[Coral-List] Doppler Velocity Meter & Corals: Coral-List Digest, Vol 26, Issue 18
cstorlazzi at usgs.gov
Fri Oct 15 14:56:35 EDT 2010
Dana (and colleagues),
We've used a range of instrument, from electromagnetic single-point
current meters and single-point acoustic doppler velocimeters to
acoustic doppler current profilers made by such companies at Marsh-
McBirney, Sontek, RDI, and Nortek. For the record, I don't think
anyone really uses electromagnetic current meters any more, for the
instrument itself disturbs the flow being measured, so pretty much
everyone has gone to acoustics, which also provide some information on
the density of material in the water column (acoustic backscatter),
which is useful for providing insight into sediment, larval, etc
dynamics when calibrated with data from other sensors.
In terms of using a single-point acoustic doppler velocimeter versus
an acoustic doppler current profiler, it really depends on what you're
looking to measure. Single-point acoustic doppler velocimeter provide
the most precise x-y-z (or, with a compass and tilt sensor u-v-w)
currents at one point, and can often sample at much higher rates (~10
Hz) than acoustic doppler current profilers (~1 Hz), thus allowing you
to make measurements of turbulence and other high-frequency processes.
Acoustic doppler current profilers, while not providing accurate z (or
w, heading towards/away from the transducers) currents and lower-
resolution x-y (u-v, flow perpendicular to the transducers) than
acoustic doppler velocimeters, do provide a profile of x-y (u-v) at
set ranges away from the transducer, allowing one to examine the
variability in flow structure (and acoustic backscatter) over some
distance through the water column.
In terms of manufacturers, it's all depends on what you want- ability
to integrate external sensors, broadband capability, ease of use,
etc. I'm guessing you'd get 10 different answers from 10 different
folks; I happy to chat more about this offline, if desired.
Curt Storlazzi, Ph.D.
U.S. Geological Survey
Pacific Coastal and Marine Science Center
400 Natural Bridges Drive
Santa Cruz, CA 95060
(831) 427-4721 phone
(831) 427-4748 fax
Staff web page:
On Oct 15, 2010, at 9:00 AM, coral-list-request at coral.aoml.noaa.gov
> Message: 4
> Date: Thu, 14 Oct 2010 18:06:40 -0400
> From: riddlelabs at aol.com
> Subject: [Coral-List] Doppler Velocity Meter & Corals
> To: coral-list at coral.aoml.noaa.gov
> Message-ID: <8CD3A03364188FB-9DC-5FBC at webmail-d095.sysops.aol.com>
> Content-Type: text/plain; charset="us-ascii"
> Is anyone using a doppler water velocity meter (such as Sontek?).
> I'm hoping to upgrade from my Faraday-based velocity meter and would
> greatly appreciate ANY input.
> Sontek recommends a 10mHz ADP doppler for my applications (field and
> some lab work).
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