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2001

University of New Hampshire

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Articles 1 - 30 of 45

Full-Text Articles in Physical Sciences and Mathematics

Seafloor Characterization From Spatial Variation Of Multibeam Backscatter Vs. Grazing Angle, Tianhang Hou, Lloyd C. Huff, Yuri Rzhanov, Larry A. Mayer Dec 2001

Seafloor Characterization From Spatial Variation Of Multibeam Backscatter Vs. Grazing Angle, Tianhang Hou, Lloyd C. Huff, Yuri Rzhanov, Larry A. Mayer

Center for Coastal and Ocean Mapping

Backscatter vs. grazing angle, which can be extracted from multibeam backscatter data, depend on characteristics of the multibeam system and the angular responses of backscatter that are characteristic of different seafloor properties, such as sediment hardness and roughness. Changes in backscatter vs. grazing angle that are contributed by the multibeam system normally remain fixed over both space and time. Therefore, they can readily be determined and removed from backscatter data. The variation of backscatter vs. grazing angle due to the properties of sediments will vary from location to location, as sediment type changes. The sediment component of variability can be …

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Improvement To The International Bathymetric Chart Of The Arctic Ocean (Ibcao): Updating The Data Base And The Grid Model, Martin Jakobsson, Norman Cherkis Dec 2001

Improvement To The International Bathymetric Chart Of The Arctic Ocean (Ibcao): Updating The Data Base And The Grid Model, Martin Jakobsson, Norman Cherkis

Center for Coastal and Ocean Mapping

The project to develop the IBCAO grid model was initiated in 1997 with the objective of providing to the Arctic research community an improved portrayal of the seabed north of 64-deg N, in a form suitable for digital manipulation and visualization. The model was constructed from a compilation of all single-beam and multibeam echo soundings that were available for the polar region, complemented where appropriate by newly released contour information. The grid features a cell size of 2.5 x 2.5 km on a polar stereographic projection; it is constructed on the WGS 84 datum, with true scale at 75-deg N. …

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Volumes And Areas Of Early Weichselian Ice Dammed Lakes In Northern Russia, Martin Jakobsson, Jan Mangerud, Valery Astakov, John Inge Svendsen Dec 2001

Volumes And Areas Of Early Weichselian Ice Dammed Lakes In Northern Russia, Martin Jakobsson, Jan Mangerud, Valery Astakov, John Inge Svendsen

Center for Coastal and Ocean Mapping

No abstract provided.

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Harmonising Chart And Navigation-Related Information On Ecdis, Lee Alexander Dec 2001

Harmonising Chart And Navigation-Related Information On Ecdis, Lee Alexander

Center for Coastal and Ocean Mapping

ECDIS is a real-time navigation system that integrates a variety of chart and navigation-related information. More than simply a replacement for a paper nautical chart, ECDIS is capable of continuously determining a vessel's position in relation to land, charted objects, aids-to-navigation, and unseen hazards. Increasingly, ECDIS is being used for both navigation and collision-avoidance tasks. There is growing concern about the display of ever-increasing amounts of both chart and navigation-related information. When it comes to using ECDIS, displaying more information is not necessarily better. Too much information (i.e., clutter) may only lead to confusion. In this regard, there is need …

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Hypsometry And Volume Of The Arctic Ocean And Its Constituent's Seas, Martin Jakobsson Nov 2001

Hypsometry And Volume Of The Arctic Ocean And Its Constituent's Seas, Martin Jakobsson

Center for Coastal and Ocean Mapping

No abstract provided.

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Ecdis Development Laboratory And Navigation Technology Demonstration Center, Lee Alexander, Maxim F. Van Norden, Charles M. Fralick Nov 2001

Ecdis Development Laboratory And Navigation Technology Demonstration Center, Lee Alexander, Maxim F. Van Norden, Charles M. Fralick

Center for Coastal and Ocean Mapping

The U.S. Navy is undergoing a major transition from traditional, paper chart navigation to computer-based electronic charting. The Chief of Naval Operations (CNO) has mandated that all Navy ships will navigate strictly through electronic means by FY07. However, due to some recent groundings, the Navy is now striving to accelerate the full implementation of electronic navigation by FY04. The Naval Oceanographic Office (NAVOCEANO) is making a concerted effort to support this transition with upgrades to state-of-the-art survey ships, instrumentation, and data processing equipment. NAVOCEANO is increasing its capability to rapidly collect and process hydrographic survey data, and to quickly produce …

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Field Evaluation Of Sounding Accuracy In Deep Water Multibeam Swath Bathymetry, Christian De Moustier Nov 2001

