[Acoustics] mode use for slow vel

[David S. Mueller]

Reduction in the 25 cm blanking distance will likely result in measuring
velocities near the transducer that a biased low due to the flow disturbance
caused by the instrument and the effect of the flow pattern on the computed
horizontal and vertical velocities.

 

David S. Mueller

U.S. Geological Survey

Office of Surface Water

9818 Bluegrass Parkway

Louisville, KY 40299

 

dmueller at usgs.gov

 

Voice: 502-493-1935

Fax: 502-493-1909

Mobile:502-558-5907

 

  _____  

From: acoustics-bounces at simon.er.usgs.gov
[mailto:acoustics-bounces at simon.er.usgs.gov] On Behalf Of Branford, Tim
(DWLBC)
Sent: Wednesday, September 13, 2006 6:59 PM
To: David M Hernandez; acoustics at simon.er.usgs.gov
Subject: RE: [Acoustics] mode use for slow vel

 

Mode 11 would suit these conditions more and give you high repeatability as
long as you keep your speed below that of the water speed.  Also you might
look at reducing the blanking distance to measure more of the profile in
these shallow depths.

 

Tim Branford 
Technical Officer, Surface Water 
Knowledge and Information Division 
South Australian Department of Water, Land and Biodiversity Conservation 

-----Original Message-----
From: acoustics-bounces at simon.er.usgs.gov
[mailto:acoustics-bounces at simon.er.usgs.gov]On Behalf Of David M Hernandez
Sent: Thursday, 14 September 2006 2:20 AM
To: acoustics at simon.er.usgs.gov
Subject: [Acoustics] mode use for slow vel


To all, The conditions are: Channel width 100 to 200 ft. Depth 3 to 7 ft.
velocity < .1ft/sec. Used Rio 1200khz water mode 12sb bottom mode 5. Not
sure it was the best combination for those conditions, does anyone have
similar conditions? Which mode combinations would work best for collecting
repeatable transects?
Dave

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