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1

Landsat Data Resources  

NSDL National Science Digital Library

This site from NASA provides a number of resources for obtaining Landsat digital data. Included are links for ordering Landsat 7 data as well as sources of Landsat 4, 5 and other related and heritage land remote sensing data.

Nasa

2

Overlay accuracy fundamentals  

NASA Astrophysics Data System (ADS)

Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to < 0.5nm, it becomes crucial to include also systematic error contributions which affect the accuracy of the metrology. Here we discuss fundamental aspects of overlay accuracy and a methodology to improve accuracy significantly. We identify overlay mark imperfections and their interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

2012-03-01

3

An Automatic Overlay Generator  

Microsoft Academic Search

We present an algorithm for automatically generating an overlay structure for a program, with the goal of reducing the primary storage requirements of that program. Subject to the constraints of intermodule dependences, the algorithm can either find a maximal overlay structure or find an overlay structure that, where possible, restricts the program to a specified amount of primary storage. Results

Ron Cytron; Paul G. Loewner

1986-01-01

4

Implementing declarative overlays  

Microsoft Academic Search

Overlay networks are used today in a variety of distributed systems ranging from file-sharing and storage systems to communication infrastructures. However, designing, building and adapting these overlays to the intended application and the target environment is a difficult and time consuming process.To ease the development and the deployment of such overlay networks we have implemented P2, a system that uses

Boon Thau Loo; Tyson Condie; Joseph M. Hellerstein; Petros Maniatis; Timothy Roscoe; Ion Stoica

2005-01-01

5

Landsat Earth Monitor.  

ERIC Educational Resources Information Center

|The uses of NASA's Landsat in the areas of cartography, flood control, agricultural inventory, land use mapping, water runoff, urban planning, erosion, geology, and water quality monitoring are illustrated. (BB)|

Haggerty, James J.

1979-01-01

6

NOAA should embrace Landsat  

NASA Astrophysics Data System (ADS)

“If only NOAA would embrace the Landsat satellite system, rather than trying to abandon it, then NOAA would be taking a giant step toward establishing its proper leadership role in global environmental science.” This statement was made by James H. Scheuer (D-N.Y.), chairman of the House Subcommittee on Natural Resources, Agriculture Research and Environment at a hearing on the National Oceanic and Atmospheric Administration's Fiscal Year 1992 budget, on April 11.Responding to a report by the Committee on Earth and Environmental Sciences (CEES), which stated that Landsat data is critical to the understanding of global warming, Scheuer is perplexed that NOAA would not want to fund Landsat 7 and that NOAA can have towering leadership and support of global climate research but tepid support of the Landsat part of the program. NOAA requested a 66% increase in funding for FY92 for the Global Climate Change Research program ($31 million total). Operational costs of Landsat 4 and 5, currently in orbit, and Landsat 6, scheduled for launch in May 1992, are part of NOAA's FY92 budget. Total cost, said NOAA comptroller, Rodney Weiher, will be almost $19 million, of which $9.15 million will come out of the NOAA budget and the remaining $9 million from other agencies.

Bush, Susan

7

Overlay Weaver: An overlay construction toolkit  

Microsoft Academic Search

A layered model of structured overlays has been proposed and it enabled devel- opment of a routing layer independently of higher-level services such as DHT and multicast. The routing layer has to include other part than a routing algorithm, which is essential for routing. It is routing process, which is common to various routing algorithms and can be decoupled from

Kazuyuki Shudo; Yoshio Tanaka; Satoshi Sekiguchi

2008-01-01

8

Landsat: Looking at Earth's Surface  

NASA Video Gallery

The Landsat program is the longest continuous global record of the Earth's surface, and continues to deliver both visually stunning and scientifically valuable images of our planet. > Landsat website > Download high-res video

Jim Wilson

2010-03-22

9

Multicast Overlay Network  

Microsoft Academic Search

Abstract Peer-to-Peer Overlay networks enabling an end-end application level-multicast service have drawn enormous attention. This paper proposes a self- organized -Multicast Overlay Network (-MON) that enables an efficient end-end application level multicast. The -MON is organized into MON- Clusters, where delta is the maximum physical number of hops between any two end-nodes in each MON-Cluster. Thus, end-users accessing from different

Khaled Ragab

2007-01-01

10

New holographic overlays  

NASA Astrophysics Data System (ADS)

This paper discusses a new type of holographic overlay, FLASHPRINT, which may be used in both security and packaging applications. Unlike the more common embossed holograms currently used, FLASHPRINT leads to reduced set-up costs and offers a simpler process. This reduces the long lead times characteristic of the existing technology and requires the customer to provide only two-dimensional artwork. The overlay material contains a covert 2-D image. The image may be switched on or off by simply tilting the overlay in a light source. The overlay is replayed in the 'on' position to reveal the encoded security message as a highly saturated gold colored image. This effect is operable for a wide range of lighting conditions and viewing geometries. In the 'off' position the overlay is substantially transparent. These features make the visual effect of the overlay attractive to incorporate into product design. They may be laminated over complex printed artwork such as labels and security passes without masking the printed message. When switched 'on' the image appears both sharp and more than seven times brighter than white paper. The image remains sharp and clear even in less favorable lighting conditions. Although the technique offers a low set-up cost for the customer, through its simplicity, it remains as technically demanding and difficult to counterfeit as any holographic process.

Hopwood, Anthony I.

1991-10-01

11

NOAA should embrace Landsat  

Microsoft Academic Search

``If only NOAA would embrace the Landsat satellite system, rather than trying to abandon it, then NOAA would be taking a giant step toward establishing its proper leadership role in global environmental science.'' This statement was made by James H. Scheuer (D-N.Y.), chairman of the House Subcommittee on Natural Resources, Agriculture Research and Environment at a hearing on the National

Susan Bush

1991-01-01

12

Quayle saves Landsat program  

NASA Astrophysics Data System (ADS)

With a last-minute budget reprieve from the Bush administration, Landsats 4 and 5, the sole public U.S. source of detailed satellite images of Earth, have another six months of life. The impending shutoff of the satellites on March 31 without an infusion of funds has focused attention on the public—private partnership that manages the Landsat program.EOSAT , Inc., the private corporation that operates Landsats 4 and 5, needs $9.4 million to maintain the satellites until the end of the fiscal year in October. As it has in previous years, t h e Reagan administration included no money in its FY 1989 budget to keep the spacecraft working, a n d the Bush administration has not amended that policy. Congress has restored operating funds in the past, but this time it was the National Space Council, headed by Vice President Dan Quayle, that released a statement saying that federal agencies that are many of the biggest customers for remote sensing data from the satellites will pay at least some of the costs. Under the plan the rest would be supplied by EOSAT, which markets Landsat data.

Maggs, William Ward

13

Concerns about Landsat 5 failure  

NASA Astrophysics Data System (ADS)

An electronic component on board the Landsat 5 Earth observation satellite has indicated signs of impending failure, and the U.S. Geological Survey (USGS) has stopped acquiring images from the satellite, the agency announced on 18 November. USGS engineers have suspended imaging activities for 90 days to explore options for restoring image transmissions from the satellite, which was launched in 1984 and has operated long beyond the 3 years it was designed to last. “This anticipated decline of Landsat 5 provides confirmation of the importance of the timely launch of the next Landsat mission and the need for an operational and reliable National Land Imaging System,” said Anne Castle, assistant secretary for water and science at the U.S. Department of the Interior. USGS is part of the Interior department. Landsat 7, launched in 1999 with a 5-year design life, remains in orbit. Landsat 8, the Landsat Data Continuity Mission, has a January 2013 scheduled launch.

Showstack, Randy

2011-12-01

14

Methodology for overlay mark selection  

NASA Astrophysics Data System (ADS)

It is known that different overlay mark designs will have different responses to process setup conditions. An overlay mark optimized for the 45nm technology node might not be suitable for wafers using 30nm or 20nm process technologies due to changes in lithography and process conditions. As overlay control specifications become tighter and tighter, the process engineer requires metrics beyond precision, tool-induced shift (TIS) and TIS variability to determine the optimal target design. In this paper, the authors demonstrate a novel, comprehensive methodology which employs source of variance (SOV) to help engineers select the best overlay marks to meet overlay control requirements.

Huang, Chin-Chou Kevin; Huang, Chao-Tien Healthy; Golotsvan, Anna; Tien, David; Chiu, Chui-Fu; Huang, Chun-Yen; Wu, Wen-Bin; Shih, Chiang-Lin

2011-03-01

15

Landsat sensor performance: history and current status  

Microsoft Academic Search

The current Thematic Mapper (TM) class of Landsat sensors began with Landsat-4, which was launched in 1982. This series continued with the nearly identical sensor on Landsat-5, launched in 1984. The final sensor in the series was the Landsat-7 Enhanced Thematic Mapper Plus (ETM+), which was carried into orbit in 1999. Varying degrees of effort have been devoted to the

Brian L. Markham; James C. Storey; Darrel L. Williams; James R. Irons

2004-01-01

16

Electrically conductive polymer concrete overlays  

NASA Astrophysics Data System (ADS)

The use of cathodic protection to prevent the corrosion of reinforcing steel in concrete structures has been well established. Application of a durable, skid-resistant electrically conductive polymer concrete overlay would advance the use of cathodic protection for the highway industry. Laboratory studies indicate that electrically conductive polymer concrete overlays using conductive fillers, such as calcined coke breeze, in conjunction with polyester or vinyl ester resins have resistivities of 1 to 10 ohm-cm. Both multiple-layer and premixed mortar-type overlays were made. Shear bond strengths of the conductive overlays to concrete substrates vary from 600 to 1300 psi, with the premixed overlays having bond strengths 50 to 100% higher than the multiple-layer overlays.

Fontana, J. J.; Webster, R. P.

1984-08-01

17

Electrically conductive polymer concrete overlays  

SciTech Connect

The use of cathodic protection to prevent the corrosion of reinforcing steel in concrete structures has been well established. Application of a durable, skid-resistant electrically conductive polymer concrete overlay would advance the use of cathodic protection for the highway industry. Laboratory studies indicate that electrically conductive polymer concrete overlays using conductive fillers, such as calcined coke breeze, in conjunction with polyester or vinyl ester resins have resistivities of 1 to 10 ohm-cm. Both multiple-layer and premixed mortar-type overlays have been made. Shear bond strengths of the conductive overlays to concrete substrates vary from 600 to 1300 psi, with the premixed overlays having bond strengths 50 to 100% higher than the multiple-layer overlays.

Fontana, J.J.; Webster, R.P.

1984-08-01

18

Landsat electron beam recorder  

NASA Astrophysics Data System (ADS)

A minicomputer-controlled electron beam recorder (EBR) presently in use at the Brazilian Government's Institute De Pesquisas Espaclais (INPE) satellite ground station is described. This 5-in.-film-size EBR is used to record both Landsat and SPOT satellite imagery in South America. A brief electron beam recorder technology review is presented. The EBR is capable of recording both vector and text data from computer-aided design, publishing, and line art systems and raster data from image scanners, raster image processors (RIPS), halftone/screen generators, and remote image sensors. A variety of image formats may be recorded on numerous film sizes (16 mm, 35 mm, 70 mm, 105 mm, 5-in, 5.5-in., and 9.5-in.). These recordings are used directly or optically enlarged depending on the final product.

Grosso, P. F.; Whitley, J. P.

19

Evaluation of the Cargill Safelane Surface Overlay.  

National Technical Information Service (NTIS)

A recent development in polymer concrete overlays is the Cargill SafeLane surface overlay (SafeLane overlay). The 3/8-in-thick overlay is constructed with epoxy and broadcast aggregates, as are typical multiple-layer epoxy overlays that are used to provid...

D. S. Roosevelt D. W. Mokarem E. D. Izeppi G. W. Flintsch M. M. Sprinkel

2009-01-01

20

Monitoring Water Quality from Landsat.  

National Technical Information Service (NTIS)

Water quality monitoring possibilities from LANDSAT were demonstrated both for direct readings of reflectances from the water and indirect monitoring of changes in use of land surrounding Swift Creek Reservoir in a joint project with the Virginia State Wa...

J. L. Barker

1975-01-01

21

25 Years of Landsat 5  

NASA Video Gallery

Twenty-two years beyond its primary mission lifetime, Landsat 5 is still going strong. It has charted urban growth in Las Vegas, monitored fire scars in Yellowstone National Park, and tracked the retreat of a Greenland glacier.

NASA - nasa.gov

2010-03-10

22

Landsat Data as a Tool for the Geosciences.  

ERIC Educational Resources Information Center

Applications of the Landsat Thematic Mapper in the fields of pedology, geology, and geomorphology are described. The history of the Landsat program and Landsat products are discussed. Illustrations of different Landsat views are presented. (CW)

Cary, Tina

1990-01-01

23

Some Observations About LANDSAT Digital Analysis.  

National Technical Information Service (NTIS)

Several hypotheses concerning LANDSAT data are analyzed. These hypotheses are: (1) LANDSAT does not discriminate vegetation types, but mostly sees chlorophyl and canopy cover. (2) A majority of the features in the ground scene possess linearly proportiona...

R. R. Jayroe

1978-01-01

24

Defending against eclipse attacks on overlay networks  

Microsoft Academic Search

Overlay networks are widely used to deploy functionality at edge nodes without changing network routers. Each node in an overlay network maintains pointers to a set of neighbor nodes. These pointers are used both to maintain the overlay and to implement application functionality, for example, to locate content stored by overlay nodes. If an attacker controls a large fraction of

Atul Singh; Miguel Castro; Peter Druschel; Antony I. T. Rowstron

2004-01-01

25

Strategies of Conflict in Coexisting Streaming Overlays  

Microsoft Academic Search

In multimedia applications such as IPTV, it is nat- ural to accommodate multiple coexisting peer-to-peer streaming overlays, corresponding to channels of programming. With coex- isting streaming overlays, one wonders how these overlays may ef- ficiently share the available upload bandwidth on peers, in order to satisfy the required streaming rate in each overlay, as well as to minimize streaming costs.

Chuan Wu; Baochun Li

2007-01-01

26

Overlay similarity: a new overlay index for metrology tool and scanner overlay fingerprint methodology  

NASA Astrophysics Data System (ADS)

For different CD metrologies like average CD from CD SEM and optical CD (OCD) from scatterometry, CD point-to-point R2 has been well adopted as the CD correlation index. For different overlay metrologies like image-based box-in-box overlay and scatterometry-based overlay, we propose the cosine similarity as the correlation index of overlay. The cosine similarity is a measure of similarity between two vectors of n dimensions by finding the cosine of the angle between them, often used to compare documents in text mining. It has been widely used in web and document search engines and can be used as the similarity index of overlay tool-to-tool matching and scanner tool-to-tool or day-to-day fingerprint. In this paper, we demonstrate that the cosine similarity has a very high sensitivity to the overly tool performance. We compared the similarities of three generations (A1, A2, A3) of the overlay tools of venders A and B and found that after target re-training and TIS correction on each tool A1 similarity to A3 can be improved from 0.9837 to 0.9951. Overlay point-to-point matching with A3 vs. A1 can be reduced from 4.8 to 2.1 nm. The tool precision similarities, i.e. tool self best similarity, for A1, A2, A3 and B are 0.9986, 0.9990, 0.9995, and 0.9994 respectively. From this table, we demonstrate that we can use old-generation overlay tool with suitable hardware maintenance, to match to the latest-generation overlay tool.

Ke, Chih-Ming; Kao, Ching-Pin; Wang, Yu-Hsi; Hu, Jimmy; Chang, Chen-Yu; Tsai, Ya-Jung; Yen, Anthony; Lin, Burn J.

2009-03-01

27

Reflection Cracking in Bituminous Overlays.  

National Technical Information Service (NTIS)

Nine different treatments to the pavement were included in the design of an Interstate project in Colorado in anticipation of finding a method of reducing or eliminating reflection cracking through bituminous overlays. Each treatment is represented by two...

D. E. Donnelly P. J. McCabe H. N. Swanson

1976-01-01

28

Continuity of Landsat observations: Short term considerations  

USGS Publications Warehouse

As of writing in mid-2010, both Landsat-5 and -7 continue to function, with sufficient fuel to enable data collection until the launch of the Landsat Data Continuity Mission (LDCM) scheduled for December of 2012. Failure of one or both of Landsat-5 or -7 may result in a lack of Landsat data for a period of time until the 2012 launch. Although the potential risk of a component failure increases the longer the sensor's design life is exceeded, the possible gap in Landsat data acquisition is reduced with each passing day and the risk of Landsat imagery being unavailable diminishes for all except a handful of applications that are particularly data demanding. Advances in Landsat data compositing and fusion are providing opportunities to address issues associated with Landsat-7 SLC-off imagery and to mitigate a potential acquisition gap through the integration of imagery from different sensors. The latter will likely also provide short-term, regional solutions to application-specific needs for the continuity of Landsat-like observations. Our goal in this communication is not to minimize the community's concerns regarding a gap in Landsat observations, but rather to clarify how the current situation has evolved and provide an up-to-date understanding of the circumstances, implications, and mitigation options related to a potential gap in the Landsat data record. ?? 2010.

Wulder, M. A.; White, J. C.; Masek, J. G.; Dwyer, J.; Roy, D. P.

2011-01-01

29

Overlay welding irradiated stainless steel  

NASA Astrophysics Data System (ADS)

An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to (n,alpha) reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

Kanne, W. R.; Chandler, G. T.; Nelson, D. Z.; Franco-Ferreira, E. A.

30

Coloured overlays, text, and texture.  

PubMed

In four studies children were asked to read aloud a passage of randomly ordered common words with and without a coloured sheet of plastic (overlay) placed upon the page. The children's rate of reading increased with the overlay, for some children more than for others. The children were also asked to undertake a test of texture segmentation in which targets consisting of a structured texture had to be distinguished from within a random background texture. The texture segmentation was improved when the overlay was used, again for some children more than for others. The improvement in texture segmentation was, in general, correlated with the improvement in rate of reading. Slower readers were generally poorer at texture segmentation. The implications for reading, for texture segmentation, and for clinical tests of vision are discussed. PMID:10664760

Wilkins, A; Lewis, E

1999-01-01

31

Overlay welding irradiated stainless steel  

SciTech Connect

An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,{alpha} reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

Kanne, W.R.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

1993-08-01

32

Overlay metrology at the crossroads  

NASA Astrophysics Data System (ADS)

The introduction of new techniques such as double patterning will reduce overlay process tolerance much faster than the rate at which critical feature dimensions are shrinking. In order to control such processes measurements with uncertainties under 0.4nm are desirable today and will become essential within the next few years. This very small error budget leads to questions about the capability of the imaging technology used in overlay tools today and to evaluation of potential replacement techniques. In this paper we will show that while imaging technology is in principle capable of meeting this requirement, the real uncertainty in overlay within devices falls well short of the levels needed. A proper comparison between techniques needs to focus on all of the possible sources of error, and especially those that cannot be simply reduced by calibration or by repeating measurements. On that basis there are more significant problems than the relative capability of different measurement techniques. We will discuss a method by which overlay within the device area can be controlled to the required tolerance.

Smith, Nigel P.; Binns, Lewis A.; Plambeck, Albert; Heidrich, Kevin

2008-04-01

33

32nm overlay improvement capabilities  

NASA Astrophysics Data System (ADS)

The industry is facing a major challenge looking forward on the technology roadmap with respect to overlay control. Immersion lithography has established itself as the POR for 45nm and for the next few nodes. As the gap closes between scanner capability and device requirements new methodologies need to be taken into consideration. Double patterning lithography is an approach that's being considered for 32 and below, but it creates very strict demands for overlay performance. The fact that a single layer device will need to be patterned using two sequential single processes creates a strong coupling between the 1st and 2nd exposure. The coupling effect during the double patterning process results in extremely tight tolerances for overlay error and scanner capabilities. The purpose of this paper is to explore a new modeling method to improve lithography performance for the 32nm node. Not necessarily unique for double patterning, but as a general approach to improve overlay performance regardless of which patterning process is implemented. We will achieve this by performing an in depth source of variance analysis of current scanner performance and project the anticipated improvements from our new modeling approach. Since the new modeling approach will involve 2nd and 3rd order corrections we will also provide and analysis that outlines current metrology capabilities and sampling optimizations to further expand the opportunities of an efficient implementation of such approach.

Eichelberger, Brad; Huang, Kevin; O'Brien, Kelly; Tien, David; Tsai, Frank; Minvielle, Anna; Singh, Lovejeet; Schefske, Jeffrey

2008-03-01

34

Landsat-7 and Landsat-5 thermal band calibration updates  

NASA Astrophysics Data System (ADS)

Landsat-7 ETM+, launched in April 1999, and Landsat-5 TM, launched in 1984, both have a single thermal band. Both instruments' thermal band calibrations have been updated: ETM+ in 2001 for a pre-launch calibration error and TM in 2007 for data acquired since the current era of vicarious calibration has been in place (1999). This year, the vicarious calibration teams have made regular collects of very hot targets, and have been able to make use of archived buoy data to extend the TM calibration back in time. The new data has made it clear that both instruments require slight adjustments in their thermal calibration coefficients. These new coefficients will be generated and put into the operational processing system to remove the calibration errors. The JPL vicarious calibration team has long operated automated buoys on Lake Tahoe for the purpose of vicarious calibration. This year, the Salton Sea station came on line. Salton Sea, located in southern California, gets far hotter than Lake Tahoe. Vicarious calibration results of the Salton Sea for both instruments added to the understanding of a small gain error that the Tahoe data had suggested. With the Salton Sea data, an ETM+ gain error became statistically significant. Though it causes errors as large as 1.2K at high temperatures (35C), at more usual earth temperatures (4-20C) the calibration error is within the noise of the calibration methodology (+/-0.6K). With an ETM+ calibration update, the RMSE will be +/-0.6K for all temperatures. The RIT vicarious calibration team mined the archive of the NOAA National Data Buoy Center for sites on the Great Lakes and in the Atlantic Ocean where buoy data was regularly available between 1984 and 2007 and there were radiosonde data within close proximity to allow for atmospheric correction. Four Landsat scenes were chosen and the study made use of almost 200 separate acquisitions of these scenes. The technique was first tested with Landsat-7 data, and was shown to be as reliable as the standard RIT vicarious calibration methods. The TM calibration was largely unmonitored for most if it's lifetime. The buoy results suggest a lifetime error in gain and a change in the offset after 1997. The 2007 TM calibration update accounted for much of the offset error but was only implemented for data acquired after 1999. With the additional buoy data, the calibration will be corrected for the earlier time period and the result will be a consistent calibration to within +/-0.6K for the lifetime of the TM.

Barsi, Julia A.; Markham, Brian L.; Schott, John R.; Hook, Simon J.; Raqueno, Nina G.

2009-08-01

35

Quality indicators of image-based overlay  

NASA Astrophysics Data System (ADS)

A new method for indicating the image quality of overlay measurement is proposed in this paper. Due to the constraint of the overlay control tolerance, the overlay metrology requirement has become very stringent. Current indicators such as the total measurement uncertainty (TMU) are insufficient to guarantee a good overlay measurement. This paper describes two quality indicators, the contrast index (CI) and the asymmetry index (AI). The CI is a crucial quality indicator that affects the overlay accuracy greatly. The AI, based on an imaging process with modified cross-correlation operation, shows alignment mark robustness in both the x and the y directions. For determination of the best recipe, the box-in-box overlay marks are measured to obtain the images with different conditions. The conventional TMU indicators are used first to sieve out the better choices. Then the CI and AI can help to judge whether the overlay results are reliable and can be applied to monitoring of process variations.

Chen, Yen-Liang; Huang, Jacky; Lee, Rita; Wang, Chen-Ming; Ke, Chih-Ming; Gau, Tsai-Sheng

2012-03-01

36

Water quality mapping from Landsat digital data  

Microsoft Academic Search

Landsat multispectral scanner (MSS) data, and U-2 colour and colour infrared photographs were combined with in situ data for the assessment of water quality parameters within the San Francisco Bay-Delta. The water quality parameters of interest included turbidity and suspended solids. The U-2 photography and water quality samples were obtained simultaneously and coincidently with Landsat overpass. Regression models were developed

Siamak Khorram

1981-01-01

37

Science Writers' Guide to Landsat 7  

NSDL National Science Digital Library

This guide was produced for science writers and the media and profiles several Landsat 7 research projects, and provides background and contact information. Landsat 7 is advancing several areas of Earth science, mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics. including monitoring croplands and mapping Antarctic ice streams.

1999-03-01

38

Landsat Spectral Data for Digital Soil Mapping  

Microsoft Academic Search

We propose that Landsat remotely sensed spectral data represent useful environmental covariates for digitally mapping soil distribution on the landscape, especially in arid and semiarid areas. Based on the common conceptual model that unique soils are the products of unique sets of soil-forming factors, Landsat spectral data can represent environmental covariates for vegetation (e.g., normalized dif- ference vegetation index, fractional

J. L. Boettinger; R. D. Ramsey; J. M. Bodily; N. J. Cole; S. Kienast-Brown; S. J. Nield; A. M. Saunders; A. K. Stum

39

Evaluating diffraction-based overlay  

NASA Astrophysics Data System (ADS)

We evaluate diffraction-based overlay (DBO) metrology using two test wafers. The test wafers have different film stacks designed to test the quality of DBO data under a range of film conditions. We present DBO results using traditional empirical approach (eDBO). eDBO relies on linear response of the reflectance with respect to the overlay displacement within a small range. It requires specially designed targets that consist of multiple pads with programmed shifts. It offers convenience of quick recipe setup since there is no need to establish a model. We measure five DBO targets designed with different pitches and programmed shifts. The correlations of five eDBO targets and the correlation of eDBO to image-based overlay are excellent. The targets of 800nm and 600nm pitches have better dynamic precision than targets of 400nm pitch, which agrees with simulated results on signal/noise ratio. 3? of less than 0.1nm is achieved for both wafers using the best configured targets. We further investigate the linearity assumption of eDBO algorithm. Simulation results indicate that as the pitch of DBO targets gets smaller, the nonlinearity error, i.e., the error in the overlay measurement results caused by deviation from ideal linear response, becomes bigger. We propose a nonlinearity correction (NLC) by including higher order terms in the optical response. The new algorithm with NLC improves measurement consistency for DBO targets of same pitch but different programmed shift, due to improved accuracy. The results from targets with different pitches, however, are improved marginally, indicating the presence of other error sources.

Li, Jie; Tan, Asher; Jung, JinWoo; Goelzer, Gary; Smith, Nigel; Hu, Jiangtao; Ham, Boo-Hyun; Kwak, Min-Cheol; Kim, Cheol-Hong; Nam, Suk-Woo

2012-03-01

40

Overlay metrology for double patterning processes  

NASA Astrophysics Data System (ADS)

The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double patterning processes.

Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

2009-03-01

41

Race conditions in coexisting overlay networks  

Microsoft Academic Search

Abstract— By allowing end hosts to make,independent,routing decisions at the application level, different overlay networks may unintentionally,interfere with each other. This paper,describes how,multiple,similar or dissimilar overlay,networks,could ex- perience race conditions, resulting in oscillations (in both route selection and network,load) and cascading reactions. We pinpoint the causes for synchronization,and derive an analytic formulation for the synchronization,probability,of two overlays. Our model indicates

Ram Keralapura; Chen-nee Chuah; Nina Taft; Gianluca Iannaccone

2008-01-01

42

Overlay multi-hop FEC scheme for video streaming  

Microsoft Academic Search

Overlay networks offer promising capabilities for video streaming, due to their support for application-layer processing at the overlay forwarding nodes. In this paper, we focus on the problem of providing lightweight support at selected intermediate overlay forwarding nodes to achieve increased error resilience on a single overlay path for video streaming. We propose a novel overlay multi-hop forward error correction

Yufeng Shan; Ivan V. Bajic; Shivkumar Kalyanaraman; John W. Woods

2005-01-01

43

Optimal sampling strategies for sub-100-nm overlay  

Microsoft Academic Search

Overlay control is a critical requirement of the lithographic process, and the challenge will be even greater with 0.18- micron technology, where the overlay budget is expected to shrink to 70 nm. Control of overlay is often achieved by modifying the stepping parameters to remove any correctable overlay errors. The estimated value of these parameters depends on the overlay error

Bharath Rangarajan; Michael K. Templeton; Luigi Capodieci; Ramkumar Subramanian; Alec Scranton

1998-01-01

44

LANDSAT 4 Band 6 Data Evaluation.  

National Technical Information Service (NTIS)

The objectives of this investigation are to evaluate and monitor the radiometric integrity of the LANDSAT-D Thematic Mapper (TM) thermal infrared channel (Band 6) data to develop improved radiometric preprocessing calibration techniques for removal of atm...

1984-01-01

45

Coloured Overlays and Their Benefit for Reading.  

ERIC Educational Resources Information Center

|Presents three studies where children in mainstream schools compared text on white paper with identical text covered in turn by each of 10 differently-colored plastic overlays. Shows consistency with regard to the proportion of children in mainstream education who report beneficial perceptual effects with colored overlays and who demonstrate…

Wilkins, Arnold J.; Lewis, Elizabeth; Smith, Fiona; Rowland, Elizabeth; Tweedie, Wendy

2001-01-01

46

Overlay accuracy with respect to device scaling  

NASA Astrophysics Data System (ADS)

Overlay metrology performance is usually reported as repeatability, matching between tools or optics aberrations distorting the measurement (Tool induced shift or TIS). Over the last few years, improvement of these metrics by the tool suppliers has been impressive. But, what about accuracy? Using different target types, we have already reported small differences in the mean value as well as fingerprint [1]. These differences make the correctables questionable. Which target is correct and therefore which translation, scaling etc. values should be fed back to the scanner? In this paper we investigate the sources of these differences, using several approaches. First, we measure the response of different targets to offsets programmed in a test vehicle. Second, we check the response of the same overlay targets to overlay errors programmed into the scanner. We compare overlay target designs; what is the contribution of the size of the features that make up the target? We use different overlay measurement techniques; is DBO (Diffraction Based Overlay) more accurate than IBO (Image Based Overlay)? We measure overlay on several stacks; what is the stack contribution to inaccuracy? In conclusion, we offer an explanation for the observed differences and propose a solution to reduce them.

Leray, Philippe; Laidler, David; Cheng, Shaunee

2012-03-01

47

Overlays for plain jointed concrete pavements  

NASA Astrophysics Data System (ADS)

This report describes the construction and performance of 4 concrete and 16 asphalt overlay test sections after nine years of traffic. The test sections were placed on I-85 which carries a substantial number of heavy trucks to determine what treatments and overlay type and thickness would give acceptable performance. The concrete overlay sections were placed in 1975 and consisted of 3 inch, 4 1/2 inch, and 6 inch CRC and 6 inch jointed PCC with 15 ft. and 30 ft. joint spacing. The asphalt sections were placed in 1976 with the variables being overlay thickness of 2 inches, 4 inches, and 6 inches and the placement of two geotextiles and strips of a waterproofing membrane for each overlay thickness. An Arkansas base test section was also included in the experiment.

Gulden, W.; Brown, D.

1984-09-01

48

Diffraction based overlay re-assessed  

NASA Astrophysics Data System (ADS)

In recent years, numerous authors have reported the advantages of Diffraction Based Overlay (DBO) over Image Based Overlay (IBO), mainly by comparison of metrology figures of merit such as TIS and TMU. Some have even gone as far as to say that DBO is the only viable overlay metrology technique for advanced technology nodes; 22nm and beyond. Typically the only reported drawback of DBO is the size of the required targets. This severely limits its effective use, when all critical layers of a product, including double patterned layers need to be measured, and in-die overlay measurements are required. In this paper we ask whether target size is the only limitation to the adoption of DBO for overlay characterization and control, or are there other metrics, which need to be considered. For example, overlay accuracy with respect to scanner baseline or on-product process overlay control? In this work, we critically re-assess the strengths and weaknesses of DBO for the applications of scanner baseline and on-product process layer overlay control. A comprehensive comparison is made to IBO. For on product process layer control we compare the performance on critical process layers; Gate, Contact and Metal. In particularly we focus on the response of the scanner to the corrections determined by each metrology technique for each process layer, as a measure of the accuracy. Our results show that to characterize an overlay metrology technique that is suitable for use in advanced technology nodes requires much more than just evaluating the conventional metrology metrics of TIS and TMU.

Leray, Philippe; Laidler, David; D'Havé, Koen; Cheng, Shaunee

2011-03-01

49

Landsat-4 and Landsat-5 thematic mapper band 6 historical performance and calibration  

USGS Publications Warehouse

Launched in 1982 and 1984 respectively, the Landsat-4 and -5 Thematic Mappers (TM) are the backbone of an extensive archive of moderate resolution Earth imagery. However, these sensors and their data products were not subjected to the type of intensive monitoring that has been part of the Landsat-7 system since its launch in 1999. With Landsat-4's 11 year and Landsat-5's 20+ year data record, there is a need to understand the historical behavior of the instruments in order to verify the scientific integrity of the archive and processed products. Performance indicators of the Landsat-4 and -5 thermal bands have recently been extracted from a processing system database allowing for a more complete study of thermal band characteristics and calibration than was previously possible. The database records responses to the internal calibration system, instrument temperatures and applied gains and offsets for each band for every scene processed through the National Landsat Archive Production System (NLAPS). Analysis of this database has allowed for greater understanding of the calibration and improvement in the processing system. This paper will cover the trends in the Landsat-4 and -5 thermal bands, the effect of the changes seen in the trends, and how these trends affect the use of the thermal data.

Barsi, J. A.; Chander, G.; Markham, B. L.; Higgs, N.

2005-01-01

50

A comparison of advanced overlay technologies  

NASA Astrophysics Data System (ADS)

The extension of optical lithography to 22nm and beyond by Double Patterning Technology is often challenged by CDU and overlay control. With reduced overlay measurement error budgets in the sub-nm range, relying on traditional Total Measurement Uncertainty (TMU) estimates alone is no longer sufficient. In this paper we will report scatterometry overlay measurements data from a set of twelve test wafers, using four different target designs. The TMU of these measurements is under 0.4nm, within the process control requirements for the 22nm node. Comparing the measurement differences between DBO targets (using empirical and model based analysis) and with image-based overlay data indicates the presence of systematic and random measurement errors that exceeds the TMU estimate.

Dasari, Prasad; Smith, Nigel; Goelzer, Gary; Liu, Zhuan; Li, Jie; Tan, Asher; Koh, Chin Hwee

2010-03-01

51

Diffraction based overlay metrology for ?-carbon applications  

NASA Astrophysics Data System (ADS)

Applications that require overlay measurement between layers separated by absorbing interlayer films (such as ?- carbon) pose significant challenges for sub-50nm processes. In this paper scatterometry methods are investigated as an alternative to meet these stringent overlay metrology requirements. In this article, a spectroscopic Diffraction Based Overlay (DBO) measurement technique is used where registration errors are extracted from specially designed diffraction targets. DBO measurements are performed on detailed set of wafers with varying ?-carbon (ACL) thicknesses. The correlation in overlay values between wafers with varying ACL thicknesses will be discussed. The total measurement uncertainty (TMU) requirements for these layers are discussed and the DBO TMU results from sub-50nm samples are reviewed.

Saravanan, Chandra Saru; Tan, Asher; Dasari, Prasad; Goelzer, Gary; Smith, Nigel; Woo, Seouk-Hoon; Shin, Jang Ho; Kang, Hyun Jae; Kim, Ho Chul

2008-04-01

52

Solidification of an alloy 625 weld overlay  

Microsoft Academic Search

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy\\u000a 625 weld overlay deposited on 2.25Cr - 1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy,\\u000a electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification\\u000a at ? 1216 C by a?\\/Laves eutectic-type reaction. The

J. N. DuPont

1996-01-01

53

Core level photoemission of iodine overlayers  

Microsoft Academic Search

We report the core level binding energies of chemisorbed iodine on Fe(110) and Fe(100). A decrease of 0.6 eV in the binding energies of the iodine core levels is observed with the increasing coverage of the chemisorbed iodine overlayer. This change in core level binding energies with coverage is compared with the results for iodine overlayers on other transition metal

P. A. Dowben; Y. J. Kime; D. Mueller; T. N. Rhodin

1988-01-01

54

Landsat5 TM and Landsat7 ETM+ absolute radiometric calibration using the reflectance-based method  

Microsoft Academic Search

The reflectance-based method of vicarious calibration has been used for the absolute radiometric calibration of the Landsat series of sensors since the launch of Landsat-4. The reflectance-based method relies on ground-based measurements of the surface reflectance and atmospheric conditions at a selected test site nearly coincident with the imaging of that site by the sensor of interest. The results of

Kurtis J. Thome; Dennis L. Helder; D. Aaron; James D. Dewald

2004-01-01

55

Digital image processing system for Landsat 3  

Microsoft Academic Search

A digital image processing system to support the Landsat 3 mission is discussed. NASA will provide the data reception and preprocessing facilities, while the DOE provides the production image processing system that generates film products and computer compatible tapes for users. The system was installed at the Earth Resources Observation System Data Center (EDC), and it is capable of operating

G. Harris Jr.

1979-01-01

56

Earth Observations Division Landsat Imagery Preprocessing System  

Microsoft Academic Search

The Earth Observations Division (EOD) at NASA's Lyndon B. Johnson Space Center (JSC) has recently placed into operation a new system to receive and process the Landsat imagery output of the Master Data Processor (MDP) located at the Goddard Space Flight Center (GSFC). The main purposes of the EOD System are to (1) extract areas of interest (AOI) from full

P. M. Hinson; C. H. Jeffress

1980-01-01

57

LANDSAT Image Analysis for Terrain Investigations  

Microsoft Academic Search

A study was conducted to evaluate terrain conditions in the vicinity of Daytona Beach, Florida to facilitate selection of suitable landfill sites. LANDSAT computer compatible tapes (CCT's) were analyzed using various techniques available on the General Electric IMAGE 100 system. Atmospheric haze correction was performed by normalizing the hazy images to a standard spectral reflectance which was obtained for the

B. E. Ruth; R. L. Ferguson; H. K. Brooks

1977-01-01

58

Landsat-D Investigations in Snow Hydrology.  

National Technical Information Service (NTIS)

Thematic mapper data for the southern Sierra Nevada area were registered to digital topographic data and compared to LANDSAT MSS and NOAA-7 AVHRR data of snow covered areas in order to determine the errors associated with using coarser resolution and to q...

J. Dozier

1983-01-01

59

Visualizing the uncertainty of geo-information from Landsat ETM+ imagery by fuzzy reasoning  

NASA Astrophysics Data System (ADS)

Uncertainty is one important feature of spatial information quality and attracting much more attentions recently. The visualization is an effective way to express the magnitude, pattern and propagation of the uncertainty. In this paper, the visualization method of geospatial information uncertainty in Landsat ETM+ imagery is put forward and described. Firstly, an improved fuzzy reasoning classification method is proposed, and farmland and grassland information are extracted from the ETM+ imagery respectively based on the algorithm. Then the uncertainty of the classification is analyzed, measured and visualized supported by GIS. The uncertainty can be expressed and visualized by different spatial distribution range of cropland and grassland when adjusting their membership values setting. The uncertainty threshold supplies a visual cognition for data users to know the data quality better and make full use of the data more correctly. At the same time, aiming at the overlay areas with similar membership values, other ancillary information can help to improve the classification accuracy and conquer the difficulties in distinguishing cropland from grassland in Landsat ETM+.

Wang, Ping; Huang, Fang; Liu, Xiangnan

2007-08-01

60

Solidification of an alloy 625 weld overlay  

NASA Astrophysics Data System (ADS)

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr - 1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at ? 1216 °C by a ?/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range (?170 °C) and formation of interdendritic ( ?+Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ( ?+Laves) constituent with the Scheil equation by treating the overlay system as a simple ?-Nb “binary” and using an experimentally determined k Nb value from electron microprobe data.

Dupont, J. N.

1996-11-01

61

Overlay breakdown methodology on immersion scanner  

NASA Astrophysics Data System (ADS)

In the last years a flourishing number of techniques such as High Order Control or mappers have been proposed to improve overlay control. However a sustainable improvement requires sometimes understanding the underlying causes of the overlay limiting factors in order to remove them when possible or at least to keep them under control. Root cause finding for overlay error is a tough task due the very high number of influencing parameters and the interaction of the usage conditions. This paper presents a breakdown methodology to deal with this complexity and to find the contributors of overlay error variation. We use a Partial Least Squares (PLS) algorithm to isolate the key contributors for correctable terms and a field-to-field linear regression technique to highlight the main causes of residuals. We present a study carried out on 45nm CMOS contact-gate overlay over 687 production wafers exposed in an ASML TWINSCAN XT:1700i Immersion scanner. We present the results of the correlations with the 180 process and equipment variables used for this study. For each isolated contributor we propose an explanation of the underlying physical phenomenon and solutions.

Lam, Auguste; Pasqualini, Francois; de Caunes, Jean; Gatefait, Maxime

2010-03-01

62

Robotic weld overlay coatings for erosion control  

SciTech Connect

The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB`s.

Not Available

1994-11-01

63

Robotic weld overlay coatings for erosion control  

NASA Astrophysics Data System (ADS)

The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

64

On Adding Structure to Unstructured Overlay Networks  

NASA Astrophysics Data System (ADS)

Unstructured peer-to-peer overlay networks are very resilient to churn and topology changes, while requiring little maintenance cost. Therefore, they are an infrastructure to build highly scalable large-scale services in dynamic networks. Typically, the overlay topology is defined by a peer sampling service that aims at maintaining, in each process, a random partial view of peers in the system. The resulting random unstructured topology is suboptimal when a specific performance metric is considered. On the other hand, structured approaches (for instance, a spanning tree) may optimize a given target performance metric but are highly fragile. In fact, the cost for maintaining structures with strong constraints may easily become prohibitive in highly dynamic networks. This chapter discusses different techniques that aim at combining the advantages of unstructured and structured networks. Namely we focus on two distinct approaches, one based on optimizing the overlay and another based on optimizing the gossip mechanism itself.

Leitão, João; Carvalho, Nuno A.; Pereira, José; Oliveira, Rui; Rodrigues, Luís

65

Weld overlay coatings for erosion control  

SciTech Connect

A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

Levin, B.; DuPont, J.N.; Marder, A.R.

1993-03-03

66

Landsat Data Continuity Mission, now Landsat-8: six months on-orbit  

NASA Astrophysics Data System (ADS)

The Landsat Data Continuity Mission (LDCM) with two pushbroom Earth-imaging sensors, the Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS), was launched on February 11, 2013. Its on-orbit check out period or commissioning phase lasted about 90 days. During this phase the spacecraft and its instruments were activated, operationally tested and their performance verified. In addition, during this period, the spacecraft was temporarily placed in an intermediary orbit where it drifted relative to the Landsat-7 spacecraft, providing near simultaneous imaging for about 3 days, allowing data comparison and cross calibration. After this tandem-imaging period, LDCM was raised to its final altitude and placed in the position formerly occupied by Landsat-5, i.e., 8 days out of phase with Landsat-7, with about a 10:10 AM equatorial crossing time. At the end of commissioning, the satellite was transferred to the United States Geological Survey (USGS), officially renamed Landsat-8 and declared operational. Data were made available to the public beginning May 31, 2013. The performance of the satellite and two instruments has generally been excellent as evidenced in the quality of the distributed data products.

Markham, Brian L.; Storey, James C.; Irons, James R.

2013-09-01

67

Robotic weld overlay coatings for erosion control  

SciTech Connect

Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

Levin, B.F.; Dupont, J.N.; Marder, A.R.

1993-04-18

68

Landsat5 Thematic Mapper outgassing effects  

Microsoft Academic Search

A periodic 3% to 5% variation in detector response affecting both image and internal calibrator (IC) data has been observed in bands 5 and 7 of the Landsat-5 Thematic Mapper. The source for this variation is thought to be an interference effect due to buildup of an ice-like contaminant film on a ZnSe window, covered with an antireflective coating (ARC),

Dennis L. Helder; Esad Micijevic

2004-01-01

69

Contingency plans set for Landsat 5 and 7  

NASA Astrophysics Data System (ADS)

With the Landsat 5 Earth observation satellite failing due to a rapidly degrading electronic component, the U.S. Geological Survey (USGS) is exploring ways to alleviate a data gap if both Landsat 5 and 7 fail prior to the planned launch of Landsat 8—known as the Landsat Data Continuity Mission—in 2013. USGS director Marcia McNutt told Eos that although the satellite's engineering team has “brought Landsat 5 back from death's doorstep several times over the last 27 years” during its mission—which has extended far beyond its design life—“another miracle recovery is becoming less likely.” She added that the survey is looking forward to a successful launch of Landsat 8 “and to establishing a more consistent land imaging program.”

