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                    R E A D M E 

                    doc: Thu Dec 30 01:20:33 2010

                    dlm: Thu Dec 30 01:24:55 2010

                    (c) 2010 A.M. Thurnherr

                    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

correction based on CTD acceleration. This version allows the

correction to be specified as a polynomial of arbitrary order,

separately for the down and upcast. The quality can be assessed by

comparison with bottom-tracked w profiles and, to a lesser degree, by

comparison with the "diagnostic w profiles" derived with the shear

method. Some preliminary findings based, primarily but not

exclusively, on the P403 yoyo data:

1) The surface-wave acceleration correction considerably improves the

cast-to-cast consistency of vertical velocity profiles.

2) It appears better to use a single correction derived from several

casts, rather than a cast-based correction.

3) A linear fit seems to work better than a higher-order fit.

4) Based on DIMES UK2 stations, it appears that a near-constant winch

speed is required for this to work.

5) The method appears not to work for data sets collected with large

rosettes. This is presumably due to package-induced pressure effects.

Since the best validity test I have been able to come up with is based

on bottom tracked w profiles, I decided to fold the BT code from the

shear method into this code. I save the current version, just in case.