield, D M; Rosenwinkel, E T

    2000-03-01

    The complex interplay between the dichotomous subdivisions of the autonomic nervous system establishes and maintains a delicately tuned homeostasis in spite of an ever-changing environment. Aerobic exercise training can increase activity of the parasympathetic nervous system and decrease sympathetic activity. Conversely, it is well-documented that cardiac disease is often characterized by attenuated parasympathetic activity and heightened sympathetic tone. A correlation between autonomic disequilibrium and disease has led to the hypothesis that exercise training, as a therapy that restores the autonomic nervous system towards normal function, may be associated with, and possibly responsible for, outcome improvements in various populations. This is merely one of the many benefits that is conferred by chronic exercise training and reviewed in this issue. PMID:10758814

  2. SDC conceptual design: Scintillating fiber outer tracker

    SciTech Connect

    Adams, D.; Baumbaugh, A.; Bird, F.; SDC Collaboration

    1992-01-22

    The authors propose an all-scintillating fiber detector for the purpose of outer tracking for the SDC. The objectives of this tracking system are to: (1) provide a first level trigger for {vert_bar}{eta}{vert_bar} < 2.3 with sharp p{sub T} threshold with the ability to resolve individual beam crossings; (2) provide pattern recognition capability and momentum resolution which complements and extends the capabilities of the inner silicon tracking system; (3) provide three dimensional linkage with outer detection systems including the shower maximum detector, muon detectors, and calorimetry; (4) provide robust tracking and track-triggering at the highest luminosities expected at the SSC. The many attractive features of a fiber tracker include good position resolution, low occupancy, low mass in the active volume, and excellent resistance to radiation damage. An additional important feature, especially at the SSC, is the intrinsically prompt response time of a scintillating fiber. This property is exploited in the construction of a level 1 trigger sensitive to individual beam crossings.

  3. ATLAS silicon microstrip tracker operation and performance

    NASA Astrophysics Data System (ADS)

    Barone, Gaetano

    2013-12-01

    The Semi-Conductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices of the Inner Detector of the ATLAS experiment at CERN LHC. The SCT is constructed of 4088 silicon detector modules for a total of 6.3 million channels. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The modules are mounted into two types of structures: one barrel (4 cylinders) and two end-cap systems (9 disks on each). The current results from the successful operation of the SCT Detector at the LHC and its status after three years of operation will be presented. The operation of the detector including an overview of the main issues encountered is reported. The main emphasis is given to the tracking performance of the SCT and the data quality during the >2 years of data taking of proton-proton collision data at 7 TeV (and short periods of heavy ion collisions). The SCT has been fully operational throughout all data taking periods, delivering high quality tracking data.

  4. Performance of the LHCb silicon tracker

    NASA Astrophysics Data System (ADS)

    Cowan, G. A.; the LHCb Silicon Tracker Group

    2013-01-01

    The LHCb detector has been optimised for the search for New Physics in CP violating observables and rare heavy-quark decays at the Large Hadron Collider (LHC). The detector is a single arm forward spectrometer with excellent tracking and particle identification capabilities. The LHCb silicon tracker is constructed from silicon micro-strip detectors with long readout strips. It consists of one four-layer tracking station upstream of the LHCb spectrometer magnet and three stations downstream of the magnet. The detectors have performed extremely well right from the start of LHC operation, permitting the experiment to collect data at instantaneous luminosities well exceeding the design value. In this presentation, an overview of the operational experience from the first two years of data taking at the LHC will be given, with special emphasis on problems encountered. Calibration procedures will be discussed as well as studies of the intrinsic detector efficiency and resolution. First measurements of the observed radiation damage will also be shown.

  5. Operation of the CMS silicon strip tracker

    NASA Astrophysics Data System (ADS)

    Yuri, Gotra; CMS Collaboration

    2011-10-01

    The CMS Silicon Strip Tracker (SST), comprising 9.6 million readout channels from 15148 modules covering an area of about 200 m², needs to be precisely calibrated in order to correctly interpret and reconstruct the events recorded from the detector, ensuring that the SST performance fully meets the physics research program of the CMS experiment. Calibration constants may be derived from promptly reconstructed events as well as from pedestal runs gathered just before the acquisition of physics runs. These calibration procedures were exercised in summer and winter 2009, when the CMS detector was commissioned using cosmic muons and proton-proton collisions at a center-of-mass energies of 900 GeV and 2.36 TeV. During these data taking periods the performance of the SST was carefully studied: the noise of the detector, the data integrity, the signal-to-noise ratio, the hit reconstruction efficiency, the calibration workflows have been all checked for stability and for different conditions, at the module level. The calibration procedures and the detector performance results from recent physics runs are described.

  6. Autonomous electrochromic assembly

    DOEpatents

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  7. Cardiovascular autonomic neuropathy

    PubMed Central

    McCarty, Niamh

    2016-01-01

    Cardiovascular autonomic neuropathy often goes unrecognized. We present a case of a 22-year-old man with multiple manifestations of this disease, including weakness, dizziness, fatigue, tachycardia, abnormal QTc, and orthostasis, which occurred 2 years after his type 1 diabetes diagnosis. He exhibited parasympathetic denervation with resting tachycardia and exercise intolerance but also had evidence of orthostatic hypotension, which suggests sympathetic denervation. He did not have complete cardiovascular autonomic reflex testing, which would have been helpful, but improved with aggressive diabetes treatment and the increase of beta-blockade. It is important to identify these patients to understand their signs and symptoms and consider appropriate therapies. PMID:27034552

  8. Cardiovascular autonomic neuropathy.

    PubMed

    McCarty, Niamh; Silverman, Barry

    2016-04-01

    Cardiovascular autonomic neuropathy often goes unrecognized. We present a case of a 22-year-old man with multiple manifestations of this disease, including weakness, dizziness, fatigue, tachycardia, abnormal QTc, and orthostasis, which occurred 2 years after his type 1 diabetes diagnosis. He exhibited parasympathetic denervation with resting tachycardia and exercise intolerance but also had evidence of orthostatic hypotension, which suggests sympathetic denervation. He did not have complete cardiovascular autonomic reflex testing, which would have been helpful, but improved with aggressive diabetes treatment and the increase of beta-blockade. It is important to identify these patients to understand their signs and symptoms and consider appropriate therapies. PMID:27034552

  9. The Autonomous Helicopter System

    NASA Astrophysics Data System (ADS)

    Gilmore, John F.

    1984-06-01

    This paper describes an autonomous airborne vehicle being developed at the Georgia Tech Engineering Experiment Station. The Autonomous Helicopter System (AHS) is a multi-mission system consisting of three distinct sections: vision, planning and control. Vision provides the local and global scene analysis which is symbolically represented and passed to planning as the initial route planning constraints. Planning generates a task dependent path for the vehicle to traverse which assures maximum mission system success as well as safety. Control validates the path and either executes the given route or feeds back to previous sections in order to resolve conflicts.

  10. D0 layer 0 innermost layer of silicon microstrip tracker

    SciTech Connect

    Hanagaki, K.; /Fermilab

    2006-01-01

    A new inner layer silicon strip detector has been built and will be installed in the existing silicon microstrip tracker in D0. They report on the motivation, design, and performance of this new detector.

  11. Performance studies of the CMS Strip Tracker before installation

    SciTech Connect

    Adam, W.; et al.

    2009-06-01

    In March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.

  12. PRIMUS: autonomous driving robot for military applications

    NASA Astrophysics Data System (ADS)

    Schwartz, Ingo

    2000-07-01

    This article describes the government experimental program PRIMUS (PRogram of Intelligent Mobile Unmanned Systems) and the achieved results of phase C demonstrated in summer 1999 on a military prooving ground. In this program there shall be shown the autonomous driving on an unmanned robot in open terrain. The most possible degree of autonomy shall be reached with today's technology to get a platform for different missions. The goal is to release the soldier from high dangerous tasks, to increase the performance and to come to a reduction of personnel and costs with unmanned systems. In phase C of the program two small tracked vehicles (Digitized Wiesel 2, airtransportable by CH53) are used. One as a robot vehicle the other as a command & control system. The Wiesel 2 is configured as a drive by wire-system and therefore well suited for the adaption of control computers. The autonomous detection and avoidance of obstacles in unknown, not cooperative environment is the main task. For navigation and orientation a sensor package is integrated. To detect obstacles the scene in the driving corridor of the robot is scanned 4 times per second by a 3D- Range image camera (LADAR). The measured 3D-range image is converted into a 2D-obstacle map and used as input for calculation of an obstacle free path. The combination of local navigation (obstacle avoidance) and global navigation leads to a collission free driving in open terrain to a predefined goal point with a velocity of up to 25km/h. A contour tracker with a TV-camera as sensor is also implemented which allows to follow contours (e.g. edge of a meadow) or to drive on paved or unpaved roads with a velocity up to 50km/h. In addition to these autonomous driving modes the operator in the command & control station can drive the robot by remote control. All the functions were successfully demonstrated in the summer 1999 on a military prooving ground. During a mission example the robot vehicle covered a distance of several

  13. HCPV trackers arrangement based on space coordinate transformations

    NASA Astrophysics Data System (ADS)

    Mi, Zhe; Chen, Nuofu; Liu, Hu; Bai, Yiming; Zhang, Xiulan; Chen, Jikun; Wang, Xiangwu

    2014-09-01

    A new pattern of space coordinate system based on sun-tracking surface has been introduced in this paper. The calculation of shadow area between HCPV trackers has been simplified within this kind of coordinate system. The spaces between rows and columns of HCPV arrays can be calculated accurately. Therefore, an appropriate layout of trackers arrangement for a HCPV power plant can be determined and designed by use of this method.

  14. EMC Diagnosis and Corrective Actions for Silicon Strip Tracker Detectors

    SciTech Connect

    Arteche, F.; Rivetta, C.; /SLAC

    2006-06-06

    The tracker sub-system is one of the five sub-detectors of the Compact Muon Solenoid (CMS) experiment under construction at CERN for the Large Hadron Collider (LHC) accelerator. The tracker subdetector is designed to reconstruct tracks of charged sub-atomic particles generated after collisions. The tracker system processes analogue signals from 10 million channels distributed across 14000 silicon micro-strip detectors. It is designed to process signals of a few nA and digitize them at 40 MHz. The overall sub-detector is embedded in a high particle radiation environment and a magnetic field of 4 Tesla. The evaluation of the electromagnetic immunity of the system is very important to optimize the performance of the tracker sub-detector and the whole CMS experiment. This paper presents the EMC diagnosis of the CMS silicon tracker sub-detector. Immunity tests were performed using the final prototype of the Silicon Tracker End-Caps (TEC) system to estimate the sensitivity of the system to conducted noise, evaluate the weakest areas of the system and take corrective actions before the integration of the overall detector. This paper shows the results of one of those tests, that is the measurement and analysis of the immunity to CM external conducted noise perturbations.

  15. Multi-expert tracking algorithm based on improved compressive tracker

    NASA Astrophysics Data System (ADS)

    Feng, Yachun; Zhang, Hong; Yuan, Ding

    2015-12-01

    Object tracking is a challenging task in computer vision. Most state-of-the-art methods maintain an object model and update the object model by using new examples obtained incoming frames in order to deal with the variation in the appearance. It will inevitably introduce the model drift problem into the object model updating frame-by-frame without any censorship mechanism. In this paper, we adopt a multi-expert tracking framework, which is able to correct the effect of bad updates after they happened such as the bad updates caused by the severe occlusion. Hence, the proposed framework exactly has the ability which a robust tracking method should process. The expert ensemble is constructed of a base tracker and its formal snapshot. The tracking result is produced by the current tracker that is selected by means of a simple loss function. We adopt an improved compressive tracker as the base tracker in our work and modify it to fit the multi-expert framework. The proposed multi-expert tracking algorithm significantly improves the robustness of the base tracker, especially in the scenes with frequent occlusions and illumination variations. Experiments on challenging video sequences with comparisons to several state-of-the-art trackers demonstrate the effectiveness of our method and our tracking algorithm can run at real-time.

  16. Star Light, Star Bright.

    ERIC Educational Resources Information Center

    Iadevaia, David G.

    1984-01-01

    Presents a technique for obtaining a rough measure of the brightness among different stars. Materials needed include a standard 35-mm camera, a plastic ruler, and a photo enlarger. Although a telescope can be used, it is not essential. (JN)

  17. Learning for autonomous navigation

    NASA Technical Reports Server (NTRS)

    Angelova, Anelia; Howard, Andrew; Matthies, Larry; Tang, Benyang; Turmon, Michael; Mjolsness, Eric

    2005-01-01

    Autonomous off-road navigation of robotic ground vehicles has important applications on Earth and in space exploration. Progress in this domain has been retarded by the limited lookahead range of 3-D sensors and by the difficulty of preprogramming systems to understand the traversability of the wide variety of terrain they can encounter.

  18. Developing Autonomous Learners.

    ERIC Educational Resources Information Center

    Mulcahy, Robert F.

    1991-01-01

    Defines the concept of autonomous learning. Presents the Strategies Program for Effective Learning/Thinking (SPELT), including its underlying assumptions, instructional model, teacher training procedures, research findings, and anticipated future development. Research results include implications for learning-disabled and gifted students. (KS)

  19. Autonomous data transmission apparatus

    DOEpatents

    Kotlyar, Oleg M.

    1997-01-01

    A autonomous borehole data transmission apparatus for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters.

  20. Performance of a day time star sensor for a stabilized balloon platform

    SciTech Connect

    Rossi, E.; DiCocco, G.; Donati, A.; Traci, A.; Quadrini, M.; Villa, G.; Ashton, T.; Court, A.J.

    1989-02-01

    A modified version of a CCD star tracker originally designed for use on the ROSAT X ray astronomy satellite, has been built for use on a three axis stabilized balloon platform. The first flight of this star sensor was planned for may 1988 from the NASA Balloon base at Palestine, Texas. The expected performance of this instrument is described along with the preflight results.

  1. HETDEX tracker control system design and implementation

    NASA Astrophysics Data System (ADS)

    Beno, Joseph H.; Hayes, Richard; Leck, Ron; Penney, Charles; Soukup, Ian

    2012-09-01

    To enable the Hobby-Eberly Telescope Dark Energy Experiment, The University of Texas at Austin Center for Electromechanics and McDonald Observatory developed a precision tracker and control system - an 18,000 kg robot to position a 3,100 kg payload within 10 microns of a desired dynamic track. Performance requirements to meet science needs and safety requirements that emerged from detailed Failure Modes and Effects Analysis resulted in a system of 13 precision controlled actuators and 100 additional analog and digital devices (primarily sensors and safety limit switches). Due to this complexity, demanding accuracy requirements, and stringent safety requirements, two independent control systems were developed. First, a versatile and easily configurable centralized control system that links with modeling and simulation tools during the hardware and software design process was deemed essential for normal operation including motion control. A second, parallel, control system, the Hardware Fault Controller (HFC) provides independent monitoring and fault control through a dedicated microcontroller to force a safe, controlled shutdown of the entire system in the event a fault is detected. Motion controls were developed in a Matlab-Simulink simulation environment, and coupled with dSPACE controller hardware. The dSPACE real-time operating system collects sensor information; motor commands are transmitted over a PROFIBUS network to servo amplifiers and drive motor status is received over the same network. To interface the dSPACE controller directly to absolute Heidenhain sensors with EnDat 2.2 protocol, a custom communication board was developed. This paper covers details of operational control software, the HFC, algorithms, tuning, debugging, testing, and lessons learned.

  2. Software Architecture for Autonomous Spacecraft

    NASA Technical Reports Server (NTRS)

    Shih, Jimmy S.

    1997-01-01

    The thesis objective is to design an autonomous spacecraft architecture to perform both deliberative and reactive behaviors. The Autonomous Small Planet In-Situ Reaction to Events (ASPIRE) project uses the architecture to integrate several autonomous technologies for a comet orbiter mission.

  3. The STAR TPC front end electronics

    SciTech Connect

    Klein, S.R.; Barale, P.; Beuville, E.

    1995-10-01

    The Solenoidal Tracker at RHIC (STAR) uses a large time projection chamber. Each of the 136,600 pads is instrumented with a waveform digitizer, implemented in custom low noise preamplifier/shaper and switched capacitor array/ADCs ICs. The system is highly integrated with all analog functions mounted on small cards that plug into the TPC. Detector mounted readout boards multiplex data from 1152 channels onto a 1.5 Gbit/sec fiber optic link to the data acquisition system.

  4. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Petrik, Edward J.; Roth, Mary Ellen; Truong, Long Van; Quinn, Todd; Krawczonek, Walter M.

    1990-01-01

    The Autonomous Power Expert (APEX) system was designed to monitor and diagnose fault conditions that occur within the Space Station Freedom Electrical Power System (SSF/EPS) Testbed. APEX is designed to interface with SSF/EPS testbed power management controllers to provide enhanced autonomous operation and control capability. The APEX architecture consists of three components: (1) a rule-based expert system, (2) a testbed data acquisition interface, and (3) a power scheduler interface. Fault detection, fault isolation, justification of probable causes, recommended actions, and incipient fault analysis are the main functions of the expert system component. The data acquisition component requests and receives pertinent parametric values from the EPS testbed and asserts the values into a knowledge base. Power load profile information is obtained from a remote scheduler through the power scheduler interface component. The current APEX design and development work is discussed. Operation and use of APEX by way of the user interface screens is also covered.

  5. Mobile Autonomous Humanoid Assistant

    NASA Technical Reports Server (NTRS)

    Diftler, M. A.; Ambrose, R. O.; Tyree, K. S.; Goza, S. M.; Huber, E. L.

    2004-01-01

    A mobile autonomous humanoid robot is assisting human co-workers at the Johnson Space Center with tool handling tasks. This robot combines the upper body of the National Aeronautics and Space Administration (NASA)/Defense Advanced Research Projects Agency (DARPA) Robonaut system with a Segway(TradeMark) Robotic Mobility Platform yielding a dexterous, maneuverable humanoid perfect for aiding human co-workers in a range of environments. This system uses stereo vision to locate human team mates and tools and a navigation system that uses laser range and vision data to follow humans while avoiding obstacles. Tactile sensors provide information to grasping algorithms for efficient tool exchanges. The autonomous architecture utilizes these pre-programmed skills to form human assistant behaviors. The initial behavior demonstrates a robust capability to assist a human by acquiring a tool from a remotely located individual and then following the human in a cluttered environment with the tool for future use.

  6. Human factor requirements of helmet trackers for HMDs

    NASA Astrophysics Data System (ADS)

    Martinsen, Gary L.; Havig, Paul R.; Post, David L.; Reis, George A.; Simpson, Matthew A.

    2003-09-01

    A helmet tracker is a critical element in the path that delivers targeting and other sensor data to the user of a helmet-mounted display (HMD) in a military aircraft. The original purpose of an HMD was to serve as a helmet-mounted sight and provide a means to fully utilize the capabilities of off-boresight munitions. Recently, the role of the HMD has evolved from being strictly a targeting tool to providing detailed flight path and situation awareness information. These changes, however, have placed even greater value on the visual information that is transferred through the helmet tracker to the HMD. Specifically, the timeliness and accuracy of the information, which is of critical importance when the HMD is used as a targeting aid, is of even greater importance when the HMD is used to display flight reference information. This is especially relevant since it has been proposed to build new military aircraft without a physical head-up display (HUD) and display HUD information virtually with an HMD. In this paper, we review the current state of helmet tracker technology with respect to use in military aviation. We also identify the parameters of helmet trackers that offer the greatest risk when using an HMD to provide information beyond targeting data to the user. Finally, we discuss the human factors limitations of helmet tracker systems for delivering both targeting and flight reference information to a military pilot.

  7. Construction and commissioning of the SuperNEMO detector tracker

    NASA Astrophysics Data System (ADS)

    Cascella, Michele

    2016-07-01

    The SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory; the detector design allows complete topological reconstruction of the decay event enabling excellent levels of background rejection and, in the event of a discovery, the ability to determine the nature of the lepton number violating process. In order to demonstrate the feasibility of the full experiment, we are building a Demonstrator Module containing 7 kg of 82Se, with an expected sensitivity of |mββ | < 0.2 - 0.4 eV after 2.5 yr. The demonstrator tracker is currently being assembled in the UK; the main challenge in the tracker design is the high radiopurity required to limit the background. For this reason the cell wiring is automated and every step of the tracker assembly happens in a clean environment. All components are carefully screened for radiopurity and each section of the tracker, once assembled, is sealed and checked for Radon emanation. We present the detector design, the current status of the construction and present the first results from the surface commissioning of one section of the Demonstrator Module tracker.

  8. Nature's Autonomous Oscillators

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  9. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling and dynamic replanning.

  10. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling an dynamic replanning.

  11. Trigeminal autonomic cephalalgias.

    PubMed

    Eller, M; Goadsby, P J

    2016-01-01

    The trigeminal autonomic cephalalgias (TACs) are a group of primary headache disorders characterised by lateralized symptoms: prominent headache and ipsilateral cranial autonomic features, such as conjunctival injection, lacrimation and rhinorrhea. The TACs are: cluster headache (CH), paroxysmal hemicrania (PH), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)/short-lasting neuralgiform headache attacks with cranial autonomic features (SUNA) and hemicrania continua (HC). Their diagnostic criteria are outlined in the International Classification of Headache Disorders, third edition-beta (ICHD-IIIb). These conditions are distinguished by their attack duration and frequency, as well as response to treatment. HC is continuous and by definition responsive to indomethacin. The main differential when considering this headache is chronic migraine. Other TACs are remarkable for their short duration and must be distinguished from other short-lasting painful conditions, such as trigeminal neuralgia and primary stabbing headache. Cluster headache is characterised by exquisitely painful attacks that occur in discrete episodes lasting 15-180 min a few times a day. In comparison, PH occurs more frequently and is of shorter duration, and like HC is responsive to indomethacin. SUNCT/SUNA is the shortest duration and highest frequency TAC; attacks can occur over a hundred times every day. PMID:24888770

  12. Strange stars

    NASA Technical Reports Server (NTRS)

    Alcock, Charles; Farhi, Edward; Olinto, Angela

    1986-01-01

    Strange matter, a form of quark matter that is postulated to be absolute stable, may be the true ground stage of the hadrons. If this hypothesis is correct, neutron stars may convert to 'strange stars'. The mass-radius relation for strange stars is very different from that of neutron stars; there is no minimum mass, and for mass of 1 solar mass or less, mass is proportional to the cube of the radius. For masses between 1 solar mass and 2 solar masses, the radii of strange stars are about 10 km, as for neutron stars. Strange stars may have an exposed quark surface, which is capable of radiating at rates greatly exceeding the Eddington limit, but has a low emissivity for X-ray photons. The stars may have a thin crust with the same composition as the preneutron drip outer layer of a conventional neutron star crust. Strange stars cool efficiently via neutrino emission.

  13. Stars and Star Myths.

    ERIC Educational Resources Information Center

    Eason, Oliver

    Myths and tales from around the world about constellations and facts about stars in the constellations are presented. Most of the stories are from Greek and Roman mythology; however, a few Chinese, Japanese, Polynesian, Arabian, Jewish, and American Indian tales are also included. Following an introduction, myths are presented for the following 32…

  14. Be Stars

    NASA Astrophysics Data System (ADS)

    Peters, G.; Murdin, P.

    2000-11-01

    A Be star (pronounced `bee-ee' star) is a non-supergiant B-type star whose spectrum displays or has displayed one or more Balmer lines in emission and Be is the notation for the spectral classification of such a star (see also CLASSIFICATION OF STELLAR SPECTRA). `Classical' Be stars are believed to have acquired the circumstellar (CS) material that produces the Balmer emission through ejection of...