Showstack, Randy

2012-01-01

70

An optimal discrete rate allocation for overlay video multicasting  

Microsoft Academic Search

Recently, overlay multicasting has been considered as an important approach for providing multicast services over the Internet. Due to the limited capacity and the heterogeneity of the Internet clients, using overlay multicasting for video streaming applications is a challenging task. Designing bandwidth-efficient overlay structures and optimal resource allocation are the most important techniques that can be considered to deal with

B. Akbari; Hamid R. Rabiee; Mohammed Ghanbari

2008-01-01

71

Overlay tool comparison for sub-130-nm technologies  

Microsoft Academic Search

The Overlay Metrology Advisory Group (OMAG), which includes representatives from International SEMATECH Member Companies and the National Institute of Standards and Technology, has collaborated to create a unified specification for overlay measurement tools [1]. The methodology and results of an overlay benchmarking comparison of several tools are discussed in this paper. As device technologies shrink below the sub-130nm range, a

Beth Russo; Michael Bishop; David C. Benoit; Richard M. Silver

2002-01-01

72

Curriculum overlay model for embedding digital resources  

Microsoft Academic Search

This paper describes the design and implementation of a curriculum overlay model for the representation of adaptable curriculum using educational digital library resources. We focus on representing curriculum to enable the incorporation of digital resources into curriculum and curriculum sharing and customization by educators. We defined this model as a result of longitudinal studies on educators' development and customization of

Huda J. Khan; Keith E. Maull; Tamara Sumner

2008-01-01

73

Evaluation of Concrete Overlays for Bridge Applications.  

National Technical Information Service (NTIS)

The report documents performance of 12 concrete bridge decks that were rehabilitated and/or protected with latex-modified concrete and low-slump dense concrete overlays in order to prevent future de-icing salt penetration and reinforcing steel corrosion. ...

K. Babaei

1987-01-01

74

Using Overlays to Support Context Awareness  

Microsoft Academic Search

A subset of context awareness is network context information, which requires distributed monitoring and information gathering. We propose the use of ap plication level overlays, utilising hierarchical cl ustering techniques, as the infrastructure for supporting an d providing network context information. Our proposition is supported by results from previous work in the deve lopment and deployment of an active service

Michael Fr; Glen MacLarty; Ian Wakeman

75

MOSAIC: Multiple Overlay Selection and Intelligent Composition  

Microsoft Academic Search

Today, the most effective mechanism for remedying shortcomings of the Internet, or augmenting it with new networking capabilities, is to develop and deploy a new overlay network. This leads to the problem of multi- ple networking infrastructures, each with independent advantages, and each developed in isolation. A greatly preferable solution is to have a single infrastructure un- der which new

Yun Mao; Boon Thau Loo; Zachary G Ives; Jonathan M Smith

2007-01-01

76

Scalability in Adaptive Multi-Metric Overlays  

Microsoft Academic Search

Increasing application requirements have placed heavy emphasis on building overlay networks to efficiently de- liver data to multiple receivers. A key performance chal- lenge is simultaneously achieving adaptivity to changing network conditions and scalability to large numbers of users. In addition, most current algorithms focus on a sin- gle performance metric, such as delay or bandwidth, par- ticular to individual

Adolfo Rodriguez; Dejan Kostic; Amin Vahdat

2004-01-01

77

Arigatoni: A Simple Programmable Overlay Network  

Microsoft Academic Search

We design a lightweight Overlay Network, called Ari- gatoni, that is suitable to deploy the Global Comput- ing Paradigm over the Internet. Communications over the behavioral units of the model are performed by a simple communication protocol. Basic Global Comput- ers can communicate by first registering to a brokering service and then by mutually asking and oering ser- vices, in

Didier Benza; Michel Cosnard; Luigi Liquori; Marc Vesin

2006-01-01

78

The Overlay Network Content Distribution Problem  

Microsoft Academic Search

Due to the lack of deployment of a network-layer multi- cast service, many overlay multicast protocols have been designed and deployed across the Internet to support con- tent distribution. To our knowledge, however, none have pro- vided a rigorous analysis of the problem or the effectiveness of their proposed solutions. Here, we set aside the engineer- ing challenges of protocol

Chip Killian; Michael Vrable; Alex C. Snoeren; Amin Vahdat; Joseph Pasquale

2005-01-01

79

Investigation of Iron Aluminide Weld Overlays  

Microsoft Academic Search

Conventional fossil fired boilers have been retrofitted with low NO(sub)x burners in order for the power plants to comply with new clean air regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion typically has been enhanced resulting in premature tube failure. To protect the existing panels from accelerated attack, weld overlay coatings are typically being applied.

S. W. Banovic; J. B. DuPont; B. F. Levin; A. R. Marder

1999-01-01

80

Chainsaw: Eliminating Trees from Overlay Multicast  

Microsoft Academic Search

In this paper, we present Chainsaw, a p2p overlay mul- ticast system that completely eliminates trees. Peers are notified of new packets by their neighbors and must ex- plicitly request a packet from a neighbor in order to re- ceive it. This way, duplicate data can be eliminated and a peer can ensure it receives all packets. We show with

Vinay S. Pai; Kapil Kumar; Karthik Tamilmani; Vinay Sambamurthy; Alexander E. Mohr

2005-01-01

81

iOverlay: A Lightweight Middleware Infrastructure for Overlay Application Implementations  

Microsoft Academic Search

The very nature of implementing and evaluating fully distributed algorithms or protocols in application-layer overlay networks involves certain programming tasks that are at best mundane and tedious -- and at worst challenging -- even at the application level. In this paper, we present iOverlay<\\/I>, a lightweight and high-performance middleware infrastructure that addresses these problems in a novel way by providing

Baochun Li; Jiang Guo; Mea Wang

2004-01-01

82

Supersparse overlay sampling plans: an evaluation of methods and algorithms for optimizing overlay quality control and metrology tool throughput  

Microsoft Academic Search

Traditionally, overlay metrology has ben primarily used for quality control of developed wafers. The secondary roles of overlay metrology, stepper modeling and feedback control, have become more prominent in recent years. In particular, the design of overlay sampling plans is usually strongly influenced by the requirements imposed by stepper modeling. Previous research has shown that intrafield sampling plans must be

Joseph C. Pellegrini; Ziad R. Hatab; Jeffrey M. Bush; Thomas R. Glass

1999-01-01

83

Monitoring of rice field by using Landsat-5 TM and Landsat-7 ETM+ data  

NASA Astrophysics Data System (ADS)

The relation between the typical vegetation indices (NDVI, EVI, etc.) computed from the time series data of Landsat-5 TM and Landsat-7 ETM+ and the physical parameters (plant height of a rice, the spread of blade, LAI, vegetation coverage, etc.) concerned with a rice growth obtained by the field survey w s investigated. In this analysis, in order to use Landsat-5 TM (Thematic Mapper) dataa launched in 1984 together with Landsat-7 ETM+ (Enhanced Thematic Mapper Plus) data launched in 1999, the digital counts were converted into the spectral radiances by the calibration parameters recorded on satellite data, and the vegetation indices were computed using those values. On the other hand, the proportion ratio of the components (blade of a rice, ear of a rice, background water, background soil) of the rice field that exists in a fixed acreage was computed by the pictures of the rice field taken by a digital camera, and t e spectral reflectance of each object within the rice field collected by a portableh spectrometer (MSR-7000) was mixed using this proportion. Moreover, the periodical changes of the vegetation indices of the rice field from the planting of rice to the harvest were simulated based on the mixture model. The result of this study indicates that the periodical changes of vegetation indices of the rice field computed from satellite data are primarily correlated to the changes of

Oguro, Y.; Suga, Y.; Takeuchi, S.; Ogawa, H.; Tsuchiya, K.

84

Landsat: The Backbone for Mapping and Monitoring Global Ecological Trends  

NASA Astrophysics Data System (ADS)

Long-term ecological monitoring requires consistent observation of key variables, long-term measurement continuity, and open and affordable access to measurements. The Landsat series of Earth observation missions uniquely meet those criteria, and Landsat's 30m-observation scale permits the detection and differentiation of natural versus human-caused land change. Landsat is the longest and most comprehensive record of the state of the global land surface in existence. No other high-resolution satellite program is either capable or committed to the systematic monitoring of global scale human and natural land change. Beginning with Landsat 1 in 1972, six Landsat missions have continuously recorded images of the Earth. As we near the fortieth anniversary of Landsat, we now have an archive of millions of repetitive images of the Earth with multispectral properties suited to assessing both biotic and abiotic conditions and at a scale appropriate for resource management. The U.S. Geological Survey's (USGS) Earth Resources Observations Systems (EROS) Landsat archive contains nearly three million scenes and all are available to users at no cost. Furthermore, the entire Landsat record, Landsats 1-7, is now calibrated to a common radiometric standard and the majority of the data are orthorectified - enabling immediate assessment of long-term ecological conditions and land change. Landsats 5 and 7 continue to collect imagery and together they provide the potential to cover a significant portion of the Earth's land surfaces every eight days. Both of these missions now use a long-term acquisition plan designed to improve the collection of seasonal global coverage. Furthermore, recent agreements with international Landsat receiving stations are bringing previously inaccessible contemporary Landsat 5 data into the EROS archive. The amount of global coverage being acquired annually is the highest level in the history of the Landsat program. The EROS global historical archive is rapidly expanding because of the addition of 1972-present Landsat holdings from ground stations worldwide. More than three million Landsat scenes not currently found in the EROS archive exist in archives around the world and many of these data are at risk due to aging storage media and inadequate preservation practices. The repatriation of these data into the EROS archive will potentially double the number of no-cost Landsat scenes available to users. The uncertainty of future Landsat missions has challenged operational monitoring of ecological systems. However, that may be changing. The Landsat Data Continuity Mission (LDCM) being developed by NASA and the USGS is slated for a December 2012 launch. LDCM (which will be renamed Landsat 8 following launch) will use new imaging technology to provide improved multispectral measurements, and offers additional spectral bands and increased daily imaging capacity. While missions beyond LDCM are uncertain, the President's Fiscal Year 2012 budget requests funds for the planning and development of Landsats 9 and 10, and includes language that will make Landsat an operational program - ending the decades of uncertainty.

Loveland, T. R.

2011-12-01

85

The Landsat Image Mosaic of Antarctica (LIMA)  

NSDL National Science Digital Library

By studying Antarctica via satellite and through ground-truthing research, we can learn where the ice is melting and why. The Landsat Image Mosaic of Antarctica (LIMA), a new and cutting-edge way for scientists, researchers, educators, students, and the public to look at Antarctica, supports this research and allows for unprecedented views of our coldest and driest landmass. This article discusses LIMA, presents two LIMA-based classroom activities, and calls for science teachers to create additional related activities for classrooms around the world.

Campbell, Brian; Bindschadler, Robert

2009-01-01

86

Landsat Data Continuity Mission Operational Land Imager: Radiometric Performance.  

National Technical Information Service (NTIS)

The Operational Land Imager (OLI) is one of two instruments to fly on the Landsat Data Continuity Mission (LDCM), which is scheduled to launch in December 2012 to become the 8th in the series of Landsat satellites. The OLI images in the solar reflective p...

B. Markham J. Pedelty P. Dabney

2011-01-01

87

Snow Scene of the Lake Erie Area from Landsat.  

ERIC Educational Resources Information Center

|A snow-covered landscape as viewed from Landsat offers some intriguing possibilities for interpretation of various earth features that are difficult to discern on imagery taken at other times of the year. This Landsat image can be analyzed and studied by college- level geography students. (AM)|

Harnapp, Vern

1982-01-01

88

Radiometric comparison of the LANDSAT5 TM and MSS sensors  

Microsoft Academic Search

This paper analyses the radiometric accuracy of LANDSAT-5 Thematic Mapper (TM) data and of LANDSAT-5 Multispectral Scanner (MSS) data, using concurrent TM and MSS images recorded simultaneously over the city of Montreal, Quebec, Canada. The data sets were obtained from the Canada Centre for Remote Sensing (CCRS), and have been preprocessed for geometric correction, and for radiometric 23calibration utilizing the

ALAIN ROYER; RICHARD BROCHU; JENNIFER M. MURPHY; PHILIPPE M. TEILLET

1987-01-01

89

Twenty-Five Years of Landsat Thermal Band Calibration.  

National Technical Information Service (NTIS)

Landsat-7 Enhanced Thematic Mapper+ (ETM+), launched in April 1999, and Landsat-5 Thematic Mapper (TM), launched in 1984, both have a single thermal band. Both instruments thermal band calibrations have been updated previously: ETM+ in 2001 for a pre-laun...

B. L. Markham J. A. Barsi J. R. Schoff N. G. Raqueno S. J. Hook

2010-01-01

90

Analyzing remote sensing data in R: the landsat package  

Technology Transfer Automated Retrieval System (TEKTRAN)

Research and development on atmospheric and topographic correction methods for multispectral satellite data such as Landsat images has far outpaced the availability of those methods in Geographic Information Systems software. As Landsat and other data become more widely available, demand for these i...

91

Using overlays to improve network security  

NASA Astrophysics Data System (ADS)

As we increase our dependency upon networked communication, the incentive to compromise and degrade network performance increases for those who wish to disrupt the flow of information. Attacks that lead to such compromise and degradation can come in a variety of forms, including distributed denial of service (DDoS) attacks, cutting wires, jamming transmissions, and monitoring/eavesdropping. Users can protect themselves from monitoring by applying cryptographic techniques, and the recent work has explored developing networks that react to DDoS attacks by locating the source(s) of the attack. However, there has been little work that addresses preventing the other kinds of attacks as opposed to reacting to them. Here, we discuss how network overlays can be used to complicate the job of an attacker that wishes to prevent communication. To amplify our point, we focus briefly on a study of preventing DDoS attacks by using overlays.

Keromytis, Angelos D.; Misra, Vishal; Rubenstein, Daniel

2002-07-01

92

Application of layout overlay for failure analysis  

Microsoft Academic Search

New layout overlay techniques have been developed based on standard image correlation techniques to support failure analysis in modern microelectronic devices, which are critical to analyze because they are realized in new technologies using sub-?m design rules, chemical mechanical polishing techniques CMP and auto-routing design techniques. As the new techniques are realized as an extension of a standard CAD-navigation software

C. Burmer; S. Görlich; S. Pauthner

1998-01-01

93

Landsat continuity: Issues and opportunities for land cover monitoring  

USGS Publications Warehouse

Initiated in 1972, the Landsat program has provided a continuous record of earth observation for 35??years. The assemblage of Landsat spatial, spectral, and temporal resolutions, over a reasonably sized image extent, results in imagery that can be processed to represent land cover over large areas with an amount of spatial detail that is absolutely unique and indispensable for monitoring, management, and scientific activities. Recent technical problems with the two existing Landsat satellites, and delays in the development and launch of a successor, increase the likelihood that a gap in Landsat continuity may occur. In this communication, we identify the key features of the Landsat program that have resulted in the extensive use of Landsat data for large area land cover mapping and monitoring. We then augment this list of key features by examining the data needs of existing large area land cover monitoring programs. Subsequently, we use this list as a basis for reviewing the current constellation of earth observation satellites to identify potential alternative data sources for large area land cover applications. Notions of a virtual constellation of satellites to meet large area land cover mapping and monitoring needs are also presented. Finally, research priorities that would facilitate the integration of these alternative data sources into existing large area land cover monitoring programs are identified. Continuity of the Landsat program and the measurements provided are critical for scientific, environmental, economic, and social purposes. It is difficult to overstate the importance of Landsat; there are no other systems in orbit, or planned for launch in the short-term, that can duplicate or approach replication, of the measurements and information conferred by Landsat. While technical and political options are being pursued, there is no satellite image data stream poised to enter the National Satellite Land Remote Sensing Data Archive should system failures occur to Landsat-5 and -7. Crown Copyright ?? 2007.

Wulder, M. A.; White, J. C.; Goward, S. N.; Masek, J. G.; Irons, J. R.; Herold, M.; Cohen, W. B.; Loveland, T. R.; Woodcock, C. E.

2008-01-01

94

Achieving optimum diffraction based overlay performance  

NASA Astrophysics Data System (ADS)

Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

2010-03-01

95

Media delivery and media service overlays  

NASA Astrophysics Data System (ADS)

Multimedia communication and streaming media services will become mainstream network infrastructure applications in the coming decade. However, there are many challenges that must be overcome. These challenges include the Internet"s limited ability to handle real-time, low-latency media streams, the need for media security, and an uncertainty of the killer app. The nature of these challenges lends itself to enabling technology innovations in the media delivery and media processing space. Specifically, we envision an overlay infrastructure that supports networked media services that couple media delivery with in-network media processing. The media overlay should be programmable to allow rapid deployment of new applications and services and manageable so as to support the evolving requirements of the resulting usage models. Furthermore, the media overlay should allow for the delivery of protected media content for applications that have security requirements. A properly architected infrastructure can enable real-time multimedia communication and streaming media services in light of the inherent challenges.

Wee, Susie

2005-03-01

96

Overlay tool comparison for sub-130-nm technologies  

NASA Astrophysics Data System (ADS)

The Overlay Metrology Advisory Group (OMAG), which includes representatives from International SEMATECH Member Companies and the National Institute of Standards and Technology, has collaborated to create a unified specification for overlay measurement tools [1]. The methodology and results of an overlay benchmarking comparison of several tools are discussed in this paper. As device technologies shrink below the sub-130nm range, a critical need arises to develop more precise tools to measure overlay. Overlay metrology capability needs to be available for detecting and controlling total device overlay regardless of the source of error. The misregistration measurement uncertainty introduced by the overlay tool can be compared for several systems. A benchmarking study is currently underway and focuses on the existing technique of optical measurement of centerline offsets in different target designs. The critical parameters that the study analyzes include precision, accuracy, throughput, through focus measurements, and recipe portability. Imaging issues such as low contrast targets, across wafer thickness variation, CMP effects, and grainy metal targets can contribute greatly to overlay errors. Several process stacks were designed to incorporate some of these imaging issues and test the limitations of the overlay tools. The same set of wafers and test locations were measured at each supplier site and the results were analyzed. This paper focuses on the methodology used for overlay benchmarking and examples of the results generated with respect to the parameters tested.

Russo, Beth; Bishop, Michael; Benoit, David C.; Silver, Richard M.

2002-07-01

97

Advanced process control applied to metal layer overlay process  

NASA Astrophysics Data System (ADS)

Overlay control of printed layers onto processed metal levels highly depends on the process influences to the alignment and overlay measurement targets. This study characterizes the systematic influence to both alignment and overlay metrology based on AlCu deposition and W CMP. The systematic influence of AlCu deposition to alignment and overlay targets are explored in theory and then verified experimentally. Both theory and experimental results are then validated empirically as "non-zero" overlay control is applied to high volume production to increase wafer edge yield. The influence of W CMP on lot-to-lot overlay performance is also characterized and accounted for to further improve metal one overlay performance. The emphasis of this paper will be model-based Advanced Process Control (APC). Methods used to characterize process influence on overlay for a back-end metal process will be discussed. We will then describe how predictive overlay was modeled in terms of AlCu deposition target life, W CMP endpoint as well as normal control context such as exposure tool and part id. The challenge of implementing APC for increased context partitioning is discussed and the need for a model-based approach is stressed. The methodology used for lot disposition in the case of "non-zero" targeted overlay is also explained.

Gould, Christopher J.; Cui, Yuanting; Louks, Sean

2004-04-01

98

Experimental AC (Asphalt Concrete) overlays of PCC pavement  

NASA Astrophysics Data System (ADS)

A series of experimental asphalt concrete (AC) overlays was constructed over an existing distressed portland cement concrete pavement on Interstate 80 near Boca, California. The experimental overlays included rubberized dense-graded AC, rubberized open-graded AC, a rubber flush coat interlayer, dense-graded AC with short polyester fibers and Bituthene interlayer strips. The report presents a description and discussion of AC mix batching, construction observations, laboratory testing, overlay covering, and initial performance evaluation.

Smith, R. D.

1983-11-01

99

T-Man: Gossip-based fast overlay topology construction  

Microsoft Academic Search

Large-scale overlay networks have become crucial ingredients of fully-decentralized applications and peer-to-peer systems. Depending on the task at hand, overlay networks are organized into different topologies, such as rings, trees, semantic and geographic proximity networks. We argue that the central role overlay networks play in decentralized application development requires a more systematic study and effort towards understanding the possibilities and

Márk Jelasity; Alberto Montresor; Özalp Babaoglu

2009-01-01

100

Field application and performance of concrete overlay for pavement rehabilitation  

Microsoft Academic Search

A test section of concrete overlay was constructed and monitored for one year to evaluate the feasibility as a rehabilitation\\u000a alternative for deteriorated concrete pavement in Korea. The test section of 2-lane 290m long on 88 Highway near Jirisan I\\/C\\u000a included 25cm unbonded and 6cm and 10cm bonded concrete overlays. High early-strength slag cement was used in the overlay\\u000a concrete

Kyong-ku Yun; Young-chan Suh

1999-01-01

101

Pushback for Overlay Networks: Protecting Against Malicious Insiders  

Microsoft Academic Search

Peer-to-Peer (P2P) overlay networks are a flexible way of creating decentralized services. Although resilient to external Denial of Service attacks, overlay networks can be rendered inoperable by simple flooding attacks generated from insider nodes. In this paper, we study detection and containment mechanisms against insider Denial of Service (DoS) attacks for overlay networks. To counter such attacks, we introduce novel

Angelos Stavrou; Michael E. Locasto; Angelos D. Keromytis

2008-01-01

102

Turning Heterogeneity into an Advantage in Overlay Routing  

Microsoft Academic Search

Distributed hash table (DHT)-based overlay net- works, represented by Pastry, CAN, and Chord, offer an administration-free and fault-tolerant application-level overlay network. While elegant from a theoretical perspective, these systems have some disadvantages. First, they rely on application- level routing, which may be inefficient with respect to network delays and bandwidth consumption. Second, they typically con- struct a homogeneously structured overlay

Zhichen Xu; Mallik Mahalingam; Magnus Karlsson

2003-01-01

103

Experimental verification of analytically determined weld overlay residual stress distribution  

SciTech Connect

The main objective of this test program was to compare the experimentally determined residual stress distribution through the pipe wall resulting from weld overlay repair to that calculated by an analytical model. Two different weld overlay thicknesses and a last-pass heat sink weld were applied to pipe specimens using procedures that were qualified and in use for plant repairs in the United States. Conceptual description of the weld overlay repair, a discussion of specimen preparation, and results are presented.

Kulat, S.D.; Pitcairn, D.R.; Sobon, L.J.

1985-01-01

104

Policy-Based Resource Sharing in Streaming Overlay Networks  

Microsoft Academic Search

In this chapter, we discuss peer-to-peer media streaming overlay network architectures and introduce a policy-based architecture for streaming live media from media sources to end-users over independently owned and operated networks. This architecture (mSON) efficiently supports multiple simultaneous media streams, with different sources and user populations, through shared overlay resources. The overlay network infrastructure takes into account the existence of

K. Selcuk Candan; Yusuf Akca; Wen-Syan Lit

105

Scanner grid recipe creation improvement for tighter overlay specifications  

NASA Astrophysics Data System (ADS)

Overlay specifications are tightening with each lithography technology node. As a result, there is a need to improve overlay control methodologies to make them more robust and less time- or effort-consuming, but without any compromise in quality. Two concepts aimed at improving the creation of scanner grid recipes in order to meet evertightening overlay specifications are proposed in this article. Simulations will prove that these concepts can achieve both goals, namely improving overlay control performance and reducing the time and effort required to do so. While more studies are needed to fine-tune the parameters to employ, the trends presented in this paper clearly show the benefits.

Cotte, Eric; Kathiresan, Hariharasudhan; Ruhm, Matthias; Schulz, Bernd; Schulze, Uwe

2013-10-01

106

Earth As Art 3: A Landsat Perspective  

NSDL National Science Digital Library

Circling high above the Earth, Landsat satellites have collected digital image photographs of the planet's continents and coastal areas. The Library of Congress has collected a number of these remarkable images (with the assistance of the United States Geological Survey) and visitors to this site can use the interactive features to zoom in and out on each image. The images have interesting titles, like "Empty Quarter", "Algerian Abstract", and "Ghostly Grease Ice". Each image can be sent as a postcard, and a brief paragraph or two describes the scene far below on the Earth's surface. Finally, visitor can also click on the "Learn More" tab to learn about additional web-based and print materials.

107

LANDSAT ESTUARINE WATER QUALITY ASSESSMENT OF SILVICULTURE AND DREDGING ACTIVITIES  

EPA Science Inventory

This report describes the application of Landsat multispectral scanning to estuarine water quality, with specific reference to dredging and silviculture practices. Water quality data collected biweekly since 1972 in the Apalachicola, Bay, Florida, by Florida State University, and...

108

Landsat's Role in Ecological Applications of Remote Sensing  

NSDL National Science Digital Library

This peer-reviewed resource from Bioscience is about the unique role of Landsat in remote sensing. Remote sensing, geographic information systems, and modeling have combined to produce a virtual explosion of growth in ecological investigations and applications that are explicitly spatial and temporal. Of all remotely sensed data, those acquired by Landsat sensors have played the most pivotal role in spatial and temporal scaling. Modern terrestrial ecology relies on remote sensing for modeling biogeochemical cycles and for characterizing land cover, vegetation biophysical attributes, forest structure, and fragmentation in relation to biodiversity. Given the more than 30-year record of Landsat data, mapping land and vegetation cover change and using the derived surfaces in ecological models is becoming commonplace. In this article, we summarize this large body of work, highlighting the unique role of Landsat.

WARREN B. COHEN and SAMUEL N. GOWARD (;)

2004-06-01

109

First Images from Landsat 7: Sailing Down the Missouri River  

NSDL National Science Digital Library

First Images from Landsat 7, South Dakota and the Missouri River. In this animation the viewer is flown down the Missouri river and delivered to Yankton, South Dakota, from an image taken April 22, 1998.

Snodgrass, Stuart; Williams, Darrel

1999-04-22

110

Analysis of the Tanana River Basin Using Landsat Data.  

National Technical Information Service (NTIS)

Digital image classification techniques were used to classify land cover/resource information in the Tanana River Basin of Alaska. Portions of four scenes of LANDSAT digital data were analyzed using computer systems at Ames Research Center in an unsupervi...

L. A. Morrissey V. G. Ambrosia C. Carson-henry

1981-01-01

111

Extrapolation of Spectral Signatures Illustrates LANDSATs' Potential to Detect Wetlands.  

National Technical Information Service (NTIS)

Spectral signatures of a wetland area were determined using LANDSAT MSS data, hydromorphic soil information, and a pixel extraction technique. Investigations indicate that wetlands could be identified and that the same wetland signatures could be extrapol...

A. Howman

1988-01-01

112

Cloud characterization and clear-sky correction from Landsat7  

Microsoft Academic Search

Landsat, with its wide swath and high resolution, fills an important mesoscale gap between atmospheric variations seen on a few kilometer scale by local surface instrumentation and the global view of coarser resolution satellites such as MODIS. In this important scale range, Landsat reveals radiative effects on the few hundred-meter scale of common photon mean-free-paths, typical of scattering in clouds

R. F Cahalan; L Oreopoulos; G Wen; A Marshak; S.-C Tsay; T DeFelice

2001-01-01

113

Avaliacao de Areas Indigenas Utilizando-Se Dados TM/Landsat (Evaluation of Indigenous Areas Utilizing TM/LANDSAT Data).  

National Technical Information Service (NTIS)

The objective is to provide environmental information about indigenous areas. The study area is located in Boa Vista, Bonfim e Alto Alegre in Roraima Territory, Brazil. Based on visual analysis of TM/LANDSAT data, several classes of vegetation associated ...

P. H. Filho K. Defaria

1990-01-01

114

Diffraction-based overlay metrology for double patterning technologies  

NASA Astrophysics Data System (ADS)

The extension of optical lithography to 32nm and beyond is made possible by Double Patterning Techniques (DPT) at critical levels of the process flow. The ease of DPT implementation is hindered by increased significance of critical dimension uniformity and overlay errors. Diffraction-based overlay (DBO) has shown to be an effective metrology solution for accurate determination of the overlay errors associated with double patterning [1, 2] processes. In this paper we will report its use in litho-freeze-litho-etch (LFLE) and spacer double patterning technology (SDPT), which are pitch splitting solutions that reduce the significance of overlay errors. Since the control of overlay between various mask/level combinations is critical for fabrication, precise and accurate assessment of errors by advanced metrology techniques such as spectroscopic diffraction based overlay (DBO) and traditional image-based overlay (IBO) using advanced target designs will be reported. A comparison between DBO, IBO and CD-SEM measurements will be reported. . A discussion of TMU requirements for 32nm technology and TMU performance data of LFLE and SDPT targets by different overlay approaches will be presented.

Dasari, Prasad; Korlahalli, Rahul; Li, Jie; Smith, Nigel; Kritsun, Oleg; Volkman, Cathy

2009-03-01

115

PlanetSim: A New Overlay Network Simulation Framework  

Microsoft Academic Search

Current research in peer to peer systems is lacking appro- priate environments for simulation and experimentation of large scale overlay services. This has led to a plethora of custom made simulators that waste development resources and hinder fair comparisons between different approaches. In this paper we present a new simulation \\/ ex- perimentation framework for large scale overlay services with

Pedro García López; Carles Pairot; Rubén Mondéjar; Jordi Pujol Ahulló; Helio Tejedor; Robert Rallo

2004-01-01

116

Considering Priority in Overlay Multicast Protocols Under Heterogeneous Environments  

Microsoft Academic Search

Hosts participating in overlay multicast applications have a wide range of heterogeneity in bandwidth and participa- tion characteristics. In this paper, we highlight and show the need to systematically consider prioritization as a key criterion in the design of protocols for overlay multicast. We identify trade-offs in the design of prioritization heuristics in two important contexts. The first part of

Michael Bishop; Sanjay G. Rao; Kunwadee Sripanidkulchai

2006-01-01

117

Overlay budget considerations for an all-scanner fab  

Microsoft Academic Search

According to the SIA roadmap an overlay of 65nm is necessary for state of the art 0.18micrometers processes. To meet such tight requirements it is necessary to know the magnitude of all contributions, to understand possible interactions and to try to drive every individual overlay component to its ultimate lower limit. In this experimental study we evaluate the impact of

Rolf Seltmann; Wolfgang Demmerle; Marc Staples; Anna Maria Minvielle; Bernd Schulz; Sven Muehle

2000-01-01

118

Topology-aware overlay networks for group communication  

Microsoft Academic Search

We propose an application level multicast approach, Topology Aware Grouping (TAG), which exploits underlying network topology information to build efficient overlay networks among multicast group members. TAG uses information about path overlap among members to construct a tree that reduces the overlay relative delay penalty, and reduces the number of duplicate copies of a packet on the same link. We

Minseok Kwon; Sonia Fahmy

2002-01-01

119

Performance of Thin Bonded Concrete Overlays in Illinois.  

National Technical Information Service (NTIS)

In recent years, two bonded conctrete overlays (BCO) have been constructed in Illinois. The first was constructed in 1994 - 1995 on a section of Interstate-80 (I-80), east of Moline, Illinois. The second bonded concrete overlay was placed in 1996 on a sec...

T. H. Volle

2000-01-01

120

Routing on Overlay Graphs in Mobile Ad Hoc Networks  

Microsoft Academic Search

Geometric routing using source-destination locations has been widely suggested as a scalable alternative to conventional routing approaches in mobile ad hoc networks. Recently, there has been considerable attention on face routing in planar graphs constructed from overlay graphs in wireless networks. Given a plane tiled into an infinite mesh of polygons, an overlay graph is defined as one in which

Sumesh J. Philip; Joy Ghosh; Hung Q. Ngo; Chunming Qiao

2006-01-01

121

A map overlay error model based on boundary geometry  

USGS Publications Warehouse

An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error-boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time. ?? 2005 The Ohio State University.

Gaeuman, D.; Symanzik, J.; Schmidt, J. C.

2005-01-01

122

Eclipse Attacks on Overlay Networks: Threats and Defenses  

Microsoft Academic Search

Overlay networks are widely used to deploy func- tionality at edge nodes without changing network routers. Each node in an overlay network maintains connections with a number of peers, forming a graph upon which a distributed application or service is implemented. In an \\

Atul Singh; Tsuen-wan Ngan; Peter Druschel; Dan S. Wallach

2006-01-01

123

Bullet: high bandwidth data dissemination using an overlay mesh  

Microsoft Academic Search

In recent years, overlay networks have become an effective alternative to IP multicast for efficient point to multipoint communication across the Internet. Typically, nodes self-organize with the goal of forming an efficient overlay tree, one that meets performance targets without placing undue burden on the underlying network. In this paper, we target high-bandwidth data distribution from a single source to

Dejan Kostic; Adolfo Rodriguez; Jeannie R. Albrecht; Amin Vahdat

2003-01-01

124

Landsat data conversion cut from budget  

NASA Astrophysics Data System (ADS)

The conversion of a set of early Landsat data from wide band videotape to digitized, computer-compatible form is slated to end prematurely when this fiscal year ends on September 30, 1986. The National Aeronautics and Space Administration (NASA) is shutting down the project to save money because of the Gramm-Rudman-Hollings deficit reduction act (Eos, January 28, 1986, p. 41) and in view of the strain on NASA's budget caused by the loss of the space shuttle Challenger, according to Joseph Bishop, program manager for data processing in NASA's Office of Space Tracking and Data Systems. Moreover, the only equipment that can be used to read the wide band videotape data and convert it to computer-compatible tape (CCT) has become obsolete, and the tapes themselves are deteriorating, so it seems unlikely that this project could be renewed in the future, according to Allen H. Watkins, chief of the Earth Resources Observation System (EROS) Data Center of the U.S. Geological Survey in Sioux Falls, S. Dak.

Katzoff, Judith A.

125

Weld overlay cladding with iron aluminides  

SciTech Connect

The hot and cold cracking tendencies of some early iron aluminide alloy compositions limited their use to applications where good weldability was not required. Considerable progress has been made toward improving this situation. Using hot crack testing techniques developed at ORNL and a systematic study of alloy compositional effects, we have established a range of compositions within which hot cracking resistance is very good, essentially equivalent to stainless steel. Cold cracking, however, remains an issue, and extensive efforts are continuing to optimize composition and welding parameters, especially preheat and postweld heat treatment, to minimize its occurrence. In terms of filler metal and process development, we have progressed from sheared strip through aspiration cast rod and shielded metal arc electrodes to the point where we can now produce composite wire with a steel sheath and aluminum core in coil form, which permits the use of both the gas tungsten arc and gas metal arc processes. This is a significant advancement in that the gas metal arc process lends itself well to automated welding, and is the process of choice for commercial weld overlay applications. Using the newly developed filler metals, we have prepared clad specimens for testing in a variety of environments both in-house and outside ORNL, including laboratory and commercial organizations. As a means of assessing the field performance of this new type of material, we have modified several non-pressure boundary boiler components, including fuel nozzles and port shrouds, by introducing areas of weld overlay in strategic locations, and have placed these components in service in operating boilers for a side-by-side comparison with conventional corrosion-resistant materials.

Goodwin, G.M.

1996-11-01

126

Advanced diffraction-based overlay for double patterning  

NASA Astrophysics Data System (ADS)

Diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges as the dimensions of integrated circuit continue to shrink. Several studies published recently have demonstrated that the performance of DBO technologies has the potential to meet the overlay metrology budget for 22nm technology node. However, several hurdles must be cleared before DBO can be used in production. One of the major hurdles is that most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. A more advanced spectroscopic ellipsometry (SE) technology-Mueller Matrix SE (MM-SE) is developed to address the challenge. We use a double patterning sample to demonstrate the potential of MM-SE as a DBO candidate. Sample matrix (the matrix that describes the effects of the sample on the incident optical beam) obtained from MM-SE contains up to 16 elements. We show that the Mueller elements from the off-diagonal 2x2 blocks respond to overlay linearly and are zero when overlay errors are absent. This superior property enables empirical DBO (eDBO) using two pads per direction. Furthermore, the rich information in Mueller matrix and its direct response to overlay make it feasible to extract overlay errors from only one pad per direction using modeling approach (mDBO). We here present the Mueller overlay results using both eDBO and mDBO and compare the results with image-based overlay (IBO) and CD-SEM results. We also report the tool induced shifts (TIS) and dynamic repeatability.

Li, Jie; Liu, Yongdong; Dasari, Prasad; Hu, Jiangtao; Smith, Nigel; Kritsun, Oleg; Volkman, Catherine

2010-03-01

127

Data Specifications for the Landsat Data Continuity Mission  

USGS Publications Warehouse

The National Aeronautics and Space Administration (NASA) plans to procure data from a privately-owned and commercially-operated remote sensing system for the next Landsat mission, the Landsat Data Continuity Mission (LDCM). Data requirements are documented in an LDCM Data Specification. The specifications require delivery of data covering 250 Landsat scenes on a daily basis. The data are to be acquired in a manner that affords seasonal coverage of the global land mass. Data are required for the heritage reflective Thematic Mapper (TM) spectral bands plus two new bands, a blue band for coastal zone observations and a short wave infrared band for cirrus cloud detection. The specifications do not require thermal data, representing a departure from the TM heritage. The specification also requires data providing a 30 m ground sample distance for each of the spectral bands with the exception of the new cirrus cloud band at 120 m. An absolute uncertainty of 5 percent or less is required for radiometrically corrected LDCM data and the commercial operator is required to deliver data that can be registered to a cartographic projection with an uncertainty of 65 m or less. Procuring data from a commercial operator represents a new approach for the 30-year-old Landsat Program. The LDCM Data Specification will ensure that the procured data provides continuity of the Landsat data stream and advances the mission.

Irons, J. R.; Speciale, N. J.; Douglas, McCuistion, J.; Masek, J. G.; Markham, B. L.; Storey, J. C.; Lencioni, D. E.; Ryan, R. E.

2003-01-01

128

Deforestation Planning for Cattle Grazing in Amazon Basin Using LANDSAT Data.  

National Technical Information Service (NTIS)

The author has identified the following significant results. This research did not show the total potential of the LANDSAT system, but tried to open up new research aspects for the utilization of LANDSAT data in natural resource control. Results obtained ...

N. de Jesus Parada A. P. dos Santos E. M. L. de Morais Novo

1978-01-01

129

Landsat Witnesses the Destruction of Mesopotamian Ecosystem  

NSDL National Science Digital Library

In one of the greatest ecological disasters of our time, the ancient marshlands of Mesopotamia are systematically being converted to dry salt flats as a result of human mismanagement of the regions water resources.Landsat satellite imagery reveals that in the last 10 years, wetlands that once covered as much as 20,000 square km in parts of Iraq and Iran have been reduced to a small fraction of their original size. The authors of a new report released by the United Nations Environment Programmes (UNEP) at the 11th Stockholm Water Symposium on August 13, 2001, warn that the marshlands could completely disappear within the next 3-5 years unless dramatic steps are taken immediately to reverse the damage being done. The UNEP Executive Director described the wetlands condition as a major environmental catastrophe that will be remembered as one of humanitys worst engineered disasters. He noted that the tragic loss of this rare wetland has occurred in approximately the same period since world leaders pledged to safeguard the environment at the United Nations Conference on Environment and Development (the Earth Summit) held in Rio de Janeiro in 1992. Regarded by historians as one of the cradles of civilization, the Mesopotamian Fertile Crescent has supported Marsh Arab society for millennia. But through the damming and siphoning off of waters from the Tigris and Euphrates Rivers, the countries of Iran, Iraq, Turkey, and Syria have decimated the ecosystem and, with it, a culture rooted in the dawn of human history (dating back to ancient Sumeria about 5,000 years ago).

Perkins, Lori; Partow, Hassan

2001-08-02

130

Automated method for overlay sample plan optimization based on spatial variation modeling  

Microsoft Academic Search

In this paper, we present an automated method for selecting optimal overlay sampling plans based on a systematic evaluation of the spatial variation components of overlay errors, overlay prediction errors, sampling confidence, and yield loss due to inadequate sampling. Generalized nested ANOVA and clustering analysis are used to quantify the major components of overlay variations in terms of stepper-related systematic

Xuemei Chen; Moshe E. Preil; Mathilde Le Goff-Dussable; Mireille Maenhoudt

2001-01-01

131

Combining Multihoming with Overlay Routing (or, How to Be a Better ISP without Owning a Network)  

Microsoft Academic Search

Multihoming and overlay routing are used, mostly separately, to bypass Internet outages, congested links and long routes. In this paper, we examine a scenario in which multihoming and overlay routing are jointly used. Specifically, we assume that an overlay service provider (OSP) aims to offer its customers the combined benefits of multihoming and overlay routing, in terms of improved performance,

Yong Zhu; Constantinos Dovrolis; Mostafa H. Ammar

2007-01-01

132

Use of Landsat data to assess waterfowl habitat quality  

USGS Publications Warehouse

This report is a discussion of the feasibility of using Landsat data to generate information of value for effective management of migratory waterfowl. Effective management of waterfowl includes regulating waterfowl populations through hunting regulations and habitat management. This report examines the ability to analyze annual production by monitoring the number of breeding and brood ponds that are present, and the ability to assess waterfowl habitat based on the various relationships between ponds and the surrounding upland terrain types. The basic conclusions of this report are that: 1) Landsat data can be used to improve estimates of pond numbers which may be correlated with duck production; and 2) Landsat data can be used to generate information on terrain types which subsequently can be used to assess relative waterfowl habitat quality.

Colwell, J. E.; Gilmer, D. S.; Work, E. A., Jr.; Rebel, D.

1978-01-01

133

Fiber-Optic Chemical Sensing with Langmuir Blodgett Overlay Waveguides  

NASA Astrophysics Data System (ADS)

Fiber-optic chemical sensing has been demonstrated with a side-polished single-mode optical fiber, evanescently coupled to chemically sensitive Langmuir Blodgett (LB) overlay waveguides. The sensors exhibit a channel-dropping response centered on a wavelength that is dependent on the thickness and the refractive index of the overlay waveguide. It has been shown that pH-sensitive organic dyes proved to be suitable materials for the formation of an overlay waveguide whereas LB deposition provides the required thickness control. A theoretical model of the sensor response, based on the Kramers Kronig relations and phase matching of the guided modes within the optical fiber and overlay waveguide, shows good agreement with experimental results.

Flannery, Damien; James, Stephen W.; Tatam, Ralph P.; Ashwell, Geoffery J.

1999-12-01

134

Evaluating diffraction based overlay metrology for double patterning technologies  

NASA Astrophysics Data System (ADS)

Demanding sub-45 nm node lithographic methodologies such as double patterning (DPT) pose significant challenges for overlay metrology. In this paper, we investigate scatterometry methods as an alternative approach to meet these stringent new metrology requirements. We used a spectroscopic diffraction-based overlay (DBO) measurement technique in which registration errors are extracted from specially designed diffraction targets for double patterning. The results of overlay measurements are compared to traditional bar-in-bar targets. A comparison between DBO measurements and CD-SEM measurements is done to show the correlation between the two approaches. We discuss the total measurement uncertainty (TMU) requirements for sub-45 nm nodes and compare TMU from the different overlay approaches.

Saravanan, Chandra Saru; Liu, Yongdong; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Acheta, Alden; La Fontaine, Bruno

2008-04-01

135

A Study of CRCP Performance: New Construction vs. Overlay.  

National Technical Information Service (NTIS)

This report documents the performance of several continuously reinforced concrete pavements (CRCP) in Texas. Specifically, it involves a comparison of the performances of CRCP overlays and new CRCP construction for three projects: I35-2(45)175, located in...

J. I. Daniel W. R. Hudson B. F. McCullough

1978-01-01

136

Flexible Pavement Overlay Design by Dynamic Deflections. Phase 2.  

National Technical Information Service (NTIS)

The report summarizes a comprehensive study to develop a flexible pavement overlay design procedure based on Falling Weight Deflectometer (FWD) deflections for the South Carolina Department of Highways and Public Transportation (SCDHPT). The study include...

R. L. Baus A. M. Johnson

1992-01-01

137

Landsat Data Continuity Mission Operational Land Imager: Pre-Launch Performance.  

National Technical Information Service (NTIS)

The Operational Land Imager(OLI) will be the main instrument on Landsat-8 when it launches in 2012. OLI represents a generational change from heritage Landsat instruments in its design but must maintain data continuity with the 30+ year Landsat data archi...

