In Reply Refer To:  
Mail Stop 415

April 25, 2014



SUBJECT: Publication of Version 2, December 2013 of the Techniques and Methods Report Book 3–Section A22 “Measuring Discharge with Acoustic Doppler Current Profilers from a Moving Boat” and associated policy and guidance for moving boat discharge measurements

This memorandum announces the availability of Version 2, December 2013 of Techniques and Methods, 3–A22, Measuring Discharge with Acoustic Doppler Current Profilers from a Moving Boat. This report supersedes policy and guidance provided in Version 1, 2009 and supersedes or duplicates the policy and procedures of memoranda focused on hydroacoustics prior to and including Office of Surface Water Technical Memorandum 2012.01.  A list of these memoranda is provided in the Forward of TM 3–A22.  Thus, Version 2 of TM 3–A22 should be referenced for policy and guidance, rather than earlier memoranda.  The development of new and improved ADCPs is ongoing, as is research and knowledge gained from practical field experience.  Therefore, it is likely that guidance on the application of ADCPs will change and future revisions to USGS policy and guidance will be necessary.  ADCP users are encouraged to log onto the USGS Office of Surface Water Web site [] for the latest guidance and technical memoranda to ensure that the best techniques are being used in collecting and processing ADCP discharge measurements.

 Summary of Changes and Updates

 The list below contains information on the important updates and changes in this revision when compared to the original publication (2009).  The list is not exhaustive, but is intended to highlight differences of interest to the majority of those that perform moving-boat ADCP discharge measurements.  A more comprehensive list with associated page numbers is provided in the section Significant Updates and Changes in the front portion of TM 3–A22.


Shaun Wicklein
Acting Deputy Chief, Office of Surface Water

Distribution:  GS-W All