  15. Development of a Robust star identification technique for use in attitude determination of the ACE spacecraft

    NASA Technical Reports Server (NTRS)

    Woodard, Mark; Rohrbaugh, Dave

    1995-01-01

    The Advanced Composition Explorer (ACE) spacecraft is designed to fly in a spin-stabilized attitude. The spacecraft will carry two attitude sensors - a digital fine Sun sensor and a charge coupled device (CCD) star tracker - to allow ground-based determination of the spacecraft attitude and spin rate. Part of the processing that must be performed on the CCD star tracker data is the star identification. Star data received from the spacecraft must be matched with star information in the SKYMAP catalog to determine exactly which stars the sensor is tracking. This information, along with the Sun vector measured by the Sun sensor, is used to determine the spacecraft attitude. Several existing star identification (star ID) systems were examined to determine whether they could be modified for use on the ACE mission. Star ID systems which exist for three-axis stabilized spacecraft tend to be complex in nature and many require fairly good knowledge of the spacecraft attitude, making their use for ACE excessive. Star ID systems used for spinners carrying traditional slit star sensors would have to be modified to model the CCD star tracker. The ACE star ID algorithm must also be robust, in that it will be able to correctly identify stars even though the attitude is not known to a high degree of accuracy, and must be very efficient to allow real-time star identification. The paper presents the star ID algorithm that was developed for ACE. Results from prototype testing are also presented to demonstrate the efficiency, accuracy, and robustness of the algorithm.

  16. The Reconstruction Software for the Muon Ionization Cooling Experiment Trackers

    SciTech Connect

    Dobbs, A.; Long, K.; Santos, E.; Adey, D.; Hanlet, P.; Heidt, C.

    2014-01-01

    The international Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate the principle of muon ionization cooling, for application to a future Neutrino Factory or Muon Collider. In order to measure the change in emittance, MICE is equipped with a pair of high precision scintillating fibre trackers. The trackers are required to measure a 10% change in emittance to 1% accuracy (giving an overall precision of 0.1%). This paper describes the tracker reconstruction software, as a part of the overall MICE software framework, MAUS. Channel clustering is described, proceeding to the formation of space-points, which are then associated with particle tracks using pattern recognition algorithms. Finally a full custom Kalman track fit is performed, to account for energy loss and multiple scattering. Exemplar results are shown for Monte Carlo data.

  17. Geographos asteroid flyby and autonomous navigation study

    SciTech Connect

    Ng, L.C.; Pines, D.J.; Patz, B.J.; Perron, D.C.

    1993-02-22

    Deep Space Program Science Experiment (DSPSE), also known as Clementine, is a collection of science experiments conducted in near-earth with the goal of demonstrating Strategic Defense Initiative Office (SDIO) developed technologies. The 785 lb (fully fueled) spacecraft will be launched into low Earth orbit in February 1994 together with a Star 37 solid kick motor and interstage. After orbit circulation using Clementine`s 110 lb Delta-V thruster, the Star 37 will execute a trans-lunar injection burn that will send the spacecraft toward lunar obit. The 110-lb will then be used in a sequence of burns to insert Clementine into a trimmed, polar orbit around the moon. After a two month moon mapping mission, Clementine will execute burns to leave lunar orbit, sling-shot around Earth, and flyby the moon on a 9.4 million km journey toward the asteroid Geographos. After about three months in transit, Clementine will attempt a flyby with a closest point of approach of 100 km from the asteroid on August 31, 1994. During its approach to Geographos, Clementine will be tracked by the Deep Space Network (DSN) and receive guidance updates. The last update and correction burn will occur about one day out of the flyby. Multiple experiments will be performed at key events during the mission that utilize Clementine`s SDIO-derived resources, including its Star Trackers, UV/Vis camera, infrared sensors (NWIR and LWIR), and high resolution laser radar (HIRes/LIDAR). In addition to the evaluation of SDIO algorithms and sensors, high resolution imagery will be obtained while the spacecraft is in Earth orbit, lunar obit and during the Geographos flyby. This paper describes the results of a study on the precision guidance, navigation, and intercept strategy for the flyby mission.

  18. Laser tracker TSPI uncertainty quantification via centrifuge trajectory

    NASA Astrophysics Data System (ADS)

    Romero, Edward; Paez, Thomas; Brown, Timothy; Miller, Timothy

    2009-08-01

    Sandia National Laboratories currently utilizes two laser tracking systems to provide time-space-position-information (TSPI) and high speed digital imaging of test units under flight. These laser trackers have been in operation for decades under the premise of theoretical accuracies based on system design and operator estimates. Advances in optical imaging and atmospheric tracking technology have enabled opportunities to provide more precise six degree of freedom measurements from these trackers. Applying these technologies to the laser trackers requires quantified understanding of their current errors and uncertainty. It was well understood that an assortment of variables contributed to laser tracker uncertainty but the magnitude of these contributions was not quantified and documented. A series of experiments was performed at Sandia National Laboratories large centrifuge complex to quantify TSPI uncertainties of Sandia National Laboratories laser tracker III. The centrifuge was used to provide repeatable and economical test unit trajectories of a test-unit to use for TSPI comparison and uncertainty analysis. On a centrifuge, testunits undergo a known trajectory continuously with a known angular velocity. Each revolution may represent an independent test, which may be repeated many times over for magnitudes of data practical for statistical analysis. Previously these tests were performed at Sandia's rocket sled track facility but were found to be costly with challenges in the measurement ground truth TSPI. The centrifuge along with on-board measurement equipment was used to provide known ground truth position of test units. This paper discusses the experimental design and techniques used to arrive at measures of laser tracker error and uncertainty.

  19. The STAR experiment at RHIC

    SciTech Connect

    Marx, J.N.; STAR Collaboration

    1994-01-01

    STAR (Solenoidal Tracker at RHIC) will be one of two large, sophisticated experiments ready to take data when the Relativistic Heavy Ion Collider (RHIC) comes on-line in 1999. The design of STAR, its construction and commissioning and the physics program using the detector are the responsibility of a collaboration of over 250 members from 30 institutions, world-wide. The overall approach of the STAR Collaboration to the physics challenge of studying collisions of highly relativistic nuclei is to focus on measurements of the properties of the many hadrons produced in the collisions. The STAR detector is optimized to detect and identify hadrons over a large solid angle so that individual events can be characterized, in detail, based on their hadronic content. The broad capabilities of the STAR detector will permit an examination of a wide variety of proposed signatures for the Quark Gluon Plasma (QGP), using the sample of events which, on an event-by-event basis, appear to come from collisions resulting in a large energy density over a nuclear volume. In order to achieve this goal, the STAR experiment is based on a solenoid geometry with tracking detectors using the time projection chamber approach and covering a large range of pseudo-rapidity so that individual tracks can be seen within the very high track density expected in central collisions at RHIC. STAR also uses particle identification by the dE/dx technique and by time-of-flight. Electromagnetic energy is detected in a large, solid-angle calorimeter. The construction of STAR, which will be located in the Wide Angle Hall at the 6 o`clock position at RHIC, formally began in early 1993.

  20. Silicon vertex tracker: a fast precise tracking trigger for CDF

    NASA Astrophysics Data System (ADS)

    Ashmanskas, W.; Bardi, A.; Bari, M.; Belforte, S.; Berryhill, J.; Bogdan, M.; Cerri, A.; Clark, A. G.; Chlanchidze, G.; Condorelli, R.; Culbertson, R.; Dell'Orso, M.; Donati, S.; Frisch, H. J.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Leger, A.; Meschi, E.; Morsani, F.; Nakaya, T.; Punzi, G.; Ristori, L.; Sanders, H.; Semenov, A.; Signorelli, G.; Shochet, M.; Speer, T.; Spinella, F.; Wilson, P.; Wu, Xin; Zanetti, A. M.

    2000-06-01

    The Silicon Vertex Tracker (SVT), currently being built for the CDF II experiment, is a hardware device that reconstructs 2-D tracks online using measurements from the Silicon Vertex Detector (SVXII) and the Central Outer Tracker (COT). The precise measurement of the impact parameter of the SVT tracks will allow, for the first time in a hadron collider environment, to trigger on events containing B hadrons that are very important for many studies, such as CP violation in the b sector and searching for new heavy particles decaying to b b¯ . In this report we describe the overall architecture, algorithms and the hardware implementation of the SVT.

  1. Results from the E835 cylindrical scintillating-fiber tracker

    SciTech Connect

    Ambrogiani, M.; Baldini, W.; Bettoni, D.; Calabrese, R.; Luppi, E.; Mussa, R.; Stancari, G. |

    1998-11-01

    A cylindrical 860-channel scintillating-fiber tracker for the measurement of the polar coordinate {theta} has been built for experiment 835 at Fermi National Accelerator Laboratory; it was used during the data-taking period, from October 1996 through September 1997. The high granularity, flexibility and fast response of the scintillating fibers are combined with the high quantum efficiency of the Visible-Light Photon Counters. From this combination, a new kind of detector arises, capable of high-resolution tracking, fast first-level kinematical triggering and single/double-track discrimination. Results of the tracker performance are presented. {copyright} {ital 1998 American Institute of Physics.}

  2. Construction of the tracker for the SuperNEMO experiment

    NASA Astrophysics Data System (ADS)

    Guzowski, P.

    2015-04-01

    The SuperNEMO experiment will search for neutrinoless double β decay with a sensitivity two orders of magnitude greater than its predecessor NEMO-3, achieved through better energy resolution and unprecedented background levels. A Demonstrator module of the detector is currently under construction, due to begin data taking in 2015. A vital component of the detector is the tracker, a wire chamber made from 2,034 cells operating in Geiger mode. This is important for triggering, background discrimination, and measurement of the kinematic properties of the decay. The tracker production procedure and status is presented.

  3. Simulation of the GEM silicon central tracker using GEANT

    SciTech Connect

    Brooks, M.L.; Kinnison, W.W.

    1994-01-01

    The silicon central tracker of the GEM detector has been simulated using the high energy physics simulations code GEANT. This paper will describe the level of detail of the geometry of the tracker that is in the code, including the silicon detectors themselves as well as all non-sensitive volumes such as support structures; the digitization, or detector response to particles, of the silicon detectors; the coordinate reconstruction from the digitizations, and some of the results of the simulations regarding the detector performance.

  4. Characterization of the Ecosole HCPV tracker and single module inverter

    NASA Astrophysics Data System (ADS)

    Carpanelli, Maurizio; Borelli, Gianni; Verdilio, Daniele; De Nardis, Davide; Migali, Fabrizio; Cancro, Carmine; Graditi, Giorgio

    2015-09-01

    BECAR, the Beghelli group's R&D company, is leading ECOSOLE (Elevated COncentration SOlar Energy), one of the largest European Demonstration projects in solar photovoltaic. ECOSOLE, started in 2012, is focused on the study, design, and realization of new HCPV generator made of high efficiency PV modules equipped with SoG (Silicone on Glass) fresnel lenses and III-V solar cells, and a low cost matched solar tracker with distributed inverters approach. The project also regards the study and demonstration of new high throughput methods for the industrial large scale productions, at very low manufacturing costs. This work reports the description of the characterization of the tracker and single module.

  5. Environmental Tests of the Flight GLAST LAT Tracker Towers

    SciTech Connect

    Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; Angelis, A.De; Drell, P.; Favuzzi, C.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Goodman, J.; Himel, T.

    2008-03-12

    The Gamma-ray Large Area Space telescope (GLAST) is a gamma-ray satellite scheduled for launch in 2008. Before the assembly of the Tracker subsystem of the Large Area Telescope (LAT) science instrument of GLAST, every component (tray) and module (tower) has been subjected to extensive ground testing required to ensure successful launch and on-orbit operation. This paper describes the sequence and results of the environmental tests performed on an engineering model and all the flight hardware of the GLAST LAT Tracker. Environmental tests include vibration testing, thermal cycles and thermal-vacuum cycles of every tray and tower as well as the verification of their electrical performance.

  6. Autonomous Space Shuttle

    NASA Technical Reports Server (NTRS)

    Siders, Jeffrey A.; Smith, Robert H.

    2004-01-01

    The continued assembly and operation of the International Space Station (ISS) is the cornerstone within NASA's overall Strategic P an. As indicated in NASA's Integrated Space Transportation Plan (ISTP), the International Space Station requires Shuttle to fly through at least the middle of the next decade to complete assembly of the Station, provide crew transport, and to provide heavy lift up and down mass capability. The ISTP reflects a tight coupling among the Station, Shuttle, and OSP programs to support our Nation's space goal . While the Shuttle is a critical component of this ISTP, there is a new emphasis for the need to achieve greater efficiency and safety in transporting crews to and from the Space Station. This need is being addressed through the Orbital Space Plane (OSP) Program. However, the OSP is being designed to "complement" the Shuttle as the primary means for crew transfer, and will not replace all the Shuttle's capabilities. The unique heavy lift capabilities of the Space Shuttle is essential for both ISS, as well as other potential missions extending beyond low Earth orbit. One concept under discussion to better fulfill this role of a heavy lift carrier, is the transformation of the Shuttle to an "un-piloted" autonomous system. This concept would eliminate the loss of crew risk, while providing a substantial increase in payload to orbit capability. Using the guidelines reflected in the NASA ISTP, the autonomous Shuttle a simplified concept of operations can be described as; "a re-supply of cargo to the ISS through the use of an un-piloted Shuttle vehicle from launch through landing". Although this is the primary mission profile, the other major consideration in developing an autonomous Shuttle is maintaining a crew transportation capability to ISS as an assured human access to space capability.

  7. Collaborating with Autonomous Agents

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Cross, Charles D.; Fan, Henry; Hempley, Lucas E.; Motter, Mark A.; Neilan, James H.; Qualls, Garry D.; Rothhaar, Paul M.; Tran, Loc D.; Allen, B. Danette

    2015-01-01

    With the anticipated increase of small unmanned aircraft systems (sUAS) entering into the National Airspace System, it is highly likely that vehicle operators will be teaming with fleets of small autonomous vehicles. The small vehicles may consist of sUAS, which are 55 pounds or less that typically will y at altitudes 400 feet and below, and small ground vehicles typically operating in buildings or defined small campuses. Typically, the vehicle operators are not concerned with manual control of the vehicle; instead they are concerned with the overall mission. In order for this vision of high-level mission operators working with fleets of vehicles to come to fruition, many human factors related challenges must be investigated and solved. First, the interface between the human operator and the autonomous agent must be at a level that the operator needs and the agents can understand. This paper details the natural language human factors e orts that NASA Langley's Autonomy Incubator is focusing on. In particular these e orts focus on allowing the operator to interact with the system using speech and gestures rather than a mouse and keyboard. With this ability of the system to understand both speech and gestures, operators not familiar with the vehicle dynamics will be able to easily plan, initiate, and change missions using a language familiar to them rather than having to learn and converse in the vehicle's language. This will foster better teaming between the operator and the autonomous agent which will help lower workload, increase situation awareness, and improve performance of the system as a whole.

  8. Autonomous Phase Retrieval Calibration

    NASA Technical Reports Server (NTRS)

    Estlin, Tara A.; Chien, Steve A.; Castano, Rebecca; Gaines, Daniel M.; Doubleday, Joshua R.; Schoolcraft, Josua B.; Oyake, Amalaye; Vaughs, Ashton G.; Torgerson, Jordan L.

    2011-01-01

    The Palomar Adaptive Optics System actively corrects for changing aberrations in light due to atmospheric turbulence. However, the underlying internal static error is unknown and uncorrected by this process. The dedicated wavefront sensor device necessarily lies along a different path than the science camera, and, therefore, doesn't measure the true errors along the path leading to the final detected imagery. This is a standard problem in adaptive optics (AO) called "non-common path error." The Autonomous Phase Retrieval Calibration (APRC) software suite performs automated sensing and correction iterations to calibrate the Palomar AO system to levels that were previously unreachable.

  9. Autonomous mobile robot teams

    NASA Technical Reports Server (NTRS)

    Agah, Arvin; Bekey, George A.

    1994-01-01

    This paper describes autonomous mobile robot teams performing tasks in unstructured environments. The behavior and the intelligence of the group is distributed, and the system does not include a central command base or leader. The novel concept of the Tropism-Based Cognitive Architecture is introduced, which is used by the robots in order to produce behavior transforming their sensory information to proper action. The results of a number of simulation experiments are presented. These experiments include worlds where the robot teams must locate, decompose, and gather objects, and defend themselves against hostile predators, while navigating around stationary and mobile obstacles.

  10. Toward autonomous spacecraft

    NASA Technical Reports Server (NTRS)

    Fogel, L. J.; Calabrese, P. G.; Walsh, M. J.; Owens, A. J.

    1982-01-01

    Ways in which autonomous behavior of spacecraft can be extended to treat situations wherein a closed loop control by a human may not be appropriate or even possible are explored. Predictive models that minimize mean least squared error and arbitrary cost functions are discussed. A methodology for extracting cyclic components for an arbitrary environment with respect to usual and arbitrary criteria is developed. An approach to prediction and control based on evolutionary programming is outlined. A computer program capable of predicting time series is presented. A design of a control system for a robotic dense with partially unknown physical properties is presented.

  11. Autonomous interplanetary constellation design

    NASA Astrophysics Data System (ADS)

    Chow, Cornelius Channing, II

    According to NASA's integrated space technology roadmaps, space-based infrastructures are envisioned as necessary ingredients to a sustained effort in continuing space exploration. Whether it be for extra-terrestrial habitats, roving/cargo vehicles, or space tourism, autonomous space networks will provide a vital communications lifeline for both future robotic and human missions alike. Projecting that the Moon will be a bustling hub of activity within a few decades, a near-term opportunity for in-situ infrastructure development is within reach. This dissertation addresses the anticipated need for in-space infrastructure by investigating a general design methodology for autonomous interplanetary constellations; to illustrate the theory, this manuscript presents results from an application to the Earth-Moon neighborhood. The constellation design methodology is formulated as an optimization problem, involving a trajectory design step followed by a spacecraft placement sequence. Modeling the dynamics as a restricted 3-body problem, the investigated design space consists of families of periodic orbits which play host to the constellations, punctuated by arrangements of spacecraft autonomously guided by a navigation strategy called LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation). Instead of more traditional exhaustive search methods, a numerical continuation approach is implemented to map the admissible configuration space. In particular, Keller's pseudo-arclength technique is used to follow folding/bifurcating solution manifolds, which are otherwise inaccessible with other parameter continuation schemes. A succinct characterization of the underlying structure of the local, as well as global, extrema is thus achievable with little a priori intuition of the solution space. Furthermore, the proposed design methodology offers benefits in computation speed plus the ability to handle mildly stochastic systems. An application of the constellation design

  12. Pulsating Stars

    NASA Astrophysics Data System (ADS)

    Catelan, M.; Smith, H. A.

    2015-03-01

    This book surveys our understanding of stars which change in brightness because they pulsate. Pulsating variable stars are keys to distance scales inside and beyond the Milky Way galaxy. They test our understanding not only of stellar pulsation theory but also of stellar structure and evolution theory. Moreover, pulsating stars are important probes of the formation and evolution of our own and neighboring galaxies. Our understanding of pulsating stars has greatly increased in recent years as large-scale surveys of pulsating stars in the Milky Way and other Local Group galaxies have provided a wealth of new observations and as space-based instruments have studied particular pulsating stars in unprecedented detail.

  13. Autonomous satellite navigation using starlight refraction angle measurements

    NASA Astrophysics Data System (ADS)

    Ning, Xiaolin; Wang, Longhua; Bai, Xinbei; Fang, Jiancheng

    2013-05-01

    An on-board autonomous navigation capability is required to reduce the operation costs and enhance the navigation performance of future satellites. Autonomous navigation by stellar refraction is a type of autonomous celestial navigation method that uses high-accuracy star sensors instead of Earth sensors to provide information regarding Earth's horizon. In previous studies, the refraction apparent height has typically been used for such navigation. However, the apparent height cannot be measured directly by a star sensor and can only be calculated by the refraction angle and an atmospheric refraction model. Therefore, additional errors are introduced by the uncertainty and nonlinearity of atmospheric refraction models, which result in reduced navigation accuracy and reliability. A new navigation method based on the direct measurement of the refraction angle is proposed to solve this problem. Techniques for the determination of the refraction angle are introduced, and a measurement model for the refraction angle is established. The method is tested and validated by simulations. When the starlight refraction height ranges from 20 to 50 km, a positioning accuracy of better than 100 m can be achieved for a low-Earth-orbit (LEO) satellite using the refraction angle, while the positioning accuracy of the traditional method using the apparent height is worse than 500 m under the same conditions. Furthermore, an analysis of the factors that affect navigation accuracy, including the measurement accuracy of the refraction angle, the number of visible refracted stars per orbit and the installation azimuth of star sensor, is presented. This method is highly recommended for small satellites in particular, as no additional hardware besides two star sensors is required.

  14. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    ERIC Educational Resources Information Center

    Wee, Loo Kang; Chew, Charles; Goh, Giam Hwee; Tan, Samuel; Lee, Tat Leong

    2012-01-01

    This article reports on the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When a computer model building learning process is supported and driven by video analysis data, this free Open Source Physics tool can provide opportunities for students to engage in active enquiry-based…

  15. Upgrading the ATLAS barrel tracker for the super-LHC

    NASA Astrophysics Data System (ADS)

    Bates, Richard L.; ATLAS ID Collaboration

    2009-08-01

    It has been proposed to increase the luminosity of the large hadron collider (LHC) at CERN by an order of magnitude, with the upgraded machine dubbed super-LHC. The ATLAS experiment will require a new tracker for this high-luminosity operation due to radiation damage and event density. In order to cope with the order of magnitude increase in pile-up backgrounds at the higher luminosity, an all-silicon tracker is being designed. The new strip detector will use significantly shorter strips than the current silicon tracker in order to minimize the occupancy. As the increased luminosity will mean a corresponding increase in radiation dose, a new generation of extremely radiation-hard silicon detectors is required. An R&D program is underway to develop silicon sensors with sufficient radiation hardness. New front-end electronics and readout systems are being designed to cope with the higher data rates. The challenges facing the sensors and the cooling and mechanical support will be discussed. A possible tracker layout will be described.

  16. Highly integrated near-to-eye display and gaze tracker

    NASA Astrophysics Data System (ADS)

    Järvenpää, Toni; Äyräs, Pekka

    2010-05-01

    We have developed a Near-to-Eye Display (NED) technology based on diffractive optics. Thin and highly transparent plastic light guides enable a light-weight and ergonomic see-through NED design. We have previously reported of a compact NED with an integrated gaze tracker. Eye gaze tracker can detect the user's focus point in the displayed image. We have now made advances to further increase the level of integration as well as to enable the optical see-through. Originally, three separate light guides were used: two for the display (red, green/blue) and one for infrared light of the gaze tracker. To reduce weight and the system complexity, a shared light guide is now used for transmitting red (~630 nm, display) and infrared (~850 nm, gaze tracker) wavelengths. In addition, shared output gratings are used for outcoupling the light. Light guide plates have been characterized by measuring their modulation transfer functions. Measurements show that the deterioration of the NED's resolution, caused by the light guides, is reduced with improved manufacturing techniques. Also, it has been verified that the additional gratings for infrared (light in-coupling and expansion areas) do not have a notable effect on the display resolution.

  17. The CDF II eXtremely fast tracker upgrade

    SciTech Connect

    Abulencia, A.; Azzurri, P.; Cochran, E.; Dittmann, J.; Donati, S.; Efron, J.; Erbacher, R.; Errede, D.; Fedorko, I.; Flanagan, G.; Forrest, R.; /Illinois U., Urbana /INFN, Pisa /Pisa U. /Ohio State U. /Baylor U. /UC, Davis /Athens Natl. Capodistrian U. /Purdue U. /Fermilab

    2006-09-01

    The CDF II Extremely Fast Tracker is the trigger track processor which reconstructs charged particle tracks in the transverse plane of the CDF II central outer tracking chamber. The system is now being upgraded to perform a three dimensional track reconstruction. A review of the upgrade is presented here.

  18. CMS tracker performance and readiness for LHC Run II

    NASA Astrophysics Data System (ADS)

    Viliani, L.

    2016-07-01

    The CMS tracker performance during LHC Run I is reviewed. The latest results of both pixel and strip detectors following the first LHC Long Shutdown (LS1) are then presented. Results from detector calibration and commissioning, together with a description of operations and repairs done during LS1, will be shown.

