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in subjects: "Night Sky"

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The Sloan Digital Sky Survey: Status and prospects

The Sloan Digital Sky Survey (SDSS) is a project to definitively map {pi} steradians of the local Universe. An array of CCD detectors used in drift-scan mode will digitally image the sky in five passbands to a limiting magnitude of r{prime} {approximately} 23. Selected from the imaging survey, 10{sup 6} galaxies and 10{sup 5} quasars will be observed spectroscopically. I describe the current status of the survey, which is due to begin observations early in 1997, and its prospects for constraini… more

Date: May 1, 1996

Creator: Loveday, J. & Collaboration, SDSS

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Variable White Dwarf Data Tables

Below, I give a brief explanation of the information in these tables. In all cases, I list the WD {number_sign}, either from the catalog of McCook {ampersand} Sion (1987) or determined by me from the epoch 1950 coordinates. Next, I list the most commonly used name (or alias), then I list the variable star designation if it is available. If not, I list the constellation name and a V** or?? depending on what the last designated variable star for that constellation is. I present epoch 2000 coordin… more

Date: December 31, 1997

Creator: Bradley, P. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A study of turbulence in an evolving stable atmospheric boundary layer using large-eddy simulation

A study is made of the effects of stable stratification on the fine-scale features of the flow in an evolving stable boundary layer (SBL). Large-eddy simulation (LES) techniques are used so that spatially and temporally varying and intermittent features of the turbulence can be resolved; traditional Reynolds-averaging approaches are not well suited to this. The LES model employs a subgrid turbulence model that allows upscale energy transfer (backscatter) and incorporates the effects of buoyancy… more

Date: May 1, 1999

Creator: Cederwall, R & Street, R L

Item Type: Article

Partner: UNT Libraries Government Documents Department

[Photograph of cirrocumulus clouds surrounding the moon]

Photograph of the night sky. The moon is bright and surrounded by spotty, cirrocumulus clouds. No stars can be seen.

Date: [1939..1989]

Creator: Clark, Joe

Item Type: Photograph

Partner: UNT Libraries Special Collections

open access

THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL

A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric Modeling System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against t… more

Date: April 2, 2009

Creator: Werth, D.; Kurzeja, R. & Parker, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

MULTISCALE THERMAL-INFRARED MEASUREMENTS OF THE MAUNA LOA CALDERA, HAWAII

Until recently, most thermal infrared measurements of natural scenes have been made at disparate scales, typically 10{sup {minus}3}-10{sup {minus}2} m (spectra) and 10{sup 2}-10{sup 3} m (satellite images), with occasional airborne images (10{sup 1} m) filling the gap. Temperature and emissivity fields are spatially heterogeneous over a similar range of scales, depending on scene composition. A common problem for the land surface, therefore, has been relating field spectral and temperature meas… more

Date: March 1, 2001

Creator: BALICK, L.; GILLESPIE, A. & AL, ET

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Progress report of FY 1998 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

Previously, the proposers have delivered to ARM a documented algorithm, that is now applied operationally, and which derives water vapor profiles from combined remote sensor measurements of water vapor radiometers, cloud-base ceilometers, and radio acoustic sounding systems (RASS). With the expanded deployment of a Raman lidar at the CART Central Facility, high quality, high vertical-resolution, water vapor profiles will be provided during nighttime clear conditions, and during clear daytime co… more

Date: October 1, 1999

Creator: Westwater, Edgeworth R. & Han, Yong

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Science & Technology Review November 2005

This month's issue has the following articles: (1) A Major Advance in Understanding Metals--Commentary by Tomas Diaz de la Rubia; (2) Materials Scientists Discover the Power of ParaDiS--A new supercomputer code is revealing how metals become stronger through the formation of dislocation line junctions; (3) A Wide New Window on the Universe--Livermore scientists and engineers are contributing to the Large Synoptic Survey Telescope, which will provide unprecedented digital maps of the changing ni… more

Date: September 19, 2005

Creator: Aufderheide, M B

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Progress report of FY 1999 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

Date: September 10, 1999

Creator: Westwater, Edgeworth R. & Han, Yong

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Elevated stratified layers observed during VTMX.

