| On Near-Field w-Projection for Radio Interferometric Imaging |
12-May-2009 |
14 pages |
| Authors:
Joseph Lazio; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
 | This paper serves to elucidate the mathematical steps needed to apply near-field imaging over a significant (angular) area of regard, with specific application to the receiving sites of the Air Force Space Surveillance System (AFSSS, Space Fence). Cornwell has developed the mathematical formalism to merge near-field imaging with imaging over a wide field of view. The traditional far-field, narrow field-of-view imaging developed in radio astronomy can be extended to wide ... |
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| Navy Prototype Optical Interferometer Imaging of Line Emission Regions of Beta Lyrae Using Differential Phase Referencing |
01-Feb-2009 |
14 pages |
| Authors:
J T Armstrong; A M Jorgensen; K J Johnston; D J Hutter; R B Hindsley; J A Benson; C Tycner; T A Pauls; H R Schmitt; R T Zavala; G C Gilbreath; D Mozurkewich; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We present the results of an experiment to image the interacting binary star Beta Lyrae with data from the Navy Prototype Optical Interferometer using a differential phase technique to correct for the effects of the instrument and atmosphere on the interferometer phases. We take advantage of the fact that the visual primary of Beta Lyrae and the visibility calibrator we used are both nearly unresolved and nearly centrally symmetric, and ... |
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| High-Excitation OH and H2O Lines in Markarian 231: The Molecular Signatures of Compact Far-Infrared Continuum Sources |
01 MAR 2008 |
14 pages |
| Authors:
Eduardo Gonzalez-Alfonso; Howard A. Smith; Matthew L. Ashby; Jacqueline Fischer; Luigi Spinoglio; Timothy W. Grundy; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The ISO LWS far-infrared spectrum of the ultraluminous galaxy Mrk 231 shows OH and H2O lines in absorption from energy levels up to 300 K above the ground state. Our analysis shows that OH and H2O are radiatively pumped by the far-infrared continuum emission of the galaxy. The absorptions in the high-excitation lines require high far-infrared radiation densities, allowing us to constrain the properties of the underlying continuum source. The ... |
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| Disentangling the Dynamical Mechanisms for Cluster Galaxy Evolution |
FEB 2008 |
15 pages |
| Authors:
Xiaolei Zhang; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The determination of the dynamical causes of the morphological Butcher-Oemler (BO) effect, or the rapid transformation of a large population of late-type galaxies to earlier Hubble types in the rich cluster environment between intermediate redshifts and the local universe, has been an important unsolved problem that is central to our understanding of the general problems of galaxy formation and evolution. In this article, we survey the existing proposed mechanisms for ... |
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| Study of the Implications of Whitecap Intermittency on the Uniform Sea-salt Aerosol Source Approximation and Deposition Velocity |
29 OCT 2007 |
91 pages |
| Authors:
William A. Hoppel; Peter F. Caffrey; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The source function and deposition velocity of sea-salt particles used in large-scale models assumes that the source and deposition is uniform over areas large compared to the horizontal grid spacing of the model, whereas sea-salt aerosol is overwhelmingly generated by white caps whose surface distribution is usually sparse and sporadic. The analysis presented here uses several puff plume models to study the validity of the underlying assumptions of the horizontally ... |
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| Hydrodynamic Agents in the Littoral Environment. Phase 1 Progress Report |
06 JUL 2007 |
84 pages |
| Authors:
Charles M. Bachmann; C. R. Nichols; Richard P. Mied; Chung H. Read; Ellen Bennert; Robert A. Fusina; Timothy F. Donato; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Hydrodynamic Agents in the Littoral Environment (HALE) is a National Geospatial-Intelligence Agency program aimed at producing tidal predictions from imagery-derived water levels. HALE has been divided into three phases which lead to a protocol. This report describes Phase I and introduces work for Phase II. Approximately 62 satellite images of the Han River Estuary, Republic of Korea, over the 20-year period from 1987 to 2006 were processed and analyzed. The ... |
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| A Spitzer IRS Low-Resolution Spectroscopic Search for Buried AGNs in Nearby Ultraluminous Infrared Galaxies: A Constraint on Geometry Between Energy Sources and Dust |