  19. Using "Tracker" to Prove the Simple Harmonic Motion Equation

    ERIC Educational Resources Information Center

    Kinchin, John

    2016-01-01

    Simple harmonic motion (SHM) is a common topic for many students to study. Using the free, though versatile, motion tracking software; "Tracker", we can extend the students experience and show that the general equation for SHM does lead to the correct period of a simple pendulum.

  20. Using Tracker to prove the simple harmonic motion equation

    NASA Astrophysics Data System (ADS)

    Kinchin, John

    2016-09-01

    Simple harmonic motion (SHM) is a common topic for many students to study. Using the free, though versatile, motion tracking software; Tracker, we can extend the students experience and show that the general equation for SHM does lead to the correct period of a simple pendulum.

  1. Evaluating YieldTracker forecast for maize in western Kansas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We seek to predict in-season land productivity to guide irrigation management decisions designed to optimize water utilization in the Ogallala Aquifer region. YieldTracker is a mathematical model that simulates growth and yield of graminoid crops using weather and leaf area index (LAI) as inputs, wh...

  2. The barrel modules of the ATLAS semiconductor tracker

    NASA Astrophysics Data System (ADS)

    Abdesselam, A.; Akimoto, T.; Allport, P. P.; Alonso, J.; Anderson, B.; Andricek, L.; Anghinolfi, F.; Apsimon, R. J.; Barbier, G.; Barr, A. J.; Batchelor, L. E.; Bates, R. L.; Batley, J. R.; Beck, G. A.; Bell, P. J.; Belymam, A.; Bernabeu, J.; Bethke, S.; Bizzell, J. P.; Bohm, J.; Brenner, R.; Brodbeck, T. J.; Broklova, Z.; Broz, J.; Bruckman De Renstrom, P.; Buttar, C. M.; Butterworth, J. M.; Carpentieri, C.; Carter, A. A.; Carter, J. R.; Charlton, D. G.; Cheplakov, A.; Chesi, E.; Chilingarov, A.; Chouridou, S.; Chu, M. L.; Cindro, V.; Ciocio, A.; Civera, J. V.; Clark, A.; Coe, P.; Colijn, A.-P.; Cornelissen, T.; Cosgrove, D. P.; Costa, M. J.; Dabrowski, W.; Dalmau, J.; Danielsen, K. M.; Dawson, I.; Demirkoz, B.; Dervan, P.; Dolezal, Z.; Donega, M.; D'Onofrio, M.; Dorholt, O.; Dowell, J. D.; Drasal, Z.; Duerdoth, I. P.; Dwuznik, M.; Eckert, S.; Ekelof, T.; Eklund, L.; Escobar, C.; Fadeyev, V.; Feld, L.; Ferrari, P.; Ferrere, D.; Fiorini, L.; Fortin, R.; Foster, J. M.; Fox, H.; Fraser, T. J.; Freestone, J.; French, R.; Fuster, J.; Gadomski, S.; Gallop, B. J.; García, C.; Garcia-Navarro, J. E.; Gibson, M. D.; Gibson, S.; Gilchriese, M. G. D.; Godlewski, J.; Gonzalez-Sevilla, S.; Goodrick, M. J.; Gorisek, A.; Gornicki, E.; Greenall, A.; Grigson, C.; Grillo, A. A.; Grosse-Knetter, J.; Haber, C.; Hara, K.; Hartjes, F. G.; Hauff, D.; Hawes, B. M.; Haywood, S. J.; Hessey, N. P.; Hicheur, A.; Hill, J. C.; Hollins, T. I.; Holt, R.; Howell, D. F.; Hughes, G.; Huse, T.; Ibbotson, M.; Ikegami, Y.; Issever, C.; Jackson, J. N.; Jakobs, K.; Jarron, P.; Johansen, L. G.; Jones, T. J.; Jones, T. W.; de Jong, P.; Joos, D.; Jovanovic, P.; Kachiguine, S.; Kaplon, J.; Kato, Y.; Ketterer, C.; Kobayashi, H.; Kodys, P.; Koffeman, E.; Kohout, Z.; Kohriki, T.; Kondo, T.; Koperny, S.; Kramberger, G.; Kubik, P.; Kudlaty, J.; Kuwano, T.; Lacasta, C.; LaMarra, D.; Lane, J. B.; Lee, S.-C.; Lester, C. G.; Limper, M.; Lindsay, S.; Llatas, M. C.; Loebinger, F. K.; Lozano, M.; Ludwig, I.; Ludwig, J.; Lutz, G.; Lys, J.; Maassen, M.; Macina, D.; Macpherson, A.; MacWaters, C.; McMahon, S. J.; McMahon, T. J.; Magrath, C. A.; Malecki, P.; Mandić, I.; Mangin-Brinet, M.; Martí-García, S.; Martinez-Mckinney, G. F. M.; Matheson, J. M. C.; Matson, R. M.; Meinhardt, J.; Mikulec, B.; Mikuž, M.; Minagawa, M.; Mistry, J.; Mitsou, V.; Modesto, P.; Moëd, S.; Mohn, B.; Moorhead, G.; Morin, J.; Morris, J.; Morrissey, M.; Moser, H.-G.; Muijs, A. J. M.; Murray, W. J.; Nagai, K.; Nakamura, K.; Nakamura, Y.; Nakano, I.; Nichols, A.; Nicholson, R.; Nickerson, R. B.; Nisius, R.; O'Shea, V.; Oye, O. K.; Palmer, M. J.; Parker, M. A.; Parzefall, U.; Pater, J. R.; Peeters, S. J. M.; Pellegrini, G.; Pernegger, H.; Perrin, E.; Phillips, A.; Phillips, P. W.; Poltorak, K.; Pospisil, S.; Postranecky, M.; Pritchard, T.; Rafi, J. M.; Ratoff, P. N.; Reznicek, P.; Richter, R. H.; Robinson, D.; Roe, S.; Rosenbaum, F.; Rudge, A.; Runge, K.; Sadrozinski, H. F. W.; Sandaker, H.; Saxon, D. H.; Schieck, J.; Sedlak, K.; Seiden, A.; Sengoku, H.; Sfyrla, A.; Shimma, S.; Smith, K. M.; Smith, N. A.; Snow, S. W.; Solar, M.; Solberg, A.; Sopko, B.; Sospedra, L.; Spencer, E.; Stanecka, E.; Stapnes, S.; Stastny, J.; Stodulski, M.; Stugu, B.; Szczygiel, R.; Tanaka, R.; Tappern, G.; Taylor, G.; Teng, P. K.; Terada, S.; Thompson, R. J.; Titov, M.; Toczek, B.; Tovey, D. R.; Tricoli, A.; Turala, M.; Turner, P. R.; Tyndel, M.; Ullán, M.; Unno, Y.; Van der Kraaij, E.; van Vulpen, I.; Viehhauser, G.; Villani, E. G.; Vorobel, V.; Vos, M.; Wallny, R.; Warren, M. R. M.; Wastie, R. L.; Weber, M.; Weidberg, A. R.; Weilhammer, P.; Wells, P. S.; Wilder, M.; Wilhelm, I.; Wilson, J. A.; Wolter, M.

    2006-12-01

    This paper describes the silicon microstrip modules in the barrel section of the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The module requirements, components and assembly techniques are given, as well as first results of the module performance on the fully assembled barrels that make up the detector being installed in the ATLAS experiment.

  3. Autonomous Formation Flight

    NASA Technical Reports Server (NTRS)

    Schkolnik, Gerard S.; Cobleigh, Brent

    2004-01-01

    NASA's Strategic Plan for the Aerospace Technology Enterprise includes ambitious objectives focused on affordable air travel, reduced emissions, and expanded aviation-system capacity. NASA Dryden Flight Research Center, in cooperation with NASA Ames Research Center, the Boeing Company, and the University of California, Los Angeles, has embarked on an autonomous-formation-flight project that promises to make significant strides towards these goals. For millions of years, birds have taken advantage of the aerodynamic benefit of flying in formation. The traditional "V" formation flown by many species of birds (including gulls, pelicans, and geese) enables each of the trailing birds to fly in the upwash flow field that exists just outboard of the bird immediately ahead in the formation. The result for each trailing bird is a decrease in induced drag and thus a reduction in the energy needed to maintain a given speed. Hence, for migratory birds, formation flight extends the range of the system of birds over the range of birds flying solo. The Autonomous Formation Flight (AFF) Project is seeking to extend this symbiotic relationship to aircraft.

  4. Learning for Autonomous Navigation

    NASA Technical Reports Server (NTRS)

    Angelova, Anelia; Howard, Andrew; Matthies, Larry; Tang, Benyang; Turmon, Michael; Mjolsness, Eric

    2005-01-01

    Robotic ground vehicles for outdoor applications have achieved some remarkable successes, notably in autonomous highway following (Dickmanns, 1987), planetary exploration (1), and off-road navigation on Earth (1). Nevertheless, major challenges remain to enable reliable, high-speed, autonomous navigation in a wide variety of complex, off-road terrain. 3-D perception of terrain geometry with imaging range sensors is the mainstay of off-road driving systems. However, the stopping distance at high speed exceeds the effective lookahead distance of existing range sensors. Prospects for extending the range of 3-D sensors is strongly limited by sensor physics, eye safety of lasers, and related issues. Range sensor limitations also allow vehicles to enter large cul-de-sacs even at low speed, leading to long detours. Moreover, sensing only terrain geometry fails to reveal mechanical properties of terrain that are critical to assessing its traversability, such as potential for slippage, sinkage, and the degree of compliance of potential obstacles. Rovers in the Mars Exploration Rover (MER) mission have got stuck in sand dunes and experienced significant downhill slippage in the vicinity of large rock hazards. Earth-based off-road robots today have very limited ability to discriminate traversable vegetation from non-traversable vegetation or rough ground. It is impossible today to preprogram a system with knowledge of these properties for all types of terrain and weather conditions that might be encountered.

  5. Autonomic Responses to Microgravity

    NASA Technical Reports Server (NTRS)

    Toscano, W. B.; Cowings, P. S.; Miller, N. E.

    1994-01-01

    The purpose of this report is to describe how changes in autonomic nervous system responses may be used as an index of individual differences in adaptational capacity to space flight. During two separate Spacelab missions, six crewmembers wore an ambulatory monitoring system which enabled continuous recording of their physiological responses for up to twelve hours a day for 3 to 5 mission days. The responses recorded were electrocardiography, respiration wave form, skin conductance level, hand temperature, blood flow to the hands and triaxial accelerations of the head and upper body. Three of these subjects had been given training, before the mission, in voluntary control of these autonomic responses as a means of facilitating adaptation to space. Three of these subjects served as Controls, i.e., did not receive this training but took anti-motion sickness medication. Nearly 300 hours of flight data are summarized. These data were examined using time-series analyses, spectral analyses of heart rate variability, and analyses of variance. Information was obtained on responses to space motion sickness, inflight medications, circadian rhythm, workload and fatigue. Preliminary assessment was made on the effectiveness of self-regulation training as a means of facilitating adaptation, with recommendations for future flights.

  6. Autonomous mobile communication relays

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoa G.; Everett, Hobart R.; Manouk, Narek; Verma, Ambrish

    2002-07-01

    Maintaining a solid radio communication link between a mobile robot entering a building and an external base station is a well-recognized problem. Modern digital radios, while affording high bandwidth and Internet-protocol-based automatic routing capabilities, tend to operate on line-of-sight links. The communication link degrades quickly as a robot penetrates deeper into the interior of a building. This project investigates the use of mobile autonomous communication relay nodes to extend the effective range of a mobile robot exploring a complex interior environment. Each relay node is a small mobile slave robot equipped with sonar, ladar, and 802.11b radio repeater. For demonstration purposes, four Pioneer 2-DX robots are used as autonomous mobile relays, with SSC-San Diego's ROBART III acting as the lead robot. The relay robots follow the lead robot into a building and are automatically deployed at various locations to maintain a networked communication link back to the remote operator. With their on-board external sensors, they also act as rearguards to secure areas already explored by the lead robot. As the lead robot advances and RF shortcuts are detected, relay nodes that become unnecessary will be reclaimed and reused, all transparent to the operator. This project takes advantage of recent research results from several DARPA-funded tasks at various institutions in the areas of robotic simulation, ad hoc wireless networking, route planning, and navigation. This paper describes the progress of the first six months of the project.

  7. Nemesis Autonomous Test System

    NASA Technical Reports Server (NTRS)

    Barltrop, Kevin J.; Lee, Cin-Young; Horvath, Gregory A,; Clement, Bradley J.

    2012-01-01

    A generalized framework has been developed for systems validation that can be applied to both traditional and autonomous systems. The framework consists of an automated test case generation and execution system called Nemesis that rapidly and thoroughly identifies flaws or vulnerabilities within a system. By applying genetic optimization and goal-seeking algorithms on the test equipment side, a "war game" is conducted between a system and its complementary nemesis. The end result of the war games is a collection of scenarios that reveals any undesirable behaviors of the system under test. The software provides a reusable framework to evolve test scenarios using genetic algorithms using an operation model of the system under test. It can automatically generate and execute test cases that reveal flaws in behaviorally complex systems. Genetic algorithms focus the exploration of tests on the set of test cases that most effectively reveals the flaws and vulnerabilities of the system under test. It leverages advances in state- and model-based engineering, which are essential in defining the behavior of autonomous systems. It also uses goal networks to describe test scenarios.

  8. Autonomous Flight Safety System

    NASA Technical Reports Server (NTRS)

    Ferrell, Bob; Santuro, Steve; Simpson, James; Zoerner, Roger; Bull, Barton; Lanzi, Jim

    2004-01-01

    Autonomous Flight Safety System (AFSS) is an independent flight safety system designed for small to medium sized expendable launch vehicles launching from or needing range safety protection while overlying relatively remote locations. AFSS replaces the need for a man-in-the-loop to make decisions for flight termination. AFSS could also serve as the prototype for an autonomous manned flight crew escape advisory system. AFSS utilizes onboard sensors and processors to emulate the human decision-making process using rule-based software logic and can dramatically reduce safety response time during critical launch phases. The Range Safety flight path nominal trajectory, its deviation allowances, limit zones and other flight safety rules are stored in the onboard computers. Position, velocity and attitude data obtained from onboard global positioning system (GPS) and inertial navigation system (INS) sensors are compared with these rules to determine the appropriate action to ensure that people and property are not jeopardized. The final system will be fully redundant and independent with multiple processors, sensors, and dead man switches to prevent inadvertent flight termination. AFSS is currently in Phase III which includes updated algorithms, integrated GPS/INS sensors, large scale simulation testing and initial aircraft flight testing.

  9. Guide star targeting success for the HEAO-B observatory

    NASA Technical Reports Server (NTRS)

    Farrenkopf, R. L.; Hoffman, D. P.

    1977-01-01

    The statistics associated with the successful selection and acquisition of guide stars as attitude benchmarks for use in reorientation maneuvers of the HEAO-B observatory are considered as a function of the maneuver angle, initial attitude uncertainties, and the pertinent celestial region. Success likelihoods in excess of 0.99 are predicted assuming anticipated gyro and star tracker error sources. The maneuver technique and guide star selection constraints are described in detail. The results presented are specialized numerically to the HEAO-B observatory. However, the analytical techniques developed are considered applicable to broader classes of spacecraft requiring celestial targeting.

  10. Asteroid Exploration with Autonomic Systems

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt; Rash, James; Rouff, Christopher; Hinchey, Mike

    2004-01-01

    NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. The prospective ANTS (Autonomous Nano Technology Swarm) mission comprises autonomous agents including worker agents (small spacecra3) designed to cooperate in asteroid exploration under the overall authoriq of at least one ruler agent (a larger spacecraft) whose goal is to cause science data to be returned to Earth. The ANTS team (ruler plus workers and messenger agents), but not necessarily any individual on the team, will exhibit behaviors that qualify it as an autonomic system, where an autonomic system is defined as a system that self-reconfigures, self-optimizes, self-heals, and self-protects. Autonomic system concepts lead naturally to realistic, scalable architectures rich in capabilities and behaviors. In-depth consideration of a major mission like ANTS in terms of autonomic systems brings new insights into alternative definitions of autonomic behavior. This paper gives an overview of the ANTS mission and discusses the autonomic properties of the mission.

  11. Expanded Perspectives on Autonomous Learners

    ERIC Educational Resources Information Center

    Oxford, Rebecca L.

    2015-01-01

    This paper explores two general perspectives on autonomous learners: psychological and sociocultural. These perspectives introduce a range of theoretically grounded facets of autonomous learners, facets such as the self-regulated learner, the emotionally intelligent learner, the self-determined learner, the mediated learner, the socioculturally…

  12. Massive Stars

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Villaver, Eva

    2009-11-01

    Participants; Preface Mario Livio and Eva Villaver; 1. High-mass star formation by gravitational collapse of massive cores M. R. Krumholz; 2. Observations of massive star formation N. A. Patel; 3. Massive star formation in the Galactic center D. F. Figer; 4. An X-ray tour of massive star-forming regions with Chandra L. K. Townsley; 5. Massive stars: feedback effects in the local universe M. S. Oey and C. J. Clarke; 6. The initial mass function in clusters B. G. Elmegreen; 7. Massive stars and star clusters in the Antennae galaxies B. C. Whitmore; 8. On the binarity of Eta Carinae T. R. Gull; 9. Parameters and winds of hot massive stars R. P. Kudritzki and M. A. Urbaneja; 10. Unraveling the Galaxy to find the first stars J. Tumlinson; 11. Optically observable zero-age main-sequence O stars N. R. Walborn; 12. Metallicity-dependent Wolf-Raynet winds P. A. Crowther; 13. Eruptive mass loss in very massive stars and Population III stars N. Smith; 14. From progenitor to afterlife R. A. Chevalier; 15. Pair-production supernovae: theory and observation E. Scannapieco; 16. Cosmic infrared background and Population III: an overview A. Kashlinsky.

  13. STAR System.

    ERIC Educational Resources Information Center

    Doverspike, James E.

    The STAR System is a developmental guidance approach to be used with elementary school children in the 5th or 6th grades. Two basic purposes underlie STAR: to increase learning potential and to enhance personal growth and development. STAR refers to 4 basic skills: sensory, thinking, adapting, and revising. Major components of the 4 skills are:…

  14. [Autonomic features in Parkinson disease].

    PubMed

    Yamamoto, Toshimasa; Tamura, Naotoshi

    2012-04-01

    Nonmotor symptoms such as autonomic and neuropsychiatric dysfunctions, are commonly seen in Parkinson disease (PD). Recent studies have shown that PD is accompanied by cardiac sympathetic denervation and constipation even in the early stage. Neuropathological studies confirmed changes in the cardiac sympathetic nerves and the gastrointestinal tract. These findings suggest that PD neuropathology may occur first in the peripheral autonomic pathways and extend to the central autonomic pathways, in agreement with the "Braak theory". This article will reviews the symptoms and pathophysiology of gastrointestinal dysfunction, urinary disturbance, sexual dysfunction, sweating dysfunction, pupillary autonomic dysfunction, and orthostatic and postprandial hypotension in PD patients, and discuss to organ selectiveness in autonomic dysfunction in PD. PMID:22481512

  15. CH Stars and Barium Stars

    NASA Astrophysics Data System (ADS)

    Bond, H.; Sion, E.; Murdin, P.

    2000-11-01

    The classical barium (or `Ba II') stars are RED GIANT STARS whose spectra show strong absorption lines of barium, strontium and certain other heavy elements, as well as strong features due to carbon molecules. Together with the related class of CH stars, the Ba II stars were crucial in establishing the existence of neutron-capture reactions in stellar interiors that are responsible for the synt...

  16. Autonomous docking ground demonstration

    NASA Technical Reports Server (NTRS)

    Lamkin, Steve L.; Le, Thomas Quan; Othon, L. T.; Prather, Joseph L.; Eick, Richard E.; Baxter, Jim M.; Boyd, M. G.; Clark, Fred D.; Spehar, Peter T.; Teters, Rebecca T.

    1991-01-01

    The Autonomous Docking Ground Demonstration is an evaluation of the laser sensor system to support the docking phase (12 ft to contact) when operated in conjunction with the guidance, navigation, and control (GN&C) software. The docking mechanism being used was developed for the Apollo/Soyuz Test Program. This demonstration will be conducted using the 6-DOF Dynamic Test System (DTS). The DTS simulates the Space Station Freedom as the stationary or target vehicle and the Orbiter as the active or chase vehicle. For this demonstration, the laser sensor will be mounted on the target vehicle and the retroflectors will be on the chase vehicle. This arrangement was chosen to prevent potential damage to the laser. The laser sensor system, GN&C, and 6-DOF DTS will be operated closed-loop. Initial conditions to simulate vehicle misalignments, translational and rotational, will be introduced within the constraints of the systems involved.

  17. Autonomous Flying Controls Testbed

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.

    2005-01-01

    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  18. Autonomous Mission Operations for Sensor Webs

    NASA Astrophysics Data System (ADS)

    Underbrink, A.; Witt, K.; Stanley, J.; Mandl, D.

    2008-12-01

    We present interim results of a 2005 ROSES AIST project entitled, "Using Intelligent Agents to Form a Sensor Web for Autonomous Mission Operations", or SWAMO. The goal of the SWAMO project is to shift the control of spacecraft missions from a ground-based, centrally controlled architecture to a collaborative, distributed set of intelligent agents. The network of intelligent agents intends to reduce management requirements by utilizing model-based system prediction and autonomic model/agent collaboration. SWAMO agents are distributed throughout the Sensor Web environment, which may include multiple spacecraft, aircraft, ground systems, and ocean systems, as well as manned operations centers. The agents monitor and manage sensor platforms, Earth sensing systems, and Earth sensing models and processes. The SWAMO agents form a Sensor Web of agents via peer-to-peer coordination. Some of the intelligent agents are mobile and able to traverse between on-orbit and ground-based systems. Other agents in the network are responsible for encapsulating system models to perform prediction of future behavior of the modeled subsystems and components to which they are assigned. The software agents use semantic web technologies to enable improved information sharing among the operational entities of the Sensor Web. The semantics include ontological conceptualizations of the Sensor Web environment, plus conceptualizations of the SWAMO agents themselves. By conceptualizations of the agents, we mean knowledge of their state, operational capabilities, current operational capacities, Web Service search and discovery results, agent collaboration rules, etc. The need for ontological conceptualizations over the agents is to enable autonomous and autonomic operations of the Sensor Web. The SWAMO ontology enables automated decision making and responses to the dynamic Sensor Web environment and to end user science requests. The current ontology is compatible with Open Geospatial Consortium (OGC

  19. Cybersecurity for aerospace autonomous systems

    NASA Astrophysics Data System (ADS)

    Straub, Jeremy

    2015-05-01

    High profile breaches have occurred across numerous information systems. One area where attacks are particularly problematic is autonomous control systems. This paper considers the aerospace information system, focusing on elements that interact with autonomous control systems (e.g., onboard UAVs). It discusses the trust placed in the autonomous systems and supporting systems (e.g., navigational aids) and how this trust can be validated. Approaches to remotely detect the UAV compromise, without relying on the onboard software (on a potentially compromised system) as part of the process are discussed. How different levels of autonomy (task-based, goal-based, mission-based) impact this remote characterization is considered.

  20. STAR upgrade program and future physics

    NASA Astrophysics Data System (ADS)

    Wang, Yaping; Star Collaboration

    2014-09-01

    In this paper, we will present STAR's future plan in terms of both the detector upgrade and physics measurement to study matter with colour degrees of freedom. We will first discuss the status of the newly installed Heavy Flavor Tracker and Muon Telescope Detector, and their physics prospect in 2014-2016. We will then describe the proposed detector upgrades for the second phase of Beam Energy Scan program in 2018-2019 to study the QCD phase diagram. Finally we will present STAR's plan with detector upgrades in the forward directions for the anticipated pp/pA physics program in 2021-2022 and ep/eA in 2025+. The upgraded STAR experiment will be in an excellent position to perform precision measurements of the partonic structures of the nucleon and nuclei.