B. Canova B. L. Markham E. Donley E. J. Knight G. Kvaran K. Lee

2011-01-01

138

Calibration of Landsat thermal data and application to water resource studies  

Microsoft Academic Search

The newest in the Landsat series of satellites was launched April 15, 1999. The imagery collected by Landsat is used for a myriad of applications, from coral reef studies to land management. In order to take advantage of Landsat 7 data, the Enhanced Thematic Mapper+ (ETM+) instrument must be calibrated. This study focuses on the immediate postlaunch calibration verification of

John R. Schott; Julia A. Barsi; Bryce L. Nordgren; Nina Gibson Raqueño; Dilkushi de Alwis

2001-01-01

139

Next Generation Landsat Products Delivered Using Virtual Globes and OGC Standard Services  

Microsoft Academic Search

The Landsat Data Continuity Mission (LDCM) is the next in the series of Landsat satellite missions and is tasked with the objective of delivering data acquired by the Operational Land Imager (OLI). The OLI instrument will provide data continuity to over 30 years of global multispectral data collected by the Landsat series of satellites. The U.S. Geological Survey Earth Resources

M. Neiers; J. Dwyer; S. Neiers

2008-01-01

140

Data-driven simulations of the Landsat Data Continuity Mission (LDCM) platform  

Microsoft Academic Search

The Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) are two new sensors being developed by the Landsat Data Continuity Mission (LDCM) that will extend over 35 years of archived Landsat data. In a departure from the whiskbroom design used by all previous generations of Landsat, the LDCM system will employ a pushbroom technology. Although the newly adopted modular

Aaron Gerace; Mike Gartley; John Schott; Nina Raqueño; Rolando Raqueño

2011-01-01

141

A time-series analysis of flood disaster around Lena river using Landsat TM\\/ETM+  

Microsoft Academic Search

Landsat satellite has provided a continuous record of earth observation since 1972, gradually improving sensors (i.e. MSS, TM and ETM+). Already processed archives of Landsat image are now available free of charge from the internet. The Landsat image of 30 m spatial resolution with multiple spectral bands between 450 and 2350 nm is appropriate for detailed mapping of natural resource

Toru Sakai; Shigemi Hatta; Makoto Okumura; Wataru Takeuchi; Tetsuya Hiyama; Gen Inoue

2010-01-01

142

Intraband radiometric performance of the Landsat Thematic Mappers.  

USGS Publications Warehouse

Radiometric characteristics have been examined of the Landsat-4 and Landsat-5 Thematic Mappers (TMs) that can be established without absolute calibration of spectral data. This analysis is based on radiometrically and geometrically raw (B-type) data of both uniform (flat-field) and high-contrast scenes. Subscenes selected for uniform radiance were used to characterized subtle radiometric differences and noise problems. Although the general performance of the Thematic Mappers is excellent, various anomalies that have a magnitude of a few digital levels (DN) or less are quantified. -from Authors

Kieffer, H. H.; Cook, D. A.; Eliason, E. M.; Eliason, P. T.

1985-01-01

143

Mixing materials within zone boundaries using shape overlays  

SciTech Connect

Shape overlays provide a means of statically imposing a physical region containing specified material properties onto a zoned mesh. In the most general case, material interface boundaries are unrelated to mesh zone boundaries, causing zones to contain a mixture of materials, and the mesh itself is not uniform in physical space. We develop and apply an algorithm for shape overlays on nonorthogonal, nonuniform meshes in two dimensions. Examples of shape generation in a multiblock uid dynamics code are shown.

Grandy, J.

1997-04-22

144

An Image Overlay system for medical data visualization  

Microsoft Academic Search

Image Overlay is a computer display technique which superimposes computer images over the user’s direct view of the real world. The images are transformed in real-time so they appear to the user to be an integral part of the surrounding environment. By using Image Overlay with three-dimensional medical images such as CT reconstructions, a surgeon can visualize the data ‘in-vivo’,

Mike Blackwell; Constantinos Nikou; Anthony M. DiGioia; Takeo Kanade

2000-01-01

145

Weld overlaying for corrosion resistance in coal gasification atmospheres  

Microsoft Academic Search

Hardness and tensile testing of weldments which were exposed to a 1% HâS coal gasification atmosphere for 1000 hours at 982°C (1800°F) was completed. Corrosion evaluation of unwelded specimens of 304L, 310 SS and INCOLOY alloy 800H was completed also. The INCONEL Filler Metal 72 and R139 overlays increased and the AWS-ER309 overlays decreased in hardness after exposure. The welding

Sadowski

1979-01-01

146

Distributed Addressing and Routing Architecture for Internet Overlays  

Microsoft Academic Search

\\u000a A growing number of network applications create virtual networks called overlays on top of the Internet. Because advanced\\u000a communication modes such as multicast have not been able to be successfully deployed at the network layer, they are now being\\u000a implemented at the application layer thus creating such virtual networks. However these overlays require some form of addressing\\u000a and routing inside

Damien Magoni; Pascal Lorenz

2005-01-01

147

Coloured overlays and their effects on reading speed: a review.  

PubMed

Coloured overlays can reduce symptoms of visual stress and improve reading speed. These benefits are reliable and are not attributable simply to placebo effects. Five percent of children in mainstream education read at least 25% more quickly with an overlay, provided they have chosen the colour. The suboptimal design of children's text and the high level of classroom lighting may be partly responsible. PMID:12358317

Wilkins, Arnold

2002-09-01

148

AdOn: an intelligent overlay video advertising system  

Microsoft Academic Search

This paper presents a new video advertising system, called AdOn, which supports intelligent overlay video ads. Unlike most current ad-networks such as Youtube that overlay the ads at fixed positions in the videos (e.g., on the bottom fifth of videos 15 seconds in), AdOn is able to automatically detect a set of spatio-temporal nonintrusive positions and associate the contextually relevant

Jinlian Guo; Tao Mei; Falin Liu; Xian-sheng Hua

2009-01-01

149

Application of mark diagnostics to overlay metrology  

NASA Astrophysics Data System (ADS)

A suit of novel diagnostics and culling software for the BioRad Quaestor optical metrology system has been developed and used to improve the overlay (O/L) metrology. It is based on verification of the a priori constraints in images of the target and bullet levels of the O/L measurement marks. The software makes use of the base Quaestor edge detection and matching algorithms to produce two centerlines per level per axis mark detection, rather than one. This enables computation of measures of redundancy or symmetry in images of O/L measurement marks. Such measures of uncertainty of centerline estimation, rather than the values of measured O/L, are the basis for data culling against the user- defined tolerances. Having passed the culling, average centerline is used in the estimate of O/L. The new Quaestor software is shown to result in significant reduction of uncertainty of resulting measurements. Metrology available with the new software is compared to conventional and illustrated with examples. Based on the diagnostics generated by the tool, modifications of O/L mark design, placement, and process of mark formation are pursued with the objective of reducing the net uncertainty of O/L measurements.

Goodwin, Norman H.; Starikov, Alexander; Robertson, Grant

1992-06-01

150

Overlay Text Retrieval From Video Scene  

NASA Astrophysics Data System (ADS)

The rapid growth of video data leads to an urgent demand for efficient and true contentbased browsing and retrieving systems. In response to such needs, various video content analysis schemes using one or a combination of image, audio, and text information in videos have been proposed to parse, index, or abstract massive amount of data text in video is a very compact and accurate clue for video indexing and summarization. Most video text detection and extraction methods hold assumptions on text color, background contrast, and font style. Moreover, few methods can handle multilingual text well since different languages may have quite different appearances. In this paper, an efficient overlay text detection and extraction method is implemented which deals with complex backgrounds. Based on our observation that there exist transient colors between inserted text and its adjacent background. It is robust with respect to font size, style text, color, orientation and noise and can be used in a large variety of application fields such as mobile robot navigation vehicle license detection and recognition, object identification , document retrieving, etc.

Manohar, K.; Irfan, S.; Sravani, K.

2013-03-01

151

Performance evaluation of a method to reduce inter-ISP transit cost caused by overlay routing  

Microsoft Academic Search

Overlay routing is an application-level routing mechanism and existing research has revealed that overlay routing can improve user-perceived performance. On the other hand, overlay routing may harm the ISPs' cost structure because of the policy mismatch between IP routing and overlay routing. In a previous study, we proposed a method to reduce inter-ISP transit cost caused by overlay routing while

Kazuhito MATSUDA; G. Hasegawa; S. Kamei; M. Murata

2010-01-01

152

``Electric growth`` of metal overlayers on semiconductor substrates  

SciTech Connect

In this article, the authors present the main results from their recent studies of metal overlayer growth on semiconductor substrates. They show that a variety of novel phenomena can exist in such systems, resulting from several competing interactions. The confined motion of the conduction electrons within the metal overlayer can mediate a surprisingly long-range repulsive force between the metal-semiconductor interface and the growth front, acting to stabilize the overlayer. Electron transfer from the overlayer to the substrate leads to an attractive force between the two interfaces, acting to destabilize the overlayer. Interface-induced Friedel oscillations in electron density can further impose an oscillatory modulation onto the two previous interactions. These three competing factors, of all electronic nature, can make a flat metal overlayer critically, marginally, or magically stable, or totally unstable against roughening. The authors further show that, for many systems, these electronic effects can easily win over the effect of stress. First-principles studies of a few representative systems support the main features of the present electronic growth concept.

Zhang, Z.; Cho, J.H. [Oak Ridge National Lab., TN (United States). Solid State Div.]|[Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy; Niu, Q.; Shih, C.K. [Univ. of Texas, Austin, TX (United States). Dept. of Physics; Suo, Z. [Princeton Univ., NJ (United States)

1998-02-01

153

Inference of landslide susceptible areas by Landsat Thematic Mapper data  

Microsoft Academic Search

Geological structure and the exceptional water retention characteristic of soil, said to be the major factors that causes landslide in the upper basin of the Yoshino river in Shikoku Island, Japan. An indirect approach to estimate landslide susceptible areas in this river basin was investigated using Landsat Thematic Mapper (TM) data. Inference of landslide potential areas was made by investigating

L. SAMARAKOON; S. OGAWA; N. EBISU; R. LAPITAN; Z. KOHKI

1993-01-01

154

Landsat and multispectral imagery utilization in the U. S. Army  

SciTech Connect

The developing use of multispectral imagery (MSI) by the U.S. Army, in particular that produced by Landsat and SPOT, is discussed. The role of MSI in operations Desert Shield and Desert Storm is emphasized. Ongoing projects for future military uses of MSI are addressed.

Krieger, R.H. Jr. (U.S. Army, Space Command, Colorado Springs, CO (United States))

1992-03-01

155

The Kuwait oil fires as seen by Landsat  

Microsoft Academic Search

A mosaic of two Landsat thematic mapper images acquired May 30, 1991, reveals a dark smoke plume 30-60 km wide extending hundreds of kilometers south of Kuwait City along the Persian Gulf. Smoke coming from the Raudhatain and Sabriyah oil fields blew across the Gulf of Kuwait and over Kuwait City, joined with smoke from the Greater Burgan and Minagish

Robert F. Cahalan

1992-01-01

156

Multispectral Image Maps from Landsat Thematic Mapper Data.  

National Technical Information Service (NTIS)

This report describes a capability to produce prototype 1:50,000 scale multispectral image maps using Landsat TM data. These image maps are in the standard UTM projection, contain imbedded 1,000 meter grid lines with labeled UTM coordinates, and can easil...

D. A. Davis J. E. Anderson R. S. Rand

1991-01-01

157

Absolute calibration of Landsat instruments using the moon.  

USGS Publications Warehouse

A lunar observation by Landsat could provide improved radiometric and geometric calibration of both the Thematic Mapper and the Multispectral Scanner in terms of absolute radiometry, determination of the modulation transfer function, and sensitivity to scattered light. A pitch of the spacecraft would be required. -Authors

Kieffer, H. H.; Wildey, R. L.

1985-01-01

158

Effect of the Atmosphere on the Classification of LANDSAT Data  

Microsoft Academic Search

The purpose of this work was to develop a suitable computer program to correct computer compatible tapes, obtained from LANDSAT MSS data, and to study its effect on percentage of correct classification. The LOWTRAN-3 program, developed by the Air Force Geophysics Laboratories and based on a semi-empirical model, was used to calculate the atmospheric transmittance, in conjunction with Turner's model

Tsutomu Morimoto; Ravindra Kumar; Luiz Carlos Baldicero Molion

1979-01-01

159

Spectral Shape Classification System for Landsat The matic Mapper  

Microsoft Academic Search

A multispectral classification system based on an alternative spectral representation is described and its perfor mance over a full Landsat Thematic Mapper (TM) scene evaluated. Spectral classes are represented by their s pectral shape - a vector of binary features that describes the relative values between spectral bands. An algorit hm for segmenting or clustering TM data based on this

Mark J. Carlotto

1996-01-01

160

Spectral shape classification system for Landsat thematic mapper  

Microsoft Academic Search

A multispectral classification system based on an alternative spectral representation is described and its performance over a full landsat thematic mapper (TM) scene evaluated. Spectral classes are represented by their spectral shape -- a vector of binary features that describes the relative values between spectral bands. An algorithm for segmenting or clustering TM data based on this representation is described.

Mark J. Carlotto

1996-01-01

161

Monitoring Forest Succession Using Multitemporal Landsat Images: Factors of Uncertainties  

NASA Astrophysics Data System (ADS)

This study evaluates uncertainty factors in using multitemporal Landsat images for subtle change detection, including atmosphere, topography, phenology, sun and view angles. The study is based on monitoring forest succession with a set of multiple Landsat TM/ETM+ images spanning 15 years over the H. J. Andrews Experimental Forest in the Western Cascades of Oregon. The algorithms for removing atmospheric effects from remotely sensed images evaluated include a new version of dark object subtraction (DOS3) method, the dense dark vegetation (DDV) method, the path radiance (PARA) approach, and the 6S radiative transfer codes. We found that the DOS3 approach under-corrects the image, and the recently developed DDV and PARA approaches can produce surface reflectance values closely matching those produced by 6S using in situ measurements of atmospheric aerosol optical depth. Atmospheric effects reduce NDVI and Greenness, and increase Brightness and Wetness. Topography modifies Brightness and Greenness, but has minimal effects on NDVI and Wetness, and it interacts with sun angle. Forest stands at late successional stages are more sensitive to topography than younger stands. Though the study areas are covered predominantly by evergreen needle leaf forests, phenological effect is significant. Sun angle effects are confounded with phenology, and reflectance values for stands at different successional stages are related to sun angles nonlinearly. Though Landsat has a small field of view angle, the view angle effects from overlapping Landsat scenes for a mountainous forested landscape may not be ignored when monitoring forest succession with multitemporal images.

Song, C.

2004-05-01

162

Witness the Launch of the next Landsat Satellite  

NASA Website

NASA will host a two-day event for 80 of its social media followers on ­­­­­­Sunday, Feb. 10, and Monday, Feb. 11, at Vandenberg Air Force Base in Lompoc, Calif., for the launch of the Landsat Data Continuity Mission, a satellite that continues a ...

163

Landsat5 TM reflective-band absolute radiometric calibration  

Microsoft Academic Search

The Landsat-5 Thematic Mapper (TM) sensor provides the longest running continuous dataset of moderate spatial resolution remote sensing imagery, dating back to its launch in March 1984. Historically, the radiometric calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset of each detector. Due to observed

Gyanesh Chander; Dennis L. Helder; Brian L. Markham; James D. Dewald; E. Kaita; Kurtis J. Thome; Esad Micijevic; Timothy A. Ruggles

2004-01-01

164

Discrimination of sugarcane varieties using Landsat 7 ETM+ spectral data  

Microsoft Academic Search

This study addresses the identification of sugarcane varieties using data from an orbital?borne sensor in an attempt to reduce evaluation time and field?checking efforts. It would help institutions that breed sugarcane varieties for royalties charges for the propagation of their genetic material. The approach of this work was to apply a methodology to discriminate sugarcane varieties through Landsat 7 Enhanced

C. Fortes; J. A. M. Demattê

2006-01-01

165

Landsat Imagery of the Venetian Lagoon: A Multitemporal Analysis.  

National Technical Information Service (NTIS)

The use of LANDSAT multispectral scanner images from 1975 to 1979 to determine pollution dispersion in the central basin of the lagoon under varying tidal conditions is described. Images taken during the late spring and representing both short and long ra...

L. Alberotanza A. Zandonella

1980-01-01

166

Deforestation measured by LANDSAT: steps toward a method  

SciTech Connect

The magnitude of the annual carbon flux due to deforestation is a function of the rate of deforestation and biotic factors including biomass, soil organic matter, and the fraction of the stock of organic matter oxidized following disturbance. Immediate improvement in estimation of the carbon flux to the atmosphere depends on reducing the uncertainty in estimates of rates of deforestation. The greatest potential for new data lies in the use of remote sensing, especially satellite. The LANDSAT system determines net change in the area of forests, and therefore in the amount of carbon held in terrestrial systems, globally. The work required development of a model based on forest succession, the MBL-TCM, designed to accommodate changes in area of forests regionally as well as successional changes following disturbance or the abandonment of land. Three approaches to the use of LANDSAT data for this purpose seemed possible. First, if a sufficiently detailed classification of vegetation can be made from a single LANDSAT image, an estimate of net flux is possible through use of a model. This is the single image approach. Second, LANDSAT imagery might be used to construct two classification inventories of the amount of carbon in the vegetation at different dates. Fianlly, the technique of change detection using satellite imagery might be applied by substracting the digital information in a later image from a former image to produce a third data set that records only the changes.

Woodwell, G.M.; Hobbie, J.E.; Houghton, R.A.; Melillo, J.M.; Peterson, B.J.; Shaver, G.R.; Stone, T.A.; Moore, B.; Park, A.B.

1983-06-01

167

The Evolution of Landsat Data Systems and Science Products  

NASA Astrophysics Data System (ADS)

The series of Landsat satellite missions have collected observations of the Earth's surface since 1972, resulting in the richest archive of remotely sensed data covering the global land masses at scales from which natural and human-induced changes can be distinguished. This observational record will continue to be extended with the launch of the Landsat Data Continuity Mission, or Landsat 8, in December of 2012 carrying the Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) instruments. The data streams from these instruments will be significantly enhanced yet compatible with data acquired by heritage Landsat instruments. The radiometry and geometry of the OLI and TIRS data will be calibrated and combined into single, multi-band Level-1 terrain-corrected image products. Coefficients will be included in the product metadata to convert OLI to at-sensor radiance or reflectance and to convert TIRS data to at-aperture radiances. A quality assurance band will contain pixel-based information regarding the presences or clouds, shadows, and terrain occlusion. The raw data as well as the Level-1 products will be stored online and made freely accessible through web coverage services. Rescaled Level-1 OLI and TIRS images will be made available via web mapping services to enable inventory searches and for ready use in geospatial applications. The architecture of the Landsat science data processing systems is scalable to accommodate additional processing and storage nodes in response to archive growth and increased demands on processing and distribution. The data collected by the various Landsat instruments have been inter-calibrated to enable the generation of higher level science data products that are of consistent quality through time and from which geophysical and biophysical parameters of the land surface can be derived for use in process models and decision support systems. Data access and delivery services have evolved in response to increasing demand for Landsat data in a broad range of applications, and the demand for additional processing capabilities and services is expected to grow in the future to meet the needs for climate data records and essential climate variables.

Dwyer, J. L.

2011-12-01

168

Detecting air pollution stress in southern California vegetation using Landsat Thematic Mapper band data  

SciTech Connect

Landsat Thematic Mapper (TM) and aircraft-borne Thematic Mapper simulator (TMS) data were collected over two areas of natural vegetation in southern California exposed to gradients of pollutant dose, particularly in photochemical oxidants: the coastal sage scrub of the Santa Monica Mountains in the Los Angeles basin, and the yellow pine forests in the southern Sierra Nevada. In both situations, natural variations in canopy closure, with subsequent exposure of understory elements (e.g.,rock or soil, chaparral, grasses, and herbs), were sufficient to cause changes in spectral variation that could obscure differences due to visible foliar injury symptoms observed in the field. TM or TMS data are therefore more likely to be successful in distinguishing pollution injury from background variation when homogeneous communities with closed canopies are subjected to more severe pollution-induced structural and/or compositional change. The present study helps to define the threshold level of vegetative injury detectable by TM data. 26 references.

Westman, W.E.; Price, C.V.

1988-09-01

169

Overlay budget considerations for an all-scanner fab  

NASA Astrophysics Data System (ADS)

According to the SIA roadmap an overlay of 65nm is necessary for state of the art 0.18micrometers processes. To meet such tight requirements it is necessary to know the magnitude of all contributions, to understand possible interactions and to try to drive every individual overlay component to its ultimate lower limit. In this experimental study we evaluate the impact of different contributions on the overall overlay performance in a fab equipped exclusively with ASML step and scan systems. First we discuss the overlay performance of advanced step and scan systems in a mix and match scenario, focusing on single machine overlay, long term stability and multiple machine matching. We show that both distortion and stage differences between different tools are typically less than 22nm, justifying a multiple machine scenario without significant loss of overlay performance. In the next step, we discuss the impact of layer deposition and CMP. We include shallow trench isolation, tungsten-CMP as well as conventional aluminum wiring and copper-dual-damascene technology into our examinations. In particular, we discuss the pro's and con's of using a zero-layer-mark-approach, compared to an alignment on marks formed in certain layers for direct layer to layer alignment. Furthermore, we examine the performance of ASMLs 'through-the-lens' (TTL)-alignment system becomes as small as 6nm using TTL-alignment. For marks directly affected by CMP-processes technology impact can be controlled within 13nm. We show that, even in a scenario with multiple tools matched to each other, where alignment marks are directly affected by a CMP process step, and where the standard TTL alignment marks are directly affected by a CMP process step, and where the standard TTL alignment system is used, the overall overlay can be controlled within 60nm. Using the ATHENA alignment system, a further improvement is possible.

Seltmann, Rolf; Demmerle, Wolfgang; Staples, Marc; Minvielle, Anna Maria; Schulz, Bernd; Muehle, Sven

2000-07-01

170

Retrieving Moderate Resolution Biophysical Parameters by Fusing Landsat-like Data and MODIS Land Products  

NASA Astrophysics Data System (ADS)

Landsat data have been successfully used for retrieving biophysical parameters and serve as an important validation source for coarser-resolution satellite instruments such as MODIS. A continuous Landsat data record is critical for many applications. However, the scan-line corrector problem on Landsat 7 and the age of Landsat 5 are threatening the continuity of Landsat data record before a new Landsat mission starts operation. Landsat- like data sources such as the Advanced Wide Field Sensor (AWiFS) aboard the Indian Remote Sensing Satellite (IRS), the Charge Coupled Device (CCD) camera aboard the China-Brazil Earth Resources Satellite (CBERS), and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard EOS/TERRA have spatial resolutions and bandwidths similar to Landsat TM/ETM+. They are good candidates for mitigating a possible gap in Landsat operations and thus reducing Landsat program risk. However, different acquisition times and the lack of blue or thermal band limit their abilities in retrieving surface reflectance and biophysical properties. Two approaches have been developed to retrieve biophysical parameters for these Landsat-like data sources. First, a relative atmosphere correction approach was developed to correct AWiFS data to surface reflectance using MODIS surface reflectance as reference. The corrected surface reflectance is consistent with MODIS surface reflectance through one step processing and thus biophysical parameters such as leaf area index (LAI) can be retrieved based on the corrected surface reflectance using MODIS algorithms. The same approach can be extended to other Landsat-like data sources (CBERS, ASTER) for retrieving biophysical products. Second, a general empirical relation model (GERM) was developed to relate satellite digital number (DN) with MODIS LAI directly through MODIS homogeneous pixels. This approach will be demonstrated using Landsat/Landsat-like data and the MODIS LAI product. These results show the power of combining multi-resolution data sources for land parameter retrievals, using MODIS as a reference data set.

Gao, F.; Masek, J.

2007-12-01

171

MONITORING LARGE AREAS FOR FOREST CHANGE USING LANDSAT: GENERALIZATION ACROSS SPACE, TIME AND LANDSAT SENSORS. (R828309)  

EPA Science Inventory

Landsat 7 ETM+ provides an opportunity to extend the area and frequency with which we are able to monitor the Earth's surface with fine spatial resolution data. To take advantage of this opportunity it is necessary to move beyond the traditional image-by-image approac...

172

Overlay control using scatterometry based metrology (SCOMTM) in production environment  

NASA Astrophysics Data System (ADS)

The newly emerging lithographic technologies related to the 32nm node and below will require a step function in the overlay metrology performance, due to the dramatic shrinking of the error budgets. In this work, we present results of an emerging alternative technology for overlay metrology - Differential signal scatterometry overlay (SCOTM). The technique is based on spectroscopic analysis of polarized light, reflected from a "grating-on-grating" target. Based on theoretical analysis and initial data, this technology, as well as broad band bright field overlay, is a candidate technology that will allow achieving the requirements of the 32nm node and beyond it. We investigate the capability of SCOLTM to control overlay in a production environment, on complex stacks and process, in the context of advanced DRAM and Flash technologies. We evaluate several metrology mark designs and the effect on the metrology performance, in view of the tight TMU requirements of the 32nm node. The results - achieved on the KLA-Tencor's Archer tool, equipped with both broad band bright field AIMTM and scatterometry SCOLTM sensors - indicate the capability of the SCOLTM technology to satisfy the advanced nodes requirements.

Dinu, Berta; Fuchs, Stefan; Kramer, Uwe; Kubis, Michael; Marchelli, Anat; Navarra, Alessandra; Sparka, Christian; Widmann, Amir

2008-04-01

173

Instructional geographic information science Map overlay and spatial abilities  

NASA Astrophysics Data System (ADS)

The fundamental goal of this study is to determine if the complex spatial concept of map overlay can be effectively learned by young adolescents through the utilization of an instructional technique based within the foundations of Instructional Geographic Information Science (InGIScience). Percent correct and reaction times were the measures used to analyze the ability of young adolescents to learn the intersect, erase, and union functions of map overlay. The ability to solve for missing inputs, output, or function was also analyzed. Young adolescents of the test group scored higher percent correct and recorded faster reaction times than those of the control group or adults of the expert group by the end of the experiment. The intersect function of map overlay was more difficult in terms of percent correct and reaction time than the erase or union functions. Solving for the first or second input consistently resulted in lower percent correct and higher reaction times throughout the experiment. No overall performance differences were shown to exist between males and females. Results of a subjective "real-world" test also indicated learning by young adolescents. This study has shown that the practice of repetitive instruction and testing has proven effective for enhancing spatial abilities with regard to the map overlay concept. This study found that with practice, young adolescents can learn the map overlay concept and perform at levels equal to or greater than adults. This study has helped to answer the question of whether this development of spatial abilities is possible.

Tricot, Thomas Alexander, II

174

Overlay target design characterization and optimization for tungsten CMP  

NASA Astrophysics Data System (ADS)

As the semiconductor industry pushes design rules to 0.25 micron and below, tungsten chemical mechanical polishing (WCMP) is emerging as a key process that reduces defect density, increases circuit density and improves yield. However, due to the non-selective nature of the WCMP process, the stepper alignment marks and the overlay metrology target can be seriously damaged during the polishing process. The result of this damage may contribute to the total misregistration error. This paper describes a systematic overlay target optimization on various WCMP layers in order to evaluate and reduce target and measurement noise. Eight different target designs were evaluated on three different metal layers. The quantification of overall measurement counts, measurement precision, modeled residual, and kernel analysis was used as the metric for determining the overall effectiveness of each overlay target design. Short and long term gauge studies were performed to verify the measurement capability of the metrology tool. An experiment was performed in which a known offset was introduced on the stepper to confirm that the overlay measurement responded accordingly. To verify the robustness of the target, oxide thickness, tungsten thickness and polish time were varied on one of the three layers. The measured overlay error was also correlated to cross-section scanning electron microscope (SEM) results.

Hsu, Stephen D.; Dusa, Mircea V.; Vlassak, Joost; Harker, Cameron; Zimmerman, Michelle

1998-06-01

175

Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays  

NASA Astrophysics Data System (ADS)

The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

Dubois, Cameron; Ramseyer, Chris

2010-10-01

176

A drainage system analysis evaluation of, and comparison between, Landsat3 RBV, Landsat5 TM and SPOT PA imageries covering the Central Macedonia district, Greece  

Microsoft Academic Search

Landsat-3 RBV, Landsat-5 TM imageries and SPOT PA stereopair diapositives were visually interpreted for the purpose of finding the accuracy of certain morphometric variables of three drainage basin sample areas in Central Macedonia, North Greece, drawn separately from each of the above three types of satellite imageries and comparisons were made between the efficiency of drainage systems drawn from each

T. Astaras; N. Lambrinos; N. Soulakellis

1990-01-01

177

Diffraction-based overlay for spacer patterning and double patterning technology  

NASA Astrophysics Data System (ADS)

Overlay performance will be increasingly important for Spacer Patterning Technology (SPT) and Double Patterning Technology (DPT) as various Resolution Enhancement Techniques are employed to extend the resolution limits of lithography. Continuous shrinkage of devices makes overlay accuracy one of the most critical issues while overlay performance is completely dependent on exposure tool. Image Based Overlay (IBO) has been used as the mainstream metrology for overlay by the main memory IC companies, but IBO is not suitable for some critical layers due to the poor Tool Induced Shift (TIS) values. Hence new overlay metrology is required to improve the overlay measurement accuracy. Diffraction Based Overlay (DBO) is regarded to be an alternative metrology to IBO for more accurate measurements and reduction of reading errors. Good overlay performances of DBO have been reported in many articles. However applying DBO for SPT and DPT layers poses extra challenges for target design. New vernier designs are considered for different DPT and SPT schemes to meet overlay target in DBO system. In this paper, we optimize the design of the DBO target and the performance of DBO to meet the overlay specification of sub-3x nm devices which are using SPT and DPT processes. We show that the appropriate vernier design yields excellent overlay performance in residual and TIS. The paper also demonstrated the effects of vernier structure on overlay accuracy from SEM analysis.

Lee, Byoung Hoon; Park, Jeongsu; Lee, Jongsu; Park, Sarohan; Lim, Changmoon; Yim, Dong-Gyu; Park, Sungki; Ryu, Chan-Ho; Morgan, Stephen; van de Schaar, Maurits; Fuchs, Andreas; Bhattacharyya, Kaustuve

2011-03-01

178

Measured residual stresses in overlay pipe weldments removed from service  

SciTech Connect

Surface and throughwall residual stresses were measured on an elbow-to-pipe weldment that had been removed from the Hatch-2 reactor about a year after the application of a weld overlay. The results were compared with experimental measurements on three mock-up weldments and with finite-element calculations. The comparison shows that there are significant differences in the form and magnitude of the residual stress distributions. However, even after more than a year of service, the residual stresses over most of the inner surface of the actual plant weldment with an overlay were strongly compressive. 3 refs., 7 figs.

Shack, W.J.

1985-02-01

179

An international geostationary overlay for GPS and GLONASS  

NASA Astrophysics Data System (ADS)

The concept of employing nonautonomous satellite repeaters on geostationary hosts for civil radionavigation, especially for integrity broadcast and for coverage augmentation, is reviewed. It is suggested that a worldwide geostationary overlay can be more economical than launching additional autonomous navigation satellites. Also presented are recently developed technical considerations for the geostationary overlay concept, including design parameters for the navigation package, signal and data format considerations for augmentation and integrity, and ground network concepts for generating and timing the uplink signal. Early results of a test program being conducted with transmission of GPS-like signals via an existing L-band mobile communications satellite are reported.

Kinal, G. V.; Singh, J. P.

180

SLC-off Landsat-7 ETM+ reflective band radiometric calibration  

USGS Publications Warehouse

Since May 31, 2003, when the scan line corrector (SLC) on the Landsat-7 ETM+ failed, the primary foci of Landsat-7 ETM+ analyses have been on understanding and attempting to fix the problem and later on developing composited products to mitigate the problem. In the meantime, the Image Assessment System personnel and vicarious calibration teams have continued to monitor the radiometric performance of the ETM+ reflective bands. The SLC failure produced no measurable change in the radiometric calibration of the ETM+ bands. No trends in the calibration are definitively present over the mission lifetime, and, if present, are less than 0.5% per year. Detector 12 in Band 7 dropped about 0.5% in response relative to the rest of the detectors in the band in May 2004 and recovered back to within 0.1% of its initial relative gain in October 2004.

Markham, B. L.; Barsi, J. A.; Thome, K. J.; Barker, J. L.; Scaramuzza, P. L.; Helder, D. L.

2005-01-01

181

Landsat thermal band efficiency on characterizing mulched soil surface  

NASA Astrophysics Data System (ADS)

In order to study petroleum mulch effects on soil, and sand dune fixation, thermal, and reflective bands of Landsat thematic mapper TM and ETM data, and other sources of information including topographic maps, aerial photos, and field work were used. The methodology was comprised of: images processing, statistic analysis, and relationship between thermal and reflective data. The results from image processing show that the behaviour of the Landsat thermal data is completely different from reflective data. The results from colour composite images including thermal bands have shown the capability of thermal bands in reparability of mulched and non-mulched areas. It was generally concluded that selection of TM, ETM thermal band is an important step to evaluate the area covered with petroleum mulch. Ratio mulch index was introduced as a best band combination in order to imagine mulch decomposition.

Hashemimanesh, M.; Matinfar, H.; Alavipanah, S.; Zehtabian, G.

2012-07-01

182

Landsat analysis for uranium exploration in Northeast Turkey  

USGS Publications Warehouse

No uranium deposits are known in the Trabzon, Turkey region, and consequently, exploration criteria have not been defined. Nonetheless, by analogy with uranium deposits studied elsewhere, exploration guides are suggested to include dense concentrations of linear features, lineaments -- especially with northwest trend, acidic plutonic rocks, and alteration indicated by limonite. A suite of digitally processed images of a single Landsat scene served as the image base for mapping 3,376 linear features. Analysis of the linear feature data yielded two statistically significant trends, which in turn defined two sets of strong lineaments. Color composite images were used to map acidic plutonic rocks and areas of surficial limonitic materials. The Landsat interpretation yielded a map of these exploration guides that may be used to evaluate relative uranium potential. One area in particular shows a high coincidence of favorable indicators.

Lee, Keenan

1983-01-01

183

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, October 1994--December 1994.  

National Technical Information Service (NTIS)

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. Al...

B. F. Levin J. N. Dupont A. R. Marder

1995-01-01

184

Assessment of the Potential for Color Overlays to Enhance the Reading Skills of Enlisted Navy Recruits.  

National Technical Information Service (NTIS)

Meares Irlen Syndrome (MIS) is a perceptual difficulty associated with visual complaints that appear to be largely alleviated by individually selected color overlay(s) or tinted lenses. The current study was designed to assess the prevalence of MIS sympto...

C. U. Ekenna-Kalu N. Momen

2006-01-01

185

Design and Construction of Asphalt Overlays and Hot-Mix Asphalt Construction Practices.  

National Technical Information Service (NTIS)

Contents (Partial): Mechanistically Based Flexible Overlay Design System for Idaho; Construction of Stone Matrix Asphalt Section at Edwards Air Force Base; Performance Evaluation of Asphalt Overlays on Broken and Seated Concrete Pavements; Hot-Mix Asphalt...

1996-01-01

186

Active mud volcanism observed with Landsat 7 ETM+  

Microsoft Academic Search

Mud volcanoes are relatively small spatter cones that erupt water-laden mud and gases, and occur throughout the world. For many mud volcanoes, the eruption of warm mud (10–40°C) can be detected with high-resolution thermal satellite imagery. We demonstrate the utility of Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery for thermal monitoring of active mud volcanism. We constrain the temperature

Matthew Patrick; Kenneson Dean; Jonathan Dehn

2004-01-01

187

ILLUMINATION CORRECTION OF LANDSAT TM DATA IN SOUTH EAST NSW  

Microsoft Academic Search

The NSW Forests Taskforce within Environment Australia purchased multi-temporal Landsat Thematic Mapper (TM) data ranging in dates from 1987 through to 1999 for use in the NSW Regional Forest Agreement (RFA) process. The geometrically and radiometrically corrected multi-temporal mosaics were used to assist in mapping and updating of wilderness areas, old-growth forest and disturbance history layers. The data are also

Elizabeth Roslyn McDonald; Xiaoliang Wu; Peter Caccetta; Norm Campbell

188

INTRABAND RADIOMETRIC PERFORMANCE OF THE LANDSAT 4 THEMATIC MAPPER.  

USGS Publications Warehouse

This preliminary report examines those radiometric characteristics of the Landsat 4 Thematic Mapper (TM) that can be established without absolute calibration of spectral data. Analysis is based largely on radiometrically raw (B type) data of three daytime and two nighttime scenes; in most scenes, a set of 512 lines were examined on an individual-detector basis. Subscenes selected for uniform-radiance were used to characterize subtle radiometric differences and noise problems.

Kieffer, Hugh, H.; Eliason, Eric, M.; Chavez, Jr. , Pat, S.

1985-01-01

189

Creating Landsat Images from Raw Data: San Francisco - Oakland  

NSDL National Science Digital Library

These images are compressed versions of high definition television (HDTV) images showing how Landsat data, which spans a very broad swatch of the electromagnetic spectrum, can be turned into images. The TIFF versions of these images are full resolution HDTV frames (1920 x 1080). All images have the HDTV standard aspect ratio (16:9). The Thematic Mapper (TM) on Landsat 4 and 5 observes reflected sunlight from the Earth all the way from blue in the visible part of the electromagnetic spectrum to shortwave infrared well beyond the ability of the human eye to percieve. The TM instrument also can observe infrared radiation actively emitted by the Earth from thermal infrared radiation. Landsat 7 carries an improved version of the TM instrument, called ETM+. In addition to 7 channels of spectral data collected by the older TM instruments, ETM+ can observe in a special panchromatic band spanning the entire visible spectrum at twice the resolution of the TM bands (15 meter resolution instead of 30 meters). The ETM+ also has a major improvement in the resolution of the thermal band (60 meter resolution instead of 160 meters). A standard way to create images from raw Landsat TM and ETM+ data is to display a single band as a primary color, then combine different bands to create a full color image. Images shown here demonstrate combining three bands to make a color image using TM bands 5, 4, & 2, which covers a very broad range of the TM's spectral coverage. It is also shown in combination with a digital elevation model. Terrain data is shown with vertical features exagerated by a factor of three to emphasize details.

Allen, Jesse; Williams, Darrel

1999-04-09

190

Calculation of lava effusion rates from Landsat TM data  

Microsoft Academic Search

We present a thermal model to calculate the total thermal flux for lava flowing in tubes, on the surface, or under shallow\\u000a water. Once defined, we use the total thermal flux to estimate effusion rates for active flows at Kilauea, Hawaii, on two\\u000a dates. Input parameters were derived from Landsat Thematic Mapper (TM), field and laboratory measurements. Using these parameters

Andrew J. L. Harris; Luke P. Flynn; Laszlo Keszthelyi; Peter J. Mouginis-Mark; Scott K. Rowland; Joseph A. Resing

1998-01-01

191

Linear features determined from Landsat imagery in western Kansas  

USGS Publications Warehouse

A map (scale 1:500,000) shows the linear features determined from Landsat imagery in western Kansas. The linear features, sometimes called linear trends or lineaments, are not identified as to type or origin. Most probably represent fractures or fracture zones, which may affect the movement of water or other fluids through the rocks. The linear features are classified as to length--less than 30 miles and more than 30 miles. (USGS)

Cooley, M. E.

1984-01-01

192

Analysis of coregistered Landsat, Seasat and SIR-A images of varied terrain types  

NASA Astrophysics Data System (ADS)

Multisensor image data (SIR-A, Seasat SAR and Landsat MSS) over areas in northern Algeria and eastern Utah have been coregistered in order to assess the complementary effects of the orbital sensors for geologic mapping in two very different terrains. This first attempt at registering such a data set shows that the radar backscatter information provided by the SIR-A image increases the classification accuracy of several geologic units over the Landsat image alone, and over combined Landsat and Seasat images.

Rebillard, Philippe; Evans, Diane

1983-04-01

193

A Study of the Performance Potential of DHT-based Overlays  

Microsoft Academic Search

We use simulation to study whether overlays basedon the recent distributed hash tables (DHTs) havethe potential to deliver performance comparableto that of overlays based on measurements. Ourwork is motivated by the use of DHTs for servicessuch as multicast, which is already targeted bymeasurement-based overlays; there is currently littleunderstanding of how the two approaches compareat scales where both are viable.

Sushant Jain; Ratul Mahajan; David Wetherall

2003-01-01

194

Evaluation of Thin Epoxy Systems Overlays for Concrete Bridge Decks.  

National Technical Information Service (NTIS)

Four overlay systems were applied to concrete bridge decks in north Louisiana in May 1985 to evaluate their performance as friction surfaces primarily and also as concrete sealers. Dural Flexolith, Poly-Carb Flexogrid, and Con/Chem Cono/Crete were placed ...

M. Rasoulian N. Rabalais

1991-01-01

195

Concrete Overlay as a Rehabilitation Option for Distressed Asphalt Pavements  

Microsoft Academic Search

Ultra-thin Whitetopping (UTW) involves placing a very thin concrete overlay 50 mm to 100 mm thick (2”-4”) on the milled surface of a distressed asphalt pavement. To investigate the performance of UTW placed over a flexible pavement subjected to slow and heavy moving wheel loads, whitetopping mixes were placed over a milled pavement surface in the Accelerated Pavement Testing (APT)

Sudarshan Rajan; J. Olek

2002-01-01

196

Extensive testing ensures success of unusual weld-overlay project  

SciTech Connect

Chevron U.S.A. Inc. has used a unique in situ weld-overlay procedure to repair large process vessels in a hot potassium carbonate CO{sub 2} treating plant. The plant is located on the Sacroc unit near Snyder, Tex. This paper details the project's procedures and execution.

Ferguson, K.R. (Chevron U.S.A. Inc., Midland, TX (US)); Stutheit, A.G. (Chevron U.S.A. Inc., Lafayette, LA (US))

1992-01-13

197

Investigations of magnetic overlayers at the Advanced Photon Source  

SciTech Connect

Magnetic overlayers of Fe and Co have been investigated with x-ray magnetic circular dichroism in x-ray absorption spectroscopy and photoelectron spectroscopy, including spin-resolved photoelectron spectroscopy, at Beamline 4 at the Advanced Photon Source. Particular emphasis was placed upon the interrogation of the 2p levels of the Fe.

