ADN Geospatial

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ADN Geospatial Temporal

• March 2004

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Geospatial Purpose

• Describe geospatial coverage of resources where
  resources are
• Curriculum, activities, modules etc.
• Datasets
• Model output
• Visuals (maps, satellite imagery)

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Other Geospatial Characteristics

• Describes location information
• Does not describe individual variables of
  datasets or model output (e.g. ozone, SST)
• Is independent of temporal characteristics
• Development period - Jan 2000 to June 2002 with
  some implementation fixes in Dec 2002

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Geospatial Development Team

• DPC - Katy Ginger, Holly Devaul
• ADL/ADEPT - Linda Hill, Anita Coleman, Tim
  Tierney, Greg Janee and David Valentine
• Colorado School of Mines - Tom Boyd
• NASA - Shelley Olds
• Other sources - Ontario Information and Tech.
  Standards - Metadata Content Spec DC spec

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Geospatial Framework Concepts (1)

1. Overarching Bounding Box - a single overall,
   geometric footprint on the surface of a planet or
   moon in our solar system described with a 4
   vortex box in geographic latitude and longitude
2. Detailed Geometries - detailed geometric
   footprints (polygons, lines, points) within the
   Overarching Bounding Box

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Geospatial Framework Concepts (2)

1. Elevation - the vertical min max of footprints
   (overarching box detailed geos) with reference
   to ground or datum level
2. Planet or other body - the planet or body in our
   solar system for the geospatial footprint

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Geospatial Framework Concepts (3)

1. Place-name tied to coordinates - the name of a
   location that is specified by a footprint (e.g.
   N41, S37, E-102, W-109 is Colorado,
   United States
2. Place-name not tied to coordinates - location
   name not specified by a geospatial footprint
   (keyword searching only)

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Geospatial Framework Concepts (4)

1. Event-name tied to coordinates - the name of an
   event that occurred in the area specified by the
   geospatial footprint (e.g. N45, S22, E-62,
   W-86 is Hurricane Fran in 1996
2. Event name not tied to coordinates - an event
   within an area that is not specified by a
   footprint (keyword searching only)

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Geospatial Framework Concepts (5)

• Objects in space - the location of objects (e.g.
  nebulas) that are not within our solar system
  described using the conventions of
• Right ascension (0 lt hours lt 24)
• Declination (-90 lt degrees lt 90)
• Epoch (50 year steps to redraw celestial grid due
  to equinox progress. epoch1950.0 / epoch2000.0)

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Geospatial Framework Concepts (6)

• Coordinate system -
• a frame of reference specifying the location of
  an object
• DLESE uses overarching bounding box so only
  Geographic latitude and longitude can be the
  coordinate system
• visuals, raw and gridded data use coordinate
  system

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Geospatial Framework Concepts (7)

• Datum - base reference in a coordinate system
  the position of an initial point of origin and
  orientation of an ellipsoid that models the
  surface of the earth in the region of interest.
  Datums apply to coordinate systems
• Horizontal - NAD27, NAD83, ATS77
• Vertical - Sea level ,CGD28-CDN, NAVD29-USA,
  NAVD88, IGLD88
• Global - WGS72, WGS84 (GPS use), PZ-90
• Other and Unknown is allowed

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Geospatial Framework Concepts (8)

• Projection -
• systematic presentation (think 2-D maps) of
  objects on the Earth or the celestial sphere
  using coordinate lines on a flat surface
• different projections represent different parts
  of the Earth better (polar stereographic versus
  satellite)
• only visuals, not gridded or raw data, use
  projection
• Other, Unknown and Does not apply are allowed

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Geospatial Framework Concepts (9)

• Latitudes and Longitudes -
• West longitudes -180 to 0
• East longitudes 0 to 180
• North latitudes 0 to 90
• South latitudes -90 to 0
• All in decimal degrees and not degrees/minutes

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Temporal Purpose Characteristics

• Describe date/time characteristics of resources
• Like geospatial, not meant for individual
  variables rather a broad sense of time
• Is independent of geospatial coverage
• Development period - May 2002 to Dec 2002
• Development team - Katy Ginger, Ethan Davis
  (THREDDS) and the ISO 8601 standard

