thumbnail

Variance of discharge estimates sampled using acoustic Doppler current profilers from moving boats

Journal of Hydraulic Engineering

By:
, , , ,
DOI: 10.1061/(ASCE)HY.1943-7900.0000558

Links

Abstract

This paper presents a model for quantifying the random errors (i.e., variance) of acoustic Doppler current profiler (ADCP) discharge measurements from moving boats for different sampling times. The model focuses on the random processes in the sampled flow field and has been developed using statistical methods currently available for uncertainty analysis of velocity time series. Analysis of field data collected using ADCP from moving boats 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 on the order of 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.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Variance of discharge estimates sampled using acoustic Doppler current profilers from moving boats
Series title:
Journal of Hydraulic Engineering
DOI:
10.1061/(ASCE)HY.1943-7900.0000558
Year Published:
2012
Language:
English
Publisher:
American Society of Civil Engineers
Publisher location:
Reston, VA
Contributing office(s):
Office of Surface Water
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Number of Pages:
39