Tobin, J.G.; Yu, S.-W.; Butterfield, M.T.; Komesu, Takashi; Waddill, G.D. (Missouri SU); (LLNL)

2010-08-27

198

Tree-assisted gossiping for overlay video distribution  

Microsoft Academic Search

Given its readily deployable nature and broad applications for digital entertainment, video streaming through overlay networks has received much attention recently. While a tree topology is often advocated due to its scalability, it suffers from discontinuous playback under highly dynamic network environments. For on-demand streaming, the asynchronicity among client requests further aggravates the problem. On the other hand, gossip protocols

Jiangchuan Liu; Ming Zhou

2006-01-01

199

T-Man: Gossip-Based Overlay Topology Management  

Microsoft Academic Search

Overlay topology plays an important role in P2P systems. Topology serves as a basis for achieving functions such as routing, search- ing and information dissemination, and it has a major impact on their ef- ficiency, cost and robustness. Furthermore, the solution to problems such as sorting and clustering of nodes can also be interpreted as a topology. In this paper

Márk Jelasity; Özalp Babaoglu

2005-01-01

200

Overlaying Paper Maps with Digital Information Services for Tourists  

Microsoft Academic Search

Despite the increasing availability of various forms of digital maps and guides, paper still prevails as the main information medium used by tourists during city visits. The authors describe how recent technologies for digitally augmented paper maps can be used to develop interactive paper maps that provide value-added services for tourists through digital overlays. An initial investigation into the use

Moira C. Norrie; Beat Signer

2005-01-01

201

A Generic Scheme for Building Overlay Networks in Adversarial Scenarios  

Microsoft Academic Search

This paper presents a generic scheme for a central, yet un- tackled issue in overlay dynamic networks: maintaining stability over long life and against malicious adversaries. The generic scheme maintains desirable properties of the underlying structure including low diameter, and efficient routing mechanism, as well as balanced node dispersal. These desired properties are maintained in a decentral- ized manner without

Ittai Abraham; Baruch Awerbuch; Yossi Azar; Yair Bartal; Dahlia Malkhi; Elan Pavlov

2003-01-01

202

GMAC: An overlay multicast network for mobile agent platforms  

Microsoft Academic Search

The lack of proper support for multicast services in the Internet has hindered the widespread use of applications that rely on group communication services such as mobile software agents. Although they do not require high bandwidth or heavy traffic, these types of applications need to cooperate in a scalable, fair and decentralized way. This paper presents GMAC, an overlay network

Pablo Gotthelf; Alejandro Zunino; Cristian Mateos; Marcelo Campo

2008-01-01

203

12. DETAIL INDICATING TRANSITION FROM ORIGINAL SURFACE TO GUNITE OVERLAY ...  

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

12. DETAIL INDICATING TRANSITION FROM ORIGINAL SURFACE TO GUNITE OVERLAY ON UPSTREAM EMBANKMENT OF DAM (FROM REPAIRS COMPLETED IN 1977) - Upper Doughty Dam, 200 feet west of Garden State Parkway, 1.7 miles west of Absecon, Egg Harbor City, Atlantic County, NJ

204

Overlaying simply connected planar subdivisions in linear time  

Microsoft Academic Search

We present an algorithm which computes the overlay Hb r+ rIg of two Simply connected planar subdivisions ~b and Hg; we assume that ~b (resp. ~) and all its components are colored in blue (resp. green). The algorithm runs in O(n + k) time and space, where n denotes the total nuruber of edges of ~b and IIg and k

Ulrich Finke; Klaus H. Hinrichs

1995-01-01

205

MACEDON: Methodology for Automatically Creating, Evaluating, and Designing Overlay Networks  

Microsoft Academic Search

Currently, researchers designing and implementing large- scale overlay services employ disparate techniques at each stage in the production cycle: design, implemen- tation, experimentation, and evaluation. As a result, complex and tedious tasks are often duplicated leading to ineectiv e resource use and dicult y in fairly com- paring competing algorithms. In this paper, we present MACEDON, an infrastructure that provides

Adolfo Rodriguez; Charles Edwin Killian; Sooraj Bhat; Dejan Kostic; Amin Vahdat

2004-01-01

206

Performance of an Unbonded Concrete Overlay on I-74.  

National Technical Information Service (NTIS)

In Illinois, the typical rehabilitation for a concrete pavement is full-depth patching of the distressed concrete, and overlaying the pavement with 3.25 inches of bituminous concrete. In cases where there are poor joints or extensive durability cracking o...

L. B. Heckel

2002-01-01

207

Cavitation erosion resistance of stellite alloy weld overlays  

Microsoft Academic Search

Stellite alloys have excellent cavitation erosion resistance and are often used for liquid machinery, but the erosion properties of various stellite alloys have not been evaluated by a standard method. In this study, we evaluate the erosion resistance for various stellite alloy weld overlays of ST6 and ST21 in a vibrating method and in a cavitating liquid jet method. The

Shuji Hattori; Norihiro Mikami

2009-01-01

208

Crosslayer Survivability in Overlay-IP-WDM Networks  

ERIC Educational Resources Information Center

|As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

Pacharintanakul, Peera

2010-01-01

209

Field Cooling Rates of Asphalt Concrete Overlays at Low Temperatures.  

National Technical Information Service (NTIS)

Six overlay test sections were placed on an existing test road in Hanover, New Hampshire, to gain experience in compaction of asphalt pavements at rolling temperatures as low as 150 F. The asphalt cement and aggregated used had mix characteristics similar...

R. A. Eaton R. L. Berg

1980-01-01

210

Recovery of Sublethally Injured Bacteria Using Selective Agar Overlays.  

ERIC Educational Resources Information Center

|This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)|

McKillip, John L.

2001-01-01

211

An Overlay Subscription Network for Live Internet TV Broadcast  

Microsoft Academic Search

We propose a framework, called Overlay Subscription Network (OSN), for live Internet TV broadcast, where a subscriber can choose to watch at any time. This framework allows the source server to incrementally build a topology graph that contains the network connections not only from the server to each subscriber, but also among the subscribers themselves. With such a topology graph

Ying Cai; Jianming Zhou

2006-01-01

212

Integrated terrain mapping with digital Landsat images in Queensland, Australia  

USGS Publications Warehouse

Mapping with Landsat images usually is done by selecting single types of features, such as soils, vegetation, or rocks, and creating visually interpreted or digitally classified maps of each feature. Individual maps can then be overlaid on or combined with other maps to characterize the terrain. Integrated terrain mapping combines several terrain features into each map unit which, in many cases, is more directly related to uses of the land and to methods of land management than the single features alone. Terrain brightness, as measured by the multispectral scanners in Landsat 1 and 2, represents an integration of reflectance from the terrain features within the scanner's instantaneous field of view and is therefore more correlatable with integrated terrain units than with differentiated ones, such as rocks, soils, and vegetation. A test of the feasibilty of the technique of mapping integrated terrain units was conducted in a part of southwestern Queensland, Australia, in cooperation with scientists of the Queensland Department of Primary Industries. The primary purpose was to test the use of digital classification techniques to create a 'land systems map' usable for grazing land management. A recently published map of 'land systems' in the area (made by aerial photograph interpretation and ground surveys), which are integrated terrain units composed of vegetation, soil, topography, and geomorphic features, was used as a basis for comparison with digitally classified Landsat multispectral images. The land systems, in turn, each have a specific grazing capacity for cattle (expressed in beasts per km 2 ) which is estimated following analysis of both research results and property carrying capacities. Landsat images, in computer-compatible tape form, were first contrast-stretched to increase their visual interpretability, and digitally classified by the parallelepiped method into distinct spectral classes to determine their correspondence to the land systems classes and to areally smaller, but readily recognizable, 'land units.' Many land systems appeared as distinct spectral classes or as acceptably homogeneous combinations of several spectral classes. The digitally classified map corresponded to the general geographic patterns of many of the land systems. Statistical correlation of the digitally classified map and the published map was not possible because the published map showed only land systems whereas the digitally classified map showed some land units as well as systems. The general correspondence of spectral classes to the integrated terrain units means that the digital mapping of the units may precede fieldwork and act as a guide to field sampling and detailed terrain unit description as well as measuring of the location, area, and extent of each unit. Extension of the Landsat mapping and classification technique to other arid and semi-arid regions of the world may be feasible.

Robinove, Charles Joseph

1979-01-01

213

Computer-based production of bite mark comparison overlays.  

PubMed

Bite mark comparison protocols include measurement and analysis of the pattern, size, and shape of teeth against similar characteristics observed in an injury on skin or a mark on an object. The physical comparison of tooth position often depends upon transparent acetate overlays to detect similarities or differences between the teeth and the bite mark. Several methods are used to produce life-sized comparison overlays. The perimeter of the biting edges of the anterior teeth are usually recorded to produce facsimile images called hollow volume overlays. Some investigators hand-trace these outlines from dental study casts, or from bite exemplars produced in wax, styrofoam, or similar materials. Some use hand-traced outlines from xerographic images produced with office photocopiers that are calibrated to produce life-sized final images. Others use radiographic images and toneline photography of wax exemplars filled with radio-opaque materials, such as metal filings or barium sulfate. Dependence upon subjective input by the odontologist to trace these images manually is considered problematic. This is because the errors incorporated at any production stage are increased in the final product. The authors have developed a method to generate accurate hollow volume overlays using computer-based techniques. A PowerPC Macintosh computer, flatbed scanner, and Adobe Photoshop (a popular graphical interface application) are used to acquire, select, arrange and export detailed data from class and individual characteristics of a suspect's teeth to acetate film loaded in a high-resolution laser printer. This paper describes this technique to enable the odontologist to produce high-quality, accurate comparison overlays without subjective input. PMID:9729824

Sweet, D; Parhar, M; Wood, R E

1998-09-01

214

75 FR 39701 - Revision of a Currently Approved Collection: Users, Uses, and Benefits of Landsat Satellite Imagery  

Federal Register 2010, 2011, 2012, 2013

...Approved Collection: Users, Uses, and Benefits of Landsat Satellite Imagery AGENCY: United States Geological Survey (USGS...1028-0091. Title: Users, Uses, and Benefits of Landsat Satellite Imagery. Type of Request: Revision of a currently...

2010-07-12

215

Overlay improvement by non-linear error correction and non-linear error control by APC  

NASA Astrophysics Data System (ADS)

The continuing downscale of semiconductor fabrication ground rule requires increasingly tighter overlay tolerances, which becomes very challenging at the cutting-edge lithographic node. We need to keep improving overlay performance to admit the requirements of tight overlay budget. The conventional method of overlay control is controlling linear model parameters during alignment and process correction by APC (Advanced Process Control) for linear errors after alignment. Due to this kind of control for linear parameters, this linear error proportion out of total overlay error can be the indicator how well the overlay is being controlled by the conventional overlay control method. After achieving this small proportion of linear error, normally 10 parameters, out of total overlay errors, this conventional method of overlay control face the limitation of improvement and this implies us that it is necessary to work on non-linear overlay error for further improvement. Initial investigation starts from finding out contribution of grid and field for the remained error after 10 parameter linear modeling and the result shows up higher contribution from grid factor. The way to break down grid residual error is by method of control. Nikon provided GCM (Grid Compensation Matching) function which has some options to deal with these non-linear errors, so we tested and simulated a couple of new methods of overlay control to improve the other proportion of total overlay error beside linear overlay error. 1st approach for further improvement was remaining x,y offset feedback through APC for each field after linear modeling and 2nd was non-linear alignment and 3rd is the combination of both methods. This paper will explain which method will improve which part of overlay errors and the test or simulated results of improvement.

Choi, Dongsub; Jahnke, Andreas; Schumacher, Karl; Hoepfl, Max

2006-04-01

216

Measuring Streamwood Accumulations In A Reservoir Using Landsat Imagery  

NASA Astrophysics Data System (ADS)

Streamwood (woody materials greater than 10 cm in diameter and 1 m in length) is important to river networks, providing structure, hydraulic variability, and organic carbon to river ecosystems. In reservoirs where recreational activities take place, streamwood is moved into holding areas to minimize human health hazards. A common disposal method in California is to burn the wood soon after the first rains; streamwood is often insufficiently quantified by managers before disposal. As a result of active management and the loss of longitudinal connectivity caused by dams, streamwood's potential as a geomorphic agent and its biological constituents are lost to downstream ecosystems. To measure how much streamwood can accumulate in a mountain reservoir, Landsat 5 multispectral 30-m resolution imagery was used to aerially quantify streamwood floating on the surface of New Bullard's Bar Reservoir on the North Yuba River, Sierra Nevada, California, in a time-series from 1984 to present. The scientific questions answered by this study were: 1) how much streamwood was transported into the reservoir on a yearly basis? And, 2) what discharge-area relationships exist between gaged discharge and streamwood measures? Landsat images representative of the highest water surface elevation of each year were acquired from the publically available USGS online database, then atmospherically corrected, empirical-line calibrated, and georeferenced using ENVI software. ROIs and spectral library files were developed for four endmembers: forest, water, streamwood, and shoreline, and used in supervised maximum likelihood classifications. An unsupervised isodata classification was also performed, and results were linked to understand areas of confusion and to create a more robust streamwood identification model. A 1-m USGS DOQ image from 1998 and field surveys in 2006 and 2010 were used to ground-truth Landsat results.

Gonzalez, R. L.; Senter, A. E.; Pasternack, G. B.; Ustin, S.

2011-12-01

217

Study of atmospheric diffusion from the LANDSAT imagery  

SciTech Connect

Detailed analyses of the LANDSAT multispectral scanner (MSS) data of the smoke plumes that originated in eastern Cabo Frio (22/sup 0/ 59'S; 42/sup 0/ 02'W) and crossed over into the Atlantic ocean are presented to illustrate how high-resolution LANDSAT imagery can aid meteorologists in evaluating specific air pollution events. The eleven LANDSAT images selected are for different months and years. Conventional interpretation techniques are applied to analyze the images with a view to arrive at certain plume characteristics. The analysis of the visible smoke plumes revealed that the plume was 130 km long and attained a maximum width of 937 m, 10 km away from the chimney emitting the effluent. The results show that diffusion is governed primarily by water and air temperature differences. With colder water, low-level air is very stable and the vertical diffusion is minimal; but water warmer than the air induces vigorous diffusion. The applicability of two empirical methods for determining the horizontal eddy diffusivity coefficient (K/sub y/) in the Gaussian plume formula was evaluated with the estimated standard deviation of the crosswind distribution of material in the plume (sigma/sub y/) from the LANDSAT imagery. Most consistent estimates for K/sub y/ are obtained from the formula based on Taylor's theory of 'diffusion by continuous moment.' K/sub y/ values of about 158 m/sup 2/ ..sigma..)/sup 1/ in quasi-neutral conditions and 49 m/sup 2/ s/sup -1/ in stable conditions are obtained from a plot of sigma/sup 2//sub y/ as a function of distance from the source. The rate of kinetic energy dissipation (epsilon) is evaluated from the diffusion parameters sigma/sub y/ and K/sub y/. The epsilon value ranges from 0.1 x 10/sup -5/ m/sup 2/ s/sup -3/ to 80.2 x 10/sup -5/ m/sup 2/ s/sup -3/ in quasi-neutral and stable stratifications.

Viswanadham, Y.; Torsani, J.A.

1982-11-20

218

Landsat Thematic Mapper monitoring of turbid inland water quality  

SciTech Connect

This study reports on an investigation of water quality calibration algorithms under turbid inland water conditions using Landsat Thematic Mapper (TM) multispectral digital data. TM data and water quality observations (total suspended solids and Secchi disk depth) were obtained near-simultaneously and related using linear regression techniques. The relationships between reflectance and water quality for Green Bay and Lake Michigan were compared with results for Yellowstone and Jackson Lakes, Wyoming. Results show similarities in the water quality-reflectance relationships, however, the algorithms derived for Green Bay - Lake Michigan cannot be extrapolated to Yellowstone and Jackson Lake conditions. 17 refs.

Lathrop, R.G., JR. (Rutgers University, New Brunswick, NJ (United States))

1992-04-01

219

Using Landsat TM data to model corn and soybean yields  

NASA Astrophysics Data System (ADS)

Early research in agriculture used remotely sensed data mostly for the identification of spectral signatures, where crop type/area classification would depend on data acquired from hand-held or truck-mounted instruments. Through time different approaches were taken for crop type/area classification, such as a systematic sampling of inventory ground data that were used later for training and testing using image processing techniques. Later, technology such as the global positioning system (GPS) and geographic information systems (GIS) were used for application to precision agriculture. These new tools provided a better meaning to understand and analyze the complex variability of the crop-soil-atmosphere system to estimate crop yields. The present research used data collected in the Management System Evaluation Area (MSEA) in 1998 and two Landsat thematic Mapper images (July and August) to analyze the crop variability. Ground truth parameters, such as chlorophyll, leaf area index (LAI), and electricity conductivity, were collected throughout the growing season. In addition, vegetation indexes (VI) such as the Normalized difference vegetation index (NDVI), simple vegetation index (SVI), soil adjusted ratio vegetation index (SARVI), were computed for the two images. Both ground truth data and VI's were statistically analyzed with yield measurements taken with an on-the-go yield monitor to estimate a best fit yield model for use with soybeans and corn. The correlation analysis within a Landsat pixel reported SVI52 (r = 0.62), SVI53 (r = 0.56), and SVI54 (r = 0.53) as the most significant relationships. The results from the ground truth data vs. on-the-go yields reported total clay (%) (r = 0.90), leaf area (r = 0.76), and tissue plant analysis (r = 0.73) A stepwise regression analysis was performed using the Landsat TM images and the VI's selected. A series of linear models were evaluated taking into account the Landsat TM and yield while varying the scale (1 pixel to 16 30-m pixels). The same stepwise regression analysis were performed but adding the Digital Elevation Model (DEM) and the Electrical Conductivity (EC) which resulted in the best coefficient of determination (R2 = 0.94, R 2 = 0.98, and R2 = 0.96 for plots 100, 200, and 300, respectively). A stepwise regression analysis was also explored with standardized yields. The resulted models allowed exploring the use of a crop independent model. The corn and soybeans yield models developed with the 1998 data were used in two extra images (1991 and 1992) to test the models

Candanedo Guevara, Martin Edmundo

2001-07-01

220

Mapping shorelines to subpixel accuracy using Landsat imagery  

NASA Astrophysics Data System (ADS)

A promising method to accurately map the shoreline of oceans, lakes, reservoirs, and rivers is proposed and verified in this work. The method is applied to multispectral satellite imagery in two stages. The first stage is a classification of each image pixel into land/water categories using the conventional 'dark pixel' method. The approach presented here, makes use of a single shortwave IR image band (SWIR), if available. It is well known that SWIR has the least water leaving radiance and relatively little sensitivity to water pollutants and suspended sediments. It is generally the darkest (over water) and most reliable single band for land-water discrimination. The boundary of the water cover map determined in stage 1 underestimates the water cover and often misses the true shoreline by a quantity up to one pixel. A more accurate shoreline would be obtained by connecting the center point of pixels with exactly 50-50 mix of water and land. Then, stage 2 finds the 50-50 mix points. According to the method proposed, image data is interpolated and up-sampled to ten times the original resolution. The local gradient in radiance is used to find the direction to the shore, thus searching along that path for the interpolated pixel closest to a 50-50 mix. Landsat images with 30m resolution, processed by this method, may thus provide the shoreline accurate to 3m. Compared to similar approaches available in the literature, the method proposed discriminates sub-pixels crossed by the shoreline by using a criteria based on the absolute value of radiance, rather than its gradient. Preliminary experimentation of the algorithm shows that 10m resolution accuracy is easily achieved and in some cases is often better than 5m. The proposed method can be used to study long term shoreline changes by exploiting the 30 years of archived world-wide coverage Landsat imagery. Landsat imagery is free and easily accessible for downloading. Some applications that exploit the Landsat dataset and the new method are discussed in the companion poster: "Case-studies of potential applications for highly resolved shorelines."

Abileah, Ron; Vignudelli, Stefano; Scozzari, Andrea

2013-04-01

221

Linear features determined from Landsat imagery in North Dakota  

USGS Publications Warehouse

The report consists of a map (scale 1:500,000) that shows the linear features determined from Landsat imagery in North Dakota. The linear features, sometimes called linear trends or lineaments, are not identified as to type or origin. Most probably represent fractures or fracture zones, which may affect the movement of water or other fluids through the rocks. The linear features are classified as to length--less than 30 miles, 30 to 200 miles, 200 to 500 miles, and more than 500 miles. (USGS)

Cooley, M. E.

1983-01-01

222

Linear features determined from Landsat imagery in Wyoming  

USGS Publications Warehouse

The report consists of a map (scale 1:500,000) that shows the linear features determined from Landsat imagery in Wyoming. The linear features, sometimes called linear trends or lineaments, are not identified as to type or origin. Most probably represent fractures or fracture zones, which may affect the movement of water or other fluids through the rocks. The linear features are classified as to length--less than 30 miles, 30 to 200 miles, 200 to 500 miles, and more than 500 miles. (USGS)

Cooley, M. E.

1983-01-01

223

Summary of the operational land imager focal plane array for the Landsat Data Continuity Mission  

Microsoft Academic Search

The Landsat missions are the longest continuous record of changes in the Earth's surface as seen from space. The next follow-on activity is the Landsat Data Continuity Mission (LDCM). The LDCM objective is to extend the ability to detect and quantitatively characterize changes on the global land surface at a scale where natural and man-made causes of change can be

Kirk A. Lindahl; William Burmester; Kevin Malone; Ronald J. Schrein; Ronda Irwin; Eric Donley; Sandra R. Collins

2011-01-01

224

A Landsat analysis of range conditions in the Botswana Kalahari drought  

Microsoft Academic Search

An analysis of the range conditions in the Botswana Kalahari during the 1980-1987 drought is presented. Landsat MSS data were verified both from the air and the ground. Three primary spectral vegetation types were revealed by comparing aerial photograph sites with MSS data in terms of the hues on Landsat color composite print data. The darkening rate of type 1

Susan Ringrose; Wilma Matheson

1991-01-01

225

Determining the rate of forest conversion in Mato Grosso, Brazil, using Landsat MSS and AVHRR data  

Microsoft Academic Search

AVHRR-LAC thermal data and Landsat MSS and TM spectral data were used to estimate the rate of forest clearing in Mato Grosso, Brazil, between 1981 and 1984. The Brazilian state was stratified into forest and non-forest. A list sampling procedure was used in the forest stratum to select Landsat MSS scenes for processing based on estimates of fire activity in

Ross Nelson; Ned Horning; Thomas A. Stone

1987-01-01

226

Preparation of a 1:25000 Landsat map for assessment of burnt area on Etajima Island  

Microsoft Academic Search

The Etajima fire of 1978 in Japan was used to assess the accuracy of a method of classification, mapping and area estimation of the devastation caused by forest fire using Landsat MSS data. The classification and mapping method developed was limited to field sizes of about 10 km × 10 km, and the registration of Landsat data for mapping was

S. Tanaka; H. Kimura; Y. Suga

1983-01-01

227

Augmenting LANDSAT MSS Data with Topographic Information for Enhanced Registration And Classification  

Microsoft Academic Search

This paper deals with problems arising in the classification of LANDSAT MSS data from rugged terrain. A digital terrain model (DTM) was found to be useful in several ways. For registration by cross-correlation, mountain ridges were extracted from both a synthetic image based on the DTM and a LANDSAT image. Information from the DTM, from thematic maps, and meteorological data

Klaus Seidel; Frank Ade; Juerg Lichtenegger

1983-01-01

228

Registration of a LANDSAT Image to DTM (Digital Terrain Matrix) - An Error Analysis.  

National Technical Information Service (NTIS)

A mathematical model is postulated and tested that will enable a user to relate a digital LANDSAT image to a digital terrain matrix (DTM). The practicality of the procedure is examined and evaluated. One reason for registering a Landsat digital image to a...

M. A. Crombie J. A. Shine W. Moore G. Allton

1984-01-01

229

Absolute calibration of the Landsat Thematic Mapper using the Internal Calibrator  

Microsoft Academic Search

In order to assess the accuracy and usefulness of the Internal Calibrator of the Landsat 4 and 5 Thematic Mappers and characterize the radiometric calibration of the instruments themselves, several hundred scenes were extracted from the Landsat TM archive at the EROS Data Center, Sioux Falls, South Dakota. These scenes formed the basis of the TM Calibration Archive System and

Dennis Helder; W. Boucyk; Ron Morfitt

1998-01-01

230

Time-series analysis of rainforest clearing in Sabah, Borneo using Landsat imagery  

Microsoft Academic Search

T ropical forests are being cleared at alarming rates. The release of the Landsat image archive represents an opportunity to assess rainforest clearing over time through time-series analysis. The objective was to map the extent of rainforest clearing and assess land cover trends at the object level within a selected study area in Sabah, Borneo using Landsat images from 1991,

Kasper Johansen

2011-01-01

231

Continuous fields of land cover for the conterminous United States using Landsat data: First results from the Web-Enabled Landsat Data (WELD) project  

USGS Publications Warehouse

Vegetation Continuous Field (VCF) layers of 30 m percent tree cover, bare ground, other vegetation and probability of water were derived for the conterminous United States (CONUS) using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data sets from theWeb-Enabled Landsat Data (WELD) project. Turnkey approaches to land cover characterization were enabled due to the systematic WELD Landsat processing, including conversion of digital numbers to calibrated top of atmosphere reflectance and brightness temperature, cloud masking, reprojection into a continental map projection and temporal compositing. Annual, seasonal and monthly WELD composites for 2008 were used as spectral inputs to a bagged regression and classification tree procedure using a large training data set derived from very high spatial resolution imagery and available ancillary data. The results illustrate the ability to performLandsat land cover characterizations at continental scales that ar einternally consistent while retaining local spatial and thematic detail. ?? 2011 Taylor & Francis.

Hansen, M. C.; Egorov, A.; Roy, D. P.; Potapov, P.; Ju, J.; Turubanova, S.; Kommareddy, I.; Loveland, T. R.

2011-01-01

232

Evaluation of Areas Prepared for Planting Using Landsat Data Avaliacao de Areas Preparadas Para Plantio (Solonu) Utilizando Dados Do Satelite Landsat.  

National Technical Information Service (NTIS)

Three different algorithms (SINGLE-CELL, MAXVER and MEDIA K) were used to automatically interpret data from LANDSAT observations of an area of Ribeirao Preto, Brazil. Photographic transparencies were obtained, projected and visually interpreted. The resul...

N. D. J. Parada G. V. Deassuncao V. Duarte

1983-01-01

233

Influencia de Parametros Culturais de Cafezais Sobre OS Dados TM/LANDSAT-5 (Effect of Coffee Plantation Cultural Variables on LANDSAT-5/TM).  

National Technical Information Service (NTIS)

Coffee fields are very complex at a remote sensing satellite view. The objective was to understand this complexity. To do that, TM LANDSAT-5 digital images and ground truth data were obtained nearly simultaneously. Digital data were transformed to reflect...

L. Leonardi

1990-01-01

234

An Investigation of Vegetation and Other Earth Resource/Feature Parameters Using Landsat and Other Remote Sensing Data. 1: Landsat. 2: Remote Sensing of Volcanic Emissions.  

National Technical Information Service (NTIS)

A fanning technique based on a simplistic physical model provided a classification algorithm for mixture landscapes. Results of applications to LANDSAT inventory of 1.5 million acres of forest land in Northern Maine are presented. Signatures for potential...

R. W. Birnie R. E. Stoiber

1981-01-01

235

Modeling the dynamical interaction between epidemics on overlay networks  

NASA Astrophysics Data System (ADS)

Epidemics seldom occur as isolated phenomena. Typically, two or more viral agents spread within the same host population and may interact dynamically with each other. We present a general model where two viral agents interact via an immunity mechanism as they propagate simultaneously on two networks connecting the same set of nodes. By exploiting a correspondence between the propagation dynamics and a dynamical process performing progressive network generation, we develop an analytical approach that accurately captures the dynamical interaction between epidemics on overlay networks. The formalism allows for overlay networks with arbitrary joint degree distribution and overlap. To illustrate the versatility of our approach, we consider a hypothetical delayed intervention scenario in which an immunizing agent is disseminated in a host population to hinder the propagation of an undesirable agent (e.g., the spread of preventive information in the context of an emerging infectious disease).

Marceau, Vincent; Noël, Pierre-André; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

2011-08-01

236

On-demand Overlay Networks for Large Scientific Data Transfers  

SciTech Connect

Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.

Ramakrishnan, Lavanya; Guok, Chin; Jackson, Keith; Kissel, Ezra; Swany, D. Martin; Agarwal, Deborah

2009-10-12

237

Indium tin oxide overlayered waveguides for sensor applications  

NASA Astrophysics Data System (ADS)

The use of indium tin oxide (ITO) thin films as electrodes for integrated optical electrochemical sensor devices is discussed. The effect of various thicknesses of ITO overlayers exhibiting low resistivity and high transparency on potassium ion-exchanged waveguides fabricated in glass substrates is investigated over the wavelength range 500 900 nm. ITO overlayers are formed by reactive thermal evaporation in oxygen, followed by annealing in air to a maximum temperature of 320 C. With air as the superstrate, losses in the waveguides were found to increase dramatically above 30-nm ITO thickness for TE polarization and above 50-nm thickness for TM. Losses were increased over the whole wavelength range for a superstrate index close to that of water. A one-dimensional, multilayer waveguide model is used in the interpretation of the experimental results.

Luff, B. Jonathan; Wilkinson, James S.; Perrone, Guido

1997-09-01

238

Daylighting design overlays for equidistant sun-path projections  

SciTech Connect

Projections of the Sun's daily and seasonal paths frequently are used to solve building design problems involving site obstructions and shading of fenestration. In the United States, equidistant projections are perhaps the most widely used (compared to other sunpath projections) because of the commercial availability of a complete set of sun-path diagrams for a range of useful latitudes. This paper describes the development of a set of overlays designed for use with sun-path projections to predict illumination on any building surface throughout the year for standard climatological conditions. Illumination is calculated for clear and overcast skies and for direct sunlight using algorithms recommended by the Commission Internationale de l'Eclairage (CIE). Values for illumination incident upon the surface, as well as transmitted through single and double glazing, can be calculated. Similar overlays for solar radiation are being developed.

Selkowitz, S.

1981-08-01

239

Use of SLC-Off Landsat Image Data for Monitoring Land Use/Land Cover Trends in West Africa.  

National Technical Information Service (NTIS)

Landsat 7 imagery is one of the pillars of an ongoing program to monitor and map land use and land cover trends across West Africa. The program has a continuing need for Landsat data. When the SLC-Off problem occurred on Landsat 7 in May 2003, basic quest...

G. Tappan M. Cushing

2004-01-01

240

Scene selection and the use of NASA's global orthorectified Landsat dataset for land cover and land use change monitoring  

Microsoft Academic Search

This study examines the utility of NASA's circa 1990 and circa 2000 global orthorectified Landsat dataset for land cover and land use change mapping and monitoring across Africa. This is achieved by comparing the temporal and spatial variation of NDVI, measured independently by the NOAA-AVHRR at the time of Landsat scene acquisition, against the seasonal mean for each Landsat scene

Andrew J. Tatem; Anjali Nayar; Simon I. Hay

2006-01-01

241

From need to product: a methodology for completing a land cover map of Canada with Landsat data  

Microsoft Academic Search

Despite its very large territory and the best Landsat archive in the world, Canada has made very limited use of Landsat data for land cover mapping. The primary difficulty has been the prohibitive cost of information extraction and the earlier (and now overcome for Landsat-7 enhanced thematic mapper plus data) high cost of data purchase. The solution to this remaining

J. Cihlar; B. Guindon; J. Beaubien; R. Latifovic; D. Peddle; M. Wulder; R. Fernandes; J. Kerr

2003-01-01

242

Advancements of diffraction-based overlay metrology for double patterning  

NASA Astrophysics Data System (ADS)

As the dimensions of integrated circuit continue to shrink, diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges. Previously data of high accuracy and high precision were reported for litho-etch-litho-etch double patterning (DP) process using normal incidence spectroscopic reflectometry on specially designed targets composed of 1D gratings in x and y directions. Two measurement methods, empirical algorithm (eDBO) using four pads per direction (2x4 target) and modeling based algorithm (mDBO) using two pads per direction (2x2 target) were performed. In this work, we apply DBO techniques to measure overlay errors for a different DP process, litho-freeze-litho-etch process. We explore the possibility of further reducing number of pads in a DBO target using mDBO. For standard targets composed of 1D gratings, we reported results for eDBO 2x4 targets, mDBO 2x2 targets, and mDBO 2x1 target. The results of all three types of targets are comparable in terms of accuracy, dynamic precision, and TIS. TMU (not including tool matching) is less than 0.1nm. In addition, we investigated the possibility of measuring overlay with one single pad that contains 2D gratings. We achieved good correlation to blossom measurements. TMU (not including tool matching) is ~ 0.2nm. To our best knowledge, this is the first time that DBO results are reported on a single pad. eDBO allows quick recipe setup but takes more space and measurement time. Although mDBO needs details of optical properties and modeling, it offers smaller total target size and much faster throughput, which is important in high volume manufacturing environment.

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Weher, Ulrich; Volkman, Catherine; Mazur, Martin; Hu, Jiangtao

2011-03-01

243

Texture overlay onto deformable surface for virtual clothing  

Microsoft Academic Search

In this article, we describe a method for overlaying arbitrary texture image onto surface of T-shirt worn by a user. In this method, the texture image is previously divided into a number of patches. On the T-shirt, markers are printed at the positions corresponding to the vertices of the patches. The markers on the surface of the T-shirt are tracked

Jun Ehara; Hideo Saito

2005-01-01

244

Network Programmability for VPN Overlay Construction and Bandwidth Management  

Microsoft Academic Search

Reliability and security concerns have increased demand for Virtual Private Networks (VPNs). Ideally, a VPN service should\\u000a offer autonomous overlay networks with guaranteed bandwidth allocations over a shared network. Network providers seek an automated\\u000a VPN creation and management process, while users of a VPN would greatly benefit from secure control over the handling of their\\u000a traffic. Currently, network infrastructure does

Bushar Yousef; Doan B. Hoang; Glynn Rogers

2004-01-01

245

Topologically-Aware Overlay Construction and Server Selection  

Microsoft Academic Search

A number of large-scale distributed Internet applications could potentially benefit from some level of knowledge about the relative proximity between its participating host nodes. For example, the perfor- mance of large overlay networks could be improved if the application-level connectivity between the nodes in these networks is congruent with the un- derlying IP-level topology. Similarly, in the case of replicated

Sylvia Ratnasamy; Mark Handley; Richard M. Karp; Scott Shenker

2002-01-01

246

Ranking factors in peer-to-peer overlay networks  

Microsoft Academic Search

A large number of peer processes are distributed in a peer-to-peer (P2P) overlay network. It is difficult, maybe impossible for a peer to perceive the membership and location of every resource object due to the scalability and openness of a P2P network. In this article, we discuss a fully distributed P2P system where there is no centralized controller. Each peer

Kenichi Watanabe; Yoshio Nakajima; Tomoya Enokido; Makoto Takizawa

2007-01-01

247

Skewness and Kurtosis Risks of Quality Control in Overlay Inspection  

Microsoft Academic Search

The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer's risk and producer's risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of

Takashi Sato; Takahiro Ikeda; Kentaro Kasa; Masafumi Asano; Yasuharu Sato

2010-01-01

248

Are Virtualized Overlay Networks Too Much of a Good Thing?  

Microsoft Academic Search

Themajorityofrecenthigh-proflleworkinpeer-to-peernet- workshasapproachedtheproblemoflocationbyabstractingoverobject lookup services. Namespace virtualization in the overlay layer provides load balance andprovableboundsonlatency at lowcosts. We contend that namespace virtualization comes at a signiflcant cost for applications that naturally describe their data sets in a hierarchical manner.Opportunitiesforenhancingbrowsing,prefetchingande-cient attribute-based searches are lost. A hierarchy exposes relationships be- tween items near to each other in the topology; virtualization of the namespace

Peter J. Keleher; Bobby Bhattacharjee; Bujor D. Silaghi

2002-01-01

249

Network-Aware Overlay Multicast for Large Data Dissemination  

NASA Astrophysics Data System (ADS)

In this paper, we propose a network-aware overlay multicast (NAOM) technique for large data dissemination in a well-managed overlay network. To improve the throughput, NAOM utilizes forward-only hosts; these hosts participate in the overlay network but are not members of the multicast. With the inclusion of the forward-only hosts, data slices can detour bottleneck links and more resources can be used to build efficient multicast trees. Large data are divided into fixed-size slices, and the slices are delivered simultaneously to multicast receivers along the multiple multicast trees. We model the problem of building efficient multicast trees with the inclusion of forward-only hosts. The problem is an NP-hard problem, and we introduce a polynomial time heuristic algorithm. Furthermore, we propose a dynamic scheduling scheme for the transfer of data along the evaluated multicast trees. Our experimental results in a real network environment show an improvement of the throughput but at the cost of additional resource consumption of forward-only nodes.

Lee, Joonbok; Chon, Kilnam

250

Early radiometric performance assessment of the Landsat-8 Operational Land Imager (OLI)  

NASA Astrophysics Data System (ADS)

Landsat-8, the latest in the Landsat series of satellites, was launched on February 11, 2013 and carries on board the Operational Land Imager (OLI) as one of its payloads. The satellite's mission is to continue the long history of moderate resolution imaging of the Landsat program. The OLI follows the highly successful Landsat-5 and Landsat-7 in continuing to populate a global archive of Earth images that dates back to 1972. The design of the Landsat-8 instruments is a significant departure from earlier Landsats. The OLI is a pushbroom instrument; all previous recent Landsat instruments were electromechanical (whiskbroom) instruments. OLI also has two new spectral bands and refined bandpasses; the thermal imaging capability on Landsat-8 is in a separate instrument. The pushbroom design provides significantly better signal to noise performance than historically available, but at the expense of circa 70,000 detectors versus the 100 or so on previous instruments. The large focal plane and large number of detectors makes detector to detector relative calibration more challenging, increasing the propensity for banding and striping in imagery. On-board radiometric calibration devices include a shutter to measure the dark levels, a full aperture solar panel for calibration against the sun, and multiple sets of lamps for short-term stability monitoring. Early results from the on-board calibration devices indicate that the OLI is outperforming the Landsat-7 instrument in signal-to-noise ratio by an order of magnitude, consistent with pre-launch measurements. Over the first five months, the instrument is stable to within 0.7%, as measured by the lamps and solar diffuser. A relative calibration (detector-to-detector) and a linearization parameter update have been performed that reduce visible striping; with this update, the residual striping has been reduced by half in all OLI bands.

Barsi, Julia A.; Markham, Brian L.

2013-09-01

251

A Yukon River Basin Landsat Mosaic for Assessing Environmental Change  

NASA Astrophysics Data System (ADS)

Landsat data from the Global Land Survey (GLS) dataset for year 2000 was mosaicked to form a Yukon River Basin image map that is referenced to a geodetic base. It was produced from 66 Landsat-7 Enhanced Thematic Mapper Plus (ETM+) images collected from 1999-2002. Two products were created: (1) a geographically referenced database containing all seven of the spectral bands for the individual scenes and (2) a 3-band (shortwave infrared, near-infrared, and green - 7,4,2) radiometrically normalized shaded relief image map using the U.S. Geological Survey National Elevation Dataset and Canadian Digital Elevation Data from Natural Resources Canada. The science data product will facilitate studies to map the extent of snow, ice and surface water at a basin-wide scale. Focused studies on snow/ice transitions for selected glaciers will be conducted in order to establish accumulation ratios for use in future monitoring. The mosaic also shows the complex patterns of wildfires in the interior forests and the diversity of ecosystems throughout the basin. The shaded relief product image mosaic is a reference map for reconnaissance studies as well as a geographic framework within which to spatially integrate project-wide data and information.

Bouchard, M. A.; Dwyer, J. L.; Granneman, B.

2009-12-01

252

Study of the Nevada Test Site using Landsat satellite imagery  

SciTech Connect

In the period covered by the purchase order CSIS has obtained one Landsat image and determined that two images previously supplied to the principal investigator under a subcontract with George Washington University were inherently defective. We have negotiated with EOSAT over the reprocessing of those scenes and anticipate final delivery within the next few weeks. A critical early purchase during the subcontract period was of an EXABYTE tape drive, Adaptec SCSI interface, and the appropriate software with which to read Landsat images at CSIS. This gives us the capability of reading and manipulating imagery in house without reliance on outside services which have not proven satisfactory. In addition to obtaining imagery for the study, we have also performed considerable analytic work on the newly and previously purchased images. A technique developed under an earlier subcontract for identifying underground nuclear tests at Pahute Mesa has been significantly refined, and similar techniques were applied to the summit of Rainier Mesa and to the Yucca Flats area. An entirely new technique for enhancing the spectral signatures of different regions of NTS was recently developed, and appears to have great promise of success.

Zimmerman, P.D. [Georgetown Univ., Washington, DC (United States). Center for Strategic and International Studies

1993-07-01

253

Lithologic mapping using geobotanical and Landsat Thematic Mapper Data  

SciTech Connect

Detailed work has been undertaken to study the correlations among Landsat TM spectral data, lithologic units, geobotanical forest associations, and geomorphic site parameters in the predominantly deciduous forest of the Valley and Ridge province, Pennsylvania. The TM spectral data are taken from the November 2, 1982, overpass at a time when some of the study area was undergoing fall senescence. The forest association data are based on over 250 1/10-acre surveys. The lithologies are primarily two clastic sedimentary units, sandstone and shales, each with a different geomorphic slope and aspect. Both the TM and forest association data can be divided into four groups representing unique lithologic and geomorphic site parameters. The first principal component of the TM data separates the four lithologic/geomorphic units on the basis of their associated botanical and geomorphic site parameters. The second and third principal components contain information about forest density and canopy closure. It is apparent from this study that geobotanical forest associations are useful as indicators of lithology, and that changes in these forest associations are detectable with Landsat TM data from space.

Birnie, R.W.; Defeo, N.

1987-05-01

254

Evaluation of Free-Riding Traffic Problem in Overlay Routing and Its Mitigation Method  

NASA Astrophysics Data System (ADS)

Recent research on overlay networks has revealed that user-perceived network performance could be improved by an overlay routing mechanism. The effectiveness of overlay routing is mainly a result of the policy mismatch between the overlay routing and the underlay IP routing operated by ISPs. However, this policy mismatch causes a “free-riding” traffic problem, which may become harmful to the cost structure of Internet Service Providers. In the present paper, we define the free-riding problem in the overlay routing and evaluate the degree of free-riding traffic to reveal the effect of the problem on ISPs. We introduce a numerical metric to evaluate the degree of the free-riding problem and confirm that most multihop overlay paths that have better performance than the direct path brings the free-riding problem. We also discuss the guidelines for selecting paths that are more effective than the direct path and that mitigate the free-riding problem.

Hasegawa, Go; Hiraoka, Yuichiro; Murata, Masayuki

255

A Cross-Transmission Protocol Architecture Concept for Resource Discovery in P2P Overlay Networks  

Microsoft Academic Search

In this paper, we propose a cross-transmission protocol architecture for resource discovery in P2P overlay networks, where each client in the network can query and get the resource identifiers for other P2P overlay networks (like Infohash in Bittorrent network, AICH Top Hash in Emule\\/Edonkey network). In this way, client can download files from multi-overlay P2P networks simultaneously rather than from

Yi-Fang Qin; Xu Zhou; Hui Tang

2009-01-01

256

Defending P2Ps from Overlay Flooding-based DDoS  

Microsoft Academic Search

A flooding-based search mechanism is often used in un- structured P2P systems. Although a flooding-based search mechanism is simple and easy to implement, it is vulnerable to overlay distributed denial-of-service (DDoS) attacks. Most pre- vious security techniques protect networks from network-layer DDoS attacks, but cannot be applied to overlay DDoS attacks. Overlay flooding-based DDoS attacks can be more damaging in

Yunhao Liu; Xiaomei Liu; Chen Wang; Li Xiao

2007-01-01

257

OverDoSe: A Generic DDoS Protection Service Using an Overlay Network  

Microsoft Academic Search

We present the design and implementation of OverDoSe, an overlay network offering generic DDoS protection for targeted sites. OverDoSe clients and servers are isolated at the IP level. Overlay nodes route packets between a client and a server, and regulate traffic according to the server's instructions. Through the use of light-weight sec urity primitives, OverDoSe achieves resilience against compromised overlay

Elaine Shi; Ion Stoica; David Andersen; Adrian Perrig

258

Infrared differential interference contrast microscopy for 3D interconnect overlay metrology.  

PubMed

One of the main challenges for 3D interconnect metrology of bonded wafers is measuring through opaque silicon wafers using conventional optical microscopy. We demonstrate here the use infrared microscopy, enhanced by implementing the differential interference contrast (DIC) technique, to measure the wafer bonding overlay. A pair of two dimensional symmetric overlay marks were processed at both the front and back sides of thinned wafers to evaluate the bonding overlay. A self-developed analysis algorithm and theoretical fitting model was used to map the overlay error between the bonded wafers and the interconnect structures. The measurement accuracy was found to be better than 1.0 micron. PMID:23938801

Ku, Yi-Sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung

2013-08-12

259

Territorial analysis by fusion of LANDSAT and SAR data  

NASA Astrophysics Data System (ADS)

A highly informative content makes visible and infrared images the most used remotely sensed data (generally speaking) in earth resource and environmental analysis. On the other hand, sensitivity to surface roughness, water content, and independence of weather conditions and sunlight are the features that justify the growing interest and use of microwave radar data. The previous considerations clearly indicate data fusion as a key point for remote-sensing image classification. In this paper, a knowledge-based system to exploit such numerous and diverse sources of information is proposed. The authors started with the problem of fusing Landsat- MSS and Seasat-SAR images for terrain classification in order to increase the reliability of results with respect to single-sensor analysis. A new approach to the fusion of 2-D images, called the 'region overlapping' technique, is employed, and its advantages for terrain classification are shown. Experimental results are presented and discussed to show the interest of the approach.

Vernazza, Gianni L.; Dambra, Carlo; Parizzi, Francesco; Roli, Fabio; Serpico, Sebastiano B.