Field Evaluation Of Sounding Accuracy In Deep Water Multibeam Swath Bathymetry, Christian De Moustier

Center for Coastal and Ocean Mapping

A new Kongsberg-Simrad EM120 multibeam echo-sounder has been installed aboard Scripps Institution of Oceanography's Research Vessel Roger Revelle in January 2001. This system can map reliably a 20 km swath of seafloor in 4000 m water depth with 191 soundings per ping. Such a wide swath width demands highly accurate (<0.05' RMS) roll information from a motion sensor, and makes estimating sounding accuracy across the swath an interesting challenge. It is shown that good accuracy estimates can be obtained by collecting data on station under control of the GPS-aided dynamic positioning system usually available on most modern long-range oceanographic vessels. A number of motion sensors, with RMS roll accuracy specifications ranging from 0.05' to 0.01' ,were tested with the EM120 sonar on station in 3800 m to 4000 m water depths. Unexpectedly, they yielded roughly the same depth uncertainty as a function of receive beam angle. This result might be explained by synchronization errors between the attitude data and the sonar data leading to beam pointing errors, other types of beam pointing errors, a range of roll accuracy narrower than specified for the motion sensors, or a combination of these factors

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Geozui3d: Data Fusion For Interpreting Oceanographic Data, Colin Ware, Matthew D. Plumlee, Roland J. Arsenault, Larry A. Mayer, Shep M. Smith Lt, Donald H. House Nov 2001

Geozui3d: Data Fusion For Interpreting Oceanographic Data, Colin Ware, Matthew D. Plumlee, Roland J. Arsenault, Larry A. Mayer, Shep M. Smith Lt, Donald H. House

Center for Coastal and Ocean Mapping

GeoZui3D stands for Geographic Zooming User Interface. It is a new visualization software system designed for interpreting multiple sources of 3D data. The system supports gridded terrain models, triangular meshes, curtain plots, and a number of other display objects. A novel center of workspace interaction method unifies a number of aspects of the interface. It creates a simple viewpoint control method, it helps link multiple views, and is ideal for stereoscopic viewing. GeoZui3D has a number of features to support real-time input. Through a CORBA interface external entities can influence the position and state of objects in the display. Extra …

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Derivation Of Del180 From Sediment Core Log Data' Implications For Millennial-Scale Climate Change In The Labrador Sea, M. E. Weber, Larry A. Mayer, C. Hillaire-Marcel, G. Bilodeau, F. Rack, R. N. Hiscott, A. E. Aksu Oct 2001

Derivation Of Del180 From Sediment Core Log Data' Implications For Millennial-Scale Climate Change In The Labrador Sea, M. E. Weber, Larry A. Mayer, C. Hillaire-Marcel, G. Bilodeau, F. Rack, R. N. Hiscott, A. E. Aksu

Center for Coastal and Ocean Mapping

Sediment core logs from six sediment cores in the Labrador Sea show millennial-scale climate variability during the last glacial by recording all Heinrich events and several major Dansgaard-Oeschger cycles. The same millennial-scale climate change is documented for surface water δ18O records of Neogloboquadrina pachyderma (left coiled); hence the surface water δ18O record can be derived from sediment core logging by means of multiple linear regression, providing a paleoclimate proxy record at very high temporal resolution (70 years). For the Labrador Sea, sediment core logs contain important information about deepwater current velocities and also reflect the variable …

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Sensor-Assisted Video Mosaicing For Seafloor Mapping, Yuri Rzhanov, Randy G. Cutter Jr., Lloyd C. Huff Oct 2001

Sensor-Assisted Video Mosaicing For Seafloor Mapping, Yuri Rzhanov, Randy G. Cutter Jr., Lloyd C. Huff

Center for Coastal and Ocean Mapping

This paper discusses a proposed processing technique for combining video imagery with auxiliary sensor information. The latter greatly simplifies image processing by reducing complexity of the transformation model. The mosaics produced by this technique are adequate for many applications, in particular habitat mapping. The algorithm is demonstrated through simulations and hardware configuration is described.

