Variance of Discharge Estimates Sampled Using Acoustic Doppler Current Profilers from Moving Platforms
Publication: Journal of Hydraulic Engineering
Volume 138, Issue 8
Abstract
This paper presents a model for quantifying the random errors (i.e., variance) of acoustic Doppler current profiler (ADCP) discharge measurements from moving platforms associated with different sampling times. The model focuses on the random processes in the sampled flow field and has been developed using statistical methods that are currently available for the uncertainty analysis of velocity time series. Analysis of field data that were collected using ADCP from moving platforms from three natural rivers of varying sizes and flow conditions shows that, even though the estimate of the integral time scale of the actual turbulent flow field is larger than the sampling interval, the integral time scale of the sampled flow field is in keeping with the sampling interval. Thus, an equation for computing the variance error in discharge measurements associated with different sampling times, assuming uncorrelated flow fields, is appropriate. The approach is used to help define optimal sampling strategies by choosing the exposure time required for ADCPs to accurately measure flow discharge.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors acknowledge the funding and support from the USGS, Office of Surface Water. They also gratefully acknowledge Dr. Chris Rehmann, Iowa State University, for his constructive comments that inspired this work.
The use of trade, product, or firm names in this paper is for descriptive purposes only and does not imply endorsement by the U.S. government.
Disclaimer
Use of trade, product, or firm names in this paper is for descriptive purposes only and does not imply endorsement by the U.S. government.
References
Bendat, J., and Piersol, A. (2000). Random data: Analysis and measurement procedures, 3rd Ed., Wiley, New York.
Czuba, J. A., and Oberg, K. A. (2008). “Validation of exposure time for discharge measurements made with two bottom-tracking acoustic Doppler current profilers.” Proc., IEEE/OES/CMTC 9th Working Conf. on Current Measurement Technology, IEEE, Washington, DC, 245–249.
García, C. M., Cantero, M. I., Niño, Y., and García, M. H. (2005). “Turbulence measurements with acoustic Doppler velocimeters.” J. Hydraul. Eng.JHEND8, 131(12), 1062–1073.
García, C., Jackson, P., and García, M. (2006). “Confidence intervals in the determination of turbulence parameters.” Exp. FluidsEXFLDU, 40(4), 514–522.
Gonzalez-Castro, J., and Muste, M. (2007). “Framework for estimating uncertainty of ADCP measurements from a moving boat by standardized uncertainty analysis.” J. Hydraul. Eng.JHEND8, 133(12), 1390–1410.
Heskestad, G. (1965). “A generalized Taylor hypothesis with application for high Reynolds number turbulent shear flows.” J. Appl. Mech.JAMCAV, 32(4), 735–739.
Mueller, D. S., Abad, J. D., García, C. M., Gartner, J. W., García, M. H., and Oberg, K. A. (2007). “Errors in acoustic Doppler profiler velocity measurements caused by flow disturbance.” J. Hydraul. Eng.JHEND8, 133(12), 1411–1420.
Mueller, D. S., and Oberg, K. A. (2011). “Discussion of ‘Near-transducer errors in ADCP measurements: Experimental findings’ by Marian Muste, Dongsu Kim, and Juan A. Gonzlez-Castro.” J. Hydraul. Eng.JHEND8, 137(8), 863–866.
Mueller, D. S., and Wagner, C. R. (2006). “Application of the loop method for correcting acoustic Doppler current profiler discharge measurements biased by sediment transport.” USGS Scientific Investigations Rep. 2006-5079, Reston, VA.
Mueller, D. S., and Wagner, C. R. (2009). “Measuring discharge with acoustic Doppler current profilers from a moving boat.” USGS Techniques and Methods Rep. 3A-22, Reston, VA.
Muste, M., Kim, D., Hotchkiss, R., and Gonzalez-Castro, J. (2010). “Near-transducer errors in ADCP measurements: Experimental findings.” J. Hydraul. Eng.JHEND8, 136(5), 275–289.
Muste, M., Vermeyen, T., Hotchkiss, R., and Oberg, K. (2007). “Acoustic velocimetry for riverine environments.” J. Hydraul. Eng.JHEND8, 133(12), 1297–1298.
Nezu, I., and Nakagawa, H. (1993). Turbulence in open channel flows (IAHR monographs), Taylor & Francis, London.
Nikora, V., and Goring, D. (1998). “ADV measurements of turbulence: Can we improve their interpretation.” J. Hydraul. Eng.JHEND8, 124(6), 630–634.
Oberg, K. A., Morlock, S. E., and Caldwell, W. S. (2005). “Quality-assurance plan for discharge measurements using acoustic Doppler current profilers.” USGS Scientific Investigations Rep. 2005-5183, Reston, VA.
Oberg, K., and Mueller, D. (2007). “Validation of streamflow measurements made with acoustic Doppler current profilers.” J. Hydraul. Eng.JHEND8, 133(12), 1421–1432.
Taylor, J. R. (1997). An introduction to error analysis: The study of uncertainties in physical measurements, 2nd Ed., University Science Books, Sausalito, CA.
Teledyne RD Instruments. (2009). WinRiver II user’s guide, San Diego.
Tennekes, H., and Lumley, J. L. (1972). A first course in turbulence, MIT Press, Cambridge, MA.
USGS. (2002). “Policy and technical guidance on discharge measurements using acoustic Doppler current profilers.” Technical Memorandum 2002.02, USGS, Office of Surface Water, Washington, DC. 〈http://water.usgs.gov/admin/memo/SW/sw02.02.html〉 (Jan. 23, 2012).
USGS. (2006). “Availability of the report ‘Application of the loop method for correcting acoustic Doppler current profiler discharge measurements biased by sediment transport’ by David S. Mueller and Chad R. Wagner (Scientific Investigations Report 2006-5079) and guidance on the application of the Loop Method.” Technical Memorandum 2006.04, USGS, Office of Surface Water. 〈http://water.usgs.gov/admin/memo/SW/sw06.04.html〉 (Jan. 23, 2012).
Wernersson, E., and Trägårdh, C. (2000). “Measurements and analysis of high-intensity turbulent characteristics in a turbine-agitated tank.” Exp. FluidsEXFLDU, 28(6), 532–545.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 138 • Issue 8 • August 2012
Pages: 684 - 694
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Mar 26, 2011
Accepted: Apr 12, 2012
Published online: Apr 14, 2012
Published in print: Aug 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.