WorkHorse Rio Grande ADCP User's Guide
P/N 957-6167-00 (January 2001)
page 23
13
A Few Principles of Operation
Consult RDI’s Primer (ADCP Principles of Operation: a Practical Primer,
Second Edition for BroadBand ADCPs) to learn more about WorkHorse
principles of operation. The following are a few points from the Primer that
may be worth knowing:
•
Horizontal velocity measurement accuracy is unaffected by
vertical stratification.
•
Stratification has negligible affect on the ability of the
WorkHorse to penetrate through the water; concentration of
suspended particles is the main factor influencing profiling
range.
•
WorkHorse measurements are automatically corrected for
tilts up to
±
20
°
. In addition to correcting for the beam point-
ing angles, the WorkHorse maps depth cells to other cells at
the same depth.
•
If you want to make measurements near the surface from a
bottom-mounted WorkHorse, you should minimize the tilt.
•
Depth cells are most sensitive to velocities at the center of
the depth cell and less sensitive at the top and bottom. This
sensitivity is reflected by what we call a ‘triangular weight-
ing function’. The details of this weighting function are
rarely important for interpretation and use of your data.
•
The actual maximum range can be different from the range
predicted in
Plan
.
Plan
corrects for range variations caused
by temperature and salinity, but it assumes typical scattering
conditions. Weak backscatter can sometimes reduce range
by a factor of two or more.
•
The maximum profiling range decreases with time as the bat-
tery voltage falls. This is because transmit power depends on
battery voltage. Transmit power is optimized for about 13
volts.
Summary of Contents for WorkHorse Rio Grande ADCP
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