ISO INTERNATIONAL STANDARD 24578 First edition 2021-03 Hydrometry Acoustic Doppler profiler - Method and application for measurement of flow in open channels from a moving boat Hydrométrie - Profileurs acoustiques a effet Doppler - Méthode et application pour le mesurage de I'écoulement a surface libre sur un bateaumobile Reference number IS0 24578:2021(E) ISO @ IS0 2021 IS0 24578:2021(E) COPYRIGHT PROTECTED DOCUMENT IS02021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting beloworIso'smemberbodyinthecountryoftherequester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland ii @IS02021-All rightsreserved IS0 24578:2021(E) Contents Page Foreword V Introduction. .vi 1 Scope. .1 2 Normative references. .1 3 Terms and definitions. .1 4 Principles of the boat mounted ADCP method .3 4.1 General 3 4.2 Doppler principle applied to moving objects 4 4.3 Acoustic Doppler current profiler techniques 5 4.3.1 General.. 5 4.3.2 Pulse incoherent. 5 4.3.3 Pulse-to-pulse coherent. 6 4.3.4 Broadband (Spread spectrum) 6 4.4 Measurement of velocity profile. 6 4.4.1 General. 6 4.4.2 Measurement of relative velocity 6 4.4.3 Measurement of boat velocity.. 6 4.4.4 Near boundary data collection 8 4.5 Speed of sound in water. 10 5 Flow determination .11 5.1 General method 11 5.2 Measurement procedure 13 5.3 Method dealing with moving-bed condition without GNsS system 15 5.3.1 General. 15 5.3.2 Stationary moving-bed method 15 5.3.3 Azimuth method. 16 5.3.4 Subsection correction method. .16 5.3.5 Loopmethod .17 5.3.6 Mid-section method .19 6 Site selection .19 6.1 General. 19 6.2 Site-selection criteria .20 7 ADCP Deployment procedure .21 7.1 Deployment techniques. 21 7.1.1 General. .21 7.1.2 Manned boat mounted 21 7.1.3 Tethered boat. 122 7.1.4 Deployment on a remote-control craft 7.1.5 Data retrieval modes. 222 7.2 Operation of boat 7.2.1 Boat path. 7.2.2 Boat speed. 7.3 Field procedures. 7.3.1 Pre-field procedures. 7.3.2 Field setup 7.3.3 Reviewing ADCP data during measurement 26 7.3.4 Post measurement requirements. .26 7.4 Ancillary equipment 27 7.5 Other consideration. 27 7.5.1 Edge distances 27 7.5.2 Depth measurements at sites with high sediment concentrations .27 7.5.3 GNSS compass. 28 @ IS0 2021 - All rights reserved ii IS0 24578:2021(E) 7.6 Maintenance and ADCP checks 28 7.6.1 General 28 7.6.2 Built-in diagnostic check. 28 7.6.3 Periodic major service in the manufacturer 28 7.6.4 Periodic ADCP performance check 28 7.6.5 Physical maintenance 28 7.6.6 Beam-alignment test 28 7.7 Training. .29 8 Uncertainty. 29 8.1 General 29 8.2 Definition of uncertainty 29 8.3 Uncertainties in ADCP measurements - General considerations 30 8.4 Sources of uncertainty 30 8.5 Minimizing uncertainties. 31 Annex A (informative) Velocity distribution theory and the extrapolation of velocity profiles... ...32 Annex B (informative) Determination of edge discharges .34 Annex C (informative) Example of an equipment check list ..36 Annex D (informative) Example of ADCP gauging field sheets ..38 Annex E (informative) Beam alignment test .42 Annex F (informative) Uncertainty evaluation methods .44 Bibliography 45 iv @ IS0 2021 - All rights reserved IS024578:2021(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out throughIsoOtechnicalcommittees.Eachmemberbodyinterested inasubjectforwhichatechnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. IsO colla