  1. Autonomous optical navigation for interplanetary missions

    NASA Astrophysics Data System (ADS)

    Bhaskaran, Shyam; Riedel, Joseph E.; Synnott, Stephen P.

    1996-10-01

    The automation of interplanetary spacecraft is becoming increasingly desirable to meet various mission requirements. A prototype autonomous spacecraft which will flyby an asteroid and comet is slated for flight in mid-1998 as part of NASA's New Millennium Program. This spacecraft will navigate by using optical data taken by the onboard camera to determine its orbit, and use this information to predict its future trajectory and make necessary course corrections. The basic navigation data available from the camera are star-relative astrometric observations of solar system bodies which can be used to determine line-of-sight vectors to those objects. The directional sightings are obtained by determining the precise centers of the object and stars in the image. During interplanetary cruise, centerfinding is performed by using two pattern matching techniques inherited from the Galileo mission. Near-encounter images are processed with a separate algorithm employing image modeling and brightness centroiding. This paper describes the image processing algorithms, and the results of a ground-based test of the algorithms using real data.

  2. Development of a scintillating fiber tracker for the SSC

    SciTech Connect

    Lewis, R.A.

    1992-10-01

    The Fiber Tracking Group (FTG) of the Solenoidal Detector Collaboration (SDC) is developing a high rate tracking subsystem appropriate for the SDC detector based on scintillating fiber (SciFi) technology. In the past two years a major upgrade in the design was conceived, which reduces the material and cost of the tracker and improves the effectiveness of the tracking system as a trigger element. The results of simulations of the performance of the tracker at Penn State have been very important in keeping the SciFi technology as an attractive option for a tracking system for the SDC collaboration. In the past year an array of scintillating fiber elements has been evaluated in a test beam at Brookhaven. Past experience of Penn State personnel at Brookhaven proved valuable in making the test beam runs a success.

  3. TMT tertiary mirror axis calibration with laser tracker

    NASA Astrophysics Data System (ADS)

    An, Qi-chang; Zhang, Jing-xu; Yang, Fei; Sun, Jing-wei

    2015-03-01

    To calibrate the tracing performance of the thirty meter telescope (TMT) tertiary mirror, for the special requirement of the TMT, the laser tracker is used to verify the motion. Firstly, the deviation is divided into two parts, namely, the repeatable error and the unrepeatable part. Then, based on the laser tracker, the mearturement and evalutation methods of the rigid body motion for the mirror are established, and the Monte Carol method is used to determine the accuracy of the mothod. Lastly, the mothod is applied to the turn table of a classical telescope and the residual error is about 4 arc second. The work of this paper will guide the next desgin and construction work of the thirty meter telescope tertiary mirror.

  4. Commissioning of the ATLAS Semiconductor Tracker with cosmic rays

    NASA Astrophysics Data System (ADS)

    Stanecka, E.; Atlas Sct Collaboration

    2007-10-01

    This paper presents the results of the tests with cosmic rays of the ATLAS Semiconductor Tracker (SCT) as well as operational experience of running the fully integrated silicon detector during the commissioning of the completed SCT. Prior to inserting into ATLAS, the barrel part of the SCT has been integrated with the Transition Radiation Tracker (TRT) barrel and tested with cosmic rays. A sector of 468 SCT modules has been powered and read simultaneously with TRT modules in physics mode. In total 500 thousand events were recorded during cosmic runs and processed with the ATLAS off-line reconstruction software. The SCT performance was measured in terms of the average noise occupancy per channel (4.5×10-5) and the overall efficiency (>99%). The tests with cosmic rays proved full functionality of the complex Detector Control System (DCS) which provides control, monitoring and safety functions for the detector electronics.

  5. The silicon microstrip sensors of the ATLAS semiconductor tracker

    SciTech Connect

    ATLAS SCT Collaboration; Spieler, Helmuth G.

    2007-04-13

    This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the Semiconductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd. supplied 92.2percent of the 15,392 installed sensors, with the remainder supplied by CiS.

  6. VERSATILE TWO-AXIS OPEN-LOOP SOLAR TRACKER CONTROLLER*

    SciTech Connect

    Ward, Christina D; Maxey, L Curt; Evans III, Boyd Mccutchen; Lapsa, Melissa Voss

    2008-01-01

    A versatile single-board controller for two-axis solar tracking applications has been developed and tested on operating solar tracking systems with over two years of field experience. The operating experience gained from the two systems and associated modifications are discussed as representative examples of the practical issues associated with implementing a new two-axis solar tracker design. In this research, open and closed loop control methods were evaluated; however, only the open loop method met the 0.125 tracking accuracy requirement and the requirement to maintain pointing accuracy in hazy and scattered cloudy skies. The open loop algorithm was finally implemented in a microcontroller-based tracking system. Methods of applying this controller hardware to different tracker geometries and hardware are discussed along with the experience gained to date.

  7. Tracker: Image-Processing and Object-Tracking System Developed

    NASA Technical Reports Server (NTRS)

    Klimek, Robert B.; Wright, Theodore W.

    1999-01-01

    Tracker is an object-tracking and image-processing program designed and developed at the NASA Lewis Research Center to help with the analysis of images generated by microgravity combustion and fluid physics experiments. Experiments are often recorded on film or videotape for analysis later. Tracker automates the process of examining each frame of the recorded experiment, performing image-processing operations to bring out the desired detail, and recording the positions of the objects of interest. It can load sequences of images from disk files or acquire images (via a frame grabber) from film transports, videotape, laser disks, or a live camera. Tracker controls the image source to automatically advance to the next frame. It can employ a large array of image-processing operations to enhance the detail of the acquired images and can analyze an arbitrarily large number of objects simultaneously. Several different tracking algorithms are available, including conventional threshold and correlation-based techniques, and more esoteric procedures such as "snake" tracking and automated recognition of character data in the image. The Tracker software was written to be operated by researchers, thus every attempt was made to make the software as user friendly and self-explanatory as possible. Tracker is used by most of the microgravity combustion and fluid physics experiments performed by Lewis, and by visiting researchers. This includes experiments performed on the space shuttles, Mir, sounding rockets, zero-g research airplanes, drop towers, and ground-based laboratories. This software automates the analysis of the flame or liquid s physical parameters such as position, velocity, acceleration, size, shape, intensity characteristics, color, and centroid, as well as a number of other measurements. It can perform these operations on multiple objects simultaneously. Another key feature of Tracker is that it performs optical character recognition (OCR). This feature is useful in

  8. A scintillating fibres tracker detector for archaeological applications

    NASA Astrophysics Data System (ADS)

    Menichelli, M.; Ansoldi, S.; Bari, M.; Basset, M.; Battiston, R.; Blasko, S.; Coren, F.; Fiori, E.; Giannini, G.; Iugovaz, D.; Papi, A.; Reia, S.; Scian, G.

    2007-03-01

    We designed, constructed and operated a cylindrical, scintillating fibres, tracker detector in order to measure the directional flux of cosmic ray muons underground. This instrument named Muon Ground Radiograph (MGR) was developed to study the fluctuation of the density in the soil that causes detection anisotropies in the arrival direction of cosmic ray muons observed in a tracker detector located underground. Density fluctuations may reveal hidden cavities or buried structures and can contribute to archaeological findings. The shape of the detector we used, for this purpose, is cylindrical, 14 cm diameter and 224 cm height, and it can be inserted into a 20 cm diameter hole in the ground at a maximum depth of 30 m. This paper will describe the instrument design and construction and also report some results of two observational campaigns in the town of Aquileia the Claudio and Traiano port.

  9. An isotope identification injection study with GammaTracker

    NASA Astrophysics Data System (ADS)

    Batdorf, Michael T.; Erikson, Luke E.; Seifert, Carolyn E.; Myjak, Mitchell J.; Kirihara, Leslie J.

    2011-10-01

    GammaTracker is a portable handheld radioisotope identifier using position sensitive CdZnTe detectors. High confidence isotope identification is possible on GammaTracker owing to the system's relatively high energy resolution and count rate sensitivity. A study was undertaken to evaluate the isotope identification performance of a prototype unit. Background and source spectra for various nuclides were measured and then randomly sampled to simulate various integration times and source intensities. The resulting spectral data sets were then run through the isotope identification algorithm to determine the probability of detection and the false alarm rate for each nuclide. The process was repeated for various isotope identification input parameters until an optimized set was achieved. This paper presents results from the injection study.

  10. Using Tracker as a pedagogical tool for understanding projectile motion

    NASA Astrophysics Data System (ADS)

    Wee, Loo Kang; Chew, Charles; Hwee Goh, Giam; Tan, Samuel; Lee, Tat Leong

    2012-07-01

    This article reports on the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When a computer model building learning process is supported and driven by video analysis data, this free Open Source Physics tool can provide opportunities for students to engage in active enquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions concerning projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real-life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modelling with traditional video analysis could be an innovative and effective way to learn projectile motion.

  11. Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

    SciTech Connect

    Riley, Daniel; Hansen, Clifford W.

    2014-12-30

    Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam onto the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.

  12. Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

    DOE PAGESBeta

    Riley, Daniel; Hansen, Clifford W.

    2014-12-30

    Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam ontomore » the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.« less

  13. Resonance interaction in LBNE fine-grained-tracker near detector

    NASA Astrophysics Data System (ADS)

    Duyang, Hongyue; Tian, Xinchun; Mishra, Sanjib R.

    2015-10-01

    This talk is devoted to resonance interaction (RES) in the proposed fine-grained tracker detector (FGT) for LBNE experiment. We use fast MC to study the sensitivity of FGT to RES, and use this measurement as a handle to constrain nuclear effects. Similar analysis is performed on NOMAD data for validation and better understanding. Preliminary RES measurement result using NOMAD data will be reported.

  14. Resonance interaction in LBNE fine-grained-tracker near detector

    SciTech Connect

    Duyang, Hongyue; Tian, Xinchun; Mishra, Sanjib R.

    2015-10-15

    This talk is devoted to resonance interaction (RES) in the proposed fine-grained tracker detector (FGT) for LBNE experiment. We use fast MC to study the sensitivity of FGT to RES, and use this measurement as a handle to constrain nuclear effects. Similar analysis is performed on NOMAD data for validation and better understanding. Preliminary RES measurement result using NOMAD data will be reported.

  15. Autonomous power system brassboard

    NASA Astrophysics Data System (ADS)

    Merolla, Anthony

    1992-10-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the

  16. Autonomous power system brassboard

    NASA Technical Reports Server (NTRS)

    Merolla, Anthony

    1992-01-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the

  17. Characterization of irradiated test structures for the CMS tracker upgrade

    NASA Astrophysics Data System (ADS)

    Lutzer, Bernhard

    2013-12-01

    The CMS collaboration is currently conducting a campaign to identify radiation-hard materials for an upgrade of the CMS tracker. This upgrade is needed to be able to cope with the higher radiation background of the future HL-LHC; additionally the performance of the current tracker will be significantly degraded at the time of the upgrade, requiring a replacement. Several different test structures (TSs) and sensors have been designed for a 6 in. wafer layout. These wafers were produced by an industrial supplier (Hamamatsu Photonics K.K.) and differ by their bulk material (Float Zone, Magnetic Czochralski and CVD-Epi), thickness (from 50 μm to 320 μm) and N-P type doping. These TSs consist of different microelectronic devices including diodes, resistors or MOS structures. They enable the extraction of parameters which are not accessible in a silicon detector and allow the assessment of the quality of the sensors produced on the same wafer. The TSs have been irradiated with protons and neutrons to emulate the radiation damage caused by the particle fluence inside the future CMS tracker after 10 years of operation. This contribution will present measurements of non-irradiated and irradiated test structures at different fluences. The changes of the properties of the microelectronic devices will be discussed as well as the design of the TSs.

  18. A post-processing algorithm for time domain pitch trackers

    NASA Astrophysics Data System (ADS)

    Specker, P.

    1983-01-01

    This paper describes a powerful post-processing algorithm for time-domain pitch trackers. On two successive passes, the post-processing algorithm eliminates errors produced during a first pass by a time-domain pitch tracker. During the second pass, incorrect pitch values are detected as outliers by computing the distribution of values over a sliding 80 msec window. During the third pass (based on artificial intelligence techniques), remaining pitch pulses are used as anchor points to reconstruct the pitch train from the original waveform. The algorithm produced a decrease in the error rate from 21% obtained with the original time domain pitch tracker to 2% for isolated words and sentences produced in an office environment by 3 male and 3 female talkers. In a noisy computer room errors decreased from 52% to 2.9% for the same stimuli produced by 2 male talkers. The algorithm is efficient, accurate, and resistant to noise. The fundamental frequency micro-structure is tracked sufficiently well to be used in extracting phonetic features in a feature-based recognition system.

  19. Autonomic Dysregulation in Multiple Sclerosis.

    PubMed

    Pintér, Alexandra; Cseh, Domonkos; Sárközi, Adrienn; Illigens, Ben M; Siepmann, Timo

    2015-01-01

    Multiple sclerosis (MS) is a chronic, progressive central neurological disease characterized by inflammation and demyelination. In patients with MS, dysregulation of the autonomic nervous system may present with various clinical symptoms including sweating abnormalities, urinary dysfunction, orthostatic dysregulation, gastrointestinal symptoms, and sexual dysfunction. These autonomic disturbances reduce the quality of life of affected patients and constitute a clinical challenge to the physician due to variability of clinical presentation and inconsistent data on diagnosis and treatment. Early diagnosis and initiation of individualized interdisciplinary and multimodal strategies is beneficial in the management of autonomic dysfunction in MS. This review summarizes the current literature on the most prevalent aspects of autonomic dysfunction in MS and provides reference to underlying pathophysiological mechanisms as well as means of diagnosis and treatment. PMID:26213927

  20. Autonomic closure for turbulence simulations

    NASA Astrophysics Data System (ADS)

    King, Ryan N.; Hamlington, Peter E.; Dahm, Werner J. A.

    2016-03-01

    A new approach to turbulence closure is presented that eliminates the need to specify a predefined turbulence model and instead provides for fully adaptive, self-optimizing, autonomic closures. The closure is autonomic in the sense that the simulation itself determines the optimal local, instantaneous relation between any unclosed term and resolved quantities through the solution of a nonlinear, nonparametric system identification problem. This nonparametric approach allows the autonomic closure to freely adapt to varying nonlinear, nonlocal, nonequilibrium, and other turbulence characteristics in the flow. Even a simple implementation of the autonomic closure for large eddy simulations provides remarkably more accurate results in a priori tests than do dynamic versions of traditional prescribed closures.

  1. Autonomic closure for turbulence simulations.

    PubMed

    King, Ryan N; Hamlington, Peter E; Dahm, Werner J A

    2016-03-01

    A new approach to turbulence closure is presented that eliminates the need to specify a predefined turbulence model and instead provides for fully adaptive, self-optimizing, autonomic closures. The closure is autonomic in the sense that the simulation itself determines the optimal local, instantaneous relation between any unclosed term and resolved quantities through the solution of a nonlinear, nonparametric system identification problem. This nonparametric approach allows the autonomic closure to freely adapt to varying nonlinear, nonlocal, nonequilibrium, and other turbulence characteristics in the flow. Even a simple implementation of the autonomic closure for large eddy simulations provides remarkably more accurate results in a priori tests than do dynamic versions of traditional prescribed closures. PMID:27078285

  2. Autonomic disorders predicting Parkinson disease

    PubMed Central

    Palma, Jose-Alberto; Kaufmann, Horacio

    2014-01-01

    It is now well recognized that there is a premotor phase of Parkinson disease with hyposmia and REM sleep behavior disorder caused by degeneration of specific CNS neurons. Most patients with PD describe autonomic symptoms at the time of diagnosis suggesting that these features may have potential sensitivity as clinical biomarkers of the premotor phase. The recognition that damage to peripheral autonomic neurons is present in the early stages of Parkinson disease has led to a search for specific abnormalities in autonomic function that could serve as predictive biomarkers. There is evidence that constipation, urinary and sexual dysfunction and more recently decreased cardiac chronotropic response during exercise, are part of the premotor parkinsonian phenotype. The sensitivity and specificity of these features has yet to be accurately assessed. We briefly review the evidence for autonomic dysfunction as biomarkers of premotor PD. PMID:24262198

  3. Autonomic Dysregulation in Multiple Sclerosis

    PubMed Central

    Pintér, Alexandra; Cseh, Domonkos; Sárközi, Adrienn; Illigens, Ben M.; Siepmann, Timo

    2015-01-01

    Multiple sclerosis (MS) is a chronic, progressive central neurological disease characterized by inflammation and demyelination. In patients with MS, dysregulation of the autonomic nervous system may present with various clinical symptoms including sweating abnormalities, urinary dysfunction, orthostatic dysregulation, gastrointestinal symptoms, and sexual dysfunction. These autonomic disturbances reduce the quality of life of affected patients and constitute a clinical challenge to the physician due to variability of clinical presentation and inconsistent data on diagnosis and treatment. Early diagnosis and initiation of individualized interdisciplinary and multimodal strategies is beneficial in the management of autonomic dysfunction in MS. This review summarizes the current literature on the most prevalent aspects of autonomic dysfunction in MS and provides reference to underlying pathophysiological mechanisms as well as means of diagnosis and treatment. PMID:26213927

  4. ISS Update: Autonomous Mission Operations

    NASA Video Gallery

    NASA Public Affairs Officer Brandi Dean interviews Jeff Mauldin, Simulation Supervisor for Autonomous Mission Operations at Johnson Space Center in Houston, Texas. Ask us on Twitter @NASA_Johnson a...

  5. Autonomous Landing Hazard Avoidance Technology

    NASA Video Gallery

    Future NASA space crafts will be able to safely land on the Moon, Marsand even an asteroid, in potentially hazardous terrain areas, allautonomously. And NASA’s Autonomous Landing Hazard Avoidan...

  6. Flight Mechanics/Estimation Theory Symposium. [with application to autonomous navigation and attitude/orbit determination

    NASA Technical Reports Server (NTRS)

    Fuchs, A. J. (Editor)

    1979-01-01

    Onboard and real time image processing to enhance geometric correction of the data is discussed with application to autonomous navigation and attitude and orbit determination. Specific topics covered include: (1) LANDSAT landmark data; (2) star sensing and pattern recognition; (3) filtering algorithms for Global Positioning System; and (4) determining orbital elements for geostationary satellites.

  7. Autonomous Gaussian Decomposition

    NASA Astrophysics Data System (ADS)

    Lindner, Robert R.; Vera-Ciro, Carlos; Murray, Claire E.; Stanimirović, Snežana; Babler, Brian; Heiles, Carl; Hennebelle, Patrick; Goss, W. M.; Dickey, John

    2015-04-01

    We present a new algorithm, named Autonomous Gaussian Decomposition (AGD), for automatically decomposing spectra into Gaussian components. AGD uses derivative spectroscopy and machine learning to provide optimized guesses for the number of Gaussian components in the data, and also their locations, widths, and amplitudes. We test AGD and find that it produces results comparable to human-derived solutions on 21 cm absorption spectra from the 21 cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the H i line completeness as a function of peak optical depth and velocity width for the 21-SPONGE data, and also show that the results of AGD are stable against varying observational noise intensity. The autonomy and computational efficiency of the method over traditional manual Gaussian fits allow for truly unbiased comparisons between observations and simulations, and for the ability to scale up and interpret the very large data volumes from the upcoming Square Kilometer Array and pathfinder telescopes.

  8. Autonomous landing guidance program

    NASA Astrophysics Data System (ADS)

    Brown, John A.

    1996-05-01

    The Autonomous Landing Guidance program is partly funded by the US Government under the Technology Reinvestment Project. The program consortium consists of avionics and other equipment vendors, airlines and the USAF. A Sextant Avionique HUD is used to present flight symbology in cursive form as well as millimeter wave radar imagery from Lear Astronics equipment and FLIR Systems dual-channel, forward-looking, infrared imagery. All sensor imagery is presented in raster form. A future aim is to fuse all imagery data into a single presentation. Sensor testing has been accomplished in a Cessna 402 operated by the Maryland Advanced Development Laboratory. Development testing is under way in a Northwest Airlines simulator equipped with HUD and image simulation. Testing is also being carried out using United Airlines Boeing 727 and USAF C-135C (Boeing 707) test aircraft. The paper addresses the technology utilized in sensory and display systems as well as modifications made to accommodate the elements in the aircraft. Additions to the system test aircraft include global positioning systems, inertial navigation systems and extensive data collection equipment. Operational philosophy and benefits for both civil and military users are apparent. Approach procedures have been developed allowing use of Category 1 ground installations in Category 3 conditions.

  9. Autonomous underwater barcode recognition

    NASA Astrophysics Data System (ADS)

    Schulze, Karl R.

    2003-11-01

    Wide area symbol recognition is a task that plagues many autonomous vehicles. A process is needed first to recognize if the symbol is present, and if so where it is. Once the symbol's position is detected it must be analyzed and recognized. In this scenario we have a submersible attempting to locate man made objects on the bottom of a large water basin. These man made objects have bar codes on them that need to be read and the position of the code needs to be recorded relative to where it is in the entire pond. A two step process has been developed to allow the position recognition within a frame to be dealt with on a separate DSP associated with one of three total cameras. The object recognition is then dealt with on a high speed computer aboard the vehicle to read the proper code. The reading is done using a statistics based approach that assumes a noisy, but contrasting background. This approach has proven to be effective in environments in which the background has very little ordered noise, such as the bottom of lakes and ponds, but requires very high clarity in order to capture a suitable image.

  10. Autonomous mission operations

    NASA Astrophysics Data System (ADS)

    Frank, J.; Spirkovska, L.; McCann, R.; Wang, Lui; Pohlkamp, K.; Morin, L.

    NASA's Advanced Exploration Systems Autonomous Mission Operations (AMO) project conducted an empirical investigation of the impact of time delay on today's mission operations, and of the effect of processes and mission support tools designed to mitigate time-delay related impacts. Mission operation scenarios were designed for NASA's Deep Space Habitat (DSH), an analog spacecraft habitat, covering a range of activities including nominal objectives, DSH system failures, and crew medical emergencies. The scenarios were simulated at time delay values representative of Lunar (1.2-5 sec), Near Earth Object (NEO) (50 sec) and Mars (300 sec) missions. Each combination of operational scenario and time delay was tested in a Baseline configuration, designed to reflect present-day operations of the International Space Station, and a Mitigation configuration in which a variety of software tools, information displays, and crew-ground communications protocols were employed to assist both crews and Flight Control Team (FCT) members with the long-delay conditions. Preliminary findings indicate: 1) Workload of both crewmembers and FCT members generally increased along with increasing time delay. 2) Advanced procedure execution viewers, caution and warning tools, and communications protocols such as text messaging decreased the workload of both flight controllers and crew, and decreased the difficulty of coordinating activities. 3) Whereas crew workload ratings increased between 50 sec and 300 sec of time delay in the Baseline configuration, workload ratings decreased (or remained flat) in the Mitigation configuration.

  11. Simple autonomous Mars walker

    NASA Technical Reports Server (NTRS)

    Larimer, Stanley J.; Lisec, Thomas R.; Spiessbach, Andrew J.

    1989-01-01

    Under a contract with NASA's Jet Propulsion Laboratory, Martin Marietta has developed several alternative rover concepts for unmanned exploration of the planet Mars. One of those concepts, the 'Walking Beam', is the subject of this paper. This concept was developed with the goal of achieving many of the capabilities of more sophisticated articulated-leg walkers with a much simpler, more robust, less computationally demanding and more power efficient design. It consists of two large-base tripods nested one within the other which alternately translate with respect to each other along a 5-meter beam to propel the vehicle. The semiautonomous navigation system relies on terrain geometry sensors and tacticle feedback from each foot to autonomously select a path which avoids hazards along a route designated from earth. Both mobility and navigation features of this concept are discussed including a top-level description of the vehicle's physical characteristics, deployment strategy, mobility elements, sensor suite, theory of operation, navigation and control processes, and estimated performance.