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Relationships Between Synoptic-Scale Transport And Interannual Variability Of Inorganic Cations In Surface Snow At Summit, Greenland: 1992-1996, J F. Slater, Jack E. Dibb, Barry D. Keim, D W. Kahl Sep 2001

Relationships Between Synoptic-Scale Transport And Interannual Variability Of Inorganic Cations In Surface Snow At Summit, Greenland: 1992-1996, J F. Slater, Jack E. Dibb, Barry D. Keim, D W. Kahl

Earth Sciences

To fully utilize the long-term chemical records retrieved from central Greenland ice cores, specific relationships between atmospheric circulation and the variability of chemical species in the records need to be better understood. This research examines associations between the variability of surface snow inorganic cation chemistry at Summit, Greenland (collected during 1992–1996 summer field seasons) and changes in air mass transport pathways and source regions, as well as variations in aerosol source strength. Transport patterns and source regions are determined through 10-day isentropic backward air mass trajectories during a 1 month (late May to late June) common season over the 5 …

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Mev Magnetosheath Ions Energized At The Bow Shock, S. Chang, J. D. Scudder, K. Kudela, Harlan E. Spence, J. F. Fennell, R. P. Lepping, R. P. Lin, C. T. Russell Sep 2001

Mev Magnetosheath Ions Energized At The Bow Shock, S. Chang, J. D. Scudder, K. Kudela, Harlan E. Spence, J. F. Fennell, R. P. Lepping, R. P. Lin, C. T. Russell

Physics & Astronomy

A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV e−1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions …

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Table Of Contents Volume 12, Number 3/4, Fall 2001, Risk Editorial Board Sep 2001

Table Of Contents Volume 12, Number 3/4, Fall 2001, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Public Reaction To Mandated Language For U.S. Drinking Water Quality Reports, Branden B. Johnson Sep 2001

Public Reaction To Mandated Language For U.S. Drinking Water Quality Reports, Branden B. Johnson

RISK: Health, Safety & Environment (1990-2002)

The author discusses results of a survey evaluating the mandated language for United States drinking water quality reports.

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Review Of: Social Trust And The Management Of Risk (George Cvetkovich & Ragnar E. Loftstedt, Eds.), Mahua Roy Chowdhury Sep 2001

Review Of: Social Trust And The Management Of Risk (George Cvetkovich & Ragnar E. Loftstedt, Eds.), Mahua Roy Chowdhury

RISK: Health, Safety & Environment (1990-2002)

Review of the book: Social Trust and the Management of Risk (George Cvetkovich & Ragnar E. Löfstedt, eds., Earthscan Publications Ltd. 1999). Tables, Figures, and Boxes, Acronyms and Abbreviations, Forward, Preface, Introduction, References, Index. ISBN 1-85383-604-4 [196 pp. $25.00. Paperback, 120 Pentonville Road, London, NI 9JN UK].

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Journalists' Views Of The Environment: Issues And Challenges, Bernadette West, Jane Lewis, Michael Greenberg Sep 2001

Journalists' Views Of The Environment: Issues And Challenges, Bernadette West, Jane Lewis, Michael Greenberg

RISK: Health, Safety & Environment (1990-2002)

In advocating the use of an environmental handbook for journalists, the authors report on a survey of reporters and editors regarding salient environmental issues in different regions of the United States and e emphasis placed on environmental reporting in newsrooms.

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Review Of: Eckard Kämper, Decision Making Under Risk In Organisations: The Case Of German Waste Management, Jeremy S. Cleverly Sep 2001

Review Of: Eckard Kämper, Decision Making Under Risk In Organisations: The Case Of German Waste Management, Jeremy S. Cleverly

RISK: Health, Safety & Environment (1990-2002)

Review of the book: Eckard K-Kämper, Decision Making Under Risk in Organisations: The Case of German Waste Management (Ashgate Publishing Co. 2000). Preface, Acknowledgements, Bibliography. ISBN 0-7546-1434-4 [183 pp. $69.95. Hardbound, 131 Main Street, Burlington, VT 05401- 5600].

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Improvement Of Image Alignment Using Camera Attitude Information, Yuri Rzhanov, Lloyd C. Huff, Randy G. Cutter Jr. Aug 2001

Improvement Of Image Alignment Using Camera Attitude Information, Yuri Rzhanov, Lloyd C. Huff, Randy G. Cutter Jr.

Center for Coastal and Ocean Mapping

We discuss a proposed technique for incorporation of information from a variety of sensors in a video imagery processing pipeline. The auxiliary information allows one to simplify computations, effectively reducing the number of independent parameters in the transformation model. The mosaics produced by this technique are adequate for many applications, in particular habitat mapping. The algorithm, demonstrated through simulations and hardware configuration, is described in detail

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Anatomy Of A Community-Level Fiscal Impact Model: Fit-4-Nh., Tracey L. Farrigan, John M. Halstead, Martin L. Shields, Douglas E. Morris, Edmund F. Jansen Jr Jul 2001

Anatomy Of A Community-Level Fiscal Impact Model: Fit-4-Nh., Tracey L. Farrigan, John M. Halstead, Martin L. Shields, Douglas E. Morris, Edmund F. Jansen Jr

Natural Resources & the Environment

Abstract: This paper describes the development of a fiscal impact tool for New Hampshire communities (HT -4-NH). FIT -4-NH belongs to a family of computergenerated fiscal impact assessment models designed to estimate the impacts to local government revenues and expenditures that result from economic changes. In the past, work in this area has centered on the completion of countylevel models for the midwestern states. FIT-4-NH is unique in that it was designed for rural community-level use in the northern New England region of the country.