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Temporal Framework Concepts (1)

• Time AD - the ability to describe date/time
  ranges like
• 1965-06-23 120000Z to 1974
• 1492 to 1505 either with time (in UTC) or not
• Begin and end times must be specified
• Time AD to present - the ability to describe date
  ranges like
• 1996 to Present either with time (in UTC) or not
• Begin time is specified and end time says
  Present

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Temporal Framework Concepts (2)

• Time BC - the ability to describe date ranges
• -8700 to -2500 BC
• Years only, no hourly time
• Time relative - describe time ranges like
• 30 days ago to 0 days ago (present)
• 1.2 billion years ago to 1.0 thousand years ago
• 100 years forward to 1000 years forward (for use
  in modeling climate change)
• Begin end times must be specified

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Temporal Framework Concepts (3)

1. Named time period - the ability to associate
   specified date/time information with a named time
   period like 1920 to 1930, e.g. The Roaring
   20's. Sources for the name must be indicated,
   e.g., cataloger provided
2. Simple time period - the ability to name a
   recurring named time period without associating
   specified date/time information, e.g. spring
   semester, fall

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Framework comparisons are next
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Geospatial Comparison IMS vs. ADN

• Datum NAD83, NAVD 88 and others (contrlled
  vocab)
• Map projections several choices (contrlled
  vocab)
• Coordinate system geographic
• Space planets other objects (nebulas)
• Shapes boxes, points, polygons
• Elevation yes

• The spatial and/or temporal characteristics of
  the resource in free text.
• Formal specification of COVERAGE is currently
  under development.
• Users and developers should understand that use
  of this element is currently considered to be
  experimental. (Sept. 2001)

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Geospatial Comparison DC Qualified vs. ADN

• Datum NAD83, NAVD 88 and others (contrlled
  vocab)
• Map projections several choices (contrlled
  vocab)
• Coordinate system geographic
• Space planets other objects (nebulas)
• Shapes boxes, points, polygons
• Elevation yes

• Datum yes, free text
• Map projections yes, free text
• Coordinate system geographic
• Space none
• Shapes boxes and points only no polygons
• Elevation yes

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Geospatial Comparison FGDC vs. ADN

• Datum NAD83 and NADV 88 only
• Map projections More extensive list
• Coordinate system geographic
• Space none
• Object type raster and vector
• Shapes boxes, points, polygons
• Elevation yes

• Datum NAD83, NAVD 88 and others (contrlled
  vocab)
• Map projections Less extensive list (contrlled
  vocab)
• Coordinate system geographic
• Space planets other objects (nebulas)
• Object type none
• Shapes boxes, points, polygons
• Elevation yes

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Temporal Comparison IMS vs. ADN

• The spatial and/or temporal characteristics of
  the resource in free text.
• Formal specification of COVERAGE is currently
  under development.
• Users and developers should understand that use
  of this element is currently considered to be
  experimental. (Sept. 2001)

• Time AD yes
• Present yes
• Time BC yes in multiple units
• Relative yes
• Named periods yes

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Temporal Comparison DC Qualified vs. ADN

• Time AD yes
• Present yes
• Time BC yes in multiple units
• Relative yes
• Named periods yes
• W3C-DTF yes, dates required to use it

• Time AD yes
• Present sort of done as a named time period
• Time BC sort of done as a named time period
• Relative no
• Named periods yes
• W3C-DTF yes, but dates are not required to use it

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Temporal Comparison FGDC vs. ADN

• Time AD yes
• Present yes
• Time BC yes in multiple units
• Relative yes
• Named periods yes

• Time AD yes
• Present no
• Time BC no
• Relative no
• Named periods yes

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Time and location information

• Searchable in ADN (controlled fields)
• Not searchable in IMS (non-existent)
• Dependent on metadata quality in DC (because free
  text)
• Searchable in FDGC (but time limited to A.D.)
• ADN plays well in the FDGC world
• ADN encompasses the big 3 of geospatial, time
  education for effective search