Searching for Data with the Virtual ITM Observatory

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Searching for Data with the Virtual ITM Observatory

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Title: Searching for Data with the Virtual ITM Observatory


1
Searching for Data with the Virtual ITM
Observatory
  • D. Morrison, M. Weiss, R. Daley, L. Immer, C.
    Colclough, R. Holder, J. Jen, D. Patrone, M.
    Hashemian, P. Meckel, M. Potter, R. Barnes, S.
    Nylund, J.-H. Yee, and E. Talaat
  • (Johns Hopkins University, Applied Physics
    Laboratory 11100 Johns Hopkins Rd. Laurel MD,
    20723 240-228-4172)
  • J. Russell
  • (Hampton University)
  • R. Heelis
  • (Univ. Texas at Dallas)
  • J. Kozyra
  • (Univ. of Michigan)
  • D. Bilitza, R. McGuire, and R. Candey
  • (NASA Goddard Spaceflight Center)
  • P. Fox
  • (HAO/NCAR)

2
Primary Tasks for Mission Data Center or Virtual
Observatory
  • (1) describe their data holdings and resources
  • (2) discover what data sets are available for
    solving the users particular science problem
  • (3) provide a means to access this data or
    resource
  • (4) provide tools to help personnel use the data
    that they have found.

3
What is a VxO?
  • A Virtual Observatory (VO) is a suite of
    software applications on a set of computers that
    allows users to uniformly find, access, and use
    resources (data, software, document, and image
    products and services using these) from a
    collection of distributed product repositories
    and service providers. A VO is a service that
    unites services and/or multiple repositories.
  • An observatory is a location used for observing
    terrestrial and/or celestial events.
  • A virtual observatory is a system that allows an
    observer to work as if they were at the
    observatory.
  • The VO does this typically by allowing the
    observer to access multiple data files
    (observations) from multiple sources of the
    object of interest.
  • The VO allows access to different instruments
    to study a given system or phenomena.
  • VitmO ties together multiple data sets from
    different satellites and ground stations to
    create the appearance of having many different
    types of instruments observing the same phenomena
    from different locations.

4
Virtual ITM Observatory
  • The Virtual ITM Observatory (VITMO) is one of the
    recently awarded domain specific NASA virtual
    observatories (VxO).
  • VITMO will focus on data covering the ITM region
    as well as providing connections to the energy
    drivers for this region (principally solar and
    magnetospheric).
  • VITMO is focused on the interdisciplinary ITM
    user rather than the instrument team user.

5
ITM is Diverse in Observables
An ITM VO must facilitate correlative study
between multiple parameters from multiple sources
and cross-discipline studies.
6
ITM Domain Differences
  • Data covering the ITM region has a number of
    differences from data in other domains.
  • The ITM region is observed by ground based remote
    sensing instruments, satellite based remote
    sensing instruments, and in-situ satellite
    instruments.
  • There are external drivers in solar radiation and
    the solar wind and magnetospheric particle
    inputs.
  • A Virtual Observatory that covers the ITM region
    needs to deal with the large diversity of data
    types in the study of this region.
  • A heterogeneous data format environment also
    exists here.
  • Solar imagery is typically in FITS files, ground
    based data are typically ASCII or NetCDF, in-situ
    satellite data are commonly in CDF format, remote
    sensing satellite data are typically HDF, NetCDF,
    or CDF.
  • Non-NASA data sources (i.e. NSF, NOAA, DoD) are
    important contributors to the ITM domain.

7
Discovery of Data
  • With the introduction of imaging instruments in
    ITM physics the data volume has exploded. There
    are now terabytes of data in the ITM domain.
  • This talk will focus on (2) discover what data
    sets are available for solving the users
    particular science problem.
  • VITMO uses an approach where external databases,
    calculated events, or other externally generated
    event lists can be used to restrict data searches
    to precise periods of relevance to the user study.

8
The Ability to Find the Appropriate Data Will Be
a Key Requirement of a VITMO
Increasingly satellites in the ITM community will
rely on remote sensing instruments TIMED, DMSP,
NPOESS
9
Typical Researcher Workflow
http//swdcwww.kugi.kyoto-u.ac.jp/index.html
  • Workflow
  • Identify periods of interest (onset of storm,
    etc)
  • Go to various websites to download data from
    different instruments
  • Plot data to identify overlaps in time and space
    of data sets
  • If appropriate data not found repeat loop with
    different time period

http//www.srl.caltech.edu/ACE/ASC/
10
Download Data from Different Websites
11
Check Data from Different Satellites for
Coincidences
April 2 UT
Dec 18 UT
12
Metadata Limits the Searches
  • Typical metadata does not allow the level of
    search that our typical researcher would like to
    make.
  • Typical metadata includes
  • descriptive metadata includes program, satellite
    and instrument information, as well as data
    details like observed phenomena or physical
    parameters measured, units of measure, time and
    spatial coverage (at a broad level only),
    processing level
  • structural metadata defines the details for data
    access and retrieval if selected by the use
  • Typical metadata does not include
  • Time and location information at the pixel level

13
VITMO Search Architecture
VITMO
VITMO Metadata Catalog
ACE
SuperDARN
TIMED
CDAWeb
VSTO
14
Solar Geophysical Indices Database
  • The TIMED program maintains a database of Solar
    Geophysical Indices that the ITM community
    decided were relevant.
  • VITMO queries the TIMED Oracle database directly
    pulling the SGI parameters of interest.
  • We then build windows when all conditions are
    met.