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Moving Icons, Detection And Distraction, Lyn Bartram, Colin Ware, Tom Calvert Jul 2001

Moving Icons, Detection And Distraction, Lyn Bartram, Colin Ware, Tom Calvert

Center for Coastal and Ocean Mapping

Simple motion has great potential for visually encoding information but there are as yet few experimentally validated guidelines for its use. Two studies were carried out to look at how efficiently simple motion cues were detected and how distracting they were in different task contexts. The results show that motion outperforms static representations and identify certain types of motions which are more distracting and irritating than others.

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Error Estimation Of Bathymetric Grid Models Derived From Historic And Contemporary Data Sets, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong May 2001

Error Estimation Of Bathymetric Grid Models Derived From Historic And Contemporary Data Sets, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

The past century has seen remarkable advances in technologies associated with positioning and the measurement of depth. Lead lines have given way to single beam echo sounders, which in turn are being replaced by multibeam sonars and other means of remotely and rapidly collecting dense bathymetric datasets. Sextants were replaced by radio navigation, then transit satellite, GPS and now differential GPS. With each new advance comes tremendous improvement in the accuracy and resolution of the data we collect. Given these changes and given the vastness of the ocean areas we must map, the charts we produce are mainly compilations of …

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Automatic Detection Of Outliers In Multibeam Echo Sounding Data, Tianhang Hou, Lloyd C. Huff, Larry A. Mayer May 2001

Automatic Detection Of Outliers In Multibeam Echo Sounding Data, Tianhang Hou, Lloyd C. Huff, Larry A. Mayer

Center for Coastal and Ocean Mapping

The data volumes produced by new generation multibeam systems are very large, especially for shallow water systems. Results from recent multibeam surveys indicate that the ratio of the field survey time, to the time used in interactive editing through graphical editing tools, is about 1:1. An important reason for the large amount of processing time is that users subjectively decide which soundings are outliers. There is an apparent need for an automated approach for detecting outliers that would reduce the extensive labor and obtain consistent results from the multibeam data cleaning process, independent of the individual that has processed the …

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Robust Automatic Multi-Beam Bathymetric Processing, Brian R. Calder, Larry A. Mayer May 2001

Robust Automatic Multi-Beam Bathymetric Processing, Brian R. Calder, Larry A. Mayer

Center for Coastal and Ocean Mapping

No abstract provided.

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Table Of Contents Volume 12, Number 1/2, Spring 2001, Risk Editorial Board Mar 2001

Table Of Contents Volume 12, Number 1/2, Spring 2001, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Cross-Shelf Eddy Heat Transport In A Wind-Free Coastal Ocean Undergoing Winter Time Cooling, James M. Pringle Feb 2001

Cross-Shelf Eddy Heat Transport In A Wind-Free Coastal Ocean Undergoing Winter Time Cooling, James M. Pringle

Earth Sciences

A steady state cross-shelf density gradient of a wind-free coastal ocean undergoing winter time cooling is found for cooling and geometries which do not vary in the along-shelf direction. The steady state cross-shelf density gradient exists even when the average density of the water continues to increase. The steady state density gradient dan be attained in less than a winter for parameters appropriate to the mid-Atlantic Eight. The cross-shelf eddy-driven buoyancy fluxes which cause this steady state gradient are found to depend critically on bottom friction and bottom slope, and the coastal polyna solutions of Chapman and Gawarkiewicz [1997] are …

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Charge Exchange Contribution To The Decay Of The Ring Current, Measured By Energetic Neutral Atoms (Enas), A. M. Jorgensen, M. G. Henderson, E. C. Roelof, G. D. Reeves, Harlan E. Spence Feb 2001

Charge Exchange Contribution To The Decay Of The Ring Current, Measured By Energetic Neutral Atoms (Enas), A. M. Jorgensen, M. G. Henderson, E. C. Roelof, G. D. Reeves, Harlan E. Spence

Physics & Astronomy

In this paper we calculate the contribution of charge exchange to the decay of the ring current. Past works have suggested that charge exchange of ring current protons is primarily responsible for the decay of the ring current during the late recovery phase, but there is still much debate about the fast decay of the early recovery phase. We use energetic neutral atom (ENA) measurements from Polar to calculate the total ENA energy escape. To get the total ENA escape we apply a forward modeling technique, and to estimate the total ring current energy escape we use the Dessler-Parker-Sckopke relationship. …

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Geographic Information Systems Tools For Collecting And Accessing Arctic Bathymetry: International Bathymetric Chart Of The Arctic Ocean, Martin Jakobsson Jan 2001

Geographic Information Systems Tools For Collecting And Accessing Arctic Bathymetry: International Bathymetric Chart Of The Arctic Ocean, Martin Jakobsson

Center for Coastal and Ocean Mapping

No abstract provided.

