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LWA: The Long Wavelength Array

LWA Web sites:   http://lwa.nrl.navy.mil/, http://lwa.unm.edu, and links therein.

I. General project/facility description

  1. Overview of the facility/project
    The Long Wavelength Array (LWA) will be a major new instrument for low frequency (10-88 MHz) radio science, serving the radio astronomy, space physics, and ionospheric science communities. The instrument will be developed with the combined expertise and involvement of the participating universities, the Naval Research Laboratory (NRL) of the Department of Defense, the Los Alamos National Laboratory (LANL) of the Department of Energy (DoE), and the National Radio Astronomy Observatory (NRAO). A major focus will be to engage individual astronomers and the US university radio astronomy community in development and use of this instrument.

  2. Managing institution and organization
    The South West Consortium (SWC) consists of four institutions: the University of New Mexico (UNM); the University of Texas at Austin through its Applied Research Laboratories (ARL-UT); the Los Alamos National Laboratory (LANL) operated by the University of California for the DoE; and the Naval Research Laboratory (NRL) of the DoD (Basic research at the Naval Research Laboratory is supported by the Office of Naval Research.). In addition, the SWC has significant collaborations with non-member entities including the NRAO as well as individuals who are participating in the LWA development. UNM is providing fiscal and program oversight for the LWA through individual institutions that also participate independently in the R&D of this project.

  3. Funding source(s)
    Current activities are funded by individual members of the SWC including key personnel, workshops and related support. Phase I of the LWA is a demonstration array of two stations and is primarily funded through program funds of NRL. LANL supports LWA activities through internal funding, including the Laboratory Directed Research and Development program. Significant contributions for funding of future stages are expected from more than one federal agency, including DoE, DoD, and the National Science Foundation (NSF).

  4. Construction history and cost

    Time

    Phase

    Description

    Acronym

    Est Cost

    1991-1998

    0

    Existing 74 MHz VLA

    VLA74

    completed

    2004-2006

    I

    Long Wavelength Development Array

    (2 Stations + 74 MHz VLA)

    LWDA

    funded

    2006-2009

    II

    Long Wavelength Intermediate Array

    (7 new stations + infrastructure)

    LWIA

    $18.5M

    2008-2010

    III

    LWA Core

    LWAC

    ~$20M

    2010-2012

    IV

    High Resolution LWA

    LWA

    ~$20M

    2010-

    V

    LW Operations and Science Center

    LWOSC

    0.25M


  5. Operational history and cost

    Time

    Phase

    Description

    Acronym

    Est Cost

    1998

    0

    Existing 74 MHz VLA

    VLA74

    funded

    2005-2006

    I

    Long Wavelength Development Array

    (2 Stations + 74 MHz VLA)

    LWDA

    funded

    2006-2009

    II

    Long Wavelength Intermediate Array

    LWIA

    $1.5M

    2008-2010

    III

    LWA Core

    LWAC

    $1.0M

    2010-2012

    IV

    High Resolution LWA

    LWA

    $1.0M

    2010-

    V

    LW Operations and Science Center

    LWOSC

    0.5M/yr


II. Technical details

  1. Specifics of telescope/instrument
    Frequency Range10- 88 MHz
     (20 - 80 MHz optimized)
    Effective Collecting Area106 (15 MHz/ν2)m2
    Number of Dipole Elements ~ 13,000
    Number of Dipole Stations~52
    Baseline Range 0.2 - 400 km
    Point-Source Sensitivity 2.2 mJy @ 15 MHz
    (2 polarization, 1 hour, 4 MHz BW) 1.1 mJy @ 30 MHz
     0.7 mJy @ 75 MHz
    Angular Resolution 10″ @ 15 MHz
      5″ @ 30 MHz
      2″ @ 75 MHz
    Mapping Capability Full field of view
    Number of Independent FOV (beams)8
    Maximum Observable Bandwidth32 MHz
    Spectral Resolution ≤ 1 KHz
    Image Dynamic Range≥ 104
    Digitized BandwidthFull RF

    See also http://lwa.nrl.navy.mil/LWA/LWA.specs.html)

  2. New capabilities anticipated/planned in next 5-10 years

    The LWA is being developed as a staged project in 5 phases. Phase 0 is the currently operational NRL-NRAO developed 74 MHz system on the VLA. The project has been funded through Phase I, which is currently under construction.Please see http://lwa.nrl.navy.mil/LWA/steps/.

    Many of the greatest discoveries in astrophysics have coupled key technical innovations with the opening of new windows on the EM spectrum. The technical breakthrough in long wavelength astronomy has already occurred in the demonstration of ionospheric calibration with 74 MHz VLA. The LWA also introduces new observing paradigms such as multi-beaming and wide-field sky monitoring. The wavelength range below 100 MHz remains the last poorly explored spectral regime.

    When completed, the LWA will provide improvements of 2-3 orders of magnitude in imaging power (resolution and sensitivity) over past and present instruments.

    UNM is a member of a major initiative between US universities and private companies to provide a national scale network beyond Internet 2 called National LambdaRail ( http://www.nlr.net/index.html). The LambdaRail would be used by the LWA to serve LWA data to distributed computing facilities or to other research facilities.

III. User profile

  1. % of "open skies" time
    100%
  2. Institutional affiliations of users
    US universities, US national laboratories, and international users.

