1. Overview of ADCP “Best Practices” Report
Measuring Discharge with Acoustic Doppler Current Profilers from a Moving Boat
Techniques and Methods Report
Chapter 22 of Book3, Section A

2. Overview Why a Techniques and Methods Report
Organization of the report
Highlight selected topics
Changes to existing policy
Quick-Reference guides and other forms
Availability of printed copies

3. Why and How
COE funded development of two guidance reports for ADCP use
Discharge
Velocity Mapping
Revised more general COE report to USGS specific T&M
USGS specific policy
StreamPro
Updated with latest guidance

4. Source of Material Little “new” information
Consolidated information from:
QA/QC report
OSW Technical Memos
ADCP Training Classes
Hydroacoustic Updates
Added some changes to guidance based on latest experience
Published to allow additional updates without republishing entire report

5. Organization Main Body contains guidance Appendices contain details
Predeployment Preparation
Field Procedures
Office Procedures
Appendices contain details
Basic ADCP Operational Concepts
Collecting Data in Moving-Bed Conditions
Description of Water Modes
Beam-Alignment Tests
Forms and Quick-Reference Guides
Measurement Review Procedures

6. A) Excessive Backscatter B) Excessive Attenuation
Predeployment
Understand basic limitations of ADCP
Apply ADCP limitations to site selection and expected performance in the field
Sediment
Unmeasured areas
Configuration
Compass
A) Excessive Backscatter
B) Excessive Attenuation

7. Predeployment – cont. Instrument Quality Assurance Beam Alignment Test
Recommended
1st acquired
After factory repair
After firmware or hardware upgrades
Periodically
Detailed procedures in Appendix D
Typically for Rio Grandes and RiverSurveyors
Periodic Instrument Comparison

8. Predeployment – cont. Ancillary Equipment
GPS
VTG and GGA
Echo Sounder
Deployments and Mounts
Other Equipment
Final Equip Preparation and Inspection
Verify all computer connections and communications before going to the field!!

9. Checklist in Appendix E

10. Field Procedures Site Selection Pre-Measurement Field Procedures
Maybe the most important thing you do in the field.
Location, shape, velocity, other
Pre-Measurement Field Procedures
Set clock
Diagnostic tests
Speed of sound (temp and salinity)
Compass calibration
Instrument configuration
Use wizards
Moving-bed tests

11. Policy Change
USGS policy (U.S. Geological Survey, 2002b; Oberg and others, 2005) requires that a moving-bed test be conducted prior to making a discharge measurement. In USGS training classes and in Oberg and others (2005), an exception to conducting a moving-bed test with every measurement was allowed if sufficient documentation was provided
in the field folder to justify not conducting a moving-bed test. Field experience has shown that sediment transport characteristics can vary greatly for the same discharge, depending on the hydrograph shape, source of runoff, and season of the year. Thus, a moving bed may be detected at a location and discharge where one was not previously detected, or a moving bed may no longer exist at a location and discharge where one was previously detected. Moving-bed conditions also have been observed in low-velocity environments (less than 1 ft/s) and are likely caused by organic material transported by the water. Therefore, to ensure the quality of the data collected, every
moving-boat measurement made with an ADCP must have a recorded moving-bed test. If a site routinely has a moving bed and GPS is always used with the ADCP, a moving-bed test is still required but need only be 5 minutes in length. This requirement supersedes Oberg and others (2005) and various USGS training materials.

12. Moving-Bed Test Requirements
Loop test preferred
Stationary tests
When
If compass calibration is not good
If bottom tracking cannot be maintained
StreamPro
How
5-minutes in duration
With GPS
From a tagline or bridge or anchored
10-minutes in duration
No GPS from manned or RC-boat
These criteria supersede the guidance on stationary moving-bed tests that have been published previously in U.S. Geological Survey (2002b) and Oberg and others (2005).

13. Field Procedures – cont.
Discharge Measurement Procedures
No changes to existing guidance
Step by step quick-reference guides in Appendix E
Post-Measurement Field Procedures
An 8-pass measurement due to one or more transects being >5% from mean does not constitute a check measurement
Check measurements are required according to criteria in WSP 2175

14. Office Procedures Preventive Maintenance Data Storage
Saves time in the long term!!!
Data Storage
Follow office policy
Put data on server (usually within 72 hours)
Measurement Review
Data-Quality Indicators
Commonly Observed Problems

15. Measurement Review Field forms complete, understandable, and legible.
Electronic files backup in field and archived in office.
Number of transects appropriate and in reciprocal pairs.
Configuration
Correct and appropriate
User input agrees with field form
Edge, top, and bottom extrapolations appropriate

16. Measurement Review – cont.
Independent temperature measurement recorded and checked.
Salinity measured and recorded.
Moving-bed test recorded and appropriate procedures used.
Slow smooth boat operation.
Edge distance measured, recorded, and consistent with electronic data.
Number and location of missing or invalid ensembles are acceptable.

17. Measurement Review – cont.
Number and location of invalid depth cells are acceptable.
Top and bottom extrapolation methods have been reviewed and are appropriate.
Measurement computations, including mean discharge and measurement gage height, are correct.

18. Missing and Invalid Data
WinRiver II
RiverSurveyor

19. Ambiguity Errors

20. Signal Attenuation

21. Beam Impinging on Wall

22. Smooth Boat Operation
WinRiver II
RiverSurveyor

23. Spikes in Streambed

24. Bad GPS

25. Appendix A – Basic Concepts
Doppler Concepts
Narrowband and Broadband
Computing Velocity in Orthogonal Coordinates
Measuring a Velocity Profile
Computing Discharge

26. Appendix B- Collecting Data in Moving-Bed Conditions
Cause and Effect of Moving-Bed
Methods to Indentify a Moving Bed
More detail than in main body of report
Stationary, no GPS
Stationary, with GPS
Loop
Methods to Account for Moving-Bed Effects
GPS
Loop method
Multiple moving-bed test method
Mid-section method
Azimuth method

27. Appendix C – Description of Water Modes
SonTek/YSI RiverSurveyor
TRDI
Rio Grande 1
5/11 12
StreamPro
13, C, Low-Noise

28. Appendix D – Beam-Alignment Test
Detailed instructions and criteria for conducting a beam alignment test
Typically only applied to:
Rio Grande
RiverSurveyor

29. Appendix E – Forms and Quick-Reference Guides

30. Rio Grande Quick Sheet

31. RiverSurveyor Quick Sheet

32. Appendix F – Measurement Review Guides

33. Availability PDF version available now Printed version
Linked from
Printed version
3-hole punch, loose leaf
In printing now, available in a couple of months
Announcement memo will be accompany printed version.

34. Questions