JUL 2007 |
30 pages |
| Authors:
Masatoshi Imanishi; C. C. Dudley; Roberto Maiolino; Philip R. Maloney; Takao Nakagawa; Guido Risaliti; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We present the results of Spitzer Infrared Spectrograph low-resolution infrared 5 35 micrometers spectroscopy of nearby ultraluminous infrared galaxies (ULIRGs) at z < 0:15. We focus on the search for the signatures of buried active galactic nuclei (AGNs) in the complete sample of ULIRGs classified optically as non-Seyferts (LINERs or H ii regions). In addition to polycyclic aromatic hydrocarbon (PAH) emission features at 6.2, 7.7, and 11.3 micrometers, the conventional ... |
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| The NRL Long-Wavelength Test Array |
22 JUN 2007 |
27 pages |
| Authors:
K. P. Stewart; B. C. Hicks; P. C. Crane; P. S. Ray; C. Gross; E. Polisensky; A. Cohen; N. E. Kassim; K. W. Weiler; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The NRL Long-Wavelength Test Array (NLTA) was constructed to develop and test active baluns and electrically short dipoles for possible use as the primary wideband receiving elements for an emerging suite of large HF/VHF arrays including the Low Frequency Array (LOFAR) and the Long-Wavelength Array (LWA). Several dipoles of various designs and dimensions have been built and tested. Their useful range is when the dipoles arms are between approximately 1/8 ... |
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| Radiometric Characterization of a New Photovoltaic Cell Unit for Powering Modulating Retroreflectors |
19 JUN 2007 |
18 pages |
| Authors:
Xiaolei Zhang; James Murphy; G. C. Gilbreath; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We describe the experimental procedures and results of a detailed radiometric characterization of a new photovoltaic (PV) wafer unit intended for powering the Multiple Quantum Well (MQW) Modulating Retroreflector (MRR) using natural sunlight and/or system laser light as energy input, to enable autonomous operation of free-space optical data link using the MQW-MRR. Our initial measurements show that the PV wafer unit has an average power conversion efficiency of 7% to ... |
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| The Potential-Density Phase-Shift Method for Determining the Corotation Radii in Spiral and Barred Galaxies |
JUN 2007 |
25 pages |
| Authors:
Xiaolei Zhang; Ronald J. Buta; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We have developed a new method for determining the corotation radii of density waves in disk galaxies, which makes use of the calculated radial distribution of an azimuthal phase shift between the potential and density wave patterns. The approach originated from improved theoretical understanding of the relation between the morphology and kinematics of galaxies and of the dynamical interaction between density waves and the basic-state disk stars, which results in ... |
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| Gas at the Inner Disk Edge |
MAY 2007 |
13 pages |
| Authors:
John S. Carr; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| Infrared molecular spectroscopy is a key tool for the observation of gas in the innermost region of disks around T Tauri stars. In this contribution, we examine how infrared spectroscopy of CO can be used to study the inner truncation region of disks around T Tauri stars. The inferred inner gas radii for T Tauri star disks are compared to the inner dust radii of disks, to the expectations of ... |
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| Design Considerations for the Second-Generation NPOI Fringe Tracker and Science Beam Combiner |
18 DEC 2006 |
30 pages |
| Authors:
Xiaolei Zhang; Tom Armstrong; Sergio Restaino; Dave Mozurkewich; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We describe the motivations for and the conceptual design of the second-generation back-end beam combiner and fringe tracker for the Navy Prototype Optical Interferometer. The new back end is expected to result in much-improved data quality and sensitivity compared to the existing back end. It will also enable the observation of geostationary satellites in the visible and near infrared regions of the spectrum. |
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| Characterization of the Optical Throughput Performance of Navy Prototype Optical Interferometer (NPOI) |
MAY 2006 |
13 pages |
| Authors:
