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R E A D M E
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doc: Thu Dec 30 01:20:33 2010
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dlm: Thu Dec 30 01:24:55 2010
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(c) 2010 A.M. Thurnherr
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uE-Info: 34 71 NIL 0 0 72 3 2 4 NIL ofnI
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This is the version that I arrived at after implementing a surface-wave
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correction based on CTD acceleration. This version allows the
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correction to be specified as a polynomial of arbitrary order,
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separately for the down and upcast. The quality can be assessed by
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comparison with bottom-tracked w profiles and, to a lesser degree, by
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comparison with the "diagnostic w profiles" derived with the shear
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method. Some preliminary findings based, primarily but not
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exclusively, on the P403 yoyo data:
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1) The surface-wave acceleration correction considerably improves the
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cast-to-cast consistency of vertical velocity profiles.
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2) It appears better to use a single correction derived from several
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casts, rather than a cast-based correction.
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3) A linear fit seems to work better than a higher-order fit.
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4) Based on DIMES UK2 stations, it appears that a near-constant winch
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speed is required for this to work.
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5) The method appears not to work for data sets collected with large
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rosettes. This is presumably due to package-induced pressure effects.
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Since the best validity test I have been able to come up with is based
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on bottom tracked w profiles, I decided to fold the BT code from the
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shear method into this code. I save the current version, just in case.
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