Deep-tow magnetic survey above large exhumed mantle domains of the eastern Southwest Indian ridge

NASA Astrophysics Data System (ADS)

Bronner, A.; Munschy, M.; Carlut, J. H.; Searle, R. C.; Sauter, D.; Cannat, M.

2011-12-01

The recent discovery of a new type of seafloor, the "smooth seafloor", formed with no or very little volcanic activity along the ultra-slow spreading Southwest Indian ridge (SWIR) shows an unexpected complexity in processes of generation of the oceanic lithosphere. There, detachment faulting is thought to be a mechanism for efficient exhumation of deep-seated mantle rocks. We present here a deep-tow geological-geophysical survey over smooth seafloor at the eastern SWIR (62-64°N) combining magnetic data, geology mapping from side-scan sonar images and results from dredge sampling. We introduce a new type of calibration approach for deep-tow fluxgate magnetometer. We show that magnetic data can be corrected from the magnetic effect of the vehicle with no recourse to its attitude (pitch, roll and heading) but only using the 3 components recorded by the magnetometer and an approximation of the scalar intensity of the Earth magnetic field. The collected dredge samples as well as the side-scan images confirm the presence of large areas of exhumed mantle-derived peridodites surrounded by a few volcanic constructions. This allows us to hypothesis that magnetic anomalies are caused by serpentinized peridotites or magmatic intrusions. We show that the magnetic signature of the smooth seafloor is clearly weaker than the surrounding volcanic areas. Moreover, the calculated magnetization of a source layer as well as the comparison between deep-tow and sea-surface magnetic data argue for strong East-West variability in the distribution of the magnetized sources. This variability may results from fluid-rocks interaction along the detachment faults as well as from the repartition of the volcanic material and thus questions the seafloor spreading origin of the corresponding magnetic anomalies. Finally, we provide magnetic arguments, as calculation of block rotation or spreading asymmetry in order to better constrain tectonic mechanisms that occur during the formation of this peculiar seafloor.

Performance metrics for state-of-the-art airborne magnetic and electromagnetic systems for mapping and detection of unexploded ordnance

NASA Astrophysics Data System (ADS)

Doll, William E.; Bell, David T.; Gamey, T. Jeffrey; Beard, Les P.; Sheehan, Jacob R.; Norton, Jeannemarie

2010-04-01

Over the past decade, notable progress has been made in the performance of airborne geophysical systems for mapping and detection of unexploded ordnance in terrestrial and shallow marine environments. For magnetometer systems, the most significant improvements include development of denser magnetometer arrays and vertical gradiometer configurations. In prototype analyses and recent Environmental Security Technology Certification Program (ESTCP) assessments using new production systems the greatest sensitivity has been achieved with a vertical gradiometer configuration, despite model-based survey design results which suggest that dense total-field arrays would be superior. As effective as magnetometer systems have proven to be at many sites, they are inadequate at sites where basalts and other ferrous geologic formations or soils produce anomalies that approach or exceed those of target ordnance items. Additionally, magnetometer systems are ineffective where detection of non-ferrous ordnance items is of primary concern. Recent completion of the Battelle TEM-8 airborne time-domain electromagnetic system represents the culmination of nearly nine years of assessment and development of airborne electromagnetic systems for UXO mapping and detection. A recent ESTCP demonstration of this system in New Mexico showed that it was able to detect 99% of blind-seeded ordnance items, 81mm and larger, and that it could be used to map in detail a bombing target on a basalt flow where previous airborne magnetometer surveys had failed. The probability of detection for the TEM-8 in the blind-seeded study area was better than that reported for a dense-array total-field magnetometer demonstration of the same blind-seeded site, and the TEM-8 system successfully detected these items with less than half as many anomaly picks as the dense-array total-field magnetometer system.

Improved Magnetic STAR Methods for Real-Time, Point-by-Point Localization of Unexploded Ordnance and Buried Mines

DTIC Science & Technology

2008-09-01

of magnetic UXO. The prototype STAR Sensor comprises: a) A cubic array of eight fluxgate magnetometers . b) A 24-channel data acquisition/signal...array (shaded boxes) of eight low noise Triaxial Fluxgate Magnetometers (TFM) develops 24 channels of vector B- field data. Processor hardware

Microfabricated optically pumped magnetometer arrays for biomedical imaging

NASA Astrophysics Data System (ADS)

Perry, A. R.; Sheng, D.; Krzyzewski, S. P.; Geller, S.; Knappe, S.

2017-02-01

Optically-pumped magnetometers have demonstrated magnetic field measurements as precise as the best superconducting quantum interference device magnetometers. Our group develops miniature alkali atom-based magnetic sensors using microfabrication technology. Our sensors do not require cryogenic cooling, and can be positioned very close to the sample, making these sensors an attractive option for development in the medical community. We will present our latest chip-scale optically-pumped gradiometer developed for array applications to image magnetic fields from the brain noninvasively. These developments should lead to improved spatial resolution, and potentially sensitive measurements in unshielded environments.

Flow noise of an underwater vector sensor embedded in a flexible towed array.

PubMed

Korenbaum, Vladimir I; Tagiltsev, Alexander A

2012-05-01

The objective of this work is to simulate the flow noise of a vector sensor embedded in a flexible towed array. The mathematical model developed, based on long-wavelength analysis of the inner space of a cylindrical multipole source, predicts the reduction of the flow noise of a vector sensor embedded in an underwater flexible towed array by means of intensimetric processing (cross-spectral density calculation of oscillatory velocity and sound-pressure-sensor responses). It is found experimentally that intensimetric processing results in flow noise reduction by 12-25 dB at mean levels and by 10-30 dB in fluctuations compared to a squared oscillatory velocity channel. The effect of flow noise suppression in the intensimetry channel relative to a squared sound pressure channel is observed, but only for frequencies above the threshold. These suppression values are 10-15 dB at mean noise levels and 3-6 dB in fluctuations. At towing velocities of 1.5-3 ms(-1) and an accumulation time of 98.3 s, the threshold frequency in fluctuations is between 30 and 45 Hz.

Measuring MEG closer to the brain: Performance of on-scalp sensor arrays

PubMed Central

Iivanainen, Joonas; Stenroos, Matti; Parkkonen, Lauri

2017-01-01

Optically-pumped magnetometers (OPMs) have recently reached sensitivity levels required for magnetoencephalography (MEG). OPMs do not need cryogenics and can thus be placed within millimetres from the scalp into an array that adapts to the invidual head size and shape, thereby reducing the distance from cortical sources to the sensors. Here, we quantified the improvement in recording MEG with hypothetical on-scalp OPM arrays compared to a 306-channel state-of-the-art SQUID array (102 magnetometers and 204 planar gradiometers). We simulated OPM arrays that measured either normal (nOPM; 102 sensors), tangential (tOPM; 204 sensors), or all components (aOPM; 306 sensors) of the magnetic field. We built forward models based on magnetic resonance images of 10 adult heads; we employed a three-compartment boundary element model and distributed current dipoles evenly across the cortical mantle. Compared to the SQUID magnetometers, nOPM and tOPM yielded 7.5 and 5.3 times higher signal power, while the correlations between the field patterns of source dipoles were reduced by factors of 2.8 and 3.6, respectively. Values of the field-pattern correlations were similar across nOPM, tOPM and SQUID gradiometers. Volume currents reduced the signals of primary currents on average by 10%, 72% and 15% in nOPM, tOPM and SQUID magnetometers, respectively. The information capacities of the OPM arrays were clearly higher than that of the SQUID array. The dipole-localization accuracies of the arrays were similar while the minimum-norm-based point-spread functions were on average 2.4 and 2.5 times more spread for the SQUID array compared to nOPM and tOPM arrays, respectively. PMID:28007515

HPMSS(High Precision Magnetic Survey System) and InterRidge

NASA Astrophysics Data System (ADS)

Isezaki, N.; Sayanagi, K.

2012-12-01

From the beginning of 1990s to the beginning of 2000s, the Japanese group of IntreRidge conducted many cruises for three component magnetic survey using Shipboard Three Component Magnetometer (STCM) and Deep Towed Three Component Magnetometer (DTCM) in the world wide oceans. We have been developing HPMSS during this time with support of Dr.Tamaki(the late representative of InterRidge Japan) who understood the advantages of three component geomagnetic anomalies (TCGA). TCGA measured by STCM determines the direction of geomagnetic anomaly lineations precisely at every point where TCGA were observed, which playes the important role in magnetic anomaly lineation analysis. Even in the beginning of 2000s, almost all marine magnetic scientists believed that the total intensity anomly (TIA) is the better data than TCGA for analysis because the scalar magnetometers (e.g. proton precession magnetometer) have the better accuracy than any other magnetometers (e.g.flux gate magnetometer (FGM)). We employed the high accrate gyroscope (e.g.ring lase gyroscope (RLG)/optical fiber gyroscope (OFG)) to improve the accuracy of STCM/DTCM equipped with FGM. Moreover we employed accurate and precise FGM which was selected among the market. Finally we developed the new magnetic survey system with high precision usable as airborn, shipboard and dee-ptowed magnetometers which we call HPMSS(High Precision Magnetic Survey System). As an optional equipment, we use LAN to communicate between a data aquisiitin part and a data logging part, and GPS for a position fix. For the deep-towed survey, we use the acoustic position fix (super short base line method) and the acoustic communication to monitor the DTCM status. First we used HPMSS to obtain the magnetization structure of the volcanic island, Aogashima located 300km south of Tokyo using a hellcopter in 2006 and 2009. Next we used HPMSS installed in DTCM in 2010,2011 and 2012 using R/V Bosei-maru belonging to Tokai University. Also we used HPMSS installed in AUV (automonous undersea vehicle), belonging to JAMSTEC in 2009,2010 and 2011. We have been emphasizing the importnace of TCGA compared to TIA because TIA does not obey the Laplace equation which means TIA is not harmonic, then we cannot apply the Fourier analysis on TIA. We will show the structure of three component magnetization of the mineral deposit in the volcanic thermal area in Izu-Ogasawara island Arc, called Hakurei Deposit. TCGA of DTCM and AUV survey data were used and the depth section and the vertical section of three components of magnetization of Hakurei Deposit area will be presented. We emphasize that reliable 3D structure of three component of magnetization was obtained from TCGA using HPMSS as the result of deep support of InterRidge Japan, especially deep support of Dr. Tamaki.

Deep Water Munitions Detection System

DTIC Science & Technology

2010-03-01

information if it does not display a currently valid OMB control number. 1. REPORT DATE MAR 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00...water systems to deeper water depths would result in even greater costs. While some of the cost escalation may be unavoidable, it is desirable to...magnetometers, spaced 61 cm apart, on a towed sensor platform. The sensor platform has active control elements that allow its depth to be changed

Field-Programmable Gate Array-based fluxgate magnetometer with digital integration

NASA Astrophysics Data System (ADS)

Butta, Mattia; Janosek, Michal; Ripka, Pavel

2010-05-01

In this paper, a digital magnetometer based on printed circuit board fluxgate is presented. The fluxgate is pulse excited and the signal is extracted by gate integration. We investigate the possibility to perform integration on very narrow gates (typically 500 ns) by using digital techniques. The magnetometer is based on field-programmable gate array (FPGA) card: we will show all the advantages and disadvantages, given by digitalization of fluxgate output voltage by means of analog-to-digital converter on FPGA card, as well as digitalization performed by external digitizer. Due to very narrow gate, it is shown that a magnetometer entirely based on a FPGA card is preferable, because it avoids noise due to trigger instability. Both open loop and feedback operative mode are described and achieved results are presented.

Three-dimensional analysis of magnetometer array data

NASA Technical Reports Server (NTRS)

Richmond, A. D.; Baumjohann, W.

1984-01-01

A technique is developed for mapping magnetic variation fields in three dimensions using data from an array of magnetometers, based on the theory of optimal linear estimation. The technique is applied to data from the Scandinavian Magnetometer Array. Estimates of the spatial power spectra for the internal and external magnetic variations are derived, which in turn provide estimates of the spatial autocorrelation functions of the three magnetic variation components. Statistical errors involved in mapping the external and internal fields are quantified and displayed over the mapping region. Examples of field mapping and of separation into external and internal components are presented. A comparison between the three-dimensional field separation and a two-dimensional separation from a single chain of stations shows that significant differences can arise in the inferred internal component.

MR 201104: Evaluation of Discrimination Technologies and Classification Results and MR 201157: Demonstration of MetalMapper Static Data Acquisition and Data Analysis

DTIC Science & Technology

2016-09-23

Acquisition and Data Analysis). EMI sensors, MetalMapper, man-portable Time-domain Electromagnetic Multi-sensor Towed Array Detection System (TEMTADS...California Department of Toxic Substances Control EM61 EM61-MK2 EMI electromagnetic induction ESTCP Environmental Security Technology Certification...SOP Standard Operating Procedure v TEMTADS Time-domain Electromagnetic Multi-sensor Towed Array Detection System man-portable 2x2 TOI target(s

A Low Frequency Electromagnetic Sensor for Underwater Geo-Location

DTIC Science & Technology

2011-05-01

used a set of commercially available fluxgate magnetometers to measure the magnetic field gradients associated with a magnetic dipole transmitter...insight into the operational capabilities of commercial fluxgate sensors. Figure 42. Applied Physics Systems 1540 magnetometer ...a magnetic field gradient receiver array. Highest quality gradient estimates were achieved with three vector magnetometers equally spaced and

Effects of tow transit on the efficacy of the Chicago Sanitary and Ship Canal Electric Dispersal Barrier System

USGS Publications Warehouse

Davis, Jeremiah J.; LeRoy, Jessica Z.; Shanks, Matthew R.; Jackson, Patrick Ryan; Engel, Frank; Murphy, Elizabeth; Baxter, Carey L.; McInerney, Michael K.; Barkowski, Nicholas A.

2017-01-01

In 2016, the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Army Corps of Engineers undertook a field study in the Chicago Sanitary and Ship Canal near Romeoville, Illinois to determine the influence of tow transit on the efficacy of the Electric Dispersal Barrier System (EDBS) in preventing the passage of juvenile fish (total length < 100 millimeters (mm)). Dual-frequency identification sonar data showed that large schools of juvenile fish (mean school size of 120 fish; n = 19) moved upstream and crossed the electric field of an array in the EDBS concurrent with downstream-bound (downbound) loaded tows in 89.5% of trials. Smaller schools of juvenile fish (mean school size of 98 fish; n = 15) moved downstream and crossed the electric field of an array in the EDBS concurrent with upstream-bound (upbound) loaded tows in 73.3% of trials. Observed fish passages through the EDBS were always opposite to the direction of tow movement, and not associated with propeller wash. These schools were not observed to breach the EDBS in the absence of a tow and showed no signs of incapacitation in the barrier during tow passage. Loaded tows transiting the EDBS create a return current of water flowing between the tow and the canal wall that typically travels opposite the direction of tow movement, and cause a decrease in the voltage gradient of the barrier of up to 88%. Return currents and decreases in voltage gradients induced by tow passage likely contributed to the observed fish passage through the EDBS. The efficacy of the EDBS in preventing the passage of small, wild fish is compromised while tows are moving across the barrier system. In particular, downbound tows moving through the EDBS create a pathway for the upstream movement of small fish, and therefore may increase the risk of transfer of invasive fishes from the Mississippi River Basin to the Great Lakes Basin.

Underwater Simultaneous EMI and Magnetometer System (USEMS)

DTIC Science & Technology

2011-02-01

advantages over other marine metal detectors . The first is that, because the sensors are affixed via a rigid boom instead of towed with a cable...Island free of metallic clutter, emplaced a test plot with 14 pipes ranging from 1.5 to 4 inches in diameter, measured the locations of items in it with... metallic contamination. 2.3 REGULATORY DRIVERS The primary driver is the continued need to develop tools to detect underwater MEC. The documented use

Tracking sperm whales with a towed acoustic vector sensor.

PubMed

Thode, Aaron; Skinner, Jeff; Scott, Pam; Roswell, Jeremy; Straley, Janice; Folkert, Kendall

2010-11-01

Passive acoustic towed linear arrays are increasingly used to detect marine mammal sounds during mobile anthropogenic activities. However, these arrays cannot resolve between signals arriving from the port or starboard without vessel course changes or multiple cable deployments, and their performance is degraded by vessel self-noise and non-acoustic mechanical vibration. In principle acoustic vector sensors can resolve these directional ambiguities, as well as flag the presence of non-acoustic contamination, provided that the vibration-sensitive sensors can be successfully integrated into compact tow modules. Here a vector sensor module attached to the end of a 800 m towed array is used to detect and localize 1813 sperm whale "clicks" off the coast of Sitka, AK. Three methods were used to identify frequency regimes relatively free of non-acoustic noise contamination, and then the active intensity (propagating energy) of the signal was computed between 4-10 kHz along three orthogonal directions, providing unambiguous bearing estimates of two sperm whales over time. These bearing estimates are consistent with those obtained via conventional methods, but the standard deviations of the vector sensor bearing estimates are twice those of the conventionally-derived bearings. The resolved ambiguities of the bearings deduced from vessel course changes match the vector sensor predictions.

Standardized UXO Technology Demonstration Site Scoring Record No. 931 Technology Type/Platform: Magnetometer MTADS/Towed

DTIC Science & Technology

2009-07-01

of the 2 acre site was cleared of all metallic items. This clearing of the metallic anomalies from the 2 acre Active Response Demonstration Site... metallic items. Once the NRL MTADS surveyed the site, ATC collected their data and conducted another intrusive operation in order to remove any additional...anomalies. During each clearance operation, the exact placement of all the metallic items was carefully measured in order to create a GT for each

A Web Server for MACCS Magnetometer Data

NASA Technical Reports Server (NTRS)

Engebretson, Mark J.

1998-01-01

NASA Grant NAG5-3719 was provided to Augsburg College to support the development of a web server for the Magnetometer Array for Cusp and Cleft Studies (MACCS), a two-dimensional array of fluxgate magnetometers located at cusp latitudes in Arctic Canada. MACCS was developed as part of the National Science Foundation's GEM (Geospace Environment Modeling) Program, which was designed in part to complement NASA's Global Geospace Science programs during the decade of the 1990s. This report describes the successful use of these grant funds to support a working web page that provides both daily plots and file access to any user accessing the worldwide web. The MACCS home page can be accessed at http://space.augsburg.edu/space/MaccsHome.html.

Real-Time Hand-Held Magnetometer Array

DTIC Science & Technology

2016-04-01

54 7.2.4 Detection : Probe Laser...oscillations in the F=4 hyperfine ground state and the probe beam is used to detect the oscillations. ............ 50 Figure 52. Sensor Larmor signal...level detectable by the magnetometer with a signal to noise ratio of 1:1

Correcting GOES-R Magnetometer Data for Stray Fields

NASA Technical Reports Server (NTRS)

Carter, Delano R.; Freesland, Douglas C.; Tadikonda, Sivakumara K.; Kronenwetter, Jeffrey; Todirita, Monica; Dahya, Melissa; Chu, Donald

2016-01-01

Time-varying spacecraft magnetic fields or stray fields are a problem for magnetometer systems. While constant fields can be removed with zero offset calibration, stray fields are difficult to distinguish from ambient field variations. Putting two magnetometers on a long boom and solving for both the ambient and stray fields can be a good idea, but this gradiometer solution is even more susceptible to noise than a single magnetometer. Unless the stray fields are larger than the magnetometer noise, simply averaging the two measurements is a more accurate approach. If averaging is used, it may be worthwhile to explicitly estimate and remove stray fields. Models and estimation algorithms are provided for solar array, arcjet and reaction wheel fields.

Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system.

PubMed

Jiang, Jia-Jia; Duan, Fa-Jie; Li, Yan-Chao; Hua, Xiang-Ning

2014-03-01

Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper.

Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system

NASA Astrophysics Data System (ADS)

Jiang, Jia-Jia; Duan, Fa-Jie; Li, Yan-Chao; Hua, Xiang-Ning

2014-03-01

Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper.

Investigating dynamical complexity in the time series of the upgraded ENIGMA magnetometer array using various entropy measures

NASA Astrophysics Data System (ADS)

Balasis, Georgios; Daglis, Ioannis A.; Papadimitriou, Constantinos; Melis, Nikolaos; Giannakis, Omiros; Kontoes, Charalampos

2016-04-01

The HellENIc GeoMagnetic Array (ENIGMA) is a network of 3 ground-based magnetometer stations in the areas of Trikala, Attiki and Lakonia in Greece that provides measurements for the study of geomagnetic pulsations, resulting from the solar wind - magnetosphere coupling. ENIGMA magnetometer array enables effective remote sensing of geospace dynamics and the study of space weather effects on the ground (i.e., Geomagnetically Induced Currents - GIC). ENIGMA contributes data to SuperMAG, a worldwide collaboration of organizations and national agencies that currently operate more than 300 ground-based magnetometers. ENIGMA is currently extended and upgraded receiving financial support through the national funding KRIPIS project and European Commission's BEYOND project. In particular, the REGPOT project BEYOND is an FP7 project that aims to maintain and expand the existing state-of-the-art interdisciplinary research potential, by Building a Centre of Excellence for Earth Observation based monitoring of Natural Disasters in south-eastern Europe, with a prospect to increase its access range to the wider Mediterranean region through the integrated cooperation with twining organizations. This study explores the applicability and effectiveness of a variety of computable entropy measures to the ENIGMA time series in order to investigate dynamical complexity between pre-storm activity and magnetic storms.

76 FR 53884 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to U.S. Navy Operations of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-30

... Array Sensor System Low Frequency Active Sonar AGENCY: National Marine Fisheries Service (NMFS... conducting operations of Surveillance Towed Array Sensor System (SURTASS) Low Frequency Active (LFA) sonar...

A 20-channel magnetoencephalography system based on optically pumped magnetometers

NASA Astrophysics Data System (ADS)

Borna, Amir; Carter, Tony R.; Goldberg, Josh D.; Colombo, Anthony P.; Jau, Yuan-Yu; Berry, Christopher; McKay, Jim; Stephen, Julia; Weisend, Michael; Schwindt, Peter D. D.

2017-12-01

We describe a multichannel magnetoencephalography (MEG) system that uses optically pumped magnetometers (OPMs) to sense the magnetic fields of the human brain. The system consists of an array of 20 OPM channels conforming to the human subject’s head, a person-sized magnetic shield containing the array and the human subject, a laser system to drive the OPM array, and various control and data acquisition systems. We conducted two MEG experiments: auditory evoked magnetic field and somatosensory evoked magnetic field, on three healthy male subjects, using both our OPM array and a 306-channel Elekta-Neuromag superconducting quantum interference device (SQUID) MEG system. The described OPM array measures the tangential components of the magnetic field as opposed to the radial component measured by most SQUID-based MEG systems. Herein, we compare the results of the OPM- and SQUID-based MEG systems on the auditory and somatosensory data recorded in the same individuals on both systems.

Process of Making Boron-Fiber Reinforced Composite Tape

NASA Technical Reports Server (NTRS)

Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor); Johnston, Norman J. (Inventor); Marchello, Joseph M. (Inventor)

2002-01-01

The invention is an apparatus and method for producing a hybrid boron reinforced polymer matrix composition from powder pre-impregnated fiber tow bundles and a linear array of boron fibers. The boron fibers are applied onto the powder pre-impregnated fiber tow bundles and then are processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the powder pre-impregnated fiber tow bundles with the boron fibers become a hybrid boron reinforced polymer matrix composite tape. A driving mechanism pulls the powder pre-impregnated fiber tow bundles with boron fibers through the processing line of the apparatus and a take-up spool collects the formed hybrid boron-fiber reinforced polymer matrix composite tape.

On-Time 3D Time-Domain EMI and Tensor Magnetic Gradiometry for UXO Detection and Discrimination

DTIC Science & Technology

2008-06-04

three-axis fluxgate magnetometers mounted on a tetrahedral structure as shown in figure 5.1.3.1. TMGS was intended to measure gradients of vector...manufacturer of the fluxgate magnetometers supplied specifications for each of the triaxial sensors (figure 5.3.2.25). Figure 5.3.2.25...Manufacturer’s specifications for the four triaxial fluxgate magnetometers used in the TMGS planar array. As shown previously in figure 5.3.2.4

76 FR 56407 - Notice of Availability of a Draft Supplemental Environmental Impact Statement/Supplemental...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-13

... Array Sensor System Low Frequency Active Sonar AGENCY: Department of the Navy, DoD. ACTION: Notice... analyses for the DoN's employment of Surveillance Towed Array Sensor System Low Frequency Active (SURTASS...

Studies of Polar Current Systems Using the IMS Scandinavian Magnetometer Array

NASA Astrophysics Data System (ADS)

Untiedt, J.; Baumjohann, W.

1993-09-01

As a contribution to the International Magnetospheric Study (IMS, 1976 1979) a two-dimensional array of 42 temporary magnetometer stations was run in Scandinavia, supplementary to the permanent observatories and concentrated in the northern part of the region. This effort aimed at the time-dependent (periods above about 100 s) determination of the two-dimensional structure of substorm-related magnetic fields at the Earth's surface with highest reasonable spatial resolution (about 100 km, corresponding to the height of the ionosphere) near the footpoints of field-aligned electric currents that couple the disturbed magnetosphere to the ionosphere at auroral latitudes. It has been of particular advantage for cooperative studies that not only simultaneous data were available from all-sky cameras, riometers, balloons, rockets, and satellites, but also from the STARE radar facility yielding colocated two-dimensional ionospheric electric field distributions. In many cases it therefore was possible to infer the three-dimensional regional structure of substorm-related ionospheric current systems. The first part of this review outlines the basic relationships and methods that have been used or have been developed for such studies. The second short part presents typical equivalent current patterns observed by the magnetometer array in the course of substorms. Finally we review main results of studies that have been based on the magnetometer array observations and on additional data, omitting studies on geomagnetic pulsations. These studies contributed to a clarification of the nature of auroral electrojets including the Harang discontinuity and of ionospheric current systems related to auroral features such as the break-up at midnight, the westward traveling surge, eastward drifting omega bands, and spirals.

Correcting GOES-R Magnetometer Data for Stray Fields

NASA Technical Reports Server (NTRS)

Carter, Delano; Freesland, Douglas; Tadikonda, Sivakumar; Kronenwetter, Jeffrey; Todirita, Monica; Dahya, Melissa; Chu, Donald

2016-01-01

Time-varying spacecraft magnetic fields, i.e. stray fields, are a problem for magnetometer systems. While constant fields can be removed by calibration, stray fields are difficult to distinguish from ambient field variations. Putting two magnetometers on a long boom and solving for both the ambient and stray fields can help, but this gradiometer solution is more sensitive to noise than a single magnetometer. As shown here for the R-series Geostationary Operational Environmental Satellites (GOES-R), unless the stray fields are larger than the noise, simply averaging the two magnetometer readings gives a more accurate solution. If averaging is used, it may be worthwhile to estimate and remove stray fields explicitly. Models and estimation algorithms to do so are provided for solar array, arcjet and reaction wheel fields.

Development of Geomagnetic Monitoring System Using a Magnetometer for the Field

NASA Astrophysics Data System (ADS)

Lee, Young-Cheol; Kim, Sung-Wook; Choi, Eun-Kyeong; Kim, In-Soo

2014-05-01

Three institutes including KMA (Korea Meteorological Administration), KSWC (Korean Space Weather Center) of NRRA (National Radio Research Agency) and KIGAM (Korea Institute of Geoscience and Mineral Resources) are now operating magnetic observatories. Those observatories observe the total intensity and three components of geomagnetic element. This paper comes up with a magnetic monitoring system now under development that uses a magnetometer for field survey. In monitoring magnetic variations in areas (active faults or volcanic regions), more reliable results can be obtained when an array of several magnetometers are used rather than a single magnetometer. In order to establish and operate a magnetometer array, such factors as expenses, convenience of the establishment and operation of the array should be taken into account. This study has come up with a magnetic monitoring system complete with a magnetometer for the field survey of our own designing. A magnetic monitoring system, which is composed of two parts. The one is a field part and the other a data part. The field part is composed of a magnetometer, an external memory module, a power supply and a set of data transmission equipment. The data part is a data server which can store the data transmitted from the field part, analyze the data and provide service to the web. This study has developed an external memory module for ENVI-MAG (Scintrex Ltd.) using an embedded Cortex-M3 board, which can be programmed, attach other functional devices (SD memory cards, GPS antennas for time synchronization, ethernet cards and so forth). The board thus developed can store magnetic measurements up to 8 Gbytes, synchronize with the GPS time and transmit the magnetic measurements to the data server which is now under development. A monitoring system of our own developing was installed in Jeju island, taking measurements throughout Korea. Other parts including a data transfer module, a server and a power supply using solar power will continue to be developed in the days to come. Acknowlegments This work was funded by the Korea Meteorological Administration Research and Development Program under Grant CATER 2006-5074

A Comparison of Some Signal-Processing Algorithms to Suppress Tow-Vessel Noise in a Towed Array, with Results from a Shallow-Water Trial

DTIC Science & Technology

1982-10-01

AKAL, T. , FIORI, S. , HASTRUP , O.F. transmission loss data for some SACLANTCEN SR-33, NATO CONFIDENTIAL. Research Centre, 1979. [AC C 950 788...different shallow-water areas with theoretical results provided by a three-fluid normal-mode propagation model. In: HASTRUP , O.F. and OLESEN, O.V. eds

Hydrates in the California Borderlands Revisited: Results from a Controlled-Source Electromagnetic Survey of the Santa Cruz Basin.

NASA Astrophysics Data System (ADS)

Kannberg, P. K.; Constable, S.

2014-12-01

Methane hydrate, an ice-like clathrate of water and methane, forms in shallow continental slope sediments, and is both a potential energy source and geologic hazard. Hydrates presence is traditionally inferred from the presence of the bottom simulating reflector (BSR), a seismic velocity inversion resulting from free gas pooling at the base of the hydrate stability field. The BSR is not a measure of hydrate, but rather a proxy for free gas presence. Whereas seismic methods are sensitive to velocity anomalies, controlled-source electromagnetic (CSEM) methods are sensitive to conductivity anomalies. The electrically resistive methane hydrate makes a favorable target for CSEM surveys, which are capable of detecting and potentially quantifying the presence of methane hydrate directly. Building on previous work 100km to the south in the San Nicolas Basin, we present initial results from a 6-day June 2014 survey in the Santa Cruz Basin, located 100km west of Los Angeles. CSEM surveys are performed by deep-towing an EM source that is transmitting a known signal; this signal is detected by towed and seafloor receivers. The initial EM source signal is altered by the electrical properties of the surrounding environment. Conductors such as brine and seawater are attenuating mediums, while resistors such as methane hydrate, gas, and oil are preservative of the original signal. Twenty-one seafloor receivers, as well as a 4 receiver towed array were deployed to image the resistivity structure of the Santa Cruz Basin. Using 30-year-old 2D seismic profiles as a guide, potential hydrate targets were identified, and the transmitter and array were towed over 150 km on 6 lines with 5 seafloor receivers each. The 6 towed lines were coincident with legacy seismic lines. The towed array is sensitive to sediment depths less than 1km, allowing for high data density through the hydrate stability field. The larger transmitter-receiver offsets of the seafloor receivers allow sensitivity to at least 3km below the seafloor. Combining the two data sets allows for both high resolution in the near-seafloor hydrate accumulations as well as imaging the potential gas-source regions of the hydrate field.

Geophysical studies in the vicinity of Blue Mountain and Pumpernickel Valley near Winnemucca, north-central Nevada

USGS Publications Warehouse

Ponce, David A.

2012-01-01

From May 2008 to September 2009, the U.S. Geological Survey (USGS) collected data from more than 660 gravity stations, 100 line-km of truck-towed magnetometer traverses, and 260 physical-property sites in the vicinity of Blue Mountain and Pumpernickel Valley, northern Nevada (fig. 1). Gravity, magnetic, and physical-property data were collected to study regional crustal structures as an aid to understanding the geologic framework of the Blue Mountain and Pumpernickel Valley areas, which in general, have implications for mineral- and geothermal-resource investigations throughout the Great Basin.

Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

NASA Astrophysics Data System (ADS)

Koppenjan, S.,; Martinez, M.

The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE's Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a 'chirped' FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.

Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koppenjan, S,; Martinez, M.

1994-06-01

The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteriamore » for the development of geophysical technologies and techniques. The US DOE`s Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ``chirped`` FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.« less

A 20-channel magnetoencephalography system based on optically pumped magnetometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borna, Amir; Carter, Tony R.; Goldberg, Josh D.

In this paper, we describe a multichannel magnetoencephalography (MEG) system that uses optically pumped magnetometers (OPMs) to sense the magnetic fields of the human brain. The system consists of an array of 20 OPM channels conforming to the human subject's head, a person-sized magnetic shield containing the array and the human subject, a laser system to drive the OPM array, and various control and data acquisition systems. We conducted two MEG experiments: auditory evoked magnetic field and somatosensory evoked magnetic field, on three healthy male subjects, using both our OPM array and a 306-channel Elekta-Neuromag superconducting quantum interference device (SQUID)more » MEG system. The described OPM array measures the tangential components of the magnetic field as opposed to the radial component measured by most SQUID-based MEG systems. Finally, herein, we compare the results of the OPM- and SQUID-based MEG systems on the auditory and somatosensory data recorded in the same individuals on both systems.« less

A 20-channel magnetoencephalography system based on optically pumped magnetometers

DOE PAGES

Borna, Amir; Carter, Tony R.; Goldberg, Josh D.; ...

2017-10-16

In this paper, we describe a multichannel magnetoencephalography (MEG) system that uses optically pumped magnetometers (OPMs) to sense the magnetic fields of the human brain. The system consists of an array of 20 OPM channels conforming to the human subject's head, a person-sized magnetic shield containing the array and the human subject, a laser system to drive the OPM array, and various control and data acquisition systems. We conducted two MEG experiments: auditory evoked magnetic field and somatosensory evoked magnetic field, on three healthy male subjects, using both our OPM array and a 306-channel Elekta-Neuromag superconducting quantum interference device (SQUID)more » MEG system. The described OPM array measures the tangential components of the magnetic field as opposed to the radial component measured by most SQUID-based MEG systems. Finally, herein, we compare the results of the OPM- and SQUID-based MEG systems on the auditory and somatosensory data recorded in the same individuals on both systems.« less

Array Simulation at the Bearing Stake Sites

DTIC Science & Technology

1981-04-01

C) The array was generally towed at 300 m depth. Four depth sensors on the array gave depth and tilt. With the exception of Site 1B the array was...Site 2, weights were added to the array to overcome its apparent buoyancy. The depth sensors failed on this run and the actual *ilt is not known. Data...horizontal axis title, " Sensor Group Separation," refers to posicion along che array. It .s equivalent to our simulated receiver depth with shallower

Detection of magnetic moment in thin films with a home-made vibrating sample magnetometer

NASA Astrophysics Data System (ADS)

Jordán, D.; González-Chávez, D.; Laura, D.; León Hilario, L. M.; Monteblanco, E.; Gutarra, A.; Avilés-Félix, L.

2018-06-01

This paper explores the optimization of an array of pick-up coils in a home-made vibrating sample magnetometer for the detection of magnetic moment in thin films. Sensitivity function of a 4-coils Mallinson configuration was numerically studied for the determination of the physical dimensions that enhance the sensitivity of the magnetometer. By performing numerical simulations using the Biot-Savart law combined with the principle of reciprocity we were able to determine the maximum values of sensitivity and the influence of the separation of the coils on the sensitivity function. After the optimization of the pick-up coils, the vibrating sample magnetometer was able to detect the magnetic moment of a 100 nm-thickness Fe19 Ni81 magnetic thin film along and perpendicular to the in-plane anisotropy easy axis. The implemented vibrating sample magnetometer is able to detect changes in the magnetic moment of ∼ 2 × 10-4 emu.

Standardized UXO Technology Demonstration Site Scoring Record NO. 934 Technology Type/Platform: EM61 MKII/Towed

DTIC Science & Technology

2009-07-01

nonferrous metallic objects. The applicability of the instrument for ordnance and explosives (OE) detection has been widely demonstrated at sites...was cleared of all metallic items. This clearing of the metallic anomalies from the 2 acre Active Response Demonstration Site was broken into three...with their Multiple Towed Array Detection System (MTADS). This system is known for its effectiveness and ability to detect metallic items. Once the

Electromagnetic induction imaging with a radio-frequency atomic magnetometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deans, Cameron; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk; Hussain, Sarah

2016-03-07

We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at room temperature, in an unshielded environment and without background subtraction. Conductivity maps of target objects exhibit not only excellent performance in terms of shape reconstruction but also demonstrate detection of sub-millimetric cracks and penetration of conductive barriers. The results presented here demonstrate the potential of a future generation of imaging instruments, which combine magnetic induction tomography and the unmatched performance of atomic magnetometers.

Analysis of vector magnetic anomalies over the Bayonnaise Knoll caldera obtained from a deep-sea magnetic exploration by AUV

NASA Astrophysics Data System (ADS)

Sayanagi, K.; Isezaki, N.; Matsuo, J.; Harada, M.; Kasaya, T.

2011-12-01

Geophysical surveys near the seafloor are very effective methods in order to investigate fine structures of the oceanic crust. Such surveys have increased in researches and developments of the seafloor, and will be more and more necessary in the future. For example, seabed resources like hydrothermal deposits have recently focused attention behind the international situation for natural resources like a competition of resources development. In order to estimate accurate abundance of those resources, the above detailed investigations should be needed because of low resolution of geophysical surveys on the sea and low efficiency of exploratory drilling. From such a viewpoint, we have been developing a measurement system for magnetic explorations using an AUV and a deep-tow system. The magnetic exploration system consists of two 3-axis flux-gate magnetometers, one/two Overhauser magnetometer(s), an optical fiber gyro, a main unit (control, communication, recording), and an onboard unit. These devices except for the onboard unit are installed in pressure cases (depth limit: 6000m). Thus this system can measure three components and total intensity of the geomagnetic field in the deep sea. In 2009, the first test of the magnetic exploration system was carried out in the Kumano Basin using AUV Urashima and towing vehicle Yokosuka Deep-Tow during the R/V Yokosuka YK09-09 cruise. In this test, we sank a small magnetic target to the seafloor, and examined how the system worked. As a result, we successfully detected magnetic anomaly of the target to confirm the expected performance of that in the sea. In 2010, the magnetic exploration system was further tested in the Bayonnaise Knoll area both using a titanium towing frame during the R/V Bosei-maru cruise and using AUV Urashima during the R/V Yokosuka YK10-17 cruise. The purpose of these tests was to evaluate the performance of the system in an actual hydrothermal deposit area for practical applications of that. The Bayonnaise Knoll is a submarine caldera with an outer rim of 2.5-3 km and a floor of 840-920 m, which is located in the Izu-Ogasawara arc. A large hydrothermal deposit, Hakurei deposit, lies in the southeast part of the caldera. In the R/V Bosei-maru cruise, we observed three components of magnetic anomalies at depths of 400-570 m along SE-NW and WE tracks across the caldera. In the R/V Yokosuka YK10-17 cruise, we observed three components and total intensity of magnetic anomalies at altitudes of 60-100 m around the Hakurei deposit and at depth of 500 m above the caldera. The analysis of these data is now energetically pushed forward. A 3D gridded data set of the vector magnetic anomaly in the latter cruise was made by solving the Laplace's equation in the areas where observation data were not available, which is the unique procedure for analysis of the vector anomalies. Several magnetization solutions have been so far obtained by successive approximation and inversion methods. We will here present the measurement of the geomagnetic field and analysis of magnetization structure in Bayonnaise Knoll caldera. Note that this study has been supported by the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

MWM-Array Characterization of Mechanical Damage and Corrosion

DOT National Transportation Integrated Search

2011-02-09

The MWM-Array is an inductive sensor that operates like a transformer in a plane. The MWMArray is based on the original MWM(R) (Meandering Winding Magnetometer) developed at MIT in the 1980s. A rapid multivariate inverse method converts impedance dat...

Observation of relativistic electron loss induced by EMIC waves in the outer radiation belt: Arase and PWING induction magnetometer array collaboration

NASA Astrophysics Data System (ADS)

Kurita, S.; Yoshizumi, M.; Kazuo, S.; Higashio, N.; Mitani, T.; Takashima, T.; Matsuoka, A.; Teramoto, M.; Shinohara, I.

2017-12-01

EMIC waves are generated by temperature anisotropy of energetic ions near the magnetic equator and satellite observations show that the waves tend to be observed on the dusk side and noon side magnetosphere. EMIC waves can propagate from the magnetosphere to the ground and they are observed by ground-based magnetometers as Pc1 pulsation. It has been pointed out that EMIC waves can resonate with relativistic electrons through anomalous cyclotron resonance, and cause strong pitch angle scattering of radiation belt electrons. It has been considered that precipitation loss of relativistic electrons by pitch angle scattering induced by EMIC waves is an important loss mechanism of radiation belt electrons. We report on the observation of relativistic electron loss observed by the Arase satellite on the dawn side magnetosphere during a geomagnetic disturbance, which is likely to be related to an EMIC wave activity. During the event, the EMIC wave activity in conjunction with the relativistic electron loss is identified from observation by the ground-based induction magnetometer array deployed by the PWING project. The magnetometer array observation reveals that EMIC waves are distributed in the wide magnetic local time range from the dusk to midnight sector. It is suggested that drifting relativistic electrons are scattered into the loss cone by the EMIC waves on the dusk to midnight sector before they arrive at the Arase satellite located on the dawn side. We will discuss the impact of loss caused by EMIC wave-induced precipitation loss on the overall flux variation of radiation belt electrons during the geomagnetic disturbance.

An EM System with Dynamic Multi-Axis Transmitter and Tensor Gradiometer Receiver

DTIC Science & Technology

2011-06-01

main difference between the spatial behavior of target anomalies measured with a magnetometer and those we measured with an EM system is in the nature...environmental and UXO applications, current efforts include the development of tensor magnetic gradiometers based on triaxial fluxgate technology by the USGS...Superconducting gradiometer/ Magnetometer Arrays and a Novel Signal Processing Technique. IEEE Trans. on Magnetics, MAG-11(2), 701-707. EM Tensor

An EM System With Dramatic Multi-Axis Transmitter and Tensor Gradiometer Receiver

DTIC Science & Technology

2011-06-01

Thus, the main difference between the spatial behavior of target anomalies measured with a magnetometer and those we measured with an EM system is in...current efforts include the development of tensor magnetic gradiometers based on triaxial fluxgate technology by the USGS (Snyder & Bracken, Development...Superconducting gradiometer/ Magnetometer Arrays and a Novel Signal Processing Technique. IEEE Trans. on Magnetics, MAG-11(2), 701-707. EM Tensor Gradiometer

Polarization maintaining fiber magnetic sensor based on the digital phase generated carrier technology

NASA Astrophysics Data System (ADS)

Zhang, Xueliang; Meng, Zhou; Hu, Zhengliang; Yang, Huayong; Song, Zhangqi; Hu, Yongming

2008-12-01

A polarization maintaining fiber (PMF) magnetic field sensor based on a digital phase generated carrier (PGC) technology is presented. A magnetic sensor constructed with two magnetostrictive strips attached on the sensing fiber is joined in the sensing arm of a fiber Michelson interferometer. The fiber optic interferometric system is made of all PMF, which inhibits the polarization-induced signal fading. The light source is a fiber laser which can be modulated directly. The PGC metnod is used to demodulate magnetic field signal avoiding phase induced interferometric signal fading, and ensure the sensing partto be all fiber structure. A fiber optic magnetic field sensor with appreciate size for the fiber optic hydrophone towed array is obtained, which can be used to sense the enviromental magnetic field along the sensing direction.This sensor is a good choice for the directional angle measurement through sensing the Earth magnetic field in the array shape measurement of a fiber optic hydrophone towed array.

Development of precise measurement systems for deep-sea electrical and magnetic explorations by ROV and AUV

NASA Astrophysics Data System (ADS)

Sayanagi, K.; Goto, T.; Harada, M.; Kasaya, T.; Sawa, T.; Nakajima, T.; Isezaki, N.; Takeuchi, A.; Nagao, T.; Matsuo, J.

2009-12-01

It is generally not easy to obtain the fine-scale structure of the oceanic crust with accuracy better than several tens of meters, because the deep sea prevents us from approaching the bottom in most parts of the oceans. The necessity of such detailed information, however, has increased in researches and developments of the ocean floor. For instance, it is essential in development of ocean floor resources like sea-floor hydrothermal deposits and methane hydrate in order to estimate accurate abundance of those resources. Therefore, it is very important to develop some instruments for precise measurements of the oceanic crust. From this standpoint, we have developed new measurement systems for electrical and magnetic explorations by Remotely Operated Vehicle (ROV) and Autonomous Underwater Vehicle (AUV). In our project, the main target is sea-floor hydrothermal deposits. We are working on research and development regarding measurement of the magnetic field with high resolution and high sampling rate, electrical exploration with accurately controlled source signals, electrical exploration tools for shallow and deep targets, versatile instruments of electrical and magnetic explorations with multi-platforms (deep-tow system, ROV, and AUV), comprehensive analyses of electrical, magnetic, acoustic and thermal data, and so on. We finished basic designs of the magnetic and electrical observation systems last year, and we have been manufacturing each instrument. So far, the first test of the magnetic exploration system was carried out in the Kumano Basin during the R/V Yokosuka cruise in July, 2009. In the test, a vector magnetometer on AUV “Urashima” and a scalar magnetometer hung below towing vehicle “Yokosuka Deep-Tow” successfully detected magnetic anomaly produced by an artificial magnetic body set up on the ocean floor. Details will be reported in another paper by Harada, M. et al. in this meeting. In addition, various performance tests will be planned for check and improvement of the observation systems. For instance, the vector magnetometer will be tested over a volcanic island using a helicopter. The electrical exploration system will be also tested using ROV “Kaiko 7000II” off the northeastern part of Japan during the R/V Kairei cruise. We will present the outline and the current state of the project in this presentation. Note that this project has been supported by the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

Portable Magnetic Gradiometer for Real-Time Localization and Classification of Unexploded Ordnance

DTIC Science & Technology

2006-09-01

classification (DLC) of Unexploded Ordnance (UXO). The portable gradiometer processes data from triaxial fluxgate magnetometers to develop sets of...low-noise (ង pTrms/√Hz) fluxgate -type Triaxial Magnetometers (TM). Paired sets of TMs comprise magnetic gradient sensor “axes” of the array that...channels of analog B-field data. The digitizers can be locked to the Global Positioning System to provide; a) Precise sensor channel timing, and b

Reduction of Magnetic Noise Associated with Ocean Waves by Sage-Husa Adaptive Kalman Filter in Towed Overhauser Marine Magnetic Sensor

NASA Astrophysics Data System (ADS)

GE, J.; Dong, H.; Liu, H.; Luo, W.

2016-12-01

In the extreme sea conditions and deep-sea detection, the towed Overhauser marine magnetic sensor is easily affected by the magnetic noise associated with ocean waves. We demonstrate the reduction of the magnetic noise by Sage-Husa adaptive Kalman filter. Based on Weaver's model, we analyze the induced magnetic field variations associated with the different ocean depths, wave periods and amplitudes in details. Furthermore, we take advantage of the classic Kalman filter to reduce the magnetic noise and improve the signal to noise ratio of the magnetic anomaly data. In the practical marine magnetic surveys, the extreme sea conditions can change priori statistics of the noise, and may decrease the effect of Kalman filtering estimation. To solve this problem, an improved Sage-Husa adaptive filtering algorithm is used to reduce the dependence on the prior statistics. In addition, we implement a towed Overhauser marine magnetometer (Figure 1) to test the proposed method, and it consists of a towfish, an Overhauser total field sensor, a console, and other condition monitoring sensors. Over all, the comparisons of simulation experiments with and without the filter show that the power spectral density of the magnetic noise is reduced to 0.1 nT/Hz1/2@1Hz from 1 nT/Hz1/2@1Hz. The contrasts between the Sage-Husa filter and the classic Kalman filter (Figure 2) show the filtering accuracy and adaptive capacity are improved.

