The ATSR Project
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ATSR FAQ
Q: Help! There's something wrong with my ATSR data!
Q: Which version of Sadist was used to produce my data?
Q: Why does my UCOUNT/UBT/GBT/GBROWSE/GSST image contain negative temperatures?
Q: My GSST image contains SSTs even over land and where there are clouds. What do they mean?
Q: Help! There's something wrong with my ATSR data!
A: Take a look at the ATSR troubleshooting documentation in the documentation section.
Q: Which version of Sadist was used to produce my data?
A: A html version of the Sadist version log has been prepared and placed on the ATSR Software page.
Q: Why does my UCOUNT/UBT/GBT/GBROWSE/GSST image contain negative temperatures?
A: There are two answers to this.
Small negative values (-1 to -8, I think) are 'exceptional values' used to flag errors and other special conditions. Larger negative values are negated temperatures.
These flag either the presence of a 'blanking pulse', indicating that another ERS-2 instrument is active (principally the SAR/scatterometer, I think) or, in gridded products, that the the pixel was cosmetically filled. Much of this information is repeated in the confidence word. See the SADIST-1/2 manuals for further details.
Q: My GSST image contains SSTs even over land and where there are clouds. What do they mean?
A: The SST algorithm is applied to all forward and nadir view GBT pixels, so SSTs in the presence of cloud or over land are meaningless. Users should refer to the corresponding cloud-clearing and land-flagging word to mask the SST data.
Page last modified : Tuesday, 04-Dec-07