1991-09-01

260

Blending Science and Art with Landsat (Lena River Delta Lithograph)  

NSDL National Science Digital Library

This lithograph of the Lena River Delta is part of a collection of images of the Earth from space called, Landsat: Earth as Art. The images are designed to capture the attention of people who might not otherwise be interested in remote sensing. The images link the disciplines of science and art, and can be used to teach how the creative aspects of those disciplines employ similar human skills. The lithograph aims to help parents investigate the images with children ages 7-10. It encourages children and their parents to recognize patterns made in the surface of the Earth and is designed to help them see the inherent beauty of the Earth from space.

2006-08-01

261

Bandwidth auction for SVC streaming in dynamic multi-overlay  

NASA Astrophysics Data System (ADS)

In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

Xiong, Yanting; Zou, Junni; Xiong, Hongkai

2010-07-01

262

Land Surface Albedo of Large Urban Agglomerations from Landsat Observations  

NASA Astrophysics Data System (ADS)

The world's urban population is expected to rise to 5 billion by the year 2030 and urban climates are expected to have a growing influence on surface energy budgets at regional-to-global scales. A key component of surface energy balance is shortwave reflectivity or albedo, which can be measured and modeled with optical satellite imagery such as Landsat. In this study, we processed Landsat ETM+ imagery of world's 20 largest urban areas as of the early 2000s. To derive robust albedo estimates for each urban area, we applied an atmospheric correction and BRDF modeling using the 6s atmospheric radiative transfer model as well as an empirically based narrow-to-broadband conversion involving ETM+ bands 2, 4, and 7. A spatial analysis of the resultant albedo images was performed using various statistical and geostatistical methods. The results reveal moderate variability of land-surface albedo values among the various urban areas with mean values for urban land surfaces ranging between 0.12 for Cairo to 0.23 for Buenos Aires. As expected, in most instances we found that the albedo of these large urban areas was less than what we observed for nearby non-urban land cover types. The absolute differences in albedo between urban areas and adjacent non-urban areas within each ETM+ scene ranged from large (0.21 for Cairo) to very small (0.02 for Shanghai). Our preliminary conclusion is that the albedo difference (or the "urban albedo effect") between urban and adjacent non-urban land surfaces was greater for cities situated in arid environments than "green" cities that are situated in mesic, temperate regions.

Fuller, D. O.; Roy, S. S.; Cohen, A.

2006-05-01

263

Classification of forest growth stage using Landsat TM data  

NASA Astrophysics Data System (ADS)

This study examined the utility of polytomous logistic regression in pixel classification of remotely sensed images by the growth stage of forests. For a population of grouped continuous categories, the assumption of normal distribution of independent variables, which is often required in multivariate classification methods, may not be appropriate. Two types of polytomous logistic regression procedures, multinomial and cumulative logistic regression, were used to classify Landsat TM data by growth stage (regeneration-immature, intermediate, and mature) of loblolly pine (Pinus taeda L.) forest in the east central Mississippi. Multinomial logistic regression is typically used for analysis of unordered categorical data. Cumulative logistic regression is one of the most commonly used methods of ordinal logistic regression which is generally preferred to analyze ordered categorical data, although, it imposes restrictions on the data. Three hundred sample points were located randomly throughout the study site and vectors of pixel values of four bands of Landsat TM data were used to predict growth stage at each sample location. The results were compared to that of parametric and nonparametric discriminant analysis, k-nearest neighbor method. Non-normal distribution of independent variables indicated a violation of the assumptions for parametric discriminant analysis. Classification with cumulative logistic regression using four bands was performed first. However, the assumption of the model was not met. So, the classification was also performed using only band 4 which appeared to meet the assumption. The error rate of cumulative logistic regression was 39.12% with all the bands and 37.70% with band 4 alone. Although error rate with cumulative logistic regression with band 4 alone resulted in the lowest error rate, the improvement over other methods was marginal. The error rate of k-nearest neighbor method varied from 38.68 to 48.06% depending on choice of the value of k.

Fujisaki, Ikuko; Gerard, Patrick D.; Evans, David L.

2005-09-01

264

Over-water atmospheric correction for Landsat's new OLI sensor  

NASA Astrophysics Data System (ADS)

The Operational Land Imager (OLI) is a new sensor being developed by the joint USGS-NASA Landsat Data Continuity Mission that exhibits an exciting potential to be used for monitoring Case 2 waters. With upgrades such as a Coastal Aerosol band, 12 bit quantization, and improved signal-to-noise, preliminary studies indicate that OLI should be radiometrically superior to its predecessors. Considering that OLI will have the traditional 30m resolution of other Landsat instruments, and that its data is free to the community, this sensor should be an invaluable tool for long-term monitoring of water quality in Case 2 waters, especially in the nearshore environment. Through the use of simulated data, previous research indicates that OLI can retrieve the levels of three main water quality indicators (chlorophyll, suspended materials, and colored-dissolved organic matter (CDOM)) to within 7% of their expected range when atmospheric effects are ignored. Since the atmosphere typically represents a major source of error when quantifying water constituents from space, significant efforts have been made to develop techniques that will accurately remove atmospheric effects from OLI data. As OLI is an instrument designed for land-based studies, it will not be equipped with the appropriate bands required by traditional water-based atmospheric correction algorithms. This work presents a new atmospheric correction technique that was developed specifically for the OLI instrument. Preliminary results indicate that when atmospheric effects are included, OLI can retrieve the levels of the three water parameters to within 15% of their expected range, which is within the desired error range for this type of research.

Gerace, Aaron D.; Schott, John R.

2012-05-01

265

Web-enabled Landsat Data (WELD): a Consistent Seamless Near Real Time MODIS-Landsat Data Fusion for the Terrestrial User Community  

NASA Astrophysics Data System (ADS)

The overall objective of NASA's Making Earth System Data Records for Use in Research Environments (MEaSUREs) solicitations is to select projects providing Earth science data products and services driven by NASA's Earth science goals and contributing to advancing NASA's "missions to measurements" concept. This project contributes to the Land measurement theme; working at high spatial resolution and using state of the art and validated MODIS land products to systematically generate "seamless" radiometrically consistent mosaiced Landsat ETM+ data sets with per-pixel quality assessment information and derived land cover characterization at monthly, seasonal and annual time periods. The project will improve the consistency and quality of ETM+ SLC-off data through a fusion with MODIS land products, including the MODIS BRDF anisotropy product to radiometrically normalize and fill missing (cloudy and SLC-off) Landsat pixels, the MODIS atmospheric characterization data and procedure to systematically atmospherically correct the Landsat data, and the MODIS vegetation continuous field product to provide training for Landsat scale land cover characterization. The resulting high spatial resolution Landsat mosaic products will be generated for the conterminous USA (CONUS) and Alaska for a 7 year period, and made freely available to the user community via the Internet. Early CONUS results, algorithm insights, and information on how to access sample data products, and steps for community outreach and participation are presented.

Roy, D.; Ju, J.; Vermote, E.; Kline, K.; Loveland, T.; Hansen, M.

2008-12-01

266

Hydrogeological Evaluation of Qatar Peninsula Using LANDSAT Imagery and Geophysical Data.  

National Technical Information Service (NTIS)

The application of image processing techniques to landsat satellite images proved to be of major significance in the evaluation of the hydrogeological situation in Qatar peninsula. The images are correlatable with the geophysical resistivity maps of the p...

M. A. Yehia I. E. Harhash

1982-01-01

267

Location of Kimberlites Using Landsat Thematic Mapper Images and Aerial Photographs: The Redondao Diatreme, Brazil.  

National Technical Information Service (NTIS)

LANDSAT Thematic Mapper images and aerial photographs were used in the detection of kimberlite derived materials in the Redondao test site. In this area, kimberlite derived soils show a flora constituted mainly by grasses and shrubs, which differ from the...

R. Almeida-filho R. M. G. Castelobranco

1991-01-01

268

Interpreting the Geology of Glen Coe Using LANDSAT MSS Data and Aerial Photographs.  

National Technical Information Service (NTIS)

The area around Glen Coe in Scotland was surveyed using LANDSAT MSS and aerial photography. The area exhibits a number of obvious structural features and lithologic units and, even in the presence of considerable vegetation cover and surficial deposits, m...

G. A. A. Abdelhamid R. A. Vaughan

1988-01-01

269

Design Study of TDRS Antenna Gimbal System for Landsat-D.  

National Technical Information Service (NTIS)

The conceptual design studies of a two axis antenna drive assembly for the TDRSS link communications subsystem for LANDSAT D are presented. The recommended antenna drive assembly is a simple and reliable design substantially similar to the antenna and sol...

J. Wu

1977-01-01

270

Application of LANDSAT TM Images to Assess Circulation and Dispersion in Coastal Lagoons.  

National Technical Information Service (NTIS)

The main objectives are formulated around a four pronged work approach, consisting of tasks related to: image processing and analysis of LANDSAT thematic mapping; numerical modeling of circulation and dispersion; hydrographic and spectral radiation field ...

B. Kjerfve J. R. Jensen K. E. Magill

1986-01-01

271

Estimation of the Sugar Cane Cultivated Area from LANDSAT Images Using the Two Phase Sampling Method.  

National Technical Information Service (NTIS)

A two phase sampling method and the optimal sampling segment dimensions are developed for the estimation of the sugar cane cultivated area. This technique employs visual interpretations of LANDSAT images and panchromatic aerial photographs considered as t...

C. A. Cappelletti F. J. Mendonca D. C. L. Lee Y. E. Shimabukuro

1982-01-01

272

Application of Landsat Images to the Study of Level Soils for Recognizing Drainage Areas.  

National Technical Information Service (NTIS)

Photographic images from LANDSAT 1 were applied to the study of soil in Desaguadero, Bolivia, in order to locate areas with high agricultural and livestock potential. Photointerpretation techniques were emphasized and advantages of information obtained vi...

M. U. Espinoza

1977-01-01

273

Case Studies on the Geological Application of LANDSAT Imagery in Brazil.  

National Technical Information Service (NTIS)

The author has identified the following significant results. Sao Domingos Range, Pocos de Caldas, and Araguaia and Tocantins Rivers in Brazil were selected as test sites for LANDSAT imagery. The satellite images were analyzed using conventional photointer...

F. deMendonca A. Correa C. C. Liu

1975-01-01

274

Application of Multispectral Radar and Landsat Imagery to Geologic Mapping in Death Valley.  

National Technical Information Service (NTIS)

Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quatenary alluvial and evaporite deposits in Death Valley, California. Unprocessed r...

M. Daily C. Elachi T. Farr W. Stromberg S. Williams

1978-01-01

275

Applications of LANDSAT Thematic Mapper Imagery to the Study of Subtle Variations in Lithology.  

National Technical Information Service (NTIS)

Study of enhanced LANDSAT TM images of several localities in semi-arid to arid regions revealed subtle variations within lithologies the reasons for which were not directly evident in the field. Samples were collected during fieldwork, and laboratory spec...

A. Pontual

1988-01-01

276

Surgical navigation by autostereoscopic image overlay of integral videography.  

PubMed

This paper describes an autostereoscopic image overlay technique that is integrated into a surgical navigation system to superimpose a real three-dimensional (3-D) image onto the patient via a half-silvered mirror. The images are created by employing a modified version of integral videography (IV), which is an animated extension of integral photography. IV records and reproduces 3-D images using a microconvex lens array and flat display; it can display geometrically accurate 3-D autostereoscopic images and reproduce motion parallax without the need for special devices. The use of semitransparent display devices makes it appear that the 3-D image is inside the patient's body. This is the first report of applying an autostereoscopic display with an image overlay system in surgical navigation. Experiments demonstrated that the fast IV rendering technique and patient-image registration method produce an average registration accuracy of 1.13 mm. Experiments using a target in phantom agar showed that the system can guide a needle toward a target with an average error of 2.6 mm. Improvement in the quality of the IV display will make this system practical and its use will increase surgical accuracy and reduce invasiveness. PMID:15217256

Liao, Hongen; Hata, Nobuhiko; Nakajima, Susumu; Iwahara, Makoto; Sakuma, Ichiro; Dohi, Takeyoshi

2004-06-01

277

Active membrane masks for improved overlay performance in proximity lithography  

NASA Astrophysics Data System (ADS)

Membrane masks are thin (2 micron x 35 mm x 35 mm) structures that carry the master exposure patterns in proximity (X-ray) lithography. With the continuous drive to the printing of ever-finer features in microelectronics, the reduction of mask-wafer overlay positioning errors by passive rigid body positioning and passive stress control in the mask becomes impractical due to nano and sub-micron scale elastic deformations in the membrane mask. This paper describes the design, mechanics and performance of a system for actively stretching a membrane mask in-plane to control overlay distortion. The method uses thermoelectric heating/cooling elements placed on the mask perimeter. The thermoelectric elements cause controlled thermoelastic deformations in the supporting wafer, which in turn corrects distortions in the membrane mask. Silicon carbide masks are the focus of this study, but the method is believed to be applicable to other mask materials, such as diamond. Experimental and numerical results will be presented, as well as a discussion of the design issues and related design decisions.

Huston, Dryver R.; Plumpton, James; Esser, Brian; Sullivan, Gerald A.

2004-07-01

278

Application of Landsat imagery to regional-scale assessments of lake clarity  

Microsoft Academic Search

A procedure that uses Landsat imagery to estimate Secchi disk transparency (SDT) of lakes was developed and applied to ?500 lakes with surface areas >10ha in the seven-county metropolitan area of Minneapolis and St. Paul, MN, USA, to assess spatial patterns and temporal trends in lake clarity. Thirteen Landsat MSS and TM images over the period 1973–1998 were used for

Steven M. Kloiber; Patrick L. Brezonik; Marvin E. Bauer

2002-01-01

279

Green leaf phenology at Landsat resolution: Scaling from the field to the satellite  

Microsoft Academic Search

Despite the large number of in situ, plot-level phenological measurements and satellite-derived phenological studies, there has been little success to date in merging these records temporally or spatially. In this research, we bridge this scale gap through higher resolution satellite records (Landsat) and quantify the accuracy of satellite-derived metrics with direct field measurements. We compiled fifty-seven Landsat scenes from southern

Jeremy Isaac Fisher; John F. Mustard; Matthew A. Vadeboncoeur

2006-01-01

280

Comparison of Tasseled Cap-based Landsat data structures for use in forest disturbance detection  

Microsoft Academic Search

Landsat satellite data has become ubiquitous in regional-scale forest disturbance detection. The Tasseled Cap (TC) transformation for Landsat data has been used in several disturbance-mapping projects because of its ability to highlight relevant vegetation changes. We used an automated composite analysis procedure to test four multi-date variants of the TC transformation (called “data structures” here) in their ability to facilitate

Sean P. Healey; Warren B. Cohen; Yang Zhiqiang; Olga N. Krankina

2005-01-01

281

Landsat 7 Data Sets: LAN files for use with MultiSpec  

NSDL National Science Digital Library

This site provides a number of Landsat 7 scene subsets as LAN files that are intended for use with Purdue University's MultiSpec software. Users also have the option of downloading the Landsat images as TIFF files in four different band combinations. Links are included to download Multi-Spec, a MultiSpec tutorial, and an introduction to remote-sensing PowerPoint presentation with detailed notes.

2011-02-28

282

Using Landsat data to determine land use changes in Datong basin, China  

Microsoft Academic Search

The aim of this study was to determine land use changes in Datong basin using multitemporal Landsat data for the period of\\u000a 1977–2006. Four dates of Landsat images from 1977, 1990, 2000, and 2006 were selected to classify the study area. Based on\\u000a the supervised classification method of maximum likelihood algorithm, images were classified into six classes: water, urban,\\u000a forest,

Ziyong Sun; Rui Ma; Yanxin Wang

2009-01-01

283

Interpretation of a Landsat image of an unusual flood phenomenon in Australia  

USGS Publications Warehouse

A Landsat image of part of the flooded area of Cooper Creek, Queensland, Australia, in February 1974, shows large dark areas within the flooded valley. The dark areas are believed to be wet, but unflooded, areas of dark alluvial soil. These striking features, which have not previously been identified on Landsat images, must be properly interpreted so as not to confuse them with clear water. ?? 1978.

Robinove, C. J.

1978-01-01

284

Robotic weld overlay coatings for erosion control. Final technical progress report, July 1992--July 1995.  

National Technical Information Service (NTIS)

The erosion behavior of weld overlay coatings has been studied. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400(degrees)C at 90(degrees) and 30(degrees) particle impact angl...

B. F. Levin J. N. DuPont A. R. Marder

1995-01-01

285

Investigation of systematical overlay errors limiting litho process performance of thick implant resists  

Microsoft Academic Search

Tapered resist profiles have been found to cause a deterimental effect on the overlay measurement capability, affecting lithography processes which utilize thick implant resist. Particularly, for resist thicknesses greater than 1.5 mum, the systematical contribution to the overlay error becomes predominant. In CMOS manufacturing, these resist types are being used mainly for high energy well implants. As design rules progressively

Alexandra G. Grandpierre; Roberto Schiwon; Jens-. Bruch; Christoph Nacke; Uwe P. Schroeder

2004-01-01

286

Historical data learning based dynamic LSP routing for overlay IP over WDM networks  

Microsoft Academic Search

In overlay IP over WDM networks, there are only limited information exchanges between the two layers through the user network interface (UNI) [1] for service requests and responses. To enhance the overlay network performance while maintaining its simplicity, we propose for the first time to learn from the historical data of lightpath setting up costs maintained by the logical layer

Xiaojun Yu; Gaoxi Xiao; Tee-Hiang Cheng

2009-01-01

287

Towards a Common API for Structured Peer-to-Peer Overlays  

Microsoft Academic Search

In this paper, we describe an ongoing effort to define com- mon APIs for structured peer-to-peer overlays and the key abstractions that can be built on them. In doing so, we hope to facilitate independent innovation in overlay pro- tocols, services, and applications, to allow direct experi- mental comparisons, and to encourage application devel- opment by third parties. We provide

Frank Dabek; Ben Y. Zhao; Peter Druschel; John Kubiatowicz; Ion Stoica

2003-01-01

288

Optimal path-control for dual-frequency overlay GNSS receivers  

Microsoft Academic Search

This paper presents a general overlay based front- end architecture that enables the joint reception of two signals broadcast in separate frequency bands, sharing just one common baseband stage. The consequences of this overlay in terms of signal quality are analyzed and it is shown that the noise floor superposition results in non-negligible signal degradations. However, it is also demonstrated

Alexander Rugamer; Cecile Mongredian; Santiago Urquijo; Gunter Rohmer

2011-01-01

289

A quantitative comet assay: Imaging and analysis of virus plaques formed with a liquid overlay  

Microsoft Academic Search

Although the plaque assay defines a “gold-standard” for measuring virus infectivity, its reliance on plaque counting limits its sensitivity. When the assay is performed with a liquid overlay, instead of agar overlay, spontaneous flows can promote a uni-directional spread of infection, creating elongated regions of cytopathology that resemble comets. As a model system comet and plaque cultures of vesicular stomatitis

Ying Zhu; John Yin

2007-01-01

290

IQ-Paths: Predictably High Performance Data Streams across Dynamic Network Overlays  

Microsoft Academic Search

Overlay networks are a key vehicle for delivering network and processing resources to high performance applications. For shared networks, however, to consistently deliver such resources at desired levels of performance, overlays must be managed at runtime, based on the continuous assessment and prediction of available distributed resources. Data-intensive applications, for example, must assess, predict, and judiciously use available network paths,

Zhongtang Cai; Vibhore Kumar; Karsten Schwan

2006-01-01

291

Metrology tool fleet management: applying FMP tool matching and monitoring concepts to an overlay fleet  

NASA Astrophysics Data System (ADS)

Overlay tool matching and accuracy issues are quickly reaching a comparable complexity to that of critical dimensional metrology. While both issues warrant serious investigation, this paper deals with the matching issues associated with overlay tools. Overlay tools need to run and measure as if they are a single tool - they need to act as one. In this paper a matching methodology is used to assess a set of overlay tools in a multiple of overlay applications. The methodology proposed in a prior2 SPIE paper is applied here to a fleet of two generations of overlay tools to detect measurement problems not seen with convention Statistical Process Control techniques. Four studies were used to examine the benefits of this matching methodology for this fleet of overlay tools. The first study was a matching assessment study. The second study was a hardware comparison between generations of tools. The third study was a measurement strategy comparison. The final study was a long term matching exercise where one example of a traditional long term monitoring strategy was compared to a new long term monitoring strategy. It is shown that this new tool matching method can be effectively applied to overlay metrology.

Morningstar, Jennifer; Solecky, Eric; Archie, Chas; Banke, Bill

2006-04-01

292

Benchmarking of current generation overlay systems at the 130-nm technology node  

Microsoft Academic Search

The Overlay Metrology Advisory Group (OMAG) is a group comprised of technical experts in the field of optical metrology from International SEMATECH Member Companies and the National Institute of Standards and Technology (NIST). This council created a specification for overlay metrology benchmarking which indicates the critical parameters to be addressed in order to comply with the International Technology Roadmap for

Beth Russo; Michael Bishop

2003-01-01

293

Effect of PCC Joint Skew on Reflective Cracking in HMA Overlays  

Microsoft Academic Search

Reflective cracking is a relatively premature distress that occurs in HMA materials overlaying cracked and jointed underlying pavements. The high concentration of stresses and strains in the vicinity of the discontinuity of the old pavement causes the cracks to reflect into the newly placed HMA overlay. While it is a common practice to use skewed transverse joints in rigid pavements

Ziad G. Ghauch

2011-01-01

294

Minimization of total overlay errors on product wafers using an advanced optimization scheme  

Microsoft Academic Search

The matching of wafer steppers is accomplished typically by patterning two successive layers, using different steppers of interest for each layer, and measuring the overlay at many points in the exposure field. Matching is considered to be optimized when some metric, such the sum-of-squares of overlay errors, is minimized over all measured points within the field. This is to be

Harry J. Levinson; Moshe E. Preil; Patrick J. Lord

1997-01-01

295

Toward 7nm target on product overlay for C028 FDSOI technology  

NASA Astrophysics Data System (ADS)

The continuous need for lithography overlay performance improvement is a key point for advanced integrated circuit manufacturing. Overlay control is more and more challenging in the 2x nm process nodes regarding functionality margin of the chip and tool capability. Transistor architecture rules which are set, confirm poly to contact space as the most critical one for 28nm technology node. Critical Dimension variability of these layers, even with best in class process stability, in addition to design constraint lead to on product overlay specifications of around 7nm. In order to ensure that the target is met in production environment and to identify potential ways for improvement, identification of the contributors to overlay errors is essential. We have introduced a novel budget breakdown methodology using both bottom-up and top-down overlay data. For the bottom up part, we have performed extensive testing with very high sampling scheme so as to quantify the main effects. In-line overlay metrology data has been used for top down approach to verify the overall performance in production. In this paper we focused on the 28nm contact to gate overlay in a FDSOI process. The initial inconsistency between bottom up and top down results led us to further exploration of the root cause of these inconsistencies. We have been able to highlight key figures to focus on, like reticle heating, wafer table contamination and etch processing effects. Finally, we conclude on 7nm overlay target achievement feasibility in high volume manufacturing environment.

Gatefait, Maxime; Le-Gratiet, Bertrand; Goirand, Pierre Jerome; Lam, Auguste; Van Haren, Richard; Pastol, Anne; Doytcheva, Maya; Liu, Xing Lan; Beltman, Jan

2013-04-01

296

Simplified Solution for Periodic Thermal Discontinuities in Asphalt Overlays Bonded to Rigid Pavements  

Microsoft Academic Search

This work investigates the elastic fields which develop in an overlay bonded to a rigid substrate when the system is subjected to thermally induced stress. A two-dimensional solution of the displacement field is derived for periodic discontinuities distributed in a hot mix asphalt overlay bonded to a rigid pavement, where the length of the pavement before cracking develops is much

H. M. Yin; W. G. Buttlar

2007-01-01

297

Colored overlays enhance visual perceptual performance in children with autism spectrum disorders  

Microsoft Academic Search

Children with autism spectrum disorders (ASD), together with controls matched for age and ability participated in three experiments that assessed the therapeutic benefit of colored overlays. The findings from the first experiment showed that a significantly greater proportion of children with ASD, than controls, increased reading speed when using a colored overlay. This finding was replicated in the second experiment

A. K. Ludlow; A. J. Wilkins; P. Heaton

2008-01-01

298

Application of DBM system to overlay verification and wiggling quantification for advanced process  

NASA Astrophysics Data System (ADS)

With the shrinkage of semiconductor device scales, advanced semiconductor industries face tremendous challenges in process control. As lithography and etch processes are pushed to get smaller dimensions, the overlay and wiggling control are hot issues due to the limiting of pattern performance. Many chip makers are using Double Patterning Technology (DPT) process to overcome design rule limitations but they are also concerned about overlay control. In DPT process, obtaining accurate overlay data by measuring overlay marks with traditional metrology is difficult because of the difference of shape and position between cell pattern and overlay marks. Cell to overlay mark miss-match will occur when there is lens aberration or mask registration error. Therefore, the best way to obtain accurate overlay data without error is to measure the real cell itself. The overlay of the cell array using DPT process can be measured by analyzing the relative position of the 2nd exposed pattern to the 1st exposed pattern. But it is not easy to clearly distinguish a 1st layer and 2nd layer in a patterned cell array image using CD SEM. The Design Based Metrology (DBM)-system can help identify which cell pattern is a 1st or 2nd layer, so overlay error between the 1st and 2nd layers at DPT process can be checked clearly. Another noticeable problem in advanced processing is wiggling. The wiggling of a pattern become severe by the etch process and must be controlled to meet electrical characteristics of what the semiconductor device requires. The 1st stage of wiggling control is to understand the level of wiggling which is crucial to device performance. The DBM-system also can be used for quantification of wiggling by determining specially designed parameters. In this paper we introduce overlay verification and wiggling quantification through new methodology for advanced memory devices.

Lee, Taehyeong; Kim, Jungchan; Yoo, Gyun; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Park, Byoungjun; Maruyama, Kotaro; Yamamoto, Masahiro

2012-03-01

299

Comparison of outgassing models for the landsat thematic mapper sensors  

USGS Publications Warehouse

The Thematic Mapper (TM) is a multi-spectral electro-optical sensor featured onboard both the Landsat 4 (L4) and Landsat 5 (L5) satellites. TM sensors have seven spectral bands with center wavelengths of approximately 0.49, 0.56, 0.66, 0.83, 1.65, 11.5 and 2.21 ??m, respectively. The visible near-infrared (VNIR) bands are located on the primary focal plane (PFP), and two short-wave infrared (SWIR) bands and the thermal infrared (TIR) band are located on the cold focal plane (CFP). The CFP bands are maintained at cryogenic temperatures of about 91 K, to reduce thermal noise effects. Due to the cold temperature, an ice film accumulates on the CFP dewar window, which introduces oscillations in SWIR and an exponential decay in TIR band responses. This process is usually monitored and characterized by the detector responses to the internal calibrator (IC) lamps and the blackbody. The ice contamination on the dewar window is an effect of the sensor outgassing in a vacuum of the space environment. Outgassing models have been developed, which are based on the thin-film optical interference phenomenon. They provide the coefficients for correction for outgassing effects for the entire mission's lifetime. While the L4 TM ceased imaging in August 1993, the L5 TM continues to operate even after more than 23 years in orbit. The process of outgassing in L5 TM is still occurring, though at a much lower rate than during early years of mission. Although the L4 and L5 TM sensors are essentially identical, they exhibit slightly different responses to the outgassing effects. The work presented in the paper summarizes the results of modeling outgassing effects in each of the sensors and provides a detailed analysis of differences among the estimated modeling parameters. For both sensors, water ice was confirmed as a reasonable candidate for contaminant material, the contaminant growth rate was found to be gradually decreasing with the time since launch, and the indications exist that some film may remain after the CFP warm-up procedures, which are periodically initiated to remove accumulated contamination. The observed difference between the models could be contributed to differences in the operational history for the sensors, the content and amount of contaminant impurities, the sensor spectral filter responses, and the internal calibrator systems.

Micijevic, E.; Chander, G.

2007-01-01

300

BWR pipe crack and weld clad overlay studies  

SciTech Connect

Leaks and cracks in the heat-affected zones of weldments in austenitic stainless steel piping in boiling water reactors (BWRs) due to intergranular stress corrosion cracking (IGSCC) have been observed since the mid-1960s. Since that time, cracking has continued to occur, and indication have been found in all parts of the recirculation system, including the largest diameter lines. Proposed solutions for the problem include procedures that produce a more favorable residual stress state on the inner surface, materials that are more resistant to stress corrosion cracking (SCC), and changes in the reactor environment that decrease the susceptibility to cracking. In addition to the evaluation of these remedies, it is also important to gain a better understanding of the weld overlay procedure, which is the most widely used short-term repair for flawed piping.

Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Park, J.Y.; Ruther, W.E.

1984-10-01

301

Erosion studies on duplex and graded ceramic overlay coatings  

NASA Astrophysics Data System (ADS)

The solid-particle erosion resistance of ceramic thermal barrier coatings (TBCs) is of considerable economic and industrial significance. Of additional significance to the service performance of these coatings is the effort to minimize the differences in coefficients of thermal expansion between the metallic substrate and the overlay TBC. A new design strategy toward this effort is the introduction of functionally graded interlayers between the metallic and ceramic layers. This research examines the role of interlayer grading, microstructure, and thermal cycling on the solid-particle erosion behavior of partially stabilized zirconia and alumina coatings at ambient and elevated temperatures. The results point to beneficial effects of grading and processing on the elevated temperature erosion response of these deposits.

Usmani, Saifi; Sampath, Sanjay

1996-11-01

302

ECHO: a community video streaming system with interactive visual overlays  

NASA Astrophysics Data System (ADS)

We describe a networked video application where personalized avatars, controlled by a group of "hecklers", are overlaid on top of a real-time encoded video stream of an Internet game for multicast consumption. Rather than passively observing the streamed content individually, the interactivity of the controllable avatars, along with heckling voice exchange, engenders a sense of community during group viewing. We first describe how the system splits video into independent regions with and without avatars for processing in order to minimize complexity. Observing that the region with avatars is more delay-sensitive due to their interactivity, we then show that the regions can be logically packetized into separable sub-streams, and be transported and buffered with different delay requirements, so that the interactivity of the avatars can be maximized. The utility of our system extends beyond Internet game watching to general community streaming of live or pre-encoded video with visual overlays.

Cheung, Gene; Tan, Wai-tian; Shen, Bo; Ortega, Antonio

2008-01-01

303

Lipid adlayer organization mediated by a liquid overlayer.  

PubMed

We report on the formation of a chemically bound 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer on modified Au and silica surfaces, and changes in the organization of the interfacial lipid layer associated with immersion in aqueous solution. We have studied the interface using steady state and time resolved fluorescence spectroscopy, water contact angle and optical ellipsometry measurements, and electrochemical methods. Our data reveal that the DMPC adlayer in contact with air forms a relatively well organized interface that mediates the rotational motion of perylene. In the presence of an aqueous overlayer, perylene reorientation becomes more rapid, consistent with a reduction in the organization of the interfacial lipid adlayer. One implication of this finding is that the interfacial adlayer is less than a uniform monolayer, which is confirmed by electrochemical data. Our data underscore the importance of water in mediating the organization of interfacial lipid adlayers. PMID:22995467

Baumler, S M; Blanchard, G J

2012-08-31

304

Lipid adlayer organization mediated by a liquid overlayer  

NASA Astrophysics Data System (ADS)

We report on the formation of a chemically bound 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer on modified Au and silica surfaces, and changes in the organization of the interfacial lipid layer associated with immersion in aqueous solution. We have studied the interface using steady state and time resolved fluorescence spectroscopy, water contact angle and optical ellipsometry measurements, and electrochemical methods. Our data reveal that the DMPC adlayer in contact with air forms a relatively well organized interface that mediates the rotational motion of perylene. In the presence of an aqueous overlayer, perylene reorientation becomes more rapid, consistent with a reduction in the organization of the interfacial lipid adlayer. One implication of this finding is that the interfacial adlayer is less than a uniform monolayer, which is confirmed by electrochemical data. Our data underscore the importance of water in mediating the organization of interfacial lipid adlayers.

Baumler, S. M.; Blanchard, G. J.

2012-12-01

305

Skewness and Kurtosis Risks of Quality Control in Overlay Inspection  

NASA Astrophysics Data System (ADS)

The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer’s risk and producer’s risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of the small sample size. A new acceptance test by variables was introduced for a non-normal population. It included sample skewness and kurtosis as well as mean and standard deviations. Using operating characteristic (OC) curves, it was shown that sampling inspection by variables can be applied safely to a strong non-normal population with new variables.

Takashi Sato,; Takahiro Ikeda,; Kentaro Kasa,; Masafumi Asano,; Yasuharu Sato,

2010-06-01

306

Patterning of Heteroepitaxial Overlayers from Nano to Micron Scales  

NASA Astrophysics Data System (ADS)

Thin heteroepitaxial overlayers have been proposed as templates to generate stable, self-organized nanostructures at large length scales, with a variety of important technological applications. However, modeling strain-driven self-organization is a formidable challenge due to different length scales involved. In this Letter, we present a method for predicting the patterning of ultrathin films on micron length scales with atomic resolution. We make quantitative predictions for the type of superstructures (stripes, honeycomb, triangular) and length scale of pattern formation of two metal-metal systems, Cu on Ru(0001) and Cu on Pd(111). Our findings are in excellent agreement with previous experiments and call for future experimental investigations of such systems.

Elder, K. R.; Rossi, G.; Kanerva, P.; Sanches, F.; Ying, S.-C.; Granato, E.; Achim, C. V.; Ala-Nissila, T.

2012-06-01

307

Effect of metrology time delay on overlay APC  

NASA Astrophysics Data System (ADS)

The run-to-run control strategy of lithography APC is primarily composed of a feedback loop as shown in the diagram below. It is known that the insertion of a time delay in a feedback loop can cause degradation in control performance and could even cause a stable system to become unstable, if the time delay becomes sufficiently large. Many proponents of integrated metrology methods have cited the damage caused by metrology time delays as the primary justification for moving from a stand-alone to integrated metrology. While there is little dispute over the qualitative form of this argument, there has been very light published about the quantitative effects under real fab conditions - precisely how much control is lost due to these time delays. Another issue regarding time delays is that the length of these delays is not typically fixed - they vary from lot to lot and in some cases this variance can be large - from one hour on the short side to over 32 hours on the long side. Concern has been expressed that the variability in metrology time delays can cause undesirable dynamics in feedback loops that make it difficult to optimize feedback filters and gains and at worst could drive a system unstable. By using data from numerous fabs, spanning many sizes and styles of operation, we have conducted a quantitative study of the time delay effect on overlay run- to-run control. Our analysis resulted in the following conclusions: (1) There is a significant and material relationship between metrology time delay and overlay control under a variety of real world production conditions. (2) The run-to-run controller can be configured to minimize sensitivity to time delay variations. (3) The value of moving to integrated metrology can be quantified.

Carlson, Alan; DiBiase, Debra

2002-07-01

308

Calibrated Landsat ETM+ nonthermal-band image mosaics of Afghanistan  

USGS Publications Warehouse

In 2005, the U.S. Agency for International Development and the U.S. Trade and Development Agency contracted with the U.S. Geological Survey to perform assessments of the natural resources within Afghanistan. The assessments concentrate on the resources that are related to the economic development of that country. Therefore, assessments were initiated in oil and gas, coal, mineral resources, water resources, and earthquake hazards. All of these assessments require geologic, structural, and topographic information throughout the country at a finer scale and better accuracy than that provided by the existing maps, which were published in the 1970s by the Russians and Germans. The very rugged terrain in Afghanistan, the large scale of these assessments, and the terrorist threat in Afghanistan indicated that the best approach to provide the preliminary assessments was to use remotely sensed, satellite image data, although this may also apply to subsequent phases of the assessments. Therefore, the first step in the assessment process was to produce satellite image mosaics of Afghanistan that would be useful for these assessments. This report discusses the production and characteristics of the fundamental satellite image databases produced for these assessments, which are calibrated image mosaics of all six Landsat nonthermal (reflected) bands.

Davis, Philip A.

2006-01-01

309

Evaluation of MSS Landsat imagery over central Spain  

NASA Astrophysics Data System (ADS)

Twenty four MSS Landsat I and II images have been selected to determine the most persistent lineaments within a given area in Central Spain. This area comprises four different geotectonic units: the Hercynian basement, an intermediate-type Alpine chain and two undeformed Tertiary basins. Lineaments appear to be well established in the Iberian Peninsula and their general pattern in good accordance with the faults system. Some of them correspond to simple or composite linears that extend over the entire peninsula, and must affect the whole crust. A generalized late-Hercynian fracture event is admitted to be the origin of these linears and their extension into the post-Hercynian areas is related to an Alpine reactivation. The main lineament directions are NS, N20, N70, N120 and N160. These trends seem to correlate well with arches and troughs inferred from gravimetric and aeromagnetic surveys carried out over both Tertiary basins. BPCG, Sn, W mineralizations within the Hercynian basement occur in relation to quartz and baryte dykes trending N20, N70, and N120.

Antón-Pacheco, C.; Garzón, G.; Ubanell, A. G.; Vegas, R.; Roiz, J. M.

310

The Kuwait oil fires as seen by Landsat  

NASA Astrophysics Data System (ADS)

A mosaic of two Landsat thematic mapper images acquired May 30, 1991, reveals a dark smoke plume 30-60 km wide extending hundreds of kilometers south of Kuwait City along the Persian Gulf. Smoke coming from the Raudhatain and Sabriyah oil fields blew across the Gulf of Kuwait and over Kuwait City, joined with smoke from the Greater Burgan and Minagish fields, and continued southward over smaller villages and regions of desert agriculture consisting of hundreds of axially irrigated fields in both Kuwait and Saudi Arabia. One agricultural region in Kuwait was completely obscured by the smoke. The light colored limestone gravel and sand surface was darkened by oil lakes near the wells, and by oil drizzling out of the plume downwind of the wells. Most fires produced either a light or dark plume, and the separate plumes mixed to form a combined plume much darker than the land surface, but slightly more reflective than the Gulf waters. A few of the hottest fires had no visible plume, and are presumably associated with methane combustion. The last of the Kuwait fires was reportedly extinguished in November of 1991. Continued monitoring is needed to assess the impact of emissions from both burning and nonburning oil wells on the region's climate, as well as on the agriculture, fishing, and other activities essential to life in the region.

Cahalan, Robert F.

1992-09-01

311

LANDSAT M. S. S. IMAGE MOSAIC OF TUNISIA.  

USGS Publications Warehouse

The Landsat mosaic of Tunisia funded by USAID for the Remote Sensing Laboratory, Soils Division, Ministry of Agriculture, Tunisia, was completed by the USGS in September 1983. It is a mixed mosaic associating digital corrections and enhancements to manual mosaicking and corresponding to the Tunisian request for high resolution and the limited available funds. The scenes were processed by the Environmental Research Institute of Michigan, resampling the data geodesically corrected to fit the Universal Transverse Mercator projection using control points from topographic maps at 1:50,000 and 1:100,000 scales available in the U. S. The mosaicking was done in the Eastern Mapping Center under the supervision of the Graphic Arts System Section. The three black and white mosaics were made at the 1:1,000,000 scale and various products generated. They included color film positives at 1:2,000,000 and 1:4,000,000 scales reproducible in the Remote Sensing Laboratory in Tunis and corresponding color prints as well as tricolor prints at various scales from 1:500,000 to 1:2,000,000.

Boswell-Thomas, J. C.

1984-01-01

312

Quantifying Wetland Dynamics and Hydrologic Function with Landsat Thematic Mapper  

NASA Astrophysics Data System (ADS)

The Prairie Pothole Region (PPR) of North America spans the glaciated prairies from Alberta, Canada, to central Iowa. The region contains hundreds of thousands of wetlands that provide habitat for an estimated 50 to 80 percent of North America's waterfowl. The composition of species that use the PPR are a function of wetland water chemistry. The water chemistry is driven by wetland functional processes that determine hydrogeochemical interactions of surface water, ground water, and their connectivity to other wetlands. As wetlands cycle from drought to deluge, significant surface water fluctuations can alter water chemistry and hydroperiods, influencing the composition of wetland communities. We quantified these temporal water dynamics with Landsat TM and ETM+ imagery, spanning a 17-year period during a drought-deluge cycle. Using clustering techniques, we grouped wetlands based on their functional responses to climate and quantified the traits of each cluster. We found that wetlands receiving groundwater discharge respond very differently to climatic shifts than wetlands functioning as recharge basins. In addition, wetlands with closed basins are less dynamic than wetlands located in open basins. Accuracies of the initial classification ranged from 75 to 100 percent. This study offers the first insight into wetland dynamics at a regional scale with implications for modeling biogeochemistry and ecosystem services across the PPR. Although this method was developed in the Missouri Coteau and nearby drift plains of the PPR, we believe this technique is applicable to other regions.

Rover, J. A.; Wright, C.; Wylie, B. K.; Euliss, N. H.

2007-12-01

313

Assessing ground water development potential using landsat imagery.  

PubMed

Seven villages in southeastern Kenya surround Mt. Kasigau and depend on the mountain's cloud forest for their water supply. Five of these villages have regularly experienced water shortages, and all village water supplies were contaminated with Escherichia coli bacteria. There is a need to economically find new sources of fresh ground water. Remote sensing offers a relatively quick and cost-effective way of identifying areas with high potential for ground water development. This study used spectral properties of features on Landsat remote sensing imagery to map linear features, soil types, surface moisture, and vegetation. Linear features represented geologic or geomorphologic features indicating either shallow ground water or areas of increased subsurface hydraulic conductivity. Regarding soil type, black soils were identified as potential indicators of shallow aquifers based on their relatively lower elevation and association with river valleys. A vegetation map was created using unsupervised classification, and three of the resulting vegetation classes were observed to be commonly associated with wet areas and/or ground water discharge. A wetness map, created using tasseled cap analysis, was used to identify all areas of high ground moisture, including those that corresponded to vegetated areas. The linear features, soil type, vegetation, and wetness maps were overlaid to produce a composite that highlighted areas with the highest potential for ground water development. Electrical resistivity surveys confirmed that areas highlighted by the composite image had relatively shallow depths to the water table. Some figures in this paper are available in color in the online version of the paper. PMID:19210559

Mutiti, Samuel; Levy, Jonathan; Mutiti, Christine; Gaturu, Ndung'u S

2008-12-16

314

Siberian taiga forest regeneration monitoring with winter LANDSAT ETM+ images  

NASA Astrophysics Data System (ADS)

Monitoring the post-fire regeneration is important for Siberian taiga forest where fires occur frequently. Satellite images taken in summer have been often used in analyses of vegetation. However, in the sparse stands of Siberian taiga forest with varied types of forest floors, it is difficult to extract high trees' conditions and distributions from those images. Instead, we used for the analysis the LANDSAT ETM+ images taken in winter, when almost all high tree species there had fallen their leaves down and the forest floor was covered homogeneously by snow, which had very high reflectance in visible and low reflectance in longer wavelength. Bands 2 (visible), 4 (near-infrared), and 5 (mid-infrared) of the winter ETM+ images are compared with stands' basal area (BA) and height density (HD) that represents a relative congestion of the forest crown above observed from the floor. The results show that the total BA has a correlation with the visible band where the contrast of reflectance between trees and snow is maximum, while total HD has a relationship with the middle infrared band where the contrast is minimum. In addition, the near infrared has a relation ship with the BA of pines that are the only evergreen species of the region. Since HD has a positive correlation with the stand density, HD can be then interpreted to stand density and DBH.

Takao, G.; Kushida, K.; Maximov, T. C.; Kononov, A. V.; Desyatkin, R. M.; Fedorov, A. N.; Torgovkin, Y. Y.

2001-12-01

315

Validation of Fractional Snow Cover from AVHRR using Landsat TM  

NASA Astrophysics Data System (ADS)

The suite of NOAA satellites carrying the AVHRR sensor provides daily coverage of the world's snowpack. While another satellite-borne sensor, MODIS, may provide more accurate estimates of snow cover for operational forecasting, AVHRR provides a retrospective view, gaining a perspective of historical snowpack, which in turn can supplement operational forecasting. Here we validate a fractional snow cover algorithm for AVHRR in use by the Cold Regions Research and Engineering Laboratory. The approach uses a binary decision tree trained from the theoretical reflectance of snow and non-snow spectra convolved to AVHRR bandwidths. The binary decision tree, which estimates fractional snow cover, uses bands 1 and 2 calibrated with an atmosphere optical model 6S, and a derived band 3, which estimates a reflectance component separated from the emitance component by using temperature data from channel 4, and assumptions about the surface emissivity. Using 26 Landsat TM scenes we validate 79 scenes from NOAA 9, 11, 12 and 14. We investigate the absolute differences from the fine resolution data as well as the relative differences between sensors on the two satellites. Errors of commission are eliminated with a temperature and/or elevation mask. Like most moderate resolution satellite data, georegistration errors contribute to the overall error and can be accounted for when comparing images. The AVHRR algorithm demonstrates sensitivity to fractional snow cover and performs well in comparison to TM.