Variations of High-Latitude Geomagnetic Pulsation Frequencies: A Comparison of Time-of-Flight Estimates and IMAGE Magnetometer Observations

NASA Astrophysics Data System (ADS)

Sandhu, J. K.; Yeoman, T. K.; James, M. K.; Rae, I. J.; Fear, R. C.

2018-01-01

The fundamental eigenfrequencies of standing Alfvén waves on closed geomagnetic field lines are estimated for the region spanning 5.9≤L < 9.5 over all MLT (Magnetic Local Time). The T96 magnetic field model and a realistic empirical plasma mass density model are employed using the time-of-flight approximation, refining previous calculations that assumed a relatively simplistic mass density model. An assessment of the implications of using different mass density models in the time-of-flight calculations is presented. The calculated frequencies exhibit dependences on field line footprint magnetic latitude and MLT, which are attributed to both magnetic field configuration and spatial variations in mass density. In order to assess the validity of the time-of-flight calculated frequencies, the estimates are compared to observations of FLR (Field Line Resonance) frequencies. Using IMAGE (International Monitor for Auroral Geomagnetic Effects) ground magnetometer observations obtained between 2001 and 2012, an automated FLR identification method is developed, based on the cross-phase technique. The average FLR frequency is determined, including variations with footprint latitude and MLT, and compared to the time-of-flight analysis. The results show agreement in the latitudinal and local time dependences. Furthermore, with the use of the realistic mass density model in the time-of-flight calculations, closer agreement with the observed FLR frequencies is obtained. The study is limited by the latitudinal coverage of the IMAGE magnetometer array, and future work will aim to extend the ground magnetometer data used to include additional magnetometer arrays.

77 FR 34041 - Environmental Impacts Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... Supplement, USN, 00, Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) Sonar Systems, Updated and Additional Information on Employment of Four SURTASS LFA Sonar Systems for Routine Training...

Maui Aeromagnetic Survey

DOE Data Explorer

Akerley, John

2010-04-17

Map, image, and data files, and a summary report of a high-resolution aeromagnetic survey of southern Maui, Hawai'i completed by EDCON-PRJ, Inc. for Ormat Nevada Inc using an helicopter and a towed sensor array.

76 FR 51972 - Environmental Impacts Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-19

... as a Proof of Concept for the Restoration of Shallow Water Habitat that Currently Support Fish and.... 20110269, Draft Supplement, USN, 00, Surveillance Towed Array Sensor System Low Frequency Active (SURTASS...

Fetal magnetocardiography measurements with an array of microfabricated optically pumped magnetometers

NASA Astrophysics Data System (ADS)

Alem, Orang; Sander, Tilmann H.; Mhaskar, Rahul; LeBlanc, John; Eswaran, Hari; Steinhoff, Uwe; Okada, Yoshio; Kitching, John; Trahms, Lutz; Knappe, Svenja

2015-06-01

Following the rapid progress in the development of optically pumped magnetometer (OPM) technology for the measurement of magnetic fields in the femtotesla range, a successful assembly of individual sensors into an array of nearly identical sensors is within reach. Here, 25 microfabricated OPMs with footprints of 1 cm3 were assembled into a conformal array. The individual sensors were inserted into three flexible belt-shaped holders and connected to their respective light sources and electronics, which reside outside a magnetically shielded room, through long optical and electrical cables. With this setup the fetal magnetocardiogram of a pregnant woman was measured by placing two sensor belts over her abdomen and one belt over her chest. The fetal magnetocardiogram recorded over the abdomen is usually dominated by contributions from the maternal magnetocardiogram, since the maternal heart generates a much stronger signal than the fetal heart. Therefore, signal processing methods have to be applied to obtain the pure fetal magnetocardiogram: orthogonal projection and independent component analysis. The resulting spatial distributions of fetal cardiac activity are in good agreement with each other. In a further exemplary step, the fetal heart rate was extracted from the fetal magnetocardiogram. Its variability suggests fetal activity. We conclude that microfabricated optically pumped magnetometers operating at room temperature are capable of complementing or in the future even replacing superconducting sensors for fetal magnetocardiography measurements.

Design and analysis of miniature tri-axial fluxgate magnetometer

NASA Astrophysics Data System (ADS)

Zhi, Menghui; Tang, Liang; Qiao, Donghai

2017-02-01

The detection technology of weak magnetic field is widely used in Earth resource survey and geomagnetic navigation. Useful magnetic field information can be obtained by processing and analyzing the measurement data from magnetic sensors. A miniature tri-axial fluxgate magnetometer is proposed in this paper. This miniature tri-axial fluxgate magnetometer with ring-core structure has a dynamic range of the Earth’s field ±65,000 nT, resolution of several nT. It has three independent parts placed in three perpendicular planes for measuring three orthogonal magnetic field components, respectively. A field-programmable gate array (FPGA) is used to generate stimulation signal, analog-to-digital (A/D) convertor control signal, and feedback digital-to-analog (D/A) control signal. Design and analysis details are given to improve the dynamic range, sensitivity, resolution, and linearity. Our prototype was measured and compared with a commercial standard Magson fluxgate magnetometer as a reference. The results show that our miniature fluxgate magnetometer can follow the Magson’s change trend well. When used as a magnetic compass, our prototype only has ± 0.3∘ deviation compared with standard magnetic compass.

Multiplexed HTS rf SQUID magnetometer array for eddy current testing of aircraft rivet joints

NASA Astrophysics Data System (ADS)

Gärtner, S.; Krause, H.-J.; Wolters, N.; Lomparski, D.; Wolf, W.; Schubert, J.; Kreutzbruck, M. v.; Allweins, K.

2002-05-01

Using three rf SQUID magnetometers, a multiplexed SQUID array was implemented. The SQUIDs are positioned in line with 7 mm spacing and operated using one feedback electronics with sequential read out demodulation at different radio frequencies (rf). The cross-talk between SQUID channels was determined to be negligible. To show the performance of the SQUID array, eddy current (EC) measurements of aluminum aircraft samples in conjunction with a differential (double-D) EC excitation and lock-in readout were carried out. With computer-controlled continuous switching of the SQUIDs during the scan, three EC signal traces of the sample are obtained simultaneously. We performed measurements with an EC excitation frequency of 135 Hz to localize an artificial crack (sawcut flaw) of 20 mm length in an aluminum sheet with 0.6 mm thickness. The flaw was still detected when covered with aluminum of up to 10 mm thickness. In addition, measurements with varying angles between scanning direction and flaw orientation are presented.

Advanced Geophysical Classification with the Marine Towed Array

NASA Astrophysics Data System (ADS)

Steinhurst, D.; Harbaugh, G.; Keiswetter, D.; Bell, T. W.; Massey, G.; Wright, D.

2017-12-01

The Marine Towed Array, or MTA, is an underwater dual-mode sensor array that has been successfully deployed at multiple marine venues in support of Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) demonstrations beginning in 2004. It provided both marine electromagnetic and marine magnetic sensors for detection and mapping of underwater UXO. The EMI sensor array was based on older technology, which in several ESTCP demonstrations has not been able to support advanced geophysical classification (AGC). Under ESTCP funding, the U.S. Naval Research Laboratory is in the process of upgrading the MTA with modern, advanced electromagnetic (EMI) electronics and replacing the sensor array with a modern, multistatic array design. A half-scale version of the proposed array has been built and tested on land. Six tri-axial receiver cubes were placed inside two- and three- transmit coil configurations in equivalent positions to design locations for the MTA wing. The responses of a variety of munitions items and test spheres were measured over a range of target-to-array geometries and in both static and simulated dynamic data collection modes. The multi-transmit coil configuration was shown to provide enhanced single-pass classification performance over the original single coil design, particularly as a function of target location relative to the centerline. The ability to go beyond anomaly detection and additionally classify detected anomalies from survey data would dramatically improve the state of the art for underwater UXO remediation by reducing costs and improving the efficiency of these efforts. The results of our efforts to return the MTA to service and validating the new EMI array's design for UXO detection and classification in the underwater environment will be the focus of this presentation.

50 CFR 216.180 - Specified activity.

Code of Federal Regulations, 2011 CFR

2011-10-01

....180 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Taking of Marine Mammals Incidental to Navy Operations of Surveillance Towed Array Sensor System...

50 CFR 216.180 - Specified activity.

Code of Federal Regulations, 2010 CFR

2010-10-01

....180 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Taking of Marine Mammals Incidental to Navy Operations of Surveillance Towed Array Sensor System...

Atomic magnetometer for human magnetoencephalograpy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwindt, Peter; Johnson, Cort N.

2010-12-01

We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, themore » evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.« less

Operational field evaluation of the PAC-MAG man-portable magnetometer array

NASA Astrophysics Data System (ADS)

Keranen, Joe; Topolosky, Zeke; Schultz, Gregory; Miller, Jonathan

2013-06-01

Detection and discrimination of unexploded ordnance (UXO) in areas of prior conflict is of high importance to the international community and the United States government. For humanitarian applications, sensors and processing methods need to be robust, reliable, and easy to train and implement using indigenous UXO removal personnel. This paper describes system characterization, system testing, and a continental United States (CONUS) Operational Field Evaluations (OFE) of the PAC-MAG man-portable UXO detection system. System testing occurred at a government test facility in June, 2010 and December, 2011 and the OFE occurred at the same location in June, 2012. NVESD and White River Technologies personnel were present for all testing and evaluation. The PAC-MAG system is a manportable magnetometer array for the detection and characterization of ferrous UXO. System hardware includes four Cesium vapor magnetometers for detection, a Real-time Kinematic Global Position System (RTK-GPS) for sensor positioning, an electronics module for merging array data and WiFi communications and a tablet computer for transmitting and logging data. An odometer, or "hipchain" encoder, provides position information in GPS-denied areas. System software elements include data logging software and post-processing software for detection and characterization of ferrous anomalies. The output of the post-processing software is a dig list containing locations of potential UXO(s), formatted for import into the system GPS equipment for reacquisition of anomalies. Results from system characterization and the OFE will be described.

Ionospheric and Birkeland current distributions inferred from the MAGSAT magnetometer data

NASA Technical Reports Server (NTRS)

Zanetti, L. J.; Potemra, T. A.; Baumjohann, W.

1983-01-01

Ionospheric and field-aligned sheet current density distributions are presently inferred by means of MAGSAT vector magnetometer data, together with an accurate magnetic field model. By comparing Hall current densities inferred from the MAGSAT data and those inferred from simultaneously recorded ground based data acquired by the Scandinavian magnetometer array, it is determined that the former have previously been underestimated due to high damping of magnetic variations with high spatial wave numbers between the ionosphere and the MAGSAT orbit. Among important results of this study is noted the fact that the Birkeland and electrojet current systems are colocated. The analyses have shown a tendency for triangular rather than constant electrojet current distributions as a function of latitude, consistent with the statistical, uniform regions 1 and 2 Birkeland current patterns.

The QuakeFinder Magnetometer Network - a Platform for Earth and Space Science Research

NASA Astrophysics Data System (ADS)

Bleier, T.; Kappler, K. N.; Schneider, D.

2016-12-01

QuakeFinder (QF) is a humanitarian research and development project attempting to characterize earth-emitting electromagnetic (EM) signals as potential precursors to earthquakes. Beginning in 2005, QF designed, built, deployed and now maintains an array of 165 remote monitoring stations in 6 countries (US/California, Taiwan, Greece, Indonesia, Peru and Chile). Having amassed approximately 70 TB of data and greater than 140 earthquakes (M4+), QF is focused on the data analysis and signal processing algorithms in our effort to enable a forecasting capability. QF's autonomous stations, located along major fault lines, collect and transmit electromagnetic readings from 3-axis induction magnetometers and positive/negative ion sensors, a geophone, as well as various station health status and local conditions. The induction magnetometers, oriented N-S,E-W and vertically, have a 40 nT range and 1 pT sensitivity. Data is continuously collected at 50 samples/sec (sps), GPS time-stamped and transmitted, primarily through cell phone networks, to our data center in Palo Alto, California. The induction magnetometers routinely detect subtle geomagnetic and ionospheric disturbances as observed worldwide. QF seeks to make available both historic data and the array platform to strategic partners in the EM-related research and operation fields. The QF system will be described in detail with examples of local and regional geomagnetic activity. The stations are robust and will be undergoing a system-level upgrade in the near future. Domestically, QF maintains a 98% `up time' among the 120 stations in California while internationally our metric is typically near 80%. Irregular cell phone reception is chief among the reasons for outages although little data has been lost as the stations can store up to 90 days of data. These data are retrieved by QF personnel or, when communication is reestablished, the QF data ingest process automatically updates the database. Planned station upgrades include a new processor and ARM board with additional data channels, increased robustness in station health monitoring and self-recovery features, induction magnetometers with a deeper frequency range, and possibly the addition of 3-axis flux gate magnetometers to expand the measurement range to 2000 nT.

Deep-towed CSEM survey of gas hydrates in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Kannberg, P.; Constable, S.

2017-12-01

Controlled source electromagnetic (CSEM) surveys are increasingly being used to remotely detect hydrate deposits in seafloor sediments. CSEM methods are sensitive to sediment pore space resistivity, such as when electrically resistive hydrate displaces the electrically conductive pore fluid, increasing the bulk resistivity of the sediment. In July 2017, a two-week research cruise using an upgraded and expanded "Vulcan" towed receiver system collected over 250 line km of data at four sites in the Gulf of Mexico (GoM) thought to have hydrate bearing sediments. Hydrate bearing horizons at the survey sites ranged from 400-700 m below seafloor. Modeling suggested an array with source receiver offsets of up to 1600 m would be needed to properly image the deep hydrate. A deep towed electromagnetic transmitter outputting 270 Amps was towed 100 m above seafloor. Six Vulcan receivers, each recording three-axis electric field data, were towed at 200 m intervals from 600-1600 m behind the transmitter. The four sites surveyed, Walker Ridge 313, Orca Basin, Mad Dog, and Green Canyon 955, are associated with the upcoming GOM^2 coring operation scheduled for 2020. Wells at WR313 and GC955 were logged as part of a joint industry drilling project in 2009 and will be used to ground truth our inversion results. In 2008, WR313 and GC955 were surveyed using traditional CSEM seafloor receivers, accompanied by a single prototype Vulcan towed receiver. This prior survey will allow comparison of results from a seafloor receiver survey with those from a towed receiver survey. Seismic data has been collected at all the sites, which will be used to constrain inversions. In addition to the four hydrate sites surveyed, two lines were towed over Green Knoll, a deep-water salt dome located between Mad Dog and GC955. Presented here are initial results from our recent cruise.

Fiber Optic Towed Arrays

DTIC Science & Technology

2007-01-01

Fabry - Perot inter- ferometers. The hydrophones are passively multiplexed both in time and in wavelength to allow hundreds of channels to be carried...sensing fiber wrapped on a solid plastic mandrel. For this demon- stration, the laser and the demodulation electronics were collocated with the fiber

77 FR 6771 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to U.S. Navy Operations of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

... Towed Array Sensor System (SURTASS) Low Frequency Active (LFA) sonar in areas of the world's oceans... Natural Resources Defense Council, NMFS has decided to extend the public comment period by 15 days, to...

The Danish Greenland Magnetometer Chain - Status and Outlook

NASA Astrophysics Data System (ADS)

Behlke, R.

2016-12-01

DTU Space operates the Greenland magnetometer array, including 19 variometer stations whereof 3 are geomagnetic observatories. This array consists of a West Coast Chain with 13 stations including three observatories between 77.47 and 61.16 geographic North. On the East Coast 5 variometer stations are located between 81.6 and 65.6 geographic North. The Greenland Array covers polar cap, cusp and auroral regions. These data allow the monitoring of electromagnetic processes in the polar ionosphere and magnetosphere, and are a significant contribution to global data sets. The vast majority of the sensors now employed are the Danish FGE 3-axis linear-core fluxgate magnetometers designed and built under the supervision of Ole Rasmussen and later Lars William Pedersen. They are optimized for long-term stability (observatory-quality instruments) rather than high sensitivity. The stations use 16 bit A/D converters with 20s or 1s sampling rate, optimized for 1 minute mean data. Hence, the rms-noise is approximately 0.1 nT in the 1 mHz - 1 Hz band, the time accuracy is 1s and the final resolution is 0.25 nT for most data at 20s sampling rate and 0.125 nT for most data at 1s sampling rate. During setup, the sensor axes are oriented along local magnetic north (H), local magnetic east (E) and vertical down (Z). Sensors at some stations are equipped with a suspension which guarantees vertical alignment. The instruments run fully automatically and require (normally) no manual intervention. All stations use the FGE vector magnetometer. Greenland magnetometer data has been aquired in digital form since 1981. From 1981 through 1990 all stations recorded with 1-min sampling rate. In 1986 the acquisition systems was gradually modified in order to record with 20-s sampling rate. Modification was completed by 1991, and since then all stations run at 20-s sampling rate. In 1999 acquisition system was made capable to record at 1-s sampling in addition to the continued 20-s sampoling rate. In 2001 most stations were upgraded, and in the summer of 2002 the upgrade was completed. Now all stations have laptops as dataloggers recording at 1Hz. In this presentation, we provide a status overview of the chain and its role within the G-ESC.

Surface Current Density Mapping for Identification of Gastric Slow Wave Propagation

PubMed Central

Bradshaw, L. A.; Cheng, L. K.; Richards, W. O.; Pullan, A. J.

2009-01-01

The magnetogastrogram records clinically relevant parameters of the electrical slow wave of the stomach noninvasively. Besides slow wave frequency, gastric slow wave propagation velocity is a potentially useful clinical indicator of the state of health of gastric tissue, but it is a difficult parameter to determine from noninvasive bioelectric or biomagnetic measurements. We present a method for computing the surface current density (SCD) from multichannel magnetogastrogram recordings that allows computation of the propagation velocity of the gastric slow wave. A moving dipole source model with hypothetical as well as realistic biomagnetometer parameters demonstrates that while a relatively sparse array of magnetometer sensors is sufficient to compute a single average propagation velocity, more detailed information about spatial variations in propagation velocity requires higher density magnetometer arrays. Finally, the method is validated with simultaneous MGG and serosal EMG measurements in a porcine subject. PMID:19403355

Observations of interplanetary dust by the Juno magnetometer investigation

NASA Astrophysics Data System (ADS)

Benn, M.; Jorgensen, J. L.; Denver, T.; Brauer, P.; Jorgensen, P. S.; Andersen, A. C.; Connerney, J. E. P.; Oliversen, R.; Bolton, S. J.; Levin, S.

2017-05-01

One of the Juno magnetometer investigation's star cameras was configured to search for unidentified objects during Juno's transit en route to Jupiter. This camera detects and registers luminous objects to magnitude 8. Objects persisting in more than five consecutive images and moving with an apparent angular rate of between 2 and 18,000 arcsec/s were recorded. Among the objects detected were a small group of objects tracked briefly in close proximity to the spacecraft. The trajectory of these objects demonstrates that they originated on the Juno spacecraft, evidently excavated by micrometeoroid impacts on the solar arrays. The majority of detections occurred just prior to and shortly after Juno's transit of the asteroid belt. This rather novel detection technique utilizes the Juno spacecraft's prodigious 60 m2 of solar array as a dust detector and provides valuable information on the distribution and motion of interplanetary (>μm sized) dust.

Evaluation of realistic layouts for next generation on-scalp MEG: spatial information density maps.

PubMed

Riaz, Bushra; Pfeiffer, Christoph; Schneiderman, Justin F

2017-08-01

While commercial magnetoencephalography (MEG) systems are the functional neuroimaging state-of-the-art in terms of spatio-temporal resolution, MEG sensors have not changed significantly since the 1990s. Interest in newer sensors that operate at less extreme temperatures, e.g., high critical temperature (high-T c ) SQUIDs, optically-pumped magnetometers, etc., is growing because they enable significant reductions in head-to-sensor standoff (on-scalp MEG). Various metrics quantify the advantages of on-scalp MEG, but a single straightforward one is lacking. Previous works have furthermore been limited to arbitrary and/or unrealistic sensor layouts. We introduce spatial information density (SID) maps for quantitative and qualitative evaluations of sensor arrays. SID-maps present the spatial distribution of information a sensor array extracts from a source space while accounting for relevant source and sensor parameters. We use it in a systematic comparison of three practical on-scalp MEG sensor array layouts (based on high-T c SQUIDs) and the standard Elekta Neuromag TRIUX magnetometer array. Results strengthen the case for on-scalp and specifically high-T c SQUID-based MEG while providing a path for the practical design of future MEG systems. SID-maps are furthermore general to arbitrary magnetic sensor technologies and source spaces and can thus be used for design and evaluation of sensor arrays for magnetocardiography, magnetic particle imaging, etc.

Flux-coherent series SQUID array magnetometers operating above 77 K with superior white flux noise than single-SQUIDs at 4.2 K

NASA Astrophysics Data System (ADS)

Chesca, Boris; John, Daniel; Mellor, Christopher J.

2015-10-01

A very promising direction to improve the sensitivity of magnetometers based on superconducting quantum interference devices (SQUIDs) is to build a series-array of N non-interacting SQUIDs operating flux-coherently, because in this case their voltage modulation depth, ΔV, linearly scales with N whereas the white flux noise SΦ1/2 decreases as 1/N1/2. Here, we report the realization of both these improvements in an advanced layout of very large SQUID arrays made of YBa2Cu3O7. Specially designed with large area narrow flux focusers for increased field sensitivity and improved flux-coherency, our arrays have extremely low values for SΦ1/2 between (0.25 and 0.44) μΦ0/Hz1/2 for temperatures in the range (77-83) K. In this respect, they outperform niobium/aluminium trilayer technology-based single-SQUIDs operating at 4.2 K. Moreover, with values for ΔV and transimpedance in the range of (10-17) mV and (0.3-2.5) kΩ, respectively, a direct connection to a low-noise room temperature amplifier is allowed, while matching for such readout is simplified and the available bandwidth is greatly increased. These landmark performances suggest such series SQUID arrays are ideal candidates to replace single-SQUIDs operating at 4.2 K in many applications.

Target Tracking Onboard an Autonomous Underwater Vehicle: Determining Optimal Towed Array Heading in an Anisotropic Noise Field

DTIC Science & Technology

2007-09-01

The geometry depicted in Figure 2-1 and defined in (9) governs the relationship between the two coordinate systems. We obtain the three-dimensional...node = ’ Unicorn ’ else if (v_id == 4) node = ’Macrura

Baird's beaked whale echolocation signals.

PubMed

Baumann-Pickering, Simone; Yack, Tina M; Barlow, Jay; Wiggins, Sean M; Hildebrand, John A

2013-06-01

Echolocation signals from Baird's beaked whales were recorded during visual and acoustic shipboard surveys of cetaceans in the California Current ecosystem and with autonomous, long-term recorders in the Southern California Bight. The preliminary measurement of the visually validated Baird's beaked whale echolocation signals from towed array data were used as a basis for identifying Baird's signals in the autonomous recorder data. Two distinct signal types were found, one being a beaked whale-like frequency modulated (FM) pulse, the other being a dolphin-like broadband click. The median FM inter-pulse interval was 230 ms. Both signal types showed a consistent multi-peak structure in their spectra with peaks at ~9, 16, 25, and 40 kHz. Depending on signal type, as well as recording aspect and distance to the hydrophone, these peaks varied in relative amplitude. The description of Baird's echolocation signals will allow for studies of their distribution and abundance using towed array data without associated visual sightings and from autonomous seafloor hydrophones.

Coverage by land, sea, and airplane surveys, 1900-1967.

NASA Technical Reports Server (NTRS)

Fabiano, E.; Cain, S. J.

1971-01-01

The worldwide coverage of the earth by land, sea, and aircraft magnetic surveys since the beginning of the 20th century is shown on three world maps for surface surveys spanning the periods of 1900-1930, 1930-1955, and 1955-1967, respectively, on a fourth map for ship-towed magnetometer surveys performed after 1956, and on a fifth map for 1953-1966 airborne survey data. The technique used, involving a position plotting of each measurement with a microfilm plotter, results in the appearance of heavily surveyed regions as completely darkened areas. The coverage includes measurements at about 100,000 land stations, airborne measurements at over 90,000 points, and marine measurements at over 25,000 points. The marine measurements cover over 1,000,000 km of trackline.

Standardized UXO Technology Demonstration Site Blind Grid Record No. 904 (Sky Research, Inc.). EM61 MKII/Towed Array

DTIC Science & Technology

2008-09-01

DEMONSTRATOR’S FIELD PERSONNEL Geophysicist: Craig Hyslop Geophysicist: John Jacobsen Geophysicist: Rob Mehl 3.7 DEMONSTRATOR’S FIELD SURVEYING...Yuma Proving Ground Soil Survey Report, May 2003. 5. Practical Nonparametric Statistics, W.J. Conover, John Wiley & Sons, 1980 , pages 144 through

Detection and Discrimination in One Pass Using the OPTEMA Towed Array

DTIC Science & Technology

2017-02-21

classification survey was performed using the One Pass Time domain EM Array (OPTEMA) at the former Southwestern Proving Ground near Hope, AR. Over...small arms ammunition, 20 to 155 mm projectiles, mortars, rockets, grenades, and up to 500-lb bombs [7]. Following the end of World War II, the proving...Range summary report [5]. It is assumed that combined field survey and analysis rates of $1000/acre for an EM -61 DGM survey and $30/anomaly for a

Large-scale magnetic field perturbation arising from the 18 May 1980 eruption from Mount St. Helens, Washington

USGS Publications Warehouse

Mueller, R.J.; Johnston, M.J.S.

1989-01-01

A traveling magnetic field disturbance generated by the 18 may 1980 eruption of Mount St. Helens at 1532 UT was detected on an 800-km linear array of recording magnetometers installed along the San Andreas fault system in California, from San Francisco to the Salton Sea. Arrival times of the disturbance field, from the most northern of these 24 magnetometers (996 km south of the volcano) to the most southern (1493 km S23?? E), are consistent with the generation of a traveling ionospheric disturbance stimulated by the blast pressure wave in the atmosphere. The first arrivals at the north and the south ends of the array occurred at 26 and 48 min, respectively, after the initial eruption. Apparent average wave velocity through the array is 309 ?? 14 m s-1 but may have approached 600 m s-1 close to the volcano. The horizontal phase and the group velocity of ??? 300 m s-1 at periods of 70-80 min, and the attenuation with distance, strongly suggest that the magnetic field perturbations at distances of 1000-1500 km are caused by gravity mode acoustic-gravity waves propagating at F-region heights in the ionosphere. ?? 1989.

ULTIMA: Array of ground-based magnetometer arrays for monitoring magnetospheric and ionospheric perturbations on a global scale

NASA Astrophysics Data System (ADS)

Yumoto, K.; Chi, P. J.; Angelopoulos, V.; Connors, M. G.; Engebretson, M. J.; Fraser, B. J.; Mann, I. R.; Milling, D. K.; Moldwin, M. B.; Russell, C. T.; Stolle, C.; Tanskanen, E.; Vallante, M.; Yizengaw, E.; Zesta, E.

2012-12-01

ULTIMA (Ultra Large Terrestrial International Magnetic Array) is an international consortium that aims at promoting collaborative research on the magnetosphere, ionosphere, and upper atmosphere through the use of ground-based magnetic field observatories. ULTIMA is joined by individual magnetometer arrays in different countries/regions, and the current regular-member arrays are Australian, AUTUMN, CARISMA, DTU Space, Falcon, IGPP-LANL, IMAGE, MACCS, MAGDAS, McMAC, MEASURE, THEMIS, and SAMBA. The Chair of ULTIMA has been K. Yumoto (MAGDAS), and its Secretary has been P. Chi (McMAC, Falcon). In this paper we perform case studies in which we estimate the global patterns of (1) near-Earth currents and (2) magnetic pulsations; these phenomena are observed over wide areas on the ground, thus suitable for the aims of ULTIMA. We analyze these two phenomena during (a) quiet period and (b) magnetic storm period. We compare the differences between these two periods by drawing the global maps of the ionospheric equivalent currents (which include the effects of all the near-Earth currents) and pulsation amplitudes. For ionospheric Sq currents at low latitudes during quiet periods, MAGDAS data covering an entire solar cycle has yielded a detailed statistical model, and we can use it as a reference for the aforementioned comparison. We also estimate the azimuthal wave numbers of pulsations and compare the amplitude distribution of pulsations with the distribution of highly energetic (in MeV range) particles simultaneously observed at geosynchronous satellites.

Geospace Science from Ground-based Magnetometer Arrays: Advances in Sensors, Data Collection, and Data Integration

NASA Astrophysics Data System (ADS)

Mann, Ian; Chi, Peter

2016-07-01

Networks of ground-based magnetometers now provide the basis for the diagnosis of magnetic disturbances associated with solar wind-magnetosphere-ionosphere coupling on a truly global scale. Advances in sensor and digitisation technologies offer increases in sensitivity in fluxgate, induction coil, and new micro-sensor technologies - including the promise of hybrid sensors. Similarly, advances in remote connectivity provide the capacity for truly real-time monitoring of global dynamics at cadences sufficient for monitoring and in many cases resolving system level spatio-temporal ambiguities especially in combination with conjugate satellite measurements. A wide variety of the plasmaphysical processes active in driving geospace dynamics can be monitored based on the response of the electrical current system, including those associated with changes in global convection, magnetospheric substorms and nightside tail flows, as well as due to solar wind changes in both dynamic pressure and in response to rotations of the direction of the IMF. Significantly, any changes to the dynamical system must be communicated by the propagation of long-period Alfven and/or compressional waves. These wave populations hence provide diagnostics for not only the energy transport by the wave fields themselves, but also provide a mechanism for diagnosing the structure of the background plasma medium through which the waves propagate. Ultra-low frequency (ULF) waves are especially significant in offering a monitor for mass density profiles, often invisible to particle detectors because of their very low energy, through the application of a variety of magneto-seismology and cross-phase techniques. Renewed scientific interest in the plasma waves associated with near-Earth substorm dynamics, including magnetosphere-ionosphere coupling at substorm onset and their relation to magnetotail flows, as well the importance of global scale ultra-low frequency waves for the energisation, transport, acceleration, and loss of electrons in the radiation belts promise high profile science returns. Integrated, global scale data products also have potential importance and application for real-time monitoring of the space weather threats to electrical power grids from geomagnetically induced currents. Such data exploitation increasingly relies on the collaborations between multiple national magnetometer arrays to generate single data products with common file format and data properties. We review advances in geospace science which can be delivered by networks of ground-based magnetometers - in terms of advances in sensors, data collection, and data integration - including through collaborations within the Ultra-Large Terrestrial International Magnetometer Array (ULTIMA) consortium.

Development of Deep-tow Autonomous Cable Seismic (ACS) for Seafloor Massive Sulfides (SMSs) Exploration.

NASA Astrophysics Data System (ADS)

Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hitoshi; Saito, Shutaro; Lee, Sangkyun; Tara, Kenji; Kato, Masafumi; Jamali Hondori, Ehsan; Sumi, Tomonori; Kadoshima, Kazuyuki; Kose, Masami

2017-04-01

Within the EEZ of Japan, numerous surveys exploring ocean floor resources have been conducted. The exploration targets are gas hydrates, mineral resources (manganese, cobalt or rare earth) and especially seafloor massive sulphide (SMS) deposits. These resources exist in shallow subsurface areas in deep waters (>1500m). For seismic explorations very high resolution images are required. These cannot be effectively obtained with conventional marine seismic techniques. Therefore we have been developing autonomous seismic survey systems which record the data close to the seafloor to preserve high frequency seismic energy. Very high sampling rate (10kHz) and high accurate synchronization between recording systems and shot time are necessary. We adopted Cs-base atomic clock considering its power consumption. At first, we developed a Vertical Cable Seismic (VCS) system that uses hydrophone arrays moored vertically from the ocean bottom to record close to the target area. This system has been successfully applied to SMS exploration. Specifically it fixed over known sites to assess the amount of reserves with the resultant 3D volume. Based on the success of VCS, we modified the VCS system to use as a more efficient deep-tow seismic survey system. Although there are other examples of deep-tow seismic systems, signal transmission cables present challenges in deep waters. We use our autonomous recording system to avoid these problems. Combining a high frequency piezoelectric source (Sub Bottom Profiler:SBP) that automatically shots with a constant interval, we achieve the high resolution deep-tow seismic without data transmission/power cable to the board. Although the data cannot be monitored in real-time, the towing system becomes very simple. We have carried out survey trial, which showed the systems utility as a high-resolution deep-tow seismic survey system. Furthermore, the frequency ranges of deep-towed source (SBP) and surface towed sparker are 700-2300Hz and 10-200Hz respectively. Therefore we can use these sources simultaneously and distinguish the records of each source in the data processing stage. We have developed new marine seismic survey systems with autonomous recording for the exploration of the ocean floor resources. The applications are vertical cable seismic (VCS) and deep-tow seismic (ACS). These enable us the recording close to the seafloor and give the high resolution results with a simple, cost-effective configuration.

Four-channel optically pumped atomic magnetometer for magnetoencephalography

PubMed Central

Colombo, Anthony P.; Carter, Tony R.; Borna, Amir; Jau, Yuan-Yu; Johnson, Cort N.; Dagel, Amber L.; Schwindt, Peter D. D.

2016-01-01

We have developed a four-channel optically pumped atomic magnetometer for magnetoencephalography (MEG) that incorporates a passive diffractive optical element (DOE). The DOE allows us to achieve a long, 18-mm gradiometer baseline in a compact footprint on the head. Using gradiometry, the sensitivities of the channels are < 5 fT/Hz1/2, and the 3-dB bandwidths are approximately 90 Hz, which are both sufficient to perform MEG. Additionally, the channels are highly uniform, which offers the possibility of employing standard MEG post-processing techniques. This module will serve as a building block of an array for magnetic source localization. PMID:27410816

Four-channel optically pumped atomic magnetometer for magnetoencephalography

DOE PAGES

Colombo, Anthony P.; Carter, Tony R.; Borna, Amir; ...

2016-06-29

We have developed a four-channel optically pumped atomic magnetometer for magnetoencephalography (MEG) that incorporates a passive diffractive optical element (DOE). The DOE allows us to achieve a long, 18-mm gradiometer baseline in a compact footprint on the head. Using gradiometry, the sensitivities of the channels are < 5 fT/Hz 1/2, and the 3-dB bandwidths are approximately 90 Hz, which are both sufficient to perform MEG. Additionally, the channels are highly uniform, which offers the possibility of employing standard MEG post-processing techniques. As a result, this module will serve as a building block of an array for magnetic source localization.

Remote sensing the plasmasphere, plasmapause, plumes and other features using ground-based magnetometers

NASA Astrophysics Data System (ADS)

Menk, Frederick; Kale, Zoë; Sciffer, Murray; Robinson, Peter; Waters, Colin; Grew, Russell; Clilverd, Mark; Mann, Ian

2014-11-01

The plasmapause is a highly dynamic boundary between different magnetospheric particle populations and convection regimes. Some of the most important space weather processes involve wave-particle interactions in this region, but wave properties may also be used to remote sense the plasmasphere and plasmapause, contributing to plasmasphere models. This paper discusses the use of existing ground magnetometer arrays for such remote sensing. Using case studies we illustrate measurement of plasmapause location, shape and movement during storms; refilling of flux tubes within and outside the plasmasphere; storm-time increase in heavy ion concentration near the plasmapause; and detection and mapping of density irregularities near the plasmapause, including drainage plumes, biteouts and bulges. We also use a 2D MHD model of wave propagation through the magnetosphere, incorporating a realistic ionosphere boundary and Alfvén speed profile, to simulate ground array observations of power and cross-phase spectra, hence confirming the signatures of plumes and other density structures.

A small towed beamforming array to identify vocalizing resident killer whales ( Orcinus orca) concurrent with focal behavioral observations

NASA Astrophysics Data System (ADS)

Miller, Patrick J.; Tyack, Peter L.

Investigations of communication systems benefit from concurrent observation of vocal and visible behaviors of individual animals. A device has been developed to identify individual vocalizing resident killer whales ( Orcinus orca) during focal behavioral observations. The device consists of a 2-m, 15-element hydrophone array, which is easily towed behind a small vessel, on-board multi-channel recorders, and real-time signal processing equipment. Acoustic data from the hydrophones are digitized and processed using broadband frequency-domain beamforming to yield frequency-azimuth (FRAZ) and "directo-gram" displays of arriving sounds. Based upon statistical analysis of independent portions of typical killer whale calls, the precision of the angle-of-arrival estimate ranges from ±0° to ±2.5° with a mean precision of ±1.5°. Echolocation clicks also are resolved precisely with a typical -6 dB mainlobe width of ±2.0°. Careful positioning of the array relative to the animals minimizes the effects of depth ambiguities and allows identification of individual sources in many circumstances. Several strategies for identifying vocalizing individuals are discussed and an example of a successful identification is described. Use of the array with resident killer whales did not interfere with vessel maneuverability, animal tracking, or behavioral sampling of focal individuals. This localization technique has promise for advancing the abilities of researchers to conduct unbiased behavioral and acoustic sampling of individual free-ranging cetaceans.

First high-resolution near-seafloor survey of magnetic anomalies of the South China Sea

NASA Astrophysics Data System (ADS)

Lin, J.; Xu, X.; Li, C.; Sun, Z.; Zhu, J.; Zhou, Z.; Qiu, N.

2013-12-01

We successfully conducted the first high-resolution near-seafloor magnetic survey of the Central, Southwest, and Northern Central Basins of the South China Sea (SCS) during two cruises on board Chinese R/V HaiYangLiuHao in October-November 2012 and March-April 2013, respectively. Measurements of magnetic field were made along four long survey lines, including (1) a NW-SE across-isochron profile transecting the Southwest Basin and covering all ages of the oceanic crust (Line CD); (2) a N-S across-isochron profile transecting the Central Basin (Line AB); and (3) two sub-parallel NE-SW across-isochron profiles transecting the Northern Central Basin of the SCS (Lines D and E). A three-axis magnetometer was mounted on a deep-tow vehicle, flying within 0.6 km above the seafloor. The position of the tow vehicle was provided by an ultra-short baseline navigation system along Lines D and E, while was estimated using shipboard GPS along Lines AB and CD. To investigate crustal magnetization, we first removed the International Geomagnetic Reference Field (IGRF) of 2010 from the measured magnetic data, and then downward continued the resultant magnetic field data to a horizontal plane at a water depth of 4.5 km to correct for variation due to the fishing depth of the deep-tow vehicle. Finally, we calculated magnetic anomalies at various water depths after reduction-to-the-pole corrections. We also constructed polarity reversal block (PRB) models of crustal magnetization by matching peaks and troughs of the observed magnetic field anomaly. Our analysis yielded the following results: (1) The near-bottom magnetic anomaly showed peak-to-trough amplitudes of more than 2,500 nT, which are several times of the anomaly amplitudes at the sea surface, illustrating that deep-tow measurements acquired much higher spatial resolutions. (2) The deep-tow data revealed several distinctive magnetic anomalies with wavelengths of 5-15 km and amplitudes of several hundred nT. These short-wavelength anomalies were unrecognized in sea surface measurements. (3) Preliminary results showed that the study regions might have experienced several episodes of magnetic reversal events that were not recognized in existing models. (4) We are currently investigating the geomagnetic timing of these relatively short-duration events to determine the detailed spreading history of the sub-basins of the SCS. These high-resolution near-seafloor magnetic survey lines are located close to the planned drilling sites of IODP Expedition 349 scheduled for January-March 2014.

15 CFR Supplement No. 7 to Part 774 - Very Sensitive List

Code of Federal Regulations, 2014 CFR

2014-01-01

... designed” for real time application with towed acoustic hydrophone arrays, having “user accessible....2.f—Processing equipment, “specially designed” for real time application with bottom or bay cable...” “specially designed” for a defense article not on the USML or a commodity controlled by a “600 series” ECCN...

Standardized UXO Technology Demonstration Site Open Field Scoring Record No. 905 (Sky Research, Inc.) EM61 MKII/Towed Array

DTIC Science & Technology

2008-09-01

day timeframe. 3.6 DEMONSTRATOR’S FIELD PERSONNEL Geophysicist: Craig Hyslop Geophysicist: John Jacobsen Geophysicist: Rob Mehl 3.7...Practical Nonparametric Statistics, W.J. Conover, John Wiley & Sons, 1980 , pages 144 through 151. F-1 (Page F-2 Blank) APPENDIX F

Safety System for a Towed Array

DTIC Science & Technology

2017-09-25

to a loss of life. [0006] The present way to prevent this failure involves the use of a handling system with a rated load that is higher than the...IN REPLY REFER TO Attorney Docket No . 300196 20...Technology Transfer at (401) 832-1511. DISTRIBUTION STATEMENT Approved for Public Release Distribution is unlimited Attorney Docket No

UXO Detection and Characterization in the Marine Environment

DTIC Science & Technology

2008-11-01

65 APPENDIX B – NAD Puget Sound Historical Documents ............................................CD APPENDIX C...16 18. A part of Ostrich Bay adjacent to the Naval Ammunition Depot Puget Sound is shown during...viii EXECUTIVE SUMMARY The second demonstration of the Marine Towed Array took place June 12-30, 2006 on Ostrich Bay ( Puget Sound ) in the state

3D forward modeling and response analysis for marine CSEMs towed by two ships

NASA Astrophysics Data System (ADS)

Zhang, Bo; Yin, Chang-Chun; Liu, Yun-He; Ren, Xiu-Yan; Qi, Yan-Fu; Cai, Jing

2018-03-01

A dual-ship-towed marine electromagnetic (EM) system is a new marine exploration technology recently being developed in China. Compared with traditional marine EM systems, the new system tows the transmitters and receivers using two ships, rendering it unnecessary to position EM receivers at the seafloor in advance. This makes the system more flexible, allowing for different configurations (e.g., in-line, broadside, and azimuthal and concentric scanning) that can produce more detailed underwater structural information. We develop a three-dimensional goal-oriented adaptive forward modeling method for the new marine EM system and analyze the responses for four survey configurations. Oceanbottom topography has a strong effect on the marine EM responses; thus, we develop a forward modeling algorithm based on the finite-element method and unstructured grids. To satisfy the requirements for modeling the moving transmitters of a dual-ship-towed EM system, we use a single mesh for each of the transmitter locations. This mitigates the mesh complexity by refining the grids near the transmitters and minimizes the computational cost. To generate a rational mesh while maintaining the accuracy for single transmitter, we develop a goal-oriented adaptive method with separate mesh refinements for areas around the transmitting source and those far away. To test the modeling algorithm and accuracy, we compare the EM responses calculated by the proposed algorithm and semi-analytical results and from published sources. Furthermore, by analyzing the EM responses for four survey configurations, we are confirm that compared with traditional marine EM systems with only in-line array, a dual-ship-towed marine system can collect more data.

Improving the Performance of MEMS GYROS via Redundant Measurements: Theory and Experiments

DTIC Science & Technology

2014-12-01

gyroscope arrays, improve performance inertial measurement unit ( IMU ), Sparkfun razor IMU , gyroscope, magnetometer, accelerometer, redundant IMU , angular...30 Figure 15 Sparkfun 9DOF razor IMU , after [21...43 Figure 27 Sparkfun razor IMU (bottom) connected to the FT232R breakout board (top) and then to a

Measurement of High Reynolds Number Stratified Turbulent Wake of a Towed Sphere

NASA Astrophysics Data System (ADS)

Brandt, Alan; Kalumuck, Kenneth

2017-11-01

Although aircraft and ships operate at Reynolds numbers significantly greater than one million, there are virtually no extant data on the turbulence of wakes at Re >106, above the drag crisis regime. The present study is designed to characterize the near-field of a stratified wake at large Reynolds numbers, Re 2 x 105 - 106, by towing a large diameter (D 0.5 m) sphere through a thermally stratified fresh water lake and a thermally stratified large salt water towing tank. Stratification produced BV frequencies, N, up to 0.07 s-1 resulting in Froude numbers F = U/ND >= 15. Three component turbulent velocities and temperature measurements were obtained using Acoustic Doppler Velocimeters (ADVs) and an array of fast response thermistors at various downstream distances. Turbulence power spectra of both the velocity and temperature signals exhibited a clear -5/3 slope over an order-of-magnitude range in wavenumber, which is generally not clearly evident in lower Re laboratory experiments. This study is sponsored by the Office of Naval Research Turbulence and Stratified Wakes Program.

Summary of Activities for Health Monitoring of Composite Overwrapped Pressure Vessels

NASA Technical Reports Server (NTRS)

Russell, Rick

2012-01-01

This new start project (FY12-14) will design and demonstrate the ability of nondestructive evaluation sensors for the measurement of stresses on the inner diameter of a Composite Overwrapped Pressure Vessel overwrap. Results will be correlated with other nondestructive evaluation technologies such as Acoustic Emission. The project will build upon a proof of concept study performed at KSC which demonstrated the ability of Magnetic Stress Gages to measure stresses at internal overwraps and upon current acoustic emission research being performed at WSTF; The gages will be produced utilizing Maundering Winding Magnetometer and/or Maundering Winding Magnetometer-array eddy current technology. The proof-of-concept study demonstrated a correlation between the sensor response and pressure or strain. The study also demonstrated the ability of Maundering Winding Magnetometer technology to monitor the stresses in a Composite Overwrapped Pressure Vessel at different orientations and depths. The ultimate goal is to utilize this technology for the health monitoring of Composite Overwrapped Pressure Vessels for all future flight programs.

Multi-flux-transformer MRI detection with an atomic magnetometer.

PubMed

Savukov, Igor; Karaulanov, Todor

2014-12-01

Recently, anatomical ultra-low field (ULF) MRI has been demonstrated with an atomic magnetometer (AM). A flux-transformer (FT) has been used for decoupling MRI fields and gradients to avoid their negative effects on AM performance. The field of view (FOV) was limited because of the need to compromise between the size of the FT input coil and MRI sensitivity per voxel. Multi-channel acquisition is a well-known solution to increase FOV without significantly reducing sensitivity. In this paper, we demonstrate twofold FOV increase with the use of three FT input coils. We also show that it is possible to use a single atomic magnetometer and single acquisition channel to acquire three independent MRI signals by applying a frequency-encoding gradient along the direction of the detection array span. The approach can be generalized to more channels and can be critical for imaging applications of non-cryogenic ULF MRI where FOV needs to be large, including head, hand, spine, and whole-body imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

Multi-flux-transformer MRI detection with an atomic magnetometer

PubMed Central

Savukov, Igor; Karaulanov, Todor

2014-01-01

Recently, anatomical ultra-low field (ULF) MRI has been demonstrated with an atomic magnetometer (AM). A flux-transformer (FT) has been used for decoupling MRI fields and gradients to avoid their negative effects on AM performance. The field of view (FOV) was limited because of the need to compromise between the size of the FT input coil and MRI sensitivity per voxel. Multi-channel acquisition is a well-known solution to increase FOV without significantly reducing sensitivity. In this paper, we demonstrate two-fold FOV increase with the use of three FT input coils. We also show that it is possible to use a single atomic magnetometer and single acquisition channel to acquire three independent MRI signals by applying a frequency-encoding gradient along the direction of the detection array span. The approach can be generalized to more channels and can be critical for imaging applications of non-cryogenic ULF MRI where FOV needs to be large, including head, hand, spine, and whole-body imaging. PMID:25462946

Abandoned underground storage tank location using fluxgate magnetic surveying: A case study

USGS Publications Warehouse

Van Biersel, T. P.; Bristoll, B.C.; Taylor, R.W.; Rose, J.