  12. Is paramecium swimming autonomic?

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Promode R.; Toplosky, Norman; Hansen, Joshua

    2010-11-01

    We seek to explore if the swimming of paramecium has an underlying autonomic mechanism. Such robotic elements may be useful in capturing the disturbance field in an environment in real time. Experimental evidence is emerging that motion control neurons of other animals may be present in paramecium as well. The limit cycle determined using analog simulation of the coupled nonlinear oscillators of olivo-cerebellar dynamics (ieee joe 33, 563-578, 2008) agrees with the tracks of the cilium of a biological paramecium. A 4-motor apparatus has been built that reproduces the kinematics of the cilium motion. The motion of the biological cilium has been analyzed and compared with the results of the finite element modeling of forces on a cilium. The modeling equates applied torque at the base of the cilium with drag, the cilium stiffness being phase dependent. A low friction pendulum apparatus with a multiplicity of electromagnetic actuators is being built for verifying the maps of the attractor basin computed using the olivo-cerebellar dynamics for different initial conditions. Sponsored by ONR 33.

  13. Autonomous Aerobraking at Mars

    NASA Technical Reports Server (NTRS)

    Hanna, Jill L.; Tolson, Robert; Cianciolo, Alicia Dwyer; Dec, John

    2002-01-01

    Aerobraking has become a proven approach for orbital missions at Mars. A launch of a 1000 kg class spacecraft on a Delta class booster saves 90% of the post-MOI fuel otherwise required to circularize the orbit. In 1997, Mars Global Surveyor demonstrated the feasibility and Mars 2001 Odyssey completed a nearly trouble free aerobraking phase in January 2002. In 2006, Mars Reconnaissance Orbiter will also utilize aerobraking. From the flight operations standpoint, however, aerobraking is labor intensive and high risk due to the large density variability in the Mars thermosphere. The maximum rate of aerobraking is typically limited by the maximum allowable temperature of the solar array which is the primary drag surface. Prior missions have used a surrogate variable, usually maximum free stream heat flux, as a basis for performing periapsis altitude corridor control maneuvers. This paper provides an adaptive sequential method for operationally relating measured temperatures to heat flux profile characteristics and performing maneuvers based directly on measured temperatures and atmospheric properties derived from the heat flux profiles. Simulations of autonomous aerobraking are performed using Odyssey mission data.

  14. Autonomous production of propellants

    NASA Technical Reports Server (NTRS)

    Ramohalli, Kumar; Schallhorn, P. A.

    1990-01-01

    The autonomous production of propellants is addressed. Since 80 to 90 percent of a spacecraft's mass is typically propellants, it is advantageous to produce propellants in strategic locations en route to, and at, the desired mission destination. This reduces the weight of the spacecraft and the cost of each mission. Since one of the primary goals of the space program is safety, a totally automated propellant production system is desirable. This system would remove, from hostile, high-risk extraterrestrial environments, the constant human intervention currently required in the production of many propellants. This enables the exploration of space to be more than the search for and production of fuel. As a proof-of-concept demonstration, one specific case was chosen for this study. That case was a composite propellant processor (the principle is more important than the application), and the specific processor used saved SERC the considerable cost of acquiring a new liquid propellant processor that would also have required similar automation.

  15. Autonomous Mission Operations Roadmap

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy David

    2014-01-01

    As light time delays increase, the number of such situations in which crew autonomy is the best way to conduct the mission is expected to increase. However, there are significant open questions regarding which functions to allocate to ground and crew as the time delays increase. In situations where the ideal solution is to allocate responsibility to the crew and the vehicle, a second question arises: should the activity be the responsibility of the crew or an automated vehicle function? More specifically, we must answer the following questions: What aspects of mission operation responsibilities (Plan, Train, Fly) should be allocated to ground based or vehicle based planning, monitoring, and control in the presence of significant light-time delay between the vehicle and the Earth?How should the allocated ground based planning, monitoring, and control be distributed across the flight control team and ground system automation? How should the allocated vehicle based planning, monitoring, and control be distributed between the flight crew and onboard system automation?When during the mission should responsibility shift from flight control team to crew or from crew to vehicle, and what should the process of shifting responsibility be as the mission progresses? NASA is developing a roadmap of capabilities for Autonomous Mission Operations for human spaceflight. This presentation will describe the current state of development of this roadmap, with specific attention to in-space inspection tasks that crews might perform with minimum assistance from the ground.

  16. Autonomous power system: Integrated scheduling

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.

    1992-01-01

    The Autonomous Power System (APS) project at NASA Lewis Research Center is designed to demonstrate the abilities of integrated intelligent diagnosis, control and scheduling techniques to space power distribution hardware. The project consists of three elements: the Autonomous Power Expert System (APEX) for fault diagnosis, isolation, and recovery (FDIR), the Autonomous Intelligent Power Scheduler (AIPS) to determine system configuration, and power hardware (Brassboard) to simulate a space-based power system. Faults can be introduced into the Brassboard and in turn, be diagnosed and corrected by APEX and AIPS. The Autonomous Intelligent Power Scheduler controls the execution of loads attached to the Brassboard. Each load must be executed in a manner that efficiently utilizes available power and satisfies all load, resource, and temporal constraints. In the case of a fault situation on the Brassboard, AIPS dynamically modifies the existing schedule in order to resume efficient operation conditions. A database is kept of the power demand, temporal modifiers, priority of each load, and the power level of each source. AIPS uses a set of heuristic rules to assign start times and resources to each load based on load and resource constraints. A simple improvement engine based upon these heuristics is also available to improve the schedule efficiency. This paper describes the operation of the Autonomous Intelligent Power Scheduler as a single entity, as well as its integration with APEX and the Brassboard. Future plans are discussed for the growth of the Autonomous Intelligent Power Scheduler.

  17. Autonomous Byte Stream Randomizer

    NASA Technical Reports Server (NTRS)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  18. Star Polymers.

    PubMed

    Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

    2016-06-22

    Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings. PMID:27299693

  19. Radio stars.

    PubMed

    Hjellming, R M; Wade, C M

    1971-09-17

    Up to the present time six classes of radio stars have been established. The signals are almost always very faint and drastically variable. Hence their discovery has owed as much to serendipity as to the highly sophisticated equipment and techniques that have been used. When the variations are regular, as with the pulsars, this characteristic can be exploited very successfully in the search for new objects as well as in the detailed study of those that are already known. The detection of the most erratically variable radio stars, the flare stars and the x-ray stars, is primarily a matter of luck and patience. In the case of the novas, one at least knows where and oughly when to look for radio emission. A very sensitive interferometer is clearly the best instrument to use in the initial detection of a radio star. The fact that weak background sources are frequently present makes it essential to prove that the position of a radio source agrees with that of a star to within a few arc seconds. The potential of radio astronomy for the study of radio stars will not be realized until more powerful instruments than those that are available today can be utilized. So far, we have been able to see only the most luminous of the radio stars. PMID:17836594

  20. Performance of the Heavy Flavor Tracker (HFT) detector in star experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Alruwaili, Manal

    With the growing technology, the number of the processors is becoming massive. Current supercomputer processing will be available on desktops in the next decade. For mass scale application software development on massive parallel computing available on desktops, existing popular languages with large libraries have to be augmented with new constructs and paradigms that exploit massive parallel computing and distributed memory models while retaining the user-friendliness. Currently, available object oriented languages for massive parallel computing such as Chapel, X10 and UPC++ exploit distributed computing, data parallel computing and thread-parallelism at the process level in the PGAS (Partitioned Global Address Space) memory model. However, they do not incorporate: 1) any extension at for object distribution to exploit PGAS model; 2) the programs lack the flexibility of migrating or cloning an object between places to exploit load balancing; and 3) lack the programming paradigms that will result from the integration of data and thread-level parallelism and object distribution. In the proposed thesis, I compare different languages in PGAS model; propose new constructs that extend C++ with object distribution and object migration; and integrate PGAS based process constructs with these extensions on distributed objects. Object cloning and object migration. Also a new paradigm MIDD (Multiple Invocation Distributed Data) is presented when different copies of the same class can be invoked, and work on different elements of a distributed data concurrently using remote method invocations. I present new constructs, their grammar and their behavior. The new constructs have been explained using simple programs utilizing these constructs.

  1. Refracting lens system for low-scatter star-tracker: A Concept

    NASA Technical Reports Server (NTRS)

    1975-01-01

    ''Low Scatter Lens Design/Development'' discusses studies of low-scatter lens system. Two sections cover optical design and scattering analysis for model of lens system which rejects radiation. Result of computations are shown on computer printouts attached to report.

  2. The STAR detector magnet subsystem

    SciTech Connect

    Brown, R.L.; Etkin, A.; Foley, K.J.

    1997-07-01

    The RHIC (Relativistic Heavy Ion Collider) Accelerator currently under construction at Brookhaven National Laboratory will have large detectors at two of its six intersection regions. One of these detectors, known as STAR (Solenoidal Tracker At RHIC), weighs 1100 tons and is being built around a large solenoid magnet. The magnet is 7.32 in in diameter, 7.25 m long and utilizes three different sizes of room temperature aluminum coils. The magnet will operate with a field set from 0.25 T to 0.5 T and have a field uniformity of better than 1000 ppm over a portion of its interior region. This paper describes the magnet design, fabrication and assembly requirements and presents the current construction status.

  3. Front end electronics for the STAR TPC

    SciTech Connect

    Klein, S.R.; Barale, P.; Beuville, E.

    1995-10-01

    The Solenoidal Tracker at RHIC (STAR) is a large acceptance detector now being built to study high energy heavy ion collisions. It detects charged particles with a large time projection chamber. The 136,600 TPC pads are instrumented with waveform digitizers, implemented in custom low noise preamplifier/shaper and switched capacitor array/ADCs ICs. The system is highly integrated with all analog functions mounted on small cards that plug into the TPC. Detector mounted readout boards multiplex data from 1,152 channels onto a 1.5 Gbit/sec fiber optic link to the data acquisition system.

  4. Towards an Autonomic Cluster Management System (ACMS) with Reflex Autonomicity

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt; Hinchey, Mike; Sterritt, Roy

    2005-01-01

    Cluster computing, whereby a large number of simple processors or nodes are combined together to apparently function as a single powerful computer, has emerged as a research area in its own right. The approach offers a relatively inexpensive means of providing a fault-tolerant environment and achieving significant computational capabilities for high-performance computing applications. However, the task of manually managing and configuring a cluster quickly becomes daunting as the cluster grows in size. Autonomic computing, with its vision to provide self-management, can potentially solve many of the problems inherent in cluster management. We describe the development of a prototype Autonomic Cluster Management System (ACMS) that exploits autonomic properties in automating cluster management and its evolution to include reflex reactions via pulse monitoring.

  5. Design and analysis of the tracker bridge for the Hobby-Eberly Telescope wide-field upgrade

    NASA Astrophysics Data System (ADS)

    Worthington, Michael S.; Mollison, Nicholas T.; Soukup, Ian M.; Zierer, Joseph J.; Good, John M.; Nichols, Steven P.

    2010-07-01

    A large structural weldment has been designed to serve as the new star tracker bridge for the Wide Field Upgrade to the Hobby-Eberly Telescope at McDonald Observatory in support of the Hobby-Eberly Telescope Dark Energy Experiment‡. The modeling approach, analysis techniques and design details will be of interest to designers of large structures where stiffness is the primary design driver. The design includes detailed structural analysis using finite element models to maximize natural frequency response and limit deflections and light obscuration. Considerable fabrication challenges are overcome to allow integration of precision hardware required for positioning the corrector optics to a precision of less than 5 microns along the 4-meter travel range. Detailed descriptions of the bridge geometry, analysis results and challenging fabrication issues are discussed.

  6. Autonomic control of the eye.

    PubMed

    McDougal, David H; Gamlin, Paul D

    2015-01-01

    The autonomic nervous system influences numerous ocular functions. It does this by way of parasympathetic innervation from postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia, and by way of sympathetic innervation from postganglionic fibers that originate from neurons in the superior cervical ganglion. Ciliary ganglion neurons project to the ciliary body and the sphincter pupillae muscle of the iris to control ocular accommodation and pupil constriction, respectively. Superior cervical ganglion neurons project to the dilator pupillae muscle of the iris to control pupil dilation. Ocular blood flow is controlled both via direct autonomic influences on the vasculature of the optic nerve, choroid, ciliary body, and iris, as well as via indirect influences on retinal blood flow. In mammals, this vasculature is innervated by vasodilatory fibers from the pterygopalatine ganglion, and by vasoconstrictive fibers from the superior cervical ganglion. Intraocular pressure is regulated primarily through the balance of aqueous humor formation and outflow. Autonomic regulation of ciliary body blood vessels and the ciliary epithelium is an important determinant of aqueous humor formation; autonomic regulation of the trabecular meshwork and episcleral blood vessels is an important determinant of aqueous humor outflow. These tissues are all innervated by fibers from the pterygopalatine and superior cervical ganglia. In addition to these classical autonomic pathways, trigeminal sensory fibers exert local, intrinsic influences on many of these regions of the eye, as well as on some neurons within the ciliary and pterygopalatine ganglia. PMID:25589275

  7. Autonomic control of the eye

    PubMed Central

    McDougal, David H.; Gamlin, Paul D.

    2016-01-01

    The autonomic nervous system influences numerous ocular functions. It does this by way of parasympathetic innervation from postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia, and by way of sympathetic innervation from postganglionic fibers that originate from neurons in the superior cervical ganglion. Ciliary ganglion neurons project to the ciliary body and the sphincter pupillae muscle of the iris to control ocular accommodation and pupil constriction, respectively. Superior cervical ganglion neurons project to the dilator pupillae muscle of the iris to control pupil dilation. Ocular blood flow is controlled both via direct autonomic influences on the vasculature of the optic nerve, choroid, ciliary body, and iris, as well as via indirect influences on retinal blood flow. In mammals, this vasculature is innervated by vasodilatory fibers from the pterygopalatine ganglion, and by vasoconstrictive fibers from the superior cervical ganglion. Intraocular pressure is regulated primarily through the balance of aqueous humor formation and outflow. Autonomic regulation of ciliary body blood vessels and the ciliary epithelium is an important determinant of aqueous humor formation; autonomic regulation of the trabecular meshwork and episcleral blood vessels is an important determinant of aqueous humor outflow. These tissues are all innervated by fibers from the pterygopalatine and superior cervical ganglia. In addition to these classical autonomic pathways, trigeminal sensory fibers exert local, intrinsic influences on many of these regions of the eye, as well as on some neurons within the ciliary and pterygopalatine ganglia. PMID:25589275

  8. Inverse sparse tracker with a locally weighted distance metric.

    PubMed

    Wang, Dong; Lu, Huchuan; Xiao, Ziyang; Yang, Ming-Hsuan

    2015-09-01

    Sparse representation has been recently extensively studied for visual tracking and generally facilitates more accurate tracking results than classic methods. In this paper, we propose a sparsity-based tracking algorithm that is featured with two components: 1) an inverse sparse representation formulation and 2) a locally weighted distance metric. In the inverse sparse representation formulation, the target template is reconstructed with particles, which enables the tracker to compute the weights of all particles by solving only one l1 optimization problem and thereby provides a quite efficient model. This is in direct contrast to most previous sparse trackers that entail solving one optimization problem for each particle. However, we notice that this formulation with normal Euclidean distance metric is sensitive to partial noise like occlusion and illumination changes. To this end, we design a locally weighted distance metric to replace the Euclidean one. Similar ideas of using local features appear in other works, but only being supported by popular assumptions like local models could handle partial noise better than holistic models, without any solid theoretical analysis. In this paper, we attempt to explicitly explain it from a mathematical view. On that basis, we further propose a method to assign local weights by exploiting the temporal and spatial continuity. In the proposed method, appearance changes caused by partial occlusion and shape deformation are carefully considered, thereby facilitating accurate similarity measurement and model update. The experimental validation is conducted from two aspects: 1) self validation on key components and 2) comparison with other state-of-the-art algorithms. Results over 15 challenging sequences show that the proposed tracking algorithm performs favorably against the existing sparsity-based trackers and the other state-of-the-art methods. PMID:25935033

  9. Monitoring with Trackers Based on Semi-Quantitative Models

    NASA Technical Reports Server (NTRS)

    Kuipers, Benjamin

    1997-01-01

    In three years of NASA-sponsored research preceding this project, we successfully developed a technology for: (1) building qualitative and semi-quantitative models from libraries of model-fragments, (2) simulating these models to predict future behaviors with the guarantee that all possible behaviors are covered, (3) assimilating observations into behaviors, shrinking uncertainty so that incorrect models are eventually refuted and correct models make stronger predictions for the future. In our object-oriented framework, a tracker is an object which embodies the hypothesis that the available observation stream is consistent with a particular behavior of a particular model. The tracker maintains its own status (consistent, superceded, or refuted), and answers questions about its explanation for past observations and its predictions for the future. In the MIMIC approach to monitoring of continuous systems, a number of trackers are active in parallel, representing alternate hypotheses about the behavior of a system. This approach is motivated by the need to avoid 'system accidents' [Perrow, 1985] due to operator fixation on a single hypothesis, as for example at Three Mile Island. As we began to address these issues, we focused on three major research directions that we planned to pursue over a three-year project: (1) tractable qualitative simulation, (2) semiquantitative inference, and (3) tracking set management. Unfortunately, funding limitations made it impossible to continue past year one. Nonetheless, we made major progress in the first two of these areas. Progress in the third area as slower because the graduate student working on that aspect of the project decided to leave school and take a job in industry. I enclosed a set of abstract of selected papers on the work describe below. Several papers that draw on the research supported during this period appeared in print after the grant period ended.

  10. Physics sensitivity studies of Fine-Grained Tracker

    SciTech Connect

    Tian, Xinchun; Mishra, Sanjib R.; Petti, Roberto; Hongyue, Duyang

    2015-10-15

    The reference design of the near detector for the LBNE experiment is a high-resolution Fine-Grained Tracker (FGT). We performed sensitivity studies – critical to constraining the systematics in oscillation searches – of measurements of (1) the absolute neutrino flux, (2) neutrino-nucleon quasi-elastic (QE) and (3) resonance (Res) interactions. In QE and Res emphasis is laid in identifying in situ measurables that help constrain nuclear effects such as initial state pair wise correlations and final state interactions.

  11. Evaluating a robust contour tracker on echocardiographic sequences.

    PubMed

    Jacob, G; Noble, J A; Mulet-Parada, M; Blake, A

    1999-03-01

    In this paper we present an evaluation of a robust visual image tracker on echocardiographic image sequences. We show how the tracking framework can be customized to define an appropriate shape space that describes heart shape deformations that can be learnt from a training data set. We also investigate energy-based temporal boundary enhancement methods to improve image feature measurement. Results are presented demonstrating real-time tracking on real normal heart motion data sequences and abnormal synthesized and real heart motion data sequences. We conclude by discussing some of our current research efforts. PMID:10709697

  12. Autonomous mobile robots: Vehicles with cognitive control

    SciTech Connect

    Meystel, A.

    1987-01-01

    This book explores a new rapidly developing area of robotics. It describes the state-of-the-art intelligence control, applied machine intelligence, and research and initial stages of manufacturing of autonomous mobile robots. A complete account of the theoretical and experimental results obtained during the last two decades together with some generalizations on Autonomous Mobile Systems are included in this book. Contents: Introduction; Requirements and Specifications; State-of-the-art in Autonomous Mobile Robots Area; Structure of Intelligent Mobile Autonomous System; Planner, Navigator; Pilot; Cartographer; Actuation Control; Computer Simulation of Autonomous Operation; Testing the Autonomous Mobile Robot; Conclusions; Bibliography.

  13. Autonomous hazard detection and avoidance

    NASA Technical Reports Server (NTRS)

    Pien, Homer

    1992-01-01

    During GFY 91, Draper Laboratory was awarded a task by NASA-JSC under contract number NAS9-18426 to study and evaluate the potential for achieving safe autonomous landings on Mars using an on-board autonomous hazard detection and avoidance (AHDA) system. This report describes the results of that study. The AHDA task had four objectives: to demonstrate, via a closed-loop simulation, the ability to autonomously select safe landing sites and the ability to maneuver to the selected site; to identify key issues in the development of AHDA systems; to produce strawman designs for AHDA sensors and algorithms; and to perform initial trade studies leading to better understanding of the effect of sensor/terrain/viewing parameters on AHDA algorithm performance. This report summarizes the progress made during the first year, with primary emphasis on describing the tools developed for simulating a closed-loop AHDA landing. Some cursory performance evaluation results are also presented.

  14. Interesting aspects of the STAR detector and physics program

    SciTech Connect

    Hallman, T.J.; STAR Collaboration

    1996-12-31

    The Solenoidal Tracker At RHIC (STAR) is a large acceptance collider detector scheduled to begin operation at the Relativistic Heavy Ion Collider (RHIC) in the fall of 1999. Simply stated, the physics goals of STAR are, (1) to study the behavior of strongly interacting matter at high energy density; (2) to search for signatures of a deconfined partonic phase of matter; and (3) to study the importance of spin as a fundamental property of QCD interactions and measure the spin-dependent parton distributions (gluon, valence quark, sea quark) of the proton. The detector design and methods of accomplishing the physics goals are addressed in this report.

  15. Contingency Software in Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn; Patterson-Hine, Ann

    2006-01-01

    This viewgraph presentation reviews the development of contingency software for autonomous systems. Autonomous vehicles currently have a limited capacity to diagnose and mitigate failures. There is a need to be able to handle a broader range of contingencies. The goals of the project are: 1. Speed up diagnosis and mitigation of anomalous situations.2.Automatically handle contingencies, not just failures.3.Enable projects to select a degree of autonomy consistent with their needs and to incrementally introduce more autonomy.4.Augment on-board fault protection with verified contingency scripts

  16. Miniature Autonomous Robotic Vehicle (MARV)

    SciTech Connect

    Feddema, J.T.; Kwok, K.S.; Driessen, B.J.; Spletzer, B.L.; Weber, T.M.

    1996-12-31

    Sandia National Laboratories (SNL) has recently developed a 16 cm{sup 3} (1 in{sup 3}) autonomous robotic vehicle which is capable of tracking a single conducting wire carrying a 96 kHz signal. This vehicle was developed to assess the limiting factors in using commercial technology to build miniature autonomous vehicles. Particular attention was paid to the design of the control system to search out the wire, track it, and recover if the wire was lost. This paper describes the test vehicle and the control analysis. Presented in the paper are the vehicle model, control laws, a stability analysis, simulation studies and experimental results.

  17. Progress towards autonomous, intelligent systems

    NASA Technical Reports Server (NTRS)

    Lum, Henry; Heer, Ewald

    1987-01-01

    An aggressive program has been initiated to develop, integrate, and implement autonomous systems technologies starting with today's expert systems and evolving to autonomous, intelligent systems by the end of the 1990s. This program includes core technology developments and demonstration projects for technology evaluation and validation. This paper discusses key operational frameworks in the content of systems autonomy applications and then identifies major technological challenges, primarily in artificial intelligence areas. Program content and progress made towards critical technologies and demonstrations that have been initiated to achieve the required future capabilities in the year 2000 era are discussed.

  18. Intelligent, autonomous systems in space

    NASA Technical Reports Server (NTRS)

    Lum, H.; Heer, E.

    1988-01-01

    The Space Station is expected to be equipped with intelligent, autonomous capabilities; to achieve and incorporate these capabilities, the required technologies need to be identitifed, developed and validated within realistic application scenarios. The critical technologies for the development of intelligent, autonomous systems are discussed in the context of a generalized functional architecture. The present state of this technology implies that it be introduced and applied in an evolutionary process which must start during the Space Station design phase. An approach is proposed to accomplish design information acquisition and management for knowledge-base development.

