What is HDF-EOS?
Information compiled
from HDF-EOS Workshop II
HDF-EOS Workshop III, 1999
ESDIS Project, Code 423
NASA/Goddard Space Flight Center
Greenbelt MD 20771 USA
HDF-EOS
• HDF-EOS defines standard “profiles” for the
use of HDF in the domain of Earth Observing
Data.
• HDF-EOS is a higher level library built on top
of HDF structures and functions.
• Geolocation information is coupled to data for
common data collection profiles of Point,
Swath and Grid.
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HDF-EOS Point
• Intended use
– Discrete points in time
and/or location.
– Table of data linked to
table of geographic
information.
– 8-level Hierarchical, each
level may contain indices
to the level below
HDF-EOS, 1999
Latitude
Longitude
Temperature oC
Dew Point
o
C
61.12
-149.48
15.00
5.00
45.31
-122.41
17.00
5.00
38.50
-77.00
24.00
7.00
38.39
-90.15
27.00
11.00
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HDF-EOS Point
Latitude
25.2645
22.3549
23.2564
Longitude
091.2564
-93.4657
-89.2546
Buoy_ID
0126
3564
1256
Hierarchical links:
• Every level in a Point
data set must be linked
into the hierarchy.
• Before two levels can
be linked, a link field
must exist
HDF-EOS, 1999
Buoy
_ID
0126
0126
3564
1256
1256
0126
3564
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Time
01:26
05:56
06:28
08:12
09:58
09:59
10:16
Wave
Height(ft)
2.54
3.58
12.64
7.58
7.76
4.23
10.23
Temp
(C)
18.4
18.2
16.4
17.1
17.2
20.1
17.5
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HDF-EOS Point
• No presently defined data sets from Landsat
or Terra instruments.
• Likely use in validation campaigns.
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HDF-EOS Swath
• Intended use
– Across track scanning
instruments.
– Sounding instruments
– Level 1: Geolocated
Sensor Units
– Level 2: Geophysical
Parameters derived from
Level 1.
Scan Lines
Instrument
Path
Along Track
Instrument
Path
Along Track
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HDF-EOS Swath
Data fields
“Brightness
Temperature”
Dimension
Name: Scan
Size: 16
Dimension
Name: Track
Size: 42
Dimension
Name: Geotrack
Size: 21
Geolocation fields
“Time”
“Latitude”
“Longitude”
Map1
DataDimension: “Track”
Geodimension: “Geotrack”
Offset: 1
Increment: 2
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HDF-EOS Swath
• 74 HDF-EOS Swath Products are defined for
distribution from EOSDIS after Terra launch.
• ASTER, CERES, Landsat 7, MISR, MODIS and
MOPITT
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HDF-EOS Grid
• Intended use
– Variables mapped on
uniform space-time grid
scales
– Level 3 - Gridded single
measurement parameters
– Level 4 - Modeled or
derived from multiple
measurements
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HDF-EOS Grid
Altitude
Size 30
Xdim
Size: 2000
Projinfo
Ydim
Size: 800
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HDF-EOS Grid
Projections Supported
•
•
•
•
•
•
•
Geographic
Transverse Mercator
Universal Transverse Mercator
Hotine Oblique Mercator
Space Oblique Mercator
Polar Stereographic
Lambert Azimuthal Equal Area
HDF-EOS, 1999
• Lambert Conformal Conic
• Polyconic
• Interrupted Goode’s
Homolosine
• Integerized Sinusoidal
Compression Methods
• Run-Length Encoding
• Adaptive Huffman
• Gzip
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HDF-EOS Grid
• 128 HDF-EOS Grid Products are defined for
distribution from EOSDIS after Terra launch.
• ASTER, CERES, ECS Ancillary, MISR, MODIS,
MOPITT
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Product Levels
•
•
Level 0 - Reconstructed, unprocessed
instrument/pay-load data at full
resolution; any and all communications
artifacts, e.g., synchronization frames,
communications headers, duplicate data
removed.
Level 1A- Reconstructed, unprocessed
instrument data at full resolution, timereferenced, and annotated with ancillary
information, including radiometric and
geometric calibration coefficients and
georeferencing parameters, e.g., platform
ephemeris, computed and appended but
not applied to the Level 0 data.
HDF-EOS, 1999
•
•
•
•
Level 1B - Level 1A data that have been
processed to sensor units (not all
instruments will have a Level 1B
equivalent).
Level 2 - Derived geophysical variables at
the same resolution and location as the
Level 1 source data.
Level 3 - Variables mapped on uniform
space-time grid scales, usually with some
completeness and consistency.
Level 4 - Model output or results from
analyses of lower level data, e.g.,
variables derived from multiple
measurements.
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Key
An HDF File
One or more HDF data objects:
– Portability
– Elementary data access
– Basic self-description
One or more HDF-EOS data objects:
– Geolocation information tightly coupled to data
– Fully standardized geographical subsetting
– Moderate self-description
EOSDIS Metadata ODL in a “text annotation”
– ECS ingest, archiving, search, and distribution
– Enhanced self-description
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An HDF file with a set of HDF
data objects
Services Provided
Services Not Provided
• Portability
• Elementary data access
• Basic self-description
• Geolocation information
tightly coupled to the data
• Fully standardized
geographical subsetting
• ECS ingest, archiving,
search, and distribution
• Enhanced self-description
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An HDF file with a set of
HDF-EOS data objects
Services Provided
Services Not Provided
•
•
•
•
• ECS ingest, archiving,
search, and distribution
• Enhanced self-description
Portability
Elementary data access
Moderate self-description
Geolocation information
tightly coupled to the data
• Fully standardized
geographical subsetting
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An HDF file with a mixed set
of HDF-EOS and HDF data
objects
Services Provided
Services Not Provided
•
•
•
•
• ECS ingest, archiving,
search, and distribution
• Enhanced self-description
• Fully standardized
geographical subsetting
Portability
Elementary data access
Moderate self-description
Geolocation information
tightly coupled to some of
the data
• Partially standardized
geographical subsetting
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An HDF file with a set of
HDF data objects with
EOSDIS metadata
Services Provided
Services Not Provided
• Portability
• Elementary data access
• ECS ingest, archiving,
search, and distribution
• Enhanced self-description
• Geolocation information
tightly coupled to the data
• Fully standardized
geographical subsetting
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An HDF file with a set of
HDF-EOS data objects with
EOSDIS metadata
Services Provided
• Portability
• Elementary data access
• Geolocation information
tightly coupled to the data
• Fully standardized
geographical subsetting
HDF-EOS, 1999
• ECS ingest, archiving,
search, and distribution
• Enhanced self-description
Services Not Provided
• None of the above listed
services.
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