2002-01-01

In 1993, during the removal of a diesel and a gasoline underground storage tank at the municipal garage of the Village of Kohler, Sheboygan County, Wisconsin, soil testing revealed environmental contamination at the site. A site investigation revealed the possibility of a second on-site source of petroleum contamination. Limited historical data and the present usage of structures within the suspected source area precluded the use of most invasive sampling methods and most geophysical techniques. A fluxgate magnetometer survey, followed by confirmatory excavation, was conducted at the site. The fluxgate magnetometer survey identified nine possible magnetic anomalies within the 18 ?? 25 m area. The subsequent excavation near the anomalies revealed the presence of five paired and two individual 2000 L underground storage tanks. The fluxgate magnetometer survey, although affected by the proximity of buildings, was able to detect the buried tanks within 3 m of the brick structures, using a 1.5 ?? 1.5 m sampling array.

Three axis vector atomic magnetometer utilizing polarimetric technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com

2016-09-15

The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity fieldmore » gradient measurement as required for biomedical application.« less

50 CFR 218.34 - Requirements for monitoring and reporting.

Code of Federal Regulations, 2013 CFR

2013-10-01

... beyond the border of the exclusion zone (i.e., the circumference of the area from the border of the... (hydrophone or towed array) could be used to determine if marine mammals are in the area before and/or after a... participation shall take into account safety, logistics, and operational concerns. (iv) MMOs shall observe from...

50 CFR 218.34 - Requirements for monitoring and reporting.

Code of Federal Regulations, 2012 CFR

2012-10-01

... beyond the border of the exclusion zone (i.e., the circumference of the area from the border of the... (hydrophone or towed array) could be used to determine if marine mammals are in the area before and/or after a... participation shall take into account safety, logistics, and operational concerns. (iv) MMOs shall observe from...

50 CFR 218.34 - Requirements for monitoring and reporting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... beyond the border of the exclusion zone (i.e., the circumference of the area from the border of the... (hydrophone or towed array) could be used to determine if marine mammals are in the area before and/or after a... participation shall take into account safety, logistics, and operational concerns. (iv) MMOs shall observe from...

Low-Frequency Reverberation Measurements with an Activated Towed Array: Scattering Strengths and Statistics,

DTIC Science & Technology

1987-10-01

8 dB per bounce (at 370 Hz), which are in good agreement with acoustic reflectivity measurements made in the same areas ( Hastrup and Akal (271). 5.3...SACLANTCEN, held June 10-14, 1985, Lerici, Italy. New York, NY, Plenum, 1986: pp. 355-364. [27] HASTRUP , O.F. and AKAL, T. Acoustic reflectivity

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary

NASA Astrophysics Data System (ADS)

Weygand, J. M.; Wing, S.

2016-06-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2°±1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data.

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary✩

PubMed Central

Weygand, J.M.; Wing, S.

2017-01-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2° ± 1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data. PMID:29056861

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary.

PubMed

Weygand, J M; Wing, S

2016-06-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2° ± 1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data.

Observations by Mid-continent Magnetoseismic Chain (McMAC) and their use in space weather research

NASA Astrophysics Data System (ADS)

Chi, P. J.; McMac Team

The Mid-continent Magnetoseismic Chain McMAC consists of nine magnetometer stations that line up across the U S and Mexico along the 330th magnetic meridian These systems sample at 2 Hz and monitor the fluctuations of the geomagnetic field caused by space weather phenomena and they are always on the Internet to allow rapid access of data The McMAC stations can connect to the Fort Churchill Line of the CARISMA Array and two IGPP-LANL stations at the same longitude and form a long magnetometer chain that spans the L-value range from 1 3 to 11 7 the greatest latitudinal coverage in all meridians One of the main advantages of this magnetometer chain is its close separation between adjacent stations enabling the use of the gradient technique to identify field line resonance FLR frequencies and to further estimate the plasma mass density in the magnetosphere The observations of FLR and the derived density can always be collected in the daytime and occasionally in the nighttime as well In this paper we present the observations by the newly completed McMAC and jointly by the CARISMA and IGPP-LANL Arrays The observed plasma density and its wide coverage in L-value can benefit space weather studies such as on magnetosphere-ionosphere coupling and on the wave-particle interaction for modeling the radiation belts Also discussed are other applications of the McMAC observations in space weather research including possible joint observations with satellite missions

A Near-real-time Data Transport System for Selected Stations in the Magnetometer Array for Cusp and Cleft Studies (MACCS)

NASA Astrophysics Data System (ADS)

Engebretson, M. J.; Valentic, T. A.; Stehle, R. H.; Hughes, W. J.

2004-05-01

The Magnetometer Array for Cusp and Cleft Studies (MACCS) is a two-dimensional array of eight fluxgate magnetometers that was established in 1992-1993 in the Eastern Canadian Arctic from 75° to over 80° MLAT to study electrodynamic interactions between the solar wind and Earth's magnetosphere and high-latitude ionosphere. A ninth site in Nain, Labrador, extends coverage down to 66° between existing Canadian and Greenland stations. Originally designed as part of NSF's GEM (Geospace Environment Modeling) Program, MACCS has contributed to the study of transients and waves at the magnetospheric boundary and in the near-cusp region as well as to large, cooperative, studies of ionospheric convection and substorm processes. Because of the limitations of existing telephone lines to each site, it has not been possible to economically access MACCS data promptly; instead, each month's collected data is recorded and mailed to the U.S. for processing and eventual posting on a publicly-accessible web site, http://space.augsburg.edu/space. As part of its recently renewed funding, NSF has supported the development of a near-real-time data transport system using the Iridium satellite network, which will be implemented at two MACCS sites in summer 2004. At the core of the new MACCS communications system is the Data Transport Network, software developed with NSF-ITR funding to automate the transfer of scientific data from remote field stations over unreliable, bandwidth-constrained network connections. The system utilizes a store-and-forward architecture based on sending data files as attachments to Usenet messages. This scheme not only isolates the instruments from network outages, but also provides a consistent framework for organizing and accessing multiple data feeds. Client programs are able to subscribe to data feeds to perform tasks such as system health monitoring, data processing, web page updates and e-mail alerts. The MACCS sites will employ the Data Transport Network on a small local Linux-based computer connected to an Iridium transceiver. Between 3-5Mb of data a day will be collected from the magnetometers and delivered in near-real-time for automatic distribution to modelers and index developers. More information about the Data Transport Network can be found at http://transport.sri.com/TransportDevel .

Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

NASA Astrophysics Data System (ADS)

Yizengaw, E.; Moldwin, M.; Zesta, E.

2015-12-01

The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the American sector and weaker in the African sector - why are the occurrence and amplitude of equatorial irregularities stronger in the African sector?

Vulnerability Analysis of an All-Electric Warship

DTIC Science & Technology

2010-06-01

active. Damage Control: Fire fighting, dewatering, lighting, electrical receptacles (for powering damage control equipment such as submersible pumps ...sufficient radar not available. This also requires an increase in chill water capacity by adding pump , compressor, and ASW pump . Remaining ventilation systems...Activate towed-array sonar, if applicable. Increase speed to 25 knots. Non-Vital Loads: All non-vital loads. Examples include galley equipment, heat

BabyMEG: A whole-head pediatric magnetoencephalography system for human brain development research

NASA Astrophysics Data System (ADS)

Okada, Yoshio; Hämäläinen, Matti; Pratt, Kevin; Mascarenas, Anthony; Miller, Paul; Han, Menglai; Robles, Jose; Cavallini, Anders; Power, Bill; Sieng, Kosal; Sun, Limin; Lew, Seok; Doshi, Chiran; Ahtam, Banu; Dinh, Christoph; Esch, Lorenz; Grant, Ellen; Nummenmaa, Aapo; Paulson, Douglas

2016-09-01

We developed a 375-channel, whole-head magnetoencephalography (MEG) system ("BabyMEG") for studying the electrophysiological development of human brain during the first years of life. The helmet accommodates heads up to 95% of 36-month old boys in the USA. The unique two-layer sensor array consists of: (1) 270 magnetometers (10 mm diameter, ˜15 mm coil-to-coil spacing) in the inner layer, (2) thirty-five three-axis magnetometers (20 mm × 20 mm) in the outer layer 4 cm away from the inner layer. Additionally, there are three three-axis reference magnetometers. With the help of a remotely operated position adjustment mechanism, the sensor array can be positioned to provide a uniform short spacing (mean 8.5 mm) between the sensor array and room temperature surface of the dewar. The sensors are connected to superconducting quantum interference devices (SQUIDs) operating at 4.2 K with median sensitivity levels of 7.5 fT/√Hz for the inner and 4 fT/√Hz for the outer layer sensors. SQUID outputs are digitized by a 24-bit acquisition system. A closed-cycle helium recycler provides maintenance-free continuous operation, eliminating the need for helium, with no interruption needed during MEG measurements. BabyMEG with the recycler has been fully operational from March, 2015. Ongoing spontaneous brain activity can be monitored in real time without interference from external magnetic noise sources including the recycler, using a combination of a lightly shielded two-layer magnetically shielded room, an external active shielding, a signal-space projection method, and a synthetic gradiometer approach. Evoked responses in the cortex can be clearly detected without averaging. These new design features and capabilities represent several advances in MEG, increasing the utility of this technique in basic neuroscience as well as in clinical research and patient studies.

BabyMEG: A whole-head pediatric magnetoencephalography system for human brain development research.

PubMed

Okada, Yoshio; Hämäläinen, Matti; Pratt, Kevin; Mascarenas, Anthony; Miller, Paul; Han, Menglai; Robles, Jose; Cavallini, Anders; Power, Bill; Sieng, Kosal; Sun, Limin; Lew, Seok; Doshi, Chiran; Ahtam, Banu; Dinh, Christoph; Esch, Lorenz; Grant, Ellen; Nummenmaa, Aapo; Paulson, Douglas

2016-09-01

We developed a 375-channel, whole-head magnetoencephalography (MEG) system ("BabyMEG") for studying the electrophysiological development of human brain during the first years of life. The helmet accommodates heads up to 95% of 36-month old boys in the USA. The unique two-layer sensor array consists of: (1) 270 magnetometers (10 mm diameter, ∼15 mm coil-to-coil spacing) in the inner layer, (2) thirty-five three-axis magnetometers (20 mm × 20 mm) in the outer layer 4 cm away from the inner layer. Additionally, there are three three-axis reference magnetometers. With the help of a remotely operated position adjustment mechanism, the sensor array can be positioned to provide a uniform short spacing (mean 8.5 mm) between the sensor array and room temperature surface of the dewar. The sensors are connected to superconducting quantum interference devices (SQUIDs) operating at 4.2 K with median sensitivity levels of 7.5 fT/√Hz for the inner and 4 fT/√Hz for the outer layer sensors. SQUID outputs are digitized by a 24-bit acquisition system. A closed-cycle helium recycler provides maintenance-free continuous operation, eliminating the need for helium, with no interruption needed during MEG measurements. BabyMEG with the recycler has been fully operational from March, 2015. Ongoing spontaneous brain activity can be monitored in real time without interference from external magnetic noise sources including the recycler, using a combination of a lightly shielded two-layer magnetically shielded room, an external active shielding, a signal-space projection method, and a synthetic gradiometer approach. Evoked responses in the cortex can be clearly detected without averaging. These new design features and capabilities represent several advances in MEG, increasing the utility of this technique in basic neuroscience as well as in clinical research and patient studies.

Characterization of archaeological structures using the magnetic method in Thaje archaeological site, Saudi Arabia

NASA Astrophysics Data System (ADS)

Alkhatib Alkontar, Rozan; Calou, Paul; Rohmer, Jérôme; Munschy, Marc

2017-04-01

Among the surface methods of exploration that have been developed to meet the new requirements of archaeological research, geophysical methods offer a wide range of applications in the study of buried deposits. As a result of the most recent development, the magnetic field- prospection method is very efficient to highlight buried foundations even if the corresponding construction material is weakly magnetized like, for example, limestone. The magnetic field, that is being measured in a specific place and at a specific time, is the vector sum of the main regional magnetic field, the effect of subsurface structures, the temporal variation (mainly solar influence) and local disturbances such as power lines, buildings, fences … The measurement method is implemented by using an array of fluxgate 3-components magnetometers carried 1 m above the floor. The advantage of using vector magnetometers is that magnetic compensation can be of achieved. An array of four magnetometers are used to survey the archaeological site of Thaje (100-300 yr BC), Saudi Arabia, and to obtain a precise location of measurements, a differential global navigation satellite system is used with an accuracy of about 10 cm relative to the base station. 25 hectares have been surveyed within 13 days and data are compile to obtain a total magnetic intensity map with a node spacing of 25 cm. The map is interpreted using magnetic field transforms, such as reduction to the pole, fractional vertical derivatives. Tilt-angle. The results show a fairly precise plan of the city where main streets, buildings and rampart can be clearly distinguished.

Performance of a novel SQUID-based superconducting imaging-surface magnetoencephalography system

NASA Astrophysics Data System (ADS)

Kraus, R. H.; Volegov, P.; Maharajh, K.; Espy, M. A.; Matlashov, A. N.; Flynn, E. R.

2002-03-01

Performance for a recently completed whole-head magnetoencephalography system using a superconducting imaging surface (SIS) surrounding an array of 150 SQUID magnetometers is reported. The helmet-like SIS is hemispherical in shape with a brim. Conceptually, the SIS images nearby sources onto the SQUIDs while shielding sensors from distant “noise” sources. A finite element method (FEM) description using the as-built geometry was developed to describe the SIS effect on source fields by imposing B⊥( surface)=0 . Sensors consist of 8×8 mm 2 SQUID magnetometers with 0.84 nT/ Φ0 sensitivity and <3 fT/ Hz noise. A series of phantom experiments to verify system efficacy have been completed. Simple dry-wire phantoms were used to eliminate model dependence from our results. Phantom coils were distributed throughout the volume encompassed by the array with a variety of orientations. Each phantom coil was precisely machined and located to better than 25 μm and 10 mRad accuracy. Excellent agreement between model-calculated and measured magnetic field distributions of all phantom coil positions and orientations was found. Good agreement was found between modeled and measured shielding of the SQUIDs from sources external to the array showing significant frequency-independent shielding. Phantom localization precision was better than 0.5 mm at all locations with a mean of better than 0.3 mm.

CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: The effect of substrate on magnetic properties of Co/Cu multilayer nanowire arrays

NASA Astrophysics Data System (ADS)

Ren, Yong; Wang, Jian-Bo; Liu, Qing-Fang; Han, Xiang-Hua; Xue, De-Sheng

2009-08-01

Ordered Co/Cu multilayer nanowire arrays have been fabricated into anodic aluminium oxide templates with Ag and Cu substrate by direct current electrodeposition. This paper studies the morphology, structure and magnetic properties by transmission electron microscopy, selective area electron diffraction, x-ray diffraction, and vibrating sample magnetometer. X-ray diffraction patterns reveal that both as-deposited nanowire arrays films exhibit face-centred cubic structure. Magnetic measurements indicate that the easy magnetization direction of Co/Cu multilayer nanowire arrays films on Ag substrate is perpendicular to the long axis of nanowire, whereas the easy magnetization direction of the sample with Cu substrate is parallel to the long axis of nanowire. The change of easy magnetization direction attributed to different substrates, and the magnetic properties of the nanowire arrays are discussed.

Magnetic observations at Geophysical Observatory Paratunka IKIR FEB RAS: tasks, possibilities and future prospects

NASA Astrophysics Data System (ADS)

Khomutov, Sergey Y.

2017-10-01

Continuous magnetic measurements at Geophysical Observatory "Paratunka" (PET) of IKIR FEB RAS are performed since 1967. In the new millennium analogue magnetometers were modernized to digital, the technologies of absolute observations were changed, the data processing was completely transferred to computers, and the status of INTERMAGNET observatory was obtained. Currently, the observatory uses the following magnetometers: (a) for absolute observations - DIflux LEMI-203 (theodolite 3T2KP) and Mag-01 (theodolite Wild-T1), Overhauser magnetometers POS-1 and GSM-19W; (b) for variation measurements - fluxgate magnetometers FGE-DTU, FRG-601 and MAGDAS (installed under international agreements of IKIR), vector magnetometers dIdD GSM-19FD and POS-4 with Overhauser sensors and coil systems, scalar magnetometer GSM-90 and induction magnetometer STELAB. During Spring-Autumn season dIdD also is installed at remote station "Karymshina" at distance of 15 km from Observatory. There is monitoring system for monitoring of conditions in which magnetic observations are performed, including the semi-professional weather stations Davis Vantage Pro2 and WS2000 and a network of digital temperature sensors DS19B20 located at various points in magnetic pavilions and outdoor. All measurements are synchronized with the UTC. The results of observations are collected by the IKIR data server from the recorders and loggers, including in real-time. Specialized software was developed (based on MATLAB and Octave packages), which allows automatic and semi-automatic processing of data, the comparison of the results from different magnetometers and presenting final data in formats, defined by international standards, including INTERMAGNET. Significant efforts of observatory staff are direct to archive (raw) magnetic data, a significant part of which has not been entirely processed, is not presented in international data centers and is still not available to the scientific community. Digital images of analog magnetograms have been obtained, the digitization of which allowed to fill the gaps in the hourly data available in the WDC for 1991, 1996-1997. The state of the set of the instruments and databases shows that the observatory "Paratunka" can solve most of the problems that arise in the geomagnetic field researches, including the provision of data for the development of regional and global field models, ground support of magnetometers located on satellites, support of the surface (sea) and aeromagnetic surveys and drilling, providing the data for researches of processes in the lithosphere, magnetosphere and ionosphere over a wide frequency range, and also for a number of applied problems. ARRAY(0x189e680)

Bringing Magnetic Field Data in Real-Time for Researchers on Mobile Devices

NASA Astrophysics Data System (ADS)

Wolf, V. G.; Hampton, D. L.

2013-12-01

Magnetometer data from eight remote stations across Alaska have been collected continuously since the early 1980's by the Geophysical Institute Magnetometer Array (GIMA). These three-axis fluxgate magnetometers, with <1 nT precision, provide data at 1 Hz, which are used to determine the currents associated with auroral activity in the Alaska polar regions. A primary function of the GIMA is to supply magnetic field deflection data in real time to researchers so they can determine when to launch a sub-orbital sounding rocket from the Poker Flat Research Range into the proper auroral conditions. The aurora is a key coupling mechanism between the Earth's magnetosphere and ionosphere, and the magnetometers are used to remotely sense the ionospheric currents associated with aurora. The web-based interface to display the real-time magnetometer data has been upgraded to be fully functional on a wide range of platforms, from desktops to mobile devices. The incoming data stream from each station is recorded in a database and used to populate the real time graphical display. Improvements in data management increased the sampling rate from 5 seconds to 1 second for the display. The displays are highly configurable to allow researchers the flexibility to interpret the magnetic signature they need to make a successful launch decision. The use of Django and Java script technology enabled the system to be structured for rapid expansion when new stations come online and input streams are improved. Data are also available for download within 24 hours of collection. The existence of real-time data has been and will continue to be critical for successful rocket launches.

Demonstration of Advanced EMI Models for Live-Site UXO Discrimination at Waikoloa, Hawaii

DTIC Science & Technology

2015-12-01

magnetic source models PNN Probabilistic Neural Network SERDP Strategic Environmental Research and Development Program SLO San Luis Obispo...SNR Signal to noise ratio SVM Support vector machine TD Time Domain TEMTADS Time Domain Electromagnetic Towed Array Detection System TOI... intrusive procedure, which was used by Parsons at WMA, failed to document accurately all intrusive results, or failed to detect and clear all UXO like

Sock Shaped Internal Strength Member for Towed Arrays

DTIC Science & Technology

hose -shaped sheath. The member has a plurality of longitudinally extending high strength cords formed of braids or strands of high tensile strength...interfering with the sensors’ acoustic sensing capabilities. The hose -shaped sheath contains the tubular-shaped strength member in a non-compressive...relationship to reduce the problems normally associated with flow noise. The cords are braided together in an eye-splice where they are wrapped about

Demonstration of the SeptiStrand benthic microbial fuel cell powering a magnetometer for ship detection

NASA Astrophysics Data System (ADS)

Arias-Thode, Y. Meriah; Hsu, Lewis; Anderson, Greg; Babauta, Jerome; Fransham, Roy; Obraztsova, Anna; Tukeman, Gabriel; Chadwick, D. Bart

2017-07-01

The Navy has a need for monitoring conditions and gathering information in marine environments. Sensors can monitor and report environmental parameters and potential activities such as animal movements, ships, or personnel. However, there has to be a means to power these sensors. One promising enabling technology that has been shown to provide long-term power production in underwater environments is the benthic microbial fuel cells (BMFC). BMFCs are devices that generate energy by coupling bioanodes and biocathodes through an external energy harvester. Recent studies have demonstrated success for usage of BMFCs in powering small instruments and other devices on the seafloor over limited periods of time. In this effort, a seven-stranded BMFC linear array of 30 m was designed to power a seafloor magnetometer to detect passing ship movements through Pearl Harbor, Hawaii. The BMFC system was connected to a flyback energy harvesting circuit that charged the battery powering the magnetometer. The deployment was demonstrated the BMFC supplied power to the battery for approximately 38 days. This is the first large-scale demonstration system for usage of the SeptiStrand BMFC technology to power a relevant sensor.

Demonstration of the Marine Towed Array on Bahia Salinas del Sur Vieques, Puerto Rico

DTIC Science & Technology

2009-02-01

much of the island, particularly in areas close to the shore, has sandy soils . The two islands protecting the mouth of the Bahia and the chain of...investigations, artificial reef projects, soil /water sampling and marine surveys. He is fully bilingual (speaks, reads & writes) English and Spanish...1,000,000 per occurrence General Aggregate - $2,000,000 Workmen’s Compensation and Employer’s Liability Insurance for Employees (including USL

Nested Autonomy for Unmanned Marine Vehicles with MOOS-IvP

DTIC Science & Technology

2010-01-01

standard XML format. As an example, Figure 26 shows the collaborative, mul- tistatic MCM mission by the Unicorn and Macrura Bluefin- 21 AUVs during SWAMSI... Unicorn and Macrura perform synchronized swimming maintaining a constant bistatic angle of 60 deg relative to a proud cylin- drical target (cp...Pianosa, Italy, July–August 2008: The upper left frame shows the Unicorn BF21 AUV with towed DURIP array being deployed from NRV Alliance. The upper

Shallow Water Marine UXO Detection Survey, United States Marine Corps Base, Camp Lejeune, North Carolina

DTIC Science & Technology

2011-04-01

resolution time-domain EM metal detector that is capable of detecting both ferrous and nonferrous metallic objects. The EM61 consists of air-cored...modifications to the Geonics EM61 metal detector . Modifications include higher transmitter power and frequency, faster sampling rates, and flexible...towed array (UUTA) electromagnetic system designed by 3Dgeophysics.com (3Dg) utilizes modified and improved Geonics, Ltd. electromagnetic (EM)61 metal

Detection and Discrimination in One-Pass Using the OPTEMA Towed-Array

DTIC Science & Technology

2014-11-01

pitch, roll , and yaw measurements for the OPTEMA sensor head. The IMU is co-located with the GPS receiver. OPTEMA sensor electronics include the...subtracted from subsequent data sets to isolate the anomaly response. In addition to a background subtraction, a transmitter current normalization is...the survey area. EM3DAcquire provides line following based on the sensor head GPS and IMU data. Using the line following display, the OPTEMA is

Modular Towed Acoustic Sonar Array

DTIC Science & Technology

2014-02-04

Dkt . No...d 11 5 11 0c 11 0d 11 5 14 0 16 0’ 1 60 ’’ 12 0 14 0 12 0 14 0 13 0 14 0 12 0 13 0 12 0 12 0 13 0 14 0 16 0 10 0 d 2 d 3 Dkt . No. 102060 Application...of Non-Acoustic Sensors in Second Sensor Array Dkt . No. 102060 Application No. ?? REPLACEMENT SHEET? /3 1st DRAFT 3 F IG . 3 11 5 16 4 16 8 16 2 16 6 11 5 1 50 11 0b 18 0 17 0 16 6a 16 4a 18 0 10 0 11 0a 15 0

KSC-97PC1127

NASA Image and Video Library

1997-07-24

Applied Physics Laboratory engineers and technicians from Johns Hopkins University test for true perpendicular solar array deployment of the Advanced Composition Explorer (ACE) in KSC’s Spacecraft Assembly and Encapsulation Facility-II (SAEF-II). The white magnetometer boom seen across the solar array panel will deploy the panel once in space. Scheduled for launch on a Delta II rocket from Cape Canaveral Air Station on Aug. 25, ACE will study low-energy particles of solar origin and high-energy galactic particles. The ACE observatory will be placed into an orbit almost a million miles (1.5 million kilometers) away from the Earth, about 1/100 the distance from the Earth to the Sun

KSC-97PC1128

NASA Image and Video Library

1997-07-24

An Applied Physics Laboratory engineer from Johns Hopkins University tests for true perpendicular solar array deployment of the Advanced Composition Explorer (ACE) in KSC’s Spacecraft Assembly and Encapsulation Facility-II (SAEF-II). The white magnetometer boom seen across the solar array panel will deploy the panel once in space. Scheduled for launch on a Delta II rocket from Cape Canaveral Air Station on Aug. 25, ACE will study low-energy particles of solar origin and high-energy galactic particles. The ACE observatory will be placed into an orbit almost a million miles (1.5 million kilometers) away from the Earth, about 1/100 the distance from the Earth to the Sun

The Juno Magnetic Field Investigation

NASA Astrophysics Data System (ADS)

Connerney, J. E. P.; Benn, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.; Murphy, S.; Odom, J.; Oliversen, R.; Schnurr, R.; Sheppard, D.; Smith, E. J.

2017-11-01

The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to ˜20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 × 106 nT per axis) with a resolution of ˜0.05 nT in the most sensitive dynamic range (±1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of view and also provides a continuous record of radiation exposure. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors, and residual spacecraft fields and/or sensor offsets are monitored in flight taking advantage of Juno's spin (nominally 2 rpm) to separate environmental fields from those that rotate with the spacecraft.

The Juno Magnetic Field Investigation

NASA Technical Reports Server (NTRS)

Connerney, J. E. P.; Benna, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.;

High Altitude Towed Glider

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1996-01-01

The concept of using an unmanned towed glider for high altitude scientific research had been previously proposed. This paper examines the feasibility of this concept by determining what impact the various characteristics of the tow line, glider and tow aircraft have on tow line drag. A description of the analysis and computer code used to generate the results is given. The parameters examined were glider altitude, tow aircraft glider separation distance, velocity, tow line drag coefficient and tow line material properties. The results from the analysis show that the tow line drag increases significantly with tow aircraft/glider separation. The drag increased from 940 N (211 lb) with a tow aircraft/glider separation of 3 km to 11,970 N (2691 lb) with a tow aircraft/glider separation of 10 km. The results also show that by varying some of the initial assumptions significant reductions in tow line drag and weight can be obtained. The variables which had the greatest effect on reducing the tow line drag were the decrease in tow aircraft/glider separation distance, the increase in tow line strength and the decrease in glider Mach number.

Using a coherent hydrophone array for observing sperm whale range, classification, and shallow-water dive profiles.

PubMed

Tran, Duong D; Huang, Wei; Bohn, Alexander C; Wang, Delin; Gong, Zheng; Makris, Nicholas C; Ratilal, Purnima

2014-06-01

Sperm whales in the New England continental shelf and slope were passively localized, in both range and bearing, and classified using a single low-frequency (<2500 Hz), densely sampled, towed horizontal coherent hydrophone array system. Whale bearings were estimated using time-domain beamforming that provided high coherent array gain in sperm whale click signal-to-noise ratio. Whale ranges from the receiver array center were estimated using the moving array triangulation technique from a sequence of whale bearing measurements. Multiple concurrently vocalizing sperm whales, in the far-field of the horizontal receiver array, were distinguished and classified based on their horizontal spatial locations and the inter-pulse intervals of their vocalized click signals. The dive profile was estimated for a sperm whale in the shallow waters of the Gulf of Maine with 160 m water-column depth located close to the array's near-field where depth estimation was feasible by employing time difference of arrival of the direct and multiply reflected click signals received on the horizontal array. By accounting for transmission loss modeled using an ocean waveguide-acoustic propagation model, the sperm whale detection range was found to exceed 60 km in low to moderate sea state conditions after coherent array processing.

Conjugate observations of electromagnetic ion cyclotron waves associated with traveling convection vortex events

NASA Astrophysics Data System (ADS)

Kim, Hyomin; Clauer, C. Robert; Gerrard, Andrew J.; Engebretson, Mark J.; Hartinger, Michael D.; Lessard, Marc R.; Matzka, Jürgen; Sibeck, David G.; Singer, Howard J.; Stolle, Claudia; Weimer, Daniel R.; Xu, Zhonghua

2017-07-01

We report on simultaneous observations of electromagnetic ion cyclotron (EMIC) waves associated with traveling convection vortex (TCV) events caused by transient solar wind dynamic pressure (Pd) impulse events. The Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft located near the magnetopause observed radial fluctuations of the magnetopause, and the GOES spacecraft measured sudden compressions of the magnetosphere in response to sudden increases in Pd. During the transient events, EMIC waves were observed by interhemispheric conjugate ground-based magnetometer arrays as well as the GOES spacecraft. The spectral structures of the waves appear to be well correlated with the fluctuating motion of the magnetopause, showing compression-associated wave generation. In addition, the wave features are remarkably similar in conjugate hemispheres in terms of bandwidth, quasiperiodic wave power modulation, and polarization. Proton precipitation was also observed by the DMSP spacecraft during the wave events, from which the wave source region is estimated to be 72°-74° in magnetic latitude, consistent with the TCV center. The confluence of space-borne and ground instruments including the interhemispheric, high-latitude, fluxgate/induction coil magnetometer array allows us to constrain the EMIC source region while also confirming the relationship between EMIC waves and the TCV current system.

Effect of Broadband Nature of Marine Mammal Echolocation Clicks on Click-Based Population Density Estimates

DTIC Science & Technology

2015-09-30

sonar sound and therefore of high relevance to the US Navy, and sperm whale (Physeter macrocephalus) clicks, whose high source level assures long...beaked whale, and Zimmer (2011) for the sperm whale. 5 For background noise we used measurements obtained with the Delphinus towed array at the US...Atlantic Undersea Test and Evaluation Center (AUTEC), where both Blainville’s beaked whales and sperm whales are commonly present. Analysis of the

The Mobile Internet -The Next Big Thing. Electrons & Photons: You Need Both! (BRIEFING CHARTS)

DTIC Science & Technology

2007-03-05

Links Network Centric Warfighting Comms Wired & Wireless Links 20th Century 21th Century The Military Comms Problem Network Centric Operationst t i ti...Small Unit Operations TEL Underwater Vehicles & Towed Arrays RC-135V Rivet Joint Tier II+ UAV Global Hawk E-2C Hawkeye Networked Manned and Unmanned...RF Front-End Solutions ● >20 DARPA/MTO RF Programs across the spectrum - RF & Mixed Signal Electronics - Analog & Digital Photonics Enables Network

The MAVEN Magnetic Field Investigation

NASA Technical Reports Server (NTRS)

Connerney, J. E. P.; Espley, J.; Lawton, P.; Murphy, S.; Odom, J.; Oliversen, R.; Sheppard, D.

2014-01-01

The MAVEN magnetic field investigation is part of a comprehensive particles and fields subsystem that will measure the magnetic and electric fields and plasma environment of Mars and its interaction with the solar wind. The magnetic field instrumentation consists of two independent tri-axial fluxgate magnetometer sensors, remotely mounted at the outer extremity of the two solar arrays on small extensions ("boomlets"). The sensors are controlled by independent and functionally identical electronics assemblies that are integrated within the particles and fields subsystem and draw their power from redundant power supplies within that system. Each magnetometer measures the ambient vector magnetic field over a wide dynamic range (to 65,536 nT per axis) with a quantization uncertainty of 0.008 nT in the most sensitive dynamic range and an accuracy of better than 0.05%. Both magnetometers sample the ambient magnetic field at an intrinsic sample rate of 32 vector samples per second. Telemetry is transferred from each magnetometer to the particles and fields package once per second and subsequently passed to the spacecraft after some reformatting. The magnetic field data volume may be reduced by averaging and decimation, when necessary to meet telemetry allocations, and application of data compression, utilizing a lossless 8-bit differencing scheme. The MAVEN magnetic field experiment may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors and the MAVEN mission plan provides for occasional spacecraft maneuvers - multiple rotations about the spacecraft x and z axes - to characterize spacecraft fields and/or instrument offsets in flight.

The MAVEN Magnetic Field Investigation

NASA Astrophysics Data System (ADS)

Connerney, J. E. P.; Espley, J.; Lawton, P.; Murphy, S.; Odom, J.; Oliversen, R.; Sheppard, D.

2015-12-01

The MAVEN magnetic field investigation is part of a comprehensive particles and fields subsystem that will measure the magnetic and electric fields and plasma environment of Mars and its interaction with the solar wind. The magnetic field instrumentation consists of two independent tri-axial fluxgate magnetometer sensors, remotely mounted at the outer extremity of the two solar arrays on small extensions ("boomlets"). The sensors are controlled by independent and functionally identical electronics assemblies that are integrated within the particles and fields subsystem and draw their power from redundant power supplies within that system. Each magnetometer measures the ambient vector magnetic field over a wide dynamic range (to 65,536 nT per axis) with a resolution of 0.008 nT in the most sensitive dynamic range and an accuracy of better than 0.05 %. Both magnetometers sample the ambient magnetic field at an intrinsic sample rate of 32 vector samples per second. Telemetry is transferred from each magnetometer to the particles and fields package once per second and subsequently passed to the spacecraft after some reformatting. The magnetic field data volume may be reduced by averaging and decimation, when necessary to meet telemetry allocations, and application of data compression, utilizing a lossless 8-bit differencing scheme. The MAVEN magnetic field experiment may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors and the MAVEN mission plan provides for occasional spacecraft maneuvers—multiple rotations about the spacecraft x and z axes—to characterize spacecraft fields and/or instrument offsets in flight.

Search in 8 TeV proton-proton collisions with the MoEDAL monopole-trapping test array

NASA Astrophysics Data System (ADS)

Pinfold, J.; Soluk, R.; Lacarrère, D.; Katre, A.; Mermod, P.; Bendtz, K.; Milstead, D.

2014-06-01

The magnetic monopole appears in theories of spontaneous gauge symmetry breaking and its existence would explain the quantisation of electric charge. MoEDAL is the latest approved LHC experiment, designed to search directly for monopoles produced in high-energy collisions. It has now taken data for the first time. The MoEDAL detectors are based on two complementary techniques: nuclear-track detectors are sensitive to the high-ionisation signature expected from a monopole, and the magnetic monopole trapper (MMT) relies on the stopping and trapping of monopoles inside an aluminium array which is then analysed with a superconducting magnetometer. The first results obtained with the MoEDAL MMT test array deployed in 2012 are presented. This experiment probes monopoles carrying a multiple of the fundamental unit magnetic charge for the first time at the LHC.

The behavioural response of migrating humpback whales to a full seismic airgun array.

PubMed

Dunlop, Rebecca A; Noad, Michael J; McCauley, Robert D; Kniest, Eric; Slade, Robert; Paton, David; Cato, Douglas H

2017-12-20

Despite concerns on the effects of noise from seismic survey airguns on marine organisms, there remains uncertainty as to the biological significance of any response. This study quantifies and interprets the response of migrating humpback whales ( Megaptera novaeangliae ) to a 3130 in 3 (51.3l) commercial airgun array. We compare the behavioural responses to active trials (array operational; n = 34 whale groups), with responses to control trials (source vessel towing the array while silent; n = 33) and baseline studies of normal behaviour in the absence of the vessel ( n = 85). No abnormal behaviours were recorded during the trials. However, in response to the active seismic array and the controls , the whales displayed changes in behaviour. Changes in respiration rate were of a similar magnitude to changes in baseline groups being joined by other animals suggesting any change group energetics was within their behavioural repertoire. However, the reduced progression southwards in response to the active treatments, for some cohorts, was below typical migratory speeds. This response was more likely to occur within 4 km from the array at received levels over 135 dB re 1 µPa 2 s. © 2017 The Author(s).

Development Of Eej Model Based On Dense Ground-based Magnetometer Array

NASA Astrophysics Data System (ADS)

Matsushita, H.; Yoshikawa, A.; Uozumi, T.; Fujimoto, A.; Abe, S.; Ishitsuka I, J. K.; Veliz, O.; Rosales, D.; Safor, E.; Beteta, V.

2016-12-01

Equatorial Electro-jet(here after called EEJ) is the electric current which flows very narrow region in ionosphere of the earth, which is between +- 3 degree from dip latitude. The EEJ was noticed as the significant enhancement of daily variation of magnetic field, and later Hirono, (1950) explained it by adapting Cowling effect to the ionosphere of the earth. The EE index, is one of ICSWSE space weather indices, was developed by Uozumi et al., (2008). Then, ICSWSE has continued to monitor the EEJ activity by using this EE index. Fujimoto et al., (2016) investigated the relationship between solar activity and long term variation of EEJ, and Hamid et al., (2015) investigated longitudinal dependency of EEJ, both of them were based on EE index. The EE index provides EDst value, which is correspond to magnetic field change at dip equator caused by magnetospheric current such as ring current, and EUEL value, which is correspond to the one caused by ionospheric current such as EEJ and Sq. However, actual EEJ is not magnetic field but the current, and it has not only current intensity but also the width. Some previous paper reported the EEJ structure such as current density or the width of EEJ using satellite data (e.g. Lühr et al., 2004; Jadhav et al., 2002), which is good when it checks the longitudinal dependency because it shifts longitude in a day. However, the ground-based magnetometer may be well useful to investigate the day-to-day variability of EEJ because it is fixed to same location. So, we developed a model of EEJ, which can estimate the EEJ current structure by ground magnetometer using dense magnetometer array near dip equator. In this study, the EEJ structures along 75W and 135E longitude are represented, and are compared each other. The result shows that large standard deviation of both current density and the half width are identified, while previous studies reported constant half width (e.g. Lühr et al., 2004). When our EEJ model is compared with CM4 model, which was developed by Sabaka et al., (2004), large discrepancy between them was identified, so it should be more discussed the reason to produce more accurate EEJ model.

ESTCP UXO Discrimination Study. MTADS Demonstration at Camp Sibert Magnetometer / EM61 MkII / GEM-3 Arrays, Gadsden, AL, April 2007

DTIC Science & Technology

2008-08-21

Yuma Proving Ground Open Field ............................................................................... 76 B.3.1 Response Stage... Yuma Proving Ground ZIP (250) Iomega ZIP disk (250 MB version) xv ACKNOWLEDGEMENTS Glenn Harbaugh and Daniel Steinhurst (P.I.) of Nova Research...sites at Aberdeen Proving Ground and Yuma Proving Ground in 2003 and 2004 [6]. At each of the sites, the Calibration Lanes, the Blind Test Grid

2002 Airborne Geophysical Survey at Pueblo of Isleta Bombing Targets, New Mexico, April 10 May 6, 2002 (Rev 1)

DTIC Science & Technology

2005-12-01

helicopter geophysical survey performed by US Army Engineering Support Center, Huntsville (USAESCH) and Oak Ridge National Laboratory ( ORNL ) over areas...Array Detection System NAD North American Datum ORAGS Oak Ridge Airborne Geophysical System ORNL Oak Ridge National Laboratory RMS Root...used by ORNL in 1999 for.....................5 Figure 2.4 ORAGS-Hammerhead airborne magnetometer system used at Badlands Bombing Range in FY2000

Vertical Cable Seismic Survey for SMS exploration

NASA Astrophysics Data System (ADS)

Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hotoshi; Mizohata, Shigeharu

2014-05-01

The Vertical Cable Seismic (VCS) survey is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by sea-surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. Because the VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed it for the SMS survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We have been developing the VCS survey system, including not only data acquisition hardware but data processing and analysis technique. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of these surveys are from 100m up to 2100 m. Through these experiments, our VCS data acquisition system has been also completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system is available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed a new approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In 2013, we have carried out the second VCS survey using the surface-towed high-voltage sparker and ocean bottom source in the Izena Cauldron, which is one of the most promising SMS areas around Japan. The positions of ocean bottom source estimated by this method are consistent with the VCS field records. The VCS data with the sparker have been processed with 3D PSTM. It gives the very high resolution 3D volume deeper than two hundred meters. Our VCS system has been demonstrated as a promising survey tool for the SMS exploration.

Novel semi-airborne CSEM system for the exploration of mineral resources

NASA Astrophysics Data System (ADS)

Nittinger, Christian; Cherevatova, Maria; Becken, Michael; Rochlitz, Raphael; Günther, Thomas; Martin, Tina; Matzander, Ulrich

2017-04-01

Within the DESMEX project (Deep Electromagnetic Sounding for Mineral Exploration), a semi-airborne CSEM system for mineral exploration is developed which aims to achieve a penetration depth of 1 km with a large areal coverage. Harmonically Time-varying electrical currents are injected with a grounded transmitter in order to measure the electric field on the ground and induced magnetic fields with highly sensitive magnetic sensors in the air. To measure the magnetic field and its variations, three-axis induction coils (MFS-11e by Metronix) and fluxgate sensors (Bartington FGS-03) are mounted on the platform towed by a helicopter. In addition, there is a SQUID based magnetometer, developed by IPHT and Supracon AG, available for future measurements. We deploy the different magnetometer sensors to cover a broad frequency range of 1-10000Hz. During the flight, the sensors encounter a broad variety of motion/vibration which produces noise in the magnetic field sensors. Therefore, a high accuracy motion tracking system is installed within the bird and a low vibrating system design needs to be considered in the airborne sensor platform. We conducted several flights with different source positions in a test area in Germany, which is already covered by ground based measurements. Based on the data, we discuss possible calibration schemes which are needed to overcome orthogonality and scaling errors in the fluxgate data as well as orientation errors. We apply noise correction schemes to the data and calculate transfer functions between the magnetic field and the source current. First 1-D inversion models based on the estimated transfer functions are calculated and compared to existing conductivity models from DC geoelectrics and helicopter electromagnetic (HEM) measurements.

The Road To The Objective Force. Armaments for the Army Transformation

DTIC Science & Technology

2001-06-18

Vehicle Fire Support Vehicle •TOW 2B Anti-Tank Capability Under Armor •Detection of NBC Hazards Mortar Carrier •Dismounted M121 120mm MRT Initially...engaged from under armor M6 Launchers (x4) Staring Array Thermal Sight Height reduction for air transport Day Camera Target Acq Sight Armament Remote...PM BCT ANTI-TANK GUIDED MISSILE VEHICLE • TOWII • ITAS (Raytheon) - 2 Missiles • IBAS Day Camera • Missile is Remotely Fired Under Armor • M6 Smoke

Wear Test Results of Candidate Materials for the OK-542 Towed Array Handling Machine Level Winder

DTIC Science & Technology

1994-12-29

Stainless Steel, Inconel 625 , Nickel-Aluminum-Bronze, and Titanium. The specialty materials: Inconel 625 , Monel, Stainless and Stellite, were clad-welded...metals on a base of 1040 Carbon Steel. Finally, an economic carbide coating was deposited on a 316 Stainless Steel and Inconel 625 sample. Within a...damage in the shortest period of time. The Inconel 625 bar stock that was tested performed the best. It sustained the least amount of damage for one

Commercial-off-the-Shelf Vehicles for Towed Array Magnetometry

DTIC Science & Technology

2009-09-01

dump bed on the back, has upright seating for two adults, has the seats oriented side-by-side, and has a steering wheel and brake and accelerator... pedals like a car. By way of example, a ubiquitous side-by-side UTV is the John Deere Gator. The objective of this project was to test a number of...different angle , and one set of biases will not be able to take out all of the streaks. This raises the second issue. Because the bidirectional

Commercial-Off-The-Shelf Vehicles for Towed Array Magnetometry

DTIC Science & Technology

2009-09-01

a steering wheel, and brake and accelerator pedals like a car. By way of example, a ubiquitous side-by- side UTV is the John Deere Gator. The...tire tracks are imperfectly 42 followed. These new tracks will be at a slightly different angle , and one set of biases will not be able to take...tracks at an angle relative to the north-south traverses that we ran. In addition, we surveyed into the muddy wet section at the western end of the site

Process for preparing composite articles from composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

A composite article is prepared by forming a continuous tow of continuous carbon fibers, forming a continuous tow of thermoplastic polymer fibers, uniformly and continuously spreading the thermoplastic polymer fibers to a selected width, uniformly and continuously spreading the carbon fiber tow to a width that is essentially the same as the selected width for the thermoplastic polymer fiber tow, intermixing the tows intimately, uniformly and continuously, in a relatively tension-free state, continuously withdrawing the intermixed tow and applying the tow to a mold and heating the tow.

The THEMIS Array of Ground-based Observatories for the Study of Auroral Substorms

NASA Astrophysics Data System (ADS)

Mende, S. B.; Harris, S. E.; Frey, H. U.; Angelopoulos, V.; Russell, C. T.; Donovan, E.; Jackel, B.; Greffen, M.; Peticolas, L. M.

2008-12-01

The NASA Time History of Events and Macroscale Interactions during Substorms (THEMIS) project is intended to investigate magnetospheric substorm phenomena, which are the manifestations of a basic instability of the magnetosphere and a dominant mechanism of plasma transport and explosive energy release. The major controversy in substorm science is the uncertainty as to whether the instability is initiated near the Earth, or in the more distant >20 Re magnetic tail. THEMIS will discriminate between the two possibilities by using five in-situ satellites and ground-based all-sky imagers and magnetometers, and inferring the propagation direction by timing the observation of the substorm initiation at multiple locations in the magnetosphere. An array of stations, consisting of 20 all-sky imagers (ASIs) and 30-plus magnetometers, has been developed and deployed in the North American continent, from Alaska to Labrador, for the broad coverage of the nightside magnetosphere. Each ground-based observatory (GBO) contains a white light imager that takes auroral images at a 3-second repetition rate (“cadence”) and a magnetometer that records the 3 axis variation of the magnetic field at 2 Hz frequency. The stations return compressed images, “thumbnails,” to two central databases: one located at UC Berkeley and the other at the University of Calgary, Canada. The full images are recorded at each station on hard drives, and these devices are physically returned to the two data centers for data copying. All data are made available for public use by scientists in “browse products,” accessible by using internet browsers or in the form of downloadable CDF data files (the “browse products” are described in detail in a later section). Twenty all-sky imager stations are installed and running at the time of this publication. An example of a substorm was observed on the 23rd of December 2006, and from the THEMIS GBO data, we found that the substorm onset brightening of the equatorward arc was a gradual process (>27 seconds), with minimal morphology changes until the arc breaks up. The breakup was timed to the nearest frame (<3 s) and located to the nearest latitude degree at about ±3oE in longitude. The data also showed that a similar breakup occurred in Alaska ˜10 minutes later, highlighting the need for an array to distinguish prime onset.

Continuous, linearly intermixed fiber tows and composite molded article thereform

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

2000-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a carbon fiber tow; (b) forming a thermoplastic polymeric fiber tow; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

Process for preparing tows from composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

A continuous, substantially uniform tow useful in forming composite molded articles is prepared by forming a continuous tow of continuous carbon fibers, forming a continuous tow of thermoplastic polymer fibers to a selected width, uniformly and continuously spreading the carbon fiber two to a width that is essentially the same as the selected width for the thermoplastic polymer fiber tow, intermixing the tows intimately, uniformly and continuously, in a relatively tension-free state, and continuosuly withdrawing the intermixed tow.