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Comptel Observations Of The Blazars 3c 454.3 And Cta 102, S Zhang, W Collmar, V Schonfelder, H Bloemen, W Hermsen, Mark L. Mcconnell, K Bennett, O R. Williams Jan 2001

Comptel Observations Of The Blazars 3c 454.3 And Cta 102, S Zhang, W Collmar, V Schonfelder, H Bloemen, W Hermsen, Mark L. Mcconnell, K Bennett, O R. Williams

Space Science Center

We have analyzed the two blazars of 3C 454.3 and CTA 102 using all available COMPTEL data from 1991 to 1999. In the 10–30 MeV band, emission from the general direction of the sources is found at the 4σ-level, being consistent with contributions from both sources. Below 10 MeV only 3C 454.3 is significantly detected, with the strongest evidence (5.6 σ) in the 3–10 MeV band. Significant flux variability is not observed for both sources, while a low emission is seen most of the years in the 3–10 MeV light curve for 3C 454.3. Its time-averaged MeV spectrum suggests a …

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Comptel Gamma-Ray Observations Of The C4 Solar Flare On 20 January 2000, C A. Young, M B. Arndt, K Bennett, A Connors, H Debrunner, R Diehl, Mark L. Mcconnell, R S. Miller, G Rank, James M. Ryan, V Schonfelder, C Winkler Jan 2001

Comptel Gamma-Ray Observations Of The C4 Solar Flare On 20 January 2000, C A. Young, M B. Arndt, K Bennett, A Connors, H Debrunner, R Diehl, Mark L. Mcconnell, R S. Miller, G Rank, James M. Ryan, V Schonfelder, C Winkler

Space Science Center

The “Pre-SMM” (Vestrand and Miller 1998) picture of gamma-ray line (GRL) flares was that they are relatively rare events. This picture was quickly put in question with the launch of the Solar Maximum Mission (SMM). Over 100 GRL flares were seen with sizes ranging from very large GOES class events (X12) down to moderately small events (M2). It was argued by some (Bai 1986) that this was still consistent with the idea that GRL events are rare. Others, however, argued the opposite (Vestrand 1988; Cliver, Crosby and Dennis 1994), stating that the lower end of this distribution was just a …

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The Milagro Gamma-Ray Observatory, J E. Mcenery, R Atkins, W Benbow, D Berley, M L. Chen, D G. Coyne, B L. Dingus, D E. Dorfan, R W. Ellsworth, D Evans, A Falcone, L Fleysher, R Fleysher, G Gisler, J A. Goodman, T J. Haines, C M. Hoffman, S Hugenberger, L A. Kelley, I Leonor, Mark L. Mcconnell, J F. Mccullough, R S. Miller, A I. Mincer, M F. Morales, P Nemethy, James M. Ryan, B Shen, A Shoup, C Sinnis, A J. Smith, G W. Sullivan, O T. Tumer, K Wang, M O. Wascko, S Westerhoff, D A. Williams, G B. Yodh Jan 2001

The Milagro Gamma-Ray Observatory, J E. Mcenery, R Atkins, W Benbow, D Berley, M L. Chen, D G. Coyne, B L. Dingus, D E. Dorfan, R W. Ellsworth, D Evans, A Falcone, L Fleysher, R Fleysher, G Gisler, J A. Goodman, T J. Haines, C M. Hoffman, S Hugenberger, L A. Kelley, I Leonor, Mark L. Mcconnell, J F. Mccullough, R S. Miller, A I. Mincer, M F. Morales, P Nemethy, James M. Ryan, B Shen, A Shoup, C Sinnis, A J. Smith, G W. Sullivan, O T. Tumer, K Wang, M O. Wascko, S Westerhoff, D A. Williams, G B. Yodh

Space Science Center

The Milagro water Cherenkov detector began full operation in January 2000. This detector is capable of monitoring the Northern sky at energies above 500 GeV for sources of equivalent strength to the Crab Nebula over one year of integration. We report on the current performance and sensitivity of Milagro.

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