Xiaolei Zhang; J. T. Armstrong; III Clark James A.; G. C. Gilbreath; Robert Lucke; Sergio Restaino; David Mozurkewich; James A. Benson; Donald J. Hutter; Nat White; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We have developed an approach for systematically investigating the optical throughput performance of the different segments of a Michelson stellar interferometer, and applied it to the characterization of the Navy Prototype Optical Interferometer (NPOI). We report the results of the first phase of throughput measurements on NPOI, as well as some of the lessons learned. Since the current generation of ground-based optical interferometers all suffers from varying degree of throughput ... |
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| The Hyades Binary Theta2 Tauri: Confronting Evolutionary Models With Optical Interferometry |
MAY 2006 |
10 pages |
| Authors:
J. T. Armstrong; D. Mozurkewich; Arsen R. Hajian; K. J. Johnston; R. N. Thessin; Deane M. Peterson; C. A. Hummel; G. C. Gilbreath; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We determine the masses and magnitude difference of the components of the Hyades spectroscopic binary theta(2) Tauri. We find that both components appear to be less massive and/or brighter than predicted from some recent evolutionary models. The rapid rotation and unknown rotational inclination of both components introduce uncertainty in their luminosities and colors, but not enough to reconcile both of them with the evolutionary models. We measured the visual orbit ... |
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| A Nonlinear Optimization Algorithm for WindSat Wind Vector Retrievals |
MAR 2006 |
15 pages |
| Authors:
Michael H. Bettenhausen; Craig K. Smith; Richard M. Bevilacqua; Nai-Yu Wang; Peter W. Gaiser; Stephen Cox; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| WindSat is a space-based polarimetric microwave radiometer designed to demonstrate the capability to measure the ocean surface wind vector using a radiometer. We describe a nonlinear iterative algorithm for simultaneous retrieval of sea surface temperature, columnar water vapor, columnar cloud liquid water, and the ocean surface wind vector from WindSat measurements. The algorithm uses a physically based forward model function for the WindSat brightness temperatures. Empirical corrections to the physically ... |
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| NOGAPS-ALPHA Simulations of the 2002 Southern Hemisphere Stratospheric Major Warming |
2006 |
22 pages |
| Authors:
Douglas R. Allen; Lawrence Coy; Stephen D. Eckermann; John P. McCormack; Gloria L. Manney; Timothy F. Hogan; Young-Joon Kim; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| A high-altitude version of the Navy Operational Global Atmospheric Prediction System (NOGAPS) spectral forecast model is used to simulate the unusual September 2002 Southern Hemisphere stratospheric major warming. Designated as NOGAPS-Advanced Level Physics and High Altitude (NOGAPS-ALPHA), this model extends from the surface to 0.005 hPa (~85 km altitude) and includes modifications to multiple components of the operational NOGAPS system, including a new radiative heating scheme, middle-atmosphere gravity wave drag ... |
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| Experimental Results of a MEMS-Based Adaptive Optics System |
DEC 2005 |
5 pages |
| Authors:
Sergio R. Restaino; G. C. Gilbreath; Don M. Payne; Jonathan R. Andrews; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Adaptive optics techniques have been demonstrated in both laboratory and field tests, with a great level of scientific satisfaction, especially in astronomical and surveillance communities. Such successes have sparked the interest for these techniques in other fields, like biomedical imaging and industrial applications. However, to decrease complexity and costs, both very important issues for applications other than astronomical and surveillance, new technologies have to be brought to fruition. MEMS are ... |
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| NOGAPS-ALPHA Simulations of the 2002 Antarctic Stratospheric Major Warming |
DEC 2005 |
5 pages |
| Authors:
D. R. Allen; S. D. Eckermann; J. P. McCormack; L. Coy; G. L. Manney; T. F. Hogan; Y.-J. Kim; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| A new high-altitude (~0-85 km) version of the Navy Operational Global Atmospheric Prediction System (NOGAPS) global spectral forecast model has been developed as a joint effort of NRL's Space Science, Remote Sensing, and Marine Meteorology Divisions. This NOGAPS-Advanced Level Physics and High Altitude (NOGAPS-ALPHA) model is formulated with a higher top level than the operational NOGAPS model and with a new hybrid vertical coordinate that transitions from terrain-following in the ... |
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| Infrared 3-4 um Spectroscopic Investigation of a Large Sample of Nearby Ultraluminous Infrared Galaxies |