McKenzie, C.; Rittger, K.; Dozier, J.; Davis, R.

2008-12-01

316

Metodologia Para a Confeccao de Mapas Tematicos Utilizando Dados T.M.-LANDSAT (Methodology for the Elaboration of Thematic Maps Utilizing LANDSAT-TM Data).  

National Technical Information Service (NTIS)

A methodology for the elaboration of thematic maps for military use in the scale of 1:100,000 is developed. Techniques of digital processing and visual analysis of remote sensing images were used. The thematic mapper sensor of the LANDSAT Satellite was em...

L. A. Deandrade

1986-01-01

317

Mapas Tematicos Utilizando Dados Do Sensor Thematic Mapper Do Satelite LANDSAT (Thematic Mapping Utilizing Data from the Thematic Mapper Sensor of the Landsat Satellite).  

National Technical Information Service (NTIS)

A methodology for the elaboration of thematic maps in the scale 1:100,000 is developed. Techniques of digital processing and visual analysis of remote sensing images were used. The Thematic Mapper of the LANDSAT satellite was employed and the selected are...

L. Antoniodeandrade

1986-01-01

318

Investigation of systematical overlay errors limiting litho process performance of thick implant resists  

NASA Astrophysics Data System (ADS)

Tapered resist profiles have been found to cause a deterimental effect on the overlay measurement capability, affecting lithography processes which utilize thick implant resist. Particularly, for resist thicknesses greater than 1.5 ?m, the systematical contribution to the overlay error becomes predominant. In CMOS manufacturing, these resist types are being used mainly for high energy well implants. As design rules progressively shrink, the overlay requirements are getting tighter, such that the limits of the process capability are reached. Since the resist thickness cannot be reduced due to the requirements of the implant process, it becomes inevitable to reduce the systematical overlay error for the litho process involving thick resists. The following analysis concentrates on the tapers of overlay marks printed on thick i-line positive resists. Conventionally, overlay between two litho layers is measured from box in box marks with respect to a reference layer where the statistical shift between the boxes is expected to provide the biggest source of residuals. We observed however that an even bigger error could be introduced by an unevenness of the i-line resist tapers, adding asymmetrical chip magnification. The inclination of these tapers depends on the proximity and surface of the surrounding features and stack variations. We show that by adjusting soft and hard bake temperatures and times, tapers can be significantly reduced and thereby the overlay performance was greatly improved.

Grandpierre, Alexandra G.; Schiwon, Roberto; Bruch, Jens-.; Nacke, Christoph; Schroeder, Uwe P.

2004-05-01

319

An extensive and diverse set of molecular overlays for the validation of pharmacophore programs.  

PubMed

The pharmacophore hypothesis plays a central role in both the design and optimization of drug-like ligands. Pharmacophore patterns are invoked to explain the binding affinity of ligands and to enable the design of chemically distinct scaffolds that show affinity for a protein target of interest. The importance of pharmacophores in rationalizing ligand affinity has led to numerous algorithms that seek to overlay ligands based on their pharmacophoric features. All such algorithms must be validated with respect to known ligand overlays, usually by extracting ligand overlay sets from the Protein Data Bank (PDB). This validation step creates the problem of which of the known overlays to select and from which proteins. The large number of structures and protein families in the PDB makes it difficult to establish a definitive overlay set; as a result, validation studies have rarely employed the same data sets. We have therefore undertaken an exhaustive analysis of the RCSB PDB to identify 121 distinct ligand overlay sets. We have defined a robust protein overlay protocol, which is free from subjective interpretation over which residues to include, and we have analyzed each overlay set on the basis of whether they provide evidence for the pharmacophore hypothesis. Our final data set spans a broad range of structural types and degrees of difficulty and includes overlays that any algorithm should be able to reproduce, as well as some for which there is very weak evidence for a conserved pharmacophore at all. We provide this set in the hope that it will prove definitive, at least until the PDB is greatly enriched with further structures or with radically different protein folds and families. Upon publication, the data set will be available for free download from the Web site of the Cambridge Crystallographic Data Centre. PMID:23565904

Giangreco, Ilenia; Cosgrove, David A; Packer, Martin J

2013-04-08

320

Medium Resolution Global Earth Observations with Landsat: Looking 35 Years Back and 50 Years Forward  

NASA Astrophysics Data System (ADS)

The modern era of global medium resolution satellite remote sensing was inaugurated 35 years ago, in July 1972, with the launch of the first Landsat satellite carrying the Multispectral Scanner (MSS) sensor. Ten years after that first launch, Landsat 4 carried a much-improved sensor aloft, the Thematic Mapper. The TM provided better spatial resolution (30 m versus 79 m) than the MSS, as well as additional spectral bands in the mid- infrared (IR) and thermal IR regions. Roughly another decade later, in April 1999, the Enhanced Thematic Mapper Plus (ETM+) instrument was placed in orbit on Landsat 7. The ETM+ provided a new 15 m panchromatic band and a much-improved thermal band resolution (60 m versus 120 m). Through a combination of planning and good luck, the various Landsat missions have delivered a continuous set of calibrated, multispectral images of the Earth's surface spanning this entire 35-year time period. This imagery database has been used in agricultural evaluations, forest management inventories, geological surveys, water resource estimates, coastal zone appraisals, and a host of other applications to meet the needs of a very broad user community, including business, government, science, education, national security, and now -- even the casual observer -- as Landsat imagery provides the skeletal backbone of Google Earth. Landsat established the U.S. as the world leader in terrestrial remote sensing, contributed significantly to the understanding of the Earth's environment, spawned revolutionary uses of space-based data by the commercial value-added industry, and encouraged a new generation of commercial satellites that provide regional, high-resolution spatial images. In spite of the overall success of the Landsat series of satellites, the first 35 years of the Landsat legacy have been extremely challenging as the push to embrace new technologies was often questioned by those who simply wanted to maintain whatever the current capability was at that point in time. For example, the early days of the TM provided a data rate and storage volume that most users did not have the capability to handle computationally. In addition to these technology-based debates, the Landsat program experienced continuous turmoil and unknowns when it came to the funding and management oversight of each subsequent mission. Following years of debate, in August 2007, the Office of Science and Technology Policy (OSTP) at the White House issued a press release announcing the creation of the National Land Imaging Program (NLIP) to ensure the availability of Landsat class data far into the future. The NLIP is to provide a mechanism within the Interior Department to assess the land imagery needs of federal, state and local land management officials, scientists, and geographic researchers, and to translate those needs into the technical capabilities of future satellites. Thus, continuity of digital image data provided by the Landsat series of satellites looks to be very promising. As stated in the descriptive paragraph for this session, the need for monitoring the Earth is now more acute than ever, and the development and implementation of useful long-term global observations, such as the Landsat series of satellites has provided, is one of the major scientific challenges of our time. We propose to document the lessons learned from Landsat's global observations in recent decades, and to apply these lessons to analysis of current and future needs.

Williams, D. L.; Irons, J. R.; Goward, S. N.

2007-12-01

321

Evaluation of Three Techniques for Classifying Urban Land Cover Patterns Using Landsat Mss Data.  

National Technical Information Service (NTIS)

Three computer quantitative techniques for determining urban land cover patterns are evaluated. The techniques examined deal with the selection of training samples by an automated process, the overlaying of two scenes from different seasons of the year, a...

P. R. Baumann

1979-01-01

322

Outgassing models for Landsat-4 thematic mapper short wave infrared bands  

USGS Publications Warehouse

Detector responses to the Internal Calibrator (IC) pulses in the Landsat-4 Thematic Mapper (TM) have been observed to follow an oscillatory behavior. This phenomenon is present only in the Short Wave Infrared (SWIR) bands and has been observed throughout the lifetime of the instrument, which was launched in July 1982 and imaged the Earth's surface until late 1993. These periodic changes in amplitude, which can be as large as 7.5 percent, are known as outgassing effects and are believed to be due to optical interference caused by a gradual buildup of an ice-like material on the window of the cryogenically cooled dewar containing the SWIR detectors. Similar outgassing effects in the Landsat-5 TM have been characterized using an optical thin-film model that relates detector behavior to the ice film growth rate, which was found to gradually decrease with time. A similar approach, which takes into consideration the different operational history of the instrument, has been applied in this study to three closely sampled data sets acquired throughout the lifetime of the Landsat-4 TM. Although Landsat-4 and Landsat-5 Thematic Mappers are essentially identical instruments, data generated from analyses of outgassing effects indicate subtle, but important, differences between the two. The estimated lifetime model could improve radiometric accuracy by as much as five percent.

Micijevic, E.; Helder, D. L.

2005-01-01

323

Uso DA Expansao Direta Para Estimar Areas de Soja E Milho Atraves de Dados Multiespectrais E Temporais Do Landsat/TM (Use of Direct Expansion for Estimation of Soybean and Corn Areas Through Multispectral and Temporal Landsat/TM Data).  

National Technical Information Service (NTIS)

The contribution of LANDSAT/TM data in estimating soybean and corn areas was analyzed through a direct expansion method by sampling techniques. The study was carried out in the test site of Distrito Federal (5,814 sq km), covered by LANDSAT/TM (row/path 2...

M. Alvesmoreira

1990-01-01

324

Comparison and integration of Landsat optical and PALSAR quad polarization radar: a case study in Bangladesh  

NASA Astrophysics Data System (ADS)

With the recent increase in the availability of quad polarization radar data, the need to assess the utility of these datasets for land cover/use classification is important. The relative classification accuracies of four land covers/uses in Bangladesh using spaceborne quad polarization radar from the Japanese ALOS PALSAR system and optical Landsat Thematic Mapper (TM) data were evaluated. In addition, the utility of radar texture and sensor fusion were analyzed. Supervised signature extraction and classification (maximum likelihood) were used to classify different land covers/uses followed by an accuracy assessment. The original four-band radar had an overall accuracy of 91%. Variance texture was the most useful of the four measures examined, but did not improve overall or individual class accuracies over the original radar. Landsat provided a higher overall classification accuracy (94%) as compared to radar. The merger of Landsat with the original radar increased overall accuracy to 99%, which indicates the advantages of sensor integration.

Sheoran, Arjun; Haack, Barry

2013-01-01

325

A time-series analysis of flood disaster around Lena river using Landsat TM/ETM+  

NASA Astrophysics Data System (ADS)

Landsat satellite has provided a continuous record of earth observation since 1972, gradually improving sensors (i.e. MSS, TM and ETM+). Already processed archives of Landsat image are now available free of charge from the internet. The Landsat image of 30 m spatial resolution with multiple spectral bands between 450 and 2350 nm is appropriate for detailed mapping of natural resource at wide geographical areas. However, one of the biggest concerns in the use of Landsat image is the uncertainty in the timing of acquisitions. Although detection of land cover change usually requires acquisitions before and after the change, the Landsat image is often unavailable because of the long-term intervals (16 days) and variation in atmosphere. Nearly cloud-free image is acquired at least once per year (total of 22 or 23 scenes per year). Therefore, it may be difficult to acquire appropriate images for monitoring natural disturbances caused at short-term intervals (e.g., flood, forest fire and hurricanes). Our objectives are: (1) to examine whether a time-series of Landsat image is available for monitoring a flood disaster, and (2) to evaluate the impact and timing of the flood disaster around Lena river in Siberia. A set of Landsat TM/ETM+ satellite images was used to enable acquisition of cloud-free image, although Landsat ETM+ images include failure of the Scan Line Corrector (SLC) from May 2003. The overlap area of a time series of 20 Landsat TM/ETM+ images (path 120-122, row 17) from April 2007 to August 2007 was clipped (approximately 33 km × 90 km), and the other area was excluded from the analyses. Image classification was performed on each image separately using an unsupervised ISODATA method, and each Landsat TM/ETM+ image was classified into three land cover types: (1) ice, (2) water, and (3) land. From three land cover types, the area of Lena river was estimated. The area of Lena river dramatically changed after spring breakup. The middle part of Lena river around Tabaga (61.83°N, 129.60°E) was frozen hard until early May 2007. River-ice breakup began in patches on 13 May 2007. Then, the area of Lena river rapidly increased due to overhead flooding on 14 May 2007, and reached the peak on 15 May 2007. In the brief period of one or two days, the area of Lena river was more than twice. After this, the area of Lena river exponentially decreased over three months, and it was quite stable in late August 2007. A time-series of Landsat TM/ETM+ images could detect these large temporal variations. In addition, the temporal variations in the area of Lena river synchronized with water stage measured in the field. These results indicate that a time-series of Landsat TM/ETM+ images enables to monitor natural disturbances caused at short-term intervals, although significantly limited to local scales. The requirement of spatial and temporal resolution is often application specific in the context of the desired measurement goals. This type of research and resultant information is critical for the utilization of remote sensing data to the fullest extent.

Sakai, Toru; Hatta, Shigemi; Okumura, Makoto; Takeuchi, Wataru; Hiyama, Tetsuya; Inoue, Gen

2010-05-01

326

Scene selection and the use of NASA's global orthorectified Landsat dataset for land cover and land use change monitoring.  

PubMed

This study examines the utility of NASA's circa 1990 and circa 2000 global orthorectified Landsat dataset for land cover and land use change mapping and monitoring across Africa. This is achieved by comparing the temporal and spatial variation of NDVI, measured independently by the NOAA-AVHRR at the time of Landsat scene acquisition, against the seasonal mean for each Landsat scene extent. Decadal sequences of drift-corrected NOAA-AVHRR imagery were used to calculate NDVI means and standard deviations for the periods covered by the scenes composing the c.1990 and c.2000 Landsat datasets. The specific NOAA-AVHRR NDVI values at the acquisition date of each individual Landsat scene were also calculated and the differences, both from the mean and scaled by standard deviation, were mapped for the Landsat scene footprints in the c.1990 and c.2000 datasets. The resulting maps show the temporal position of each Landsat scene within the seasonal NDVI cycle, and provide a valuable guide to assist in quantifying uncertainty and interpreting land cover and land use changes inferred from these Landsat data. PMID:21994469

Tatem, Andrew J; Nayar, Anjali; Hay, Simon I

2007-02-22

327

Use of Landsat data for automatic classification and area estimation of sugar-cane plantation in Sao Paulo state, Brazil  

Microsoft Academic Search

Sugar-cane (saccharum spp.) plantations in São Paulo State were classified automatically using an lmage-100 system and Landsat digital data. Ten segments of size 10 × 20 km were aerially photographed and used as training areas for automatic classification. The study area was covered by four Landsat paths, 235, 236, 237 and 238. The percentages of overall correct classification for these

FRANCISCO JOSÉ MENDONCA

1981-01-01

328

Remote sensing of urban areas: linear spectral unmixing of Landsat Thematic Mapper images acquired over Tartu (Estonia)  

Microsoft Academic Search

Urban areas are characterized by a pattern of very heterogeneous patches resulting from the co-occurrence of different materials within the ground instantaneous field of view of a moderate resolution scanner, e.g. Landsat Thematic Mapper (TM). The main objective of this study was to map vegetation, impervious surface, and soil from Landsat TM images acquired over the town of Tartu (Estonia)

Tõnis Kärdi

2007-01-01

329

Continuously Reinforced Concrete Overlays of Flexible Pavements on Trunk Road A2.  

National Technical Information Service (NTIS)

The design and construction of continuously reinforced concrete (CRC) overlays on flexible pavements of Trunk Road A2 are described. The existing pavements were dual carriageways of flexible construction built in 1975-76; isolated sections had failed comp...

J. M. Gregory

1983-01-01

330

Origin of spurious ultrasonic echoes in stainless steel piping with weld overlay  

SciTech Connect

The initiation and growth of intergranular stress-corrosion cracking (IGSCC) in the heat affected zone (HAZ) of stainless steel reactor piping welds has been a subject of concern to electric utilities for over ten years. This type of crack can be detected with ultrasonic shear waves during normal maintenance periods with a reliability of up to 80%. Often after an inspection indicating cracks, a utility has been allowed to administer a temporary fix to a pipe which is suspected of being cracked. This fix is a weld metal overlay. The repaired pipes often have to be inspected after the overlay has been put on the pipe. The overlay with a complex, elastically anisotropic microstructure, considerably reduces the reliability of the ultrasonic inspection. This paper addresses the problems arising because of the overlay.

Kupperman, D.S.

1986-08-01

331

Toward perfect on-wafer pattern placement: stitched overlay exposure tool characterization  

NASA Astrophysics Data System (ADS)

Continued lithographic pattern density scaling depends on aggressive overlay error reduction.1,2 Double patterning processes planned for the 22nm node require overlay tolerances below 5 nm; at which point even sub-nanometer contributions must be considered. In this paper we highlight the need to characterize and control the single-layer matching among the three pattern placement mechanisms intrinsic to step&scan exposure - optical imaging, mask-to- wafer scanning, and field-to-field stepping. Without stable and near-perfect pattern placement on each layer, nanometer-scale layer-to-layer overlay tolerance is not likely to be achieved. Our approach to understanding onwafer pattern placement is based on the well-known technique of stitched field overlay. We analyze dense sampling around the field perimeter to partition the systematic contributors to pattern placement error on representative dry and immersion exposure tools.

Ausschnitt, Christopher P.; Brunner, Timothy A.; Felix, Nelson M.; Minghetti, Blandine

2010-03-01

332

Investigation into Shrinkage of High-Performance Concrete Used for Iowa Bridge Decks and Overlays.  

National Technical Information Service (NTIS)

High-performance concrete (HPC) overlays have been used increasingly as an effective and economical method for bridge decks in Iowa and other states. However, due to its high cementitious material content, HPC often displays high shrinkage cracking potent...

H. Senevirante K. Wang S. Sritharan S. M. Schlorholtz X. Hou X. Wang

2013-01-01

333

A spatial overlay analysis method for three-dimensional vector polyhedrons  

Microsoft Academic Search

Three-dimensional spatial overlap analysis (3DSOA) has become a bottleneck in the development of three-dimensional Geographic Information System (3DGIS). Three-dimensional spatial overlay analysis method for vector polyhedrons is the key problem of three-dimensional spatial overlap analysis which still lacks complete solutions. This paper proposes a method for three dimensional spatial vector polyhedrons overlay analysis. First of all, it describes topological relationships

Yanjun Guo; Mao Pan; Zhe Wang; Honggang Qu; Xiangrong Lan

2010-01-01

334

Electrochemical behaviour of pseudomorphic overlayers: Pd on Au(1 1 1)  

Microsoft Academic Search

The electrochemical properties of palladium adlayers on Au(111) are compared with those of massive Pd(111). Electro-deposited Pd forms a pseudomorphic overlayer on the unreconstructed Au(111) surface following the stacking sequence of the substrate. The altered electrochemical behaviour of the overlayer can be ascribed to changes in the electronic structure due to lateral strain. A gradual change to bulk properties is

L. A Kibler; A. M El-Aziz; D. M Kolb

2003-01-01

335

Effect of overlay APC control on cascading levels: pertrubations of the reference level  

Microsoft Academic Search

Driven by overlay shrinks and increasing product diversification in advanced fabs, automatic control of correctable overlay coefficients has become critical to semiconductor manufacturing. Although numerous reports have shown the compelling benefits of automatic run-to-run feedback control, one important issue has received very little attention to date. In many state-of-the-art fabs, reticle to wafer alignment is performed against marks that were

Timothy H. Conway; Manish Misra; Alan P. Carlson; David A. Crow

2003-01-01

336

Self-organisation of nanoscaled pores in anodic oxide overlayer on stainless steels  

Microsoft Academic Search

The nanoscaled morphology of the overlayer covering stainless steels after electropolishing in perchloric acid-based electrolyte was explored mainly by AFM and SEM. Two kinds of stainless steels were tested. For the austenitic one (AISI 304L), a quasi-periodic arrangement of pores in this overlayer has been observed. Depending on the experimental conditions, the distance between neighbouring pores ranged from 20nm up

F. Martin; D. Del Frari; J. Cousty; C. Bataillon

2009-01-01

337

Cost efficient LSP protection in IP\\/MPLS-over-WDM overlay networks  

Microsoft Academic Search

We consider an IP\\/MPLS-over-WDM overlay network, which an IP\\/MPLS service layer exists independently over a WDM transport network. In the overlay model, two adjacent layers communicate with each other only through a pre-defined user-network interface (UNI) and the WDM topology information is not available to the service layer. In this paper, we concentrate on network design with a fault tolerance

Sunggy Koo; Gokhan Sahin; Suresh Subramaniam

2003-01-01

338

IQ-Paths: Predictably High Performance Data Streams Across Dynamic Network Overlays  

Microsoft Academic Search

Overlay networks are a key vehicle for delivering network and processing resources to high performance applications. For shared\\u000a networks, however, to consistently deliver such resources at desired levels of performance, overlays must be managed at runtime,\\u000a based on the continuous assessment and prediction of available distributed resources. Data-intensive applications, for example,\\u000a must assess, predict, and judiciously use available network paths,

Zhongtang Cai; Vibhore Kumar; Karsten Schwan

2007-01-01

339

Interactive Guidance by Image Overlay in Robot Assisted Coronary Artery Bypass  

Microsoft Academic Search

\\u000a We present an original visual guidance system in the especially difficult context of robot assisted coronary artery bypass\\u000a graft. The overlay of a preoperative coronary tree model on the endoscopic images is initialized to help the surgeon to locate\\u000a himself. Then the surgeon points some landmarks observed in the operating field during the motion of the endoscope. The overlay\\u000a is

Fabien Mourgues; Thierry Viéville; Volkmar Falk; Ève Coste-manière

2003-01-01

340

On the Effectiveness of Secure Overlay Forwarding Systems under Intelligent Distributed DoS Attacks  

Microsoft Academic Search

Abstract In the framework of a set of clients communicating with a critical server over the Internet, a recent approach to protect communication,from Distributed Denial of Service (DDoS) attacks involves the usage of overlay systems. SOS, MAYDAY and I3 are such systems. The overlay system serves as an intermediate forwarding system between the clients and the server, where the systems

Xun Wang; Sriram Chellappan; Phillip Boyer; Dong Xuan

2006-01-01

341

Synthesis and structural study of nano\\/micro diamond overlayer films  

Microsoft Academic Search

The nano\\/micro diamond overlayer films have been successfully fabricated by means of bias growth technique using microwave plasma-enhanced chemical vapor deposition method. During the diamond growth, as a negative bias (?100V) is applied midway on the substrate side, the nanocrystalline diamond layer can be controllably deposited on the as-grown microcrystalline diamond to form a nano\\/micro overlayer structure. Transmission electron microscopy

N. Jiang; K Sugimoto; K Nishimura; Y Shintani; A Hiraki

2002-01-01

342

A Self-organized Clustering-based Overlay Network for Application Level Multicast  

Microsoft Academic Search

Peer-to-Peer Overlay networks enabling an end- end application level-multicast service have drawn enormous attention. This paper proposes a self-organized -Multicast Overlay Network (-MON) that enables an efficient end-end application level multicast. The -MON is organized into MON-Clusters, where G is the maximum physical number of hops between any two end- nodes in each MON-Cluster. Thus, end-users accessing from

Khaled Ragab; Akinori Yonezawa

2009-01-01

343

SkipNet: A Scalable Overlay Network with Practical Locality Properties  

Microsoft Academic Search

Scalable overlay networks such as Chord, CAN, Pastry, and Tapestry have recently emerged as flex- ible infrastructure for building large peer-to-peer sys- tems. In practice, such systems have two disadvantages: They provide no control over where data is stored and no guarantee that routing paths remain within an ad- ministrative domain whenever possible. SkipNet is a scalable overlay network that

Nicholas J. A. Harvey; Michael B. Jones; Stefan Saroiu; Marvin Theimer; Alec Wolman

2003-01-01

344

An overlay multicast protocol for live streaming and delay-guaranteed interactive media  

Microsoft Academic Search

In many collaborative multimedia applications, there is often a requirement for simultaneously supporting live streaming and shareable interaction. A major challenge in designing such an application by overlay multicast is how to simultaneously provide scalable live streaming and delay-guaranteed interactive media. Live streaming by overlay multicast incurs additional application-layer latency, which conflicts with the delay-sensitive property of interactive media. To

Weizhan Zhang; Qinghua Zheng; Haifei Li; Feng Tian

345

850nm VCSEL with a liquid crystal overlay  

NASA Astrophysics Data System (ADS)

We developed an in- house technology to overlay liquid crystal (LC) on top of a 850nm Vertical Cavity Surface Emitting Laser (VCSEL) creating a so-called LC-VCSEL. Prior to this, the effect of the cell thickness on the planar alignment of the E7 LC is investigated. It is observed that the LC orientation is planar, uniformly aligned over the whole cell with an average pre-tilt of 22.50 in a thin a cell of 13?m thickness; such alignment uniformity is not observed in a thick cell of 125?m. Nevertheless, several domains of good uniformity are still present. Further, the polarization resolved LI characteristics of LC-VCSEL are investigated with and without the insertion of LC in a cell glued directly onto VCSEL package. Before filling in the LC, the VCSEL emits linearly polarized light and this linear polarization is lost after LC filling. The output intensity as a function of polarizer angle shows partial planar alignment of the E7 LC, which is very important for the further advancement of the LC-VCSEL integrated system.

Nair, Veena M.; Panajotov, Krassimir; Petrov, Mikov; Thienpont, Hugo; Xie, Yi; Beeckman, Jeroen; Neyts, Kristiaan

2012-05-01

346

VCSELs with nematic and cholesteric liquid crystal overlays  

NASA Astrophysics Data System (ADS)

We study theoretically the spectral and polarization threshold characteristics of Vertical-Cavity Surface-Emitting Lasers with nematic and cholesteric liquid crystal overlay: LC-VCSELs. In the first case, we demonstrate the possibility of selecting between two orthogonal directions of linear polarization (LP) of the fundamental mode (x or y LP) by choosing appropriate NLC length and to achieve strong polarization discrimination: threshold gain difference as large as several times the threshold gain. We also demonstrate an active control of light polarization by electro-optically tuning the LC director and show that either polarization switching between x and y LP modes or continuous change of the LP direction is possible. For cholesteric LC-VCSEL we show that it becomes a coupled system with different spectral, threshold and polarization characteristics than the ones of the stand-alone VCSEL. Due to the existence of a band gap for circularly polarized light in the liquid crystal, lasing occurs in almost circularly polarized modes at the LC side.

Panajotov, K.; Dems, M.; Belmonte, C.; Thienpont, H.; Xie, Y.; Beeckman, J.; Neyts, K.

2013-03-01

347

Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens  

SciTech Connect

Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The Post-WOL flaw depths were approximately 10% to 56% through-wall. This study has shown the effectiveness of ultrasonic examinations of Alloy 82/182 overlaid DMW specimens. Phased-array probes with center frequency in the 0.8- to 1.0-MHz range provide a strong coherent signal but the greater ultrasonic wavelength and larger beam spot size prevent the reliable detection of small flaws. These small flaws had nominal through-wall depths of less than 15% and length in the 50-60 mm (2-2.4 in.) range. Flaws in the 19% and greater through-wall depth range were readily detected with all four probes. At the higher frequencies, the reflected signals are less coherent but still provide adequate signal for flaw detection and characterization. A single inspection at 2.0 MHz could provide adequate detection and sizing information but a supplemental inspection at 1.0 or 1.5 MHz is recommended.

Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Moran, Traci L.; Anderson, Michael T.

2012-06-30

348

Deployable Overlay Network for Defense against Distributed SYN Flood Attacks  

NASA Astrophysics Data System (ADS)

Distributed denial-of-service attacks on public servers have recently become more serious. Most of them are SYN flood attacks, since the malicious attackers can easily exploit the TCP specification to generate traffic making public servers unavailable. We need a defense method which can protect legitimate traffic so that end users can connect the target servers during such attacks. In this paper, we propose a new framework, in which all of the TCP connections to the victim servers from a domain are maintained at the gateways of the domain (i. e., near the clients). We call the nodes maintaining the TCP connection defense nodes. The defense nodes check whether arriving packets are legitimate or not by maintaining the TCP connection. That is, the defense nodes delegate reply packets to the received connection request packets and identify the legitimate packets by checking whether the clients reply to the reply packets. Then, only identified traffic are relayed via overlay networks. As a result, by deploying the defense nodes at the gateways of a domain, the legitimate packets from the domain are relayed apart from other packets including attack packets and protected. Our simulation results show that our method can protect legitimate traffic from the domain deploying our method. We also describe the deployment scenario of our defense mechanism.

Ohsita, Yuichi; Ata, Shingo; Murata, Masayuki

349

Providing public standardized data access function: Lessons learned from accessing USGS Landsat archive  

USGS Publications Warehouse

The geospatial community is experiencing a shift from having data locally to sharing them over the Web. However, not all the data accessing systems are built in compliance with open geospatial standards and thus are weak in terms of interoperability. The USGS Landsat data are now available through free electronic access though not yet through standard Web service interfaces. This paper intends to discuss the experience and lessons learned from integrating a public data access function to the USGS Landsat data archive into a geospatial workflow environment. Currently available systems and their problems, proposed solutions and application scenarios are discussed.

Cheng, X.; Bai, Y.; Di, L.; Nebert, D.

2009-01-01

350

Effects of the atmosphere on the detection of surface changes from Landsat multispectral scanner data.  

USGS Publications Warehouse

The atmospheric effects on radiometric data recorded in the Landsat bands are compiled for cases of representative and ideal atmospheric conditions. The effects are expressed as a difference between the Earth's surface spectral reflectivity, a0, and the surface-atmosphere system spectal reflectivity, as, derived from the satellite data. These effects on the monitoring of surface changes by the use of Landsat MSS data are discussed in terms of departures of the actual atmosphere at the time of a satellite passage from a minimal atmosphere having no aerosols and characterized by gaseous absorption corresponding to minimal water vapour amounts.-from Authors

Otterman, J.; Robinove, C. J.

1981-01-01

351

Comparison of ELAS classification and density slicing Landsat data for water-surface area assessment  

Microsoft Academic Search

The techniques of density slicing and the Earth Resources Laboratory Appli­ cation Software (ELAS) classification of the Landsat data were used to assess water-surface area. Landsat data dated 9\\/16\\/72, 4\\/19\\/73, 2\\/27\\/74, 3\\/17\\/74, 10\\/19\\/74. 1\\/22\\/76 and 2\\/9\\/76 were used to assess the water-surface areas in Lake Washington, Florida. The results showed that both techniques were quite applicable for assessing the water-surface

S. F. SHIH

352

Application Oriented Flow Routing Algorithm for VoIP Overlay Networks  

NASA Astrophysics Data System (ADS)

Overlay networks which are dynamically created over underlying IP networks are becoming widely used for delivering multimedia contents since they can provide several additional user-definable services. Multiple overlay paths between a source-destination overlay node pair are designed to improve service robustness against failures and bandwidth fluctuation of the underlying networks. Multimedia traffic can be distributed over those multiple paths in order to maximize paths' utilization and to increase application throughputs. Most of flow-based routing algorithms consider only common metrics such as paths' bandwidth or delay, which may be effective for data applications but not for real-time applications such as Voice over IP (VoIP), in which different levels of such performance metrics may give the same level of the performance experienced by end users. This paper focuses on such VoIP overlay networks and proposes a novel alternative path based flow routing algorithm using an application-specific traffic metric, i.e. “VoIP Path Capacity (VPCap), ” to calculate the maximum number of QoS satisfied VoIP flows which may be distributed over each available overlay path at a moment. The simulation results proved that more QoS-satisfied VoIP sessions can be established over the same multiple overlay paths, comparing to traditional approaches.

Wipusitwarakun, Komwut; Chimmanee, Sanon

353

Hot cracking susceptibility of Alloy 52M weld overlays onto CF8 stainless steel  

NASA Astrophysics Data System (ADS)

In this study, weld overlays of Alloy 52M (a nickel-based filler metal) onto CF8 stainless steel (SS) were performed using the gas tungsten arc welding process. Hot cracking in the weld overlays was observed particularly near the interfacial region of the Alloy 52M/CF8 weld overlay. In general, the hot cracks were most likely to occur at the sites with high dilution rates, e.g., at the weld start/end locations of a single pass or in the first and second passes in multi-pass overlays. The region near the weld interface between Alloy 52M and the CF8 SS had a higher hot cracking tendency than the other regions. It was found that the dilution rate and the formation of eutectic-type constituents (i.e., ?/NbC) both played significant roles in the determination of the hot cracking susceptibility of these weld overlays. Nevertheless, hot cracks were entirely eliminated by proper deposition of a SS buffer layer prior to overlaying with Alloy 52M.

Chu, H. A.; Young, M. C.; Chu, H. C.; Tsay, L. W.; Chen, C.

2013-02-01

354

Improved CD and overlay metrology using an optical Fourier transform instrument  

NASA Astrophysics Data System (ADS)

We present an innovating method to measure the overlay by scatterometry using an optical Fourier transform (OFT) based system. In order to measure the overlay of patterned layers ? and ?, one line grating is placed in layer ? and another in layer ?. The two gratings have the same pitch and their lines are parallel. The whole scattering pattern of the double grating structure is then measured at fixed wavelength in a large range of incidence (0 to 80°) and for all the azimuth angles. This measurement is very rapid thanks to the OFT and not sensitive to vibration. The main advantage of OFT compared to standard OCD techniques like normal incidence reflectometry or spectroscopic ellipsometry is that the scattering pattern is more sensitive to overlay at an azimuth depending on the pitch value which is never parallel or perpendicular to the grooves of the gratings. In addition, the optical response is also sensitive to the sign of the overlay in addition to its amplitude. In a second method, we propose to measure the overlay simultaneously along the two directions of the plane using two bi-periodic structures patterned in layer ? and ?. By using OFT it is possible to deduce directly from the whole diffracted pattern, the overlay signs and amplitudes along both directions of the plane. The paper presents some simulations and some experimental results to illustrate this new method.

Petit, J.; Boher, P.; Leroux, T.; Barritault, P.; Hazart, J.; Chaton, P.

2005-05-01

355

Enhanced Temporal Repeat Coverage at Landsat-like Resolution - a Low-cost, Small-sat Mission Concept  

NASA Astrophysics Data System (ADS)

Landsat images have been used to document land cover and land use change since 1972, spanning a period when global populations have more than doubled, and associated land transformations have increased at an escalating rate. This 38-year Landsat global archive constitutes perhaps the most valuable global change / climate data record available to the world. In late 2008, the USGS EROS Center implemented a decision to make their deep archive of Landsat imagery available to the world community free of charge. In less than two years following that implementation of a free data policy, well over three million scenes have been downloaded and analyzed by thousands of users from 186 different countries. A bulk of the resulting image analyses has been focused on using the Landsat archive for inter-annual assessments to monitor change over time. The often dramatic change detection results have served to heighten interest in not only maintaining the continuity of Landsat imaging, but in increasing the temporal repeat frequency to obtain more robust “within season” assessment capability. The scientific utility of dramatically improved temporal repeat coverage, permitting scientists to assess the nuances of within season fluctuations in productivity at 30 m resolution, anywhere on the globe, is clearly breathtaking. Sadly, the prospect of maintaining, let alone improving upon, the 8-day temporal repeat coverage provided by Landsat’s 5 and 7 over the last decade will be hard to realize due to the escalating production costs associated with building these high precision missions (i.e., $1B). There is a need to look for dramatically lower cost options to augment, but not replace, the classic Landsat missions. A group of Earth scientists affiliated with NASA’s Goddard Space Flight Center have taken a fresh look recently at developing a low-cost, small-sat Landsat-like imaging concept. Their goal has been to derive a cost-effective alternative solution that can provide imagery of sufficient quality and quantity to augment global Landsat coverage. The effort to develop and advance this mission concept has been named LOGICAL, for Land Observations Globally In a Cost-effective Augmentation of Landsat. The approach that is being used to develop the concept will be presented, along with preliminary findings that indicate that such a mission is doable at a cost that is as much as an order of magnitude less expensive than a typical “gold standard” Landsat mission in today’s aerospace environment. If such a mission concept could be realized, it would not only serve to dramatically enhance scientific applications, but it would also reduce the risk of a devastating gap in Landsat-like imaging capability.

Williams, D. L.; Tucker, C. J.; Masek, J. G.; Brown, M. E.; Jarvis, C.

2010-12-01

356

Runoff estimation using Landsat Thematic Mapper data and the SCS model  

Microsoft Academic Search

Landform, drainage pattern, slope, soil, vegetation and land use\\/land cover, all of which control surface runoff and peak flow, can be evaluated and mapped reliably and reasonably through Landsat Thematic Mapper (TM) false colour composites of the post-monsoon season. Runoff curve numbers (CAO determined from those data predicted the runoff depth and peak flow with a coefficient of determination of

K. D. SHARMA; SURENDRA SINGH

1992-01-01

357

Volcanology from space - Using Landsat thematic mapper data in the central Andes  

Microsoft Academic Search

The use of the Landsat thematic mapper to identify potentially active Andean volcanos and to study the history of individual volcanos is discussed. A thematic mapper image of the 6150-m-high Socompa volcano is presented and it is noted that TM data have played a valuable role in tracking debris streams in the avalanche derived from the different parts of the

P. W. Francis; R. McAllister

1986-01-01

358

ESTIMATION, MAPPING AND CHANGE ANALYIS OF IMPERVIOUS SURFACE AREA BY LANDSAT REMOTE SENSING  

Microsoft Academic Search

Increasing population, new development in lake and river recreation areas, and growing towns all translate into increasing impervious surface areas across Minnesota. As urban stormwater runoff from impervious areas can have profound negative impacts to receiving waters, it is a critical new component of statewide stormwater education and management efforts. This paper describes the methods and results of Landsat classification

Marvin E. Bauer; Brian Loeffelholz; Bruce Wilson

2005-01-01

359

Monitoring of suspended sediment variation using Landsat and MODIS in the Saemangeum coastal area of Korea.  

PubMed

Suspended sediment concentration (SS) is an important indicator of marine environmental changes due to natural causes such as tides, tidal currents, and river discharges, as well as human activities such as construction in coastal regions. In the Saemangeum area on the west coast of Korea, construction of a huge tidal dyke for land reclamation has strongly influenced the coastal environment. This study used remotely sensed data to analyze the SS changes in coastal waters caused by the dyke construction. Landsat and MODIS satellite images were used for the spatial analysis of finer patterns and for the detailed temporal analysis, respectively. Forty Landsat scenes and 105 monthly composite MODIS images observed during 1985-2010 were employed, and four field campaigns (from 2005 to 2006) were performed to verify the image-derived SS. The results of the satellite data analyses showed that the seawater was clear before the dyke construction, with SS values lower than 20 g/m(3). These values increased continuously as the dyke construction progressed. The maximum SS values appeared just before completion of the fourth dyke. Values decreased to below 5 g/m(3) after dyke construction. These changes indicated tidal current modification. Some eddies and plumes were observed in the images generated from Landsat data. Landsat and MODIS can reveal that coastal water turbidity was greatly reduced after completion of the construction. PMID:22136763

Min, Jee-Eun; Ryu, Joo-Hyung; Lee, Seok; Son, Seunghyun

2011-12-02

360

Seismic expression of structural features on Landsat lineaments: an example from Denver basin  

Microsoft Academic Search

Lineaments interpreted from Landsat images mark the location and trend of basement faults observed on seismic lines in the eastern Denver basin. Linear features mapped as tone and texture patterns on multispectral scanner images in northeastern Colorado and southwestern Nebraska are used to interpret regional lineaments. Individual linear features up to 25 mi (40 km) long and visible on both

G. W. Shurr; J. T. Jr. Jenkins; D. M. Likarish

1985-01-01

361

Landsat Imagery: A Tool for Updating Land Use in Gulf Coast Mexico  

ERIC Educational Resources Information Center

|Explores the use of Landsat imagery in mapping and updating land use for the purpose of planning. Examines Gulf Coast Mexico as a case study, because modern agricultural techniques used to expand the ranching industry have significantly altered the landscape. (Author/BC)|

Harnapp, Vern

1978-01-01

362

Lithological discrimination using thermal inertia derived from Landsat TM data: a new algorithm proposed (TMTI)  

Microsoft Academic Search

The importance and the limits of the study of thermal inertia using Landsat TM data for lithological discrimination are here described. A new algorithm was developed to compute thermal inertia using monotemporal data, by combining values of the absorbed radiance (co- albedo) with those of the emitted radiance (thermal band), considering also bandwidths and calibration coefficients of the TM sensor.

Enzo Pranzini; Gaia Righini

1994-01-01

363

Regional forest growth rates measured by combining ICESat GLAS and Landsat data  

Microsoft Academic Search

Forest canopy heights derived from ICESat Geoscience Laser Altimeter System (GLAS) lidar data were combined with Landsat-based disturbance history maps to assess forest regeneration rates in three regions of the eastern United States (Maine, Virginia, and Mississippi). GLAS observations were screened for topographic relief and waveform quality, and canopy heights were obtained by visual inspection of each waveform. Regressing the

Katelyn Dolan; Jeffrey G. Masek; Chengquan Huang; Guoqing Sun

2009-01-01

364

Crop residue modeling and mapping using Landsat, ALI, hyperion and airborne remote sensing data  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various studies have demonstrated that spectral indices derived from Landsat TM data can be used effectively to quantify crop residue cover if adequately calibrated using in situ data. However, recent developments in remote sensing technologies may possibly accelerate research related to residue cov...

365

Utilization of LANDSAT-TM and SPOT multispectral raw and integrated data for land cover classification  

Microsoft Academic Search

The work of this dissertation presents results obtained from using LANDSAT-TM and SPOT multispectral raw and integrated image data for land cover\\/use classification with an emphasis on forest type discrimination. The main objective of this study was to find out to what degree information from satellites with different spectral and spatial resolution can be integrated and used to improve the

Dumitru Salajanu

1998-01-01

366

Zoom to Montana Fires Showing SeaWiFS Data and the Landsat-7 Thermal Channel  

NSDL National Science Digital Library

This animation shows the western fires burning in Montana. The initial frame is a SeaWiFS image showing the smoke plume stretching clear across the country. The camera zooms into the source of the fires, flying through the smoke plume, and revealing a composite image of visible and thermal Landsat7 data.

Mangos, Michael; Newcombe, Marte; Williams, Darrel

2000-07-28

367

Analysis of deforestation in Mato Grosso using multi-temporal Landsat TM Imageries  

Microsoft Academic Search

This paper summarizes the result of vegetation cover changes in Mato Grosso State in Amazonia, Central-West of Brazil. The study area is covered by Landsat TM Imagery Path 227 and Row 69, where soybean plantation spreads along the Highway BR 163. With the Global demand for biofuel, it recently became one of the main export crops in Brazil, causing large-scale

Megumi Maruyama; Yasushi Yamaguchi

2010-01-01

368

The Landsat Legacy: Remote Sensing Policy and the Development of Commercial Remote Sensing  

Microsoft Academic Search

This paper summarizes the policy history of Landsat and ex- amines its place in the development of land remote sensing for science, practical applications related to land use, and the marketplace. In particular, it identifies key steps in creat- ing the foundations for a commercial market in remotely sensed land data and information products. This paper fur- ther analyzes the

Ray A. Williamson

1997-01-01

369

Estimating Net Solar Radiation Using Landsat Thematic Mapper and Digital Elevation Data  

Microsoft Academic Search

A radiative transfer algorithm is combined with digital elevation and satellite reflectance data to model spatial variability in net solar radiation at fine spatial resolution. The method is applied to the tall-grass prairie of the 16 × 16 km2 FIFE site (First ISLSCP Field Experiment) of the International Satellite Land Surface Climatology Project. Spectral reflectances as measured by the Landsat

R. Dubayah

1992-01-01

370

Assessing the accuracy of Landsat Thematic Mapper classification using double sampling  

USGS Publications Warehouse

Double sampling was used to provide a cost efficient estimate of the accuracy of a Landsat Thematic Mapper (TM) classification map of a scene located in the Rocky Moutnain National Park, Colorado. In the first phase, 200 sample points were randomly selected to assess the accuracy between Landsat TM data and aerial photography. The overall accuracy and Kappa statistic were 49.5% and 32.5%, respectively. In the second phase, 25 sample points identified in the first phase were selected using stratified random sampling and located in the field. This information was used to correct for misclassification errors associated with the first phase samples. The overall accuracy and Kappa statistic increased to 59.6% and 45.6%, respectively.Double sampling was used to provide a cost efficient estimate of the accuracy of a Landsat Thematic Mapper (TM) classification map of a scene located in the Rocky Mountain National Park, Colorado. In the first phase, 200 sample points were randomly selected to assess the accuracy between Landsat TM data and aerial photography. The overall accuracy and Kappa statistic were 49.5 per cent and 32.5 per cent, respectively. In the second phase, 25 sample points identified in the first phase were selected using stratified random sampling and located in the field. This information was used to correct for misclassification errors associated with the first phase samples. The overall accuracy and Kappa statistic increased to 59.6 per cent and 45.6 per cent, respectively.

