Transcript Visualization of Ocean Data

Visualization of Ocean
Data
Sources, Websites and Software for
Non-Genius Oceanographers without a
Resident Staff of Wizards & Gurus
SCOR 2006
London
Visualization
Working with earth science datasets IS
visualization
 Both fundamental and complex analyses
of the data (and the quality control
procedures that precede them) must be
viewed graphically in order to understand
patterns and relationships – or to identify
problems
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Credo
A robust, pre-compiled program that you
install with a click and run without handholding & grief is a GOOD THING
 Loose bits and pieces of source code,
requiring licensed platforms, additional
libraries, compiling, UNIX system
adjustments, de-bugging, INI/BAT file
editing, and script writing is BAD
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I’m Giving This Talk, and You Aren’t
PC>Mac>UNIX/Linux is the natural order
of the universe
 Windows is insulting and degrading, but it
works
 Scientists at the cutting edge of ocean
data visualization probably don’t need to
hear this:
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– It may not highlight your favorite software
– It is oriented toward capacity building
The Background Paper
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Format types (15)
Relations between formats and visualization (3)
Specific formats of interest (6)
Integration diagrams (3)
Format conversion (20+)
Programs & projects (8)
Data (500/5000)
Software (27)
The Visualization Paradigm
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SOURCE->MANAGER->VISUALIZER->YOU
– Source – datasets “out there” and on hand
– Manager – dynamic methods to get, subset, reformat and deliver
– Visualizer – user and his/her software
Basis for IODE training in Ostend, Belgium,
using OceanTeacher
 This simple paradigm comes in 3 main flavors:
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MODE 1: Like Mother Used to Make
SourceManagerVisualizer/You
 The main paradigm without frills
 Sources are typical CDs/DVDs and basic,
online collections
 Managers deliver desired data in basic
formats
 Visualizers are just about any ocean
software with graphics
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MODE 1 Examples
WOD01 WOD Select ODV, JOA
 NVODS LAS/FERRET GIS, ncBrowse
 ARGO CORIOLIS ncBrowse, ODV, JOA
 WMO/WWW GTS GRADS
 EOS POET-ESIP HDFView
 VMAP0 FTP VPFImport/GIS
 Public GIS data HTML GIS
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Classic ODV Example
MODIS L2 Data in ODV
Operational Surface Vectors
February currents
from averaged
GDP surface
trajectories*
*But see below
MODE 1 Issues
Format issues predominate
 Climatologies & atlases
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– Often simple grids
– Metadata poor or missing
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Operational Data
– GRIB: modelers love, oceanographers hate
 High priests & gurus
 Worst website interfaces on the Web
– NetCDF: cottage industry of “versions”
– HDF: 4 major versions in NASA format wars
MODE 2: Peekaboo
Source/Manager/Visualizer-------You
 Mainly in the GIS area
 Essentially, the user simply gets pictures
of the data from fancy black boxes
 Limited control over output, as provided
by controls & menus
 Vast majority of IMSs published today do
not provide data
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MODE 2 Examples
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IMS/WMS-------- PNG/JPG graphics
– cannot be captured; underlying shapes and
grids (“features”) are not exposed
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Dynamic “Operational GIS” interfaces
based on OGC
– SEACOOS
– OpenIOOS prototypes
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Many java applets that draw maps from
underlying, server-side databases
WMS: A Tale of 2 Attitudes
Geological data (image only) from a typical IMS; Argo drifters
(annotated point shape) from the Argo Information Center
SeaCOOS: OGC at the Limit
Selected Models
Combined Forecasts
MODE 2: Issues
Data access issues predominate
 Dominance of a single commercial firm
 More copyright hurdles than any other data type
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– $$$$$
Slow emergence of community “marine GIS”
 De facto marine GIS
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– OpenIOOS – images only
– SeaCOOS – images only
Related GIS Issues
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Sudden appearance of GOOGLE/KML
– “Wrapper” for images
– Limited shape capability
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Direct NetCDF and HDFx import
– Nothing implemented yet in open-source
– GDAL possibility for NC not yet explored
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IOC training  Saga for images &
gridding; MapWindow for general use
MapWindow for Earth Data
Coastal deserts of Namibia, visualized from SRTM data
MODE 3: Son of OPeNDAP
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Source------- Manager/Visualizer/You
– OPeNDAP plus really good client end
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All the action is on the client side
– nontrivial learning curve
Full potential of OPeNDAP used
 Levels the playing field for PCs and work
stations, due to stride/step controls
 Data storage and platform capacity issues
for model output
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MODE 3 Examples
OPeNDAP Catalog Items---------------IDV
 THREADS Catalog Items--------ncBrowse
 GCMD Catalog Items------------------ODC
 In other words, many sources of the
special URLs required by these clients
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Near Real-Time Argo Data in
ncBrowse
TS Plot for
Namibia’s EEZ
IDV for Oceanography
MODE 3 Issues
Skill and infrastructure issues predominate
 OPeNDAP Data Connector – never
completed; some features in IDV, but still
needed
 Catalog maintenance is poor because it’s
voluntary
 Lights are on but nobody’s home…system
components frequently broken
 Software solutions tend to be big, complex
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Remaining Technical Issues
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Need for a basic vector-drawing utility for simple
U and V grids
Continued heavy use of GRIB by modelers for
output……time to move on
OPeNDAP cataloging has stalled and NVODS
maintenance is unfunded now
The principal NASA site for color and SST data
(L2,L3) uses HDF4 and not HDF4-EOS
Absence of biological data from this talk is
criminal and needs attention ASAP
Remaining General Issues
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Divide between high-end technical applications
in leading laboratories and the visualizations
needs of compiler- or library-challenged ordinary
folks
– The Microsoft model is not completely evil
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Even greater divide between visualization
capabilities in advanced institutions and in the
developing world
– The WWW provides a good model to follow
– GRIB isn’t easy, but it sure does work
Conclusions
Format proliferation has slowed down in
oceanography, but is not dead
 Visualization methods and tools will continue to
be scattered and disjoint until we focus on an
even smaller family of formats
 OPeNDAP-type approaches provide good
solutions to MODE 1 and MODE 3 issues
 OGC-related work must continue to solve MODE
2 issues
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Recommendations
Common visualization solutions for the global ocean
community
 Targeting a reasonable computer platform for
visualization development
 OPeNDAP-type protocol robustly supported for all data
types
 Small family of common formats
 Non-proprietary path, even at the expense of early
progress
 Inclusion of “formal” data visualization methods in all CB
activities
 Involvement of all SCOR-sanctioned programs
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Thank You
• [email protected]
• oceanportal.org
• oceanteacher.org