27 SEP 2005 |
25 pages |
| Authors:
Masatoshi Imanishi; C. C. Dodley; Philip R. Maloney; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present infrared L-band (3 4 m) nuclear spectra of a large sample of nearby ultraluminous infrared galaxies (ULIRGs). ULIRGs classified optically as non-Seyfert galaxies (LINERs, Hii regions, and unclassified) are our main targets. Using the 3.3 m polycyclic aromatic hydrocarbon (PAH) emission and absorption features at 3.1 m due to ice-covered dust and at 3.4 m produced by bare carbonaceous dust, we search for signatures of powerful AGNs deeply ... |
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| Polarimetric SAR Image Classification Employing Subaperture Polarimetric Analysis |
25 JUL 2005 |
4 pages |
| Authors:
T. L. Ainsworth; J. S. Lee; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Polarimetric SAR image classification remains an important research area. Various methods continue to be developed for specific applications. High-resolution polarimetric SAR systems and advances in computational and data storage capabilities have revived interest in novel polarimetric analysis techniques. Accordingly, subaperture analysis of polarimetric SAR data has received renewed attention. A central assumption of SAR image formation is that individual radar scatterers are stationary; they have no structure and provide a ... |
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| Comparison of Polarimetric SAR Techniques for the Measurement of Directional Ocean Wave Spectra |
25 JUL 2005 |
5 pages |
| Authors:
D. L. Schuler; J. S. Lee; E. Pottier; G. De Grandi; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Several methods have been investigated which use fully polarimetric synthetic aperture radar (POLSAR) data to measure directional ocean wave slope spectra. Independent techniques have been developed to measure wave slopes in the orthogonal SAR (azimuth/range) directions. In this paper, wave spectra measured using two polarimetric methods are investigated. Spectra developed using a) intensity-based polarimetric SAR methods and b) a more recent orientation/alpha angle algorithm are compared. NASA/JPL/AIRSAR L-band data from ... |
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| Improved Manifold Coordinate Representations of Hyperspectral Imagery |
25 JUL 2005 |
5 pages |
| Authors:
Charles M. Bachmann; Thomas L. Ainsworth; Robert A. Fusina; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| There are many well-known sources of nonlinearity present in hyperspectral imagery; these include bi-directional reflectance distribution function (BRDF) effects, multi-path scatter between heterogeneous pixel constituents, and the variable presence of water, an attenuating medium, in the scene. In recent publications, we have presented a data-driven approach to representing the nonlinear structure of hyperspectral imagery. The approach relies on graph methods to derive geodesic distances on the high-dimensional hyperspectral data manifold. ... |
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| A Comparison of Change Detection Statistics in POLSAR Images |
25 JUL 2005 |
5 pages |
| Authors:
P. R. Kersten; J. S. Lee; T. L. Ainsworth; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Change detection in polarimetric SAR (POLSAR) images is an important topic. Three statistics are compared on both simulated and real data for their efficacy in change detection. The three statistics are the contrast ratio, the ellipticity and the Bartlett test. The relative performance for these three test statistics on the two simulations is dramatically different. The results are illustrated and explained. |
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| FM-MRR Analog Audio System |
2005 |
9 pages |
| Authors:
J. L. Murphy; G. C. Gilbreath; W. S. Rabinovich; M. M. Sepantaie; P. G. Goetz; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| In this work, we describe a hybrid free-space infrared communications link that supports audio transmission. The technique combines conventional frequency modulation "FM" techniques with optical amplitude modulation "AM" with a Multiple Quantum Well "MQW" Modulating Retroreflector "MRR" technology. The method has produced a robust, low power system capable of transmitting high quality audio information over a free space infrared link extending to multiple kilometers, depending on the characteristics of the ... |
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| High-Resolution, Wide-Field Imaging of the Galactic Center Region at 330 MHz |
OCT 2004 |
26 pages |
| Authors:
Michael E. Nord; T. J. Lazio; Namir E. Kassim; S. D. Hyman; T. N. LaRosa; C. L. Brogan; N. Duric; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present a wide-field, subarcminute-resolution VLA image of the Galactic center region at 330 MHz. With a resolution of -7" x 12" and an rms noise of 1.6 mJy beam (exp -1), this image represents a significant increase in resolution and sensitivity over the previously published VLA image at this frequency. The improved sensitivity has more than tripled the census of small-diameter sources in the region, has resulted in the ... |
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| Cryogenic Far-Infrared Laser Absorptivity Measurements of the Herschel Space Observatory Telescope Mirror Coatings |
01 JUL 2004 |
8 pages |
| Authors:
Jacqueline Fischer; Tjeerd Klaassen; Niels Hovenier; Gerd Jakob; Albrecht Poglitsch; Oren Sternberg; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Far-infrared laser calorimetry was used to measure the absorptivity, and thus the emissivity, of aluminum-coated silicon carbide mirror samples produced during the coating qualification run of the Herschel Space Observatory telescope to be launched by the European Space Agency in 2007. The samples were measured at 77 K to simulate the operating temperature of the telescope in its planned orbit about the second Lagrangian point, L2, of the Earth Sun ... |
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| Mid- and Far-Infrared Infrared Space Observatory Limits on Dust Disks Around Millisecond Pulsars |
12 MAY 2004 |
5 pages |
| Authors:
T. J. Lazio; J. Fischer; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We report 60 and 90 micron observations of seven millisecond pulsars with the Infrared Space Observatory. The pulsar PSR B1257+12 is orbited by three planets, and other millisecond pulsars may be orbited by dust disks that represent planets that failed to form or their residue. We do not detect any infrared emission from the seven pulsars in our sample, and typical upper limits are 100 mJy. Using a simple model, ... |
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| A Deep, High-Resolution Survey at 74 MHz |
FEB 2004 |
15 pages |
| Authors:
A. S. Cohen; H. J. Roettgering; M. J. Jarvis; N. E. Kassim; T. J. Lazio; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present a 74 MHz survey of a 165 deg^2 region located near the north Galactic pole. This survey has an unprecedented combination of both resolution and sensitivity. We detect 949 sources in this region, enough to begin exploring the nature of the 74 MHz source population. We present differential source counts, spectral index measurements, and the size distribution as determined from counterparts in the high-resolution FIRST 1.4 GHz survey. ... |
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| Use of Two Deformable Mirrors AO System for an Interferometric Test-Bed |
01-Jan-2004 |
10 pages |
| Authors:
Ty Martinez; G C Gilbreath; Sergio R Restaino; Dave V Wick; Don T Payne; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| In this paper, we present results on a test-bed for the use of adaptive optics (AO) in optical interferometry. The test-bed is based on two deformable mirrors made by OKO technologies. The two mirrors are simultaneously controlled by the same computer and control software. The experimental set is based on our portable adaptive optics system. The goal of this test-bed is to study and characterize the effects of aberrations on ... |
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| Hydra A at Low Radio Frequencies |
JAN 2004 |
6 pages |
| Authors:
W. M. Lane; T. E. Clarke; G. B. Taylor; R. A. Perley; N. E. Kassim; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present new, low-frequency images of the powerful FR I radio galaxy Hydra A (3C 218). Images were made with the Very Large Array at frequencies of 1415, 330, and 74 MHz, with resolutions on the order of 20". The morphology of the source is seen to be more complex and even larger than previously known and extends nearly 8' (530 kpc) in a north-south direction. The southern lobe is ... |
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| Research in Free Space Optical Data Transfer at the U.S. Naval Research Laboratory |
2004 |
10 pages |
| Authors:
G. C. Gilbreath; William S. Rabinovich; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| In this paper, a review of the progress and initiatives in free space optical data transfer and communications at the Naval Research Laboratory is presented. NRL has been investing in research and development in optical communications and laser ranging, both conventional, and advanced. Efforts include developing amplifiers and components for lasers to be used in long range, one-way and retro-reflected links. NRL has been developing Multiple Quantum Well retromodulators for ... |