Kalkhan, M. A.; Reich, R. M.; Stohlgren, T. J.

1998-01-01

371

Mineral mapping and landsat thematic mapper image classification using spectral unmixing  

Microsoft Academic Search

In this paper, spectral image unmixing applied to Landsat Thematic mapper data from southern Spain is described to obtain a classified image based on abundance estimates of a number of spectral endmembers assuming linear mixing systematics. Spectral angle mapping (e.g. a technique by which a pixel spectrum is compared with a reference spectrum using the spectral angle between the two

Freek van der Meer

1997-01-01

372

Assessment of urban heat island and possible adaptations in Enugu urban using landsat-ETM  

Microsoft Academic Search

Urban heat Island (UHI) is the name given to the characteristic warmth of both the atmosphere and the lithosphere in cities (urban) compared to their rural (non-urbanized) surroundings. This study investi- gates the application of Landsat-ETM in the study of UHI. The study employed the normalized difference method to estimate Land Surface temperature (LST). The research assessed the level of

Enete Ifeanyi Christian; Tony Okolie

2009-01-01

373

Opportunities and difficulties associated with using Landsat Thematic Mapper data for determining surface water temperatures  

Microsoft Academic Search

This paper describes results of research efforts to estimate surface-water temperatures using Landsat 4 and 5 TM thermal band data. Recent research involved the analysis of day- and night-time TM Band 6 data in both corrected (P tape) and uncorrected (A tape) formats. Results reported are for (1) a reservoir reactor cooling system (PAR Pond) at the Department of Energy's

G. W. Wukelic; J. C. Barnard; G. M. Petrie; H. P. Foote

1985-01-01

374

APPLICATION OF MULTI-DATE LANDSAT 5 TIM IMAGERY FOR WETLAND IDENTIFICATION  

EPA Science Inventory

Multi-temporal Landsat 5 Thematic Mapper (TM) imagery was evaluated for the identification and monitoring of potential jurisdictional wetlands located in the states of Maryland and Delaware. A wetland map prepared from single-date TM imagery was compared to a hybrid map develope...

375

Modeling Suspended Solids Concentrations Based on TM/LANDSAT-5 Images at Guanabara Bay, Rj, Brazil.  

National Technical Information Service (NTIS)

A distribution of Total Suspended Solids (TSS) for Guanabara Bay is presented. The distribution was obtained through the expansion of a stepwise regression model that resulted from in situ and TM/LANDSAT-5 data. Water samples from 12 sites in the Bay were...

C. Z. F. Braga A. W. Setzer

1991-01-01

376

Estimating wetland vegetation biomass in the Poyang Lake of central China from Landsat ETM data  

Microsoft Academic Search

The estimation of the biomass of wetland vegetation is very important for wetland environment research. A method of rapidly estimating the biomass is discussed in this paper by using the combination of Remote Sensing, Geographic Information System (GIS) and Global Position System (GPS). By using Landsat ETM data of April 16,2000 and the field data investigated contemporaneously, the authors estimated

Li Rendong; Liu Jiyuan

2004-01-01

377

A procedure for regional lake water clarity assessment using Landsat multispectral data  

Microsoft Academic Search

Although previous investigations have demonstrated reliable empirical relationships between satellite data and nearly contemporaneous ground observations, satellite imagery has not been incorporated into routine lake monitoring programs. This paper focuses on key issues involved in applying satellite imagery to the regional assessment of lake clarity. Ten Landsat Thematic Mapper (TM) images and four Multispectral Scanner (MSS) images of the Twin

Steven M. Kloiber; Patrick L. Brezonik; Leif G. Olmanson; Marvin E. Bauer

2002-01-01

378

Design study of TDRS antenna gimbal system for LANDSAT-D  

Microsoft Academic Search

The conceptual design studies of a two axis antenna drive assembly for the TDRSS link communications subsystem for LANDSAT D are presented. The recommended antenna drive assembly is a simple and reliable design substantially similar to the antenna and solar array drives developed and space qualified for programs such as DSCS 2 and FltSatCom. The gimbal design tradeoff is presented,

J. Wu

1977-01-01

379

Estimation Of Leaf Area Index From Landsat Imagery For Texas High Plains Using Support Vector Machines  

Microsoft Academic Search

Leaf Area Index (LAI) is an important hydrologic parameter used for the estimation of evapotranspiration (ET) amongst other processes. Remote sensing provides an inexpensive and non-destructive tool in collecting LAI information on various spatial and temporal scales. In this study, we have developed models based on support vector machines (SVM) to estimate LAI using Landsat 5 Thematic Mapper (TM) data.

D. Misra; T. Oommen; P. H. Gowda; S. G. Bajwa; T. A. Howell

2008-01-01

380

Spectral characteristics of fire scars in Landsat5 TM images of Amazonia  

Microsoft Academic Search

This work describes spectral characteristics of fire scars in an area of intense deforestation in the Amazon tropical forest as recorded in the seven Landsat-5 TM spectral channels of an image in 1985. Ground covers were divided into four themes: natural forests, ‘capoeiras’, pastures in general and fire scars. Single-cell and maximum likelihood classification algorithms were used in the analysis.

M. C. PEREIRA; A. W. SETZER

1993-01-01

381

Chlorophyll distribution in Lake Kinneret determined from Landsat Thematic Mapper data  

Microsoft Academic Search

Chlorophyll distribution in Lake Kinneret was estimated at a time of low chlorophyll concentrations (3-7 mgm). Landsat Thematic Mapper (TM) data were acquired three days after the acquisition of high spectral resolution radiometric measurements in the range 400 to 750 nm, chlorophyll and suspended matter concentrations, and Secchi disk transparency at 22 stations. The radiometric data were used to create

M. Mayo; A. Gitelson; Y. Z. Yacobi; Z. Ben-Avraham

1995-01-01

382

Mapping deciduous forest ice storm damage using Landsat and environmental data  

Microsoft Academic Search

Sugar maple (Acer Saccharum Marsh.) damage resulting from a severe ice storm was modeled and mapped over eastern Ontario using pre- and post-storm Landsat 5 imagery and environmental data. Visual damage estimates in 104 plots and corresponding reflectance and environmental data were divided into multiple, mutually exclusive training and reference datasets for damage classification evaluation. Damage classification accuracy was compared

Ian Olthof; Douglas J. King; R. a. Lautenschlager

2004-01-01

383

Enhancing a Simple MODIS Cloud Mask Algorithm for the Landsat Data Continuity Mission.  

National Technical Information Service (NTIS)

The presence of clouds in images acquired by the Landsat series of satellites is usually an undesirable, but generally unavoidable fact. With the emphasis of the program being on land imaging, the suspended liquid/ice particles of which clouds are made of...

L. Oreopoulos M. J. Wilson

2011-01-01

384

Environmental characterization of a hypersaline coastal lagoon from Landsat5 Thematic Mapper data  

Microsoft Academic Search

Analysis of two 1994 Landsat-5 Thematic Mapper (TM) images (TM bands 1, 2, 3, 4 and 5) from a shallow coastal lagoon in Brazil yielded high correlations between the digitally processed upwelling radiances and synoptic field measurements of chlorophyll- a and Secchi disk depths in water depths greater than 3.5 m. However, in shallower water, bottom reflectance dominates the optical

C. Z. F. Braga; M. L. Vianna; B. Kjerfve

2003-01-01

385

Conversion of SRSC format LANDSAT tapes into VICAR compatible format VCF tapes  

NASA Astrophysics Data System (ADS)

Two computer programs used to convert computer compatible LANDSAT data tapes into a format compatible with the VICAR m image processing system installed at the CCS IBM 370/158 computer are described. This system requires 2400 foot, 9 track magnetic tape with 1600 bits per inch density.

Turner, B.

1981-06-01

386

Conversion of SRSC Format Landsat Tapes into VICAR Compatible Format VCF Tapes.  

National Technical Information Service (NTIS)

Two computer programs used to convert computer compatible LANDSAT data tapes into a format compatible with the VICAR m image processing system installed at the CCS IBM 370/158 computer are described. This system requires 2400 foot, 9 track magnetic tape w...

B. Turner

1981-01-01

387

Landsat: radiometric and topographic correction of satellite imagery (R package)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Most Geographic Information System software includes routines for atmospheric and topograhic correction of satellite imagery such as that taken by Landsat. Radiometric correction is an active area of research, and new, improved methods are rarely if ever available for testing and application. The R...

388

Faults in the Mojave Desert, California, as Revealed on Enhanced Landsat Images  

Microsoft Academic Search

Previously unknown strike-slip and normal faults in the central and eastern Mojave Desert have been revealed on Landsat Thematic Mapper images enhanced by fourcomponent processing. This method provides color images on which lithologies are discriminated by their contrasting absorption and reflection, primarily at infrared wavelengths and particularly with regard to their ferric iron, ferrous iron, and hydroxyl contents, while retaining

J. P. Ford; R. K. Dokka; R. E. Crippen; R. G. Blom

1990-01-01

389

Nonparametric analysis of LANDSAT maps using neural nets and parallel computers  

NASA Astrophysics Data System (ADS)

Nearest neighbor approaches and a new neural network, the Binary Diamond, are used for the classification of images of ground pixels obtained by LANDSAT satellite. The performances are evaluated by comparing classifications of a scene in the vicinity of Washington DC. The problem of optimal selection of categories is addressed as a step in the classification process.

Salu, Yehuda; Tilton, James C.

1992-04-01

390

Mapping and classification of Peatland on the Isle of Lewis using Landsat ETM+  

Microsoft Academic Search

Britain contains some of the largest areas of blanket peatland in the world and the monitoring of this resource is vital. This study has investigated whether Landsat ETM+ can be used to identify types of blanket peatland on Lewis. This was done using Principal Component Analysis (PCA) on composites of band ratios and single band variables, and using neural network

E. Brown; M. Aitkenhead; R. Wright; I. H. Aalders

2007-01-01

391

PROPORÇÃO DE COMPONENTES DERIVADAS DE IMAGENS LANDSAT TM PARA CARACTERIZAÇÃO DA COBERTURA DA TERRA NA AMAZÔNIA  

Microsoft Academic Search

Land conversion of forest to agricultural use, especially for the establishment of pasture contributes to the increasing of atmospheric CO2 concentration. Landsat Thematic Mapper imagery has potential to characterize land cover classes in the Amazon even in a subpixel basis if appropriate methods are used. This work had the objective to characterize several cover classes such as: forest, forest dominated

JORGE LUIS; GAVINA PEREIRA; GETULIO T. BATISTA; MARCELO CORDEIRO THALÊS; DAR A. ROBERTS

1998-01-01

392

Evaluation of Landsat7 ETM+ Panchromatic Band for Image Fusion with Multispectral Bands  

Microsoft Academic Search

The Landsat-7 ETM+ panchromatic band is taken simultaneously with multispectral bands using the same sensor system. The two data sets, therefore, are coregistered accurately and the solar illumination and other environmental conditions are identical. This makes ETM+ Pan advantageous to SPOT Pan for resolution fusion. A spectral preserve image fusion technique, Smoothing Filter-Based Intensity Modulation (SFIM), can produce optimal fusion

Jian Guo Liu

2000-01-01

393

Using the discrete wavelet frame transform to merge Landsat TM and SPOT panchromatic images  

Microsoft Academic Search

In this paper, we propose a pixel level image fusion algorithm for merging Landsat thematic mapper (TM) images and SPOT panchromatic images. The two source images are first decomposed using the discrete wavelet frame transform (DWFT), which is both aliasing free and translation invariant. Wavelet coefficients from TM's approximation subband and SPOT's detail subbands are then combined together, and the

Shutao Li; James T. Kwok; Yaonan Wang

2002-01-01

394

Overall Evaluation of LANDSAT (ERTS) Follow-on Imagery for Cartographic Application.  

National Technical Information Service (NTIS)

The author has identified the following significant results. The NASA/Cousteau experiment showed that under suitable conditions and with calibration data, the bottom of clear tropical seas can be mapped with Landsat to a depth of 22 meters with a root-mea...

A. P. Colvocoresses

1976-01-01

395

Magnetic Order of Three-Dimensional Transition Metal Overlayers on IRON(100): Vanadium, Chromium and Manganese  

NASA Astrophysics Data System (ADS)

Spin polarized electron energy loss spectroscopy (SPEELS) techniques were used to probe the surface magnetic state of thin epitaxial overlayers of V, Cr and Mn on the Fe(100) surface. These measurements were taken both as a function of electron energy loss and thickness of the overlayer film. The Cr overlayers were found to have a layer-by -layer antiferromagnetic arrangement very similar to that of bulk Cr and a surface enhanced magnetic moment of the order 2mu_{rm B}. This arrangement implies that the two monolayer coupling period oscillations observed in similar Fe/Cr/Fe sandwich systems are due to the magnetic ordering within the Cr spacer layer. The ordering of the Mn overlayers on Fe were found to have a layered antiferromagnetic ordering very similar to the Cr overlayer system. In comparison with the Cr/Fe system studies, this result implies that Fe/Mn/Fe sandwich systems should show couplings similar to the Fe/Cr/Fe system. The Mn overlayers on Fe(100) have a novel structure different from any bulk form. The measured surface moment of the order 2.9mu_{rm B} as well as the layered antiferromagnetic ordering compares well with theoretical calculations. V overlayers are found to be only weakly magnetic. Surface moments less than 1mu_{rm B} are found only for thicknesses less than 3 ML V. The 1 ML surface is antiferromagnetically aligned with the Fe surface, while the 2 ML surface aligns with the Fe. The surface moment for these systems is estimated at less than 1 mu_{rm B }. These results imply that the V/Ag system is also weakly magnetic, possibly resolving the controversy surrounding this system. The measurements of the V/Fe system compare well with calculations.

Walker, Theodore George

396

Simultaneous overlay and CD measurement for double patterning: scatterometry and RCWA approach  

NASA Astrophysics Data System (ADS)

As optical lithography advances to 32 nm technology node and beyond, double patterning technology (DPT) has emerged as an attractive solution to circumvent the fundamental optical limitations. DPT poses unique demands on critical dimension (CD) uniformity and overlay control, making the tolerance decrease much faster than the rate at which critical dimension shrinks. This, in turn, makes metrology even more challenging. In the past, multi-pad diffractionbased overlay (DBO) using empirical approach has been shown to be an effective approach to measure overlay error associated with double patterning [1]. In this method, registration errors for double patterning were extracted from specially designed diffraction targets (three or four pads for each direction); CD variation is assumed negligible within each group of adjacent pads and not addressed in the measurement. In another paper, encouraging results were reported with a first attempt at simultaneously extracting overlay and CD parameters using scatterometry [2]. In this work, we apply scatterometry with a rigorous coupled wave analysis (RCWA) approach to characterize two double-patterning processes: litho-etch-litho-etch (LELE) and litho-freeze-litho-etch (LFLE). The advantage of performing rigorous modeling is to reduce the number of pads within each measurement target, thus reducing space requirement and improving throughput, and simultaneously extract CD and overlay information. This method measures overlay errors and CDs by fitting the optical signals with spectra calculated from a model of the targets. Good correlation is obtained between the results from this method and that of several reference techniques, including empirical multi-pad DBO, CD-SEM, and IBO. We also perform total measurement uncertainty (TMU) analysis to evaluate the overall performance. We demonstrate that scatterometry provides a promising solution to meet the challenging overlay metrology requirement in DPT.

Li, Jie; Liu, Zhuan; Rabello, Silvio; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Park, Jungchul; Singh, Lovejeet

2009-03-01

397

Faster diffraction-based overlay measurements with smaller targets using 3D gratings  

NASA Astrophysics Data System (ADS)

Diffraction-based overlay (DBO) technologies have been developed to address the overlay metrology challenges for 22nm technology node and beyond. Most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. The traditional empirical approach (eDBO) using normal incidence spectroscopic reflectometry (NISR) relies on linear response of the reflectance with respect to overlay displacement within a small range. It offers convenience of quick recipe setup since there is no need to establish a model. However it requires three or four pads per direction (x or y) which adds burden to throughput and target size. Recent advances in modeling capability and computation power enabled mDBO, which allows overlay measurement with reduced number of pads, thus reducing measurement time and DBO target space. In this paper we evaluate the performance of single pad mDBO measurements using two 3D targets that have different grating shapes: squares in boxes and L-shapes in boxes. Good overlay sensitivities are observed for both targets. The correlation to programmed shifts and image-based overlay (IBO) is excellent. Despite the difference in shapes, the mDBO results are comparable for square and L-shape targets. The impact of process variations on overlay measurements is studied using a focus and exposure matrix (FEM) wafer. Although the FEM wafer has larger process variations, the correlation of mDBO results with IBO measurements is as good as the normal process wafer. We demonstrate the feasibility of single pad DBO measurements with faster throughput and smaller target size, which is particularly important in high volume manufacturing environment.

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Volkman, Catherine; Hu, Jiangtao

2012-03-01

398

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, July--September, 1994  

SciTech Connect

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. All eleven coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400 C and their erosion resistance was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. No correlations were found between room temperature hardness of the weld overlay coatings and their erosion resistance at elevated temperature. It was suggested that weld overlays mechanical properties such as fracture strength, toughness and work hardening rates may contributed to their erosion resistance. During the previous two quarters the microhardness tests were performed on the eroded samples in order to determine the size of the work hardened zone and the change in the coatings hardness due to erosion. As a result of these measurements it was established that one group of coatings deformed plastically, while another did not. In addition, the measurements of the weld overlays microhardness at 400 C were made. The coatings microhardness at 400 C was plotted versus their volume erosion rates. During the last quarter, erosion tests were performed for Inconel-625, 316L SS, and Iron-Aluminide wrought alloys in order to compare their erosion behavior with similar weld overlays. The results of microhardness profile measurements for all weld overlay coatings were analyzed. The factors that contribute to the erosion resistance of the coatings that deformed plastically are discussed in this progress report.

Levin, B.F.; Dupont, J.N.; Marder, A.R.

1994-10-26

399

Test of the use of LANDSAT imagery to detect changes in the area of forests in the tropics  

SciTech Connect

Rates of change in the area of tropical moist forest in the Brazilian State of Rondonia in the southwestern Amazon Basin were measured over several years using LANDSAT data. The purpose was to test in the tropics a technique of change detection developed in temperate forests. The entire procedure was tested from the availability of imagery on computer tapes through the details of the analysis. Imagery was available and obtained readily from the Brazilian Institute of Space Studies (INPE). Three LANDSAT scenes were used to detect and measure change: June 1976, August 1978 and May 1981. Results showed within the area of one LANDSAT scene (34,000 km/sup 2/) rates of deforestation of 26,900 ha/y from 1976 to 1978 and 55,200 ha/y from 1978 to 1981. The LANDSAT data were used with 1981 data from the NOAA7 satellite (1 km resolution) to show in a preliminary estimate that 12,650 km/sup 2/ of forest had been cleared in Rondonia prior to 1981. A survey of LANDSAT data available from tropical regions around the world showed that there is ample data for a LANDSAT-based evaluation of deforestation for the period 1972 to 1982 for Amazonia, Central Africa and mainland Southeast Asia. The evaluation of deforestation in insular Southeast Asia would be more difficult by LANDSAT currently due to high cloud cover in the region. 10 references, 10 figures, 2 tables.

Woodwell, G.M.; Hobbie, J.E.; Houghton, R.A.; Melillo, J.M.; Stone, T.A.

1983-09-01

400

The use of a new overlay mattress in patients with chronic pain: impact on sleep and self-reported pain  

Microsoft Academic Search

Objective: To evaluate the use of an air flotation mattress overlay in patients with chronic pain.Design: Four-week prospective AB design.Setting: The mattress overlay was used in a community setting.Subjects: Adult patients attending an outpatients clinic in a department of rheumatology, with chronic pain plus sleep problems, or pain sufficient to disturb sleep.Interventions: An inexpensive low-pressure inflatable mattress overlay (ReposeTM), which

P Price; S Rees-Mathews; N Tebble; J Camilleri

2003-01-01

401

An Application Example of the Landsat Data to the Study of the Relationship Between the Topography and Pasture Quality in Areas of Paragominas Exemplo de Aplicacao de Dados Do Sistema Landsat, No Estudo das Relacoes Entre Compartimentacao Topografica E Qualidade de Pastagens No Municipio de Paragominas (Pa).  

National Technical Information Service (NTIS)

The relationship between pasture quality and geomorphology was verified by applying visual and automatic interpretation techniques to LANDSAT data. The results show that LANDSAT data is useful to point out better areas to settle pastures.

N. Dejesusparada A. P. Dossantos E. M. L. Demoraesnovo V. Duarte

1980-01-01

402

Extraction of Suspended Sediments from Landsat Imagery in the Northern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

The Sediment Analysis Network for Decision Support (SANDS) project is utilizing enhancement methods to highlight suspended sediment in remotely sensed data and imagery of the Northern Gulf of Mexico. The analysis thus far has shown that areas of suspended sediments can be extracted from Landsat imagery. In addition, although not an original goal of SANDS, the analysis techniques have revealed oil floating on the water's surface. Detection of oil floating on the surface through remotely sensed imagery can be helpful in identifying and understanding the geographic distribution and movement of oil for environmental concerns. Data from Landsat, and MODIS were obtained from NASA Earth Science Data Centers by the Information Technology and Systems Center at the University of Alabama in Huntsville and prepared for analysis by subsetting to the region of interest and converting from HDF-EOS format (in the case of MODIS) to GeoTiff. Analysts at the Geological Survey of Alabama (GSA) working with Landsat data initially, employed enhancement methods, including false color composites, spectral ratios, and other spectral enhancements based on the mineral composition of sediments, to combinations of visible and infrared bands of data. Initial results of this approach revealed suspended sediments. The analysis technique also revealed areas of oil floating on the surface of the Gulf near Chandeleur Island immediately after Hurricane Katrina in 2005. True color Landsat imagery compares the original Landsat scene to the same region after enhancement. The areas of floating oil are clearly visible. The oil washed out from oil spills on land. This paper will present the intermediate result of the SANDS project thus far.

Hardin, D. M.; Drewry, M.; He, M. Y.; Ebersole, S.

2011-12-01

403

Landsat imagery-based water turbidity monitoring in Lake Paldang, Korea  

NASA Astrophysics Data System (ADS)

Turbid water of agricultural reservoir and downstream is getting worse and worse because the soil flows out from current residential land development and road construction. Sediment loads, which fill the water bodies (lakes, agricultural reservoir, dams, and aquatic ecosystems) are one of the most important environmental problems throughout the world. Water turbidity is a commonly used index of the factors that determine light penetration in the water column. Consistent estimation of water turbidity is crucial to design environmental and restoration management plans, to predict fate of possible pollutants, and to estimate sedimentary fluxes into the ocean. Traditional methods monitoring fixed geographical locations at fixed intervals may not be representative of the mean water turbidity in estuaries between intervals, and can be expensive and time consuming. Although remote sensing offers a good solution to this limitation, it is still not widely used due in part to required complex processing of imagery. The aims of this study were two folds: to map water turbidity and estimate water turbidity level based on Landsat imagery. Based on field measurements and principal component analysis (PCA), was examined the spatial variability of water turbidity in Lake Paldang by using the Landsat satellite imagery collected on 2001~2007. The result of this study is that when we carried out PCA using Landsat imagery, water turbidity had contributed at PC 2 which was similar to the in-situ data. A correlation formula (water turbidity = 0.3169 × PC2 - 21.477, R2 = 0.6319) between the in-situ data and PC2. And we can now use formula to map the water turbidity distribution from the synchronously acquired Landsat imagery, and continue the discussion on the inverse water turbidity results of the Landsat imagery. Because results from this type of study vary with season and time of day, it is necessary to monitor continuously in-situ data as well as radiance feature of reflectance in order to determine accurately the environmental factors of water quality.

Na, Sang-il; Park, Jin-ki; Baek, Shin-chul; Oh, Si-young; Park, Jong-hwa

2012-10-01

404

Infrared differential interference contrast microscopy for overlay metrology on 3D-interconnect bonded wafers  

NASA Astrophysics Data System (ADS)

Overlay metrology for stacked layers will be playing a key role in bringing 3D IC devices into manufacturing. However, such bonded wafer pairs present a metrology challenge for optical microscopy tools by the opaque nature of silicon. Using infrared microscopy, silicon wafers become transparent to the near-infrared (NIR) wavelengths of the electromagnetic spectrum, enabling metrology at the interface of bonded wafer pairs. Wafers can be bonded face to face (F2F) or face to back (F2B) which the stacking direction is dictated by how the stacks are carried in the process and functionality required. For example, Memory stacks tend to use F2B stacking enables a better managed design. Current commercial tools use single image technique for F2F bonding overlay measurement because depth of focus is sufficient to include both surfaces; and use multiple image techniques for F2B overlay measurement application for the depth of focus is no longer sufficient to include both stacked wafer surfaces. There is a need to specify the Z coordinate or stacking wafer number through the silicon when visiting measurement wafer sites. Two shown images are of the same (X, Y) but separate Z location acquired at focus position of each wafer surface containing overlay marks. Usually the top surface image is bright and clear; however, the bottom surface image is somewhat darker and noisier as an adhesive layer is used in between to bond the silicon wafers. Thus the top and bottom surface images are further processed to achieve similar brightness and noise level before merged for overlay measurement. This paper presents a special overlay measurement technique, using the infrared differential interference contrast (DIC) microscopy technique to measure the F2B wafer bonding overlay by a single shot image. A pair of thinned wafers at 50 and 150 ?m thickness is bonded on top of a carrier wafer to evaluate the bonding overlay. It works on the principle of interferometry to gain information about the optical path length of the stacked wafers, to enhance the image contrast of overlay marks features even though they are locating in different Z plane. A two dimensional mirror-symmetric overlay marks for both top and bottom processing wafers is designed and printed in each die in order to know and realize the best achievable wafer to wafer bonding processing. A self-developed analysis algorithms is used to identify the overlay error between the stacking wafers and the interconnect structures. The experimental overlay results after wafer bonding including inter-die and intra-die analysis results will be report in the full paper. Correlation of overlay alignment offset data to electrical yield, provides an early indication of bonded wafer yield.

Ku, Yi-sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung

2013-04-01

405

Diffraction-based overlay measurement on dedicated mark using rigorous modeling method  

NASA Astrophysics Data System (ADS)

Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

2012-03-01

406

Lateral root morphogenesis is dependent on the mechanical properties of the overlaying tissues  

PubMed Central

In Arabidopsis, lateral root primordia (LRPs) originate from pericycle cells located deep within the parental root and have to emerge through endodermal, cortical, and epidermal tissues. These overlaying tissues place biomechanical constraints on the LRPs that are likely to impact their morphogenesis. This study probes the interplay between the patterns of cell division, organ shape, and overlaying tissues on LRP morphogenesis by exploiting recent advances in live plant cell imaging and image analysis. Our 3D/4D image analysis revealed that early stage LRPs exhibit tangential divisions that create a ring of cells corralling a population of rapidly dividing cells at its center. The patterns of division in the latter population of cells during LRP morphogenesis are not stereotypical. In contrast, statistical analysis demonstrated that the shape of new LRPs is highly conserved. We tested the relative importance of cell division pattern versus overlaying tissues on LRP morphogenesis using mutant and transgenic approaches. The double mutant aurora1 (aur1) aur2 disrupts the pattern of LRP cell divisions and impacts its growth dynamics, yet the new organ’s dome shape remains normal. In contrast, manipulating the properties of overlaying tissues disrupted LRP morphogenesis. We conclude that the interaction with overlaying tissues, rather than the precise pattern of divisions, is most important for LRP morphogenesis and optimizes the process of lateral root emergence.

Lucas, Mikael; Kenobi, Kim; von Wangenheim, Daniel; Vo?, Ute; Swarup, Kamal; De Smet, Ive; Van Damme, Daniel; Lawrence, Tara; Peret, Benjamin; Moscardi, Eric; Barbeau, Daniel; Godin, Christophe; Salt, David; Guyomarc'h, Soazig; Stelzer, Ernst H. K.; Maizel, Alexis; Laplaze, Laurent; Bennett, Malcolm J.

2013-01-01

407

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1994--March 1994  

SciTech Connect

The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterwalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in circulated fluidized beds.

Levin, B.F.; Dupont, J.N.; Marder, A.R.

1994-04-21

408

The challenges of transitioning from linear to high-order overlay control in advanced lithography  

NASA Astrophysics Data System (ADS)

In the lithography section of the ITRS 2006 update, at the top of the list of difficult challenges appears the text "overlay of multiple exposures including mask image placement". This is a reflection of the fact that today overlay is becoming a major yield risk factor in semiconductor manufacturing. Historically, lithographers have achieved sufficient alignment accuracy and hence layer to layer overlay control by relying on models which define overlay as a linear function of the field and wafer coordinates. These linear terms were easily translated to correctibles in the available exposure tool degrees of freedom on the wafer and reticle stages. However, as the 45 nm half pitch node reaches production, exposure tool vendors have begun to make available, and lithographers have begun to utilize so called high order wafer and field control, in which either look up table or high order polynomial models are modified on a product by product basis. In this paper, the major challenges of this transition will be described. It will include characterization of the sources of variation which need to be controlled by these new models and the overlay and alignment sampling optimization problem which needs to be addressed, while maintaining the ever tightening demands on productivity and cost of ownership.

Adel, M.; Izikson, P.; Tien, D.; Huang, C. K.; Robinson, J. C.; Eichelberger, B.

2008-03-01

409

Effect of Palladium Overlayer on Samarium Hydride Thin Film Switchable Mirror: Electrochemical and Topographical Study  

NASA Astrophysics Data System (ADS)

Samarium films with a typical thickness of 55 nm deposited by vacuum evaporation and covered with Pd overlayers with thicknesses of 5, 8, 11, and 15 nm were loaded with hydrogen and deloaded in a 1 M KOH solution galvanostatically at room temperature. Our study showed that palladium overlayer thickness plays the most crucial role in observing the fast transition between an as-deposited metallic state and a semiconducting nearly samarium trihydride state as well as in obtaining a very high optical contrast. The desorption of hydrogen from palladium-capped SmH3-? films was studied by in situ transmission measurement during the electrochemical loading/unloading of hydrogen. It was shown that palladium cap layer thickness affects the deloading of hydrogen from the hydrided films. The effect of a palladium overlayer on the surface morphology of metallic and hydrogen-desorbed samarium films showed the sequence of nucleation and growth.

Kumar, Pushpendra; Malhotra, Lalit Kumar

2006-12-01

410

Weld overlay coatings for erosion control. Task A: Literature review, progress report  

SciTech Connect

A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

Levin, B.; DuPont, J.N.; Marder, A.R.

1993-03-03

411

Study of behaviors of aluminum overlayers deposited on uranium via AES, EELS, and XPS  

NASA Astrophysics Data System (ADS)

Aluminum overlayers on uranium were prepared by sputtering at room temperature in an ultra-high vacuum chamber. The growth mode of aluminum overlayers and behaviors of the Al/U interface reaction were studied in situ by auger electron spectroscopy, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy. The results suggested that the interdiffusion took place at the Al/U interface during the initial stage of deposition. The U4f spectra of the Al/U interface showed strong correlation satellites at binding energies of 380.4 and 392.7 eV and plasma loss features at 404.2 eV, respectively. The interactions between aluminum and uranium yielded the intermetallic compound of UAlx, inducing the shift to a low binding energy for Al2p peaks. The results indicated that aluminum overlayers were formed on the uranium by sputtering in an island growth mode.

Liu, Kezhao; Luo, Lizhu; Zhou, Wei; Yang, Jiangrong; Xiao, Hong; Hong, Zhanglian; Yang, Hui

2013-04-01

412

Web-enabled Landsat Data (WELD): Demonstration of MODIS-Landsat Data Fusion to Provide a Consistent, Long-term, Large-area Data Record for the Terrestrial User Community  

NASA Astrophysics Data System (ADS)

Consistent long-term and large-area Landsat data records are needed to monitor land cover change and study Earth system functioning. The objective of NASA’s Making Earth Science Data Records for Use in Research Environments (MEaSUREs) program is to provide Earth science data products and services driven by NASA’s Earth science goals and to advance NASA’s “missions to measurements” concept. This MEaSUREs WELD project contributes to the Land measurement theme by systematically generating radiometrically consistent Landsat Enhanced Thematic Mapper Plus (ETM+) mosaics of the conterminous USA (CONUS) and Alaska. The U.S. Department of Interior / U.S. Geological Survey (USGS) has been providing terrain-corrected Landsat ETM+ data at no cost since January 2008. In the WELD project every USGS Landsat ETM+ acquisition with cloud cover less than 60% is used to generate monthly, seasonal and annual composited mosaics. The consistency and quality of the ETM+ data is improved through a fusion with standard MODIS land products, including the MODIS BRDF reflectance anisotropy product to radiometrically normalize and fill missing (cloudy and SLC-off) Landsat pixels, the MODIS atmospheric characterization data to systematically atmospherically correct the Landsat data, and the MODIS vegetation continuous field product to provide training for Landsat scale land cover characterization. The WELD mosaics are defined at 30 m and include spectral reflectance, brightness temperature, normalized difference vegetation index, the date each composited pixel was acquired on, per-band radiometric saturation status, cloud mask values, and land cover characterization information. Results for the CONUS, algorithm insights, and information on how to access the WELD data products via the internet from the USGS Landsat project are presented.

Roy, D.; Ju, J.; Vermote, E. F.; Zhang, C.; Egorov, A.; Kovalskyy, V.; Loveland, T. R.; Hansen, M. C.; Scaramuzza, P. L.; Kline, K.; Yeom, J.; Kommadreddy, I.

2009-12-01

413

Comparison of Landsat MSS and TM imagery for long term forest land cover change assessment  

NASA Astrophysics Data System (ADS)

The main objective of this research is to determine forest cover change from 1975 to 2000 for a region in north Florida. In order to monitor long-term forest cover change for this project, Landsat MSS must be used with Landsat TM because Landsat MSS is the only datasets that is available for civilian use prior to the year of 1982. However, using these two different datasets in a project had been problematic and needed to be studied to obtain higher overall classification accuracy. Landsat MSS and TM classifications were achieved through a common approach. By increasing overall accuracy for both sensor types individually, images from these sensors will be more consistent. In order to achieve the main objective of this study, sixteen derived datasets were constructed and tested from March 24, 1986 Landsat MSS and Landsat TM imagery from the same area using low pass filtering, principal component Analysis (PCA), and tasseled cap transformation (TCT) to demonstrate the relationship between these two imageries. Similarities were 88.5% in best case. Results suggest that smoothing operations performed prior to classification improved the classification accuracy because they created a selection of homogeneous training sets. It was found that the smoothing operation performed prior to classification improved the classification accuracy by 7% compared to the original dataset classification. Performing the PCA and TCT to smoothed datasets also improved the classification accuracy by 4% compared to the smoothed datasets only. The first two principal components, PC1 and PC2, added to the first two indexes from TCT, BI and GI, were used to create new 4-band datasets for MSS and TM. These combinations of images were used to determine the forest land cover for the application site from the years 1975 to 2000. It was found that the determination of five land cover classes using these techniques produced moderate overall land cover classification accuracy ranging from 62.7% to 88.5%. However, this smoothing operation before classification created a selection of homogeneous training sets, which can result in the loss of some detail in the land cover classification. Therefore smoothing is not recommended for other studies unless it is required to improve the visualization and specific classes.

Genc, Levent

2003-10-01

414

Analyzing environmental policy change: United States Landsat policy, 1964--1998  

NASA Astrophysics Data System (ADS)

In recent years there has been an increase in the attention paid by policy scholars to the subject of policy change. Early attempts at studying this phenomena produced typologies of policy change and interesting case studies of specific instances of significant policy change. Recently, some policy scholars have worked to develop theoretical models of policy change that include explicit explanations of how and why public policies change over time. In general, scholars have identified two major sources of change: policy-oriented conflict and policy-oriented learning. One of the most advanced theoretical models of policy change is Sabatier and Jenkins-Smith's (1993, 1997) Advocacy Coalition Framework (ACF). This comprehensive theoretical model is at the forefront of policy change research because, among other things, it explicitly integrates both conflict and teaming as interdependent sources of policy change. This dissertation uses the case of changes in U.S. land remote sensing (Landsat) policy between 1964 and 1998 to demonstrate a combined qualitative/quantitative application of the ACF, test several of the ACF's key theoretical propositions, and generate a set of criteria for solidifying the policy subsystem concept. The first part of this study uses a detailed case-study of Landsat politics to demonstrate the emergence of this policy arena as a semi-autonomous policy subsystem from the larger U.S. science and technology policy domain during the 1970's and 80's. This case study also serves to illuminate the importance of policy-oriented conflict, policy-oriented learning, and exogenous events in influencing the significant policy changes that have occurred in U.S. Landsat policy over the last 35 years. The second part of this study uses historical data on the preferences of key Landsat policy elites (generated from the systematic content analysis of 163 testimonies, reports, and official statements), in combination with survey data collected on current Landsat policy preferences, to provide tests of several of the ACF's key theoretical propositions. The final chapter of this dissertation discusses the implications of the findings presented in Chapters 4--8 for the Landsat program, the Advocacy Coalition Framework, and the theory of public policy change.

Thomas, Gerald B.

415

Salish Kootenai College Student Internship With the Landsat Data Continuity Mission: A Student's Perspective  

NASA Astrophysics Data System (ADS)

Hello my name is Richard D. Fisher. I was very fortunate to be picked to travel to Washington DC in July 2004, to complete a five week internship at NASA. My internship project is located on the Flathead Reservation and the area is called the Jocko-Spring Creek. My project was to complete land cover classification and land cover change detection. In order for me to accomplish my goals I had to learn how to use two new computer programs, MultiSpec and ENVI (Environment for Viewing Images) for remote sensing processing. Computer use does not come easy to me because, I lack the training most people take for granted. However, I did not let this lack of training get me down. The first step was to acquire two Landsat images. The first image was from the Landsat 7, landsat satellite in 1999 and the other was from the Landsat 5 satellite in 1987. The path row for my study area is 41-27. Once the images were acquired I had to combine the different color bands to make one image and perform a blue band correction. The blue band correction takes the blue haze out of the images making them clearer. The visible bands are blue, green, red and three bands of infrared. Once these color bands are together you can change the color of the image to help you look for different features, because each different color band will show you something different. After I put the images together I used ENVI to do the land cover classifications. The next step was to subset my project area to a smaller size. I cut both images in exactly the same coordinates. With help from my NASA mentor scientist, Rich Irish from the Landsat Data Continuity Mission, and I used photo shop Adobe PhotoShop to do the subsetting of both images. We were able to then link the two images together using ENVI software. After that I started to analyze the different pixels and their colors. I classified each image starting with the areas I knew from the fieldwork. After the classifications on both images were complete and I felt confident in the final classification, I needed to work with the shadows from the mountains in the image. We performed change detection from subtracting the two images. These computer programs are fun to use and were very useful especially when combining Landsat images. I would recommend these programs to anyone.

Fisher, R.

2004-12-01

416

Data-driven simulations of the Landsat Data Continuity Mission (LDCM) platform  

NASA Astrophysics Data System (ADS)

The Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) are two new sensors being developed by the Landsat Data Continuity Mission (LDCM) that will extend over 35 years of archived Landsat data. In a departure from the whiskbroom design used by all previous generations of Landsat, the LDCM system will employ a pushbroom technology. Although the newly adopted modular array, pushbroom architecture has several advantages over the previous whiskbroom design, registration of the multi-spectral data products is a concern. In this paper, the Digital Imaging and Remote Sensing Image Generation (DIRSIG) tool was used to simulate an LDCM collection, which gives the team access to data that would not otherwise be available prior to launch. The DIRSIG model was used to simulate the two-instrument LDCM payload in order to study the geometric and radiometric impacts of the sensor design on the proposed processing chain. The Lake Tahoe area located in eastern California was chosen for this work because of its dramatic change in elevation, which was ideal for studying the geometric effects of the new Landsat sensor design. Multi-modal datasets were used to create the Lake Tahoe site model for use in DIRSIG. National Elevation Dataset (NED) data were used to create the digital elevation map (DEM) required by DIRSIG, QuickBird data were used to identify different material classes in the scene, and ASTER and Hyperion spectral data were used to assign radiometric properties to those classes. In order to model a realistic Landsat orbit in these simulations, orbital parameters were obtained from a Landsat 7 two-line element set and propagated with the SGP4 orbital position model. Line-of-sight vectors defining how the individual detector elements of the OLI and TIRS instruments project through the optics were measured and provided by NASA. Additionally, the relative spectral response functions for the 9 bands of OLI and the 2 bands of TIRS were measured and provided by NASA. The instruments were offset on the virtual satellite and data recorders used to generate ephemeris data for downstream processing. Finally, potential platform jitter spectra were measured and provided by NASA and incorporated into the simulations. Simulated imagery generated by the model was incrementally provided to the rest of the LDCM team in a spiral development cycle to constantly refine the simulations.

Gerace, Aaron; Gartley, Mike; Schott, John; Raqueño, Nina; Raqueño, Rolando

2011-05-01

417

The Use of Landsat Data for Evaluation and Characterization of Deforested Pastureland and Reforested Areas in Brazil.  

National Technical Information Service (NTIS)

The compatibility of using LANDSAT data for pastureland and reforestation studies was studied. The degradation of pastureland after deforestation was identified automatically using four indicators: the percentages of exposed soil, lateritic soil, types of...

P. H. Filho A. P. Dossantos E. M. L. Demoraesnovo Y. E. Shimabukuro V. Duarte

1980-01-01

418

Accuracy Assessment of 1992 Landsat-MSS Derived Land Cover for the Upper San Pedro Watershed (U.S./Mexico).  

National Technical Information Service (NTIS)

The utility of Digital Orthophoto Quads (DQQS) in assessing the classification accuracy of land cover derived from Landsat MSS data was investigated. Initially, the suitability of DOQs in distinguishing between different land cover classes was assessed us...

J. K. Maingi S. E. Kepner W. G. Edmonds

2002-01-01

419

LANDSAT monitoring of Lake Erie for phycocyanin content in cyanobacteria blooms from 06/2006-10/2007  

NASA Astrophysics Data System (ADS)

An algorithm for mapping phycocyanin content (PC) in lake water from LANDSAT TM satellite data was derived in the past from Western Lake Erie data for July 1, 2000, and found to be robust when applied to a withheld LANDSAT TM and in situ water data set for September 27, 2000 (Vincent et al, 2004). This same algorithm was applied to LANDSAT 5 data of Path 20 Row 31 (Toledo Frame) and Path 19 Row 31 (Cleveland Frame) in Western Lake Erie on overpass dates with less than 30 This work was funded by NOAA Contract Award NA06OAR4600197. Reference Vincent, R.K., X. Qin, R. M. L. McKay, J.Miner, K. Czajkowski, J. Savino, and T. Bridgeman, Phycocyanin Detection from LANDSAT TM Data for Mapping Cyanobacterial Blooms in Lake Erie, Remote Sensing of Environment, Vol. 89, No. 3, pp 381-392, 2004.

Vincent, Robert

420

Utilization of Landsat Multispectral Data in Geobotanical Investigations: The Location of Ironstone Gravel in the SAM Houston National Forest.  

National Technical Information Service (NTIS)

Practical techniques were developed and evaluated for deriving geobotanical information from LANDSAT MSS data acquired for a test site in the Sam Houston National Forest near Cleveland, Texas where gravel deposits exist in sufficient quantity that economi...

W. G. Cibula

1982-01-01

421

Use of Landsat MSS (Multispectral Scanner) Digital Data in Water Quality Mapping of the Neuse River Estuary, North Carolina.  