A suite of instrumentation including a minisodar, a low-frequency, single-axis sodar, a wind profiling radar and a tethersonde was used during the Vertical Transport and Mixing field study in Salt Lake City, UT, USA, to study the evolution and dynamics of stratified layers that commonly develop during nighttime. The month-long field study provided ten nights with good conditions for tethersonde flights. The real-time sodar display was used to place the tethersonde within and near the stratified… more

Date: March 14, 2002

Creator: Coulter, R. L.; Pekour, M. S. & Martin, T. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Progress report of FY 1997 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

Date: October 5, 1997

Creator: Westwater, Edgeworth R. & Han, Yong

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

RAMAN LIDAR PROFILING OF WATER VAPOR AND AEROSOLS OVER THE ARM SGP SITE.

We have developed and implemented automated algorithms to retrieve profiles of water vapor mixing ratio, aerosol backscattering, and aerosol extinction from Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Raman Lidar data acquired during both daytime and nighttime operations. This Raman lidar system is unique in that it is turnkey, automated system designed for unattended, around-the-clock profiling of water vapor and aerosols (Goldsmith et al., 1998). These Raman lidar profiles … more

Date: January 9, 2000

Creator: FERRARE,R.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Night vision device technology development

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop microchannel plate (MCP) technologies for enhancement of night vision device (NVD) capabilities. First, the authors addressed the need for segmented microchannel plates with independent gain control to minimize loss of low level light images in the presence of a bright light source (e.g., battlefield lasers, flares, and … more

Date: December 31, 1998

Creator: Funsten, H.; Nordholt, J. & Suszcynsky, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Improved instrumentation for near-real-time measurement of reactive hydrocarbons, NO{sub 2}, and peroxyacyl nitrates.

The measurement of reactive hydrocarbons and associated nitrogen oxides, NO{sub 2}, and peroxyacyl nitrates (PANs) is of key importance to unraveling the complex chemistries involved in daytime photochemical oxidant formation and nighttime chemistry driven by the nitrate radical. Recent work has demonstrated that chemiluminescent reactions of ozone with hydrocarbons (and the temperature dependence of the reactions) can be used as a means of detecting a wide variety of organic compounds in the g… more

Date: October 6, 1999

Creator: Drayton, P. J.; Blazer, C. A.; Gaffney, J. S. & Marley, N. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Puerto Rico - 2002 : field studies to resolve aerosol processes.

A number of questions remain concerning homogeneous aerosol formation by natural organics interacting with anthropogenic pollutants. For example, chlorine has been proposed as a potential oxidant in the troposphere because of its very high reactivity with a wide range of organics (Finlayson-Pitts, 1993). Indeed, sea salt aerosol in the presence of ozone has been shown to produce chlorine atoms in heterogeneous photochemical reactions under laboratory conditions. Whether chlorine can initiate ox… more

Date: October 5, 1999

Creator: Gaffney, J. S.; Marley, N. A. & Ravelo, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of natural radionuclides for determination of tropospheric ozone and aerosol transport.

Natural radionuclides have been proposed for use in assessing the transport of ozone and aerosols in the troposphere. For example, {sup 7}Be is known to be produced in the upper troposphere and lower stratosphere by interactions with cosmogenic particles. Beryllium-7 has a 53.28-day half-life and is a gamma emitter that attaches itself to fine particles in the atmosphere once it is formed. Indeed, in tropospheric aerosol samples TBe is typically found in association with aerosol particles that … more

Date: December 6, 2000

Creator: Gaffney, J. S.; Marley, N. A.; Drayton, P. J. & Orlandini, K. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Quality studies of the data taking conditions for the Auger fluorescence detector

As more than half of the Fluorescence Detector (FD) of the Auger Observatory is completed, data taking is becoming a routine job. It is then necessary to follow strict procedures to assure the quality of the data. An overview of the data taking methods is given. The nature of the FD background signal is due to the night sky brightness (stars and planet faint light, moonlight, twilight, airglow, zodiacal and artificial light) and to the electronic background (photomultiplier and electronic noise… more