Coordinated Polar Spacecraft, Geosynchronous Spacecraft, and Ground-based Observations of Magnetopause Oscillations and Pc5 Waves in the Magnetosphere

NASA Technical Reports Server (NTRS)

Le, G.; Chen, S.; Zheng, Y.; Russell, C. T.; Slavin, J. A.; Huang, C.-S.; Petrinec, S. S.; Moore, T. E.; Samson, J.; Singer, H. J.

2005-01-01

In this paper, we present in situ observations of surface waves at the magnetopause and oscillatory magnetospheric field lines, and coordinated observations Pc5 waves at geosynchronous orbit by the GOES spacecraft, and on the ground by CANOPUS and 210 Degree Magnetic Meridian (210MMJ magnetometer arrays. On February 7,2002 during a highspeed solar wind stream, the Polar spacecraft was skimming the magnetopause in a post-noon meridian plane for approximately 3 hours. During this interval, it made two short excursions and a few partial crossings into the magnetosheath and observed quasi-periodic cold ion bursts in the region adjacent to the magnetopause current layer. The multiple magnetopause crossings as well as the velocity of the cold ion bursts indicate that the magnetopause was oscillating with about 6 minute period. Simultaneous observations of Pc5 waves at geosynchronous orbit by the GOES spacecraft and on the ground by the CANOPUS magnetometer array reveal that these magnetospheric pulsations were forced oscillations of magnetic field lines directly driven by the magnetopause oscillations. The magnetospheric pulsations occurred only in a limited longitudinal region in the post-noon dayside sector, and were not a global phenomenon as one would expect for global field line resonance. Thus, the magnetopause oscillations at the source were also limited to a localized region spanning about 4 hours in local time.

Nightside High Latitude Magnetic Impulse Events

NASA Astrophysics Data System (ADS)

Engebretson, M. J.; Connors, M. G.; Braun, D.; Posch, J. L.; Kaur, M.; Guillon, S.; Hartinger, M.; Kim, H.; Behlke, R.; Reiter, K.; Jackel, B. J.; Russell, C. T.

2017-12-01

High latitude Magnetic Impulse Events (MIEs), isolated pulses with periods 5-10 min, were first noted in ground-based magnetometer data near local noon, and are now understood to be signatures of transient pressure increases in the solar wind (sudden impulses - SIs) and/or in the ion foreshock (traveling convection vortex events - TCVs). However, solitary pulses with considerably larger amplitude (ΔB up to 1500 nT) have often been observed in the night sector at these same latitudes. These events are not directly associated with transient external pressure increases, and are often large enough to produce significant ground induced currents. Although many night sector MIEs occur in association with substorm signatures, others appear to be very isolated. We present here a survey of intense MIE events identified in magnetometer data from the AUTUMNX and MACCS arrays in eastern Arctic Canada at all local times between July 1, 2014 and June 30, 2017. We also show maps of horizontal and vertical perturbations and maximum dB/dt values, as well as sample magnetograms, for several example events using data from these and other arrays in Arctic Canada, as well as in West Greenland and Antarctica, the latter to show the conjugate nature of these events. A basic relation to GIC data in the Hydro-Québec electrical transmission network in eastern Canada has been determined and will be discussed.

GreenCube and RocketCube: Low-Resource Sensorcraft for Atmospheric and Ionospheric Science

NASA Astrophysics Data System (ADS)

Bracikowski, P. J.; Lynch, K. A.; Slagle, A. K.; Fagin, M. H.; Currey, S. R.; Siddiqui, M. U.

2009-12-01

In situ atmospheric and ionospheric studies benefit greatly from the ability to separate variations in space from variations in time. Arrays of many probes are a method of doing this, but because of the technical character and expense of developing large arrays, so far probe arrays have been the domain of well-funded science missions. CubeSats and low-resource craft (``Picosats") are an avenue for bringing array-based studies of the atmosphere and ionosphere into the mainstream. The Lynch Rocket Lab at Dartmouth College is attempting to develop the instruments, experience, and heritage to implement arrays of many low-resource sensorcraft while doing worthwhile science in the development process. We are working on two CubeSat projects to reach this goal: GreenCube for atmospheric studies and RocketCube for ionospheric studies. GreenCube is an undergraduate student-directed high-altitude balloon-borne 3U CubeSat. GreenCube I was a bus, telemetry, and mechanical system development project. GreenCube I flew in the fall of 2008. The flight was successfully recovered and tracked over the 97km range and through the 29km altitude rise. GreenCube I carried six thermal housekeeping sensors, a GPS, a magnetometer, and a HAM radio telemetry system with a reporting rate of once every 30 seconds. The velocity profile obtained from the GPS data implies the presence of atmospheric gravity waves during the flight. GreenCube II flew in August 2009 with the science goal of detecting atmospheric gravity waves over the White Mountains of New Hampshire. Two balloons with identical payloads were released 90 seconds apart to make 2-point observations. Each payload carried a magnetometer, 5 thermistors for ambient temperature readings, a GPS, and an amateur radio telemetry system with a 7 second reporting cadence. A vertically oriented video camera on one payload and a horizontally oriented video camera on the other recorded the characteristics of gravity waves in the nearby clouds. We expect to be able to detect atmospheric gravity waves from the GPS-derived position and velocity of the two balloons and the ambient temperature profiles. Preliminary analysis of the temperature data shows indications of atmospheric gravity waves. RocketCube is a graduate student-designed low-resource sensorcraft development project being designed for future ionospheric multi-point missions. The FPGA-based bus system, based on GreenCube’s systems, will be able to control and digitize analog data from any low voltage instrument and telemeter that data. RocketCube contains a GPS and high-resolution magnetometer for position and orientation information. The Lynch Rocket Lab's initial interest in developing RocketCube is to investigate the k-spectrum of density irregularities in the auroral ionosphere. To this end, RocketCube will test a new Petite retarding potential analyzer Ion Probe (PIP) for examining subsonic and supersonic thermal ion populations in the ionosphere. The tentatively planned launch will be from a Wallops Flight Facility sounding rocket test flight in 2011. RocketCube serves as a step toward a scientific auroral sounding rocket mission that will feature an array of subpayloads to study the auroral ionosphere.

Investigation of the Forces Acting on Gliders in Automobile-pulley-winch and Airplane Towed Flight

NASA Technical Reports Server (NTRS)

Klemperer, W B

1942-01-01

The magnitude, the direction, and the fluctuation of towing forces exerted upon gliders by towing them aloft behind an automobile, by means of a winch, and by airplane were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests the towing forces did not exceed 92 percent of the gross weight of the glider. The results indicate that in pulley and winch towing the towing forces are of about the same magnitude as in automobile towing. Speed increases in the accelerated phases of the towing jerks encountered in airplane towing can readily become critical as speeds in excess of placard speeds can be attained. Passage through the slipstream of the towing airplane can be equivalent to a severe gust that, at high speed, may impose high wing loads and require large control moments.

Fiber coating method

DOEpatents

Corman, Gregory Scot

2003-04-15

A coating is applied to reinforcing fibers arranged into a tow by coaxially aligning the tow with an adjacent separation layer and winding or wrapping the tow and separation layer onto a support structure in an interleaved manner so that the separation layer separates a wrap of the tow from an adjacent wrap of the tow. A coating can then be uniformly applied to the reinforcing fibers without defects caused by fiber tow to fiber tow contact. The separation layer can be a carbon fiber veil.

Passive acoustic monitoring using a towed hydrophone array results in identification of a previously unknown beaked whale habitat.

PubMed

Yack, Tina M; Barlow, Jay; Calambokidis, John; Southall, Brandon; Coates, Shannon

2013-09-01

Beaked whales are diverse and species rich taxa. They spend the vast majority of their time submerged, regularly diving to depths of hundreds to thousands of meters, typically occur in small groups, and behave inconspicuously at the surface. These factors make them extremely difficult to detect using standard visual survey methods. However, recent advancements in acoustic detection capabilities have made passive acoustic monitoring (PAM) a viable alternative. Beaked whales can be discriminated from other odontocetes by the unique characteristics of their echolocation clicks. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the Southern California Bight (SCB) and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study. The three year field effort has resulted in (1) the successful classification and tracking of Cuvier's (Ziphius cavirostris), Baird's (Berardius bairdii), and unidentified Mesoplodon beaked whale species and (2) the identification of areas of previously unknown beaked whale habitat use. Identification of habitat use areas will contribute to a better understanding of the complex relationship between beaked whale distribution, occurrence, and preferred habitat characteristics on a relatively small spatial scale. These findings will also provide information that can be used to promote more effective management and conservation of beaked whales in the SCB, a heavily used Naval operation and training region.

An experimental assessment of resistance reduction and wake modification of a kvlcc model by using outer-layer vertical blades

NASA Astrophysics Data System (ADS)

An, Nam Hyun; Ryu, Sang Hoon; Chun, Ho Hwan; Lee, Inwon

2014-03-01

In this study, an experimental investigation has been made of the applicability of outer-layer vertical blades to real ship model. After first devised by Hutchins and Choi (2003), the outer-layer vertical blades demonstrated its effectiveness in reducing total drag of flat plate (Park et al., 2011) with maximum drag reduction of 9.6%. With a view to assessing the effect in the flow around a ship, the arrays of outer-layer vertical blades have been installed onto the side bottom and flat bottom of a 300k KVLCC model. A series of towing tank test has been carried out to investigate resistance (CTM) reduction efficiency and improvement of stern wake distribution with varying geometric parameters of the blades array. The installation of vertical blades led to the CTM reduction of 2.15~2.76% near the service speed. The nominal wake fraction was affected marginally by the blades array and the axial velocity distribution tended to be more uniform by the blades array.

MMS, Van Allen Probes, and Ground-based Magnetometer Observations of a Compression-induced EMIC Wave Event

NASA Astrophysics Data System (ADS)

Capman, N.; Engebretson, M.; Posch, J. L.; Cattell, C. A.; Tian, S.; Wygant, J. R.; Kletzing, C.; Lessard, M.; Anderson, B. J.; Russell, C. T.; Reeves, G. D.; Fuselier, S. A.

2016-12-01

A 0.5-1.0 Hz electromagnetic ion cyclotron (EMIC) wave event was observed on December 14, 2015 from 13:26 to 13:28 UT at the four MMS satellites (L= 9.5, MLT= 13.0, MLAT= -24.4, peak amplitude 7 nT), and both Van Allen probes (RBSP-A: L= 5.7, MLT= 12.8, MLAT= 19.5, peak amplitude 5 nT; RBSP-B: L= 4.3, MLT= 14.2, MLAT= 11.3, peak amplitude 1 nT). On the ground, it was observed by search coil magnetometers at Halley Bay and South Pole, Antarctica, and Sondrestromfjord, Greenland, and by fluxgate magnetometers of the MACCS array at Pangnirtung and Cape Dorset in Arctic Canada. This event was preceded by a small increase of the solar wind pressure of 3 nPa from 13:10 to 13:20 UT. The proton distributions at Van Allen probe A confirm that the compression increased the pitch angle anisotropy in 10 keV ring current protons. The wave forms were very similar at the four MMS spacecraft indicating that the coherence-scale of the wave packets is larger than the inter-spacecraft separations of 20 km at the time. Inter-comparison of the wave signals at the four MMS spacecraft are used to assess the characteristics of the waves and estimate their spatial scales transverse and parallel to the background magnetic field.

Monitoring of Space and Earth electromagnetic environment by MAGDAS project: Collaboration with IKIR - Introduction to ICSWSE/MAGDAS project

NASA Astrophysics Data System (ADS)

Yoshikawa, Akimasa; Fujimoto, Akiko; Ikeda, Akihiro; Uozumi, Teiji; Abe, Shuji

2017-10-01

For study of coupling processes in the Solar-Terrestrial System, International Center for Space Weather Science and Education (ICSWSE), Kyushu University has developed a real time magnetic data acquisition system (the MAGDAS project) around the world. The number of observational sites is increasing every year with the collaboration of host countries. Now at this time, the MAGDAS Project has installed 78 real time magnetometers - so it is the largest magnetometer array in the world. The history of global observation at Kyushu University is over 30 years and number of developed observational sites is over 140. Especially, Collaboration between IKIR is extended back to 1990's. Now a time, we are operating Flux-gate magnetometer and FM-CW Radar. It is one of most important collaboration for space weather monitoring. By using MAGDAS data, ICSWSE produces many types of space weather index, such as EE-index (for monitoring long tern and shot term variation of equatorial electrojet), Pc5 index (for monitoring solar-wind velocity and high energy electron flux), Sq-index (for monitoring global change of ionospheric low and middle latitudinal current system), and Pc3 index (for monitoring of plasma density variation at low latitudes). In this report, we will introduce recent development of MAGDAS/ICSWSE Indexes project and topics for new open policy for MAGDAS data will be also discussed.

The Development of a High-Power, Low-Frequency Underwater Acoustic Source for Use in a Deep-Towed Geophysical Array Section

DTIC Science & Technology

1982-11-15

Metca) for each ring 6 Aluminum orirlce end ring 15 Rubber bumpers 7 Back plate inner boot ring 16 Castor oil rill-fluid I ’)-ring %eals I ’ Nikel ...electrode .ab% with hook-up wire -ig. 6 - Sectional v-icw orf ISRI) typc (662 tran.dhcer 9 YOUNG, TIMS. AND HENRIQUFZ 0.42 m. Approximately 85% of the...electrical leads for each ring are routed to individual bulkhead connectors on the trans- ducer back plate with high-voltage silicone-jacketed hookup wire

Thermomechanical Characterization of SiC Fiber Tows and Implications for CMC

NASA Technical Reports Server (NTRS)

Yun, H. M.; DiCarlo, J. A.

1999-01-01

In order to better understand SiC fiber behavior within CMC microstructures, mechanical tests were performed on multifilament tows consisting of different types of as produced and pretreated fibers. Tensile strengths of tows and single fibers were measured at room temperature for nonstoichiometric Hi-Nicalon and ZMI fibers and for stoichiometric Hi-Nicalon-S, Tyranno SA. and Sylramic fibers. Based on simple bundle theory, measured strengths for as-produced and sized tows were in general agreement with the single fiber results. However, after sizing removal under inert conditions, tow strengths for the coarser grained stoichiometric fibers were typically lower than those predicted from individual fiber data. This effect is attributed to enhanced fiber-fiber mechanical interaction caused by sizing removal from the rough surfaces of these fibers. In support of this, tow strengths remained high for those fiber types with fine grains or excess surface carbon; and, when re-coated with a BN interphase coating, tow strengths for the coarser grained fibers returned to their as-produced values. When the tows were pretreated in air at intermediate temperatures, tow strengths decreased in a manner that could be correlated with the oxidation characteristics of each fiber type as measured by thermogravimetric analysis. The creep and rupture properties of Hi-Nicalon and Sylramic tows were also measured in air and argon from 1200 to 1400 C. Although displaying transient and environmental effects similar to single fibers, the tows crept faster at short times and slower at long times. This resulted in the tow rupture strengths at long time being much greater than the rupture strengths of single fibers. The CMC implications of the tow results are discussed, as well as the benefits and limitations of tow testing.

Variable Length Inflatable Ramp Launch and Recovery System

DTIC Science & Technology

2016-09-22

deployment and when not in use, for retraction . [0017] The positioning cart is the primary interface with the tow body by hosting a capture and swing...the air beams 20. The tow cable winch 14 also extends the tow cable 15 into the water to tow a tow body 100 during deployment and retraction during...for deployment and retract back into the ABDF when not in use. The positioning cart 24 is the primary interface with the tow body by hosting the

M2-F1 in flight over lakebed on tow line

NASA Image and Video Library

1963-08-16

After initial ground-tow flights of the M2-F1 using the Pontiac as a tow vehicle, the way was clear to make air tows behind a C-47. The first air tow took place on 16 August 1963. Pilot Milt Thompson found that the M2-F1 flew well, with good control. This first flight lasted less than two minutes from tow-line release to touchdown. The descent rate was 4,000 feet per minute.

Eclipse - tow flight closeup and release

NASA Technical Reports Server (NTRS)

1998-01-01

This clip, running 15 seconds in length, shows the QF-106 'Delta Dart' gear down, with the tow rope secured to the attachment point above the aircraft nose. First there is a view looking back from the C-141A, then looking forward from the nose of the QF-106, and finally a shot of the aircraft being released from the tow rope. NASA Dryden Flight Research Center, Edwards, California, supported a Kelly Space and Technology, Inc. (KST)/U.S. Air Force project known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The purpose of the project was to demonstrate a reusable tow launch vehicle concept that had been conceived and patented by KST. Kelly Space obtained a contract with the USAF Research Laboratory for the tow launch demonstration project under the Small Business Innovation Research (SBIR) program. The USAF SBIR contract included the modifications to turn the QF-106 into the Experimental Demonstrator #1 (EXD-01), and the C141A aircraft to incorporate the tow provisions to link the two aircraft, as well as conducting flight tests. The demonstration consisted of ground and flight tests. These tests included a Combined Systems Test of both airplanes joined by a tow rope, a towed taxi test, and six towed flights. The primary goal of the project was demonstrating the tow phase of the Eclipse concept using a scaled-down tow aircraft (C-141A) and a representative aerodynamically-shaped aircraft (QF-106A) as a launch vehicle. This was successfully accomplished. On December 20, 1997, NASA research pilot Mark Stucky flew a QF-106 on the first towed flight behind an Air Force C-141 in the joint Eclipse project with KST to demonstrate a reusable tow launch vehicle concept developed by KST. Kelly Space and Technology hoped to use the data from the tow tests to validate a tow-to-launch procedure for reusable space launch vehicles. Stucky flew six successful tow tests between December 1997 and February 6, 1998. On February 6, 1998, the sixth and final towed flight brought the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable; actual flight-measured values of tow rope tension were well within predictions made by the simulation, aerodynamic characteristics and elastic properties of the tow rope were a significant component of the towing system; and the Dryden high-fidelity simulation provided a representative model of the performance of the QF-106 and C-141A airplanes in tow configuration. Total time on tow for the entire project was 5 hours, 34 minutes, and 29 seconds. All six flights were highly productive, and all project objectives were achieved. All three of the project objectives were successfully accomplished. The objectives were: demonstration of towed takeoff, climb-out, and separation of the EXD-01 from the towing aircraft; validation of simulation models of the towed aircraft systems; and development of ground and flight procedures for towing and launching a delta-winged airplane configuration safely behind a transport-type aircraft. NASA Dryden served as the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, simulation, instrumentation, range support, research pilots, and chase aircraft for the test series. Dryden personnel also performed the modifications to convert the QF-106 into the piloted EXD-01 aircraft. During the early flight phase of the project, Tracor, Inc. provided maintenance and ground support for the two QF-106 airplanes.The Air Force Flight Test Center (AFFTC), Edwards, California, provided the C-141A transport aircraft for the project, its flight and engineering support, and the aircrew. Kelly Space and Technology provided the modification design and fabrication of the hardware that was installed on the EXD-01 aircraft. Kelly Space and Technology hopes to use the data gleaned from the tow tests to develop a series of low-cost reusable launch vehicles, in particular to gain experience towing delta-wing aircraft having high wing loading, and in general to demonstrate various operational procedures such as ground processing and abort scenarios. The first successful towed flight occurred on Dec. 20, 1997. Prior to this first tow test flight, the C-141A and EXD-01 were used to conduct a series of tethered taxi tests to validate the tow procedures. Before these tethered taxi tests, a successful joint flight test was conducted in late October 1996, by Dryden, AFFTC, and KST, in which one of the Dryden F-18 chase aircraft flew at various ranges and locations behind the C-141A to define the wake turbulence and wingtip vortex environment. This flight test was replicated in July 1997, with an unmodified QF-106 flight proficiency aircraft.

Broadband spectra of seismic survey air-gun emissions, with reference to dolphin auditory thresholds.

PubMed

Goold, J C; Fish, P J

1998-04-01

Acoustic emissions from a 2120 cubic in air-gun array were recorded through a towed hydrophone assembly during an oil industry 2-D seismic survey off the West Wales Coast of the British Isles. Recorded seismic pulses were sampled, calibrated, and analyzed post-survey to investigate power levels of the pulses in the band 200 Hz-22 kHz at 750-m, 1-km, 2.2-km, and 8-km range from source. At 750-m range from source, seismic pulse power at the 200-Hz end of the spectrum was 140 dB re: 1 microPa2/Hz, and at the 20-kHz end of the spectrum seismic pulse power was 90 dB re: 1 microPa2/Hz. Although the background noise levels of the seismic recordings were far in excess of ambient, due to the proximity of engine, propeller, and flow sources of the ship towing the hydrophone, seismic power dominated the entire recorded bandwidth of 200 Hz-22 kHz at ranges of up to 2 km from the air-gun source. Even at 8-km range seismic power was still clearly in excess of the high background noise levels up to 8 kHz. Acoustic observations of common dolphins during preceding seismic surveys suggest that these animals avoided the immediate vicinity of the air-gun array while firing was in progress, i.e., localized disturbance occurred during seismic surveying. Although a general pattern of localized disturbance is suggested, one specific observation revealed that common dolphins were able to tolerate the seismic pulses at 1-km range from the air-gun array. Given the high broadband seismic pulse power levels across the entire recorded bandwidth, and known auditory thresholds for several dolphin species, we consider such seismic emissions to be clearly audible to dolphins across a bandwidth of tens on kilohertz, and at least out to 8-km range.

Eclipse takeoff and flight

NASA Technical Reports Server (NTRS)

1998-01-01

This 25-second clip shows the QF-106 'Delta Dart' tethered to the USAF C-141A during takeoff and in flight. NASA Dryden Flight Research Center, Edwards, California, supported a Kelly Space and Technology, Inc. (KST)/U.S. Air Force project known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The purpose of the project was to demonstrate a reusable tow launch vehicle concept that had been conceived and patented by KST. Kelly Space obtained a contract with the USAF Research Laboratory for the tow launch demonstration project under the Small Business Innovation Research (SBIR) program. The USAF SBIR contract included the modifications to turn the QF-106 into the Experimental Demonstrator #1 (EXD-01), and the C141A aircraft to incorporate the tow provisions to link the two aircraft, as well as conducting flight tests. The demonstration consisted of ground and flight tests. These tests included a Combined Systems Test of both airplanes joined by a tow rope, a towed taxi test, and six towed flights. The primary goal of the project was demonstrating the tow phase of the Eclipse concept using a scaled-down tow aircraft (C-141A) and a representative aerodynamically-shaped aircraft (QF-106A) as a launch vehicle. This was successfully accomplished. On December 20, 1997, NASA research pilot Mark Stucky flew a QF-106 on the first towed flight behind an Air Force C-141 in the joint Eclipse project with KST to demonstrate the reusable tow launch vehicle concept developed by KST. Kelly hoped to use the data from the tow tests to validate a tow-to-launch procedure for reusable space launch vehicles. Stucky flew six successful tow tests between December 1997 and February 6, 1998. On February 6, 1998, the sixth and final towed flight brought the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable; actual flight measured values of tow rope tension were well within predictions made by the simulation, aerodynamic characteristics and elastic properties of the tow rope were a significant component of the towing system; and the Dryden high-fidelity simulation provided a representative model of the performance of the QF-106 and C-141A airplanes in tow configuration. Total time on tow for the entire project was 5 hours, 34 minutes, and 29 seconds. All six flights were highly productive, and all project objectives were achieved. All three of the project objectives were successfully accomplished. The objectives were: demonstration of towed takeoff, climb-out, and separation of the EXD-01 from the towing aircraft; validation of simulation models of the towed aircraft systems; and development of ground and flight procedures for towing and launching a delta-winged airplane configuration safely behind a transport-type aircraft. NASA Dryden served as the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, simulation, instrumentation, range support, research pilots, and chase aircraft for the test series. Dryden personnel also performed the modifications to convert the QF-106 into the piloted EXD-01 aircraft. During the early flight phase of the project, Tracor, Inc. provided maintenance and ground support for the two QF-106 airplanes. The Air Force Flight Test Center (AFFTC), Edwards, California, provided the C-141A transport aircraft for the project, its flight and engineering support, and the aircrew. Kelly Space and Technology provided the modification design and fabrication of the hardware that was installed on the EXD-01 aircraft. Kelly Space and Technology hopes to use the data gleaned from the tow tests to develop a series of low-cost reusable launch vehicles, in particular to gain experience towing delta-wing aircraft having high wing loading, and in general to demonstrate various operational procedures such as ground processing and abort scenarios. The first successful towed flight occurred on December 20, 1997. Prior to this first tow test flight, the C-141A and EXD-01 were used to conduct a series of tethered taxi tests that would validate the tow procedures. Before these tethered taxi tests, a successful joint flight test was conducted in late October 1996, by Dryden, AFFTC, and KST, in which one of the Dryden F-18 chase aircraft flew at various ranges and locations behind the C-141A to define the wake turbulence and wingtip vortex environment. This flight test was replicated in July 1997, with an unmodified QF-106 flight proficiency aircraft.

A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications

NASA Astrophysics Data System (ADS)

Fox, N. J.; Cowley, S. W. H.; Davda, V. N.; Enno, G.; Friis-Christensen, E.; Greenwald, R. A.; Hairston, M. R.; Lester, M.; Lockwood, M.; Lühr, H.; Milling, D. K.; Murphree, J. S.; Pinnock, M.; Reeves, G. D.

1999-11-01

On 7 December 1992, a moderate substorm was observed by a variety of satellites and ground-based instruments. Ionospheric flows were monitored near dusk by the Goose Bay HF radar and near midnight by the EISCAT radar. The observed flows are compared here with magnetometer observations by the IMAGE array in Scandinavia and the two Greenland chains, the auroral distribution observed by Freja and the substorm cycle observations by the SABRE radar, the SAMNET magnetometer array and LANL geosynchronous satellites. Data from Galileo Earth-encounter II are used to estimate the IMF Bz component. The data presented show that the substorm onset electrojet at midnight was confined to closed field lines equatorward of the pre-existing convection reversal boundaries observed in the dusk and midnight regions. No evidence of substantial closure of open flux was detected following this substorm onset. Indeed the convection reversal boundary on the duskside continued to expand equatorward after onset due to the continued presence of strong southward IMF, such that growth and expansion phase features were simultaneously present. Clear indications of closure of open flux were not observed until a subsequent substorm intensification 25 min after the initial onset. After this time, the substorm auroral bulge in the nightside hours propagated well poleward of the pre-existing convection reversal boundary, and strong flow perturbations were observed by the Goose Bay radar, indicative of flows driven by reconnection in the tail.

Carbon fiber reinforcements for sheet molding composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozcan, Soydan; Paulauskas, Felix L.

A method of processing a carbon fiber tow includes the steps of providing a carbon fiber tow made of a plurality of carbon filaments, depositing a sizing composition at spaced-apart sizing sites along a length of the tow, leaving unsized interstitial regions of the tow, and cross-cutting the tow into a plurality of segments. Each segment includes at least a portion of one of the sizing sites and at least a portion of at least one of the unsized regions of the tow, the unsized region including and end portion of the segment.

A Research and Development Strategy for Unexploded Ordnance Sensing

DTIC Science & Technology

1996-04-01

Each lane was carefully traversed with the MK-26 Ordnance Detector (dual fluxgate magnetometer hand-held unit) and the operator hand-excavated any...proton-precessing magnetometers , optically pumped magnetometers , fluxgates magnetometers , and magnetometers based on superconducting quantum...sensitivity better than 0.05 nT, and the optically-pumped magnetometers have sensitivity better than 0.005 nT. Fluxgate magnetometers are based on solid

Directional Stability of Towed Airplanes

NASA Technical Reports Server (NTRS)

Soehne, W.

1956-01-01

So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability. The most important parameters of the flight attitude are the dynamic pressure, the aerodynamic coefficients of the flight attitude, and the climbing angle. Among the configuration properties, the following exert the greatest influence on the stability: the tow-cable length, the tow-cable attachment point, the ratio of the wing loadings of the towing and the towed airplanes, the moments of inertia, and the wing dihedral of the towed airplane. In addition, the size and shape of the towed airplane vertical tail, the vertical tail length, and the fuselage configuration are decisive factors in determining the yawing moment and side force due to sideslip, respectively.

Measurement of the Forces Acting on Gliders in Towed Flight

NASA Technical Reports Server (NTRS)

Klenperer, W B

1940-01-01

The magnitude, the direction, and the fluctuations of tow forces exerted upon gliders by towing them aloft behind an automobile were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests, the glider towing force did not exceed 1.6 of the gross weight of the glider. V-G records obtained during the towed-flight period as well as during the subsequent return glide to earth showed accelerations in the range from 3 to -1 g. The results of preliminary airplane tow tests are also presented.

Long-term vacuum tests of single-mode vertical cavity surface emitting laser diodes used for a scalar magnetometer

NASA Astrophysics Data System (ADS)

Hagen, C.; Ellmeier, M.; Piris, J.; Lammegger, R.; Jernej, I.; Magnes, W.; Murphy, E.; Pollinger, A.; Erd, C.; Baumjohann, W.

2017-11-01

Scalar magnetometers measure the magnitude of the magnetic field, while vector magnetometers (mostly fluxgate magnetometers) produce three-component outputs proportional to the magnitude and the direction of the magnetic field. While scalar magnetometers have a high accuracy, vector magnetometers suffer from parameter drifts and need to be calibrated during flight. In some cases, full science return can only be achieved by a combination of vector and scalar magnetometers.

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Channel Buoy 1 TC. East of Tow Channel Buoy 3 TC. West of Tow Channel Buoy 4 TC. East of Colorado Reef... Tow Channel Buoy 5 TC. East of Tow Channel Buoy 7 TC. West of Petersburg: East of Wrangell Narrows...

Evaluation of Unexploded Ordnance (UXO) Detection Technology at the Standardized UXO Test Sites Aberdeen and Yuma Proving Grounds

DTIC Science & Technology

2007-11-01

TTF Open Field (169) EM EM61MKII cart May. 2006 USGS Blind Grid (805) EM All TEM towed May. 2006 USGS Blind Grid (806) MAG TMGS towed 2.3-1 2.3...0.98 at YPG with a TMGS towed and an TM-4 sling system. f. The only ground penetrating radar system analyzed was demonstrated at the APG blind...MAG858/Cart(312) SCH/Hand(238) SCH/Hand(606) STOLS/Towed(293M) TM4/Sling(362) TM4/Sling(431) TMGS /Towed(806) EM61G822A/Cart(383D) STOLS/Towed(293D

Test report for 120-inch-diameter Solid Rocket Booster (SRB) model tests. [floating and towing characteristics of space shuttle boosters

NASA Technical Reports Server (NTRS)

Jones, W. C.

1973-01-01

The space shuttle solid rocket boosters (SRB's) will be jettisoned to impact in the ocean within a 200-mile radius of the launch site. Tests were conducted at Long Beach, California, using a 12-inch diameter Titan 3C model to simulate the full-scale characteristics of the prototype SRB during retrieval operations. The objectives of the towing tests were to investigate and assess the following: (1) a floating and towing characteristics of the SRB; (2) need for plugging the SRB nozzle prior to tow; (3) attach point locations on the SRB; (4) effects of varying the SRB configuration; (5) towing hardware; and (6) difficulty of attaching a tow line to the SRB in the open sea. The model was towed in various sea states using four different types and varying lengths of tow line at various speeds. Three attach point locations were tested. Test data was recorded on magnetic tape for the tow line loads and for model pitch, roll, and yaw characteristics and was reduced by computer to tabular printouts and X-Y plots. Profile and movie photography provided documentary test data.

Dynamic Towed Array Models and State Estimation for Underwater Target Tracking

DTIC Science & Technology

2013-09-01

adjusting the value of 2q impacts how much non-linear acceleration the model can handle. In [22] it is shown that the best value for 2q is generated...partial_brng_x1 = (-deltaY) / ((deltaY)^2 + (deltaX)^2); partial_brng_x3 = (deltaX) / ((deltaY)^2 + (deltaX)^2); H11 = partial_brng_x1; H13 ...freq_recHat]; H11 = -deltaY/Rng^2; H13 = deltaX/Rng^2; Mult = xhat(5)/Sound_Spd; T1 = Mult*deltaY/Rng^3; T2 = ((deltaVx)*(deltaY)-(deltaVy

Method of forming composite fiber blends

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

1989-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

46 CFR 15.910 - Towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Towing vessels. 15.910 Section 15.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Equivalents § 15.910 Towing vessels. No person may serve as a master or mate (pilot) of any towing vessel...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 4 2014-07-01 2013-07-01 true Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 4 2011-07-01 2011-07-01 false Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

32 CFR 634.50 - Towing and storage.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 4 2013-07-01 2013-07-01 false Towing and storage. 634.50 Section 634.50 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... Towing and storage. (a) Impounded POVs may be towed and stored by either the Services and DLA or a...

Microsatellite Digital Magnetometer SMILE - Present State and Future Trends

NASA Astrophysics Data System (ADS)

Belyayev, Serhiy; Ivchenko, Nickolay

2010-05-01

The fluxgate magnetometers (FGM) are probably the most widespread instruments used onboard spacecrafts for both scientific and service purposes. The recent trend to decrease the weight and size of the spacecrafts requires creating as small as possible but enough sensitive FGM. A joint Swedish-Ukrainian team made the development of such a magnetometer and as the result the Small Magnetometer In Low mass Experiment (SMILE) - a digital fluxgate microsatellite magnetometer - was created [1]. Majority of electronic units of this FGM were combined in a digital integrated circuit - a Field Programmable Gate Array (FPGA). The FPGA provides full processing (determined by a digital correlation algorithm) of amplified and digitized fluxgate sensor output signals and provides both FGM output data and feedback signals. Such digital design makes the instrument very flexible, reduces power consumption and opens possibilities for customization of the operation modes. It allows miniaturizing the electronic unit and, together with the smallest in the world low noise three-component fluxgate sensor with the side dimension of 20 mm and weight about 20 grams only, the small but enough sensitive space qualified FGM is created. SMILE magnetometer was successfully flown onboard the NASA Cascades-2 sounding rocket, and is to fly in the LAPLander package onboard the ESA REXUS-8 student sounding rocket [2]. Unfortunately, such a design of electronic circuit does not allow us to realize all possibilities of the miniature sensor. The separate tests of the sensor with highest-class analog electronics showed that its noise level may be reduced to as low value as 10…15 picoTesla at 1 Hz. Also the use of volume compensation in the sensor provides high geometrical stability of the axes and improved performance compared to component compensated sensors. The measured parameters appear to be comparable or even better than these of best stationary FGM and, if realized in small enough volume and weight, such a sensitive but small FGM could be a good candidate for planned Lunar missions where the weight is the major restriction factor. This stimulated further research in the direction of the analysis and elimination of noise sources of digital design, as well as of the optimization of FGM electronic circuit structure. The description of the obtained results of the electronic unit upgrade and recent FGM model tests are given and future improvement directions are discussed. These works are partially supported by NSAU contract No. 1499. References: 1. Åke Forslund, Serhiy Belyayev, Nickolay Ivchenko, Göran Olsson, Terry Edberg and Andriy Marusenkov, Miniaturized digital fluxgate magnetometer for small spacecraft applications 2008 Meas. Sci. Technol. 19 2. T. Sundberg, N. Ivchenko, D. Borglund, P. Ahlen, M. Gustavsson, C. Jonsson, J. Juhlen, O. Neunet, J. Sandstrom, E. Sund, M. Wartelski, C. Westlund, L. Xin, Small Recoverable Payload for Deployable Sounding Rocket Experiments. ESA Special Publication SP671

Controlled Ascent From the Surface of an Asteroid

NASA Technical Reports Server (NTRS)

Shen, Haijun; Roithmayr, Carlos M.; Cornelius, David M.

2014-01-01

The National Aeronautics and Space Administration (NASA) is currently investigating a conceptual robotic mission to collect a small boulder up to 4 m in diameter resting on the surface of a large Near Earth Asteroid (NEA). Because most NEAs are not well characterized, a great range of uncertainties in boulder mass properties and NEA surface characteristics must be considered in the design of this mission. These uncertainties are especially significant when the spacecraft ascends with the boulder in tow. The most important requirement during ascent is to keep the spacecraft in an upright posture to maintain healthy ground clearances for the two large solar arrays. This paper focuses on the initial stage (the first 50 m) of ascent from the surface. Specifically, it presents a sensitivity study of the solar array ground clearance, control authority, and accelerations at the array tips in the presence of a variety of uncertainties including various boulder sizes, densities, shapes and orientations, locations of the true center of mass, and push-off force distributions. Results are presented, and appropriate operations are recommended in the event some of the off-nominal cases occur.

Method of forming composite fiber blends and molding same

NASA Technical Reports Server (NTRS)

McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor)

1989-01-01

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Towing or pushing loaded buses. 392.63 Section 392... COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.63 Towing or pushing loaded buses. No disabled bus with... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Towing: Gliders and unpowered ultralight... Flight Operations § 91.309 Towing: Gliders and unpowered ultralight vehicles. (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless— (1) The pilot in command of the...

Unexploded Ordnance (UXO) Data Analysis System (DAS). Environmental Quality Technology Program

DTIC Science & Technology

2009-09-01

is comprised of an EMI sensor, cesium (Cs) vapor magnetometer , fluxgate magnetometer , hand-held data acquisition computer, integrated power supply...Geometrics model 823A Cs vapor magnetometer . The fluxgate magnetometer is a Bartington model Mag-3MRN60, three- axis fluxgate magnetometer . The system...9. The ERDC hand-held Dual TFM/EMI with ArcSecond positioning system. During standard usage, the fluxgate magnetometer is used to provide the

Running with horizontal pulling forces: the benefits of towing.

PubMed

Grabowski, Alena M; Kram, Rodger

2008-10-01

Towing, or running with a horizontal pulling force, is a common technique used by adventure racing teams. During an adventure race, the slowest person on a team determines the team's overall performance. To improve overall performance, a faster runner tows a slower runner with an elastic cord attached to their waists. Our purpose was to create and validate a model that predicts the optimal towing force needed by two runners to achieve their best overall performance. We modeled the effects of towing forces between two runners that differ in solo 10-km performance time and/or body mass. We calculated the overall time that could be saved with towing for running distances of 10, 20, and 42.2-km based on equations from previous research. Then, we empirically tested our 10-km model on 15 runners. Towing improved overall running performance considerably and our model accurately predicted this performance improvement. For example, if two runners (a 70 kg runner with a 35 min solo 10-km time and a 70-kg runner with a 50-min solo 10-km time) maintain an optimal towing force throughout a 10-km race, they can improve overall performance by 15%, saving almost 8 min. Ultimately, the race performance time and body mass of each runner determine the optimal towing force.

F-106 tow cable attachment and release mechanism for Eclipse program

NASA Technical Reports Server (NTRS)

1997-01-01

View of the tow cable attachment and release mechanism forward of the cockpit on the QF-106 Eclipse aircraft. This mechanism held and then released the Vectran rope used to tow the QF-106 behind an Air Force C-141A. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Development of Vertical Cable Seismic System (3)

NASA Astrophysics Data System (ADS)

Asakawa, E.; Murakami, F.; Tsukahara, H.; Mizohata, S.; Ishikawa, K.

2013-12-01

The VCS (Vertical Cable Seismic) is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of the survey are from 100m up to 2100m. The target of the survey includes not only hydrothermal deposit but oil and gas exploration. Through these experiments, our VCS data acquisition system has been completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system are available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed another approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In the data acquisition stage, we estimate the position of VCS location with slant ranging method from the sea surface. The deep-towed source or ocean bottom source is estimated by SSBL/USBL. The water velocity profile is measured by XCTD. After the data acquisition, we pick the first break times of the VCS recorded data. The estimated positions of shot points and receiver points in the field include the errors. We use these data as initial guesses, we invert iteratively shot and receiver positions to match the travel time data. After several iterations we could finally estimate the most probable positions. Integration of the constraint of VCS hydrophone positions, such as the spacing is 10m, can accelerate the convergence of the iterative inversion and improve results. The accuracy of the estimated positions from the travel time date is enough for the VCS data processing.

The South American Meridional B-field Array (SAMBA) and Pc4-5 Wave Studies

NASA Astrophysics Data System (ADS)

Sterner, Lt. Nathan; Zesta, Eftyhia; Boudouridis, Athanasios; Moldwin, Mark; Yizengaw, Endawoke; Chi, Peter

The Antarctic continent, the only landmass in the southern polar region, offers the unique opportunity for observations that geomagnetically range from polar latitudes to well into the inner magnetosphere, thus enabling conjugate observations in a wide range of geomagnetic lat-itudes. The SAMBA (South American Meridional B-field Array) chain is a meridional chain of 12 magnetometers, 11 of them at L=1.1 to L=2.5 along the coast of Chile and in the Antarc-tica peninsula, and one auroral station along the same meridian. SAMBA is conjugate to the northern hemisphere MEASURE and McMAC chains, offering unique opportunities for inter-hemispheric studies. In particular, we study asymmetries in the power of ULF waves and the role of the ionosphere in such observed asymmetries. Utilizing conjugate magnetometer stations at L=1.7 and L=2.3, we previously demonstrated that the northern hemisphere consistently shows higher ULF wave power. One possible reason for the asymmetry is solar zenith angles differences with the northern hemisphere station being closer to the ecliptic plain and having a higher power ratio. These hemispheric differences were also observed with TEC measurements indicating that the north and south conjugate ionospheres are similarly asymmetric. The initial study was done with Pc3 waves, which include the resonance frequencies for the flux tubes of our conjugate stations. We now extend the study to Pc4 and Pc5 waves that reach the lower latitudes via different mechanisms and compare these waves to the resonant Pc3 waves.

The South American Meridional B-field Array (SAMBA) and Pc4-5 Wave Studies

NASA Astrophysics Data System (ADS)

Sterner, N. L.; Zesta, E.; Boudouridis, A.; Moldwin, M.; Yizengaw, E.; Chi, P. J.

2010-12-01

The Antarctic continent, the only landmass in the southern polar region, offers the unique opportunity for observations that geomagnetically range from polar latitudes to well into the inner magnetosphere, thus enabling conjugate observations in a wide range of geomagnetic latitudes. The SAMBA (South American Meridional B-field Array) chain is a meridional chain of 12 magnetometers, 11 of them at L=1.1 to L=2.5 along the coast of Chile and in the Antarctica peninsula, and one auroral station along the same meridian. SAMBA is conjugate to the northern hemisphere MEASURE and McMAC chains, offering unique opportunities for inter-hemispheric studies. In particular, we study asymmetries in the power of ULF waves and the role of the ionosphere in such observed asymmetries. Utilizing conjugate magnetometer stations at L=1.7 and L=2.3, we previously demonstrated that the northern hemisphere consistently shows higher ULF wave power. One possible reason for the asymmetry is solar zenith angles differences with the northern hemisphere station being closer to the ecliptic plain and having a higher power ratio. These hemispheric differences were also observed with TEC measurements indicating that the north and south conjugate ionospheres are similarly asymmetric. The initial study was done with Pc3 waves, which include the resonance frequencies for the flux tubes of our conjugate stations. We now extend the study to Pc4 and Pc5 waves that reach the lower latitudes via different mechanisms and compare these waves to the resonant Pc3 waves.

First order reversal curves (FORC) analysis of individual magnetic nanostructures using micro-Hall magnetometry.

PubMed

Pohlit, Merlin; Eibisch, Paul; Akbari, Maryam; Porrati, Fabrizio; Huth, Michael; Müller, Jens

2016-11-01

Alongside the development of artificially created magnetic nanostructures, micro-Hall magnetometry has proven to be a versatile tool to obtain high-resolution hysteresis loop data and access dynamical properties. Here we explore the application of First Order Reversal Curves (FORC)-a technique well-established in the field of paleomagnetism for studying grain-size and interaction effects in magnetic rocks-to individual and dipolar-coupled arrays of magnetic nanostructures using micro-Hall sensors. A proof-of-principle experiment performed on a macroscopic piece of a floppy disk as a reference sample well known in the literature demonstrates that the FORC diagrams obtained by magnetic stray field measurements using home-built magnetometers are in good agreement with magnetization data obtained by a commercial vibrating sample magnetometer. We discuss in detail the FORC diagrams and their interpretation of three different representative magnetic systems, prepared by the direct-write Focused Electron Beam Induced Deposition (FEBID) technique: (1) an isolated Co-nanoisland showing a simple square-shaped hysteresis loop, (2) a more complex CoFe-alloy nanoisland exhibiting a wasp-waist-type hysteresis, and (3) a cluster of interacting Co-nanoislands. Our findings reveal that the combination of FORC and micro-Hall magnetometry is a promising tool to investigate complex magnetization reversal processes within individual or small ensembles of nanomagnets grown by FEBID or other fabrication methods. The method provides sub-μm spatial resolution and bridges the gap of FORC analysis, commonly used for studying macroscopic samples and rather large arrays, to studies of small ensembles of interacting nanoparticles with the high moment sensitivity inherent to micro-Hall magnetometry.

33 CFR 164.76 - Towline and terminal gear for towing alongside and pushing ahead.

Code of Federal Regulations, 2010 CFR

2010-07-01

... towing alongside and pushing ahead. 164.76 Section 164.76 Navigation and Navigable Waters COAST GUARD... Towline and terminal gear for towing alongside and pushing ahead. The owner, master, or operator of each vessel towing alongside or pushing ahead shall ensure that the face wires, spring lines, and push gear...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

46 CFR 11.464 - Requirements for endorsements as master of towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Requirements for endorsements as master of towing....464 Requirements for endorsements as master of towing vessels. (a) If you would like to obtain an endorsement as master of towing vessels with a route listed in column 1 of table 11.464(a) of this section...

Prince William Sound disabled tanker towing study. Part 1. Evaluation of existing equipment, personnel and procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-08-01

The study has been undertaken by the Glosten Associates, Inc., to evaluate the existing capability for emergency towing at Prince William Sound and to examine alternatives that could enhance the escort and assist capabilities for disabled tankers within the waterway from the Alyeska Oil Terminal at the Port of Valdez to the Gulf of Alaska outside Hinchinbrook Entrance. Part 1, reported herein, is an objective evaluation by an experienced salvage towing master of the existing tugs, emergency towing equipment, towing practices, and discussion of alternative tug types.

Recovery of a Temperate Reef Assemblage in a Marine Protected Area following the Exclusion of Towed Demersal Fishing

PubMed Central

Sheehan, Emma V.; Stevens, Timothy F.; Gall, Sarah C.; Cousens, Sophie L.; Attrill, Martin J.

2013-01-01

Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km2 of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as ‘the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls’. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries. PMID:24391841

Recovery of a temperate reef assemblage in a marine protected area following the exclusion of towed demersal fishing.

PubMed

Sheehan, Emma V; Stevens, Timothy F; Gall, Sarah C; Cousens, Sophie L; Attrill, Martin J

2013-01-01

Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2) of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries.

Multi-Sensor Systems Development for UXO Detection and Discrimination: Hand-Held Dual Magnetic/Electromagnetic Induction Sensor

DTIC Science & Technology

2008-04-01

5 Fluxgate magnetometer ... magnetometer into digital format, and transmitted as a single serial data string to log the Cs and fluxgate magnetometer data. After procurement...Hardware The system hardware comprises an EMI sensor, Cs vapor magnetometer , fluxgate magnetometer , hand-held data acquisition computer, integrated

Complete Tri-Axis Magnetometer Calibration with a Gyro Auxiliary

PubMed Central

Yang, Deng; You, Zheng; Li, Bin; Duan, Wenrui; Yuan, Binwen

2017-01-01

Magnetometers combined with inertial sensors are widely used for orientation estimation, and calibrations are necessary to achieve high accuracy. This paper presents a complete tri-axis magnetometer calibration algorithm with a gyro auxiliary. The magnetic distortions and sensor errors, including the misalignment error between the magnetometer and assembled platform, are compensated after calibration. With the gyro auxiliary, the magnetometer linear interpolation outputs are calculated, and the error parameters are evaluated under linear operations of magnetometer interpolation outputs. The simulation and experiment are performed to illustrate the efficiency of the algorithm. After calibration, the heading errors calculated by magnetometers are reduced to 0.5° (1σ). This calibration algorithm can also be applied to tri-axis accelerometers whose error model is similar to tri-axis magnetometers. PMID:28587115

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Persons other than crew on towing, oyster, or fishing... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster dredging and planting, and fishing may be permitted to carry persons in addition to its crew. (b) The...