  19. Gas House Autonomous System Monitoring

    NASA Technical Reports Server (NTRS)

    Miller, Luke; Edsall, Ashley

    2015-01-01

    Gas House Autonomous System Monitoring (GHASM) will employ Integrated System Health Monitoring (ISHM) of cryogenic fluids in the High Pressure Gas Facility at Stennis Space Center. The preliminary focus of development incorporates the passive monitoring and eventual commanding of the Nitrogen System. ISHM offers generic system awareness, adept at using concepts rather than specific error cases. As an enabler for autonomy, ISHM provides capabilities inclusive of anomaly detection, diagnosis, and abnormality prediction. Advancing ISHM and Autonomous Operation functional capabilities enhances quality of data, optimizes safety, improves cost effectiveness, and has direct benefits to a wide spectrum of aerospace applications.

  20. Discerning non-autonomous dynamics

    NASA Astrophysics Data System (ADS)

    Clemson, Philip T.; Stefanovska, Aneta

    2014-09-01

    Structure and function go hand in hand. However, while a complex structure can be relatively safely broken down into the minutest parts, and technology is now delving into nanoscales, the function of complex systems requires a completely different approach. Here the complexity clearly arises from nonlinear interactions, which prevents us from obtaining a realistic description of a system by dissecting it into its structural component parts. At best, the result of such investigations does not substantially add to our understanding or at worst it can even be misleading. Not surprisingly, the dynamics of complex systems, facilitated by increasing computational efficiency, is now readily tackled in the case of measured time series. Moreover, time series can now be collected in practically every branch of science and in any structural scale-from protein dynamics in a living cell to data collected in astrophysics or even via social networks. In searching for deterministic patterns in such data we are limited by the fact that no complex system in the real world is autonomous. Hence, as an alternative to the stochastic approach that is predominantly applied to data from inherently non-autonomous complex systems, theory and methods specifically tailored to non-autonomous systems are needed. Indeed, in the last decade we have faced a huge advance in mathematical methods, including the introduction of pullback attractors, as well as time series methods that cope with the most important characteristic of non-autonomous systems-their time-dependent behaviour. Here we review current methods for the analysis of non-autonomous dynamics including those for extracting properties of interactions and the direction of couplings. We illustrate each method by applying it to three sets of systems typical for chaotic, stochastic and non-autonomous behaviour. For the chaotic class we select the Lorenz system, for the stochastic the noise-forced Duffing system and for the non-autonomous the

  1. Hypervelocity Stars

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.

    2015-08-01

    Hypervelocity stars (HVSs) travel with such extreme velocities that dynamical ejection via gravitational interaction with a massive black hole (MBH) is their most likely origin. Observers have discovered dozens of unbound main-sequence stars since the first in 2005, and the velocities, stellar nature, spatial distribution, and overall numbers of unbound B stars in the Milky Way halo all fit an MBH origin. Theorists have proposed various mechanisms for ejecting unbound stars, and these mechanisms can be tested with larger and more complete samples. HVSs' properties are linked to the nature and environment of the Milky Way's MBH, and, with future proper motion measurements, their trajectories may provide unique probes of the dark matter halo that surrounds the Milky Way.

  2. Low-background tracker development for SuperNEMO

    SciTech Connect

    Mott, James; Collaboration: SuperNEMO Collaboration; and others

    2013-08-08

    The SuperNEMO experiment will search for neutrinoless double beta decay (0νββ) with a target sensitivity of T{sub 1/2}(0ν) > 10{sup 26} years, corresponding to an effective neutrino mass of 50-100 meV. At its heart there is a low-background gaseous tracking detector which allows for extremely efficient background rejection and, if 0νββ is observed, may provide important insights into the mechanism via which it may be mediated. Radon inside the tracker, which can mimic rare ββ events, is one of the most dangerous backgrounds for SuperNEMO. To reach the target sensitivity the radon concentration inside the tracking volume must be < 0.15 mBq/m{sup 3}. To reach this challengingly-low level of radon, a considerable program of R and D has been undertaken. This includes automation of the tracker-wiring process, development of a dedicated setup to measure radon diffusion and a 'radon concentration line' which will be able to measure levels of radon in the μBq/m{sup 3} range.

  3. Embedded pitch adapters for the ATLAS Tracker Upgrade

    NASA Astrophysics Data System (ADS)

    Ullan, Miguel; Benitez, Victor; Pellegrini, Giulio; Fleta, Celeste; Lozano, Manuel; Lacasta, Carlos; Soldevila, Urmila; Garcia, Carmen

    2013-12-01

    In the current ATLAS tracker modules, sensor bonding pads are placed on their corresponding strips and oriented along the strips. This creates a difference in pitch and orientation between sensor bond pads and readout electronics bond pads. Therefore, a pitch adapter (PA), or “fan-in”, is needed. The purpose of these PA is the electrical interconnection of every channel from the detector bonding pads to the read-out chips, adapting the different pad pitch. Our new approach is to build those PAs inside the sensor; this is what we call Embedded Pitch Adapters. The idea is to use an additional metal layer in order to define a new group of pads, connected to the strips via tracks with the second metal. The embedded PAs have been fabricated on 4-in. prototype sensors for the ATLAS-Upgrade Endcap Tracker to test their performance and suitability. The tests confirm proper fabrication of the second metal tracks, and no effects on detector performance. No indication of cross-talk between first and second metal channels has been observed. A small indication of possible signal pick-up from the bulk has been observed in a few channels, which needs to be further investigated.

  4. Solar kinetics` photovoltaic concentrator module and tracker development

    SciTech Connect

    White, D.L.; Howell, B.

    1995-11-01

    Solar Kinetics, Inc., has been developing a point-focus concentrating photovoltaic module and tracker system under contract to Sandia National Laboratories. The primary focus of the contract was to achieve a module design that was manufacturable and passed Sandia`s environmental testing. Nine modules of two variations were assembled, tested, and characterized in Phase 1, and results of these tests were promising, with module efficiency approaching the theoretical limit achievable with the components used. The module efficiency was 11.9% at a solar irradiance of 850 W/sq m and an extrapolated cell temperature of 25 C. Improvements in module performance are anticipated as cell efficiencies meet their expectations. A 2-kW tracker and controller accommodating 20 modules was designed, built, installed, and operated at Solar Kinetics` test site. The drive used many commercially available components in an innovative arrangement to reduce cost and increase reliability. Backlash and bearing play were controlled by use of preloaded, low slip-stick, synthetic slide bearings. The controller design used a standard industrial programmable logic controller to perform ephemeris calculations, operate the actuators, and monitor encoders.

  5. An adaptive tracker for ShipIR/NTCS

    NASA Astrophysics Data System (ADS)

    Ramaswamy, Srinivasan; Vaitekunas, David A.

    2015-05-01

    A key component in any image-based tracking system is the adaptive tracking algorithm used to segment the image into potential targets, rank-and-select the best candidate target, and the gating of the selected target to further improve tracker performance. This paper will describe a new adaptive tracker algorithm added to the naval threat countermeasure simulator (NTCS) of the NATO-standard ship signature model (ShipIR). The new adaptive tracking algorithm is an optional feature used with any of the existing internal NTCS or user-defined seeker algorithms (e.g., binary centroid, intensity centroid, and threshold intensity centroid). The algorithm segments the detected pixels into clusters, and the smallest set of clusters that meet the detection criterion is obtained by using a knapsack algorithm to identify the set of clusters that should not be used. The rectangular area containing the chosen clusters defines an inner boundary, from which a weighted centroid is calculated as the aim-point. A track-gate is then positioned around the clusters, taking into account the rate of change of the bounding area and compensating for any gimbal displacement. A sequence of scenarios is used to test the new tracking algorithm on a generic unclassified DDG ShipIR model, with and without flares, and demonstrate how some of the key seeker signals are impacted by both the ship and flare intrinsic signatures.

  6. Tracker Performance Improvement Using Multiple-Sensor Data

    NASA Astrophysics Data System (ADS)

    Dayton, David C.; Asher, Kelly; Schneeberger, Timothy J.

    1989-09-01

    The increase in target signature information inherent in multi-spectral techniques can be used to increase tracker knowledge of current and predicted target states. In addition to the target location, the velocity, acceleration states, and target aspect angle, for example, can be measured. Aspect angle can be used to limit the possible future states of the target (aircraft, for example, have maximum maneuverability along an axis perpendicular to the wing plane.) Aspect angle, coupled with information concerning maximum target acceleration capabilities, can be used to provide an 'envelope' of possible future target locations. This envelope and position prediction are updated with each observation of the target status. A target pattern recognition algorithm has been used to classify target images, estimating both object identification and aspect angle. A modified form of the moments invariant technique, combined with a maximum likelihood classifier, has been developed and tested against imagery acquired with a laboratory image acquisition and analysis system. Simulations of combined motion and aspect angle sensing trackers indicated enhanced performance over systems with kinematic information only. A database of target imagery has been created, and algorithm accuracy as a function of signal-to-noise ratio has been determined. The effects of several pre-processing steps on the electro-optical sensor aspect angle measurement have also been studied. Critical invariance properties have been examined in a limited number of tests.

  7. Development of femtosecond optical frequency comb laser tracker

    NASA Astrophysics Data System (ADS)

    Yang, Ju-qing; Zhou, Wei-hu; Dong, Deng-feng; Zhang, Zi-li; Lao, Da-bao; Ji, Rong-yi; Wang, Da-yong

    2016-01-01

    A new type femtosecond laser tracker is one high precision measurement instrument with urgent need in science research region and industrial manufacture field. This paper focuses on the operational principle and the structure development of the femtosecond laser tracer, and the method of error compensation as well. The system modules were studied and constructed. The femtosecond frequency comb module was firstly analyzed and developed. The femtosecond laser frequency comb performed perfectly high precise distance measurement for laser tracker. The experimental result showed that the stability of repetition rate reached 3.0×10-12@1s and the stability of carrier envelop offset reached 1.0×10-10@1s. The initial experiment showed that measurement error was less than 1ppm. Later the error compensation module was introduced, and the optoelectronic aiming and tracking control module was built. The actual test result showed that the stability of miss distance was better than 2.0 μm, the tracking speed could reach 2m/s.

  8. Thermal performance of microinverters on dual-axis trackers

    NASA Astrophysics Data System (ADS)

    Hossain, Mohammad A.; Peshek, Timothy J.; Xu, Yifan; Ji, Liang; Sun, Jiayang; Abramson, Alexis; French, Roger H.

    2014-10-01

    Time-series insolation, environmental, thermal and power data were analyzed in a statistical analytical approach to identify the thermal performance of microinverters on dual-axis trackers under real-world operating conditions. This study analyzed 24 microinverters connected to 8 different brands of photovoltaic (PV) modules from July through October 2013 at the Solar Durability and Lifetime Extension (SDLE) SunFarm at Case Western Reserve University. Exploratory data analysis shows that the microinverter's temperature is strongly correlated with ambient temperature and PV module temperature, and moderately correlated with irradiance and AC power. Noontime data analysis reveals the variations of thermal behavior across different brands of PV module. Hierarchical clustering using the Euclidean distance measure principle was applied to noontime microinverter temperature data to group the similarly behaved microinverters. A multiple regression predictive model has been developed based on ambient temperature, PV module temperature, irradiance and AC power data to predict the microinverters temperature connected with different brands PV modules on dual-axis trackers.

  9. Electromagnetic tracker accuracy in the CyberKnife suite

    NASA Astrophysics Data System (ADS)

    Wilson, Emmanuel; Slack, Rebecca; Banovac, Filip; Dieterich, Sonja; Zhang, Hui; Cleary, Kevin

    2006-03-01

    Electromagnetic trackers have found inroads into medical applications as a tool for navigation in recent years. Their susceptibility to interference from both electromagnetic and ferromagnetic sources have prompted several accuracy assessment studies in past years. To the best of our knowledge, this is the first accuracy study conducted to characterize measurement accuracy of an NDI AURORA electromagnetic tracker within a CyberKnife radiosurgery suite. CyberKnife is a frameless, stereotactic radiosurgery device used to ablate tumors within the brain, spine and in recent years, the chest and abdomen. This paper uses a data collection protocol to collect uniformly distributed data points within a subset of the AURORA measurement volume in a CyberKnife suite. The key aim of the study is to determine the extent to which large metal components of the CyberKnife stereotactic radiosurgery device and robot mount contribute to overall system performance for the AURORA electromagnetic device. A secondary goal of the work is to determine the variation in accuracy and device behavior with the presence of ionizing radiation when the LINAC is turned on.

  10. Compact near-to-eye display with integrated gaze tracker

    NASA Astrophysics Data System (ADS)

    Järvenpää, Toni; Aaltonen, Viljakaisa

    2008-04-01

    Near-to-Eye Display (NED) offers a big screen experience to the user anywhere, anytime. It provides a way to perceive a larger image than the physical device itself is. Commercially available NEDs tend to be quite bulky and uncomfortable to wear. However, by using very thin plastic light guides with diffractive structures on the surfaces, many of the known deficiencies can be notably reduced. These Exit Pupil Expander (EPE) light guides enable a thin, light, user friendly and high performing see-through NED, which we have demonstrated. To be able to interact with the displayed UI efficiently, we have also integrated a video-based gaze tracker into the NED. The narrow light beam of an infrared light source is divided and expanded inside the same EPEs to produce wide collimated beams out from the EPE towards the eyes. Miniature video camera images the cornea and eye gaze direction is accurately calculated by locating the pupil and the glints of the infrared beams. After a simple and robust per-user calibration, the data from the highly integrated gaze tracker reflects the user focus point in the displayed image which can be used as an input device for the NED system. Realizable applications go from eye typing to playing games, and far beyond.

  11. Planar silicon sensors for the CMS tracker upgrade

    NASA Astrophysics Data System (ADS)

    Junkes, Alexandra

    2013-12-01

    The CMS tracker collaboration has initiated a large material investigation and irradiation campaign to identify the silicon material and design that fulfills all requirements for silicon tracking detectors for the high-luminosity phase of the Large Hadron Collider (HL-LHC). A variety of silicon p-in-n and n-in-p test-sensors made from Float Zone, Deep-Diffused FZ and Magnetic Czochralski materials were manufactured by one single industrial producer, thus guaranteeing similar conditions for the production and design of the test-structures. Properties of different silicon materials and design choices have been systematically studied and compared. The samples have been irradiated with neutrons (1 MeV) and protons (23 MeV and 23 GeV) corresponding to maximal fluences as expected for several positions of detector layers in the future tracker. Irradiations with protons of different energies have been performed to evaluate the energy dependence of the defect generation in oxygen rich material. All materials have been characterized before and after irradiations, and throughout an annealing treatment. The measurements performed on the structures include electrical sensor characterization, measurement of the collected charge injected with a beta source or laser light and bulk defect characterization. In this paper, a selection of results from the ongoing studies is presented.

  12. Radar interference blanking in radio astronomy using a Kalman tracker

    NASA Astrophysics Data System (ADS)

    Dong, W.; Jeffs, B. D.; Fisher, J. R.

    2005-06-01

    Radio astronomical observations of highly Doppler shifted spectral lines of neutral hydrogen and the hydroxyl molecule must often be made at frequencies allocated to pulsed air surveillance radar in the 1215-1350 MHz frequency range. The Green Bank telescope (GBT) and many other observatories must deal with these terrestrial signals. Even when strong radar fixed clutter echoes are removed, there are still weaker aircraft echoes present which can corrupt the data. We present an algorithm which improves aircraft echo blanking using a Kalman filter tracker to follow the path of a sequence of echoes observed on successive radar antenna sweeps. Aircraft tracks can be used to predict regions (in bearing and range) for the next expected echoes, even before they are detected. These data can then be blanked in real time without waiting for the pulse peak to arrive. Additionally, we briefly suggest an approach for a new Bayesian algorithm which combines tracker and pulse detector operations to enable more sensitive weak pulse detection. Examples are presented for Kalman tracking and radar transmission blanking using real observations at the GBT.

  13. Research and development of the laser tracker measurement system

    NASA Astrophysics Data System (ADS)

    Zhang, Z. L.; Zhou, W. H.; Lao, D. B.; Yuan, J.; Dong, D. F. F.; Ji, R. Y. Y.

    2013-01-01

    The working principle and system design of the laser tracker measurement system are introduced, as well as the key technologies and solutions in the implementation of the system. The design and implementation of the hardware and configuration of the software are mainly researched. The components of the hardware include distance measuring unit, angle measuring unit, tracking and servo control unit and electronic control unit. The distance measuring devices include the relative distance measuring device (IFM) and the absolute distance measuring device (ADM). The main component of the angle measuring device, the precision rotating stage, is mainly comprised of the precision axis and the encoders which are both set in the tracking head. The data processing unit, tracking and control unit and power supply unit are all set in the control box. The software module is comprised of the communication module, calibration and error compensation module, data analysis module, database management module, 3D display module and the man-machine interface module. The prototype of the laser tracker system has been accomplished and experiments have been carried out to verify the proposed strategies of the hardware and software modules. The experiments showed that the IFM distance measuring error is within 0.15mm, the ADM distance measuring error is within 3.5mm and the angle measuring error is within 3〞which demonstrates that the preliminary prototype can realize fundamental measurement tasks.

  14. Solar kinetics` photovoltaic concentrator module and tracker development

    SciTech Connect

    White, D.L.; Howell, B.

    1995-11-01

    Solar Kinetics, Inc., has been developing a point-focus concentrating photovoltaic module and tracker system under contract to Sandia National Laboratories. The primary focus of the contract was to achieve a module design that was manufacturable and passed Sandia`s environmental testing. Nine modules of two variations were assembled, tested, and characterized in Phase 1, and results of these tests were promising, with module efficiency approaching the theoretical limit achievable with the components used. The module efficiency was 11.9% at a solar irradiance of 850 W/m{sup 2} and an extrapolated cell temperature of 25{degrees}C. Improvements in module performance are anticipated as cell efficiencies meet their expectations. A 2-kW tracker and controller accommodating 20 modules was designed, built, installed, and operated at Solar Kinetics` test site. The drive used many commercially available components in an innovative arrangement to reduce cost and increase reliability. Backlash and bearing play were controlled by use of preloaded, low slip-stick, synthetic slide bearings. The controller design used a standard industrial programmable logic controller to perform ephemeris calculations, operate the actuators, and monitor encoders.

  15. STARS no star on Kauai

    SciTech Connect

    Jones, M.

    1993-04-01

    The island of Kuai, home to the Pacific Missile Range Facility, is preparing for the first of a series of Star Wars rocket launches expected to begin early this year. The Strategic Defense Initiative plans 40 launches of the Stategic Target System (STARS) over a 10-year period. The focus of the tests appears to be weapons and sensors designed to combat multiple-warhead ICBMs, which will be banned under the START II Treaty that was signed in January. The focus of this article is to express the dubious value of testing the STARS at a time when their application will not be an anticipated problem.

  16. A Robust Compositional Architecture for Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Brat, Guillaume; Deney, Ewen; Farrell, Kimberley; Giannakopoulos, Dimitra; Jonsson, Ari; Frank, Jeremy; Bobby, Mark; Carpenter, Todd; Estlin, Tara

    2006-01-01

    Space exploration applications can benefit greatly from autonomous systems. Great distances, limited communications and high costs make direct operations impossible while mandating operations reliability and efficiency beyond what traditional commanding can provide. Autonomous systems can improve reliability and enhance spacecraft capability significantly. However, there is reluctance to utilizing autonomous systems. In part this is due to general hesitation about new technologies, but a more tangible concern is that of reliability of predictability of autonomous software. In this paper, we describe ongoing work aimed at increasing robustness and predictability of autonomous software, with the ultimate goal of building trust in such systems. The work combines state-of-the-art technologies and capabilities in autonomous systems with advanced validation and synthesis techniques. The focus of this paper is on the autonomous system architecture that has been defined, and on how it enables the application of validation techniques for resulting autonomous systems.

  17. Low-cost multi-terrain autonomous vehicle for hostile environments

    SciTech Connect

    Perez, M. L., LLNL

    1996-12-03

    This paper describes an innovative and unique autonomous vehicle being developed at the Lawrence Livermore National Laboratory (LLNL) for versatile use in hostile environments. Conventional vehicles used in decommissioning and decontaminating, police activity, and unmanned military operations typically are designed with four-wheels or track in contact with the environment. Although four-wheel and track vehicles work well, they are limited in negotiating saturated terrain, steep hills and soft soils. The Spiral Track Autonomous Robot (STAR) is a versatile and maneuverable multi-terrain mobile vehicle that uses the latest available computer technology and two Archimedes screws, in contact with the local environment to intelligently negotiate a hostile environment.

  18. The Functioning of Autonomous Colleges

    ERIC Educational Resources Information Center

    Rao, V. Pala Prasada; Rao, Digumarti Bhaskara

    2012-01-01

    The college gets separated from the university, though not completely, when it is an autonomous college, which is practice in India. Academic package will become flexible and the decision-making is internalized, changes and updating could be easily carried out, depending on the need as reflected from the feedback taken from alumni, user sectors,…

  19. Computing architecture for autonomous microgrids

    SciTech Connect

    Goldsmith, Steven Y.

    2015-09-29

    A computing architecture that facilitates autonomously controlling operations of a microgrid is described herein. A microgrid network includes numerous computing devices that execute intelligent agents, each of which is assigned to a particular entity (load, source, storage device, or switch) in the microgrid. The intelligent agents can execute in accordance with predefined protocols to collectively perform computations that facilitate uninterrupted control of the .

  20. AARD - Autonomous Airborne Refueling Demonstration

    NASA Technical Reports Server (NTRS)

    Ewers, Dick

    2007-01-01

    This viewgraph document reviews the Autonomous Airborne Refueling Demonstration program, and NASA Dryden's work in the program. The primary goal of the program is to make one fully automatic probe-to-drogue engagement using the AARD system. There are pictures of the aircraft approaching to the docking.

  1. An Autonomous Spacecraft Agent Prototype

    NASA Technical Reports Server (NTRS)

    Pell, Barney; Bernard, Douglas E.; Chien, Steve A.; Gat, Erann; Muscettola, Nicola; Nayak, P. Pandurang; Wagner, Michael D.; Williams, Brian C.

    1997-01-01

    This paper describes the New Millennium Remote Agent (NMRA) architecture for autonomous spacecraft control systems. This architecture integrates traditional real-time monitoring and control with constraint-based planning and scheduling, robust multi-threaded execution, and model-based diagnosis and reconfiguration.

  2. Ka-Band Autonomous Formation Flying Sensor

    NASA Technical Reports Server (NTRS)

    Tien, Jeffrey; Purcell, George, Jr.; Srinivasan, Jeffrey; Ciminera, Michael; Srinivasan, Meera; Meehan, Thomas; Young, Lawrence; Aung, MiMi; Amaro, Luis; Chong, Yong; Quirk, Kevin

    2004-01-01

    Ka-band integrated range and bearing-angle formation sensor called the Autonomous Formation Flying (AFF) Sensor has been developed to enable deep-space formation flying of multiple spacecraft. The AFF Sensor concept is similar to that of the Global Positioning System (GPS), but the AFF Sensor would not use the GPS. The AFF Sensor would reside in radio transceivers and signal-processing subsystems aboard the formation-flying spacecraft. A version of the AFF Sensor has been developed for initial application to the two-spacecraft StarLight optical-interferometry mission, and several design investigations have been performed. From the prototype development, it has been concluded that the AFF Sensor can be expected to measure distances and directions with standard deviations of 2 cm and 1 arc minute, respectively, for spacecraft separations ranging up to about 1 km. It has also been concluded that it is necessary to optimize performance of the overall mission through design trade-offs among the performance of the AFF Sensor, the field of view of the AFF Sensor, the designs of the spacecraft and the scientific instruments that they will carry, the spacecraft maneuvers required for formation flying, and the design of a formation-control system.

  3. The Emerging Infrastructure of Autonomous Astronomy

    NASA Astrophysics Data System (ADS)

    Seaman, R.; Allan, A.; Axelrod, T.; Cook, K.; White, R.; Williams, R.