Date: July 1, 2005

Creator: Caruso, R.; Fonte, R.; Insolia, A.; Petrera, S.; Rodriquez Martino, J. & /Rome U.,Tor Vergata

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Building America Industrialized Housing Partnership (BAIHP)

This final report summarizes the work conducted by the Building America Industrialized Housing Partnership (www.baihp.org) for the period 9/1/99-6/30/06. BAIHP is led by the Florida Solar Energy Center of the University of Central Florida and focuses on factory built housing. In partnership with over 50 factory and site builders, work was performed in two main areas--research and technical assistance. In the research area--through site visits in over 75 problem homes, we discovered the prime ca… more

Date: June 30, 2006

Creator: McIlvaine, Janet; Chandra, Subrato; Barkaszi, Stephen; Beal, David; Chasar, David; Colon, Carlos et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The SDSS data archive server

The Sloan Digital Sky Survey (SDSS) Data Archive Server (DAS) provides public access to data files produced by the SDSS data reduction pipeline. This article discusses challenges in public distribution of data of this volume and complexity, and how the project addressed them. The Sloan Digital Sky Survey (SDSS)1 is an astronomical survey of covering roughly one quarter of the night sky. It contains images of this area, a catalog of almost 300 million objects detected in those images, and spectr… more

Date: October 1, 2007

Creator: Neilsen, Eric H., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tip-tilt compensation: Resolution limits for ground-based telescopes using laser guide star adaptive optics. Revision 2

The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a … more

Date: October 8, 1992

Creator: Olivier, S. S.; Max, C. E.; Gavel, D. T. & Brase, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Planets and Stars under the Magnifying Glass

Looking out to the vastness of the night sky, stargazers often ponder questions about the universe, many wondering if planets like ours can be found somewhere out there. But teasing out the details in astronomical data that point to a possible Earth-like planet is exceedingly difficult. To find an extrasolar planet--a planet that circles a star other than the Sun--astrophysicists have in the past searched for Doppler shifts, changes in the wavelength emitted by an object because of its motion. … more

Date: February 12, 2007

Creator: Hazi, A U

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Method of measuring nighttime U-values using the Mobile Window Thermal Test (MoWiTT) Facility

Although primarily designed for studying the dynamic net energy flows through fenestration systems over the full diurnal cycle, the Mobile Window Thermal Test (MoWiTT) Facility is also frequently used to measure nighttime U-values. These measurements have the advantage of incorporating the exterior film coefficient resulting from the true ambient conditions at a particular time and location, rather than relying on a laboratory simulation of some assumed average or extreme condition. On the othe… more

Date: April 1, 1992

Creator: Klems, J. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Phoenix, Arizona, revisited : indications of aerosol effects on O{sub 3}, NO{sub 2}, UV-B, and NO{sub 3}.

Fine particulate matter and tropospheric ozone levels are of concern because of their potential for health impacts, as well as their radiative effects. Both ozone and PM-2.5 standards are being exceeded in many urban and regional areas where transport and background levels can appreciably affect observed concentrations. Anthropogenic nitrogen oxides and other primary pollutant species can interact with natural organics to form secondary aerosol products via synthesis of nitric acid and its subs… more

Date: September 30, 1999

Creator: Gaffney, J. S.; Marley, N. A.; Drayton, P. J.; Cunningham, M. M.; Baird, J. C.; Dintaman, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Regional-scale influences on urban air quality : a field study in Phoenix, Arizona.

Regional air quality can play an important role in determining whether urban ozone or PM-2.5 standards are exceeded. Background levels of nitrogen oxide species (NO{sub x}) and their interactions with natural organics can generate secondary aerosol products via formation of nitric acid and its subsequent reaction with ammonia to form ammonium nitrate. Natural organics and reactive anthropogenic organic compounds, particularly aromatic species and monoterpenes, can also lead to the formation of … more

Date: October 12, 1998

Creator: Gaffney, J. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department