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Persons other than crew on towing, oyster, or fishing... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster dredging and planting, and fishing may be permitted to carry persons in addition to its crew. (b) The...

49 CFR 393.42 - Brakes required on all wheels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subject to this part is not required to be equipped with brakes if the axle weight of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle. (4) Any full trailer... of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle...

46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Persons other than crew on towing, oyster, or fishing steam vessels. 2.01-50 Section 2.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster...

A simple method for verifying the deployment of the TOMS-EP solar arrays

NASA Technical Reports Server (NTRS)

Koppersmith, James R.; Ketchum, Eleanor

1995-01-01

The Total Ozone Mapping Spectrometer-Earth Probe (TOMS-EP) mission relies upon a successful deployment of the spacecraft's solar arrays. Several methods of verification are being employed to ascertain the solar array deployment status, with each requiring differing amounts of data. This paper describes a robust attitude-independent verification method that utilizes telemetry from the coarse Sun sensors (CSS's) and the three-axis magnetometers (TAM's) to determine the solar array deployment status - and it can do so with only a few, not necessarily contiguous, points of data. The method developed assumes that the solar arrays are deployed. Telemetry data from the CSS and TAM are converted to the Sun and magnetic field vectors in spacecraft body coordinates, and the angle between them is calculated. Deployment is indicated if this angle is within a certain error tolerance of the angle between the reference Sun and magnetic field vectors. Although several other methods can indicate a non-deployed state, with this method there is a 70% confidence level in confirming deployment as well as a nearly 100% certainty in confirming a non-deployed state. In addition, the spacecraft attitude (which is not known during the first orbit after launch) is not needed for this algorithm because the angle between the Sun and magnetic field vectors is independent of the spacecraft attitude. This technique can be applied to any spacecraft with a TAM and with CSS's mounted on the solar array(s).

Full waveform inversion of combined towed streamer and limited OBS seismic data: a theoretical study

NASA Astrophysics Data System (ADS)

Yang, Huachen; Zhang, Jianzhong

2018-06-01

In marine seismic oil exploration, full waveform inversion (FWI) of towed-streamer data is used to reconstruct velocity models. However, the FWI of towed-streamer data easily converges to a local minimum solution due to the lack of low-frequency content. In this paper, we propose a new FWI technique using towed-streamer data, its integrated data sets and limited OBS data. Both integrated towed-streamer seismic data and OBS data have low-frequency components. Therefore, at early iterations in the new FWI technique, the OBS data combined with the integrated towed-streamer data sets reconstruct an appropriate background model. And the towed-streamer seismic data play a major role in later iterations to improve the resolution of the model. The new FWI technique is tested on numerical examples. The results show that when starting models are not accurate enough, the models inverted using the new FWI technique are superior to those inverted using conventional FWI.

Measurement of Sub Degree Angular Carbon Fiber Tow Misalignment

NASA Technical Reports Server (NTRS)

Wilson, William C.; Moore, Jason P.; McCraw, Hunter

2017-01-01

NASA is investigating the use of carbon fiber tow steering to tune aeroelastic characteristics in advanced composite structures. In support of that effort, NASA is also investigating methods of measuring the angle of carbon fiber tows as they are placed. This work presents the results of using microwave reflectometry in the approximately 2 GHz region to measure carbon fiber tow angles at 0.1deg resolution.

An Acoustic Source Reactive to Tow Cable Strum

DTIC Science & Technology

2012-09-21

sound wave radiates from the head mass. Dkt . No. 101720 Application No. ?? REPLACEMENT SHEET? /3 DRAFT 1 CABLE CURVATURE INDUCING LONGITUDINAL...MOTION IDEALIZED TOW CABLE (NO TRANSVERSE VIBRATION) REALISTIC TOW CABLE (INCLUDES TRANSVERSE VIBRATION) DIRECTION OF TOW FIG. 1 (PRIOR ART) Dkt . No...DISPLACEMENT DISPLACEMENT LONGITUDINAL (PRIOR ART) DISPLACEMENT LONGITUDINAL Dkt . No. 101720 Application No. ?? REPLACEMENT SHEET? /3 DRAFT 10 A B B A

Eclipse project QF-106 and C-141A climbs out under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW LAUNCH DEMONSTRATION - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 climbs out under tow by a USAF C-141A on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Status of the Polar Engineering Development Center's (PEDC) Open-Closed Boundary Synoptic Nowcast

NASA Astrophysics Data System (ADS)

Gerrard, A. J.; Kim, H.

2017-12-01

We present the most recent Polar Engineering Development Center (PEDC) developments, specifically the first magnetic-field open-closed boundary (OCB) determination scheme. This scheme is implemented in "near real time" and utilizes data from an array of fluxgate magnetometers that are distributed across the high Antarctic plateau, as per Urban et al. [2012]. This OCB determination enables a high-latitude, synoptic measure of space weather variability that provides for more regional determinations of particle precipitation and related impacts. This methodology therefore supplements exciting "index-based" or empically-based space weather nowcasts currently in use.

SEADYN Analysis of a Tow Line for a High Altitude Towed Glider

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1996-01-01

The concept of using a system, consisting of a tow aircraft, glider and tow line, which would enable subsonic flight at altitudes above 24 km (78 kft) has previously been investigated. The preliminary results from these studies seem encouraging. Under certain conditions these studies indicate the concept is feasible. However, the previous studies did not accurately take into account the forces acting on the tow line. Therefore in order to investigate the concept further a more detailed analysis was needed. The code that was selected was the SEADYN cable dynamics computer program which was developed at the Naval Facilities Engineering Service Center. The program is a finite element based structural analysis code that was developed over a period of 10 years. The results have been validated by the Navy in both laboratory and at actual sea conditions. This code was used to simulate arbitrarily-configured cable structures subjected to excitations encountered in real-world operations. The Navy's interest was mainly for modeling underwater tow lines, however the code is also usable for tow lines in air when the change in fluid properties is taken into account. For underwater applications the fluid properties are basically constant over the length of the tow line. For the tow aircraft/glider application the change in fluid properties is considerable along the length of the tow line. Therefore the code had to be modified in order to take into account the variation in atmospheric properties that would be encountered in this application. This modification consisted of adding a variable density to the fluid based on the altitude of the node being calculated. This change in the way the code handled the fluid density had no effect on the method of calculation or any other factor related to the codes validation.

Closeup of QF-106 release hook for Eclipse program

NASA Technical Reports Server (NTRS)

1997-01-01

View of the release hook on the QF-106 that allowed the pilot to release the tow rope extending from the C-141A tow plane in the Eclipse project. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse program C-141A aircraft

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. The project used a QF-106 interceptor aircraft to simulate a future orbiter, which would be towed to a high altitude and released to fire its own engines and carry a payload into space. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Flight performance of the Pioneer Venus Orbiter solar array

NASA Technical Reports Server (NTRS)

Goldhammer, L. J.; Powe, J. S.; Smith, Marcie

1987-01-01

The Pioneer Venus Orbiter (PVO) solar panel power output capability has degraded much more severely than has the power output capability of solar panels that have operated in earth-orbiting spacecraft for comparable periods of time. The incidence of solar proton events recorded by the spacecraft's scientific instruments accounts for this phenomenon only in part. It cannot explain two specific forms of anomalous behavior observed: 1) a variation of output per spin with roll angle, and 2) a gradual degradation of the maximum output. Analysis indicates that the most probable cause of the first anomaly is that the solar cells underneath the spacecraft's magnetometer boom have been damaged by a reverse biasing of the cells that occurs during pulsed shadowing of the cells by the boom as the spacecraft rotates. The second anomaly might be caused by the effects on the solar array of substances from the upper atmosphere of Venus.

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2012 CFR

2012-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2013 CFR

2013-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2014 CFR

2014-01-01

... wheel to which the load is applied. Enough airplane inertia to achieve equilibrium must be applied. (ii) The loads must be reacted by airplane inertia. (d) The prescribed towing loads are as follows: Tow...

Lesson learned from monitoring the environmental effects of construction of the first offshore wind farm in the US

NASA Astrophysics Data System (ADS)

Miller, J.; Potty, G. R.; King, J. W.; Gallien, D. R.; Khan, A. A.; Vigness Raposa, K.; Giard, J. L.; Frankel, A. S.; Mason, T.; Popper, A. N.; Hawkins, A. D.; Crocker, S. E.

2016-02-01

Noise radiation from pile driving activities were monitored using multiple sensors during the construction of the USA's first offshore wind farm located 3 nm off Block Island, RI. The 30-megawatt Block Island Wind Farm (BIWF) consists of five turbines in water depths of approximately 30 m and is scheduled to be online in 2016. The substructure for these turbines consists of jacket type construction with piles driven to pin the structure to the seabed. Pile driving operations generate intense sound, impulsive in nature at close range, which radiates into the surrounding air, water and sediment. The underwater acoustic measurement platforms consisted of a towed array consisting of eight hydrophones, two fixed moorings with four hydrophones each, a fixed sensor package for measuring particle velocity, and boat-deployed dipping hydrophones. The hydrophone array was towed from a position 1 km from the pile driving location to 15 km distance from the construction. The fixed moorings were deployed at 10 km and 15 km from the pile location. The fixed moorings consisted of four hydrophones each at depths of 10, 15, 20 and 25 m. Near field measurements of the underwater acoustic signals from the pile driving were collected with a tetrahedral array deployed at 500 m from the pile driving location about 1 m above the seabed. The boat-deployed dipping hydrophones sampled the acoustic field at locations from 0.5 km to 20 km from the pile driving locations. Based on these acoustic measurements and propagation modeling, the acoustic pressure field as a function of range and depth from the pile is estimated. The transition from fast-rise-time impulsive signals at close range to slow-rise-time non-impulsive signals at longer ranges will be addressed. This study will provide the required information to qualify the different zones of potential marine mammal effects (zones of injury, behavioral effects etc.) and to estimate exposure to fishes and other species. [Work supported by Bureau of Ocean Energy Management (BOEM)

Man-Portable Simultaneous Magnetometer and EM System (MSEMS)

DTIC Science & Technology

2008-12-01

limited to cesium vapor magnetometers outputting a Larmor signal. It cannot, as presently configured, be used with less expensive fluxgate magnetometers ...pulses to convert the frequency-based Larmor signal into nT. A fluxgate magnetometer does not employ the resonance mechanism of an alkali vapor...Simultaneous Magnetometer and EM System (MSEMS) December 2008 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the

Low Cost, Low Power, High Sensitivity Magnetometer

DTIC Science & Technology

2008-12-01

which are used to measure the small magnetic signals from brain. Other types of vector magnetometers are fluxgate , coil based, and magnetoresistance...concentrator with the magnetometer currently used in Army multimodal sensor systems, the Brown fluxgate . One sees the MEMS fluxgate magnetometer is...Guedes, A.; et al., 2008: Hybrid - LOW COST, LOW POWER, HIGH SENSITIVITY MAGNETOMETER A.S. Edelstein*, James E. Burnette, Greg A. Fischer, M.G

2002 Airborne Geophysical Survey at Pueblo of Laguna Bombing Targets, New Mexico. Revision 3

DTIC Science & Technology

2005-10-01

conducted and results evaluated. The eight cesium magnetometers , GPS systems (positioning and attitude), fluxgate magnetometers , data recording...Accurate positioning requires a correction for this lag. Time lags between the magnetometers , fluxgate magnetometer , and GPS signals were measured by...between magnetometers and fluxgate ); An initial check flight after installation. Under the category of data QA/QC: An extensive test flight to

Investigations and Tests in the Towing Basin at Guidonia

NASA Technical Reports Server (NTRS)

Cremona, C

1939-01-01

The experimental methods at the Guidonia towing basin are discussed including specifications. Some of the components examined are the bridge towing carriage, side towing carriage, catapult installation, and dynamometer systems. Tests were performed on hulls and floats, as well as motor boats and torpedo shaped bodies. Theoretical investigations were also performed to determine pressure distributions on geometrically simple bodies, propagation of small wave motions, and planing and submerged surfaces.

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2010 CFR

2010-01-01

... static positions; and (3) With W T as the design ramp weight, the towing load, F TOW, is— (i) 0.3 W T for W T less than 30,000 pounds; (ii) (6W T+450,000)/7 for W T between 30,000 and 100,000 pounds; and (iii) 0.15 W T for W T over 100,000 pounds. (b) For towing points not on the landing gear but near the...

14 CFR 25.509 - Towing loads.

Code of Federal Regulations, 2011 CFR

2011-01-01

... static positions; and (3) With W T as the design ramp weight, the towing load, F TOW, is— (i) 0.3 W T for W T less than 30,000 pounds; (ii) (6W T+450,000)/7 for W T between 30,000 and 100,000 pounds; and (iii) 0.15 W T for W T over 100,000 pounds. (b) For towing points not on the landing gear but near the...

A Antarctic Magnetometer Chain Along the Cusp Latitude: Preliminary Results

NASA Astrophysics Data System (ADS)

Liu, Y.

2016-12-01

A magnetometer chain from Zhongshan Station to Dome-A in Antarctica has been established since February 2009, consisting in five fluxgate magnetometers, with one regular magnetometer at Zhongshan Station and four low power magnetometers along the cusp latitude in the southern hemisphere, over a distance of 1260 Km. It is one part of the magnetometer network in Antarctic continent, filling the void area for magnetic observation over east-southern Antarctica, greatly enlarging the coverage of the Zhongshan Station. It is also magnetically conjugated with Svalbard region in the Arctic, with a leg extending to DNB in east coast Greenland. Conjunction observation among these magnetometers could provide excellent tracing of series of the typical space physical phenomena such as FTE, TCV, MIE, ULF waves, etc.

Winding a Long Coil with a Pre-Programmed Turns Density Variation

DTIC Science & Technology

1975-05-27

turns den- sity is to follow. A machine having this capability is needed to provide a towed ELF loop antenna with the smoothly tapered sensitivity...Introduction A submarine towed ELF loop antenna vibrates longitudinally and trans- versely during towing. The vibration is driven by the fluctuating surface...in attaining the smoothly varying turns density required for the signal winding of a towed ELF loop antenna . Acknowledgments Thanks are due to John

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false May I use a vessel to tow a...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false May I use a vessel to tow a...

Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows

NASA Technical Reports Server (NTRS)

Kohlman, Lee W.

2013-01-01

Toughening and other property enhancements of composite materials are typically implemented by-modifying the bulk properties of the constituents, either the fiber or matrix materials. This often leads to difficulties in processing and higher material costs. Many composites consist of tows or yarns (thousands of individual fibers) that are either filament wound or processed into a fabric by weaving or braiding. The matrix material can be added to the tow or fabric before final processing, resulting in a prepreg material, or infused into the fiber material during final processing by a variety of methods. By using a direct electrospun deposition method to apply thermoplastic nanofiber to the surface of the tows, the tow-tow interface in the resulting composite can be modified while using otherwise conventional materials and handling processes. Other materials of interest could also be incorporated into the electrospun precursor.

A Merged Dataset for Solar Probe Plus FIELDS Magnetometers

NASA Astrophysics Data System (ADS)

Bowen, T. A.; Dudok de Wit, T.; Bale, S. D.; Revillet, C.; MacDowall, R. J.; Sheppard, D.

2016-12-01

The Solar Probe Plus FIELDS experiment will observe turbulent magnetic fluctuations deep in the inner heliosphere. The FIELDS magnetometer suite implements a set of three magnetometers: two vector DC fluxgate magnetometers (MAGs), sensitive from DC- 100Hz, as well as a vector search coil magnetometer (SCM), sensitive from 10Hz-50kHz. Single axis measurements are additionally made up to 1MHz. To study the full range of observations, we propose merging data from the individual magnetometers into a single dataset. A merged dataset will improve the quality of observations in the range of frequencies observed by both magnetometers ( 10-100 Hz). Here we present updates on the individual MAG and SCM calibrations as well as our results on generating a cross-calibrated and merged dataset.

Eclipse program C-141A aircraft

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wind loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Frequency domain and full waveform time domain inversion of ground based magnetometer, electrometer and incoherent scattering radar arrays to image strongly heterogenous 3-D Earth structure, ionospheric structure, and to predict the intensity of GICs in the power grid

NASA Astrophysics Data System (ADS)

Schultz, A.; Imamura, N.; Bonner, L. R., IV; Cosgrove, R. B.

2016-12-01

Ground-based magnetometer and electrometer arrays provide the means to probe the structure of the Earth's interior, the interactions of space weather with the ionosphere, and to anticipate the intensity of geomagnetically induced currents (GICs) in power grids. We present a local-to-continental scale view of a heterogeneous 3-D crust and mantle as determined from magnetotelluric (MT) observations across arrays of ground-based electric and magnetic field sensors. MT impedance tensors describe the relationship between electric and magnetic fields at a given site, thus implicitly they contain all known information on the 3-D electrical resistivity structure beneath and surrounding that site. By using multivariate transfer functions to project real-time magnetic observatory network data to areas surrounding electric power grids, and by projecting those magnetic fields through MT impedance tensors, the projected magnetic field can be transformed into predictions of electric fields along the path of the transmission lines, an essential element of predicting the intensity of GICs in the grid. Finally, we explore GICs, i.e. Earth-ionosphere coupling directly in the time-domain. We consider the fully coupled EM system, where we allow for a non-stationary ionospheric source field of arbitrary complexity above a 3-D Earth. We solve the simultaneous inverse problem for 3-D Earth conductivity and source field structure directly in the time domain. In the present work, we apply this method to magnetotelluric data obtained from a synchronously operating array of 25 MT stations that collected continuous MT waveform data in the interior of Alaska during the autumn and winter of 2015 under the footprint of the Poker Flat (Alaska) Incoherent Scattering Radar (PFISR). PFISR data yield functionals of the ionospheric electric field and ionospheric conductivity that constrain the MT source field. We show that in this region conventional robust MT processing methods struggle to produce reliable MT response functions at periods much greater than about 2,000 s, a consequence, we believe, of the complexity of the ionospheric source fields in this high latitude setting. This provides impetus for direct waveform inversion methods that dispense with typical parametric assumptions made about the MT source fields.

National Geomagnetism Program: Current Status & Five-Year Plan, 2006-2010

USGS Publications Warehouse

Love, Jeffrey J.

2006-01-01

Executive Summary: The U.S. Geological Survey's Geomagnetism Program serves the scientific community and the broader public by collecting and distributing magnetometer data from an array of ground-based observatories and by conducting scientific analysis on those data. Preliminary, variational time-series can be collected and distributed in near-real time, while fully calibrated, absolute time-series are distributed after processing. The data are used by the civilian and military parts of the Federal Government, by private industry, and by academia, for a wide variety of purposes of both immediately practical importance and long-term scientific interest, including space-weather diagnosis and related hazard mitigation, mapping of the magnetic field and measurement of its activity, and research on the nature of the Earth's interior and the near-Earth space environment. This document reviews the current status of the Program, in terms of its situation within the Government and within the scientific community; summarizes the Program's operations, its staffing situation, and its facilities; describes the diversity of uses of Program magnetometer data; and presents a plan for the next 5 years for enhancing the Program's data-based services, developing products, and conducting scientific research.

Possible tectonomagnetic effect observed from mid-1989, to mid-1990, in Long Valley Caldera, California

USGS Publications Warehouse

Mueller, R.J.; Johnston, M.J.S.; Langbein, J.O.

1991-01-01

Precise measurements of local magnetic fields have been obtained with a differentially connected array of three proton magnetometers in the Long Valley Caldera region since 1984. After correction for secular variation, it is apparent that an anomalous 2 nT decrease in the magnetic field occurred from mid-1989 to mid-1990 at the magnetometer located closed to the center of the resurgent dome inside the caldera. During this period a significant increase in geodetic strain rate of 8.5 ppm/a was observed on the two-color geodimeter network within the caldera from October, 1989, to mid-1990 and a dramatic increase in seismic activity occurred from December, 1989 to July, 1990. A simple dilatational point-source model with pressure increasing by 52 Mpa from October 1989 to August 1990 at a depth of about 7 km beneath the center of the resurgent dome can be fit to the strain data. Magnetic, seismic and geodetic data suggest that an episode of active magmatic intrusion occurred from late 1989 to mid-1990 at a depth of about 7-8 km beneath the resurgent dome within the caldera. -from Authors

Evaluating Detection and Estimation Capabilities of Magnetometer-Based Vehicle Sensors

DTIC Science & Technology

2012-05-01

fluxgate magnetometers whose operating characteristics are well documented [1, 2]. Such magnetometers measure two perpendicular magnetic components of...of surveillance scenarios. As part of that work, this analysis focuses on UGS utilizing of two-axis fluxgate magnetometers . Two MOPs are 12 -60 -40 -20...Proceedings of the IEEE, 78(6):973–989, June 1990. [2] E. M. Billingsley and S. W. Billingsley. Fluxgate magnetometers . Proceedings of the IEEE, 5090(194

Non-consent towing cost study in Utah.

DOT National Transportation Integrated Search

2015-01-01

This study was conducted on behalf of the UDOT Motor Carrier Division at the request of the towing industry in : Utah to evaluate the maximum allowable rates for Non-Consent Towing. The objectives were to: 1-Evaluate : the Current Maximum...

Comparison of Temporal Parameters of Swimming Rescue Elements When Performed Using Dolphin and Flutter Kick with Fins - Didactical Approach

PubMed Central

Rejman, Marek; Wiesner, Wojciech; Silakiewicz, Piotr; Klarowicz, Andrzej; Abraldes, J. Arturo

2012-01-01

The aim of this study was an analysis of the time required to swim to a victim and tow them back to shore, while perfoming the flutter-kick and the dolphin-kick using fins. It has been hypothesized that using fins while using the dolphin-kick when swimming leads to reduced rescue time. Sixteen lifeguards took part in the study. The main tasks performed by them, were to approach and tow (double armpit) a dummy a distance of 50m while applying either the flutter-kick, or the dolphin-kick with fins. The analysis of the temporal parameters of both techniques of kicking demonstrates that, during the approach to the victim, neither the dolphin (tmean = 32.9s) or the flutter kick (tmean = 33.0s) were significantly faster than the other. However, when used for towing a victim the flutter kick (tmean = 47.1s) was significantly faster when compared to the dolphin-kick (tmean = 52.8s). An assessment of the level of technical skills in competitive swimming, and in approaching and towing the victim, were also conducted. Towing time was significantly correlated with the parameter that linked the temporal and technical dimensions of towing and swimming (difference between flutter kick towing time and dolphin-kick towing time, 100m medley time and the four swimming strokes evaluation). No similar interdependency has been discovered in flutter kick towing time. These findings suggest that the dolphin-kick is a more difficult skill to perform when towing the victim than the flutter-kick. Since the hypothesis stated was not confirmed, postulates were formulated on how to improve dolphin-kick technique with fins, in order to reduce swimming rescue time. Key points The source of reduction of swimming rescue time was researched. Time required to approach and to tow the victim while doing the flutter kick and the dolphin-kick with fins was analyzed. The propulsion generated by dolphin-kick did not make the approach and tow faster than the flutter kick. More difficult skill to realize of dolphin-kick than the flutter-kick was postulated. The criteria for how improve dolphin kick technique with fins were formulated. PMID:24150079

First order reversal curves (FORC) analysis of individual magnetic nanostructures using micro-Hall magnetometry

NASA Astrophysics Data System (ADS)

Pohlit, Merlin; Eibisch, Paul; Akbari, Maryam; Porrati, Fabrizio; Huth, Michael; Müller, Jens

2016-11-01

Alongside the development of artificially created magnetic nanostructures, micro-Hall magnetometry has proven to be a versatile tool to obtain high-resolution hysteresis loop data and access dynamical properties. Here we explore the application of First Order Reversal Curves (FORC)—a technique well-established in the field of paleomagnetism for studying grain-size and interaction effects in magnetic rocks—to individual and dipolar-coupled arrays of magnetic nanostructures using micro-Hall sensors. A proof-of-principle experiment performed on a macroscopic piece of a floppy disk as a reference sample well known in the literature demonstrates that the FORC diagrams obtained by magnetic stray field measurements using home-built magnetometers are in good agreement with magnetization data obtained by a commercial vibrating sample magnetometer. We discuss in detail the FORC diagrams and their interpretation of three different representative magnetic systems, prepared by the direct-write Focused Electron Beam Induced Deposition (FEBID) technique: (1) an isolated Co-nanoisland showing a simple square-shaped hysteresis loop, (2) a more complex CoFe-alloy nanoisland exhibiting a wasp-waist-type hysteresis, and (3) a cluster of interacting Co-nanoislands. Our findings reveal that the combination of FORC and micro-Hall magnetometry is a promising tool to investigate complex magnetization reversal processes within individual or small ensembles of nanomagnets grown by FEBID or other fabrication methods. The method provides sub-μm spatial resolution and bridges the gap of FORC analysis, commonly used for studying macroscopic samples and rather large arrays, to studies of small ensembles of interacting nanoparticles with the high moment sensitivity inherent to micro-Hall magnetometry.

Carbon Fiber TOW Angle Determination Using Microwave Reflectometry

NASA Technical Reports Server (NTRS)

Wilson, William C.; Moore, Jason P.; Juarez, Peter D.

2016-01-01

NASA's Advanced Composites Project is investigating technologies that increase automated remote inspection of aircraft composite structures. Therefore, microwave Frequency Domain Reflectometry (FDR) is being investigated as a method of enabling rapid remote inspection of angular orientation of the tow using microwave radiation. This work will present preliminary data demonstrating that frequency shifts in the reflection spectrum of a carbon fiber tow sample are indicative of the angle of the tow with respect to an interrogating antenna's linear polarized output.

System Applies Polymer Powder To Filament Tow

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Snoha, John J.; Marchello, Joseph M.

1993-01-01

Polymer powder applied uniformly and in continuous manner. Powder-coating system applies dry polymer powder to continuous fiber tow. Unique filament-spreading technique, combined with precise control of tension on fibers in system, ensures uniform application of polymer powder to web of spread filaments. Fiber tows impregnated with dry polymer powders ("towpregs") produced for preform-weaving and composite-material-molding applications. System and process valuable to prepreg industry, for production of flexible filament-windable tows and high-temperature polymer prepregs.

Design and Analysis of Tow-Steered Composite Shells Using Fiber Placement

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey

2008-01-01

In this study, a sub-scale advanced composite shell design is evaluated to determine its potential for use on a future aircraft fuselage. Two composite shells with the same nominal 8-ply [+/-45/+/-Theta](sub s) layup are evaluated, where Theta indicates a tow-steered ply. To build this shell, a fiber placement machine would be used to steer unidirectional prepreg tows as they are placed around the circumference of a 17-inch diameter right circular cylinder. The fiber orientation angle varies continuously from 10 degrees (with respect to the shell axis of revolution) at the crown, to 45 degrees on the side, and back to 10 degrees on the keel. All 24 tows are placed at each point on every fiber path in one structure designated as the shell with overlaps. The resulting pattern of tow overlaps causes the laminate thickness to vary between 8 and 16 plies. The second shell without tow overlaps uses the capability of the fiber placement machine to cut and add tows at any point along the fiber paths to fabricate a shell with a nearly uniform 8-ply laminate thickness. Issues encountered during the design and analysis of these shells are presented and discussed. Static stiffness and buckling loads of shells with tow-steered layups are compared with the performance of a baseline quasi-isotropic shell using both finite element analyses and classical strength of materials theory.

Influence of elliptical structure on impinging-jet-array heat transfer performances

NASA Astrophysics Data System (ADS)

Arjocu, Simona C.; Liburdy, James A.

1997-11-01

A three-by-three square array of submerged, elliptic, impinging jets in water was used to study the heat transfer distribution in the cooling process of a constant heat flux surface. Tow jet aspect ratios were used, 2 and 3, both with the same hydraulic diameter. The array was tested at Reynolds numbers from 300 to 1500 and impinging distances of 1 to 5 hydraulic diameters. Thermochromic liquid crystals wee used to map the local heat transfer coefficient using a transient method, while the jet temperature was kept constant. The liquid crystal images were recorded through an optical fiber coupled with a CCD camera and a frame grabber and analyzed based on an RGB-temperature calibration technique. The results are reported relative to the unit cell that is used to delimitate the central jet. The heat transfer variation is shown to depend on the impingement distance and Reynolds number. The elliptic jets exhibit axis switching, jet column instability and jet swaying. All of these mechanisms affect the enhancement of the heat transfer rate and its distribution. The results are compared in terms of average and local heat transfer coefficients, for both major and minor planes for the two jet aspect ratios.

Integrated induction coil and fluxgate magnetometers for EM analysis and monitoring

NASA Astrophysics Data System (ADS)

Hanstein, T.; Strack, K.; Jiang, J.

2013-12-01

The concept of a full field array electromagnetic system is an ideal tool to support hydrocarbon and geothermal E & P as well as various engineering monitoring applications. Some of the key questions are defining the reservoir, mapping of the fractures and reservoir depletion monitoring. The reservoirs are all too often relative thin and give an anomalous electromagnetic (EM) response, which is often small in amplitude and challenging for the EM measuring system. A digital fluxgate magnetometer (32-bit) is connected to the KMS magnetotelluric acquisition system with analogue induction coils and electrodes to extend the range of application of a single recording site. Since the noise level is above that of the induction coil for periods shorter than 20 s, the apparent resistivity is biased. For longer periods the apparent resistivity is consistent and eventually better than the induction coil. However, phase and tipper are not biased and agree well with the induction data even for shorter periods. This allows us to develop algorithms that significantly extend the range of application of the fluxgate beyond what was done in the past. The highest frequency of the fluxgate magnetometer is about 180 Hz and the hightest sampling of the FG-board is 4 kHz.The different induction coils and fluxgate magnetometer have intensively been tested in the magnetic chamber and at the field test site near Houston for noise performance by parallel recordings. They show that even in an environment with high cultural noise, the specification can be met. In Northeast China, a 30-day monitoring test with MT was carried out for seismologic applications. Acquisitition schedule included different recordings times and sampling rates. Daily, the data was collected and processed via the internet from either Europe or the US. Even with long recording, we still had to select the time windows for data averaging and coherences are not a good threshhold criteria in this case. During another MT sounding in India, an earthquake with magnitude 5 at a distance of about 200 km was recorded. The event is very strong in amplitude and visible in all magnetic and electric field components.

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... the Commandant; (2) A manually-operated clean-agent system that satisfies the National Fire Protection... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

GLORIA II Sonograph Mosaic of the Western U.S. Exclusive Economic Zone

NASA Astrophysics Data System (ADS)

Cacchione, D. A.; Drake, D. E.; Edwards, B.; Field, M.; Gardner, J.; Hampton, M.; Karl, H.; McCulloch, D.; Kenyon, N.; Masson, D.

In 1983 the United States declared sovereign rights and jurisdiction over living and nonliving resources in an area extending 200 nautical miles (370 km) seaward from its shores. In response to the establishment of this Exclusive Economic Zone (EEZ), the U.S. Geological Survey (USGS) has implemented a program, called EEZ-Scan, to systematically map the EEZ, using the Geological Long- Range Inclined ASDIC (GLORIA) II longrange side scan sonar system developed by the Institute of Oceanographic Sciences (IOS) of Great Britain [Somers et al, 1978]. The first part of the EEZ-Scan field program was completed in the summer of 1984, when USGS and IOS scientists surveyed the EEZ off the western conterminous United States aboard the British research vessel Farnella (Figure 1). The west coast survey, requiring 96 days of ship time and four separate legs, has resulted in virtually total sonograph coverage of the sea floor from the continental shelf break to the 200-nautical mile limit between the Mexican and Canadian borders, an area of about 850,000 km2 . Other data collected on the cruises included two-channel digital seismic reflection and 3.5-kHz highresolution and 10-kHz bathymetric profiles, as well as towed magnetometer data along approximately 20,000 km of trackline spaced nominally at 30-km intervals.

Feasibility of Using the Space Shuttle to Conduct Global Geomagnetic Surveys (Phase I - Retrievable Probes)

DTIC Science & Technology

1985-07-01

Datatape Division 4-1 5.0 REFERENCES Acuna, M.H. et. al., The MAGSAT Vector Magnetometer - A Precision Fluxgate Magnetometer for the Measurement of the...charting would consist of a triaxial, mutually orthogonal fluxgate magnetometer and an absolute scalar magnetometer to check the flux- gates drift...While space-ready, triaxial fluxgate magnetometers are not an off-the-shelf item, their design concepts are well understood. Their resolution of less

First results from experiment in South China Sea using marine controlled source electromagnetic

NASA Astrophysics Data System (ADS)

Li, Yuan; Wang, Lipeng; Deng, Ming

2016-04-01

We concentrated on the use of marine controlled-source electromagnetic (CSEM) sounding with a horizontal electric dipole source towed close to the seafloor and receivers anchored on the seafloor. We applied the CSEM method in South China Sea for the first time in 2014, which not only test the application of our instrument, but also test our data processing method. Electromagnetic fields transmitted by a towed electric dipole source in deep sea were measured by a linear array of six seafloor receivers, positioned 600 meter (m) apart. Our results provided two highly resistivity layers beneath the survey line and the gas hydrate saturation profile associated with the anomalous resistivity. In the letter, we discussed some anomalous layers during the interpretation steps. The most plausible explanation of the first resistivity layer anomalies is that large amounts of gas hydrate have accumulated at 200 m depth below the seep sites, and the second layers is considerable volumes of gas hydrate have accumulated the seafloor at survey line according to the conceptual model, during the resistivity compared with other evidence like seismic and well data from the same survey. We should try other observation like heat flow, geochemical or other evidence to test the statement in the future.

The ecosystem service value of living versus dead biogenic reef

NASA Astrophysics Data System (ADS)

Sheehan, E. V.; Bridger, D.; Attrill, M. J.

2015-03-01

Mixed maerl beds (corralline red algae) comprise dead thalli with varying amounts of live maerl fragments, but previously it was not known whether the presence of the live maerl increases the ecosystem service 'habitat provision' of the dead maerl for the associated epibenthos. A 'flying array' towed sled with high definition video was used to film transects of the epibenthos in dead maerl and mixed maerl beds in two locations to the north and south of the English Channel (Falmouth and Jersey). Mixed maerl beds supported greater number of taxa and abundance than dead beds in Falmouth, while in Jersey, mixed and dead beds supported similar number of taxa and dead beds had a greater abundance of epifauna. Scallops tended to be more abundant on mixed beds than dead beds. Tube worms were more abundant on mixed beds in Falmouth and dead beds in Jersey. An increasing percentage occurrence of live maerl thalli correlated with increasing number of taxa in Falmouth but not Jersey. It was concluded that while live thalli can increase the functional role of dead maerl beds for the epibenthos, this is dependent on location and response variable. As a result of this work, maerl habitat in SE Jersey has been protected from towed demersal fishing gear.

Eclipse project closeup of QF-106 under tow on takeoff on first flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

OFF THE GROUND - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 lifts off under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse project closeup of QF-106 under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

The Kelly Space and Technology (KST)/USAF/NASA Eclipse project's modified QF-106 is shown under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, is hosting the project, providing engineering and facility support as well as the project pilot, Mark Stucky. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Simulation of Complex Cracking in Plain Weave C/SiC Composite under Biaxial Loading

NASA Technical Reports Server (NTRS)

Cheng, Ron-Bin; Hsu, Su-Yuen

2012-01-01

Finite element analysis is performed on a mesh, based on computed geometry of a plain weave C/SiC composite with assumed internal stacking, to reveal the pattern of internal damage due to biaxial normal cyclic loading. The simulation encompasses intertow matrix cracking, matrix cracking inside the tows, and separation at the tow-intertow matrix and tow-tow interfaces. All these dissipative behaviors are represented by traction-separation cohesive laws. Not aimed at quantitatively predicting the overall stress-strain relation, the simulation, however, does not take the actual process of fiber debonding into account. The fiber tows are represented by a simple rule-of-mixture model where the reinforcing phase is a hypothetical one-dimensional material. Numerical results indicate that for the plain weave C/SiC composite, 1) matrix-crack initiation sites are primarily determined by large intertow matrix voids and interlayer tow-tow contacts, 2) the pattern of internal damage strongly depends on the loading path and initial stress, 3) compressive loading inflicts virtually no damage evolution. KEY WORDS: ceramic matrix composite, plain weave, cohesive model, brittle failure, smeared crack model, progressive damage, meso-mechanical analysis, finite element.

A phaseonium magnetometer: A new optical magnetometer based on index enhanced media

NASA Technical Reports Server (NTRS)

Scully, Marlan O.; Fleischauer, Michael; Graf, Martin

1993-01-01

An optical magnetometer based on quantum coherence and interference effects in atoms is proposed. The sensitivity of this device is potentially superior to the present state-of-the-art devices. Optimum operating conditions are derived, and a comparison to standard optical pumping magnetometers is made.

Response of humpback whales (Megaptera novaeangliae) to ramp-up of a small experimental air gun array.

PubMed

Dunlop, Rebecca A; Noad, Michael J; McCauley, Robert D; Kniest, Eric; Slade, Robert; Paton, David; Cato, Douglas H

2016-02-15

'Ramp-up', or 'soft start', is a mitigation measure used in seismic surveys and involves increasing the radiated sound level over 20-40 min. This study compared the behavioural response in migrating humpback whales to the first stages of ramp-up with the response to a 'constant' source, 'controls' (in which the array was towed but not operated) with groups in the absence of the source vessel used as the 'baseline'. Although the behavioural response, in most groups, resulted in an increase in distance from the source (potential avoidance), there was no evidence that either 'ramp-up' or the constant source at a higher level was superior for triggering whales to move away from the source vessel. 'Control' groups also responded suggesting the presence of the source vessel had some effect. However, the majority of groups appeared to avoid the source vessel at distances greater than the radius of most mitigation zones. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the Viking-Cives tow plow.

DOT National Transportation Integrated Search

2009-05-01

In early February, 2009, the Maine Department of Transportation (MaineDOT) entered into an agreement : with Viking-Cives USA to evaluate the Viking-Cives Tow Plow. MaineDOT agreed to evaluate the Tow : Plow for the remainder of the 2008-2009 winter s...

77 FR 49002 - Towing Safety Advisory Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

... concurrent meetings of the four subcommittees, ``Recommendations for the Prevention of Towing Vessel Crewmember Falls Overboard'', ``Review and recommendations for the revision of NVIC 1-95, Voluntary Training Standards for Entry-Level Personnel on Towing Industry Vessels'', ``Recommendations for the Enhancement of...

Method and apparatus for deregistering multi-filament tow and product thereof

DOEpatents

Lukhard, Craig R.; Potter, Jerry F.; Todd, Maurice C.

1995-01-01

A method and apparatus for deregistering drawn crimped nylon multifilament tow includes the steps of stretching the tow under constant controlled tension at a temperature below the glass transition temperature of the nylon. The apparatus includes means for sensing the tension of the tow between the feed and draw sections of a stretching device and producing a signal representative of the tension sensed and a controller for changing the speed of the draw section actuated by said signal.

Development of new exploration tools for seabed mineral resources - Result of R/V YOKOSUKA research cruise YK09-09 -

NASA Astrophysics Data System (ADS)

Harada, M.; Sayanagi, K.; Kasaya, T.; Sawa, T.; Goto, T.; Tada, N.; Ichihara, H.; Asada, M.; Nakajima, T.; Isezaki, N.

2009-12-01

Detailed information on subsurface structure under seafloor is necessary for the estimation of seabed resources such as the hydrothermal deposit and methane hydrate. Although advantages of geophysical exploration near seafloor are expected for the seabed resource survey, efficient method has not been well-established. The authors started a project to develop exploration tools for seabed resources under the financial support of MEXT-Japan. We carry out research and development mainly regarding measurement of the magnetic field with high-resolution and high-sampling rate electric exploration devices with accurately controlled active source signals. Developed tools will be mounted underwater platforms such as deep-tow system, ROV (remotely operated vehicle), and AUV (autonomous undersea vehicle). We carried out the research cruise (vessel: JAMSTEC R/V YOKOSUKA YK09-09, cruise period: 19-29 July 2009, area surveyed: Kumano-nada, off Kii Peninsula, Japan) to investigate the performance of developed equipments for magnetic exploration. We mounted an Overhauser and two flux-gate magnetometers on the deep-tow and the AUV URASHIMA. To inspect the efficiency of equipments, it is better to measure the magnetic anomaly which is caused by known magnetic source. Therefore, we made a magnetic target which is consisted of 50 neodymium magnets. Before the navigation, the magnetic target was put under water and its position was measured by the acoustic method. The depth of target is about 2,050 meters, and the measurement was performed in the circle of a radius of about 300 meters. The vehicles were navigated at heights of 25 meters for AUV, and about 15 meters for deep-tow. Each of underwater navigation was practiced for two times. Both performances were carried out successfully, which means that we detected the significant magnetic anomalies caused by the target. We will be able to estimate three-dimensional distribution of anomalous magnetic field, and the source property of magnetic target. However, we have to resolve a lot of problems; (1) elimination of noises caused by the vehicles themselves, and their attitude, and (2) precise estimation of the position of vehicles. We will introduce the results of the research cruise and data processing in the presentation. Acknowledgement: We are grateful to captain Mr. E. Ukekura, chief officer Mr. S. Kusaka, chief AUV/DT operator Mr. T. Sakurai, and operation team, who made our difficult trials in the navigation possible by their professional skill. We also thank to the YOKOSUKA marine crew for overall support, and the engineers who take part in the development of equipments. This study is financially supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan.

75 FR 20856 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-21

... the Coast Guard on matters relating to shallow-draft inland and coastal waterway navigation and towing... advises the Secretary of Homeland Security on matters relating to shallow-draft inland and coastal... with shallow-draft inland and coastal waterway navigation and towing safety. Registered lobbyists are...

Evaluating the use of tow plows in Michigan.

DOT National Transportation Integrated Search

2016-09-30

The main objective of this project is to identify the cost-benefit of Tow Plow usage on different : routes in order to determine where Tow Plows can be included in the snow maintenance fleet in a : safe and economical manner. : During this study, sta...

Evaluating the use of tow plows in Michigan.

DOT National Transportation Integrated Search

2016-09-30

The main objective of this project is to identify the cost-benefit of Tow Plow usage on different routes in order to determine where Tow Plows can be included in the snow maintenance fleet in a safe and economical manner. During this study, state-of-...

78 FR 60890 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... representing the barge and towing industry reflecting a regional geographical balance; [cir] One member... general public. The Coast Guard is currently considering applications for six positions that will become... regional geographic balance; One member representing holders of active licensed Masters or Pilots of towing...

15. VIEW NORTHNORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW NORTH-NORTHEAST OF TOW TANK No. 2, DEWATERED. ENCLOSED AREAS AT BACK OF TUNNEL IS A HOUSING FOR CONDUCTING PERFORMANCE TESTING ON AIRCRAFT MODELS IN A VORTEX. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

Electron-Tunneling Magnetometer

NASA Technical Reports Server (NTRS)

Kaiser, William J.; Kenny, Thomas W.; Waltman, Steven B.

1993-01-01

Electron-tunneling magnetometer is conceptual solid-state device operating at room temperature, yet offers sensitivity comparable to state-of-art magnetometers such as flux gates, search coils, and optically pumped magnetometers, with greatly reduced volume, power consumption, electronics requirements, and manufacturing cost. Micromachined from silicon wafer, and uses tunneling displacement transducer to detect magnetic forces on cantilever-supported current loop.

Eclipse program F-106 aircraft in flight, front view

NASA Technical Reports Server (NTRS)

1997-01-01

Shot of the QF-106 aircraft in flight with the landing gear deployed. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Choice of Magnetometers and Gradiometers after Signal Space Separation.

PubMed

Garcés, Pilar; López-Sanz, David; Maestú, Fernando; Pereda, Ernesto

2017-12-16

Modern Elekta Neuromag MEG devices include 102 sensor triplets containing one magnetometer and two planar gradiometers. The first processing step is often a signal space separation (SSS), which provides a powerful noise reduction. A question commonly raised by researchers and reviewers relates to which data should be employed in analyses: (1) magnetometers only, (2) gradiometers only, (3) magnetometers and gradiometers together. The MEG community is currently divided with regard to the proper answer. First, we provide theoretical evidence that both gradiometers and magnetometers result from the backprojection of the same SSS components. Then, we compare resting state and task-related sensor and source estimations from magnetometers and gradiometers in real MEG recordings before and after SSS. SSS introduced a strong increase in the similarity between source time series derived from magnetometers and gradiometers (r² = 0.3-0.8 before SSS and r² > 0.80 after SSS). After SSS, resting state power spectrum and functional connectivity, as well as visual evoked responses, derived from both magnetometers and gradiometers were highly similar (Intraclass Correlation Coefficient > 0.8, r² > 0.8). After SSS, magnetometer and gradiometer data are estimated from a single set of SSS components (usually ≤ 80). Equivalent results can be obtained with both sensor types in typical MEG experiments.

76 FR 3647 - Towing Safety Advisory Committee; Vacancies

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... the Coast Guard on matters relating to shallow-draft inland and coastal waterway navigation and towing... Committee advises the Secretary of Homeland Security on matters relating to shallow-draft inland and coastal... operations associated with shallow-draft inland and coastal waterway navigation and towing safety. Registered...

Magnetoencephalography with a Cs-based high-sensitivity compact atomic magnetometer

NASA Astrophysics Data System (ADS)

Sheng, Jingwei; Wan, Shuangai; Sun, Yifan; Dou, Rongshe; Guo, Yuhao; Wei, Kequan; He, Kaiyan; Qin, Jie; Gao, Jia-Hong

2017-09-01

In recent years, substantial progress has been made in developing a new generation of magnetoencephalography (MEG) with a spin-exchange relaxation free (SERF)-based atomic magnetometer (AM). An AM employs alkali atoms to detect weak magnetic fields. A compact AM array with high sensitivity is crucial to the design; however, most proposed compact AMs are potassium (K)- or rubidium (Rb)-based with single beam configurations. In the present study, a pump-probe two beam configuration with a Cesium (Cs)-based AM (Cs-AM) is introduced to detect human neuronal magnetic fields. The length of the vapor cell is 4 mm, which can fully satisfy the need of designing a compact sensor array. Compared with state-of-the-art compact AMs, our new Cs-AM has two advantages. First, it can be operated in a SERF regime, requiring much lower heating temperature, which benefits the sensor with a closer distance to scalp due to ease of thermal insulation and less electric heating noise interference. Second, the two-beam configuration in the design can achieve higher sensitivity. It is free of magnetic modulation, which is necessary in one-beam AMs; however, such modulation may cause other interference in multi-channel circumstances. In the frequency band between 10 Hz and 30 Hz, the noise level of the proposed Cs-AM is approximately 10 f T/Hz1/2, which is comparable with state-of-the-art K- or Rb-based compact AMs. The performance of the Cs-AM was verified by measuring human auditory evoked fields (AEFs) in reference to commercial superconducting quantum interference device (SQUID) channels. By using a Cs-AM, we observed a clear peak in AEFs around 100 ms (M100) with a much larger amplitude compared with that of a SQUID, and the temporal profiles of the two devices were in good agreement. The results indicate the possibility of using the compact Cs-AM for MEG recordings, and the current Cs-AM has the potential to be designed for multi-sensor arrays and gradiometers for future neuroscience studies.

