source: TI03-DataExtractor/branches/old_stuff/latest_dx/dx/web_extras/help_page.html @ 793

Subversion URL: http://proj.badc.rl.ac.uk/svn/ndg/TI03-DataExtractor/branches/old_stuff/latest_dx/dx/web_extras/help_page.html@793
Revision 793, 1.1 KB checked in by astephen, 13 years ago (diff)

Put all the old code in the old_stuff branch.

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1<HTML>
2<HEAD>
3<TITLE>Help page for the Data Extractor</TITLE>
4<HEAD>
5<BODY>
6<H1>Help page for the Data Extractor</H1>
7<H2><A NAME="interpolation">Interpolation note</A></H2>
8<P>The algorithm currently used under the Data Extractor is the standard CDAT (Climate Data Analysis Tools) method. This can be described as 'area-weighted' or 'conservative'. That is, cell areas are taken into account, and the target cell value is the average of the overlapping source cells, weighted by the area of overlap.
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10<P>Because it is sometimes important that the regridded data preserve the area average of the original data (e.g., when computing global mean net flux at the top of the atmosphere, or total precipitation and evaporation), this algorithm is often preferred over bilinear, bicubic and other methods. The algorithm will therefore generate smoothing when converting to a coarser grid, but not necessarily when converting to a finer grid.
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12<P>This may be replaced in the near future with the SCRIP regridder currently being investigated.
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14<P><A HREF="#top">Return to top of page</A>
15<P>
16</BODY>
17</HTML>
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