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| Developing a Portable NRL Fast Frame Rate Seeing Monitor |
2004 |
11 pages |
| Authors:
Bun Oh; James L. Murphy; Jeffrey T. Baker; G. C. Gilbreath; Robert B. Hindsley; David Mozurkewich; Sergio R. Restaino; Susan L. Fortenberry; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We describe the development of a portable NRL seeing monitor which consists of a 12 inch Meade f/10 telescope with a Dalsa Cad6 260x260 camera having 10 micron pixels. This seeing monitor is capable of up to 700 frames per second. We have three different techniques to measure Fried's r0 parameter: full aperture, two-hole mask, and two-hole mask with in-line intensifier. For the observations done at the Anderson Mesa, Arizona ... |
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| Alignment of Vacuum Feed Stations on the Navy Prototype Optical Interferometer |
2004 |
7 pages |
| Authors:
James A. Clark III; James Murphy; Long Ha; Joshua P. Walton; James Howard; J. T. Armstrong; G. C. Gilbreath; Robert B. Hindsley; Thomas A. Pauls; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| At the Navy Prototype Optical Interferometer (NPOI) we have developed a two-stage method for preparation and installation of the optical feed relay stations (elevators). This method reduces contamination, increases consistency, and allows greater management in testing and upgrades. In stage one, we prepare a pre-alignment facility in a laboratory. Using this facility we accurately position the feed stations, internal optics and detector optics relative to the NPOI array line-of-sight. The ... |
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| NPOI: Recent Technology and Science |
2004 |
9 pages |
| Authors:
J. A. Benson; D. J. Hutter; K. J. Johnston; R. T. Zavala; N. M. White; T. A. Pauls; G. C. Gilbreath; J. T. Armstrong; R. B. Hindsley; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We describe recent science projects that the Navy Prototype Optical Interferometer (NPOI) scientific staff and collaborators are pursuing. Recent results from the wide angle astrometric program and imaging programs (rapid rotators, binaries and Be stars) will be summarized. We discuss some of the technology that enables the NPOI to operate routinely as an observatory astronomical instrument. |
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| The [C II] 158 Micron Line Deficit in Ultraluminous Infrared Galaxies Revisited |
10 SEP 2003 |
19 pages |
| Authors:
M. L. Luhman; S. Satyapal; J. Fischer; M. G. Wolfire; E. Sturm; C. C. Dudley; D. Lutz; R. Genzel; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present a study of the [C II] 157.74-micrometer fine-structure line in a sample of 15 ultraluminous infrared (IR) galaxies using the Long Wavelength Spectrometer (LWS) on the Infrared Space Observatory (ISO). We confirm the observed order of magnitude deficit (compared to normal and starburst galaxies) in the strength of the [C II] line relative to the far-infrared (FIR) dust continuum emission found in our initial report, but here with ... |
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| The Low-Frequency Radio Counterpart of the XMM Large-Scale Structure Survey |
10 JUL 2003 |
23 pages |
| Authors:
A. S. Cohen; H. J. Roettgering; N. E. Kassim; W. D. Cotton; R. A. Perley; R. Wilman; P. Best; M. Pierre; M. Birkinshaw; M. Bremer; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The XMM Large-Scale Structure Survey (XMM-LSS) is a major project to map the large-scale structure of the universe out to cosmological distances. An 8 deg. x 8 deg. region will be surveyed by XMM with planned optical follow-up to produce a three-dimensional map of many hundreds of clusters out to a redshift of z - 1. To explore the relation of the large-scale structure to the location and properties of ... |
|
| Two Low Frequency Surveys of Radio Galaxies |
17 JAN 2003 |
7 pages |
| Authors:
A. S. Cohen; W. M. Lane; T. J. Lazio; N. E. Kassim; R. A. Perley; W. D. Cotton; J. Condon; H. J. Roettgering; R. Wilman; P. Best; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| High resolution, low frequency observations are very efficient for surveying radio galaxies because of: 1) the wide field of view and 2) the bias toward steep spectrum (lobe dominated) emission. Here I present preliminary results from two ongoing low frequency radio surveys: the 4 Meter All Sky Survey (4MASS) and the low frequency counterpart to the XMM-Large Scale Structure (XMM-LSS) survey. 4MASS is an NRL-NRAO project to survey the entire ... |
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| ASTROCAM: An Offner Re-imaging 1024 x 1024 InSb Camera for Near-Infrared Astrometry on the USNO 1.55-m Telescope |