  3. Student access, involvement, usage
    Students will be an integral part of the LWA instrument planning and development process. Undergraduate and graduate students are currently being supported at NRL and ARL-UT for LWA science and technology development; LWA Phase 0 observations have and continue to support the PhD thesis work of many graduate students. Students will also be involved in science activities at all stages of the instrument as part of our commitments to revitalize radio astronomy at the university level, to develop the next generation of technically-aware and scientifically-astute radio astronomers, and to craft new, powerful techniques for the use of modern instrumentation.

IV. Science Overview

  1. Current forefront scientific programs
    On-going science programs with LWA Phase 0 - includes VLA 74 and 330 MHz.

    Technical studies
  2. Major discoveries (through 1999)
    With Phase I under construction, the LWA is currently operational under Phase 0, which is comprised of the 74 MHz system at the VLA. While this modest narrow-band system is very limited in resolution and sensitivity compared to the broad-band LWA, it nonetheless represents a major step forward over previous capabilities below 100 MHz. Results from Phase 0 are validating many aspects of the broad-based LWA science case, and have resulted in unique astronomical achievements, a few of which are listed below. (Includes results from both the 74 and 330 MHz VLA systems, the latter providing the platform on which software solutions to many generic data reduction challenges - e.g. RFI excision and wide-field imaging - have been pioneered.) An extensive bibliography of scientific results from both the 330 MHz and 74 MHz low frequency VLA systems can be found at: http://lwa.nrl.navy.mil/LWA/publications.html. The far more powerful LWA instrument will go much further to open this poorly explored spectral region, bringing the strong potential for unique discovery science.


  3. Science highlights of last 5 years

  4. Main future science questions to be addressed

    A text description of these goals can be found at http://lwa.nrl.navy.mil/LWA/LWA_science_summary.html

  5. Synergies with other major forefront facilities

  6. Unique contributions

V. Education/Outreach activities

  1. Visitor facility
    A key visitor and educational center associated with the LWA will be the existing LodeStar Astronomy Center (LAC), which is a UNM project located at, and operating in partnership with, the New Mexico Museum of Natural History (a State of New Mexico project) in Albuquerque. The LAC serves about 350,000 people per year, many from underserved populations in New Mexico and the Southwest, with informal educational programs at the facility, which includes a fully digital planetarium. It reaches an additional 25,000 people each year through its state-wide outreach program based on portable planetariums, star parties, teacher workshops, and hands-on activities. We propose to tie the Long Wavelength Array education and public outreach efforts into the LAC, which currently lacks a radio astronomy component. This would include new exhibit development at the LAC, and incorporation of radio astronomy content into the informal educational programs.

    Near the telescope core, the SWC will cooperate in the activities at the VLA visitor center near the VLA site in central NM. We also expect to engage in joint visitor and educational activities with FASR and any other projects doing science on the Plains of San Augustin.

  2. Student programs
    Two university led efforts will emerge which provide a strong educational focus to the LWA activities. First there will be the LWA Science Center affiliated with the Physics and Astronomy Department at the University of New Mexico which will attract scientists and students, and will house the imaging center and the computing facility associated with LWA. There will be an aggressive program of research activities for undergraduates (such as REU type programs), graduate student participation, postdoctoral funding and facilities and visiting scientist facilities. A second important center will be located at the University of Texas, Austin and will focus on ionospheric studies. As part of the Advanced Research Laboratories at UT (ARL-UT), the Ionospheric Center will host both undergraduate and graduate students as well as post-docs and other visitors interested in ionospheric studies. These two university based science centers will focus on directly engaging students interested in radio astronomy in LWA activities.

    The SWC team institutions will host a variety of scientific activities, which in addition to astronomy programs include: physics, computing, imaging, and engineering activities. LANL and NRL have a long tradition of supporting students and postdocs in their activities and will make LWA a key focus for this type of outreach activity. The founding universities involved in the LWA have degree programs in astrophysics, physics, mathematics and statistics, computer science, and electrical and computer engineering. In addition, the SWC is actively courting participation by other interested higher-education institutions with similar academic and research interests. Thus the training of many students across these various departments will help strengthen the US university base in radio astronomy and instrumentation.

    Of particular interest for the development of the next generation of engineers, physicists, astronomers, and computer scientists, is the ability of the southwestern universities to engage minority (largely Hispanic and Native American) students in exciting scientific projects and discoveries. UNM and UT-Austin are federally-recognized Minority Serving Institutions. NRL and LANL are committed to supporting diversity in their institutions and to serving the aspirations of their communities.

  3. Other
    In September 2004 an SWC-organized international conference with over 80 attendees was held in Santa Fe, New Mexico. The meeting honored Professor Emeritus William C. Erickson, a pioneer in low frequency radio astronomy. It brought together a diverse group of scientists whose interests included astrophysics, space physics, solar and planetary science, space weather, and ionospheric physics. The successful meeting helped validate the underlying low frequency science case and demonstrated community-wide support for development of the project. More information about the meeting, including PDF files of many of the presentations, can be found at the link below. The proceedings will be published by PASP and are currently under preparation (http://lwa.nrl.navy.mil/WCE/).

VI. Documentation/website URLs

  1. URL of facility website
  2. URL of EPO website
    Future facility; NYA.
  3. URL(s) of any brief overviews of project/facility
  4. URL(s) of miscellaneous documentation
  5. URL's of related web sites:

This page created and maintained for the RMSPG by Martha Haynes Last modified by W. Peters: Fri Feb 11 13:47:39 EST 2005