Data Collection and Analysis for Personnel Detection at a Border Crossing

DTIC Science & Technology

2011-01-01

3 Figure 4. Picture of fluxgate magnetometer ...materials carried by people, e.g., keys, firearms, and knives. For the experiment we used Model 1540 three-axis fluxgate magnetometers from Applied... magnetometer were collected at 10 samples per second. Figure 4 shows a photo of the emplaced fluxgate magnetometer . 4 Figure 4. Picture of fluxgate

Method of performing MRI with an atomic magnetometer

DOEpatents

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2012-11-06

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

Method of performing MRI with an atomic magnetometer

DOEpatents

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2013-08-27

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

Response of a Bell–Bloom Magnetometer to a Magnetic Field of Arbitrary Direction

PubMed Central

Ding, Zhichao; Yuan, Jie; Long, Xingwu

2018-01-01

The Bell–Bloom magnetometer in response to a magnetic field of arbitrary direction is observed theoretically and experimentally. A theoretical model is built from a macroscopic view to simulate the magnetometer frequency response to an external magnetic field of arbitrary direction. Based on the simulation results, the magnetometer characteristics, including the signal phase and amplitude at resonance, the linewidth, and the magnetometer sensitivity, are analyzed, and the dependencies of these characteristics on the external magnetic field direction are obtained, which are verified by the experiment. PMID:29724059

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Definitions. 27.101 Section 27.101 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... means a towing vessel that is not in ocean or coastal service. Towing vessel in ocean or coastal service...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Definitions. 27.101 Section 27.101 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... means a towing vessel that is not in ocean or coastal service. Towing vessel in ocean or coastal service...

Use of water towing tanks for aerodynamics and hydrodynamics

NASA Technical Reports Server (NTRS)

Gadelhak, Mohamed

1987-01-01

Wind tunnels and flumes have become standard laboratory tools for modeling a variety of aerodynamic and hydrodynamic flow problems. Less available, although by no means less useful, are facilities in which a model can be towed (or propelled) through air or water. This article emphasizes the use of the water towing tank as an experimental tool for aerodynamic and hydrodynamic studies. Its advantages and disadvantages over other flow rigs are discussed, and its usefullness is illustrated through many examples of research results obtained over the past few years in a typical towing tank facility.

Torsionally rigid support apparatus for marine seismic transducer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, W.J.; Cole, J.H.

1989-11-14

This patent describes apparatus for supporting a marine seismic transducer from a vessel. It comprises: an elongated substantially rigid towing arm; a connector means for connecting the transducer to a lower end of the towing arm; a swivel member which is secured to the vessel and is pivotable about a generally horizontal first axis transverse to a length of the vessel; and a support means for pivotally connecting an upper end of the towing arm to the swivel member. The support means being pivotal relative to the swivel member about a second axis transverse to a longitudinal axis of themore » towing arm. The support means being substantially rigid so as to prevent any substantial rotation of the towing arm about its the longitudinal axis.« less

Effects of Fiber Coatings on Tensile Properties of Hi-Nicalon SiC/RBSN Tow Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.; Hull, David R.

1997-01-01

Uncoated Hi-Nicalon silicon carbide (SiC) fiber tows and those coated with a single surface layer of pyrolytic boron nitride (PBN), double layers of PBN/Si-rich PBN, and boron nitride (BN)/SiC coatings deposited by chemical vapor deposition (CVD) method were infiltrated with silicon slurry and then exposed to N2, for 4 hr at 1200 and 1400 C. Room temperature ultimate tensile fracture loads and microstructural characterization of uncoated and CVD coated Hi-Nicalon SiC fiber reinforced reaction-bonded silicon nitride (RBSN) tow composites were measured to select suitable interface coating(s) stable under RBSN processing conditions. Results indicate that room temperature ultimate fracture loads of the uncoated Hi-Nicalon SiC/RBSN tow composites nitrided at both temperatures were significantly lower than those of the uncoated Hi-Nicalon tows without slurry infiltration. In contrast, all CVD coated Hi-Nicalon SiC/RBSN tow composites retained a greater fraction of the dry tow fracture load after nitridation at 1200 C, but degraded significantly after nitridation at 1400 C. Reaction between metal impurities (Fe and Ni) present in the attrition milled silicon powder and uncoated regions of SiC fibers appears to be the probable cause for fiber degradation.

Stress-Dependent Matrix Cracking in 2D Woven SiC-Fiber Reinforced Melt-Infiltrated SiC Matrix Composites

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.

2003-01-01

The matrix cracking of a variety of SiC/SiC composites has been characterized for a wide range of constituent variation. These composites were fabricated by the 2-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with SiC particles followed by molten infiltration of Si. The composites varied in number of plies, the number of tows per length, thickness, and the size of the tows. This resulted in composites with a fiber volume fraction in the loading direction that ranged from 0.12 to 0.20. Matrix cracking was monitored with modal acoustic emission in order to estimate the stress-dependent distribution of matrix cracks. It was found that the general matrix crack properties of this system could be fairly well characterized by assuming that no matrix cracks originated in the load-bearing fiber, interphase, chemical vapor infiltrated Sic tow-minicomposites, i.e., all matrix cracks originate in the 90 degree tow-minicomposites or the large unreinforced Sic-Si matrix regions. Also, it was determined that the larger tow size composites had a much narrower stress range for matrix cracking compared to the standard tow size composites.

Design and Manufacturing of Tow-Steered Composite Shells Using Fiber Placement

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Tatting, Brian F.; Smith, Brett H.; Stevens, Randy S.; Occhipiniti, Gina P.; Swift, Jonathan B.; Achary, David C.; Thornburgh, Robert P.

2009-01-01

Advanced composite shells that may offer the potential to improve the structural performance of future aircraft fuselage structures were developed under this joint NASA-industry collaborative effort. Two cylindrical shells with tailored, tow-steered layups and continuously varying fiber angle orientations were designed and built at the National Center for Advanced Manufacturing - Louisiana Partnership. The shells were fabricated from unidirectional IM7/8552 graphite-epoxy pre-preg slit tape material fiber-placed on a constant-diameter mandrel. Each shell had the same nominal 8-ply [plus or minus 45/plus or minus Theta]s layup, where the nominal fiber angle in the tow-steered plies varied continuously from 10 degrees along the crown to 45 degrees on each side, then back to 10 degrees on the keel. One shell was fabricated with all 24 tows placed during each pass of the fiber placement machine, resulting in many tow overlaps on the shell surface. The fiber placement machine's individual tow cut/restart capability was also used to manufacture a second shell with tow drops and a more uniform laminate thickness. This paper presents an overview of the detailed design and manufacturing processes for these shells, and discusses issues encountered during their fabrication and post-cure evaluation. Future plans for structural testing and analyses of the shells are also discussed.

The polarization and the fundamental sensitivity of 39K (133Cs)-85Rb-4He hybrid optical pumping spin exchange relaxation free atomic magnetometers.

PubMed

Liu, Jian-Hua; Jing, Dong-Yang; Wang, Liang-Liang; Li, Yang; Quan, Wei; Fang, Jian-Cheng; Liu, Wu-Ming

2017-07-28

The hybrid optical pumping spin exchange relaxation free (SERF) atomic magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85 Rb polarization of two types of hybrid optical pumping SERF magnetometers based on 39 K- 85 Rb- 4 He and 133 Cs- 85 Rb- 4 He respectively. Then we found that 85 Rb polarization varies with the number density of buffer gas 4 He and quench gas N 2 , pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10 -18 T) with 39 K- 85 Rb- 4 He magnetometer between above two types of magnetometers when 85 Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10 -2 aT/Hz 1/2 , which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.

Eclipse program QF-106 aircraft in flight

NASA Technical Reports Server (NTRS)

1997-01-01

This photo shows one of the QF-106s used in the Eclipse project in flight. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Lunar surface magnetometers

NASA Technical Reports Server (NTRS)

Dyal, P.; Gordon, D. I.

1973-01-01

Discussion of the properties of both the stationary and portable magnetometers used in the Apollo program to measure static and dynamic fields on the lunar surface. A stationary magnetometer is described in which the three orthogonal vector components of the magnetic field are measured by three fluxgate sensors which are located at the ends of three orthogonal booms and contain ferromagnetic cores driven to saturation by means of a periodic current. In the Apollo 16 magnetometer special high-stability ring-core sensors were used which provided an output voltage to the analog-to-digital converter which is proportional to the magnetic field. A portable magnetometer is described which consists of a set of three orthogonal fluxgate sensors mounted on top of a tripod connected to an electronics box by a ribbon cable. The above-mentioned stationary magnetometer simultaneously measured the time-varying components of the field which were later subtracted from the portable magnetometer measurements to give the desired resultant steady field values caused by the magnetized crustal material.

Revisiting the Cretaceous Normal Superchron in the SW Indian Ocean

NASA Astrophysics Data System (ADS)

Dyment, J.; Gallet, Y.; Granot, R.; Seama, N.; Poitou, C.; Okino, K.; Sato, T.; Choe, H.; Pasenko, A.; Phua, M.; Roth, S.; Zhang, T.; Hemond, C.; Blanc, M.; Kraus, E.; Makuzeni, M.; Raifman, G.; Razafimamonjy, V. S.; Schatz, A.; Resseguier, F.

2017-12-01

The Cretaceous Normal Superchron (CNS) is a 40 Myr-long period of constant normal geomagnetic polarity during which no geomagnetic reversal has been convincingly observed so far. It extended from Chron M0 ( 120 Ma) to Chron 34 (83 Ma). In a previous study we showed that significant differences in the variability of the geomagnetic dipole moment exist within the CNS, with long wavelength, low amplitude variations in its first third, short wavelength, high amplitude variations within the median third, and long wavelength, very low amplitude variations in the last third (Granot et al., Nature Geoscience, 2012). We also demonstrated the existence of markers that can be identified within the CNS and allow intermediate plate reconstructions between Chrons M0 and 34 (Granot & Dyment, EPSL, 2015). Our inspection of a global set of marine magnetic profiles suggested that the Mozambique Basin and its conjugate off Antarctica may host the best records of the CNS We therefore carried out project Magofond 4, a two leg-expedition (January-March 2017) in this area to better constrain (1) the variability in magnetic dipole moment, the possible occurrence of short reversed polarity intervals, and more generally the evolution of the geodynamo during, immediately before and after the CNS, and (2) the presence of markers allowing detailed reconstructions of the Antarctic and African plates within the CNS. During Leg 1 onboard R/V Pourquoi pas?, we acquired a long deep tow, high-resolution magnetic profile across the median part of the CNS, a shorter profile across Chron 33r, and three sea-surface magnetic profiles across the CNS in the Mozambique Basin. During Leg 2 onboard R/V Marion Dufresne, we acquired four sea-surface magnetic profiles across the CNS in the Riiser-Larsen Sea. A sea-surface vector magnetometer and two scalar magnetometers (gradiometer) were used during half of Leg 2. During both legs we collected (almost) continuously shipboard three-component magnetics, multibeam bathymetry and imagery, sub-bottom profiler data, and gravity. Best use was made of the transits to acquire valuable data across the SWIR. We will present the cruise, the data, and some initial results.

33 CFR 83.35 - Sound signals in restricted visibility (Rule 35).

Code of Federal Regulations, 2010 CFR

2010-07-01

... engaged in fishing; vessels engaged in towing or pushing. A vessel not under command; a vessel restricted... fishing, whether underway or at anchor; and a vessel engaged in towing or pushing another vessel shall... made by the towing vessel. (e) Pushing and pushed vessels connected in composite unit. When a pushing...

Tow Tank Dynamic Test Rig Drawings and Bill of Materials for the Aquantis 2.5 MW Ocean Current Generation Device

DOE Data Explorer

Swales, Henry; Banko, Richard; Coakley, David

2015-06-03

Aquantis 2.5 MW Ocean Current Generation Device, Tow Tank Dynamic Test Rig Drawings and Bill of Materials. This submission contains information on the equipment for the scaled model tow tank testing. The information includes hardware, test protocols, and plans.

46 CFR 11.463 - General requirements for national endorsements as master, mate (pilot), and apprentice mate...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false General requirements for national endorsements as master... national endorsements as master, mate (pilot), and apprentice mate (steersman) of towing vessels. (a) The Coast Guard issues the following endorsements for towing vessels: (1) Master of towing vessels. (2...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

78 FR 14314 - Towing Safety Advisory Committee; Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... Regarding Manning of Inspected Towing Vessels. On March 21, 2013 from 8 a.m. to 5:30 p.m. and on March 22... Vessels. An interim report will be given. (7) Recommendations regarding Manning of Inspected Towing...) Recommendations for the Standardization of Tug/Towboat Definitions, and; (3) Recommendations for Wake and Surge...

The Status of Infantry TOW, LAW, and Dragon Training in USAREUR.

DTIC Science & Technology

1977-11-01

TOW duties (guard, CQ runner , etc.); (b) Permanent assignment to other than TOW duties; (c) medical and dental appointments and drug and alcohol abuse...in training areas would be most helpful, and a third said American tanks and ve- hicles could be mocked-up to look like enemy targets and that kites

Electrically-Conductive Polyaramid Cable And Fabric

NASA Technical Reports Server (NTRS)

Orban, Ralph F.

1988-01-01

Tows coated with metal provide strength and conductance. Cable suitable for use underwater made of electrically conductive tows of metal-coated polyaramid filaments surrounded by electrically insulating jacket. Conductive tows used to make conductive fabrics. Tension borne by metal-coated filaments, so upon release, entire cable springs back to nearly original length without damage.

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

46 CFR 15.610 - Master and mate (pilot) of towing vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Master and mate (pilot) of towing vessels. 15.610 Section 15.610 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Uninspected Vessels § 15.610 Master and mate (pilot) of towing...

49 CFR 393.43 - Breakaway and emergency braking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

49 CFR 393.43 - Breakaway and emergency braking.

Code of Federal Regulations, 2011 CFR

2011-10-01

... protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

Fabrication of Superconducting Quantum Interference Device Magnetometers on a Glass Epoxy Polyimide Resin Substrate with Copper Terminals

NASA Astrophysics Data System (ADS)

Kawai, Jun; Kawabata, Miki; Oyama, Daisuke; Uehara, Gen

We have developed fabrication technique of superconducting quantum interference device (SQUID) magnetometers based on Nb/AlAlOx/Nb junctions directly on a glass epoxy polyimide resin substrate, which has copper terminals embedded in advance. The advantage of this method is that no additional substrate and wirebonds are needed for assembly. Compared to conventional SQUID magnetometers, which are assembled with a SQUID chip fabricated on a Si substrate and wirebonding technique, low risk of disconnection can be expected. A directly-coupled multi-loop SQUID magnetometer fabricated with this method has as good noise performance as a SQUID magnetometer with the same design fabricated on a Si wafer. The magnetometer sustained its performance through thermal cycle test 13 times so far.

Magnetocardiogram measured by fundamental mode orthogonal fluxgate array

NASA Astrophysics Data System (ADS)

Karo, Hikaru; Sasada, Ichiro

2015-05-01

Magnetocardiography (MCG) of healthy volunteers has been measured by using a fundamental mode orthogonal fluxgate magnetometer array of 32 channels in a magnetic shielded room (MSR). Sensor heads, which are employed, consist of a 45 mm long U-shaped amorphous wire core and a 1000-turn solenoid pick-up coil of 30 mm in length and 3 mm in outer diameter. The excitation current of 100 kHz with large dc bias current is fed directly into wire cores, which are connected in series, whereas the signal detection circuit is provided to each of the sensor heads. A special technique to avoid mutual interaction between sensor heads is implemented, where all the sensor heads are excited synchronously by using a single ac source. A 2-D array having 32 sensors with 4 cm grid spacing was used to measure MCG signals inside an MSR. Measured data from each channel were first filtered (0.16-100 Hz pass band), then averaged for 2 min synchronously with electrocardiogram's peaks taken from both hands. Noise remaining after the average is about 1.8 pTrms for the band-width of 0.16-100 Hz. The QRS complex and the T-wave are clearly detected.

The MASCOT Magnetometer

NASA Astrophysics Data System (ADS)

Herčík, David; Auster, Hans-Ulrich; Blum, Jürgen; Fornaçon, Karl-Heinz; Fujimoto, Masaki; Gebauer, Kathrin; Güttler, Carsten; Hillenmaier, Olaf; Hördt, Andreas; Liebert, Evelyn; Matsuoka, Ayako; Nomura, Reiko; Richter, Ingo; Stoll, Bernd; Weiss, Benjamin P.; Glassmeier, Karl-Heinz

2017-07-01

The Mobile Asteroid Scout (MASCOT) is a small lander on board the Hayabusa2 mission of the Japan Aerospace Exploration Agency to the asteroid 162173 Ryugu. Among the instruments on MASCOT is a fluxgate magnetometer, the MASCOT Magnetometer (MasMag). The magnetometer is a lightweight (˜280 g) and low power (˜0.5 W) triaxial fluxgate magnetometer. Magnetic field measurements during the landing period and during the surface operational phase shall provide information about any intrinsic magnetic field of the asteroid and its remanent magnetization. This could provide important constraints on planet formation and the thermal and aqueous evolution of primitive asteroids.

Autonomous navigation system based on GPS and magnetometer data

NASA Technical Reports Server (NTRS)

Julie, Thienel K. (Inventor); Richard, Harman R. (Inventor); Bar-Itzhack, Itzhack Y. (Inventor)

2004-01-01

This invention is drawn to an autonomous navigation system using Global Positioning System (GPS) and magnetometers for low Earth orbit satellites. As a magnetometer is reliable and always provides information on spacecraft attitude, rate, and orbit, the magnetometer-GPS configuration solves GPS initialization problem, decreasing the convergence time for navigation estimate and improving the overall accuracy. Eventually the magnetometer-GPS configuration enables the system to avoid costly and inherently less reliable gyro for rate estimation. Being autonomous, this invention would provide for black-box spacecraft navigation, producing attitude, orbit, and rate estimates without any ground input with high accuracy and reliability.

Weavability of dry polymer powder towpreg

NASA Technical Reports Server (NTRS)

Hugh, Maylene K.; Marchello, Joseph M.; Maiden, Janice R.; Johnston, Norman J.

1993-01-01

Carbon fiber yarns (3k, 6k, 12k) were impregnated with LARC (tm) thermoplastic polyimide dry powder. Parameters for weaving these yarns were established. Eight-harness satin fabrics were successfully woven from each of the three classes of yarns and consolidated into test specimens to determine mechanical properties. It was observed that for optimum results warp yarns should have flexural rigidities between 10,000 and 100,000 mg-cm. Tow handling minimization, low tensioning, and tow bundle twisting were used to reduce fiber breakage, the separation of filaments, and tow-to-tow abrasion. No apparent effect of tow size or twist was observed on either tension or compression modulus. However, fiber damage and processing costs favor the use of 12k yarn bundles versus 3k or 6k yarn bundles in the weaving of powder-coated towpreg.

Eclipse project QF-106 and C-141A takeoff on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW ROPE TAKEOFF - The Kelly Space & Technology (KST)/USAF Eclipse project's modified QF-106 and a USAF C-141A takeoff for the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Development of a Micro-Fabricated Total-Field Magnetometer

DTIC Science & Technology

2011-03-01

are made with fluxgate technologies. Fluxgates have lower sensitivity than Cs magnetometers , yet they continue to be used in small wands simply...extraction process by providing the sensitivity of a Cs magnetometer with the convenience and low cost of a fluxgate wand. Extremely small and low cost...FINAL REPORT Development of a Micro-Fabricated Total-Field Magnetometer SERDP Project MR-1512 MARCH 2011 Mark Prouty Geometrics, Inc

The DMSP Space Weather Sensors Data Archive Listing (1982-2013) and File Formats Descriptions

DTIC Science & Technology

2014-08-01

environment sensors including the auroral particle spectrometer (SSJ), the fluxgate magnetometer (SSM), the topside thermal plasma monitor (SSIES... Fluxgate Magnetometer (SSM) for the Defense Meteorological Satellite Program (DMSP) Block 5D-2, Flight 7, Instrument Papers, AFGL-TR-84-0225; ADA155229...Flux) SSM The fluxgate magnetometer . (Special Sensor, Magnetometer ) SSULI The ultraviolet limb imager SSUSI The ultraviolet spectrographic imager

Demonstration of an Enhanced Vertical Magnetic Gradient System for UXO

DTIC Science & Technology

2008-04-01

flights were conducted and results evaluated. The cesium magnetometers , GPS systems (positioning and attitude), fluxgate magnetometers , data...makes a measurement and when it is time-stamped and recorded. This applies to the magnetometers , fluxgate and the GPS. Accurate positioning...requires a correction for this lag. Time lags between the magnetometers , fluxgate and GPS signals were measured by a proprietary utility. This utility

Man-Portable Simultaneous Magnetometer and EM System (MSEMS)

DTIC Science & Technology

2008-12-01

expensive fluxgate magnetometers . This is because the interleaving hardware is expecting a Larmor signal as input; it performs period counting of the...Larmor signal between EM61 pulses to convert the frequency-based Larmor signal into nanotesla. A fluxgate magnetometer does not employ the resonance...FINAL REPORT Man-Portable Simultaneous Magnetometer and EM System (MSEMS) ESTCP Project MM-0414 December 2008 Robert Siegel Science

Vector Fluxgate Magnetometer (VMAG) Development for DSX

DTIC Science & Technology

2008-05-19

AFRL-RV-HA-TR-2008-1108 Vector Fluxgate Magnetometer (VMAG) Development for DSX Mark B. Moldwin Q. O O O I- UCLA Q Institute of...for Public Release; Distribution Unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT UCLA is building a three-axis fluxgate magnetometer for the Air... fluxgate magnetometer provides the necessary data to support both the Space Weather (SWx) specification and mapping requirements and the WPIx

Feasibility Study for an Autonomous UAV - Magnetometer System

DTIC Science & Technology

2007-11-01

collect data from multiple magnetometers at high sampling rates (~100 Hz), and associated with these acquisition systems are highly accurate...component for an UAV helicopter- magnetometer system is the ability to have precise positioning (both for flightpath execution and for data acquisition...discussed under section 6.3. Figure 6.11 shows the fluxgate data used to compensate a total field magnetometer as previously described. The red

Artificial Earth Satellites Designed and Fabricated by The Johns Hopkins University Applied Physics Laboratory. Revised

DTIC Science & Technology

1978-07-01

occurred. The attitude detection system included a three-axis fluxgate vector magnetometer and solar attitude detectors that produced both analog and digital ...heliogoniometer ( digital solar attitudeIsensing system) Three axis analog solar detection - Rubidium vapor magnetometer Three axis fluxgate magnetometer ...Telemetry: 35 channels modulating 150 MHz carrier on command Three axis solar attitude detector system Three axis fluxgate magnetometer system

Investigation of Magnetic Field Measurements.

DTIC Science & Technology

1983-02-28

Report) Ill. SUPPLEMENTARY NOTES IS. KEY WORDS (CoEntnue on revere side I necoseer mnd Identify by block mamber) AFGL Magnetometer Network Fluxgate ... Magnetometer Induction Coil Magnetometer Temperature Dependency of Fluxgate Automation of Testing 20. ABSTRACT (Coniniue an reverse aide If neeeeey and...data collection platforms. Support was also provided to AFGL to process the fluxgate magnetometer archive tapes in order to make the data available to

KSC-2011-2488

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2487

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2486

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2491

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2484

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2485

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2492

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., check out solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2489

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2490

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2479

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

33 CFR 83.24 - Towing and pushing (Rule 24).

Code of Federal Regulations, 2012 CFR

2012-07-01

... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

33 CFR 83.24 - Towing and pushing (Rule 24).

Code of Federal Regulations, 2013 CFR

2013-07-01

... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

System and Method for Air Launch from a Towed Aircraft

NASA Technical Reports Server (NTRS)

Budd, Gerald D (Inventor)

2018-01-01

The invention is a system and method of air launching a powered launch vehicle into space or high altitude. More specifically, the invention is a tow aircraft which tows an unpowered glider, with the powered launch vehicle attached thereto, to launch altitude. The powered launch vehicle is released from the unpowered glider and powered on for launch.

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

46 CFR 11.464 - Requirements for national endorsements as master of towing vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for national endorsements as master of... Deck Officer Endorsements § 11.464 Requirements for national endorsements as master of towing vessels. (a) An applicant for an endorsement as master of towing vessels with a route listed in column 1 of...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... may be used for connections between towed and towing motor vehicles or between the frame of a towed...

Does a tow-bar increase the risk of neck injury in rear-end collisions?

PubMed

Olesen, Anne Vingaard; Elvik, Rune; Andersen, Camilla Sloth; Lahrmann, Harry S

2018-06-01

Does a tow-bar increase the risk of neck injury in the struck car in a rear-end collision? The rear part of a modern car has collision zones that are rendered nonoperational when the car is equipped with a tow-bar. Past crash tests have shown that a car's acceleration was higher in a car equipped with a tow-bar and also that a dummy placed in a car with a tow-bar had higher peak acceleration in the lower neck area. This study aimed to investigate the association between the risk of neck injury in drivers and passengers, and the presence of a registered tow-bar on the struck car in a rear-end collision. We performed a merger of police reports, the National Hospital Discharge Registry, and the National Registry of Motor Vehicles in Denmark. We identified 9,370 drivers and passengers of whom 1,519 were diagnosed with neck injury within the first year after the collision. We found a statistically insignificant 5% decrease in the risk of neck injury in the occupants of the struck car when a tow-bar was fitted compared to when it was not fitted (hazard ratio=0.95; 95% confidence level=0.85-1.05; p=0.32). The result was controlled for gender, age, and the seat of the occupant. Several other collision and car characteristics and demographic information on the drivers and passengers were evaluated as confounders but were not statistically significant. The present study may serve as valuable input for a meta-analysis on the effect of a tow-bar because negative results are necessary in order to avoid publication bias. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vector Fluxgate Magnetometer (VMAG) Development for DSX

DTIC Science & Technology

2010-06-03

AFRL-RV-HA-TR-2010-1056 Vector Fluxgate Magnetometer (VMAG) Development for DSX Mark B. Moldwin UCLA Institute of Geophysics... Fluxgate Magnetometer (VMAG) Development for DSX 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62601F 6. AUTHOR(S) Mark B. Moldwin 5d. PROJECT...axis fluxgate magnetometer for the AFRL-mission. The instrument is designed to measure the medium-Earth orbit geomagnetic field with precision of 0.1

Underwater (UW) Unexploded Ordnance (UXO) Multi-Sensor Data Base (MSDB) Collection

DTIC Science & Technology

2009-07-01

11 FIGURE 6 RTG SENSOR. FOUR SENSOR TRIADS ARE SHOWN, EACH WITH A 3-AXIS FLUXGATE MAGNETOMETER ...used by RTG to measure the gradients. Each triad includes a 3-axis fluxgate magnetometer and a set of feedback coils. The outputs of three triad...each with a 3-axis fluxgate magnetometer (internal, not clearly visible) and a set of 3 feedback coils. The upper triad 3-axis magnetometer

Evaluation of a Three-Channel High-Temperature Superconducting Magnetometer System

DTIC Science & Technology

1997-06-01

achieved by the best commercially available fluxgate magnetometers demonstrated to date and is only surpassed by low temperature superconducting...wire lines carry the analog SQUID magnetometer signal as well as dc power and ground, and the fiberoptic lines carry digital clock and data signals...with the magnetometers mounted on the three-sensor probe used in the sensor evaluated here. This probe is not highly stabilized with respect to the

Vector Fluxgate Magnetometer (VMAG) Development for DSX

DTIC Science & Technology

2007-07-02

AFRL-RV-HA-TR-2007-1077 Vector Fluxgate Magnetometer (VMAG) Development for DSX -- Mark B. Moldwin 0 UCLA Institute of Geophysics and Planetary...02-07-2007IScientific Report No. 2 April 2006 - April 2007 4. TITLE AND SUBTITLE S. CONTRACT NUMBER Vector Fluxgate Magnetometer (VMAG) Development...SUPPLEMENTARY NOTES 14. ABSTRACT UCLA is building a three-axis fluxgate magnetometer for the AFRL-mission. The instrument is designed to measure the medium

Wind-Tunnel Investigation of a Balloon as a Towed Decelerator at Mach Numbers from 1.47 to 2.50

NASA Technical Reports Server (NTRS)

McShera, John T.; Keyes, J. Wayne

1961-01-01

A wind-tunnel investigation has been conducted to study the characteristics of a towed spherical balloon as a drag device at Mach numbers from 1.47 to 2.50, Reynolds numbers from 0.36 x 10(exp 6) to 1.0 x 10(exp 6) , and angles of attack from -15 to 15 deg. Towed spherical balloons were found to be stable at supersonic speeds. The drag coefficient of the balloon is reduced by the presence of a tow cable and a further reduction occurs with the addition of a payload. The balloon inflation pressure required to maintain an almost spherical shape is about equal to the free-stream dynamic pressure. Measured pressure and temperature distribution around the balloon alone were in fair agreement with predicted values. There was a pronounced decrease in the pressure coefficients on the balloon when attached to a tow cable behind a payload.

Wind Tunnel Investigation of a Balloon as Decelerator at Mach Numbers from 1.47 to 2.50

NASA Technical Reports Server (NTRS)

McShera, John T.; Keyes, J. Wayne

1961-01-01

A wind-tunnel investigation was conducted to study the characteristics of a towed spherical balloon as a drag device at Mach numbers from 1.47 to 2.50, Reynolds numbers from 0.36 x 10(exp 6) to 1.0 x 10(exp 6) , and angles of attack from -15 to 15 degrees. Tow-cable length was approximately 24 inches from asymmetric body to cone on the upstream side of the balloon. As the tow cable was lengthened the balloon reached a point in the test section where wall-reflected shocks intersected the balloon and caused severe oscillations. As a result, the tow cable broke and the inflatable balloon model was destroyed. Further tests used a model rigid plastic sphere 6.75 inches in diameter. Tow cable length was approximately 24 inches from asymmetric body to the upstream side of the sphere.

The Pioneer XI high field fluxgate magnetometer

NASA Technical Reports Server (NTRS)

Acuna, M. A.; Ness, N. F.

1975-01-01

The high field fluxgate magnetometer experiment flown aboard the Pioneer XI spacecraft is described. This extremely simple instrument was used to extend the spacecraft's upper-limit measurement capability by approximately an order of magnitude (from 0.14 mT to 1.00 mT) with minimum power and volume requirements. This magnetometer was designed to complement the low-field measurements provided by a helium vector magnetometer and utilizes magnetic ring core sensors with biaxial orthogonal sense coils. The instrument is a single-range, triaxial-fluxgate magnetometer capable of measuring fields of up to 1 mT along each orthogonal axis, with a maximum resolution of 1 microT.

A Reduced SWAP+C DC Magnetometer for Geomagnetic and Space Physics Research

NASA Astrophysics Data System (ADS)

Moldwin, M.; Ojeda, L.; Rogacki, S.; Pelloni, M.; Regoli, L.

2016-12-01

A new small, low mass, low power consumption, and low cost (reduced SWaP+C or Size, Weight and Power + Cost) magnetometer is being developed for both ground-based and future CubeSat Constellation-class missions. The University of Michigan (UM) magnetometer is based on the PNI Induction magnetometer electronics. PNI 3100 magnetometers have flight heritage on Cubesat Missions (e.g., the UM RAXs mission), but they were used primarily for attitude control. This presentation describes the modifications and performance of the magnetometer and our strategies for continued improvement in performance and its environmental testing. A description of further development of this new magnetometer with regards to its ability to measure geophysical signals up to 10 Hz is also given. Current performance has noise levels of about 1 nT/root Hz at 1 Hz, temperature stability, inherent radiation tolerance, in a 3 x 5 cm package (electronics and sensors), draws 10s of mW and costs a few hundred dollars. We will also present several strategies to reduce the noise by a factor of 5-10 that are currently being pursued.

Processing of DMSP magnetic data and its use in geomagnetic field modeling

NASA Technical Reports Server (NTRS)

Ridgway, J. R.; Sabaka, T. J.; Chinn, D.; Langel, R. A.

1989-01-01

The DMSP F-7 satellite is an operational Air Force meteorological satellite which carried a magnetometer for geophysical measurements. The magnetometer was located within the body of the spacecraft in the presence of large spacecraft fields. In addition to stray magnetic fields, the data have inherent position and time inaccuracies. Algorithms were developed to identify and remove time varying magnetic field noise from the data. Techniques developed for Magsat were then modified and used to attempt determination of the spacecraft fields, of any rotation between the magnetometer axes and the spacecraft axes, and of any scale changes within the magnetometer itself. The corrected data were then used to attempt to model the geomagnetic field. This was done in combination with data from Magsat, from the standard magnetic observatories, from aeromagnetic and other survey data, and from DE-2 spacecraft field data. Future DMSP missions can be upgraded in terms of geomagnetic measurements by upgrading the time and position information furnished with the data, placing the magnetometer at the end of the boom, upgrading the attitude determination at the magnetometer, and increasing the accuracy of the magnetometer.

Magnetization strucrure of thermal vent on island arc from vector magnetic anomlies using AUV

NASA Astrophysics Data System (ADS)

Isezaki, N.; Matsuo, J.; Sayanagi, K.

2012-04-01

The geomagnetic anomaly measured by a scalar magnetometer,such as a proton precession magnetometer cannot be defined its direction, then it does not satisfy the Laplace's equation. Therefore physical formula describing the relation between magnetic field and magnetization cannot be established.Because the difference between results obtained from scalar data and from vector data is very significant, we must use vector magnetic field data for magnetization analyses to get the more reliable and exact solutions. The development program of fundamental tools for exploration of deep seabed resources started with the financial support of the Ministry of Education, Culture, Sports, Science & Technology (MEXT) in 2008 and will end in 2012. In this project, we are developing magnetic exploration tools for seabed resources using AUV (Autonomous Underwater Vehicle) and other deep-towed vehicles to measure not the scalar magnetic field but the vector magnetic field in order to estimate magnetization structure below the sea-floor exactly and precisely. We conducted AUV magnetic survey in 2010 at the thermal area called Hakurei deposit in the Bayonnaise submarine caldera at the southern end of Izu island arc, about 400km south of Tokyo. We analyzed the observed vector magnetic fields to get the vector magnetic anomaly Fields using the method of Isezaki(1984). We inverted these vector magnetic anomaly fields to magnetization structure. CONCLUSIONS 1.The scalar magnetic field TIA (Total Intensity Anomaly) has no physical formula describing the relation between M (Magnetization) and TIA because TIA does not satisfy the Laplace's equation. Then it is impossible to estimate M from TIA. 2.Anlyses of M using TIA have been done so far under assumption TIA=PTA (Projected Total Anomay on MF (Main Geomagnetic Field)), however, which caused the analysis error due to ɛT= TIA - PTA . 3.We succeeded to measure the vector magnetic anomaly fields using AUV despite the severe magnetic noises around the magnetometer sensors. The method of Isezaki(1984) works good to eliminate these noises. 4.We got the very precise magnetization structure in the Bayonnaise submarine caldera area at the southern end of Izu island arc. We used the prism model which forms the shape of magnetized source body whose top is the sea-floor. The total number od prisms is 1500 making the 3 layers (0-80m, 80-160m, 160- 240m below the sea-floor, 25x20=500 prisms in 1 layer). The 4500 unknowns(3 unknowns, Mx,My,Mz in each prosm) are obtained from 12000 observed vector magnetic anomaly fields by inversion method. 5. The tentative result shows that the 1st and 2nd layers have smaller intensity of magnetization compared to the 3rd layer. The 2nd layer has the smallest of three layers. However the Hakurei deposit area in the 2nd layer has the a little bit greater magnetization than surrounding area which suggests that the Hakurei deposit includes some magnetic minerals. 6.We strongly recommend to carry out the magnetic survey using a three component magnetometer to get TF and TA which have many advantages for magnetic analyses (magnetization, upward continuation etc.) which cannot be done using scalar TIA.

Cross-flow turbines: progress report on physical and numerical model studies at large laboratory scale

NASA Astrophysics Data System (ADS)

Wosnik, Martin; Bachant, Peter

2016-11-01

Cross-flow turbines show potential in marine hydrokinetic (MHK) applications. A research focus is on accurately predicting device performance and wake evolution to improve turbine array layouts for maximizing overall power output, i.e., minimizing wake interference, or taking advantage of constructive wake interaction. Experiments were carried with large laboratory-scale cross-flow turbines D O (1 m) using a turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. Several turbines of varying solidity were employed, including the UNH Reference Vertical Axis Turbine (RVAT) and a 1:6 scale model of the DOE-Sandia Reference Model 2 (RM2) turbine. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier-Stokes models. Results are presented for the simulation of performance and wake dynamics of cross-flow turbines and compared with experiments and body-fitted mesh, blade-resolving CFD. Supported by NSF-CBET Grant 1150797, Sandia National Laboratories.

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

46 CFR 31.15-10 - Towing vessels may carry persons in addition to crew-B/LBR.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Towing vessels may carry persons in addition to crew-B/LBR. 31.15-10 Section 31.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-10 Towing vessels may carry persons in addition...

76 FR 36314 - Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

..., levee system, vessels and tows from destruction, loss or injury due to hazards associated with rising... the general public, levee system, vessels and tows from the hazards associated with rising flood water... system, vessels and tows from destruction, loss or injury due to the hazards associated with rising flood...

49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... may be used for connections between towed and towing motor vehicles or between the frame of a towed... in a spring guard or similar device which prevents the tubing from kinking at the fitting at which it is attached to the vehicle; and (2) The spring guard or similar device has at least 51 mm (2 inches...

M2-F1 in flight over lakebed on tow line

NASA Image and Video Library

1963-08-30

Following the first M2-F1 airtow flight on 16 August 1963, the Flight Research Center used the vehicle for both research flights and to check out new lifting-body pilots. These included Bruce Peterson, Don Mallick, Fred Haise, and Bill Dana from NASA. Air Force pilots who flew the M2-F1 included Chuck Yeager, Jerry Gentry, Joe Engle, Jim Wood, and Don Sorlie, although Wood, Haise, and Engle only flew on car tows. In the three years between the first and last flights of the M2-F1, it made about 400 car tows and 77 air tows.

International solar polar mission: The vector helium magnetometer

NASA Technical Reports Server (NTRS)

1982-01-01

The functional requirements for the vector helium magnetometer (VHM) on the Solar Polar spacecraft are presented. The VHM is one of the two magnetometers on board that will measure the vector magnetic field along the Earth to Jupiter transfer trajectory, as well as in the vicinity of Jupiter and along the solar polar orbit following the Jupiter encounter. The interconnection between these two magnetometers and their shared data processing unit is illustrated.

An evaluation of the accuracy of geomagnetic data obtained from an unattended, automated, quasi-absolute station

USGS Publications Warehouse

Herzog, D.C.

1990-01-01

A comparison is made of geomagnetic calibration data obtained from a high-sensitivity proton magnetometer enclosed within an orthogonal bias coil system, with data obtained from standard procedures at a mid-latitude U.S. Geological Survey magnetic observatory using a quartz horizontal magnetometer, a Ruska magnetometer, and a total field magnetometer. The orthogonal coil arrangement is used with the proton magnetometer to provide Deflected-Inclination-Deflected-Declination (DIDD) data from which quasi-absolute values of declination, horizontal intensity, and vertical intensity can be derived. Vector magnetometers provide the ordinate values to yield baseline calibrations for both the DIDD and standard observatory processes. Results obtained from a prototype system over a period of several months indicate that the DIDD unit can furnish adequate absolute field values for maintaining observatory calibration data, thus providing baseline control for unattended, remote stations. ?? 1990.

High Sensitivity Optically Pumped Quantum Magnetometer

PubMed Central

Tiporlini, Valentina; Alameh, Kamal

2013-01-01

Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

Ohmsett test of NOFI Vee-Sweep and NOFI 600S oilboom. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodwin, M.J.

1993-10-01

A NOFI Vee-Sweep and a NOFI 600S Oilboom, both manufactured by NOFI TROMSO A/S of Norway, were tested at the Ohmsett test tank in Leonardo, NJ. The V-Shaped Sweep is an oil boom designed for use with a skimmer at the apex of the V-Shaped configuration. Oil is funneled back to the skimmer by the converging sides of the V and concentrated for more efficient skimming. The 60 meter length of the sweep is doubled over to form the V and held in this shape by cross netting at the bottom of the skirt. The bottom netting is claimed tomore » help stabilize the oil in the sweep. The sweep was towed with a 700mm skirt depth and mouth opening of 16 meters. The mouth opening was reduced from the designed 19.8 meters to fit in the tow tank without causing excess blockage. The limiting towing speeds of the sweep were determined with and without oil present, in calm water and in small waves. The sweep's ability to conform to waves was also determined. Towing forces were measured. Limited data on oil loss rates were obtained. Testing confirmed the manufacturer's claim that the sweep can be towed at 1.0 and 1.4 knots with oil in calm water, based on the first loss of oil. The critical tow speed was found to be 3.4 to 3.6 knots in calm water. Oil booms, Tow tank testing.« less

Comparison of PAM Systems for Acoustic Monitoring and Further Risk Mitigation Application.

PubMed

Ludwig, Stefan; Kreimeyer, Roman; Knoll, Michaela

2016-01-01

We present results of the SIRENA 2011 research cruises conducted by the NATO Undersea Research Centre (NURC) and joined by the Research Department for Underwater Acoustics and Geophysics (FWG), Bundeswehr Technical Centre (WTD 71) and the Universities of Kiel and Pavia. The cruises were carried out in the Ligurian Sea. The main aim of the FWG was to test and evaluate the newly developed towed hydrophone array as a passive acoustic monitoring (PAM) tool for risk mitigation applications. The system was compared with the PAM equipment used by the other participating institutions. Recorded sounds were used to improve an automatic acoustic classifier for marine mammals, and validated acoustic detections by observers were compared with the results of the classifier.

Use of a SQUID array to detect T-cells with magnetic nanoparticles in determining transplant rejection

NASA Astrophysics Data System (ADS)

Flynn, Edward R.; Bryant, H. C.; Bergemann, Christian; Larson, Richard S.; Lovato, Debbie; Sergatskov, Dmitri A.

2007-04-01

Acute rejection in organ transplant is signaled by the proliferation of T-cells that target and kill the donor cells requiring painful biopsies to detect rejection onset. An alternative non-invasive technique is proposed using a multi-channel superconducting quantum interference device (SQUID) magnetometer to detect T-cell lymphocytes in the transplanted organ labeled with magnetic nanoparticles conjugated to antibodies specifically attached to lymphocytic ligand receptors. After a magnetic field pulse, the T-cells produce a decaying magnetic signal with a characteristic time of the order of a second. The extreme sensitivity of this technique, 10 5 cells, can provide early warning of impending transplant rejection and monitor immune-suppressive chemotherapy.

Dynamics of the Trapped Electron Phase Space Density in Relation to the Wave Activity in the Inner Magnetosphere

NASA Astrophysics Data System (ADS)

Vassiliadis, D.; Green, J.

2008-05-01

The phase space density fe of the radiation belt electron population is reconstructed based on measurements made by POLAR/HIST. The density peaks in invariant space (mu, K, L*) are shown to be responding to changes in the solar wind velocity and density, and the interplanetary magnetic field. We have associated specific types of storms with the appearance of peaks thereby producing a climatology of fe. We will report on comparing the phase space density changes during these storms to the ULF wave power in the inner magnetosphere remote- sensed by the IMAGE magnetometer array and related properties of the wave environment.

Alignment of a vector magnetometer to an optical prism

NASA Astrophysics Data System (ADS)

Dietrich, M. R.; Bailey, K. G.; O'Connor, T. P.

2017-05-01

A method for alignment of a vector magnetometer to a rigidly attached prism is presented. This enables optical comparison of the magnetometer axes to physical surfaces in the apparatus, and thus an absolute determination of the magnetic field direction in space. This is in contrast with more common techniques, which focus on precise determination of the relative angles between magnetometer axes, and so are more suited to measuring differences in the direction of magnetic fields. Here we demonstrate precision better than 500 μrad on a fluxgate magnetometer, which also gives the coil orthogonality errors to a similar precision. The relative sensitivity of the three axes is also determined, with a precision of about 5 ×10 -4 .

Sticky Bomb Detection With Other Implications For Vehicle Security

DTIC Science & Technology

2010-04-15

performance of two commercial magnetometers . The first was a handheld Walker Scientific Triaxial FluxGate Magnetometer with a 1 nanoTesla (nT) resolution...along each of 3 axes. The other ! !!!!!!!!!!!!!!!!!!!!!!!!!"#$%&’(!#)!*+,-./’(!01/$%.2,!34567!89:39!4;ɝɞ! ! 38! magnetometer was a PNI V2XE 2-axis...Argonne, IL is approximately 45,000 nT at the surface.) Readings from the Walker magnetometer were recorded manually from the liquid crystal

Achieving High Sensitivity in Cavity Optomechanical Magnetometry

DTIC Science & Technology

2014-03-08

magnetometers, but with microwatts of power consumption, and without the need for cryogenics. This project was to implement magnetometers at both micro- and...state-of-the-art in SQUID magnetometers, but with microwatts of power consumption, and without the need for cryogenics. This project was to implement...microwatts  of   power   and  at  room  temperature.  This  first  year  of  the  project  fabricated  new  magnetometer

A Magnetic Survey Of The MTJ(Mangatolu Triple Junction) Caldera On Lau Basin

NASA Astrophysics Data System (ADS)

Kwak, J.; Won, J.; Park, C.; Ko, Y.; Kim, C.; Jeong, E.; Yu, S.

2006-12-01

We have performed a magnetic survey to understand magnetic distribution and characteristics of the MTJ(Mangatolu Triple Junction) caldera. MTJ caldera(15°25'S, 174°00'W) is located between MTJ northeast extending branch which connects to the northeast Tonga trench[Wright et al, 2000] and the main line of Tofua volcanic arc. The caldera results from coupling between the crust of the Tonga microplate and the subducting Pacific plate[Macleod, 1996]. The MTJ is characterized severe deformation and neovolcanism[Parson and Tiffin, 1993], and has been reoriented during the Brunhes Chron[Zellmer et al, 2001]. Generally, low magnetization at crust is highly correlated with active hydrothermal vent field. The acidic and corrosive fluids that constitute marine hydrothermal vent systems can quickly alter or replace the iron-rich magnetic minerals, which reduce the magnetic remanence of the crustal rocks, in some cases to zero. Magnetic field data were observed by using high sensitivity proton magnetometer which is towed 300m behind the ship(R/V Onnuri). The data were first merged with the ship navigation. Then magnetic field was inverted for crustal magnetization using Parker[1974] inversion approach, which takes bathymetry into account assuming a constant layer thickness and then sufficient annihilator is added to magnetization solution to balance the positive and reverse polarity amplitudes. In this study, all inversions are calculated assuming a 500m source thickness.