2003 |
15 pages |
| Authors:
Jacqueline Fischer; Frederick Vrba; Douglas Toomey; Robert Lucke; Shu-i Wang; Arne Henden; Joseph Robichaud; Peter Onaka; Brian Hicks; Fred Harris; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| In order to extend the US Naval Observatory (USNO) small-angle astrometric capabilities to near infrared wavelengths we have designed and manufactured a 1024 x 1024 InSb re-imaging infrared camera equipped with an array selected from the InSb ALADDIN (Advanced Large Area Detector Development in InSb) development program and broadband and narrowband 0.8 - 3.8 um filters. Since the USNO 1.55-m telescope is optimized for observations at visible wavelengths with an ... |
|
| Secular Evolution of Spiral Galaxies |
2003 |
18 pages |
| Authors:
Xiaolei Zhang; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| It is now a well established fact that galaxies undergo significant morphological transformation during their lifetimes, manifesting as an evolution along the Hubble sequence from the late to the early Hubble types. The physical processes commonly believed to be responsible for this observed evolution trend, i.e. the major and minor mergers, as well as gas accretion under a barred potential, though demonstrated applicability to selected types of galaxies, on the ... |
|
| Analysis of the Naval Observatory Flagstaff Station 1-m Telescope using Annular Zernike Polynomials |
2003 |
6 pages |
| Authors:
Sergio R. Restaino; Scott W. Teare; Michael Divittorio; G. C. Gilbreath; David Mozurkewich; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The Naval Observatory Flagstaff Station 1-m telescope is evaluated for the addition of adaptive optics capabilities to its instrumentation suite. Zernike decomposition of the optical system based on phase diversity measurements shows that the static optical aberrations are small enough that they will not degrade the performance of the deformable optical element. The analysis makes use of annular pupil Zernike polynomial reconstruction of the wavefront to accommodate the large obscuration ... |
|
| Liquid Crystal Technology for Adaptive Optics: an Update |
2003 |
7 pages |
| Authors:
Sergio R. Restaino; Don M. Payne; Jeff T. Baker; Jonathan R. Andrews; Scott W. Teare; G. C. Gilbreath; Dave Dayton; John Gonglewski; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The idea of using liquid crystal (LC) devices as an adaptive optics component has been proposed by several authors. In recent years a vigorous research effort has been carried out, and it is still flourishing, in several countries. Mainly the research and experimental work has been concentrated in the USA, U.K. and Russia. There are several reasons why liquid crystals may represent a valid alternative to the traditional deformable mirror ... |
|
| Automatic Classification of Land Cover on Smith Island, VA, Using HyMAP Imagery |
OCT 2002 |
19 pages |
| Authors:
Charles M. Bachmann; Timothy F. Donato; Gia M. Lamela; W. J. Rhea; Michael H. Bettenhauen; Robert A. Fusina; Kevin R. Du Bois; John H. Porter; Barry R. Truitt; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
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| 3C 129 at 90 Centimeters: Evidence for a Radio Relic? |
JUN 2002 |
6 pages |
| Authors:
W. M. Lane; N. E. Kassim; T. A. Ensslin; D. E. Harris; R. A. Perley; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We present a new wide-field map of the radio galaxy 3C 129 and its companion galaxy 3C 129.1. We see a distinct steep-spectrum feature near the head of 3C 129, extending in a direction perpendicular to the radio tails. We propose that this Crosspiece might consist of fossil radio plasma, which has been reenergized by the compression of the bow shock of the supersonically moving galaxy 3C 129. One possible ... |
|
| Ocean PHILLS Hyperspectral Imager: Design, Characterization, and Calibration |
25 FEB 2002 |
13 pages |
| Authors:
Curtiss O. Davis; Jeffrey Bowles; Robert A. Leathers; Dan Korwan; T. V. Downes; William A. Snyder; W. J. Rhea; Wei Chen; John Fisher; W. P. Bissett; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| The Ocean Portable Hyperspectral Imager for Low-Light Spectroscopy (Ocean PHILLS) is a hyperspectral imager specifically designed for imaging the coastal ocean. It uses a thinned, backside illuminated CCD for high sensitivity and an all-reflective spectrograph with a convex grating in an Offner configuration to produce a nearly distortion free image. The sensor, which was constructed entirely from commercially available components, has been successfully deployed during several oceanographic experiments in 1999-2001. ... |