    2007-10-01

    Advances in the understanding of cosmic processes demand that sky transient events be confronted with statistical techniques honed on static phenomena. Time domain data sets require vast surveys such as LSST {http://www.lsst.org/lsst_home.shtml} and Pan-STARRS {http://www.pan-starrs.ifa.hawaii.edu}. A new autonomous infrastructure must close the loop from the scheduling of survey observations, through data archiving and pipeline processing, to the publication of transient event alerts and automated follow-up, and to the easy analysis of resulting data. The IVOA VOEvent {http://voevent.org} working group leads efforts to characterize sky transient alerts published through VOEventNet {http://voeventnet.org}. The Heterogeneous Telescope Networks (HTN {http://www.telescope-networks.org}) consortium are observatories and robotic telescope projects seeking interoperability with a long-term goal of creating an e-market for telescope time. Two projects relying on VOEvent and HTN are eSTAR {http://www.estar.org.uk} and the Thinking Telescope {http://www.thinkingtelescopes.lanl.gov} Project.

  4. Networks for Autonomous Formation Flying Satellite Systems

    NASA Technical Reports Server (NTRS)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  5. 2D/3D Visual Tracker for Rover Mast

    NASA Technical Reports Server (NTRS)

    Bajracharya, Max; Madison, Richard W.; Nesnas, Issa A.; Bandari, Esfandiar; Kunz, Clayton; Deans, Matt; Bualat, Maria

    2006-01-01

    A visual-tracker computer program controls an articulated mast on a Mars rover to keep a designated feature (a target) in view while the rover drives toward the target, avoiding obstacles. Several prior visual-tracker programs have been tested on rover platforms; most require very small and well-estimated motion between consecutive image frames a requirement that is not realistic for a rover on rough terrain. The present visual-tracker program is designed to handle large image motions that lead to significant changes in feature geometry and photometry between frames. When a point is selected in one of the images acquired from stereoscopic cameras on the mast, a stereo triangulation algorithm computes a three-dimensional (3D) location for the target. As the rover moves, its body-mounted cameras feed images to a visual-odometry algorithm, which tracks two-dimensional (2D) corner features and computes their old and new 3D locations. The algorithm rejects points, the 3D motions of which are inconsistent with a rigid-world constraint, and then computes the apparent change in the rover pose (i.e., translation and rotation). The mast pan and tilt angles needed to keep the target centered in the field-of-view of the cameras (thereby minimizing the area over which the 2D-tracking algorithm must operate) are computed from the estimated change in the rover pose, the 3D position of the target feature, and a model of kinematics of the mast. If the motion between the consecutive frames is still large (i.e., 3D tracking was unsuccessful), an adaptive view-based matching technique is applied to the new image. This technique uses correlation-based template matching, in which a feature template is scaled by the ratio between the depth in the original template and the depth of pixels in the new image. This is repeated over the entire search window and the best correlation results indicate the appropriate match. The program could be a core for building application programs for systems

  6. Design of an upgraded D0 silicon microstrip tracker for Run IIb at the Tevatron

    SciTech Connect

    Hanagaki, K.; /Fermilab

    2004-01-01

    The D0 collaboration planned to upgrade the Silicon Tracker to withstand the radiation dose corresponding to above 2 fb{sup -1} of data. This new detector was designed to be functional up to at least 15 fb{sup -1}. The authors report on the design of the new Silicon Tracker with details of the innermost layer.

  7. Lightweight dual-axis tracker designs for dish-based HCPV

    NASA Astrophysics Data System (ADS)

    Angel, Roger; Cuerden, Brian; Whiteside, Andy

    2014-09-01

    Dish-based HCPV holds the promise of solar electricity at lower cost than for flat panel PV, provided that the dual-axis tracker cost can be minimized. Here we outline first and second generation lightweight tracker designs that include supports for a rectangular array of square dish mirrors and receivers located at their foci.

  8. Symbiotic stars

    NASA Technical Reports Server (NTRS)

    Kafatos, M.; Michalitsianos, A. G.

    1984-01-01

    The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

  9. Experiment D005: Star occultation navigation

    NASA Technical Reports Server (NTRS)

    Silva, R. M.; Jorris, T. R.; Vallerie, E. M., III

    1971-01-01

    The usefulness of star occultation measurements for space navigation and the determination of a horizon density profile which could be used to update atmospheric models for horizon-based measurement systems were studied. The time of occultation of a known star by a celestial body, as seen by an orbiting observer, determines a cylinder of position, the axis of which is the line through the star and the body center, and the radius of which is equal to the occulting-body radius. The dimming percentage, with respect to the altitude of this grazing ray from the star to the observer, is a percentage altitude for occultation. That is, the star can be assumed to be occulted when it reaches a predetermined percentage of its unattenuated value. The procedure used was to measure this attenuation with respect to time to determine the usefulness of the measurements for autonomous space navigation. In this experiment, the crewmembers had to accomplish star acquisition, identification, calibration, and tracking. Instrumentation was required only for measurement of the relative intensity of the star as it set into the atmosphere.

  10. Autonomic Computing: Freedom or a Threat?

    SciTech Connect

    Fink, Glenn A.; Frincke, Deb

    2007-12-01

    No longer is the question whether autonomic computing will gain general acceptance but when. Experts expect autonomic computing to be widely used within 10 years. When it does become mainstream, how will autonomics change system administration and corporations, and will the change be for better or worse? The answer depends on how well we anticipate the limitations of what autonomic systems are suited to do, whether we can collectively address the vulnerabilities of autonomic approaches as we draw upon the advantages, and whether administrators, companies, partners, and users are prepared for the transition. This article presents some design considerations to address the first two issues and some suggested survival techniques for the third.

  11. Two-axis tracker for solar panels and the like

    SciTech Connect

    Liao, Henry H.

    2013-04-16

    A tracker including an outer post having elongated bore and a lower end mounted on a sub-structure, an inner pole rotatably received in the elongated bore, a lower bearing in the bore adjacent a lower end of the outer post and attached thereto to be constrained from lateral movement and mounted on the sub-structure such that a lower end of the inner pole rests on and is supported by the lower bearing, an upper bearing near an upper end of the outer post, a circumferential drive supported on the outer post for rotating the inner pole relative to the outer post, such that substantially a full weight of a load on the inner pole is directly transmitted to the sub-structure and lateral force and torque leverage are placed on a full length of the outer post by way of the upper and lower bearing.

  12. Performance of the CLAS12 Silicon Vertex Tracker modules

    SciTech Connect

    Antonioli, Mary Ann; Boiarinov, Serguie; Bonneau, Peter R.; Elouadrhiri, Latifa; Eng, Brian J.; Gotra, Yuri N.; Kurbatov, Evgeny O.; Leffel, Mindy A.; Mandal, Saptarshi; McMullen, Marc E.; Merkin, Mikhail M.; Raydo, Benjamin J.; Teachey, Robert W,; Tucker, Ross J.; Ungaro, Maurizio; Yegneswaran, Amrit S.; Ziegler, Veronique

    2013-12-01

    For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156{micro}m, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.

  13. DAMPE silicon tracker on-board data compression algorithm

    NASA Astrophysics Data System (ADS)

    Dong, Yi-Fan; Zhang, Fei; Qiao, Rui; Peng, Wen-Xi; Fan, Rui-Rui; Gong, Ke; Wu, Di; Wang, Huan-Yu

    2015-11-01

    The Dark Matter Particle Explorer (DAMPE) is an upcoming scientific satellite mission for high energy gamma-ray, electron and cosmic ray detection. The silicon tracker (STK) is a subdetector of the DAMPE payload. It has excellent position resolution (readout pitch of 242 μm), and measures the incident direction of particles as well as charge. The STK consists of 12 layers of Silicon Micro-strip Detector (SMD), equivalent to a total silicon area of 6.5 m2. The total number of readout channels of the STK is 73728, which leads to a huge amount of raw data to be processed. In this paper, we focus on the on-board data compression algorithm and procedure in the STK, and show the results of initial verification by cosmic-ray measurements. Supported by Strategic Priority Research Program on Space Science of Chinese Academy of Sciences (XDA040402) and National Natural Science Foundation of China (1111403027)

  14. Performance of the CLAS12 Silicon Vertex Tracker modules

    NASA Astrophysics Data System (ADS)

    Antonioli, M. A.; Boiarinov, S.; Bonneau, P.; Elouadrhiri, L.; Eng, B.; Gotra, Y.; Kurbatov, E.; Leffel, M.; Mandal, S.; McMullen, M.; Merkin, M.; Raydo, B.; Teachey, W.; Tucker, R.; Ungaro, M.; Yegneswaran, A.; Ziegler, V.

    2013-12-01

    For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156 μm, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.

  15. Design and Performance of the Keck Angle Tracker

    NASA Technical Reports Server (NTRS)

    Crawford, Samuel L.; Ragland, S.; Booth, A.; Colavita, M. M.; Hovland, E.

    2006-01-01

    The Keck Angle Tracker (KAT) is a key subsystem in the NASA-funded Keck Interferometer at the Keck Observatory on the summit of Mauna Kea in Hawaii. KAT, which has been in operation since the achievement of first fringes in March 2001, senses the tilt of the stellar wavefront for each of the beams from the interferometer telescopes and provides tilt error signals to fast tip/tilt mirrors for high-bandwidth, wavefront tilt correction. In addition, KAT passes low-bandwidth, desaturation offsets to the adaptive optics system of the Keck telescopes to correct for slow pointing drifts. We present an overview of the instrument design and recent performance of KAT in support of the V2 science and nulling observing modes of the Keck Interferometer.

  16. Echo tracker/range finder for radars and sonars

    NASA Technical Reports Server (NTRS)

    Constantinides, N. J. (Inventor)

    1982-01-01

    An echo tracker/range finder or altimeter is described. The pulse repetition frequency (PFR) of a predetermined plurality of transmitted pulses is adjusted so that echo pulses received from a reflecting object are positioned between transmitted pulses and divided their interpulse time interval into two time intervals having a predetermined ratio with respect to each other. The invention described provides a means whereby the arrival time of a plurality of echo pulses is defined as the time at which a composite echo pulse formed of a sum of the individual echo pulses has the highest amplitude. The invention is applicable to radar systems, sonar systems, or any other kind of system in which pulses are transmitted and echoes received therefrom.

  17. Standard metrics for a plug-and-play tracker

    NASA Astrophysics Data System (ADS)

    Antonisse, Jim; Young, Darrell

    2012-06-01

    The Motion Imagery Standards Board (MISB) has previously established a metadata "micro-architecture" for standards-based tracking. The intent of this work is to facilitate both the collaborative development of competent tracking systems, and the potentially distributed and dispersed execution of tracker system components in real-world execution environments. The approach standardizes a set of five quasi-sequential modules in image-based tracking. However, in order to make the plug-and-play architecture truly useful we need metrics associated with each module (so that, for instance, a researcher who "plugs in" a new component can ascertain whether he/she did better or worse with the component). This paper proposes the choice of a new, unifying set of metrics based on an informationtheoretic approach to tracking, which the MISB is nominating as DoD/IC/NATO standards.

  18. Tail Catcher Muon Tracker For The CALICE Test Beam

    SciTech Connect

    Dyshkant, Alexander

    2006-10-27

    Results on the construction and commissioning of the CALICE Tail-catcher/Muon Tracker (TCMT) are presented. The {approx}1 m3 prototype uses extruded scintillating strips mated to silicon-photomultipliers and is located behind the CALICE hadron calorimeter. The TCMT will provide a snapshot of the tail end of hadron showers, which is crucial to the validation of hadronic Monte Carlo. It will also serve as a prototype muon system for any Linear Collider Detector (ILC) and will facilitate studies of muon tracking and identification within the particle flow reconstruction framework. Additionally, the TCMT will provide valuable practical experience with hadronic leakage and punch-through from thin calorimeters, as are envisaged for the ILC detector, and the impact of the coil in correcting for this leakage.

  19. The Tevatron tune tracker pll - theory, implementation and measurements

    SciTech Connect

    Tan, Cheng-Yang; /Fermilab

    2004-12-01

    The Tevatron tune tracker is based on the idea that the transverse phase response of the beam can be measured quickly and accurately enough to allow us to track the betatron tune with a phase locked loop (PLL). The goal of this paper is to show the progress of the PLL project at Fermilab. We will divide this paper into three parts: theory, implementation and measurements. In the theory section, we will use a simple linear model to show that our design will track the betatron tune under conditions that occur in the Tevatron. In the implementation section we will break down and examine each part of the PLL and in some cases calculate the actual PLL parameters used in our system from beam measurements. And finally in the measurements section we will show the results of the PLL performance.

  20. Higher throughput high resolution multi-worm tracker

    NASA Astrophysics Data System (ADS)

    Javer, Avelino; Li, Kezhi; Gyenes, Bertalan; Brown, Andre; Behavioural Genomics Team

    2015-03-01

    We have developed a high throughput imaging system for tracking multiple nematode worms at high resolution. The tracker consists of 6 cameras mounted on a motorized gantry so that up to 48 plates (each with approximately 30 worms) can be imaged without user intervention. To deal with the high data rate of the cameras we use real time processing to find worms and only save the immediately surrounding pixels. The system is also equipped with automatic oxygen and carbon dioxide control for observing stimulus response behaviour. We will describe the design and performance of the new system, some of the challenges of truly high throughput behaviour recording, and report preliminary results on inter-individual variation in behaviour as well as a quantitative analysis of C. elegans response to hypoxia, oxygen reperfusion, and carbon dioxide. Funding provided by the Medical Research Council.

  1. Circumnutation Tracker: novel software for investigation of circumnutation

    PubMed Central

    2014-01-01

    Background An endogenous, helical plant organ movement named circumnutation is ubiquitous in the plant kingdom. Plant shoots, stems, tendrils, leaves, and roots commonly circumnutate but their appearance is still poorly described. To support such investigations, novel software Circumnutation Tracker (CT) for spatial-temporal analysis of circumnutation has been developed. Results CT works on time-lapse video and collected circumnutation parameters: period, length, rate, shape, angle, and clockwise- and counterclockwise directions. The CT combines a filtering algorithm with a graph-based method to describe the parameters of circumnutation. The parameters of circumnutation of Helianthus annuus hypocotyls and the relationship between cotyledon arrangement and circumnutation geometry are presented here to demonstrate the CT options. Conclusions We have established that CT facilitates and accelerates analysis of circumnutation. In combination with the physiological, molecular, and genetic methods, this software may be a powerful tool also for investigations of gravitropism, biological clock, and membrane transport, i.e. processes involved in the mechanism of circumnutation.

  2. Articulated Arm Coordinate Measuring Machine Calibration by Laser Tracker Multilateration

    PubMed Central

    Majarena, Ana C.; Brau, Agustín; Velázquez, Jesús

    2014-01-01

    A new procedure for the calibration of an articulated arm coordinate measuring machine (AACMM) is presented in this paper. First, a self-calibration algorithm of four laser trackers (LTs) is developed. The spatial localization of a retroreflector target, placed in different positions within the workspace, is determined by means of a geometric multilateration system constructed from the four LTs. Next, a nonlinear optimization algorithm for the identification procedure of the AACMM is explained. An objective function based on Euclidean distances and standard deviations is developed. This function is obtained from the captured nominal data (given by the LTs used as a gauge instrument) and the data obtained by the AACMM and compares the measured and calculated coordinates of the target to obtain the identified model parameters that minimize this difference. Finally, results show that the procedure presented, using the measurements of the LTs as a gauge instrument, is very effective by improving the AACMM precision. PMID:24688418

  3. Articulated arm coordinate measuring machine calibration by laser tracker multilateration.

    PubMed

    Santolaria, Jorge; Majarena, Ana C; Samper, David; Brau, Agustín; Velázquez, Jesús

    2014-01-01

    A new procedure for the calibration of an articulated arm coordinate measuring machine (AACMM) is presented in this paper. First, a self-calibration algorithm of four laser trackers (LTs) is developed. The spatial localization of a retroreflector target, placed in different positions within the workspace, is determined by means of a geometric multilateration system constructed from the four LTs. Next, a nonlinear optimization algorithm for the identification procedure of the AACMM is explained. An objective function based on Euclidean distances and standard deviations is developed. This function is obtained from the captured nominal data (given by the LTs used as a gauge instrument) and the data obtained by the AACMM and compares the measured and calculated coordinates of the target to obtain the identified model parameters that minimize this difference. Finally, results show that the procedure presented, using the measurements of the LTs as a gauge instrument, is very effective by improving the AACMM precision. PMID:24688418

  4. Autonomous Cryogenics Loading Operations Simulation Software: Knowledgebase Autonomous Test Engineer

    NASA Technical Reports Server (NTRS)

    Wehner, Walter S.

    2012-01-01

    The Simulation Software, KATE (Knowledgebase Autonomous Test Engineer), is used to demonstrate the automatic identification of faults in a system. The ACLO (Autonomous Cryogenics Loading Operation) project uses KATE to monitor and find faults in the loading of the cryogenics int o a vehicle fuel tank. The KATE software interfaces with the IHM (Integrated Health Management) systems bus to communicate with other systems that are part of ACLO. One system that KATE uses the IHM bus to communicate with is AIS (Advanced Inspection System). KATE will send messages to AIS when there is a detected anomaly. These messages include visual inspection of specific valves, pressure gauges and control messages to have AIS open or close manual valves. My goals include implementing the connection to the IHM bus within KATE and for the AIS project. I will also be working on implementing changes to KATE's Ul and implementing the physics objects in KATE that will model portions of the cryogenics loading operation.

  5. Autonomous Cryogenics Loading Operations Simulation Software: Knowledgebase Autonomous Test Engineer

    NASA Technical Reports Server (NTRS)

    Wehner, Walter S., Jr.

    2013-01-01

    Working on the ACLO (Autonomous Cryogenics Loading Operations) project I have had the opportunity to add functionality to the physics simulation software known as KATE (Knowledgebase Autonomous Test Engineer), create a new application allowing WYSIWYG (what-you-see-is-what-you-get) creation of KATE schematic files and begin a preliminary design and implementation of a new subsystem that will provide vision services on the IHM (Integrated Health Management) bus. The functionality I added to KATE over the past few months includes a dynamic visual representation of the fluid height in a pipe based on number of gallons of fluid in the pipe and implementing the IHM bus connection within KATE. I also fixed a broken feature in the system called the Browser Display, implemented many bug fixes and made changes to the GUI (Graphical User Interface).

  6. Alignment of the CMS silicon strip tracker during stand-alone commissioning

    SciTech Connect

    Adam, W.; et al.

    2009-07-01

    The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

  7. Silicon photomultiplier choice for the scintillating fibre tracker in second generation proton computed tomography scanner

    SciTech Connect

    Gearhart, A.; Johnson, E.; Medvedev, V.; Ronzhin, A.; Rykalin, V.; Rubinov, P.; Sleptcov, V.; /Unlisted, RU

    2012-03-01

    Scintillating fibers are capable of charged particle tracking with high position resolution, as demonstrated by the central fiber tracker of the D0 experiment. The charged particles will deposit less energy in the polystyrene scintillating fibers as opposed to a typical silicon tracker of the same thickness, while SiPM's are highly efficient at detecting photons created by the passage of the charged particle through the fibers. The current prototype of the Proton Computed Tomography (pCT) tracker uses groups of three 0.5 mm green polystyrene based scintillating fibers connected to a single SiPM, while first generation prototype tracker used Silicon strip detectors. The results of R&D for the Scintillating Fiber Tracker (SFT) as part of the pCT detector are outlined, and the premise for the selection of SiPM is discussed.

  8. Laser Tracker Calibration - Testing the Angle Measurement System -

    SciTech Connect

    Gassner, Georg; Ruland, Robert; /SLAC

    2008-12-05

    Physics experiments at the SLAC National Accelerator Laboratory (SLAC) usually require high accuracy positioning, e. g. 100 {micro}m over a distance of 150 m or 25 {micro}m in a 10 x 10 x 3 meter volume. Laser tracker measurement systems have become one of the most important tools for achieving these accuracies when mapping components. The accuracy of these measurements is related to the manufacturing tolerances of various individual components, the resolutions of measurement systems, the overall precision of the assembly, and how well imperfections can be modeled. As with theodolites and total stations, one can remove the effects of most assembly and calibration errors by measuring targets in both direct and reverse positions and computing the mean to obtain the result. However, this approach does not compensate for errors originating from the encoder system. In order to improve and gain a better understanding of laser tracker angle measurement tolerances we extended our laboratory's capabilities with the addition of a horizontal angle calibration test stand. This setup is based on the use of a high precision rotary table providing an angular accuracy of better than 0.2 arcsec. Presently, our setup permits only tests of the horizontal angle measurement system. A test stand for vertical angle calibration is under construction. Distance measurements (LECOCQ & FUSS, 2000) are compared to an interferometer bench for distances of up to 32 m. Together both tests provide a better understanding of the instrument and how it should be operated. The observations also provide a reasonable estimate of covariance information of the measurements according to their actual performance for network adjustments.

  9. Construction and testing of the scintillating fibre trackers for MICE

    SciTech Connect

    Fish, Aron

    2009-09-01

    The discovery of neutrino mass through experimental evidence of neutrino oscillations at the end of the last century has provided the first proof that the Standard Model of particle physics is incomplete. To be able to extend the Standard Model to incorporate massive neutrinos first requires many theoretical uncertainties surrounding the particle and its interactions to be understood. Therefore, a dedicated experimental programme is needed over the coming decades to provide precision measurements of the neutrino oscillation parameters and also a possible measurement of CP violation in the lepton sector, which could have astrophysical consequences. An intense source of neutrinos is required to achieve these precision measurements and the leading contender proposed to provide this neutrino beam, is the Neutrino Factory. Before a Neutrino Factory facility can be realised, a number of technological challenges need to be evaluated and understood first. One of which, is reduce the large phase space volume (emittance) of the initial muon beam, which is eventually stored and through decay provides the neutrino beam. Ionisation cooling is the chosen method to achieve this and the Muon Ionisation Cooling Experiment (MICE) at Rutherford Laboratory in the UK, is required to demonstrate ionisation cooling and its feasibility for a Neutrino Factory. To demonstrate ionisation cooling, a section of a cooling channel will be constructed and single-particle measurements of emittance of a muon beam before and after the cooling channel from particle spectrometers will be compared. To measure emittance accurately requires precision measurements of the momenta and spatial coordinates at the spectrometers by tracking devices in a uniform magnetic field. The focus of this thesis is based around the construction and testing of the MICE tracker(s), including a study of its simulated performance and also construction and testing of a prototype.