Calibration of Magnetometers with GNSS Receivers and Magnetometer-Aided GNSS Ambiguity Fixing

PubMed Central

Henkel, Patrick

2017-01-01

Magnetometers provide compass information, and are widely used for navigation, orientation and alignment of objects. As magnetometers are affected by sensor biases and eventually by systematic distortions of the Earth magnetic field, a calibration is needed. In this paper, a method for calibration of magnetometers with three Global Navigation Satellite System (GNSS) receivers is presented. We perform a least-squares estimation of the magnetic flux and sensor biases using GNSS-based attitude information. The attitude is obtained from the relative positions between the GNSS receivers in the North-East-Down coordinate frame and prior knowledge of these relative positions in the platform’s coordinate frame. The relative positions and integer ambiguities of the periodic carrier phase measurements are determined with an integer least-squares estimation using an integer decorrelation and sequential tree search. Prior knowledge on the relative positions is used to increase the success rate of ambiguity fixing. We have validated the proposed method with low-cost magnetometers and GNSS receivers on a vehicle in a test drive. The calibration enabled a consistent heading determination with an accuracy of five degrees. This precise magnetometer-based attitude information allows an instantaneous GNSS integer ambiguity fixing. PMID:28594369

An Attitude Filtering and Magnetometer Calibration Approach for Nanosatellites

NASA Astrophysics Data System (ADS)

Söken, Halil Ersin

2018-04-01

We propose an attitude filtering and magnetometer calibration approach for nanosatellites. Measurements from magnetometers, Sun sensor and gyros are used in the filtering algorithm to estimate the attitude of the satellite together with the bias terms for the gyros and magnetometers. In the traditional approach for the attitude filtering, the attitude sensor measurements are used in the filter with a nonlinear vector measurement model. In the proposed algorithm, the TRIAD algorithm is used in conjunction with the unscented Kalman filter (UKF) to form the nontraditional attitude filter. First the vector measurements from the magnetometer and Sun sensor are processed with the TRIAD algorithm to obtain a coarse attitude estimate for the spacecraft. In the second phase the estimated coarse attitude is used as quaternion measurements for the UKF. The UKF estimates the fine attitude, and the gyro and magnetometer biases. We evaluate the algorithm for a hypothetical nanosatellite by numerical simulations. The results show that the attitude of the satellite can be estimated with an accuracy better than 0.5{°} and the computational load decreases more than 25% compared to a traditional UKF algorithm. We discuss the algorithm's performance in case of a time-variance in the magnetometer errors.

Low-Tc direct current superconducting quantum interference device magnetometer-based 36-channel magnetocardiography system in a magnetically shielded room

NASA Astrophysics Data System (ADS)

Qiu, Yang; Li, Hua; Zhang, Shu-Lin; Wang, Yong-Liang; Kong, Xiang-Yan; Zhang, Chao-Xiang; Zhang, Yong-Sheng; Xu, Xiao-Feng; Yang, Kang; Xie, Xiao-Ming

2015-07-01

We constructed a 36-channel magnetocardiography (MCG) system based on low-Tc direct current (DC) superconducting quantum interference device (SQUID) magnetometers operated inside a magnetically shielded room (MSR). Weakly damped SQUID magnetometers with large Steward-McCumber parameter βc (βc ≈ 5), which could directly connect to the operational amplifier without any additional feedback circuit, were used to simplify the readout electronics. With a flux-to-voltage transfer coefficient ∂ V/∂ Φ larger than 420 μV/Φ 0, the SQUID magnetometers had a white noise level of about 5.5 fT·Hz-1/2 when operated in MSR. 36 sensing magnetometers and 15 reference magnetometers were employed to realize software gradiometer configurations. The coverage area of the 36 sensing magnetometers is 210×210 mm2. MCG measurements with a high signal-to-noise ratio of 40 dB were done successfully using the developed system. Project supported by “One Hundred Persons Project” of the Chinese Academy of Sciences and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB04020200).

Calibration of Magnetometers with GNSS Receivers and Magnetometer-Aided GNSS Ambiguity Fixing.

PubMed

Henkel, Patrick

2017-06-08

Magnetometers provide compass information, and are widely used for navigation, orientation and alignment of objects. As magnetometers are affected by sensor biases and eventually by systematic distortions of the Earth magnetic field, a calibration is needed. In this paper, a method for calibration of magnetometers with three Global Navigation Satellite System (GNSS) receivers is presented. We perform a least-squares estimation of the magnetic flux and sensor biases using GNSS-based attitude information. The attitude is obtained from the relative positions between the GNSS receivers in the North-East-Down coordinate frame and prior knowledge of these relative positions in the platform's coordinate frame. The relative positions and integer ambiguities of the periodic carrier phase measurements are determined with an integer least-squares estimation using an integer decorrelation and sequential tree search. Prior knowledge on the relative positions is used to increase the success rate of ambiguity fixing. We have validated the proposed method with low-cost magnetometers and GNSS receivers on a vehicle in a test drive. The calibration enabled a consistent heading determination with an accuracy of five degrees. This precise magnetometer-based attitude information allows an instantaneous GNSS integer ambiguity fixing.

Adhesion at the interface in cured graphite fiber epoxy-amine resin composites

NASA Technical Reports Server (NTRS)

Needles, Howard L.; Alger, Kenneth W.; Okamoto, Robert

1987-01-01

The effect of high temperature curing on the interface between unsized or epoxy-sized graphite fiber tow and epoxy-amine resin was examined by scanning electron microscopy of compression and freeze fractured specimens. Little or no adhesion was found between the unsized graphite fiber tows and the epoxy-amine resin on curing at 165 C for 17 hrs. Epoxy-sized graphite fibers showed a similar lack of adhesion between the fiber tows and the epoxy-amine resin at 3 and 17 hr cures, although good penetration of the resin into the sized fiber tows had occurred. Interfacial bond strengths for the composites could not be effectively measured by compression fracture of specimens.

Influence of Tow Architecture on Compaction and Nesting in Textile Preforms

NASA Astrophysics Data System (ADS)

Yousaf, Z.; Potluri, P.; Withers, P. J.

2017-04-01

Transverse compression response of tows during processes such as vacuum infusion or autoclave curing has significant influence on resin permeability in fabrics as well as the laminate thickness, fibre volume fraction and tow orientations in the finished composite. This paper reports macro -scale deformations in dry fibre assemblies due to transverse compaction. In this study, influence of weave geometry and the presence of interlacements or stitches on the ply-level compaction as well as nesting have been investigated. 2D woven fabrics with a variety of interlacement patterns - plain, twill and sateen- as well as stitched Non-crimp (NCF) fabrics have been investigated for macro-level deformations. Compression response of single layer and multilayer stacks has been studied as a function of external pressure in order to establish nesting behaviour. It appears that the degree of individual ply compaction and degree of nesting between the plies are influenced by tow architectures. Inter-tow spacing and stitching thread thickness appears to influence the degree of nesting in non-crimp fabrics.

Modeling Geometry and Progressive Failure of Material Interfaces in Plain Weave Composites

NASA Technical Reports Server (NTRS)

Hsu, Su-Yuen; Cheng, Ron-Bin

2010-01-01

A procedure combining a geometrically nonlinear, explicit-dynamics contact analysis, computer aided design techniques, and elasticity-based mesh adjustment is proposed to efficiently generate realistic finite element models for meso-mechanical analysis of progressive failure in textile composites. In the procedure, the geometry of fiber tows is obtained by imposing a fictitious expansion on the tows. Meshes resulting from the procedure are conformal with the computed tow-tow and tow-matrix interfaces but are incongruent at the interfaces. The mesh interfaces are treated as cohesive contact surfaces not only to resolve the incongruence but also to simulate progressive failure. The method is employed to simulate debonding at the material interfaces in a ceramic-matrix plain weave composite with matrix porosity and in a polymeric matrix plain weave composite without matrix porosity, both subject to uniaxial cyclic loading. The numerical results indicate progression of the interfacial damage during every loading and reverse loading event in a constant strain amplitude cyclic process. However, the composites show different patterns of damage advancement.

Process for preparing tapes from thermoplastic polymers and carbon fibers

NASA Technical Reports Server (NTRS)

Chung, Tai-Shung (Inventor); Furst, Howard (Inventor); Gurion, Zev (Inventor); McMahon, Paul E. (Inventor); Orwoll, Richard D. (Inventor); Palangio, Daniel (Inventor)

1986-01-01

The instant invention involves a process for use in preparing tapes or rovings, which are formed from a thermoplastic material used to impregnate longitudinally extended bundles of carbon fibers. The process involves the steps of (a) gas spreading a tow of carbon fibers; (b) feeding the spread tow into a crosshead die; (c) impregnating the tow in the die with a thermoplastic polymer; (d) withdrawing the impregnated tow from the die; and (e) gas cooling the impregnated tow with a jet of air. The crosshead die useful in the instant invention includes a horizontally extended, carbon fiber bundle inlet channel, means for providing melted polymer under pressure to the die, means for dividing the polymeric material flowing into the die into an upper flow channel and a lower flow channel disposed above and below the moving carbon fiber bundle, means for applying the thermoplastic material from both the upper and lower channels to the fiber bundle, and means for withdrawing the resulting tape from the die.

Investigation of Submarine Groundwater Discharge and Preferential Groundwater Flow-paths in a Coastal Karst Area using towed Marine and Terrestrial Electrical Resistivity

NASA Astrophysics Data System (ADS)

O'connell, Y.; Daly, E.; Duffy, G.; Henry, T.

2012-12-01

Large volumes of groundwater, containing nutrients and contaminants enter the coastal waters of southern Galway Bay on the west coast of Ireland through submarine groundwater discharge (SGD). The SGD occurs through karstified Carboniferous limestone in a major karst region comprising the Burren and Gort Lowlands. The Carboniferous limestones have experienced extensive dissolution resulting in the development of an underground network of conduits and fissures that define a trimodal groundwater flow pattern across the region. Groundwater discharge to the sea in this area is exclusively intertidal and submarine. Storage in the karst is limited and typical winter rainfall conditions result in the karst system becoming saturated. Temporary lakes (turloughs) form in lowlying areas and act as large reservoirs which provide storage to enable the transmission of the large volumes of water in the system to the sea. Between 2010 and 2012, terrestrial and shallow marine geophysical surveying has been undertaken to investigate preferential groundwater flow-paths and SGD locations in order to quantify the groundwater-seawater interactions in this coastal karst system. A report into the groundwater system of this karst region following a major flood event proposed a conceptual conduit model defined by extensive water tracing, water level monitoring, hydrochemical sampling, geological mapping and drilling. Limited information about the dimensions of the conduits was known. Electrical resistivity tomography (ERT) profiling to depths of 100m below ground level, with multiple array configurations, has been carried out to investigate the modes of groundwater flow in to and out of both temporary and permanent freshwater lakes in the system. Towed dipole-dipole profiles have been recorded to investigate conduits beneath a permanent lake exhibiting a tidal influence despite its location 5.5 km from the seashore. The ERT data indicates significant variations in subsurface resistivities including very low resistivity features which have been modeled as large diameter conduits. Ongoing analysis of the data will allow more accurate conduit dimensions to be incorporated in to future groundwater flow models. In the shallow marine bays along the coast, towed ERT employing dipole-dipole and non-conventional modified Wenner arrays has been coupled with high-resolution digital chirp sub-bottom profiling. Combining the two techniques allows the determination of sediment, structural and lithological variations beneath the sea floor, delineating saturated sediment layers, till and bedrock horizons. Incorporation of the water column thickness and conductivity, recorded simultaneously with the ERT survey, constrains the inversion process. In addition, multiple layer boundaries interpreted from the sub-bottom profiling are incorporated in to the model, further constraining the inversion process. The combined inversion allows improved data interpretation to facilitate more accurate assessment of SGD locations.

Autonomous Sensors for Large Scale Data Collection

NASA Astrophysics Data System (ADS)

Noto, J.; Kerr, R.; Riccobono, J.; Kapali, S.; Migliozzi, M. A.; Goenka, C.

2017-12-01

Presented here is a novel implementation of a "Doppler imager" which remotely measures winds and temperatures of the neutral background atmosphere at ionospheric altitudes of 87-300Km and possibly above. Incorporating both recent optical manufacturing developments, modern network awareness and the application of machine learning techniques for intelligent self-monitoring and data classification. This system achieves cost savings in manufacturing, deployment and lifetime operating costs. Deployed in both ground and space-based modalities, this cost-disruptive technology will allow computer models of, ionospheric variability and other space weather models to operate with higher precision. Other sensors can be folded into the data collection and analysis architecture easily creating autonomous virtual observatories. A prototype version of this sensor has recently been deployed in Trivandrum India for the Indian Government. This Doppler imager is capable of operation, even within the restricted CubeSat environment. The CubeSat bus offers a very challenging environment, even for small instruments. The lack of SWaP and the challenging thermal environment demand development of a new generation of instruments; the Doppler imager presented is well suited to this environment. Concurrent with this CubeSat development is the development and construction of ground based arrays of inexpensive sensors using the proposed technology. This instrument could be flown inexpensively on one or more CubeSats to provide valuable data to space weather forecasters and ionospheric scientists. Arrays of magnetometers have been deployed for the last 20 years [Alabi, 2005]. Other examples of ground based arrays include an array of white-light all sky imagers (THEMIS) deployed across Canada [Donovan et al., 2006], oceans sensors on buoys [McPhaden et al., 2010], and arrays of seismic sensors [Schweitzer et al., 2002]. A comparable array of Doppler imagers can be constructed and deployed on the ground, to compliment the CubeSat data.

Alignment of a vector magnetometer to an optical prism.

PubMed

Dietrich, M R; Bailey, K G; O'Connor, T P

2017-05-01

A method for alignment of a vector magnetometer to a rigidly attached prism is presented. This enables optical comparison of the magnetometer axes to physical surfaces in the apparatus, and thus an absolute determination of the magnetic field direction in space. This is in contrast with more common techniques, which focus on precise determination of the relative angles between magnetometer axes, and so are more suited to measuring differences in the direction of magnetic fields. Here we demonstrate precision better than 500 μrad on a fluxgate magnetometer, which also gives the coil orthogonality errors to a similar precision. The relative sensitivity of the three axes is also determined, with a precision of about 5 × 10 -4 .

Sensitivity optimization of Bell-Bloom magnetometers by manipulation of atomic spin synchronization

NASA Astrophysics Data System (ADS)

Ranjbaran, M.; Tehranchi, M. M.; Hamidi, S. M.; Khalkhali, S. M. H.

2018-05-01

Many efforts have been devoted to the developments of atomic magnetometers for achieving the high sensitivity required in biomagnetic applications. To reach the high sensitivity, many types of atomic magnetometers have been introduced for optimization of the creation and relaxation rates of atomic spin polarization. In this paper, regards to sensitivity optimization techniques in the Mx configuration, we have proposed a novelty approach for synchronization of the spin precession in the Bell-Bloom magnetometers. We have utilized the phenomenological Bloch equations to simulate the spin dynamics when modulation of pumping light and radio frequency magnetic field were both used for atomic spin synchronization. Our results showed that the synchronization process, improved the magnetometer sensitivity respect to the classical configurations.

Optimization of multimagnetometer systems on a spacecraft

NASA Technical Reports Server (NTRS)

Neubauer, F. M.

1975-01-01

The problem of optimizing the position of magnetometers along a boom of given length to yield a minimized total error is investigated. The discussion is limited to at most four magnetometers, which seems to be a practical limit due to weight, power, and financial considerations. The outlined error analysis is applied to some illustrative cases. The optimal magnetometer locations, for which the total error is minimum, are computed for given boom length, instrument errors, and very conservative magnetic field models characteristic for spacecraft with only a restricted or ineffective magnetic cleanliness program. It is shown that the error contribution by the magnetometer inaccuracy is increased as the number of magnetometers is increased, whereas the spacecraft field uncertainty is diminished by an appreciably larger amount.

Advanced tow placement of composite fuselage structure

NASA Technical Reports Server (NTRS)

Anderson, Robert L.; Grant, Carroll G.

1992-01-01

The Hercules NASA ACT program was established to demonstrate and validate the low cost potential of the automated tow placement process for fabrication of aircraft primary structures. The program is currently being conducted as a cooperative program in collaboration with the Boeing ATCAS Program. The Hercules advanced tow placement process has been in development since 1982 and was developed specifically for composite aircraft structures. The second generation machine, now in operation at Hercules, is a production-ready machine that uses a low cost prepreg tow material form to produce structures with laminate properties equivalent to prepreg tape layup. Current program activities are focused on demonstration of the automated tow placement process for fabrication of subsonic transport aircraft fuselage crown quadrants. We are working with Boeing Commercial Aircraft and Douglas Aircraft during this phase of the program. The Douglas demonstration panels has co-cured skin/stringers, and the Boeing demonstration panel is an intricately bonded part with co-cured skin/stringers and co-bonded frames. Other aircraft structures that were evaluated for the automated tow placement process include engine nacelle components, fuselage pressure bulkheads, and fuselage tail cones. Because of the cylindrical shape of these structures, multiple parts can be fabricated on one two placement tool, thus reducing the cost per pound of the finished part.

Automated Finite Element Analysis of Elastically-Tailored Plates

NASA Technical Reports Server (NTRS)

Jegley, Dawn C. (Technical Monitor); Tatting, Brian F.; Guerdal, Zafer

2003-01-01

A procedure for analyzing and designing elastically tailored composite laminates using the STAGS finite element solver has been presented. The methodology used to produce the elastic tailoring, namely computer-controlled steering of unidirectionally reinforced composite material tows, has been reduced to a handful of design parameters along with a selection of construction methods. The generality of the tow-steered ply definition provides the user a wide variety of options for laminate design, which can be automatically incorporated with any finite element model that is composed of STAGS shell elements. Furthermore, the variable stiffness parameterization is formulated so that manufacturability can be assessed during the design process, plus new ideas using tow steering concepts can be easily integrated within the general framework of the elastic tailoring definitions. Details for the necessary implementation of the tow-steering definitions within the STAGS hierarchy is provided, and the format of the ply definitions is discussed in detail to provide easy access to the elastic tailoring choices. Integration of the automated STAGS solver with laminate design software has been demonstrated, so that the large design space generated by the tow-steering options can be traversed effectively. Several design problems are presented which confirm the usefulness of the design tool as well as further establish the potential of tow-steered plies for laminate design.

Nonlinear temperature compensation of fluxgate magnetometers with a least-squares support vector machine

NASA Astrophysics Data System (ADS)

Pang, Hongfeng; Chen, Dixiang; Pan, Mengchun; Luo, Shitu; Zhang, Qi; Luo, Feilu

2012-02-01

Fluxgate magnetometers are widely used for magnetic field measurement. However, their accuracy is influenced by temperature. In this paper, a new method was proposed to compensate the temperature drift of fluxgate magnetometers, in which a least-squares support vector machine (LSSVM) is utilized. The compensation performance was analyzed by simulation, which shows that the LSSVM has better performance and less training time than backpropagation and radical basis function neural networks. The temperature characteristics of a DM fluxgate magnetometer were measured with a temperature experiment box. Forty-five measured data under different magnetic fields and temperatures were obtained and divided into 36 training data and nine test data. The training data were used to obtain the parameters of the LSSVM model, and the compensation performance of the LSSVM model was verified by the test data. Experimental results show that the temperature drift of magnetometer is reduced from 109.3 to 3.3 nT after compensation, which suggests that this compensation method is effective for the accuracy improvement of fluxgate magnetometers.

Analytical balance-based Faraday magnetometer

NASA Astrophysics Data System (ADS)

Riminucci, Alberto; Uhlarz, Marc; De Santis, Roberto; Herrmannsdörfer, Thomas

2017-03-01

We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10-8 A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ɛ-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

Measurement and subtraction of Schumann resonances at gravitational-wave interferometers

NASA Astrophysics Data System (ADS)

Coughlin, Michael W.; Cirone, Alessio; Meyers, Patrick; Atsuta, Sho; Boschi, Valerio; Chincarini, Andrea; Christensen, Nelson L.; De Rosa, Rosario; Effler, Anamaria; Fiori, Irene; Gołkowski, Mark; Guidry, Melissa; Harms, Jan; Hayama, Kazuhiro; Kataoka, Yuu; Kubisz, Jerzy; Kulak, Andrzej; Laxen, Michael; Matas, Andrew; Mlynarczyk, Janusz; Ogawa, Tsutomu; Paoletti, Federico; Salvador, Jacobo; Schofield, Robert; Somiya, Kentaro; Thrane, Eric

2018-05-01

Correlated magnetic noise from Schumann resonances threatens to contaminate the observation of a stochastic gravitational-wave background in interferometric detectors. In previous work, we reported on the first effort to eliminate global correlated noise from the Schumann resonances using Wiener filtering, demonstrating as much as a factor of two reduction in the coherence between magnetometers on different continents. In this work, we present results from dedicated magnetometer measurements at the Virgo and KAGRA sites, which are the first results for subtraction using data from gravitational-wave detector sites. We compare these measurements to a growing network of permanent magnetometer stations, including at the LIGO sites. We show the effect of mutual magnetometer attraction, arguing that magnetometers should be placed at least one meter from one another. In addition, for the first time, we show how dedicated measurements by magnetometers near to the interferometers can reduce coherence to a level consistent with uncorrelated noise, making a potential detection of a stochastic gravitational-wave background possible.

Storm-generated bedforms and relict dissolution pits and channels on the Yucatan carbonate platform

NASA Astrophysics Data System (ADS)

Gulick, S. P.; Goff, J. A.; Stewart, H. A.; Perez-Cruz, L. L.; Davis, M. B.; Duncan, D.; Saustrup, S.; Sanford, J. C.; Fucugauchi, J. U.

2013-12-01

The Yucatan 2013 (cruise number 2013/4_ECORD) geophysical and geotechnical hazard site survey took place aboard the R/V Justo Sierra in April 2013. Our study was conducted within the Chicxulub impact crater, encompassing three potential IODP drilling sites. The survey was located ~32 km northwest of Progreso, Mexico; data acquired included ~15.6 km2 of complete multibeam bathymetry coverage, ~435 line km of side scan sonar and CHIRP data, 204 line kilometers of magnetometer data, and 194 line kilometers of surface tow boomer profiles. Based on these data, this portion of the Yucatan Shelf consists of flat-lying, hard limestone rock overlain by isolated ribbons of carbonate sand <1.0 m thick. These ribbons are oriented along NE-SW trends and have smaller scale orthogonal sand-waves (~20-100 m wavelengths and relief of ~0.2-0.6 m) on them. The sand waves are anisotropic with steeper slopes facing the NE. The larger scale morphology can be classified as longitudinal bedforms (ribbons), and the smaller scale transverse bedforms formed in response to a NE-directed flow. This flow direction is inconsistent with the ambient west-directed current conditions, and may therefore be indicative of storm-driven currents. Numerous dissolution pits, ~5-50m in diameter, ~0.2-0.5 m deep with steep (0.1-0.5 gradient) walls, are present in the bare rock regions of most of the study area. These occasionally are floored by rippled, highly reflective (coarse) sediments. We interpret these pits as representing karstic morphology formed during the last sub-aerial exposure of the study area interpreted to have occurred during Holocene times given the present day ~17 m average water depth. A sub-surface reflector imaged on the surface tow boomer data lies 1-3 m below the hard seafloor reflection (sand ribbons are below the vertical resolution of the surface tow boomer), which we interpret as a layer within the limestone bedrock. This reflector is flat-lying and undisturbed throughout the survey area. Therefore, none of these dissolution pits appear to be underlain by a cenote or sink hole. The NW sector of the survey area exhibits a more complex morphology than the alternating ribbon/bare rock morphology elsewhere, including linear scarps (up to ~1 m relief), deeper pitting (up to ~1 m relief), and sinuous, dendritic channeling (up to ~2 m relief). The geologic origin of these features will require further investigation. Sand drifts are present in this region, but are thinner and cover less area. These observations show the dominant modern sediment formation and transport processes on this starved platform are from large storms and hurricanes that place large regions of the platform at wave base. Remaining observed features were generated during times of lower sea level.

Continental-shelf Scale Passive Ocean AcousticWaveguide Remote Sensing of Marine Mammals and other Submerged Objects including Detection, Localization, and Classification

NASA Astrophysics Data System (ADS)

Wang, Delin

In this thesis, we develop the basics of the Passive Ocean Acoustic Waveguide Remote Sensing (POAWRS) technique for the instantaneous continental-shelf scale detection, localization and species classification of marine mammal vocalizations. POAWRS uses a large-aperture, densely sampled coherent hydrophone array system with orders of magnitude higher array gain to enhance signal-to-noise ratios (SNR) by coherent beamforming, enabling detection of underwater acoustic signals either two orders of magnitude more distant in range or lower in SNR than a single hydrophone. The ability to employ coherent spatial processing of signals with the POAWRS technology significantly improves areal coverage, enabling detection of oceanic sound sources over instantaneous wide areas spanning 100 km or more in diameter. The POAWRS approach was applied to analyze marine mammal vocalizations from diverse species received on a 160-element Office Naval Research Five Octave Research Array (ONR-FORA) deployed during their feeding season in Fall 2006 in the Gulf of Maine. The species-dependent temporal-spatial distribution of marine mammal vocalizations and correlation to the prey fish distributions have been determined. Furthermore, the probability of detection regions, source level distributions and pulse compression gains of the vocalization signals from diverse marine mammal species have been estimated. We also develop an approach for enhancing the angular resolution and improving bearing estimates of acoustic signals received on a coherent hydrophone array with multiple-nested uniformly-spaced subapertures, such as the ONR-FORA, by nonuniform array beamforming. Finally we develop a low-cost non-oil-filled towable prototype hydrophone array that consists of eight hydrophone elements with real-time data acquisition and 100 m tow cable. The approach demonstrated here will be applied in the development of a full 160 element POAWRS-type low-cost coherent hydrophone array system in the future.

Global nature of Pc 5 magnetic pulsation during the WHI observation campaign

NASA Astrophysics Data System (ADS)

Fujimoto, A.; Tokunaga, T.; Abe, S.; Uozumi, T.; Yoshikawa, A.; Yumoto, K.; Group, M.

2008-12-01

In conjunction with the activities of IHY(International Heliophysical Year), an international observation campaign was planned and carried out from March 20 to April 16 of 2008. The name of this campaign is Whole Heliosphere Interval (WHI). During WHI, the nations of the world worked together to collect relevant scientific data. As a result, there now exists an exceptionally good data set of multi-point ground-based and satellite magnetometer data for this time frame. There were no clear and outstanding geomagnetic storms during WHI, but there were some moderate geomagnetically active moments. For example, on March 26, Dst index decreased from 25 nT to -41 nT for 10 hours(1000 -1900 UT). The amplitude of Pc 5 pulsation in the frequency band between 1.67 and 6.67 mHz at the MAGDAS stations increased for few days after March 26. Using magnetometer data obtained globally from ULTIMA(Ultra Large Terrestrial International Magnetic Array) stations, we will investigate the occurrence and wave characteristics(amplitude, period and phase) of Pc 5 pulsations. Particularly high-latitude Pc 5 observed at THEMIS (the Time History of Events and Macroscopic Interactions during Substorms), CARISMA(Canadian Array for Realtime Investigations of Magnetic Activity) and McMaC (Mid-continent Magnetoseismic Chain) stations will be compared with equatorial-latitude Pc 5 observed at MAGDAS stations(TIR, DAV, YAP, ANC, EUS, ILR, and UT=LT+5h, +8h, +9h, -5h, -2h and 0h, respectively). Acknowledgment: MAGDAS data used in this paper were obtained in mutual collaborations with the following representatives of various organizations; Prof. Archana Bhattacharya(Indian Institute of Geomagnetism, TIR), Fr. Daniel McNamara(Manila Observatory, DAV), Dr. David Aranug(Weather Service Office YAP, YAP), Dr. Ronald Woodman Pollitt(Instituto Geofisico del Peru, ANC), Dr. Severino L. G. Dutra(Brazilian National Space Research Institute (INPE), EUS), Dr. A. Babatunde Rabiu(Federal University of Technology, ILR).

Continued Development of Meandering Winding Magnetometer (MWM (Register Trademark)) Eddy Current Sensors for the Health Monitoring, Modeling and Damage Detection of Composite Overwrapped Pressure Vessels

NASA Technical Reports Server (NTRS)

Russell, Richard; Wincheski, Russell; Jablonski, David; Washabaugh, Andy; Sheiretov, Yanko; Martin, Christopher; Goldfine, Neil

2011-01-01

Composite Overwrapped Pressure Vessels (COPVs) are used in essentially all NASA spacecraft, launch. vehicles and payloads to contain high-pressure fluids for propulsion, life support systems and science experiments. Failure of any COPV either in flight or during ground processing would result in catastrophic damage to the spacecraft or payload, and could lead to loss of life. Therefore, NASA continues to investigate new methods to non-destructively inspect (NDE) COPVs for structural anomalies and to provide a means for in-situ structural health monitoring (SHM) during operational service. Partnering with JENTEK Sensors, engineers at NASA, Kennedy Space Center have successfully conducted a proof-of-concept study to develop Meandering Winding Magnetometer (MWM) eddy current sensors designed to make direct measurements of the stresses of the internal layers of a carbon fiber composite wrapped COPV. During this study three different MWM sensors were tested at three orientations to demonstrate the ability of the technology to measure stresses at various fiber orientations and depths. These results showed good correlation with actual surface strain gage measurements. MWM-Array technology for scanning COPVs can reliably be used to image and detect mechanical damage. To validate this conclusion, several COPVs were scanned to obtain a baseline, and then each COPV was impacted at varying energy levels and then rescanned. The baseline subtracted images were used to demonstrate damage detection. These scans were performed with two different MWM-Arrays. with different geometries for near-surface and deeper penetration imaging at multiple frequencies and in multiple orientations of the linear MWM drive. This presentation will include a review of micromechanical models that relate measured sensor responses to composite material constituent properties, validated by the proof of concept study, as the basis for SHM and NDE data analysis as well as potential improvements including design changes to miniaturize and make the sensors durable in the vacuum of space

Simulated Tank Anti-Armor Gunnery System (STAGS-TOW).

DTIC Science & Technology

1983-05-01

to train TOW gunners. It is derived from a model previously developed for DRAGON. The system employs a terrain board with model enemy armored vehicles ...gunnery training. TOW is a crew-portable, heavy anti-tank weapon designed to attack and defeat armored vehicles and field fortifications. The missile is...a target area, converts the infrared energy to electrical signals and then to visible light and displays the visible light as a real-time scene for

Paresev 1 in Landing

NASA Image and Video Library

1962-02-05

Pilot and Paresev 1 preparing for a landing on the Rogers dry lakebed in 1962 at Edwards Air Force Base, California. The flight program began with ground tow tests. Several tows were made before liftoff was attempted to check the control rigging and to familiarize the pilot with the vehicle’s ground stability. As the pilot’s confidence and experience increased, tow speeds were also increased until liftoff was attained. Liftoff was at about 40 knots indicated airspeed (kias).

Micro-shimmy of towed structures in experimentally uncharted unstable parameter domain

NASA Astrophysics Data System (ADS)

Takács, Dénes; Stépán, Gábor

2012-11-01

In this paper, the lateral instability of towed structures (trailers, caravans and articulated buses) is investigated with special attention to the small amplitude lateral vibration that leads to a higher energy consumption in certain parameter domains. A low degree-of-freedom mechanical model of a shimmying towed tyre is used that describes the dynamics of the tyre-ground contact patch by the time delayed differential equation. Stability charts are calculated and the theoretically predicted linear unstable islands of small amplitude shimmy motions are validated by laboratory experiments. A tyre is towed by a relatively long caster, and its temperature and the input current of the conveyor belt are measured in order to show the increased value of the rolling resistance.

Development of a Magnetic Nanoparticle Susceptibility Magnitude Imaging Array

PubMed Central

Ficko, Bradley W.; Nadar, Priyanka M.; Hoopes, P. Jack; Diamond, Solomon G.

2014-01-01

There are several emerging diagnostic and therapeutic applications of magnetic nanoparticles (mNPs) in medicine. This study examines the potential for developing an mNP imager that meets these emerging clinical needs with a low cost imaging solution that uses arrays of digitally controlled drive coils in a multiple-frequency, continuous-wave operating mode and compensated fluxgate magnetometers. The design approach is described and a mathematical model is developed to support measurement and imaging. A prototype is used to demonstrate active compensation of up to 185 times the primary applied magnetic field, depth sensitivity up to 2.5 cm (p < 0.01), and linearity over 5 dilutions (R2 > 0.98, p <0.001). System frequency responses show distinguishable readouts for iron oxide mNPs with single magnetic domain core diameters of 10 nm and 40 nm, and multi-domain mNPs with a hydrodynamic diameter of 100 nm. Tomographic images show a contrast-to-noise ratio of 23 for 0.5 ml of 12.5 mg Fe/ml mNPs at 1 cm depth. A demonstration involving the injection of mNPs into pork sausage shows the potential for use in biological systems. These results indicate that the proposed mNP imaging approach can potentially be extended to a larger array system with higher-resolution. PMID:24504184

A Complete Cubesat Magnetometer System Project

NASA Technical Reports Server (NTRS)

Zesta, Eftyhia

2014-01-01

The objective of this work is to provide the center with a fully tested, flexible, low cost, miniaturized science magnetometer system applicable to small satellite programs, like Cubesats, and to rides of opportunity that do not lend themselves to the high integration costs a science magnetometer on a boom necessitates.

Magnetic heading reference

NASA Technical Reports Server (NTRS)

Garner, H. D. (Inventor)

1977-01-01

This invention employs a magnetometer as a magnetic heading reference for a vehicle such as a small aircraft. The magnetometer is mounted on a directional dial in the aircraft in the vicinity of the pilot such that it is free to turn with the dial about the yaw axis of the aircraft. The invention includes a circuit for generating a signal proportional to the northerly turning error produced in the magnetometer due to the vertical component of the earth's magnetic field. This generated signal is then subtracted from the output of the magnetometer to compensate for the northerly turning error.

The MAGSAT vector magnetometer: A precision fluxgate magnetometer for the measurement of the geomagnetic field

NASA Technical Reports Server (NTRS)

Acuna, M. H.; Scearce, C. S.; Seek, J.; Scheifele, J.

1978-01-01

A description of the precision triaxial fluxgate magnetometer to be flown aboard the MAGSAT spacecraft is presented. The instrument covers the range of + or - 64,000 nT with a resolution of + or - 0.5 nT, an intrinsic accuracy of + or - 0.001% of full scale and an angular alignment stability of the order of 2 seconds of arc. It was developed at NASA's Goddard Space Flight Center and represents the state-of-the-art in precision vector magnetometers developed for spaceflight use.

Alignment of a vector magnetometer to an optical prism

DOE PAGES

Dietrich, M. R.; Bailey, K. G.; O’Connor, T. P.

2017-05-12

A method for alignment of a vector magnetometer to a rigidly attached prism is presented. This enables optical comparison of the magnetometer axes to physical surfaces in the apparatus, and thus an absolute determination of the magnetic field direction in space. This is in contrast with more common techniques, which focus on precise determination of the relative angles between magnetometer axes, and so are more suited to measuring differences in the direction of magnetic fields. Here we demonstrate precision better than 500 μrad on a fluxgate magnetometer, which also gives the coil orthogonality errors to a similar precision. As amore » result, the relative sensitivity of the three axes is also determined, with a precision of about 5 ×10 –4.« less

Design and analysis of control system for VCSEL of atomic interference magnetometer

NASA Astrophysics Data System (ADS)

Zhang, Xiao-nan; Sun, Xiao-jie; Kou, Jun; Yang, Feng; Li, Jie; Ren, Zhang; Wei, Zong-kang

2016-11-01

Magnetic field detection is an important means of deep space environment exploration. Benefit from simple structure and low power consumption, atomic interference magnetometer become one of the most potential detector payloads. Vertical Cavity Surface Emitting Laser (VCSEL) is usually used as a light source in atomic interference magnetometer and its frequency stability directly affects the stability and sensitivity of magnetometer. In this paper, closed-loop control strategy of VCSEL was designed and analysis, the controller parameters were selected and the feedback error algorithm was optimized as well. According to the results of experiments that were performed on the hardware-in-the-loop simulation platform, the designed closed-loop control system is reasonable and it is able to effectively improve the laser frequency stability during the actual work of the magnetometer.

Seismomagnetic effects from the long-awaited 28 September 2004 M 6.0 parkfield earthquake

USGS Publications Warehouse

Johnston, M.J.S.; Sasai, Y.; Egbert, G.D.; Mueller, R.J.

2006-01-01

Precise measurements of local magnetic fields have been obtained with a differentially connected array of seven synchronized proton magnetometers located along 60 km of the locked-to-creeping transition region of the San Andreas fault at Parkfield, California, since 1976. The M 6.0 Parkfield earthquake on 28 September 2004, occurred within this array and generated coseismic magnetic field changes of between 0.2 and 0.5 nT at five sites in the network. No preseismic magnetic field changes exceeding background noise levels are apparent in the magnetic data during the month, week, and days before the earthquake (or expected in light of the absence of measurable precursive deformation, seismicity, or pore pressure changes). Observations of electric and magnetic fields from 0.01 to 20 Hz are also made at one site near the end of the earthquake rupture and corrected for common-mode signals from the ionosphere/magnetosphere using a second site some 115 km to the northwest along the fault. These magnetic data show no indications of unusual noise before the earthquake in the ULF band (0.01-20 Hz) as suggested may have preceded the 1989 ML 7.1 Loma Prieta earthquake. Nor do we see electric field changes similar to those suggested to occur before earthquakes of this magnitude from data in Greece. Uniform and variable slip piezomagnetic models of the earthquake, derived from strain, displacement, and seismic data, generate magnetic field perturbations that are consistent with those observed by the magnetometer array. A higher rate of longer-term magnetic field change, consistent with increased loading in the region, is apparent since 1993. This accompanied an increased rate of secular shear strain observed on a two-color EDM network and a small network of borehole tensor strainmeters and increased seismicity dominated by three M 4.5-5 earthquakes roughly a year apart in 1992, 1993, and 1994. Models incorporating all of these data indicate increased slip at depth in the region, and this may have played a role in the final occurrence of the 28 September 2004 M 6.0 Parkfield earthquake. The absence of electric and magnetic field precursors for this, and other earthquakes with M 5-7.3 elsewhere in the San Andreas fault system, indicates useful prediction of damaging earthquakes seems unlikely using these electromagnetic data.

M2-F1 in flight over lakebed on tow line

NASA Technical Reports Server (NTRS)

1963-01-01

After initial ground-tow flights of the M2-F1 using the Pontiac as a tow vehicle, the way was clear to make air tows behind a C-47. The first air tow took place on 16 August 1963. Pilot Milt Thompson found that the M2-F1 flew well, with good control. This first flight lasted less than two minutes from tow-line release to touchdown. The descent rate was 4,000 feet per minute. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

Freedom Star tows a barge with an SLWT into Port Canaveral for the first time

NASA Technical Reports Server (NTRS)

1998-01-01

Freedom Star, one of NASA's two solid rocket booster recovery ships, tows a barge containing the third Space Shuttle super lightweight external tank (SLWT) into Port Canaveral. This SLWT will be used to launch the orbiter Discovery on mission STS-95 in October. This first-time towing arrangement, part of a cost savings plan by NASA to prudently manage existing resources, began June 12 from the Michoud Assembly Facility in New Orleans where the Shuttle's external tanks are manufactured. The barge will now be transported up the Banana River to the LC-39 turn basin using a conventional tugboat. Previously, NASA relied on an outside contractor to provide external tank towing services at a cost of about $120,000 per trip. The new plan allows NASA's Space Flight Operations contractor, United Space Alliance (USA), to provide the same service directly to NASA using the recovery ships during their downtime between Shuttle launches. Studies show a potential savings of about $50,000 per trip. The cost of the necessary ship modifications should be paid back by the fourteenth tank delivery. The other recovery ship, Liberty Star, has also undergone deck strengthening enhancements and will soon have the necessary towing winch installed. The other recovery vessel, Liberty Star, has undergone deck strengthening enhancements along with Freedom Star and will soon have the necessary towing winch installed.

Analysing Harmonic Motions with an iPhone's Magnetometer

ERIC Educational Resources Information Center

Yavuz, Ahmet; Temiz, Burak Kagan

2016-01-01

In this paper, we propose an experiment for analysing harmonic motion using an iPhone's (or iPad's) magnetometer. This experiment consists of the detection of magnetic field variations obtained from an iPhone's magnetometer sensor. A graph of harmonic motion is directly displayed on the iPhone's screen using the "Sensor Kinetics"…

Autonomous Underwater Munitions and Explosives of Concern Detection System

DTIC Science & Technology

2015-03-01

Field Magnetometer ......................................................................... 19 5.3.2 Fluxgate Compass...through the vehicle control system. Magnetic measurements are sampled at 10 Hz. 5.3.2 Fluxgate Compass Located in the magnetometer module pressure...pitch, and roll) from the fluxgate compass and the total field magnetometer measurements are required for processing into the MagComp compensation

In situ triaxial magnetic field compensation for the spin-exchange-relaxation-free atomic magnetometer.

PubMed

Fang, Jiancheng; Qin, Jie

2012-10-01

The spin-exchange-relaxation-free (SERF) atomic magnetometer is an ultra-high sensitivity magnetometer, but it must be operated in a magnetic field with strength less than about 10 nT. Magnetic field compensation is an effective way to shield the magnetic field, and this paper demonstrates an in situ triaxial magnetic field compensation system for operating the SERF atomic magnetometer. The proposed hardware is based on optical pumping, which uses some part of the SERF atomic magnetometer itself, and the compensation method is implemented by analyzing the dynamics of the atomic spin. The experimental setup for this compensation system is described, and with this configuration, a residual magnetic field of strength less than 2 nT (±0.38 nT in the x axis, ±0.43 nT in the y axis, and ±1.62 nT in the z axis) has been achieved after compensation. The SERF atomic magnetometer was then used to verify that the residual triaxial magnetic fields were coincident with what were achieved by the compensation system.

Imperfection Insensitivity Analyses of Advanced Composite Tow-Steered Shells

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Farrokh, Babak; Stanford, Bret K.; Weaver, Paul M.

2016-01-01

Two advanced composite tow-steered shells, one with tow overlaps and another without overlaps, were previously designed, fabricated and tested in end compression, both without cutouts, and with small and large cutouts. In each case, good agreement was observed between experimental buckling loads and supporting linear bifurcation buckling analyses. However, previous buckling tests and analyses have shown historically poor correlation, perhaps due to the presence of geometric imperfections that serve as failure initiators. For the tow-steered shells, their circumferential variation in axial stiffness may have suppressed this sensitivity to imperfections, leading to the agreement noted between tests and analyses. To investigate this further, a numerical investigation was performed in this study using geometric imperfections measured from both shells. Finite element models of both shells were analyzed first without, and then, with measured imperfections that were then, superposed in different orientations around the shell longitudinal axis. Small variations in both the axial prebuckling stiffness and global buckling load were observed for the range of imperfections studied here, which suggests that the tow steering, and resulting circumferentially varying axial stiffness, may result in the test-analysis correlation observed for these shells.

Routes for GMR-Sensor Design in Non-Destructive Testing

PubMed Central

Pelkner, Matthias; Neubauer, Andreas; Reimund, Verena; Kreutzbruck, Marc; Schütze, Andreas

2012-01-01

GMR sensors are widely used in many industrial segments such as information technology, automotive, automation and production, and safety applications. Each area requires an adaption of the sensor arrangement in terms of size adaption and alignment with respect to the field source involved. This paper deals with an analysis of geometric sensor parameters and the arrangement of GMR sensors providing a design roadmap for non-destructive testing (NDT) applications. For this purpose we use an analytical model simulating the magnetic flux leakage (MFL) distribution of surface breaking defects and investigate the flux leakage signal as a function of various sensor parameters. Our calculations show both the influence of sensor length and height and that when detecting the magnetic flux leakage of μm sized defects a gradiometer base line of 250 μm leads to a signal strength loss of less than 10% in comparison with a magnetometer response. To validate the simulation results we finally performed measurements with a GMR magnetometer sensor on a test plate with artificial μm-range cracks. The differences between simulation and measurement are below 6%. We report on the routes for a GMR gradiometer design as a basis for the fabrication of NDT-adapted sensor arrays. The results are also helpful for the use of GMR in other application when it comes to measure positions, lengths, angles or electrical currents.

Magnetic monopole search with the MoEDAL test trapping detector

NASA Astrophysics Data System (ADS)

Katre, Akshay

2016-11-01

IMoEDAL is designed to search for monopoles produced in high-energy Large Hadron Collider (LHC) collisions, based on two complementary techniques: nucleartrack detectors for high-ionisation signatures and other highly ionising avatars of new physics, and trapping volumes for direct magnetic charge measurements with a superconducting magnetometer. The MoEDAL test trapping detector array deployed in 2012, consisting of over 600 aluminium samples, was analysed and found to be consistent with zero trapped magnetic charge. Stopping acceptances are obtained from a simulation of monopole propagation in matter for a range of charges and masses, allowing to set modelindependent and model-dependent limits on monopole production cross sections. Multiples of the fundamental Dirac magnetic charge are probed for the first time at the LHC.

NASA. Langley Research Center dry powder towpreg system

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Marchello, Joseph M.

1990-01-01

Dry powder polymer impregnated carbon fiber tows were produced for preform weaving and composite materials molding applications. In the process, fluidized powder is deposited on spread tow bundles and melted on the fibers by radiant heating to adhere the polymer to the fiber. Unit design theory and operating correlations were developed to provide the basis for scale up of the process to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed, resin feeder, and quality control system. Bench scale experiments, at tow speeds up to 50 cm/sec, demonstrated that process variables can be controlled to produce weavable LARC-TPI carbon fiber towpreg. The towpreg made by the dry powder process was formed into unidirectional fiber moldings and was woven and molded into preform material of good quality.

Polymer encapsulated microcavity optomechanical magnetometer

DOE PAGES

Zhu, Jiangang; Zhao, Guangming; Savukov, Igor; ...

2017-08-21

We demonstrate a magnetometer using polymer encapsulated whispering-gallery-mode microcavity actuated by a micro-magnet. The magnetic field induces force on the micro-magnet causing deformation in the polymer around the microcavity. Subsequently the microcavity detects the change in the refractive index of the polymer resulted from the deformation. This magnetometer works in the frequency range of hertz-to-kilohertz range and achieves a sensitivity of 880 pT/Hz 1/2 at 200 Hz in a micro-scale sensor volume. Polymer encapsulation of the magnetometer and fiber optical connection ensures environmental robustness and practicality of the sensor.

The Magsat precision vector magnetometer

NASA Technical Reports Server (NTRS)

Acuna, M. H.

1980-01-01

This paper examines the Magsat precision vector magnetometer which is designed to measure projections of the ambient field in three orthogonal directions. The system contains a highly stable and linear triaxial fluxgate magnetometer with a dynamic range of + or - 2000 nT (1 nT = 10 to the -9 weber per sq m). The magnetometer electronics, analog-to-digital converter, and digitally controlled current sources are implemented with redundant designs to avoid a loss of data in case of failures. Measurements are carried out with an accuracy of + or - 1 part in 64,000 in magnitude and 5 arcsec in orientation (1 arcsec = 0.00028 deg).

Search Coil vs. Fluxgate Magnetometer Measurements at Interplanetary Shocks

NASA Technical Reports Server (NTRS)

Wilson, L.B., III

2012-01-01

We present magnetic field observations at interplanetary shocks comparing two different sample rates showing significantly different results. Fluxgate magnetometer measurements show relatively laminar supercritical shock transitions at roughly 11 samples/s. Search coil magnetometer measurements at 1875 samples/s, however, show large amplitude (dB/B as large as 2) fluctuations that are not resolved by the fluxgate magnetometer. We show that these fluctuations, identified as whistler mode waves, would produce a significant perturbation to the shock transition region changing the interpretation from laminar to turbulent. Thus, previous observations of supercritical interplanetary shocks classified as laminar may have been under sampled.