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| Modulating Retro-Reflectors for Space, Tracking, Acquisition and Ranging using Multiple Quantum Well Technology (Preprint) |
2002 |
15 pages |
| Authors:
G. C. Gilbreath; N. G. Creamer; W. S. Rabinovich; Timothy J. Meehan; Michael J. Vilcheck; John A. Vasquez; Rita Mahon; Eun Oh; Peter G. Goetz; Sharon Mozersky; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| This paper describes a novel concept for optical interrogation, communication, and navigation between spacecraft platforms. The technique uses a gimbaled laser source on a pursuer spacecraft and an array of solid-state, multiple quantum well modulating retroreflectors on a target spacecraft. The sensor system provides high-bandwidth optical communication, centimeter-level relative positioning, and better than arc-minute-level relative attitude of the target platform with minimal sacrifice in target size, weight, and power. To ... |
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| Multifrequency Very Long Baseline Array Observations of the Compact Double B2 2050+36: Constraints on Interstellar Scattering Revisited |
20 OCT 2001 |
10 pages |
| Authors:
T. J. Lazio; A. L. Fey; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We present multifrequency observations with the Very Long Baseline Array of the compact double radio source B2 2050+36. Our observations are at 0.33, 0.61, 1.67, 2.3, and 8.4 GHz, with the 0.61 GHz observations forming the third epoch of observation of this source at that frequency. At 0.61 GHz, the structure of B2 2050+36 is dominated by two components 56 mas apart. Within the uncertainties of the various measurements, this ... |
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| Spatially Resolved Thermal Continuum Absorption Against Supernova Remnant W49B |
01 OCT 2001 |
10 pages |
| Authors:
C. K. Lacey; T. J. Lazio; Namir E. Kassim; N. Duric; D. S. Briggs; K. K. Dyer; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We present subarcminute resolution imaging of the Galactic supernova remnant W49B at 74 MHz (25") and 327 MHz (6"), the former being the lowest frequency at which the source has been resolved. While the 327 MHz image shows a shell-like morphology similar to that seen at higher frequencies, the 74 MHz image is considerably different, with the southwest region of the remnant almost completely attenuated. The implied 74 MHz optical ... |
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| Evidence for Residual Material in Accretion Disk Gaps: CO Fundamental Emission from the T Tauri Spectroscopic Binary DQ Tauri |
10 APR 2001 |
8 pages |
| Authors:
John S. Carr; Robert D. Mathieu; Joan R. Najita; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| We present the discovery of CO fundamental rovibrational emission from the classical T Tauri spectroscopic binary DQ Tau. The high-resolution infrared echelle spectra reveal emission lines from both the gamma = 1 and gamma = 2 vibrational levels with line widths of roughly 70 km s(exp -1). The average CO excitation temperature is approximately 1200 K. We model the spectra as arising from gas in Keplerian rotation about the center ... |
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| Photoionization Modeling of Infrared Fine-Structure Lines in Luminous Galaxies with Central Dust-Bounded Nebulae |
2001 |
5 pages |
| Authors:
Jacqueline Fischer; Robert Allen; C. C. Dudley; Shobita Satyapal; Michael L. Luhman; Mark G. Wolfire; Howard A. Smith; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| Far-infrared spectroscopy of a small sample of IR-bright galaxies taken with the Infrared Space Observatory Long Wavelength Spectrometer has revealed a dramatic progression extending from strong fine-structure line emission from photoionized and photodissociated gas in the starburst galaxy Arp 299 to faint [C II]158 micrometers line emission and absorption in lines of OH, H2O, CH, and [O I] in the ultraluminous galaxy Arp 220. The progression to weaker emission lines ... |
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| The First Stellar Abundance Measurements in the Galactic Center: The M Supergiant IRS 7 |
10 FEB 2000 |
17 pages |
| Authors:
John S. Carr; K. Sellgren; Suchitra C. Balachandran; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| The first measurement of the photospheric abundances in a star at the Galactic center are presented. A detailed abundance analysis of the Galactic center M2 supergiant IRS 7 was carried out using high-resolution near-infrared echelle spectra. The Fe abundance for IRS 7 was found to be close to solar, [Fe/H] = 0.02 +/- 0.13, and nearly identical to the Fe abundance we obtained for the nearby M supergiants alpha Ori ... |
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