  10. The alcohol tracker application: an initial evaluation of user preferences

    PubMed Central

    Zhang, Melvyn W B; Ward, John; Ying, John J B; Pan, Fang; Ho, Roger C M

    2016-01-01

    Background The prevalence of at-risk drinking and alcohol use disorders is increasing. Advances in technology have resulted in numerous smartphone applications for this disorder. However, there are still concerns about the evidence base of previously developed alcohol applications. Objective The following study aims to illustrate how the authors have made use of innovative methodologies to overcome the issues relating to the accuracy of tracking the amount of alcohol one has consumed; it also aims to determine user perceptions about the innovative tracker and various other features of an alcohol self-management application among a group of individuals from the general population of a developed country (Canada). Methodology A native alcohol self-management application was developed. In order to determine user perspectives towards this new innovative application, the authors took advantage and made use of crowdsourcing to acquire user perspectives. Results Our results showed that smartphone ownership is highest among the age group of 35–44 years (91%) and lowest for those aged between 55 and 64 (58%). Our analysis also showed that 25–34-year-olds and 35–44-year-olds drink more frequently than the other groups. Results suggest that notification and information were the two most useful functions, with psychotherapy expected to be the least useful. Females indicated that notification service was the most useful function, while males preferred the information component. Conclusions This study has demonstrated how the authors have made use of innovative technologies to overcome the existing concerns pertaining to the utilisation of the blood alcohol concentration levels as a tracker. In addition, the authors have managed to highlight user preferences with regard to an alcohol application. PMID:27019744

  11. Morphologic Changes in Autonomic Nerves in Diabetic Autonomic Neuropathy.

    PubMed

    Jin, Heung Yong; Baek, Hong Sun; Park, Tae Sun

    2015-12-01

    Diabetic neuropathy is one of the major complications of diabetes, and it increases morbidity and mortality in patients with both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Because the autonomic nervous system, for example, parasympathetic axons, has a diffuse and wide distribution, we do not know the morphological changes that occur in autonomic neural control and their exact mechanisms in diabetic patients with diabetic autonomic neuropathy (DAN). Although the prevalence of sympathetic and parasympathetic neuropathy is similar in T1DM versus T2DM patients, sympathetic nerve function correlates with parasympathetic neuropathy only in T1DM patients. The explanation for these discrepancies might be that parasympathetic nerve function was more severely affected among T2DM patients. As parasympathetic nerve damage seems to be more advanced than sympathetic nerve damage, it might be that parasympathetic neuropathy precedes sympathetic neuropathy in T2DM, which was Ewing's concept. This could be explained by the intrinsic morphologic difference. Therefore, the morphological changes in the sympathetic and parasympathetic nerves of involved organs in T1DM and T2DM patients who have DAN should be evaluated. In this review, evaluation methods for morphological changes in the epidermal nerves of skin, and the intrinsic nerves of the stomach will be discussed. PMID:26706915

  12. Chameleon stars

    SciTech Connect

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Singleton, Douglas

    2011-10-15

    We consider a gravitating spherically symmetric configuration consisting of a scalar field nonminimally coupled to ordinary matter in the form of a perfect fluid. For this system we find static, regular, asymptotically flat solutions for both relativistic and nonrelativistic cases. It is shown that the presence of the nonminimal interaction leads to substantial changes both in the radial matter distribution of the star and in the star's total mass. A simple stability test indicates that, for the choice of parameters used in the paper, the solutions are unstable.

  13. The friendly stars

    NASA Astrophysics Data System (ADS)

    Martin, Martha Evans

    Describes prominent stars such as Vega, Arcturus, and Antares and means of identifying them, discusses the constellations in which they are located, and explains star names, stellar light, distances between stars, and types of stars.

  14. Beam-based measurement of the center of the new STAR pipe

    SciTech Connect

    Robert-Demolaize, G.

    2014-02-25

    During the RHIC Shutdown preceding Run13 for polarized protons, various upgrades were brought to the STAR detector, one of which being the partial installation of the Forward GEM Tracker (FGT). This installation includes a new beam pipe at the center of the detector with an internal radius half the size of what the replaced pipe was, from 40 mm to 20 mm. The following reviews the results of a vertical aperture scans in the STAR interaction region performed at injection energy with both beams, and gives an estimate of the measured transverse offset of the new STAR pipe.

  15. An Autonomously Reciprocating Transmembrane Nanoactuator.

    PubMed

    Watson, Matthew A; Cockroft, Scott L

    2016-01-22

    Biological molecular machines operate far from equilibrium by coupling chemical potential to repeated cycles of dissipative nanomechanical motion. This principle has been exploited in supramolecular systems that exhibit true machine behavior in solution and on surfaces. However, designed membrane-spanning assemblies developed to date have been limited to simple switches or stochastic shuttles, and true machine behavior has remained elusive. Herein, we present a transmembrane nanoactuator that turns over chemical fuel to drive autonomous reciprocating (back-and-forth) nanomechanical motion. Ratcheted reciprocating motion of a DNA/PEG copolymer threaded through a single α-hemolysin pore was induced by a combination of DNA strand displacement processes and enzyme-catalyzed reactions. Ion-current recordings revealed saw-tooth patterns, indicating that the assemblies operated in autonomous, asymmetric cycles of conformational change at rates of up to one cycle per minute. PMID:26661295

  16. Autonomous spacecraft maintenance study group

    NASA Technical Reports Server (NTRS)

    Marshall, M. H.; Low, G. D.

    1981-01-01

    A plan to incorporate autonomous spacecraft maintenance (ASM) capabilities into Air Force spacecraft by 1989 is outlined. It includes the successful operation of the spacecraft without ground operator intervention for extended periods of time. Mechanisms, along with a fault tolerant data processing system (including a nonvolatile backup memory) and an autonomous navigation capability, are needed to replace the routine servicing that is presently performed by the ground system. The state of the art fault handling capabilities of various spacecraft and computers are described, and a set conceptual design requirements needed to achieve ASM is established. Implementations for near term technology development needed for an ASM proof of concept demonstration by 1985, and a research agenda addressing long range academic research for an advanced ASM system for 1990s are established.

  17. Treatment of gastrointestinal autonomic neuropathy.

    PubMed

    Törnblom, Hans

    2016-03-01

    The symptoms caused by gastrointestinal autonomic neuropathy in diabetes mellitus is important to highlight since it affects a large proportion of people with diabetes, regardless of whether this is type 1 or type 2. Gastroparesis and general signs of bowel dysfunction, such as constipation, diarrhoea and abdominal pain are most often encountered and involve both pharmacological and non-pharmacological treatment options. This mini-review summarises a presentation given at the 'Diagnosis and treatment of autonomic diabetic neuropathy in the gut' symposium at the 2015 annual meeting of the EASD. It is accompanied by another mini-review on a topic from this symposium (by Azpiroz and Malagelada, DOI: 10.1007/s00125-015-3831-1 ) and a commentary by the Session Chair, Péter Kempler (DOI: 10.1007/s00125-015-3826-y ). PMID:26634570

  18. Experiments on autonomous Boolean networks

    NASA Astrophysics Data System (ADS)

    Rosin, David P.; Rontani, Damien; Gauthier, Daniel J.; Schöll, Eckehard

    2013-06-01

    We realize autonomous Boolean networks by using logic gates in their autonomous mode of operation on a field-programmable gate array. This allows us to implement time-continuous systems with complex dynamical behaviors that can be conveniently interconnected into large-scale networks with flexible topologies that consist of time-delay links and a large number of nodes. We demonstrate how we realize networks with periodic, chaotic, and excitable dynamics and study their properties. Field-programmable gate arrays define a new experimental paradigm that holds great potential to test a large body of theoretical results on the dynamics of complex networks, which has been beyond reach of traditional experimental approaches.

  19. Autonomous spacecraft rendezvous and docking

    NASA Technical Reports Server (NTRS)

    Tietz, J. C.; Almand, B. J.

    1985-01-01

    A storyboard display is presented which summarizes work done recently in design and simulation of autonomous video rendezvous and docking systems for spacecraft. This display includes: photographs of the simulation hardware, plots of chase vehicle trajectories from simulations, pictures of the docking aid including image processing interpretations, and drawings of the control system strategy. Viewgraph-style sheets on the display bulletin board summarize the simulation objectives, benefits, special considerations, approach, and results.

  20. Star Power

    SciTech Connect

    2014-10-17

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  1. Star Power

    ScienceCinema

    None

    2014-11-18

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  2. Star Numbers and Constellations.

    ERIC Educational Resources Information Center

    Francis, Richard L.

    1993-01-01

    A number for which the number of digits categorizes the number is called a star number. A set of star numbers having a designated property is called a constellation. Discusses nature and cardinality of constellations made up of star square, star prime, star abundant, and star deficient numbers. Presents five related problems for exploration. (MDH)

  3. Autonomic Computing: Panacea or Poppycock?

    NASA Technical Reports Server (NTRS)

    Sterritt, Roy; Hinchey, Mike

    2005-01-01

    Autonomic Computing arose out of a need for a means to cope with rapidly growing complexity of integrating, managing, and operating computer-based systems as well as a need to reduce the total cost of ownership of today's systems. Autonomic Computing (AC) as a discipline was proposed by IBM in 2001, with the vision to develop self-managing systems. As the name implies, the influence for the new paradigm is the human body's autonomic system, which regulates vital bodily functions such as the control of heart rate, the body's temperature and blood flow-all without conscious effort. The vision is to create selfivare through self-* properties. The initial set of properties, in terms of objectives, were self-configuring, self-healing, self-optimizing and self-protecting, along with attributes of self-awareness, self-monitoring and self-adjusting. This self-* list has grown: self-anticipating, self-critical, self-defining, self-destructing, self-diagnosis, self-governing, self-organized, self-reflecting, and self-simulation, for instance.

  4. Semi autonomous mine detection system

    SciTech Connect

    Douglas Few; Roelof Versteeg; Herman Herman

    2010-04-01

    CMMAD is a risk reduction effort for the AMDS program. As part of CMMAD, multiple instances of semi autonomous robotic mine detection systems were created. Each instance consists of a robotic vehicle equipped with sensors required for navigation and marking, a countermine sensors and a number of integrated software packages which provide for real time processing of the countermine sensor data as well as integrated control of the robotic vehicle, the sensor actuator and the sensor. These systems were used to investigate critical interest functions (CIF) related to countermine robotic systems. To address the autonomy CIF, the INL developed RIK was extended to allow for interaction with a mine sensor processing code (MSPC). In limited field testing this system performed well in detecting, marking and avoiding both AT and AP mines. Based on the results of the CMMAD investigation we conclude that autonomous robotic mine detection is feasible. In addition, CMMAD contributed critical technical advances with regard to sensing, data processing and sensor manipulation, which will advance the performance of future fieldable systems. As a result, no substantial technical barriers exist which preclude – from an autonomous robotic perspective – the rapid development and deployment of fieldable systems.

  5. Autonomic Neuropathy in Diabetes Mellitus

    PubMed Central

    Verrotti, Alberto; Prezioso, Giovanni; Scattoni, Raffaella; Chiarelli, Francesco

    2014-01-01

    Diabetic autonomic neuropathy (DAN) is a serious and common complication of diabetes, often overlooked and misdiagnosed. It is a systemic-wide disorder that may be asymptomatic in the early stages. The most studied and clinically important form of DAN is cardiovascular autonomic neuropathy defined as the impairment of autonomic control of the cardiovascular system in patients with diabetes after exclusion of other causes. The reported prevalence of DAN varies widely depending on inconsistent definition, different diagnostic method, different patient cohorts studied. The pathogenesis is still unclear and probably multifactorial. Once DAN becomes clinically evident, no form of therapy has been identified, which can effectively stop or reverse it. Prevention strategies are based on strict glycemic control with intensive insulin treatment, multifactorial intervention, and lifestyle modification including control of hypertension, dyslipidemia, stop smoking, weight loss, and adequate physical exercise. The present review summarizes the latest knowledge regarding clinical presentation, epidemiology, pathogenesis, and management of DAN, with some mention to childhood and adolescent population. PMID:25520703

  6. Integrated System for Autonomous Science

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Sherwood, Robert; Tran, Daniel; Cichy, Benjamin; Davies, Ashley; Castano, Rebecca; Rabideau, Gregg; Frye, Stuart; Trout, Bruce; Shulman, Seth; Doggett, Thomas; Ip, Felipe; Greeley, Ron; Baker, Victor; Dohn, James; Boyer, Darrell

    2006-01-01

    The New Millennium Program Space Technology 6 Project Autonomous Sciencecraft software implements an integrated system for autonomous planning and execution of scientific, engineering, and spacecraft-coordination actions. A prior version of this software was reported in "The TechSat 21 Autonomous Sciencecraft Experiment" (NPO-30784), NASA Tech Briefs, Vol. 28, No. 3 (March 2004), page 33. This software is now in continuous use aboard the Earth Orbiter 1 (EO-1) spacecraft mission and is being adapted for use in the Mars Odyssey and Mars Exploration Rovers missions. This software enables EO-1 to detect and respond to such events of scientific interest as volcanic activity, flooding, and freezing and thawing of water. It uses classification algorithms to analyze imagery onboard to detect changes, including events of scientific interest. Detection of such events triggers acquisition of follow-up imagery. The mission-planning component of the software develops a response plan that accounts for visibility of targets and operational constraints. The plan is then executed under control by a task-execution component of the software that is capable of responding to anomalies.

  7. Feasibility Study of Utilizing Existing Infrared Array Cameras for Daylight Star Tracking on NASA's Ultra Long Duration Balloon (ULDB) Missions

    NASA Technical Reports Server (NTRS)

    Tueller, Jack (Technical Monitor); Fazio, Giovanni G.; Tolls, Volker

    2004-01-01

    The purpose of this study was to investigate the feasibility of developing a daytime star tracker for ULDB flights using a commercially available off-the-shelf infrared array camera. This report describes the system used for ground-based tests, the observations, the test results, and gives recommendations for continued development.

  8. Navigation and attitude reference for autonomous satellite launch and orbital operations

    NASA Technical Reports Server (NTRS)

    Kau, S. P.

    1979-01-01

    The navigation and attitude reference performance of a strapdown system are investigated for applications to autonomous satellite launch and orbital operations. It is assumed that satellite payloads are integrated into existing missile systems and that the boost, orbit insertion, and in-orbit operation of the satellite are performed autonomously without relying on external support facilities. Autonomous and long term accurate navigation and attitude reference are provided by a strapdown inertial navigation system aided by a star sensor and earth landmark sensor. Sensor measurement geometry and navigation and attitude update mechanizations are discussed. Performance analysis data are presented for following functional elements: (1) prelaunch alignment; (2) boost navigation and attitude reference; (3) post boost stellar attitude and navigation updates; (4) orbital navigation update using sensor landmark measurements; and (5) in-orbit stellar attitude update and gyro calibration. The system performances are shown to satisfy the requirements of a large class of satellite payload applications.

  9. Pixel telescope test in STAR at RHIC

    NASA Astrophysics Data System (ADS)

    Sun, Xiangming; Szelezniak, Michal; Greiner, Leo; Matis, Howard; Vu, Chinh; Stezelberger, Thorsten; Wieman, Howard

    2007-10-01

    The STAR experiment at RHIC is designing a new inner vertex detector called the Heavy Flavor Tracker (HFT). The HFT's innermost two layers is called the PIXEL detector which uses Monolithic Active Pixel Sensor technology (MAPS). To test the MAPS technology, we just constructed and tested a telescope. The telescope uses a stack of three MIMOSTAR2 chips, Each MIMOSTAR2 sensor, which was designed by IPHC, is an array of 132x128 pixels with a square pixel size of 30 μ. The readout of the telescope makes use of the ALICE DDL/SIU cards, which is compatible with the future STAR data acquisition system called DAQ1000. The telescope was first studied in a 1.2 GeV/c electron beam at LBNL's Advanced Light Source. Afterwards, the telescope was outside the STAR magnet, and then later inside it, 145 cm away from STAR's center. We will describe this first test of MAPS technology in a collider environment, and report on the occupancy, particle flux, and performance of the telescope.

  10. EVENT DATA STORAGE AND MANAGEMENT IN STAR.

    SciTech Connect

    PEREVOZTCHIKOV,V.

    2000-02-07

    The Solenoidal Tracker At RHIC (STAR) is a large acceptance collider detector, commissioned for operation at Brookhaven National Laboratory in 1999. STAR is designed to measure the momentum and identify several thousands of particles per event. About 300 Terabytes of data will be generated each year. To handle such a huge amount of data, sophisticated data structures and associated tools were developed. The main features of these data structures are: Data structure is a complicated but flexible set of C++ objects; All data objects are persistent, we do not maintain separate transient and persistent data structures; Persistence of data structure is based on ROOT[?] I/O implementation; Part of ROOT I/O was modified to meet STAR requirements; and The modification of ROOT I/O allows to support automatic schema evolution of STAR data structures. Automatic tools allow reading of old data into new environments. In this paper we present our experience with maintenance of big and complicated OO data structures, especially concerning schema evolution.

  11. Performance verification testing for HET wide-field upgrade tracker in the laboratory

    NASA Astrophysics Data System (ADS)

    Good, John; Hayes, Richard; Beno, Joseph; Booth, John; Cornell, Mark E.; Hill, Gary J.; Lee, Hanshin; Mock, Jason; Rafal, Marc; Savage, Richard; Soukup, Ian

    2010-07-01

    To enable the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), the McDonald Observatory (MDO) and the Center for Electro-mechanics (CEM) at the University of Texas at Austin are developing a new HET tracker in support of the Wide-Field Upgrade (WFU) and the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). The precision tracker is required to maintain the position of a 3,100 kg payload within ten microns of its desired position relative to the telescope's primary mirror. The hardware system to accomplish this has ten precision controlled actuators. Prior to installation on the telescope, full performance verification is required of the completed tracker in CEM's lab, without a primary mirror or the telescope's final instrument package. This requires the development of a laboratory test stand capable of supporting the completed tracker over its full range of motion, as well as means of measurement and methodology that can verify the accuracy of the tracker motion over full travel (4m diameter circle, 400 mm deep, with 9 degrees of tip and tilt) at a cost and schedule in keeping with the HET WFU requirements. Several techniques have been evaluated to complete this series of tests including: photogrammetry, laser tracker, autocollimator, and a distance measuring interferometer, with the laser tracker ultimately being identified as the most viable method. The design of the proposed system and its implementation in the lab is presented along with the test processes, predicted accuracy, and the basis for using the chosen method*.

  12. Autonomous Cryogenic Load Operations: Knowledge-Based Autonomous Test Engineer

    NASA Technical Reports Server (NTRS)

    Schrading, J. Nicolas

    2013-01-01

    The Knowledge-Based Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20 years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in the system. As part of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display of the entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledge base, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  13. Autonomous Cryogenic Load Operations: KSC Autonomous Test Engineer

    NASA Technical Reports Server (NTRS)

    Shrading, Nicholas J.

    2012-01-01

    The KSC Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20+ years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in. the system, As part.of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display ofthe entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledgebase, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  14. Downscaling the NOAA CarbonTracker Inversion for North America

    NASA Astrophysics Data System (ADS)

    Petron, G.; Andrews, A. E.; Chen, H.; Trudeau, M. E.; Eluszkiewicz, J.; Nehrkorn, T.; Henderson, J.; Sweeney, C.; Karion, A.; Masarie, K.; Bruhwiler, L.; Miller, J. B.; Miller, B. R.; Peters, W.; Gourdji, S. M.; Mueller, K. L.; Michalak, A. M.; Tans, P. P.

    2011-12-01

    We are developing a regional extension of the NOAA CarbonTracker CO2 data-assimilation system for a limited domain covering North America. The regional assimilation will use pre-computed and species-independent atmospheric sampling footprints from a Lagrangian Particle Dispersion Model. Each footprint relates an observed trace gas concentration to upwind fluxes. Once a footprint library has been computed, it can be used repeatedly to quickly test different inversion strategies and, importantly, for inversions using multiple species data (e.g., anthropogenic tracers such as radiocarbon and carbon monoxide and biological tracers such as carbonyl sulfide and stable isotopes of CO2). The current global CarbonTracker (CT) assimilation framework has some important limitations. For example, the assimilation adjusts scaling factors for different vegetation classes within large regions. This means, for example, that all crops within temperate North America are scaled together. There is currently no distinction between crops such as corn and sorghum, which utilize the C4 photosynthesis pathway and C3 crops like soybeans, wheat, cotton, etc. The optimization scales only the net CO2 flux, rather than adjusting photosynthesis and respiration fluxes separately, which limits the flexibility of the inversion and sometimes results in unrealistic diurnal cycles of CO2 flux. The time-series of residuals (CT - observed) for continental sites in North America reveals a persistent excess of CO2 during summer. This summertime positive bias is also apparent in the comparison of CT posterior CO2 with aircraft data and with data from Pacific marine boundary layer sites, suggesting that some of the problem may originate outside of North America. For the regional inversion, we will use footprints from the Stochastic Time-Inverted Lagrangian Transport Model driven by meteorological fields from a customized high-resolution simulation with the Weather Research Forecast (WRF) model. We will use

  15. Optimal Spacing of Dual-axis Trackers for Concentrating Photovoltaic Systems

    NASA Astrophysics Data System (ADS)

    Kim, Yong Sin; Winston, Roland

    2011-12-01

    The levelized cost of energy (LCOE) is widely used to compare the cost of energy generation across technologies. In a utility-scale concentrating photovoltaic (CPV) system, the spacing of dual-axis trackers must be balanced with total energy harvested from modules to minimize LCOE. In this paper, a spacing method of dual-axis trackers in a CPV system is presented. Based on the definition of LCOE, a cost function is defined and optimized in terms of spacing related parameters. Various methods to estimate hourly direct normal irradiance (DNI) are investigated and m-by-n tracker array configurations to minimize the cost function are discussed.

  16. Operation and performance of the ATLAS silicon micro-strip tracker

    SciTech Connect

    Pylypchenko, Y.

    2011-07-01

    The Semiconductor Tracker (SCT) is the key precision tracking device in ATLAS, made from silicon micro-strip detectors processed in the planar p-in-n technology. The completed SCT has been installed inside the ATLAS experimental hall since 2007 and has been operational since then. In this paper the current status of the Semiconductor Tracker is reviewed, including results from the data-taking periods in 2009 and 2010, and from the detector alignment. The emphasis is given to the performance of the Semiconductor Tracker with the LHC in collision mode and to the performance of individual electronic components. (authors)

  17. Onboard Autonomous Corrections for Accurate IRF Pointing.

    NASA Astrophysics Data System (ADS)

    Jorgensen, J. L.; Betto, M.; Denver, T.

    2002-05-01

    Over the past decade, the Noise Equivalent Angle (NEA) of onboard attitude reference instruments, has decreased from tens-of-arcseconds to the sub-arcsecond level. This improved performance is partly due to improved sensor-technology with enhanced signal to noise ratios, partly due to improved processing electronics which allows for more sophisticated and faster signal processing. However, the main reason for the increased precision, is the application of onboard autonomy, which apart from simple outlier rejection also allows for removal of "false positive" answers, and other "unexpected" noise sources, that otherwise would degrade the quality of the measurements (e.g. discrimination between signals caused by starlight and ionizing radiation). The utilization of autonomous signal processing has also provided the means for another onboard processing step, namely the autonomous recovery from lost in space, where the attitude instrument without a priori knowledge derive the absolute attitude, i.e. in IRF coordinates, within fractions of a second. Combined with precise orbital state or position data, the absolute attitude information opens for multiple ways to improve the mission performance, either by reducing operations costs, by increasing pointing accuracy, by reducing mission expendables, or by providing backup decision information in case of anomalies. The Advanced Stellar Compass's (ASC) is a miniature, high accuracy, attitude instrument which features fully autonomous operations. The autonomy encompass all direct steps from automatic health checkout at power-on, over fully automatic SEU and SEL handling and proton induced sparkle removal, to recovery from "lost in space", and optical disturbance detection and handling. But apart from these more obvious autonomy functions, the ASC also features functions to handle and remove the aforementioned residuals. These functions encompass diverse operators such as a full orbital state vector model with automatic cloud

  18. Converting neutron stars into strange stars

    NASA Technical Reports Server (NTRS)

    Olinto, A. V.

    1991-01-01

    If strange matter is formed in the interior of a neutron star, it will convert the entire neutron star into a strange star. The proposed mechanisms are reviewed for strange matter seeding and the possible strange matter contamination of neutron star progenitors. The conversion process that follows seeding and the recent calculations of the conversion timescale are discussed.

  19. Christmas star.

    NASA Astrophysics Data System (ADS)

    Biała, J.

    There are continuous attempts to identify the legendary Christmas Star with a real astronomical event accompanying the birth of Jesus from Nazareth. Unfortunately, the date of birth is difficult to establish on the basis of historical records with better accuracy than a few years. During that period a number of peculiar astronomical events were observed and it seem to be impossible to identify the right one unambiguously.

  20. Tele/Autonomous Robot For Nuclear Facilities

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Tso, Kam S.

    1994-01-01

    Fail-safe tele/autonomous robotic system makes it unnecessary for human technicians to enter nuclear-fuel-reprocessing facilities and other high-radiation or otherwise hazardous industrial environments. Used to carry out experiments as exchanging equipment modules, turning bolts, cleaning surfaces, and grappling turning objects by use of mixture of autonomous actions and teleoperation with either single arm or two cooperating arms. System capable of fully autonomous operation, teleoperation or shared control.