Date: 1/12/1999
To: OSSE Participants
From: Charlie Flagg
Subject: ADCP Data Conversion Programs

     The ADCP data conversion programs have been updated from the version that
we had at the North Carolina workshop.  To test the routines further, I applied
them to another cruise which had different setup parameters and noted a couple of
problems that had not shown up in the EN302 dataset that we had used.  The most
significant  problem had to do with how the programs dealt with bottom depth. 
The ADCP data acquisition program will gather bottom depth information only
when bottom tracking is enabled.  In addition, there can be times when the ADCP
in unable to determine bottom depth due to a number of extraneous factors.  As a
result, I have modified to program to indicate those profiles gathered without plots
bottom tracking in the QA plots (using a red plus sign) and to eliminate those
profiles from the *.m3d file.  In addition, the program will now
interpolate/extrapolate bottom depths across any gaps in the otherwise usable
ensembles. I have gone over the routines to clean them up and checked for bugs. 
To make things easier, I have also moved all the lines that need to be edited for a
particular cruise/ship up to the main program, adcp4quoddy.m.

     In the use of these programs, it is important that one gives the QA plots close
scrutiny to make sure that things are as you expect them to be.  Two things to
check for are that the velocity profiles and the bottom depths vary relatively
smoothly with time.  If the rotation angle is set wrong there will be quite
noticeable velocity fluctuations produced when the ship changes speed and/or
direction.  If you find periods with bad data, the easiest thing to do is run the
program over the good pieces on either side and then splice the resulting *.m3d
files together later. 

     Lastly, I would appreciate someone running the routines on their machine to
check that I have included all the subroutines that are needed.  I have enough paths
to other directories set up that I can't be quite sure that I haven't forgotten
something.