These files contain a timeseries of time, depth, and soundspeed,
matched to the part of the LADCP raw data file when velocities
were valid (i.e. the package was in the water).
Depths were calculated after matching CTD pressure to vertical
velocity from the LADCP profiles.  These shear_Firing processing
files are retained because CTD clocks often drifted substantially compared
to the LADCP clock and there was no synchronization at the time of data
collection. These files are preserved because it would take significant
work to regenerate them.

A yearbase and header was added to the original depdnup*.asc files,
and then renamed depth_soundspeed_???.txt.

Columns in depth_soundspeed_???.txt
1 - index (-) 1-based index into raw LADCP file
2 - yearbase (year)
3 - decimal_day (days) Jan 1 noon UTC is 0.5
4 - depth (meters)
5 - Speed of Sound in water at depth level (m/s)

file sample: 

#   index  yearbase    decimal_day     depth soundspeed
#    none      year           days    meters        m/s
       50      1995     87.8724306       5.0     1534.3
       51      1995     87.8725463       8.8     1534.4
       52      1995     87.8726620      13.8     1534.5
       53      1995     87.8727778      18.8     1534.5
       54      1995     87.8728935      23.8     1534.6