National Technical Information Service (NTIS)

Landsat multispectral scanner (MSS) digital data, and high resolution panoramic photography obtained from the Environmental Protection Agency's Enviropod were combined with surface measurements for water quality mapping of the Neuse River estuary, North C...

S. Khorram H. M. Cheshire

1983-01-01

422

Scalable Tool Infrastructure for the Cray XT Using Tree-Based Overlay Networks  

SciTech Connect

Performance, debugging, and administration tools are critical for the effective use of parallel computing platforms, but traditional tools have failed to overcome several problems that limit their scalability, such as communication between a large number of tool processes and the management and processing of the volume of data generated on a large number of compute nodes. A tree-based overlay network has proven effective for overcoming these challenges. In this paper, we present our experiences in bringing our MRNet tree-based overlay network infrastructure to the Cray XT platform, including a description of proof-of-concept tools that use MRNet on the Cray XT.

Roth, Philip C [ORNL; Vetter, Jeffrey S [ORNL

2009-01-01

423

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1993--March 1993  

SciTech Connect

Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

Levin, B.F.; Dupont, J.N.; Marder, A.R.

1993-04-18

424

Geometric Correction of SPOT and Landsat Imagery: A Comparison of Map and GPS-Derived Control Points  

Microsoft Academic Search

Problems arise with the geometric correction of satellite im- agery in areas where suitable topographic maps are not available. GPS technology is increasingly seen as a potential solution in such areas. In this study, the geometric correction of Landsat MSS (80-metre pixel), Landsat TM (30-metre pixel), and SPOT Panchromatic (1 0-metre pixel) satellife images was investigated using 1 :100,000-scale topographic

N. G. Kardoulas; A. I. Lawan

1996-01-01

425

An analysis of urban thermal characteristics and associated land cover in Tampa Bay and Las Vegas using Landsat satellite data  

Microsoft Academic Search

Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess urban area thermal characteristics in Tampa Bay watershed of west-central Florida, and the Las Vegas valley of southern Nevada. To quantitatively determine urban land use extents and development densities, sub-pixel impervious surface areas were mapped for both areas. The urban–rural boundaries and urban development densities

George Xian; Mike Crane

2006-01-01

426

FINDINGS ON THE USE OF LANDSAT-3 RETURN BEAM VIDICON IMAGERY FOR DETECTING LAND USE AND LAND COVER CHANGES.  

USGS Publications Warehouse

The spatial resolution of imagery from the return beam vidicon (RBV) camera aboard the Landsat-3 satellite suggested that such data might prove useful in inspecting land use and land cover maps. In this study, a 1972 land use and land cover map derived from aerial photographs is compared with a 1978 Landsat RBV image to delineate areas of change. Findings indicate RBV imagery useful in establishing the fact of change and in identifying gross category changes.

Milazzo, Valerie, A.

1983-01-01

427

Nanoparticles-modified polymer-based solar-reflective coating as a cooling overlay for asphalt pavement  

Microsoft Academic Search

The phenomenon of rutting is one of the most serious problems on asphalt pavements. Decreasing the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, a nano-sized-particles-filled polymer composite was developed as an overlay to reflect solar energy and decrease the surface temperature of asphalt pavements. The overlay

He Wang; Jing Zhong; Decheng Feng; Jing Meng; Ning Xie

2012-01-01

428

Evaluation of Iron Aluminide Weld Overlays for Erosion-Corrosion Resistant Boiler Tube Coatings in Low NOx Boilers  

SciTech Connect

Iron aluminide weld overlays containing ternary additions and thermal spray coatings are being investigated for corrosion protection of boiler tubes in Low NO{sub x} burners. The primary objective of the research is to identify overlay and thermal spray compositions that provide corrosion protection of waterwall boiler tubes.

Regina, J.R.; Lim, M.; Barbosa, N., DuPont, J.N.; Marder, A.R.

2000-04-28

429

C-arm Cone Beam Computed Tomographic Needle Path Overlay for Fluoroscopic-Guided Placement of Translumbar Central Venous Catheters  

SciTech Connect

C-arm cone beam computed tomography is an advanced 3D imaging technology that is currently available on state-of-the-art flat-panel-based angiography systems. The overlay of cross-sectional imaging information can now be integrated with real-time fluoroscopy. This overlay technology was used to guide the placement of three percutaneous translumbar inferior vena cava catheters.

Tam, Alda, E-mail: alda.tam@di.mdacc.tmc.ed [University of Texas M.D. Anderson Cancer Center, Division of Diagnostic Radiology, Section of Interventional Radiology, Unit 325 (United States); Mohamed, Ashraf [Siemens Corporate Research, Inc. (United States); Pfister, Marcus; Rohm, Esther [Siemens AG Healthcare Sector, AX Division (Germany); Wallace, Michael J. [University of Texas M.D. Anderson Cancer Center, Division of Diagnostic Radiology, Section of Interventional Radiology, Unit 325 (United States)

2009-07-15

430

Landsat digital data as tool for mining exploration and geologic mapping in coastal plain of Malaysian Peninsula  

SciTech Connect

Landsat Multispectral Scanner (MSS) data were used for systematic mapping of the coastal plain of the Malaysian Peninsula. The study was conducted to evaluate the use of Landsat digital data to assist the geologist in the exploration and mapping of the coastal plain of the Malaysian peninsula. The brightness of the four Landsat MSS channels and six ratios were recorded for each pixel, and were subsequently used as input to the supervised classification technique. Several lithologic units were selected to define training groups, and the remaining study area was classified into the preselected categories. The results indicated that using Landsat digital data combined with geologic and topographic information can improve the interpretation and quality of the geologic maps. The Landsat information was an effective tool to delineate the structural features and recognize different geologic patterns that can be defined as exploration targets. The most useful Landsat parameters to study the geology in the area were channels 5 and 7 and their ratio 7/5. Vegetation areas were enhanced by the ratio 6/4. Further field work in the area will confirm the results of the present study.

Prelat, A.E.

1986-07-01

431

16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...  

Code of Federal Regulations, 2010 CFR

...Overlay, Rolled Gold Plate, Silver, and Platinum Industry Products Appendix to Part...Overlay, Rolled Gold Plate, Silver, and Platinum Industry Products (a) Exemptions...considered in any assay for quality of a platinum industry product include...

2010-01-01

432

16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...  

Code of Federal Regulations, 2010 CFR

...Overlay, Rolled Gold Plate, Silver, and Platinum Industry Products Appendix to Part...Overlay, Rolled Gold Plate, Silver, and Platinum Industry Products (a) Exemptions...considered in any assay for quality of a platinum industry product include...

2009-01-01

433

Assessment of carbon storage and biomass on minelands reclaimed to grassland environments using Landsat spectral indices  

NASA Astrophysics Data System (ADS)

This study investigated carbon (C) storage and biomass in grasslands of West Virginia reclaimed surface minesites. Mine-related disturbance and subsequent reclamation may be an important component of C cycling. Biomass and C storage generally increased for the first five years after reclamation, but then declined, suggesting a nonlinear pattern to vegetation recovery. Three 2007 Landsat 5 Thematic Mapper and Landsat 7 Enhanced Thematic Mapper Plus images were used to assess the potential to predict biomass from raw red and near infrared radiance, the tasseled cap transformation (TC), and four vegetation indices [normalized difference vegetation index, enhanced vegetation index (EVI), triangular vegetation index, and the soil adjusted vegetation index]. TC greenness and EVI were most strongly correlated with biomass and illustrate a modest potential for monitoring vegetation recovery in reclaimed minelands. Additionally, a number of regression models that included age since reclamation and spectral indices were statistically significant suggesting a temporal recovery pattern amongst minesites in this study.

Kazar, Sheila A.; Warner, Timothy A.

2013-01-01

434

Pansharp vs. wavelet vs. PCA fusion technique for use with Landsat ETM panchromatic and multispectral data  

NASA Astrophysics Data System (ADS)

In this study we compare the efficiency of PCA, Pansharp and Wavelet fusion techniques for the fusion of Landsat ETM data. A Landsat 7 ETM cloud free subscene was used in this comparative study. The nearest neighborhood method has been used for the resampling and the fused images have a 15 meters pixel size. For each merged image we have examined: a) the optical qualitative result, using an ASTER vnir image with 15 meters resolution for comparison, b) the statistical parameters of the histograms of the various frequency bands, especially the standard deviation. All the fusion techniques improve the resolution and the optical result. The PCA merging technique seems better in discriminating between the coastal zone, the urban area and the rural area, maintains the natural colors but corrupts the statistical parameters. The Pansharp and the Wavelet merging technique give the best results without changing at all the statistical parameters of the original images.

Nikolakopoulos, Konstantinos G.

2004-11-01

435

DIGITAL PROCESSING TECHNIQUES FOR IMAGE MAPPING WITH LANDSAT TM AND SPOT SIMULATOR DATA.  

USGS Publications Warehouse

To overcome certain problems associated with the visual selection of Landsat TM bands for image mapping, the author used a quantitative technique that ranks the 20 possible three-band combinations based upon their information content. Standard deviations and correlation coefficients can be used to compute a value called the Optimum Index Factor (OIF) for each of the 20 possible combinations. SPOT simulator images were digitally processed and compared with Landsat-4 Thematic Mapper (TM) images covering a semi-arid region in northern Arizona and a highly vegetated urban area near Washington, D. C. Statistical comparisons indicate the more radiometric or color information exists in certain TM three-band combinations than in the three SPOT bands.

Chavez, Jr. , Pat, S.

1984-01-01

436

Commander field: Case study of a gas productive landsat and geochemical anomaly, Parker County, Texas  

SciTech Connect

Landsat data for a mature area of southern Parker County were analyzed for structural anomalies and lineaments in order to determine the relationship of these data to gas production and the possible fracturing of Atoka sand reservoirs. Interstitial soil gas data gathered over a 160 acre tract revealed a strong surface anomaly situated at the intersection of two lineaments. The drilling of this anomaly resulted in gas production from a Bend conglomerate and excellent mudlog shows of gas from shallower sands in the Atoka and Strawn intervals. A subsequent offset well, located within the original surface soil gas anomaly, also proved gas productive in the shallow Strawn interval. Well data from the productive gas zones are discussed in relation to local stratigraphy and structure. The limitations and advantages of Landsat/soil gas data are considered in terms of future applicability to other mature areas.

Crowder, W.T. Jr. [Consulting Geologist, Dallas, TX (United States)

1995-06-01

437

Artifact correction and absolute radiometric calibration techniques employed in the Landsat 7 image assessment system  

USGS Publications Warehouse

The Landsat-7 Image Assessment System (IAS), part of the Landsat-7 Ground System, will calibrate and evaluate the radiometric and geometric performance of the Enhanced Thematic Mapper Plus (ETM +) instrument. The IAS incorporates new instrument radiometric artifact correction and absolute radiometric calibration techniques which overcome some limitations to calibration accuracy inherent in historical calibration methods. Knowledge of ETM + instrument characteristics gleaned from analysis of archival Thematic Mapper in-flight data and from ETM + prelaunch tests allow the determination and quantification of the sources of instrument artifacts. This a priori knowledge will be utilized in IAS algorithms designed to minimize the effects of the noise sources before calibration, in both ETM + image and calibration data.

Boncyk, Wayne, C.; Markham, Brian, L.; Barker, John, L.; Helder, Dennis

1996-01-01

438

Application of Landsat thematic mapper to inlet dynamics, Old Drum Inlet, North Carolina  

Microsoft Academic Search

During the early morning hours of September 27, 1985, Hurricane Gloria crossed the North Carolina coast near Cape Hatteras, opening several new inlets on the Outer Banks barrier-island chain. Landsat thematic mapper (TM) imagery was used to watch the closure of one of the breaches, Old Drum Inlet, and to test the applicability of the TM sensor to small-scale, high-frequency

J. T. Wells; J. E. Camp

1987-01-01

439

A video system capable of simulating Landsat TM 5, 4, 3 imagery  

Microsoft Academic Search

This article describes a multispectral digital video imaging system that produces imagery similar to Landsat Thematic Mapper (TM) Bands 5, 4, 3. The system is comprised of two charge coupled device (CCD) analog video cameras, one tube analog video camera, and a computer equipped with an image digitizing board. The two CCD cameras are sensitive to visible\\/near-infrared wave-lengths and are

J. H. Everitt; D. E. Escobar; J. R. Noriega; I. Cavazos; M. R. Davis

1997-01-01

440

Lithological discrimination of Altun area in northwest China using Landsat TM data and geostatistical textural information  

Microsoft Academic Search

The image texture was extracted from Landsat TM data using rodogram, a geostatistical function, and then added to multispectral\\u000a classification for lithological discrimination of an arid region, the Altun Mountains in northwest China. The variogram analysis\\u000a of the image of the study area indicates that the image has two scales of textures: local and regional textures. Therefore,\\u000a two different window

Peijun Li; Zhengxiao Li; Wooil M. Moon

2001-01-01

441

Use of SRTM and Landsat7 to evaluate seismic hazards, Kodiak Island, Alaska  

Microsoft Academic Search

We have used SRTM and Landsat-7 digital data and paleoseismic techniques to identify active faults and evaluate seismic hazards on the northeast coast of Kodiak Island, Alaska. Kodiak Island is located in the eastern Aleutian subduction zone forearc and is above the down-dip limit of the great 1964 Prince William Sound earthquake (Mw 9.2) rupture segment. Along the north coast

G. Carver; J. Sauber; W. R. Lettis; R. C. Witter

2003-01-01

442

Velocity Fields on the Larsen C Ice Shelf, Antarctic Peninsula, Using Repeat MODIS and Landsat Data  

NASA Astrophysics Data System (ADS)

We investigate the velocity field of the Larsen C ice shelf, Antarctic Peninsula, over the periods 2002-2006 and 2006-2009 based on repeat optical satellite data. The velocity field of the entire ice shelf is measured using repeat low-resolution MODIS data (250 m). The measurements are validated for two ice-shelf sections against repeat medium-resolution Landsat 7 ETM+ pan data (15 m). Horizontal surface velocities are obtained through image matching in both frequency and spatial domain, and the two methods compared. The uncertainty in the velocities turns out to be less than 70 m for the MODIS-derived data, and less than 15 m for the Landsat-derived ones. The difference between MODIS and Landsat-based speeds is -15.4 m/a and 13.0 m/a for the first period for the two different validation sections on the ice shelf, and -26.7 m/a and 27.9 m/a for the second period for the same sections. This is within the uncertainty level, and leads us to conclude that repeat MODIS images are well suited to measure ice-shelf velocity fields and their changes over time. Frequency-domain image correlation methods seem better suited for this purpose because they are faster, produce less mis-matches, and are able to match images with regular noise and data voids. The latter makes it possible to match Landsat 7 ETM+ images even after the 2003 failure of the Scan Line Corrector (SLC off) that leaves significant image sections with no data.

Haug, T.; Kääb, A.; Skvarca, P.

2009-12-01

443

Downscaling of Aircraft, Landsat, and MODIS-based Land Surface Temperature Images with Support Vector Machines  

Microsoft Academic Search

High spatial resolution Land Surface Temperature (LST) images are required to estimate evapotranspiration (ET) at a field scale for irrigation scheduling purposes. Satellite sensors such as Landsat 5 Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) can offer images at several spectral bandwidths including visible, near-infrared (NIR), shortwave-infrared, and thermal-infrared (TIR). The TIR images usually have coarser spatial resolutions

W. Ha; P. H. Gowda; T. Oommen; T. A. Howell; J. E. Hernandez

2010-01-01

444

Location of kimberlites using Landsat Thematic Mapper images and aerial photographs: the Redondao diatreme, Brazil  

Microsoft Academic Search

Landsat Thematic Mapper images and aerial photographs were used in the detection of kimberlile-derived materials in the Redondao test site. In this area kimberlite-derived soils show a flora constituted mainly by grasses and shrubs, which differ from the surrounding savanna-park (cerrado) vegetation cover. Band-ratio images were able to distinguish kimberlite-derived materials by enhancing areas with different vegetation covers. However, the

R. Almeida-Filho; R. M. G. Castselo Branco

1992-01-01

445

The landsat data continuity mission operational land imager (OLI) radiometric calibration  

Microsoft Academic Search

The Operational Land Imager (OLI) on the Landsat Data Continuity Mission (LDCM) has a comprehensive radiometric characterization and calibration program beginning with the instrument design, and extending through integration and test, on-orbit operations and science data processing. Key instrument design features for radiometric calibration include dual solar diffusers and multi-lamped on-board calibrators. The radiometric calibration transfer procedure from NIST standards

Brian L. Markham; Philip W. Dabney; Jeanine E. Murphy-Morris; Jeffrey A. Pedelty; Edward J. Knight; Geir Kvaran; Julia A. Barsi

2010-01-01

446

Distribution of cloud-free Landsat images in the Barents region  

Microsoft Academic Search

The utility of optical satellites depends heavily on latitude and cloud cover. In the north-eastern corner of the Fenno-Scandinavian landmass, extreme seasonal variations in sunlight and the clashing of weather fronts severely limit the season for optical satellites. In this paper, we examine the distribution of cloud-free Landsat images of the Barents Region during 1984-93. Based on cloud-cover data from

Tore Tollefsen

1994-01-01

447

Lava flow cooling estimated from Landsat Thematic Mapper infrared data - The Lonquimay eruption (Chile, 1989)  

Microsoft Academic Search

Landsat TM data are used to measure the crust temperature and the fractional area for an active lava flow during the Lonquimay eruption. A progressive cooling of crusted lava from 250 to 170 C down a 1.5-km segment of the flow is shown. These results are obtained by solving 'dual-band' equations for the two short-wavelength infrared TM bands and by

Clive Oppenheimer

1991-01-01

448

Combination of Landsat TM and ERS-1 satellite data to discriminate forest cover types in Brazil  

NASA Astrophysics Data System (ADS)

The purpose of this study was to analyze the synergy between optical (Landsat TM) and microwave (ERS-1 satellite SAR) data sets, used singly and in combination, to discriminate and identify Eucalyptus stands and other cover types. The study site of interest is located in the vale do Rio Doce, State of Minas Gerais, Brazil. Reference data used in this study included detailed map and stand information (forest inventory data and management records). From the individual stand records, critical information such as cutting and planting dates were determined which show the age of the stands at the time both Landsat TM and ERS-1 radar data were obtained. The data sets were geometrically corrected, registered, and resampled to a 30 meter grid using cubic convolution interpolation. A maximum likelihood classifier was used in this study. The evaluation of the classifications was both qualitative and quantitative. Results indicated that the Landsat TM used alone was the most effective sensor system to classify Eucalyptus stands (accuracy of 94.8%), followed by the combined data set (accuracy of 85.9%). The combination of TM and ERS-1 data was generally not as effective as the use of Landsat alone, but did enable areas under clouds to be classified. The ERS-1 C-band radar data alone did not provide satisfactory results, with a classification accuracy of only 35.7%. This low accuracy was due, in part, to topographic effects. The use of ERS-1 SAR data appears to be severely limited in areas of rolling terrain, due to the variations in backscatter caused by the topographic effects.

Hoffer, Roger M.; Soares, Vicente P.

1995-01-01

449

Spatiotemporal dynamic of surface water bodies using Landsat time-series data from 1999 to 2011  

NASA Astrophysics Data System (ADS)

Detailed information on the spatiotemporal dynamic in surface water bodies is important for quantifying the effects of a drying climate, increased water abstraction and rapid urbanization on wetlands. The Swan Coastal Plain (SCP) with over 1500 wetlands is a global biodiversity hotspot located in the southwest of Western Australia, where more than 70% of the wetlands have been lost since European settlement. SCP is located in an area affected by recent climate change that also experiences rapid urban development and ground water abstraction. Landsat TM and ETM+ imagery from 1999 to 2011 has been used to automatically derive a spatially and temporally explicit time-series of surface water body extent on the SCP. A mapping method based on the Landsat data and a decision tree classification algorithm is described. Two generic classifiers were derived for the Landsat 5 and Landsat 7 data. Several landscape metrics were computed to summarize the intra and interannual patterns of surface water dynamic. Top of the atmosphere (TOA) reflectance of band 5 followed by TOA reflectance of bands 4 and 3 were the explanatory variables most important for mapping surface water bodies. Accuracy assessment yielded an overall classification accuracy of 96%, with 89% producer's accuracy and 93% user's accuracy of surface water bodies. The number, mean size, and total area of water bodies showed high seasonal variability with highest numbers in winter and lowest numbers in summer. The number of water bodies in winter increased until 2005 after which a decline can be noted. The lowest numbers occurred in 2010 which coincided with one of the years with the lowest rainfall in the area. Understanding the spatiotemporal dynamic of surface water bodies on the SCP constitutes the basis for understanding the effect of rainfall, water abstraction and urban development on water bodies in a spatially explicit way.

Tulbure, Mirela G.; Broich, Mark

2013-05-01

450

Landsat 7 - New York City Lithograph: Amelia's Adventures in New York City  

NSDL National Science Digital Library

This lithograph shows a Landsat 7 image of New York City and includes an activity for children ages 5-9. The imagery highlights vegetation, emphasizing location, with additional information, classroom activities or discus-shape and sizes of parks. The activity engages children in following Amelia the Pigeon's adventure around the parks in New York City. The lithograph is a companion piece to the Amelia the Pigeon Interactive Adventure (http://imagers.gsfc.nasa.gov/amelia).

2003-02-01

451

Evapotranspiration from Landsat (SEBAL) for water rights management and compliance with multi-state water compacts  

Microsoft Academic Search

SEBAL (Surface Energy Balance Algorithm for Land) is an image-processing model comprised of twenty-five computational submodels that calculates evapotranspiration (ET) and other energy exchanges at the Earth's surface. SEBAL uses digital image data collected by Landsat or other remote sensing satellites measuring thermal infrared radiation in addition to visible and near-infrared. SEBAL was originally developed in the Netherlands by Bastiaanssen

R. G. Allen; Anthony Morse; M. Tasumi; W. Bastiaanssen; W. Kramber; H. Anderson

2001-01-01

452

QWIP-based thermal infrared sensor for the Landsat Data Continuity Mission  

NASA Astrophysics Data System (ADS)

The thermal infrared sensor (TIRS) is a QWIP based instrument intended to supplement the Operational Land Imager (OLI) for the Landsat Data Continuity Mission (LDCM) [See Landsat project description at: http://landsathandbook.gsfc.nasa.gov/handbook/handbook_htmls/chapter1/chapter1.html, [1]. The LDCM is planned to be launched in late 2012 and will continue the 35 year legacy of the Landsat program as Landsat 7 degrades. The LDCM is a joint NASA-US Geological Survey (USGS) mission. The TIRS instrument is a far infrared imager operating in the push broom mode with two IR channels: 10.8 ?m and 12 ?m. The focal plane will contain three 640 × 512 QWIP arrays mounted on a silicon substrate. The readout integrated circuit (ROIC) is intended to be the Indigo 9803. The focal plane operating temperature will be 43 K (nominally). Bandpass filters will define the precise spectral response of the focal plane. Two QWIP designs will be pursued, the corrugated structure and the grating structure. NASA/Goddard, the Army Research Lab and QmagiQ will work closely together to obtain the suite of arrays that will best meet the mission requirements (primarily adequate conversion efficiency at the required wavelengths). This paper will describe the design and fabrication of the TIRS instrument with particular emphasis on the QWIP detectors. The QWIP parameters that are driving the mission requirements include spectral response, dark current, conversion efficiency, read noise, temperature stability, pixel uniformity and pixel yield. Additional mechanical constraints such as co-registration between the three arrays, filter design and assembly and testing will also be discussed.

Jhabvala, M.; Reuter, D.; Choi, K.; Jhabvala, C.; Sundaram, M.

2009-11-01

453

General characteristics and availability of Landsat 3 and heat capacity mapping mission thermal infrared data  

USGS Publications Warehouse

Two satellite systems launched by the National Aeronautics and Space Administration (NASA) in 1978 carried sensors which operated in the thermal infrared (IR) region of the electromagnetic spectrum, The final IR radiation data provide spectral information about the physical properties of the Earth's surficial materials not duplicated in either the visible or reflective IR wavelength regions. Landsat 3, launched on March 5, 1978, contained a thermal sensor as part of the multispectral scanner (MSS) system. The sensor operated in the 10.4- to 12.6-?m (band 8) wavelength region and produced imagery with a ground resolution of approximately 235 m. Launched on April 26) 1978) the Heat Capacity Mapping Mission (HCMM) spacecraft carried a sensor, the heat capacity mapping radiometer (HCMR) which operated in the 10.5- to 12.5?m wavelength region and produced imagery with a ground resolution of approximately 600 m at nadir. The HCMM satellite acquired over 6,600 data passes of visible (0.55-1.1 ?m), as well as thermal IR data, over North America, Europe, and Australia. General characteristics and availability of Landsat 3 and HCMM thermal IR data are discussed. Landsat 3 reflected IR band 7 (0.55-1.1 ?m) and Landsat 3 band 8 thermal data acquired over the eastern and western United States are analyzed and compared with HCMM visible, thermal IR, thermal inertia, and day-night temperature difference imagery for geologic applications. Digitally processed and enhanced HCMM data (high-pass filters, diagonal derivatives, and band ratios), produced by the U.S. Geological Survey, Flagstaff) Ariz., are presented for geologic interpretation.

Southworth, C. Scott

1983-01-01

454

Linear features determined from Landsat imagery in the Texas and Oklahoma panhandles  

USGS Publications Warehouse

A map (scale 1:500,000) shows the linear features determined from Landsat imagery in the Texas and Oklahoma panhandles. The linear features, sometimes called linear trends or lineaments, are not identified as to type or origin. Most probably represent fractures or fracture zones, which may affect the movement of water or other fluids through rocks. The linear features are classified as to length--less than 30 mi/mg and more than 30 mi/mg. (USGS)

Cooley, M. E.

1984-01-01

455

Mapping daily evapotranspiration at Landsat spatial scales during the BEAREX'08 field campaign  

NASA Astrophysics Data System (ADS)

Robust spatial information about environmental water use at field scales and daily to seasonal timesteps will benefit many applications in agriculture and water resource management. This information is particularly critical in arid climates where freshwater resources are limited or expensive, and groundwater supplies are being depleted at unsustainable rates to support irrigated agriculture as well as municipal and industrial uses. Gridded evapotranspiration (ET) information at field scales can be obtained periodically using land-surface temperature-based surface energy balance algorithms applied to moderate resolution satellite data from systems like Landsat, which collects thermal-band imagery every 16 days at a resolution of approximately 100 m. The challenge is in finding methods for interpolating between ET snapshots developed at the time of a clear-sky Landsat overpass to provide complete daily time-series over a growing season. This study examines the efficacy of a simple gap-filling algorithm designed for applications in data-sparse regions, which does not require local ground measurements of weather or rainfall, or estimates of soil texture. The algorithm relies on general conservation of the ratio between actual ET and a reference ET, generated from satellite insolation data and standard meteorological fields from a mesoscale model. The algorithm was tested with ET retrievals from the Atmosphere-Land Exchange Inverse (ALEXI) surface energy balance model and associated DisALEXI flux disaggregation technique, which uses Landsat-scale thermal imagery to reduce regional ALEXI maps to a finer spatial resolution. Daily ET at the Landsat scale was compared with lysimeter and eddy covariance flux measurements collected during the Bushland Evapotranspiration and Agricultural Remote sensing EXperiment of 2008 (BEAREX08), conducted in an irrigated agricultural area in the Texas Panhandle under highly advective conditions. The simple gap-filling algorithm performed reasonably at most sites, reproducing observed cumulative ET to within 5-10% over the growing period from emergence to peak biomass in both rainfed and irrigated fields.

Anderson, Martha C.; Kustas, William P.; Alfieri, Joseph G.; Gao, Feng; Hain, Christopher; Prueger, John H.; Evett, Steven; Colaizzi, Paul; Howell, Terry; Chávez, José L.

2012-12-01

456

Use of low cost Landsat ETM+ to spot burnt villages in Darfur, Sudan  

Microsoft Academic Search

A change detection analysis of Landsat ETM+ data from the conflict?affected area of Darfur Province in Sudan demonstrates that the recent (2003–2004) widespread burning of villages can be mapped with high accuracy (98.5% producer accuracy) at a much lower cost than other methods. By comparing albedo from two images with a 1 year interval, it was found that approximately half

E. Prins

2008-01-01

457

A new method to enhance the magnetism of Fe overlayer on GaAs(100): sulfur passivation using CH3CSNH2  

Microsoft Academic Search

Ferromagnetic resonance (FMR) has been used to investigat the magnetism of Fe overlayer on S-passivated GaAs(100) pretreated by CH3CSNH2. Comparing with the magnetism of Fe overlayer on clean GaAs(100), we find that sulfur passivation can prevent As diffusion into Fe overlayer and weaken the interaction of As and Fe. It results in enhancing the magnetism of Fe overlayer on GaAs(100).

Xu Peng-shou; Guo Hong-zhi; Zhang Fa-pei; Lu Er-dong; Xu Fa-qiang; Pan Hai-bin; Zhang Xin-yi

1999-01-01

458

Estimating aboveground biomass in interior Alaska with Landsat data and field measurements  

NASA Astrophysics Data System (ADS)

Terrestrial plant biomass is a key biophysical parameter required for understanding ecological systems in Alaska. An accurate estimation of biomass at a regional scale provides an important data input for ecological modeling in this region. In this study, we created an aboveground biomass (AGB) map at 30-m resolution for the Yukon Flats ecoregion of interior Alaska using Landsat data and field measurements. Tree, shrub, and herbaceous AGB data in both live and dead forms were collected in summers and autumns of 2009 and 2010. Using the Landsat-derived spectral variables and the field AGB data, we generated a regression model and applied this model to map AGB for the ecoregion. A 3-fold cross-validation indicated that the AGB estimates had a mean absolute error of 21.8 Mg/ha and a mean bias error of 5.2 Mg/ha. Additionally, we validated the mapping results using an airborne lidar dataset acquired for a portion of the ecoregion. We found a significant relationship between the lidar-derived canopy height and the Landsat-derived AGB (R2 = 0.40). The AGB map showed that 90% of the ecoregion had AGB values ranging from 10 Mg/ha to 134 Mg/ha. Vegetation types and fires were the primary factors controlling the spatial AGB patterns in this ecoregion.

Ji, Lei; Wylie, Bruce K.; Nossov, Dana R.; Peterson, Birgit; Waldrop, Mark P.; McFarland, Jack W.; Rover, Jennifer; Hollingsworth, Teresa N.

2012-08-01

459

Landsat as a Political Entity: Meaningful Communication for a National Asset  

NASA Astrophysics Data System (ADS)

Understanding the health of our planet on a global scale is essential to the world’s populace. Earth-observing satellites have long been collecting data that enable a robust comprehension of Earth’s complex and interconnected systems. Despite these important contributions, the fleet of U.S. Earth-observing satellites is aging and operational status for most onboard sensors has not materialized. These satellites are imperative objective viewers of our changing planet as we try to monitor and deal with natural disasters, carbon budgeting, water consumption, and food production. But the satellite building and launching process needed to sustain an operational observatory is extremely political. Landsat, the oldest civilian land-observing satellite, has a long and checkered political past, and it is only because of a handful of political champions that the program has endured. This begs the question: are policymakers aware of the contributions of satellites to our national wellbeing? And if not, can the science community better communicate with the general public at large and policy makers in particular? Here Landsat is examined as a political entity and the six pillars of effective science communication (context, trust, dialogue, clarity, respect, nuance) are used to develop, refine, and analyze a fact sheet and case study that explain the importance of Landsat Earth-observation to our society.

Rocchio, L. E.

2010-12-01

460

Estimating winter wheat biomass based on LANDSAT TM and MODIS data  

NASA Astrophysics Data System (ADS)

Biomass can indicate plant growth status, so it is an important index for plant growth monitoring. This paper focused on the methodology of estimating winter wheat biomass based on LANDSAT TM and EOS MODIS images. In order to develop the method of retrieving wheat biomass from remote sensing data, field measurements were conducted when LANDSAT satellite passed over the study region. In the experiments, five LANDSAT TM images were acquired respectively at early erecting stage, jointing stage, earing stage, flowering stage and grain-filling stage of winter wheat, and experiment sites' wheat biomass was measured at each stage. Based on the TM and MODIS images, spectral indices such as NDVI, RDVI, EVI, MSAVI, SIPI and NDWI were calculated. Then the correlation coefficients between wheat biomass and spectral indices of the experiment sites were computed. According to the correlation coefficients, the optimal spectral indices for estimating wheat biomass were determined. The best-fitting method was employed to build the relationship models between wheat biomass and the optimal spectral indices. Finally, the models were used to estimate wheat biomass based on TM and MODIS data. The RMSE of estimated biomass was not more than 66.403 g/m2.

Bao, Yansong; Gao, Wei; Gao, Zhiqiang

2008-08-01

461

A relation between landsat digital numbers, surface reflectance, and the cosine of the solar zenith angle  

USGS Publications Warehouse

A method for estimating the reflectance of ground sites from satellite radiance data is proposed and tested. The method uses the known ground reflectance from several sites and satellite data gathered over a wide range of solar zenith angles. The method was tested on each of 10 different Landsat images using 10 small sites in the Walker Lake, Nevada area. Plots of raw Landsat digital numbers (DNs) versus the cosine of the solar zenith angle (cos Z) for the the test areas are linear, and the average correlation coefficients of the data for Landsat bands 4, 5, 6, and 7 are 0.94, 0.93, 0.94, and 0.94, respectively. Ground reflectance values for the 10 sites are proportional to the slope of the DN versus cos Z relation at each site. The slope of the DN versus cos Z relation for seven additional sites in Nevada and California were used to estimate the ground reflectances of those sites. The estimates for nearby sites are in error by an average of 1.2% and more distant sites are in error by 5.1%. The method can successfully estimate the reflectance of sites outside the original scene, but extrapolation of the reflectance estimation equations to other areas may violate assumptions of atmospheric homogeneity. ?? 1982.

Kowalik, W. S.; Marsh, S. E.; Lyon, R. J. P.

1982-01-01

462

Evaluation and comparison of the IRS-P6 and the landsat sensors  

USGS Publications Warehouse

The Indian Remote Sensing Satellite (IRS-P6), also called ResourceSat-1, was launched in a polar sun-synchronous orbit on October 17, 2003. It carries three sensors: the highresolution Linear Imaging Self-Scanner (LISS-IV), the mediumresolution Linear Imaging Self-Scanner (LISS-III), and the Advanced Wide-Field Sensor (AWiFS). These three sensors provide images of different resolutions and coverage. To understand the absolute radiometric calibration accuracy of IRS-P6 AWiFS and LISS-III sensors, image pairs from these sensors were compared to images from the Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced TM Plus (ETM+) sensors. The approach involves calibration of surface observations based on image statistics from areas observed nearly simultaneously by the two sensors. This paper also evaluated the viability of data from these nextgeneration imagers for use in creating three National Land Cover Dataset (NLCD) products: land cover, percent tree canopy, and percent impervious surface. Individual products were consistent with previous studies but had slightly lower overall accuracies as compared to data from the Landsat sensors.

Chander, G.; Coan, M. J.; Scaramuzza, P. L.

2008-01-01

463

Preliminary on-orbit performance of the Thermal Infrared Sensor (TIRS) on board Landsat 8  

NASA Astrophysics Data System (ADS)

The Thermal Infrared Sensor (TIRS) on board Landsat 8 continues thermal band measurements of the Earth for the Landsat program. TIRS improves on previous Landsat designs by making use of a pushbroom sensor layout to collect data from the Earth in two spectral channels. The radiometric performance requirements of each detector were set to ensure the proper radiometric integrity of the instrument. The performance of TIRS was characterized during pre-flight thermal-vacuum testing. Calibration methods and algorithms were developed to translate the raw signal from the detectors into an accurate at-aperture spectral radiance. The TIRS instrument has the ability to view an on-board variable-temperature blackbody and a deep space view port for calibration purposes while operating on-orbit. After TIRS was successfully activated on-orbit, checks were performed on the instrument data to determine its image quality. These checkouts included an assessment of the on-board blackbody and deep space views as well as normal Earth scene collects. The calibration parameters that were determined pre-launch were updated by utilizing data from these preliminary on-orbit assessments. The TIRS on-orbit radiometric performance was then characterized using the updated calibration parameters. Although the characterization of the instrument is continually assessed over the lifetime of the mission, the preliminary results indicate that TIRS is meeting the noise and stability requirements while the pixel-to-pixel uniformity performance and the absolute radiometric performance require further study.

Montanaro, Matthew; Tesfaye, Zelalem; Lunsford, Allen; Wenny, Brian; Reuter, Dennis; Markham, Brian; Smith, Ramsey; Thome, Kurtis

2013-09-01

464

Four years of Landsat-7 on-orbit geometric calibration and performance  

USGS Publications Warehouse

Unlike its predecessors, Landsat-7 has undergone regular geometric and radiometric performance monitoring and calibration since launch in April 1999. This ongoing activity, which includes issuing quarterly updates to calibration parameters, has generated a wealth of geometric performance data over the four-year on-orbit period of operations. A suite of geometric characterization (measurement and evaluation procedures) and calibration (procedures to derive improved estimates of instrument parameters) methods are employed by the Landsat-7 Image Assessment System to maintain the geometric calibration and to track specific aspects of geometric performance. These include geodetic accuracy, band-to-band registration accuracy, and image-to-image registration accuracy. These characterization and calibration activities maintain image product geometric accuracy at a high level - by monitoring performance to determine when calibration is necessary, generating new calibration parameters, and verifying that new parameters achieve desired improvements in accuracy. Landsat-7 continues to meet and exceed all geometric accuracy requirements, although aging components have begun to affect performance.

Lee, D. S.; Storey, J. C.; Choate, M. J.; Hayes, R. W.

2004-01-01

465

Dark and background response stability for the Landsat 8 Thermal Infrared Sensor  

NASA Astrophysics Data System (ADS)

The Thermal Infrared Sensor (TIRS) is a pushbroom sensor that will be a part of the Landsat Data Continuity Mission (LDCM), which is a joint mission between NASA and the USGS. The TIRS instrument will continue to collect the thermal infrared data that are currently being collected by the Thematic Mapper and the Enhanced Thematic Mapper Plus on Landsats 5 and 7, respectively. One of the key requirements of the new sensor is that the dark and background response be stable to ensure proper data continuity from the legacy Landsat instruments. Pre launch testing of the instrument has recently been completed at the NASA Goddard Space Flight Center (GSFC), which included calibration collects that mimic those that will be performed on orbit. These collects include images of a cold plate meant to simulate the deep space calibration source as viewed by the instrument in flight. The data from these collects give insight into the stability of the instrument's dark and background response, as well as factors that may cause these responses to vary. This paper quantifies the measured background and dark response of TIRS as well as its stability.

Vanderwerff, Kelly; Montanaro, Matthew

2012-09-01

466

Automatic Generation of Overlays and Offset Values Based on Visiting Vehicle Telemetry and RWS Visuals.  

National Technical Information Service (NTIS)

The development of computer software as a tool to generate visual displays has led to an overall expansion of automated computer generated images in the aerospace industry. These visual overlays are generated by combining raw data with pre-existing data o...

M. J. Dunne

2011-01-01

467

Amniotic Membrane Inlay and Overlay Grafting for Corneal Epithelial Defects and Stromal Ulcers  

Microsoft Academic Search

Objectives: To determine the effect of amniotic mem- brane transplantation (AMT) on persistent corneal epi- thelial defects (PEDs) and to compare the efficacy be- tween inlay and overlay techniques. Methods: Thirty patients (30 eyes) underwent AMT for PED. The use of AMT was restricted to patients in whom all previous measures, including bandage contact lens and tarsorrhaphy, had failed. The

Erik Letko; Stephen U. Stechschulte; Kenneth R. Kenyon; Nadia Sadeq; Tatiana R. Romero; C. Michael Samson; Quan D. Nguyen; Stephanie L. Harper; Jonathan D. Primack; Dimitri T. Azar; Martin Gruterich; Claes H. Dohlman; Stefanos Baltatzis; C. Stephen Foster

2001-01-01

468

Overlay versus underlay myringoplasty: report of outcomes considering closure of perforation and hearing function.  

PubMed

In this series of patients, the underlay or overlay positioning of a graft achieves successful outcome for both repair of perforation and hearing function, with better hearing gain in the underlay group. In myringoplasty, the two most common techniques for positioning the graft relative to the remnant of both the tympanic membrane and the annulus are the "overlay" and the "underlay" techniques. 115 patients who underwent myringoplasty for tympanic membrane perforation secondary to chronic otitis media and/or trauma were included, and hearing function was evaluated. We prefer an overlay technique in subtotal perforations, in those involving the anterior and antero-inferior parts of the ear drum with respect to the handle of the malleus and in revision surgery. We reserve an underlay technique for smaller perforations and for those limited to the posterior part of the tympanic membrane. Of 115 cases, 63 underwent an overlay myringoplasty and 52 underlay myringoplasty. In the former group, five cases were anatomically unsuccessful, whereas in the second group there were three failures. The air bone gap improved significantly in both groups with a better hearing gain in the underlay group. PMID:22323847

Sergi, B; Galli, J; De Corso, E; Parrilla, C; Paludetti, G

2011-12-01

469

A Distributed Data Stream Management Model Based on Two-tier Overlay Network  

Microsoft Academic Search

In current distributed data stream management models, data should be transmitted on time among many computers through overlay network, which contains only logical topology information. For lack of real topology information, it is hard to control data delay. To solve this important problem, the requirement to process data stream in distributed networks is analyzed in this paper. Chord and super

Rong Xiao-xia; Wang Jin-dong

2006-01-01

470

Use of tile overlays to reduce the radiation efficiency of radiating surfaces  

Microsoft Academic Search

An intriguing possibility for reducing the radiation efficiency of a structure is to overlay its radiating surfaces with a contiguous set of low mass tiles. Experimental results show that significant reductions in sound power are possible depending on number of tiles, their geometry, attachment methods, mass, stiffness, and the amount of shear damping used to connect their edges to one

Gary Koopmann; Eric Salesky; Weicheng Chen

2002-01-01

471

Influence of overlay restorative materials and load cusps on the fatigue resistance of endodontically treated molars  

Microsoft Academic Search

Objectives: To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Method and Materials: Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL

Pascal Magne; Alena Knezevic

472

Dual Failure Protection in Multilayer Networks based on Overlay or Augmented Model  

Microsoft Academic Search

In this paper we present and compare different multilayer protection mechanisms which enable the client to protect its connections against dual failures in the server layer. In multilayer networks based on overlay or augmented model, the client is not aware of the routing information of the server layer. Therefore, some resilience mechanisms need new func- tions that have to be

473

Dual failure protection in multilayer networks based on overlay or augmented model  

Microsoft Academic Search

In this paper we present and compare different multilayer protection mechanisms which enable the client to protect its connections against dual failures in the server layer. In multilayer networks based on overlay or augmented model, the client is not aware of the routing information of the server layer. Therefore, some resilience mechanisms need new functions that have to be provided

Robert G. Prinz; A. Autenrieth; D. A. Schupke

2005-01-01

474

A study and simulation of the impact of high-order aberrations to overlay error distribution  

NASA Astrophysics Data System (ADS)

With reduction of design rules, a number of corresponding new technologies, such as i-HOPC, HOWA and DBO have been proposed and applied to eliminate overlay error. When these technologies are in use, any high-order error distribution needs to be clearly distinguished in order to remove the underlying causes. Lens aberrations are normally thought to mainly impact the Matching Machine Overlay (MMO). However, when using Image-Based overlay (IBO) measurement tools, aberrations become the dominant influence on single machine overlay (SMO) and even on stage repeatability performance. In this paper, several measurements of the error distributions of the lens of SMEE SSB600/10 prototype exposure tool are presented. Models that characterize the primary influence from lens magnification, high order distortion, coma aberration and telecentricity are shown. The contribution to stage repeatability (as measured with IBO tools) from the above errors was predicted with simulator and compared to experiments. Finally, the drift of every lens distortion that impact to SMO over several days was monitored and matched with the result of measurements.

Sun, G.; Wang, F.; Zhou, C.

2011-03-01

475

Reliable Routing of Event Notifications over P2P Overlay Routing Substrate in Event Based Middleware  

Microsoft Academic Search

Event broker networks(EBN) are a scalable incarna- tion of the publish subscribe paradigm for building asyn- chronous systems. These take the form of overlays of broker nodes and several routing schemes exist that deliver events from publishers to subscribers efficiently on different over- lay structures. However qualities of service based routing sche