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

49 CFR 392.63 - Towing or pushing loaded buses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS DRIVING OF... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

An improved Overhauser magnetometer for Earth's magnetic field observation

NASA Astrophysics Data System (ADS)

Fan, Shifang; Chen, Shudong; Zhang, Shuang; Guo, Xin; Cao, Qiong

2016-09-01

Overhauser magnetometer is a kind of high-precision devices for magnetostatic field measurement. It is widely used in geological survey, earth field variations, UXO detection etc. However, the original Overhauser magnetometer JOM-2 shows great shortcomings of low signal to noise ratio (SNR) and high power consumption, which directly affect the performance of the device. In order to increase the sensitivity and reduce power consumption, we present an improved Overhauser magnetometer. Firstly, compared with the original power board which suffers from heavy noise for improper EMC design, an improved power broad with 20mV peak to peak noise is presented in this paper. Then, the junction field effect transistor (JFET) is used as pre-amplifier in our new design, to overcome the higher current noise produced by the original instrumentation amplifier. By adjusting the parameters carefully low noise factor down to 0.5 dB can be obtained. Finally, the new architecture of ARM + CPLD is adopted to replace the original one with DSP+CPLD. So lower power consumption and greater flash memory can be realized. With these measures, an improved Overhauser magnetometer with higher sensitivity and lower power consumption is design here. The experimental results indicate that the sensitivity of the improved Overhauser magnetometer is 0.071nT, which confirms that the new magnetometer is sensitive to earth field measurement.

Magnetometer-only attitude and angular velocity filtering estimation for attitude changing spacecraft

NASA Astrophysics Data System (ADS)

Ma, Hongliang; Xu, Shijie

2014-09-01

This paper presents an improved real-time sequential filter (IRTSF) for magnetometer-only attitude and angular velocity estimation of spacecraft during its attitude changing (including fast and large angular attitude maneuver, rapidly spinning or uncontrolled tumble). In this new magnetometer-only attitude determination technique, both attitude dynamics equation and first time derivative of measured magnetic field vector are directly leaded into filtering equations based on the traditional single vector attitude determination method of gyroless and real-time sequential filter (RTSF) of magnetometer-only attitude estimation. The process noise model of IRTSF includes attitude kinematics and dynamics equations, and its measurement model consists of magnetic field vector and its first time derivative. The observability of IRTSF for small or large angular velocity changing spacecraft is evaluated by an improved Lie-Differentiation, and the degrees of observability of IRTSF for different initial estimation errors are analyzed by the condition number and a solved covariance matrix. Numerical simulation results indicate that: (1) the attitude and angular velocity of spacecraft can be estimated with sufficient accuracy using IRTSF from magnetometer-only data; (2) compared with that of RTSF, the estimation accuracies and observability degrees of attitude and angular velocity using IRTSF from magnetometer-only data are both improved; and (3) universality: the IRTSF of magnetometer-only attitude and angular velocity estimation is observable for any different initial state estimation error vector.

Method for Coating a Tow with an Electrospun Nanofiber

NASA Technical Reports Server (NTRS)

Kohlman, Lee W. (Inventor); Roberts, Gary D. (Inventor)

2015-01-01

Method and apparatus for enhancing the durability as well as the strength and stiffness of prepreg fiber tows of the sort used in composite materials are disclosed. The method involves adhering electrospun fibers onto the surface of such composite materials as filament-wound composite objects and the surface of prepreg fiber tows of the sort that are subsequently used in the production of composite materials of the filament-wound, woven, and braided sorts. The apparatus performs the methods described herein.

Imaging a Hydrate-Related Cold Vent Offshore Vancouver Island From Deep-Towed Multichannel Seismic Data

DTIC Science & Technology

2009-02-20

vent). 2500 2600 2700 Distance (m) 2800 2900 3000 1.791 Figure 11. Southeast-northwest seismic section, showing hydrate cap details from DTI 6. The...line DT16 Line DTI 6 continues as a long transit line extending to the north- west. The 1999 COAMS (Canadian Ocean Acoustic Measurement System) grid...inline IN26 is coincident with DTI 6 (Figure 1). A com- bination of the surface-towed seismic data and the deep-towed DTAGS data is needed to provide

Apparatus for Sizing and Rewinding Graphite Fibers

NASA Technical Reports Server (NTRS)

Wilson, M. L.; Stanfield, C. E.

1986-01-01

Equipment ideally suited for research and development of new sizing solutions. Designed expecially for applying thermoplastic sizing solutions to graphite tow consisting of 3,000 to 12,000 filaments per tow, but accommodates other solutions, filament counts, and materials other than graphite. Closed system containing highly volatile methylene chloride vapors. Also ventilation system directly over resin reservoir. Concept used to apply sizing compounds on fiber tows or yarn-type reinforcement materials used in composite technology. Sizing solutions consist of compounds compatible with thermosets as well as thermoplastics.

History of the TOW Missile System

DTIC Science & Technology

1977-10-01

pp. 1 .5 .4 & 1 .5 .5 . (2 ) L t r , DCG/LCS, I I C O M , t o CG, AMC, 29 Nar 65, s u b j : PEVA FY 65 APE P r o j AXMS 4220.X.32909...TOW). HDF. 3 8 ~ t r , C G , MICOM, t o CG, AMC, 23 J u l 65 , s u b j : PEVA FY 66 APE P r o j MCMS 4290.X.32947 (TOW). HDF. $1.7 m i l l

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baucom, R.M.; Marchello, J.M.

Thermoplastic prepregs of LARC-TPI have been produced in a fluidized bed unit on spread continuous fiber tows. The powders are melted on the fibers by radiant heating to adhere the polymer to the fiber. This process produces tow prepreg uniformly without imposing severe stress on the fibers or requiring long high temperature residence times for the polymer. Unit design theory and operating correlations have been developed to provide the basis for scale up to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed and resin feed systems.

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

Magnetic mapping of (carbonated) oceanic crust-mantle boundary: New insights from Linnajavri, northern Norway

NASA Astrophysics Data System (ADS)

Tominaga, M.; Beinlich, A.; Tivey, M.; Andrade Lima, E.; Weiss, B. P.

2012-12-01

The contribution of lower oceanic crust and upper mantle to marine magnetic anomalies has long been recognized, but the detailed magnetic character of this non-volcanic source layer remains to be fully defined. Here, we report preliminary results of a magnetic survey and source characterization of a "carbonated" oceanic Moho (petrological "Mohorovicic discontinuity") sequence observed at the Linnajavri Serpentinite Complex (LSC), northern Norway. The LSC is located at 67° 36'N and 16° 24'E within the upper Allochthon of the Norwegian Caledonides and represents a dismembered ophiolite. Particularly in the southern ("Ridoalggicohkka") area of the LSC, gabbro, serpentinite and its talc-carbonate (soapstone) and quartz-carbonate (listvenite) altered equivalents are extraordinarily well-exposed [1]. An intact oceanic Moho is exposed here, despite its complex tectonic setting. The small degree of arctic rock weathering (≤ 2 mm weathering surface) allowed for detailed regional-scale surface magnetic mapping across alteration fronts (serpentinite-soapstone; soapstone-listvenite) and lithological contacts (soapstone-gabbro). Magnetic mapping was conducted using a handheld 3-axis magnetometer, surface-towed resistivity meter and Teka surface magnetic susceptometer with sample spacing of 1 m. Geophysical field mapping was combined with petrological observations and scanning SQUID microscopy (SM) mapping conducted on thin sections from rock samples that were drilled along the survey lines. Regional scale magnetic mapping indicates that the total magnetic field across both the "carbonated" Moho and the soapstone-serpentinite interfaces show higher frequency changes in their magnetic anomaly character and amplitudes than the surface-towed resistivity data. SQUID microscopy mapping of both natural remanence magnetization (NRM) and anhysteretic remanence magnetization (ARM) on gabbro, serpentinite, soapstone, and listvenite samples, with a sensor-sample separation of ˜190 μm, show that the distribution of microscopically measurable ferromagnetic and possibly sulfide minerals produces a different bulk intensity for each of the rock types. SM vector magnetic field maps of these samples also reveal that the magnetization associated with these grains (observed as dipole-like fields in SM maps) is variable in direction from grain to grain, which may result from different alteration histories for each grain. These complex magnetization patterns acquired through thermal and chemical alteration history may explain the short wavelength magnetic anomalies observed along our traverse lines. [1] Beinlich, A., Plümper, O., Hövelmann, J., Austrheim, H. and Jamtveit, B. (2012), Terra Nova, in press.

Demonstration of an Enhanced Vertical Magnetic Gradient System for UXO

DTIC Science & Technology

2008-12-01

fluxgate magnetometers , data recording console, laser altimeter, and acoustic altimeters were tested to ensure proper operation and performance. The VG...Simultaneous Electromagnetic Induction and Magnetometer System WAA wide area assessment ACKNOWLEDGEMENTS We wish to express our sincere...sensors. The benefits of vertical gradient (VG) configurations in magnetometer systems are common knowledge, and these configurations are routinely

Field Testing, Installation, and Calibration of a new Data Acquisition System for the USGS-Stanford-Berkley Ultra-Low Frequency Electromagnetic (ULFEM) Array

NASA Astrophysics Data System (ADS)

Creasy, N.; Gardner, J.; Spritzer, J. M.; Keneally, I.; Glen, J. M.; McPhee, D.; Klemperer, S. L.

2013-12-01

Since 2006, Stanford University, USGS, and UC Berkeley collaboratively maintain five permanent stations, to measure electric and magnetic data from 0.01 to 40Hz. Each station consists of three orthogonal coil magnetometers and two orthogonal 100m electrodes. The acquisition of ULFEM data helps study possible correlations between electromagnetic fields and seismic events related to the San Andreas Fault system. The current data acquisition system uses a Quanterra Q330 analog-to-digital converter. In 2010, we began development of a new 24-bit digitizing system known as the ULFEM 2010 digitizer in order to replace the Q330. The design of the new recorder was to be more economical and better tailored to the ULFEM network by providing power, calibration, and improved protection from lightning. However, the prototype had many problems, including a daily phase shift, amplifying error, and a time delay of 15 seconds (Bowden, et al., AGU, 2010). Currently, comparative testing of an improved prototype, ULFEM 2013, and the Q330 is taking place at the Jasper Ridge ULFEM station. The ULFEM 2013 contains eight channels that record input from three coil magnetometers, four electrodes, and temperature. Testing is ongoing and involves comparing the coil magnetometer and electrode signals processed by the Q330 and ULFEM 2013 digitizer. Data from the two systems will be compared in the time and frequency domains, and analyses will include calculating error and cross correlations. The ULFEM 2013 digitizer provides power to the magnetometer sensors as well as a calibration coil system (CCS). Every 24 hours, the CCS sends a calibration signal to calibration induction coils fitted to each of the three orthogonal magnetometers with the aim of testing the sensors' sensitivity and accuracy. The CCS produces a frequency sweep of 0.08, 0.51, 5, and 10Hz, creating a field nearly ten times greater than the Earth's field. The CCS consists of open source hardware and an amplifying frequency generator. Another ongoing effort to calibrate the ULFEM stations uses ground motion produced by distant earthquakes. Because of our stations' relatively close proximity (approximately 70km apart), teleseismic earthquakes at epicentral distances produce near-identical long-period seismic arrivals at each ULFEM station. The ground motion generated by the surface waves of distant earthquakes causes displacement of the induction coils, inducing magnetic anomalies in the recorded data. Because the ground motion has nearly the same characteristics at each station, the magnetic anomalies observed should have similar amplitudes regardless of the station (though modulated by the local conductivity structure at each site). To identify these coseismic signals, magnetic data were compared against seismic data from each station. Magnetic signals are clearly visible due to passage of Love and Rayleigh waves from teleseismic earthquakes of magnitude >7.4 and their relative amplitudes provide additional confirmation of the stability of our coils and recording system prior to the installation of the CCS.

Sled Towing Acutely Decreases Acceleration Sprint Time.

PubMed

Wong, Megan A; Dobbs, Ian J; Watkins, Casey M; Barillas, Saldiam R; Lin, Anne; Archer, David C; Lockie, Robert G; Coburn, Jared W; Brown, Lee E

2017-11-01

Wong, MA, Dobbs, IJ, Watkins, C, Barillas, SR, Lin, A, Archer, DC, Lockie, RG, Coburn, JW, and Brown, LE. Sled towing acutely decreases acceleration sprint time. J Strength Cond Res 31(11): 3046-3051, 2017-Sled towing is a common form of overload training in sports to develop muscular strength for sprinting. This type of training leads to acute and chronic outcomes. Acute training potentially leads to postactivation potentiation (PAP), which is when subsequent muscle performance is enhanced after a preload stimulus. The purpose of this study was to determine differences between rest intervals after sled towing on acute sprint speed. Twenty healthy recreationally trained men (age = 22.3 ± 2.4 years, height = 176.95 ± 5.46 cm, mass = 83.19 ± 11.31 kg) who were currently active in a field sport twice a week for the last 6 months volunteered to participate. A maximal 30-meter (m) baseline (BL) body mass (BM) sprint was performed (with splits at 5, 10, 20, and 30 m) followed by 5 visits where participants sprinted 30 m towing a sled at 30% BM then rested for 2, 4, 6, 8, or 12 minutes. They were instructed to stand still during rest times. After the rest interval, they performed a maximal 30-m post-test BM sprint. Analysis of variance (ANOVA) revealed that post sled tow BM sprint times (4.47 ± 0.21 seconds) were less than BL times (4.55 ± 0.18 seconds) on an individualized rest interval basis. A follow-up 2 × 4 ANOVA showed that this decrease occurred only in the acceleration phase over the first 5 m (BL = 1.13 ± 0.08 seconds vs. Best = 1.08 ± 0.08 seconds), which may be the result of PAP and the complex relationship between fatigue and potentiation relative to the intensity of the sled tow and the rest interval. Therefore, coaches should test their athletes on an individual basis to determine optimal rest time after a 30-m 30% BM sled tow to enhance acute sprint speed.

Novel Handheld Magnetometer Probe Based on Magnetic Tunnelling Junction Sensors for Intraoperative Sentinel Lymph Node Identification

PubMed Central

Cousins, A.; Balalis, G. L.; Thompson, S. K.; Forero Morales, D.; Mohtar, A.; Wedding, A. B.; Thierry, B.

2015-01-01

Using magnetic tunnelling junction sensors, a novel magnetometer probe for the identification of the sentinel lymph node using magnetic tracers was developed. Probe performance was characterised in vitro and validated in a preclinical swine model. Compared to conventional gamma probes, the magnetometer probe showed excellent spatial resolution of 4.0 mm, and the potential to detect as few as 5 μg of magnetic tracer. Due to the high sensitivity of the magnetometer, all first-tier nodes were identified in the preclinical experiments, and there were no instances of false positive or false negative detection. Furthermore, these preliminary data encourage the application of the magnetometer probe for use in more complex lymphatic environments, such as in gastrointestinal cancers, where the sentinel node is often in close proximity to other non-sentinel nodes, and high spatial resolution detection is required. PMID:26038833

Developement of a Fluxgate Magnetometer for the KITSAT-3 Satellite

NASA Astrophysics Data System (ADS)

Hwang, S. H.; Lee, D. H.; Min, K. W.; Shin, Y. H.; Choi, C. R.; Nobuhito, O.

1997-12-01

The magnetometer is one of the most important payloads of scientific satellites to monitor the near-earth space environment. The electromagnetic variations of the space environment can be observed with the electric and magnetic field measurements. In practice, it is well known that the measurement of magnetic fields needs less technical complexities than that of electric fields in space. Therefore the magnetometer has long been recognized as one of the basic payloads for the scientific satellites. In this paper, we discuss the scientific fluxgate magnetometer which will be on board the KITSAT-3. The main circuit design of the present magnetometer is based on that of KISAT-1 and -2 but its facilities have been re-designed to improve the resolution to about 5nT for scientific purpose. The calibration and noise level test of this circuit have been performed at the laboratory of the Tierra Tecnica company in Japan.

ARC-1944-AA-6374

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51. Rear view of P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

Structural Assessment of Advanced Composite Tow-Steered Shells

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Stanford, Bret K.; Hrinda, Glenn A.; Wang, Zhuosong; Martin, Robert a.; Kim, H. Alicia

2013-01-01

The structural performance of two advanced composite tow-steered shells, manufactured using a fiber placement system, is assessed using both experimental and analytical methods. The fiber orientation angles vary continuously around the shell circumference from 10 degrees on the shell crown and keel, to 45 degrees on the shell sides. The two shells differ in that one shell has the full 24-tow course applied during each pass of the fiber placement system, while the second shell uses the fiber placement system s tow drop/add capability to achieve a more uniform shell wall thickness. The shells are tested in axial compression, and estimates of their prebuckling axial stiffnesses and bifurcation buckling loads are predicted using linear finite element analyses. These preliminary predictions compare well with the test results, with an average agreement of approximately 10 percent.

Tape Placement Head for Applying Thermoplastic Tape to an Object

NASA Technical Reports Server (NTRS)

Cope, Ralph D. (Inventor); Funck, Steve B. (Inventor); Gruber, Mark B. (Inventor); Lamontia, Mark A. (Inventor); Johnson, Anthony D. (Inventor)

2008-01-01

A tape placement head for applying thermoplastic tape to an object includes a heated feeder which guides the tape/tow to a heated zone. The heated zone has a line compactor having a single row of at least one movable heated member. An area compactor is located in the heated zone downstream from the line compactor. The area compactor includes a plurality of rows of movable feet which are extendable toward the tape/tow different distances with respect to each other to conform to the shape of the object. A shim is located between the heated compactors and the tape/tow. A chilled compactor is in a chilled zone downstream from the heated zone. The chilled zone includes a line chilled compactor and an area chilled compactor. A chilled shim is mounted between the chilled compactor and the tape/tow.

One-Dimensional Model for the Ultrasonic Response of Resin-Filled Gaps in Automated Tape Layup Composites

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Juarez, Peter D.

2017-01-01

Automated tow placement has become a widely used fabrication technique, especially for large aerospace structures. Robotic heads lay down strips (tows) of preimpregnated fiber along programmed paths. The intention is to lay adjacent tows abutted to one another, but sometimes a gap is left between a tow and the previously-placed tow. If a tow gap exists, it fills with resin during cure, forming a fiber-free volume. In immersion ultrasonic pulse-echo measurements of a cured laminate, the gap can be observed to produce a noticeable echo, without significantly attenuating the back-wall reflection of the laminate. To understand this behavior, we considered a one dimensional model of the composite laminate, with a thin layer having the ultrasonic sound speed and density of neat resin, sandwiched between two layers of material having the sound speed and density of fiber-reinforced composite and surrounded on both sides by water. Neglecting attenuation, we considered the transmission and reflection coefficients of each interface, as well as that of the thin resin layer. Using the initial water/composite reflection as a reference, we computed the relative magnitude of the back surface/water reflection in the presence and in the absence of a resin-only layer, as well as the relative magnitude of the reflection arising from a thin resin layer in composite. While the one-dimensional model did not fully match the measurements, it did qualitatively explain the observed behavior.

M2-F1 in flight during low-speed car tow

NASA Technical Reports Server (NTRS)

1963-01-01

The M2-F1 shown in flight during a low-speed car tow runs across the lakebed. Such tests allowed about two minutes to test the vehicle's handling in flight. NASA Flight Research Center (later redesignated the Dryden Flight Research Center) personnel conducted as many as 8 to 14 ground-tow flights in a single day either to test the vehicle in preparation for air tows or to train pilots to fly the vehicle before they undertook air tows. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

Next Generation HeliMag UXO Mapping Technology

DTIC Science & Technology

2010-01-01

Ancillary instrumentation records aircraft height above ground and attitude. A fluxgate magnetometer is used to allow for aeromagnetic compensation of... Magnetometer System WWII World War II WAA wide area assessment ACKNOWLEDGEMENTS This Next Generation HeliMag Unexploded Ordnance (UXO) Mapping...for deployment of seven total-field magnetometers on a Kevlar reinforced boom mounted on a Bell 206L helicopter. The objectives of this

Advanced UXO Discrimination using Magnetometry: Understanding Remanent Magnetization

DTIC Science & Technology

2009-09-01

moments of steel samples. The MRIP comprises six three-component fluxgate magnetometers symmetrically distributed around a rotating sample holder. Samples...comprises six three- component fluxgate magnetometers symmetrically distributed around a rotating sample holder. Samples are placed on the holder... fluxgate magnetometers symmetrically distributed around a rotating sample holder. Samples are placed on the holder and are slowly spun through two

Compact, Low-Noise Magnetic Sensor with Fluxgate (DC) and Induction (AC) Modes of Operation

DTIC Science & Technology

2009-07-01

induction sensor and the fluxgate magnetometer . ......................................... 2 Figure 3.1 - Impulse response of a 4” long coil (#6...Block diagram of the Year 2, Task 2 fluxgate magnetometer . ................................... 6 Figure 3.3 - FIS-prototype magnetic-field...and demonstrated an innovative dual-mode, fluxgate -induction sensor (FIS) that combines a fluxgate magnetometer and an electromagnetic (EM) induction

ArchaeoMapper Beta Test Report

DTIC Science & Technology

2008-06-01

instruments (Geoscan, Bartington, GSSI, etc.) are you familiar with? The Geoscan Fluxgate Magnetometer and the Goescan Resistance Meter 2. What software do...Magnetometry - Geoscan magnetometer , RM 15 Geoscan resistance meter, and GSSI SIR 20 Radar 2. What software do you typically use to process your...Geoscan, Bartington, GSSI, etc.) are you familiar with? Magnetometry - Geoscan magnetometer , RM 15 Geoscan resistance meter, and GSSI SIR 20 Radar

Detection of NMR signals with a radio-frequency atomic magnetometer.

PubMed

Savukov, I M; Seltzer, S J; Romalis, M V

2007-04-01

We demonstrate detection of proton NMR signals with a radio-frequency (rf) atomic magnetometer tuned to the NMR frequency of 62 kHz. High-frequency operation of the atomic magnetometer makes it relatively insensitive to ambient magnetic field noise. We obtain magnetic field sensitivity of 7 fT/Hz1/2 using only a thin aluminum shield. We also derive an expression for the fundamental sensitivity limit of a surface inductive pick-up coil as a function of frequency and find that an atomic rf magnetometer is intrinsically more sensitive than a coil of comparable size for frequencies below about 50 MHz.

Magnetometer bias determination and attitude determination for near-earth spacecraft

NASA Technical Reports Server (NTRS)

Lerner, G. M.; Shuster, M. D.

1979-01-01

A simple linear-regression algorithm is used to determine simultaneously magnetometer biases, misalignments, and scale factor corrections, as well as the dependence of the measured magnetic field on magnetic control systems. This algorithm has been applied to data from the Seasat-1 and the Atmosphere Explorer Mission-1/Heat Capacity Mapping Mission (AEM-1/HCMM) spacecraft. Results show that complete inflight calibration as described here can improve significantly the accuracy of attitude solutions obtained from magnetometer measurements. This report discusses the difficulties involved in obtaining attitude information from three-axis magnetometers, briefly derives the calibration algorithm, and presents numerical results for the Seasat-1 and AEM-1/HCMM spacecraft.

Analysing harmonic motions with an iPhone’s magnetometer

NASA Astrophysics Data System (ADS)

Yavuz, Ahmet; Kağan Temiz, Burak

2016-05-01

In this paper, we propose an experiment for analysing harmonic motion using an iPhone’s (or iPad’s) magnetometer. This experiment consists of the detection of magnetic field variations obtained from an iPhone’s magnetometer sensor. A graph of harmonic motion is directly displayed on the iPhone’s screen using the Sensor Kinetics application. Data from this application was analysed with Eureqa software to establish the equation of the harmonic motion. Analyses show that the use of an iPhone’s magnetometer to analyse harmonic motion is a practical and effective method for small oscillations and frequencies less than 15-20 Hz.

Magnetic mapping around Les Saintes islands (Lesser Antilles, Guadeloupe) for structural interpretation

NASA Astrophysics Data System (ADS)

Mercier de Lépinay, J.; Munschy, M.; Géraud, Y.; Diraison, M.; Navelot, V.; Verati, C.; Corsini, M.; Lardeaux, J. M.

2016-12-01

In Les Saintes archipelago, the outcrop analysis of Terre-de-Haut island allows to point out several fault systems and geological objects such as lava domes and lava flows. Moreover an exhumed geothermal paleo-system was identified and is thought to be an interesting analogue of the active geothermal system of Bouillante, Guadeloupe. To fully understand this area, the offshore continuation of the geological features is a major concern. The previously known onshore features are visible on airborne magnetic maps due to the highly magnetized material in Les Saintes archipelago. Moreover hydrothermal processes alter the magnetized minerals of volcanic rocks, creating a significant variation in the magnetic measurements. Therefore an adapted marine magnetic study can help the geological understanding of this particular area. In order to correctly link the offshore and onshore structures, the magnetic survey must be close enough to the shoreline and detailed enough so as to correctly outline the tectonic structures. An appropriate solution for such a survey was to use a magnetometer aboard a speedboat. Such a boat allows more navigation flexibility than a classic oceanic vessel towing a magnetometer; it can sail at higher speed on calm seas and closer to the shoreline. This kind of set up is only viable because the magnetic effect of the ship can be compensated using the same algorithms than those used for airborne magnetometry. Studies were implemented through the GEOTREF program which benefits from the support of both the ADEME and the French public funds "Investments for the future". The use of magnetic field transformations allows a large variety of structures to be highlighted, providing insights that help to build a general understanding of the nature and distribution of the magnetic sources. Using a reduction to the pole map operator we are able to prolong the volcanic structures at sea. The marine part of the paleo-geothermal system extension is also roughly delineated. Linear geological features like fault systems tend to be well revealed by the tilt angle operator. With this map transformation, the main known faults of Terre-de-Haut can be prolonged at sea. Moreover, the general directions of magnetic outlines (major and minor) are in agreement with the directions of geological structures of this area.

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System.

PubMed

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-08-31

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a "fuzzy mass" of tufted fibers into a regular mass of untwisted fibers, named "tow". During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

Freedom Star tows a barge with an SLWT into Port Canaveral for the first time

NASA Technical Reports Server (NTRS)

1998-01-01

Freedom Star, one of NASA's two solid rocket booster recovery ships, tows a barge containing the third Space Shuttle super lightweight external tank (SLWT) into Port Canaveral. This SLWT will be used to launch the orbiter Discovery on mission STS-95 in October. This first-time towing arrangement, part of a cost savings plan by NASA to prudently manage existing resources, began June 12 from the Michoud Assembly Facility in New Orleans where the Shuttle's external tanks are manufactured. The barge will now be transported up the Banana River to the LC-39 turn basin using a conventional tugboat. Previously, NASA relied on an outside contractor to provide external tank towing services at a cost of about $120,000 per trip. The new plan allows NASA's Space Flight Operations contractor, United Space Alliance (USA), to provide the same service directly to NASA using the recovery ships during their downtime between Shuttle launches. Studies show a potential savings of about $50,000 per trip. The cost of the necessary ship modifications should be paid back by the fourteenth tank delivery. The other recovery ship, Liberty Star, has also undergone deck strengthening enhancements and will soon have the necessary towing winch installed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

John J. Gangloff Jr; Shatil Sinha; Suresh G. Advani

The formation and transport of voids in composite materials remains a key research area in composite manufacturing science. Knowledge of how voids, resin, and fiber reinforcement propagate throughout a composite material continuum from green state to cured state during an automated tape layup process is key to minimizing defects induced by void-initiated stress concentrations under applied loads for a wide variety of composite applications. This paper focuses on modeling resin flow in a deforming fiber tow during an automated process of partially impregnated thermoset prepreg composite material tapes. In this work, a tow unit cell based model has been presentedmore » that determines the consolidation and impregnation of a thermoset prepreg tape under an input pressure profile. A parametric study has been performed to characterize the behavior of varying tow speed and compaction forces on the degree of consolidation. Results indicate that increased tow consolidation is achieved with slower tow speeds and higher compaction forces although the relationship is not linear. The overall modeling of this project is motivated to address optimization of the 'green state' composite properties and processing parameters to reduce or eliminate 'cured state' defects, such as porosity and de-lamination. This work is partially funded by the Department of Energy under Award number DE-EE0001367.« less

The low cost Proton Precession Magnetometer developed at the Indian Institute of Geomagnetism

NASA Astrophysics Data System (ADS)

Mahavarkar, P.; Singh, S.; Labde, S.; Dongre, V.; Patil, A.

2017-05-01

Proton magnetometers are the oldest scalar magnetometers. The first commercial units were produced in early 1960s as portable instruments. In continuation airborne instruments appeared with optimized speed of readings and sensitivity, large sensors etc. Later development of Overhauser and optically pumped magnetometers has eliminated Proton magnetometers from airborne surveys. However they remain very popular in various ground surveys and observatories. With this primary purpose of generating the ground based magnetic data, the Indian Institute of Geomagnetism (IIG) for the last 3 decades have been developing low cost Proton Precession Magnetometers (PPM). Beginning with the 1 nT PPM which has undergone several changes in design, the successor PM7 the advanced version has been successfully developed by the institute and is installed at various observatories of the institute. PM7 records the total field `F' with accuracy of 0.1 nT and a sampling rate of 10 seconds/sample. This article briefly discusses the design and development of this IIG make PM7 and compares the data recorded by this instrument with one of the commercially available Overhauser magnetometer in the world market. The quality of data recorded by PM7 is in excellent agreement with the Overhauser. With the available quality of data generated by this instrument, PM7 is an affordable PPM for scientific institutions, schools and colleges intending to carry out geomagnetic studies. The commercial cost of PM7 is ≈ 20% of the cost of Overhauser available in market.

Advanced helium magnetometer for space applications

NASA Technical Reports Server (NTRS)

Slocum, Robert E.

1987-01-01

The goal of this effort was demonstration of the concepts for an advanced helium magnetometer which meets the demands of future NASA earth orbiting, interplanetary, solar, and interstellar missions. The technical effort focused on optical pumping of helium with tunable solid state lasers. We were able to demonstrate the concept of a laser pumped helium magnetometer with improved accuracy, low power, and sensitivity of the order of 1 pT. A number of technical approaches were investigated for building a solid state laser tunable to the helium absorption line at 1083 nm. The laser selected was an Nd-doped LNA crystal pumped by a diode laser. Two laboratory versions of the lanthanum neodymium hexa-aluminate (LNA) laser were fabricated and used to conduct optical pumping experiments in helium and demonstrate laser pumped magnetometer concepts for both the low field vector mode and the scalar mode of operation. A digital resonance spectrometer was designed and built in order to evaluate the helium resonance signals and observe scalar magnetometer operation. The results indicate that the laser pumped sensor in the VHM mode is 45 times more sensitive than a lamp pumped sensor for identical system noise levels. A study was made of typical laser pumped resonance signals in the conventional magnetic resonance mode. The laser pumped sensor was operated as a scalar magnetometer, and it is concluded that magnetometers with 1 pT sensitivity can be achieved with the use of laser pumping and stable laser pump sources.

National automotive sampling system crashworthiness data system 1994-1996

DOT National Transportation Integrated Search

1999-10-01

This report focuses attention on occupants of those passenger vehicles that were towed from : the crash scene. NHTSA's National Automotive Sampling System (NASS)/ Crashworthiness : Data System (CDS) collects detailed information on towed passenger ve...

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

ARC-1944-AAL-6372

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51 Front view of P-51 & P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

ARC-1944-AAL-6371

NASA Image and Video Library

1944-08-31

Towing installations on P-51 and P-61 airplanes for propeller off tests on the P-51 Front view of P-51 & P-61 in towing position preparing for take off at NACA Ames Research Center, Moffett Field, California

ARC-1944-AAL-6373

NASA Image and Video Library

1944-08-31

Towing installations on P-51 airplane for propeller off tests on the P-51 Front view of P-51 in towing position with P-61A preparing for take off at NACA Ames Research Center, Moffett Field, California

LARC powder prepreg system

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Marchello, Joseph M.

1990-01-01

Thermoplastic prepregs of LARC-TPI have been produced in a fluidized bed unit on spread continuous fiber tows. The powders are melted on the fibers by radiant heating to adhere the polymer to the fiber. This process produces tow prepreg uniformly without imposing severe stress on the fibers or requiring long high temperature residence times for the polymer. Unit design theory and operating correlations have been developed to provide the basis for scale up to commercial operation. Special features of the operation are the pneumatic tow spreader, fluidized bed and resin feed systems.

Geophysical Studies in the Vicinity of the Warner Mountains and Surprise Valley, Northeast California, Northwest Nevada, and Southern Oregon

USGS Publications Warehouse

Ponce, David A.; Glen, Jonathan M.G.; Egger, Anne E.; Bouligand, Claire; Watt, Janet T.; Morin, Robert L.

2009-01-01

From May 2006 to August 2007, the U.S. Geological Survey (USGS) collected 793 gravity stations, about 102 line-kilometers of truck-towed and ground magnetometer data, and about 325 physical-property measurements in northeastern California, northwestern Nevada, and southern Oregon. Gravity, magnetic, and physical-property data were collected to study regional crustal structures and geology as an aid to understanding the geologic framework of the Surprise Valley geothermal area and, in general, geothermal systems throughout the Great Basin. The Warner Mountains and Surprise Valley mark the transition from the extended Basin and Range province to the unextended Modoc Plateau. This transition zone, in the northwestern corner of the Basin and Range, is relatively diffuse compared to other, more distinct boundaries, such as the Wasatch front in Utah and the eastern Sierran range front. In addition, this transition zone is the site of a geothermal system with potential for development, and previous studies have revealed a complex structural setting consisting of several obliquely oriented fault sets. As a result, this region has been the subject of several recent geological and geophysical investigations. The gravity and magnetic data presented here support and supplement those studies, and although the study area is composed predominantly of Tertiary volcanic rocks of the Modoc Plateau rocks, the physical properties of these and others rocks create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer subsurface geologic structure.

TOROID II

DTIC Science & Technology

2009-01-01

three axis fluxgate magnetometer , CMOS sun and star sensors, and a Kalman filter. The work and tasks that have been accomplished on the TOROID... magnetometer . The problem was found to be a missing ferrite bead which connects the 12V power supply to the op-amps which are used to appropriately...establish an overall operational timeline for TOROID. Testing and calibration was performed on the three-axis magnetometer which is primary attitude

Detection of J-coupling using atomic magnetometer

DOEpatents

Ledbetter, Micah P.; Crawford, Charles W.; Wemmer, David E.; Pines, Alexander; Knappe, Svenja; Kitching, John; Budker, Dmitry

2015-09-22

An embodiment of a method of detecting a J-coupling includes providing a polarized analyte adjacent to a vapor cell of an atomic magnetometer; and measuring one or more J-coupling parameters using the atomic magnetometer. According to an embodiment, measuring the one or more J-coupling parameters includes detecting a magnetic field created by the polarized analyte as the magnetic field evolves under a J-coupling interaction.

20. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA AERIAL VIEW OF THE SEAPLANE TOWING CHANNEL STRUCTURE. - NASA Langley Research Center, Seaplane Towing Channel, 108 Andrews Street, Hampton, Hampton, VA

Customized ATP towpreg. [Automated Tow Placement

NASA Technical Reports Server (NTRS)

Sandusky, Donald A.; Marchello, Joseph M.; Baucom, Robert M.; Johnston, Norman J.

1992-01-01

Automated tow placement (ATP) utilizes robotic technology to lay down adjacent polymer-matrix-impregnated carbon fiber tows on a tool surface. Consolidation and cure during ATP requires that void elimination and polymer matrix adhesion be accomplished in the short period of heating and pressure rolling that follows towpreg ribbon placement from the robot head to the tool. This study examined the key towpreg ribbon properties and dimensions which play a significant role in ATP. Analysis of the heat transfer process window indicates that adequate heating can be achieved at lay down rates as high as 1 m/sec. While heat transfer did not appear to be the limiting factor, resin flow and fiber movement into tow lap gaps could be. Accordingly, consideration was given to towpreg ribbon having uniform yet non-rectangular cross sections. Dimensional integrity of the towpreg ribbon combined with customized ribbon architecture offer great promise for processing advances in ATP of high performance composites.

Integral Textile Structure for 3-D CMC Turbine Airfoils

NASA Technical Reports Server (NTRS)

Marshall, David B. (Inventor); Cox, Brian N. (Inventor); Sudre, Olivier H. (Inventor)

2017-01-01

An integral textile structure for 3-D CMC turbine airfoils includes top and bottom walls made from an angle-interlock weave, each of the walls comprising warp and weft fiber tows. The top and bottom walls are merged on a first side parallel to the warp fiber tows into a single wall along a portion of their widths, with the weft fiber tows making up the single wall interlocked through the wall's thickness such that delamination of the wall is inhibited. The single wall suitably forms the trailing edge of an airfoil; the top and bottom walls are preferably joined along a second side opposite the first side and parallel to the radial fiber tows by a continuously curved section in which the weave structure remains continuous with the weave structure in the top and bottom walls, the continuously curved section being the leading edge of the airfoil.

Burst Testing of Triaxial Braided Composite Tubes

NASA Technical Reports Server (NTRS)

Salem, J. A.; Bail, J. L.; Wilmoth, N. G.; Ghosn, L. J.; Kohlman, L. W.; Roberts, G. D.; Martin, R. E.

2014-01-01

Applications using triaxial braided composites are limited by the materials transverse strength which is determined by the delamination capacity of unconstrained, free-edge tows. However, structural applications such as cylindrical tubes can be designed to minimize free edge effects and thus the strength with and without edge stresses is relevant to the design process. The transverse strength of triaxial braided composites without edge effects was determined by internally pressurizing tubes. In the absence of edge effects, the axial and transverse strength were comparable. In addition, notched specimens, which minimize the effect of unconstrained tow ends, were tested in a variety of geometries. Although the commonly tested notch geometries exhibited similar axial and transverse net section failure strength, significant dependence on notch configuration was observed. In the absence of unconstrained tows, failure ensues as a result of bias tow rotation, splitting, and fracture at cross-over regions.

Low-noise magnetometer based on inductance modulation in high-critical-temperature superconductor coil

NASA Astrophysics Data System (ADS)

Enpuku, Keiji; Matsuo, Masaaki; Yoshida, Yujiro; Yamashita, Shigeya; Sasayama, Teruyoshi; Yoshida, Takashi

2018-06-01

We developed a magnetometer based on inductance modulation of a coil made from a high-critical-temperature superconducting material. The coil inductance was modulated over time via a modulation current applied to a magnetic wire that was inserted into the coil. The magnetic field was then converted into a signal voltage using this time-dependent inductance. The relationship between magnetometer performance and the modulation current conditions was studied. Under appropriate conditions, the magnetometer had responsivity of 885 V/T. The magnetic field noise was 1.3 pT/Hz1/2 in the white noise region and 5.6 pT/Hz1/2 at f = 1 Hz.

Magnetogama: an open schematic magnetometer

NASA Astrophysics Data System (ADS)

Wahyudi; Khakhim, Nurul; Kuntoro, Tri; Mardiatno, Djati; Rakhman, Afif; Setyo Handaru, Anas; Akhmad Mufaqih, Adien; Marwan Irnaka, Theodosius

2017-09-01

Magnetogama is an open schematic hand-assembled fluxgate magnetometer. Compared to another magnetometer, Magnetogama has more benefit concerning its price and its ease of use. Practically Magnetogama can be utilized either in land or attached to an unmanned aerial vehicle (UAV). Magnetogama was designed to give open access to a cheap and accurate alternative to magnetometer sensor. Therefore it can be used as a standard design which is directly applicable to the low-budget company or education purposes. Schematic, code and several verification tests were presented in this article ensuring its reproducibility. Magnetogama has been tested with two kind of tests: a comparison with two nearest observatories at Learmonth (LRM) and Kakadu (KDU) and the response of magnetic substance.

Lunar surface magnetometer experiment

NASA Technical Reports Server (NTRS)

Dyal, P.; Parkin, C. W.; Sonett, C. P.

1972-01-01

The Apollo 15 lunar-surface magnetometer (LSM) is one of a network of magnetometers that have been deployed on the moon to study intrinsic remanent magnetic fields and global magnetic response of the moon to large-scale solar and terrestrial magnetic fields. From these field measurements, properties of the lunar interior such as magnetic permeability, electrical conductivity, and temperature can be calculated. In addition, correlation with solar-wind-spectrometer data allows study of the the solar-wind plasma interaction with the moon and, in turn, investigation of the resulting absorption of gases and accretion of an ionosphere. These physical parameters and processes determined from magnetometer measurements must be accounted for by comprehensive theories of origin and evolution of the moon and solar system.

Requirements for Coregistration Accuracy in On-Scalp MEG.

PubMed

Zetter, Rasmus; Iivanainen, Joonas; Stenroos, Matti; Parkkonen, Lauri

2018-06-22

Recent advances in magnetic sensing has made on-scalp magnetoencephalography (MEG) possible. In particular, optically-pumped magnetometers (OPMs) have reached sensitivity levels that enable their use in MEG. In contrast to the SQUID sensors used in current MEG systems, OPMs do not require cryogenic cooling and can thus be placed within millimetres from the head, enabling the construction of sensor arrays that conform to the shape of an individual's head. To properly estimate the location of neural sources within the brain, one must accurately know the position and orientation of sensors in relation to the head. With the adaptable on-scalp MEG sensor arrays, this coregistration becomes more challenging than in current SQUID-based MEG systems that use rigid sensor arrays. Here, we used simulations to quantify how accurately one needs to know the position and orientation of sensors in an on-scalp MEG system. The effects that different types of localisation errors have on forward modelling and source estimates obtained by minimum-norm estimation, dipole fitting, and beamforming are detailed. We found that sensor position errors generally have a larger effect than orientation errors and that these errors affect the localisation accuracy of superficial sources the most. To obtain similar or higher accuracy than with current SQUID-based MEG systems, RMS sensor position and orientation errors should be [Formula: see text] and [Formula: see text], respectively.

Testing FlowTracker2 Performance and Wading Rod Flow Disturbance in Laboratory Tow Tanks

NASA Astrophysics Data System (ADS)

Fan, X.; Wagenaar, D.

2016-12-01

The FlowTracker2 was released in February 2016 by SonTek (Xylem) to be a more feature-rich and technologically advanced replacement to the Original FlowTracker ADV. These instruments are Acoustic Doppler Velocimeters (ADVs) used for taking high-precision wading discharge and velocity measurements. The accuracy of the FlowTracker2 probe was tested in tow tanks at three different facilities: the USGS Hydrologic Instrumentation Facility (HIF), the Swiss Federal Institute for Metrology (METAS), and at the SonTek Research and Development facility. Multiple mounting configurations were examined, including mounting the ADV probe directly to the tow carts, and incorporating the two most-used wading rods for the FlowTracker (round and hex). Tow speeds ranged from 5cm/s to 1.5m/s, and different tow tank seeding schemes and wait times were examined. In addition, the performance of the FlowTracker2 probe in low Signal-to-Noise Ratio (SNR) environments was compared to the Original FlowTracker ADV. Results confirmed that the FlowTracker2 probe itself performed well within the 1%+0.25cm/s accuracy specification advertised. Tows using the wading rods created a reduced measured velocity by 1.3% of the expected velocity due to flow disturbance, a result similar to the Original FlowTracker ADV despite the change in the FlowTracker2 probe design. Finally, due to improvements in its electronics, the FlowTracker2's performance in low SNR tests exceeded that of the Original FlowTracker ADV, showing less standard error in these conditions compared to its predecessor.

Attitude and Trajectory Estimation Using Earth Magnetic Field Data

NASA Technical Reports Server (NTRS)

Deutschmann, Julie; Bar-Itzhack, Itzhack Y.

1996-01-01

The magnetometer has long been a reliable, inexpensive sensor used in spacecraft momentum management and attitude estimation. Recent studies show an increased accuracy potential for magnetometer-only attitude estimation systems. Since the Earth's magnetic field is a function of time and position, and since time is known quite precisely, the differences between the computer and measured magnetic field components, as measured by the magnetometers throughout the entire spacecraft orbit, are a function of both the spacecraft trajectory and attitude errors. Therefore, these errors can be used to estimate both trajectory and attitude. Traditionally, satellite attitude and trajectory have been estimated with completely separate system, using different measurement data. Recently, trajectory estimation for low earth orbit satellites was successfully demonstrated in ground software using only magnetometer data. This work proposes a single augmented extended Kalman Filter to simultaneously and autonomously estimate both spacecraft trajectory and attitude with data from a magnetometer and either dynamically determined rates or gyro-measured body rates.

Fluxgate vector magnetometers: Compensated multi-sensor devices for ground, UAV and airborne magnetic survey for various application in near surface geophysics

NASA Astrophysics Data System (ADS)

Gavazzi, Bruno; Le Maire, Pauline; Munschy, Marc; Dechamp, Aline

2017-04-01

Fluxgate 3-components magnetometer is the kind of magnetometer which offers the lightest weight and lowest power consumption for the measurement of the intensity of the magnetic field. Moreover, vector measurements make it the only kind of magnetometer allowing compensation of magnetic perturbations due to the equipment carried with it. Unfortunately, Fluxgate magnetometers are quite uncommon in near surface geophysics due to the difficulty to calibrate them precisely. The recent advances in calibration of the sensors and magnetic compensation of the devices from a simple process on the field led Institut de Physique du Globe de Strasbourg to develop instruments for georeferenced magnetic measurements at different scales - from submetric measurements on the ground to aircraft-conducted acquisition through the wide range offered by unmanned aerial vehicles (UAVs) - with a precision in the order of 1 nT. Such equipment is used for different kind of application: structural geology, pipes and UXO detection, archaeology.

The Z3 model of Saturns magnetic field and the Pioneer 11 vector helium magnetometer observations

NASA Technical Reports Server (NTRS)

Connerney, J. E. P.; Acuna, M. H.; Ness, N. F.

1984-01-01

Magnetic field observations obtained by the Pioneer 11 vector helium magnetometer are compared with the Z(sub 3) model magnetic field. These Pioneer 11 observations, obtained at close-in radial distances, constitute an important and independent test of the Z(sub 3) zonal harmonic model, which was derived from Voyager 1 and Voyager 2 fluxgate magnetometer observations. Differences between the Pioneer 11 magnetometer and the Z(sub 3) model field are found to be small (approximately 1%) and quantitatively consistent with the expected instrumental accuracy. A detailed examination of these differences in spacecraft payload coordinates shows that they are uniquely associated with the instrument frame of reference and operation. A much improved fit to the Pioneer 11 observations is obtained by rotation of the instrument coordinate system about the spacecraft spin axis by 1.4 degree. With this adjustment, possibly associated with an instrumental phase lag or roll attitude error, the Pioneer 11 vector helium magnetometer observations are fully consistent with the Voyager Z(sub 3) model.

Magnetogate: using an iPhone magnetometer for measuring kinematic variables

NASA Astrophysics Data System (ADS)

Kağan Temiz, Burak; Yavuz, Ahmet

2016-01-01

This paper presents a method to measure the movement of an object from specific locations on a straight line using an iPhone’s magnetometer. In this method, called ‘magnetogate’, an iPhone is placed on a moving object (in this case a toy car) and small neodymium magnets are arranged at equal intervals on one side of a straight line. The magnetometer sensor of the iPhone is switched on and then the car starts moving. The iPhone’s magnetometer is stimulated throughout its movement along a straight line. A ‘sensor Kinetics’ application on the iPhone saves the magnetic stimulations and produces a graph of the changing magnetic field near the iPhone. At the end of motion, data from the magnetometer is interpreted and peaks on the graph are detected. Thus, position-time changes can be analysed and comments about the motion of the object can be made. The position, velocity and acceleration of the object can be easily measured with this method.

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...

46 CFR 45.197 - Operational plan requirements for the Muskegon route.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (b) A list of mooring and docking facilities (with phone numbers) in St. Joseph, Holland, Grand Haven, and Muskegon, that can accommodate the tow. (c) A list of towing firms (with phone numbers) that have...