15
Coverlet Windows
Event A 3ltKplt4
Event B Solar Wind Speed gt 400 km/s
Event C Bzlt0
Resultant Timeline
16
What will VITMO search capability mean to users?
  • By taking on a more global view of data, VITMO
    can help the researcher understand the
    connectedness between the different data sets.
  • Example - storm studies - taking the Halloween
    2003 superstorm as a case study.
  • During this event the following things happened
    (1) 3 active regions (ARs) produced a total of at
    least 124 soft X-ray flares and more than 60
    coronal mass ejections (CMEs) between Oct. 18 and
    Nov. 5, 2003. (2) 2 CMEs impacted Earth head-on
    producing huge geomagnetic storms.
  • Today without VITMO
  • A researcher may start with LASCO images and ACE
    solar wind data over the broad time range in
    October and November 2003. If the researcher was
    interested in auroral impacts from the storm they
    may have looked for time periods when Kp was
    between 3 and 9 and Bz was negative.
  • They might have looked for Polar and GUVI imagery
    or auroral conductivity maps during those time
    periods.
  • All of this work would have involved finding and
    navigating numerous web sites that provide data,
    indices, and other information for the specific
    time period.
  • Now with VITMO
  • The researcher will be able to select the needed
    LASCO images and ACE solar wind data.
  • They will also be able to select auroral data
    during the time periods when Kp is between 3 and
    9 and Bz was negative.
  • The VITMO, knowing that the researcher was
    interested in auroral data, would have
    automatically presented GUVI and Polar instrument
    products as appropriate.
  • It would then suggest data readers, appropriate
    for the data format, and tools that the
    researcher could use to work with or analyze that
    data.

17
Data Search Before VITMO
18
Select Coverage
19
Select Physical Parameters
20
Restrict Coverage
21
Select Products for Download
22
Coverage Windows
23
Files Are Packaged Up For Download
24
Applicability to ITM Research
  • Example Using TIMED GUVI data the researcher
    has identified ring current aurora (dayside
    detached arcs, nightside detached aurora, proton
    spots, etc).
  • It is noted that in the cases examined certain
    geophysical conditions occur.
  • Search for all data (from other instruments as
    well) under those conditions to identify
    occurrence frequency.

25
Overcoming the Limits of Our Metadata
GUVI 1356 Å
Plasma bubbles
Limb Scan
74o Inclination
Cross-track scan perpendicular to orbit
Disk Scan
Equatorial arcs
26
Calculated Databases
  • VITMO will employ special coincidence calculators
    that know the viewing geometries of the various
    instruments.
  • The TIMED coincidence calculator is an example of
    a tool which when converted into a web service
    can be used to augment existing data querying.
  • The TIMED coincidence calculator has recently
    been imbedded into the TIMED query system.
  • These calculators will operate as web services
    inside the VITMO query system (or by outside
    query systems).
  • These calculators generate metadata for the
    coincidence of interest which is used by the
    catalog system to answer your query.
  • The metadata generated by this service is
    discarded after it is used hence virtual
    metadata.

27
Not Plotting Tools Imbedded Into Query
28
Coincidence Calculator
29
VITMO Search Architecture
VITMO
VITMO Metadata Catalog
SuperDARN
TIMED
CDAWeb
VSTO
ACE
30
Enhanced Query
  • With the inclusion of virtual metadata sources a
    user can go to VITMO to ask During the last 6
    months where are GUVI EDP products over Millstone
    Hill radar when Kp gt 3.
  • The coincidence calculator will calculate when
    the GUVI product overlaps spatially and
    temporally with Millstone Hill.
  • This is combined with when Kp gt 3.
  • Query is sent to VSTO or MADRIGAL to find
    appropriate radar or other products.
  • All data products returned for download.

31
Enhanced Search Results
  • Addition of virtual metadata capabilities allows
    pre-selection of data for analysis.
  • VITMO search will employ calculator services that
    allow us to deliver results from searches such as
    What GUVI data that contains 23-01 MLT during
    active geomagnetic conditions?

32
Products of Searches Are Windows
  • Products of searches are windows of time.
  • Future products of searches may be products of
    time and space.

33
Find Data During Events
  • Capability exists to search for data from a
    library of events
  • Solar flares
  • Geomagnetic storms
  • User generated conditions
  • Model data comparisons
  • Identify where GUVI electron density profiles
    deviate from International Reference Ionosphere
    calculations in latitudes between 30 mlat by
    more than a factor of two.
  • Now find all DMSP SESS ionospheric data at the
    same time and location.

34
VITMO Search Architecture
VITMO
VITMO Metadata Catalog
SuperDARN
TIMED
CDAWeb
VSTO
ACE
35
Conclusion
  • Addition of SGI databases, on-the-fly calculated
    databases (virtual metadata generators), and
    event listings greatly enhance the search
    capabilities far beyond the limitations of the
    present metadata available to describe products
    in our domain.
  • The VITMO prototype is available at
    HTTP//vitmo.jhuapl.edu.
  • VITMO will be operational at the end of 2007.
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