Earth Science Data: Why So Difficult?
Assembling a multi-sensor set of data for, say, a volcanic eruption means days of wandering cyberspace to find data and pry it loose from the custom search interfaces that jealously guard it. Following the Search is a slog of weeks reading format and QA documents, then cobbling together code to beat the data into a form that can be used safely in analysis tools. Why so difficult?$%#@^%!???
Above rant to be followed by a (mostly) calm and rational discussion of ways toward a solution.
Interested in learning more about the technologies mentioned in this presentation? Here are some places to go and things to do:
Check out the ESIP Federated Search cluster for distributed search on a shoestring
Explore the wonders of OPeNDAP
- Get ASCII subsets of the data! Go to http://acdisc.sci.gsfc.nasa.gov/opendap/HDF-EOS5/Aura_OMI_Level3/OMAERUVd.003//2010/OMI-Aura_L3-OMAERUVd_2010m0131_v003-2010m0202t014811.he5.html, select the variables of interest and click Get ASCII.
- View Level 3 gridded data in Panoply!
- First, download Panoply, an easy to use Java-based viewer for netCDF, HDF and GRIB data
- Open up Panoply, go to File-> Open Remote File, and paste in the following URL (N.B.: without .html extension): http://acdisc.sci.gsfc.nasa.gov/opendap/HDF-EOS5/Aura_OMI_Level3/OMDOAO3e.003/2004/OMI-Aura_L3-OMDOAO3e_2004m1001_v003-2008m0222t095640.he5. (Hint: Try viewing ColumnAmountO3 with a Map Projection of Azimuthal Equidistant Centered on 0 E, -90 N, for a good look at the ozone hole.)
- Here's a URL that shows a dust storm in the eastern Mediterranean region on 24 Feb 2007: http://acdisc.sci.gsfc.nasa.gov/opendap/HDF-EOS5/Aura_OMI_Level3/OMAERUVd.003/2007/OMI-Aura_L3-OMAERUVd_2007m0224_v003-2009m0714t140856.he5. Plot FinalAerosolExtOpticalDepth500 (Aerosol Extinction Optical Depth at 500 nm).
- Level 2 swath data coming soon to OPeNDAP!! (Allows IDV to display swaths.)
See what you can do with netCDF/CF-1 formatted data
- Convert AIRS L2 Swath to netCDF/CF-1 and view in IDV!
- First, download IDV
- Then, acquire the AIRS data in netCDF form (this URL will execute an on-the-fly reformatting.)
- Then use IDV's Data Chooser to read the data in.
- Select a parameter under 2D-Grids in the Field Selector, and "Color-Shaded Plan View" under Displays. Hint: the CO_total_column parameter under the 2D grids shows carbon monoxide emanating from fires in Greece in Aug 2007.
Take a walk down memory lane with EOSDIS Version 0
Yes, the user interface could have used some work, and it could have been faster, and the protocol was a bit clunky, and... But perhaps ahead of its time for federated search frameworks...
Clynnes 18:41, 3 February 2010 (EST)