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1、DRAFT FOR DEVELOPMENT DD ISO/TS 24154:2005 Hydrometry Measuring river velocity and discharge with acoustic Doppler profilers ICS 17.120.20 ? Licensed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD ISO/TS 24154:2005
2、This Draft for Development was published under the authority of the Standards Policy and Strategy Committee ? on 31 March 2006 BSI 2006 ISBN 0 580 48073 9 National foreword This Draft for Development reproduces verbatim ISO/TS 24154:2005. This publication is not to be regarded as a British Standard.
3、 It is being issued in the Draft for Development series of publications and ? is of a provisional nature because the technology is still maturing though the Subcommittee felt that there was a need to have a document available to assist users, manufacturers and other stakeholders. It should be applie
4、d on a provisional basis, so that information and experience of its practical application may be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for the Technical Specification. A
5、review of this publication will be initiated not later than 3 years after its publication by the international organization so that a decision can be taken on its status at the end of its 3-year life. Notification of the start of the review period will be made in an announcement in the appropriate i
6、ssue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international standard, to extend the life of the Technical Specification for another 3 years or to withdraw it. Comments s
7、hould be sent in writing to the Secretary of BSI Subcommittee CPI/113/5, Measuring instruments and equipment, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text. A list
8、of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Corresponde
9、nce Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Summary of pages This document comprises a front c
10、over, an inside front cover, the ISO/TS title page, pages ii to iv, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: London S
11、outh Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO/TS 24154:2005(E) TECHNICAL SPECIFICATION ISO/TS 24154 First edition 2005-11-15 Hydrometry Measuring river velocity and discharge with acoustic Doppler profilers Hyd
12、romtrie Mesure de la vitesse et du dbit des rivires au moyen de profileurs effet Doppler DD ISO/TS 24154:2005 Licensed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii Licensed Copy: London South Bank University, Lond
13、on South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iii Contents Page Foreword iv 1 Scope . 1 2 Normative references. 1 3 Terms and definitions. 1 4 Background. 2 5 Principles of operation. 2 6 Application of acoustic Doppler profilers to measurement of river dis
14、charge 3 6.1 Instrumentation and equipment requirements 3 6.2 Making the measurement. 4 6.3 Computing the measurement 4 7 Factors affecting operation and accuracy . 6 7.1 Characteristics of the acoustic Doppler profiler . 7 7.1.1 Transducers or beams . 7 7.1.2 Size and frequency. 7 7.2 River and cha
15、nnel characteristics 7 7.3 Operator training and experience. 8 8 Verification 8 9 Construction 8 10 Maintenance 9 Bibliography. 10 DD ISO/TS 24154:2005 Licensed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv Forewor
16、d 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 through ISO technical committees. Each member body interested in a subject for which a technica
17、l 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 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of ele
18、ctrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to th
19、e member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of
20、normative document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (I
21、SO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three
22、years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an International Standard or be withdrawn. Attention is drawn to the possibility that some of th
23、e elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TS 24154 was prepared by Technical Committee ISO/TC 113, Hydrometry, Subcommittee SC 5, Instruments, equipment and data management. DD ISO/TS 24154:20
24、05 Licensed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 1 Hydrometry Measuring river velocity and discharge with acoustic Doppler profilers 1 Scope Acoustic Doppler profilers are instruments and software packages us
25、ed to measure water velocity, channel bathymetry, and river discharge. This Technical Specification gives the principles of operation, construction, maintenance and application of acoustic Doppler profilers to the measurement of velocity and discharge, and discusses calibration and verification issu
26、es. It is applicable to open-channel flow measurements with an instrument mounted on a moving vessel. It is not applicable to measurement of liquid flow in small channels or partly-filled pipes using a single Doppler- based flowmeter at a fixed point in the cross section. 2 Normative references The
27、following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 772, Hydrometric determinations Vocabulary and sy
28、mbols 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 772 and the following apply. 3.1 Doppler shift ?general? change in frequency of a sound source as it approaches and recedes from an observer 3.2 Doppler shift ?acoustic Doppler instruments? differ
29、ence or shift in frequency of emitted sound waves as they are reflected back from moving particles in the water 3.3 Doppler-based flowmeter class of instruments that uses the principle of Doppler shift to compute water velocity and discharge NOTE These instruments can be deployed at a fixed point in
30、 a cross section or on a moving vessel. 3.4 acoustic Doppler profiler ADP instrument that uses the principle of Doppler shift to compute water velocity and discharge NOTE The instrument is usually mounted on a vessel that transits across a river channel perpendicular to flow. DD ISO/TS 24154:2005 Li
31、censed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 3.5 ping series of acoustic pulses of a given frequency transmitted by an acoustic Doppler instrument 3.6 ensemble collection of pings NOTE Because the measuremen
32、t results from a single ping have a relatively high error, the results of more than one ping are usually averaged to obtain a single measurement. 3.7 transect collection of ensembles from a single pass across a river, lake, or estuary NOTE When measuring streamflow with an acoustic Doppler profiler,
33、 one transect may constitute a single measurement of discharge. 4 Background Acoustic Doppler instruments for measuring water velocity have been in use for about 25 years, primarily in the study of ocean currents and estuaries. In the late 1980s, acoustic Doppler instruments began to be used to make
34、 velocity measurements from a moving vessel 3, 13. The early instruments were narrow-band acoustic Doppler instruments that required deep water (? 3,4 m), which limited their use to deep rivers and estuaries. In 1992, a more advanced acoustic Doppler instrument, known as a Broadband Acoustic Doppler
35、 Current Profiler, was developed that could be used to measure velocities in shallow waters (as shallow as 1,0 m) with a high degree of vertical resolution (0,10 m). Throughout the 1990s, acoustic Doppler profilers were continually developed and enhanced by several manufacturers. The instruments hav
36、e been refined from very cumbersome and heavy units that were 1 m in length and weighing as much as 50 kg to compact and light units as small as 14 cm long and weighing 7 kg. The acoustic Doppler profilers now include advanced acoustic instrumentation designed specifically for use in rivers and soft
37、ware for real-time and post-processing of river velocity and discharge measurements. Acoustic Doppler profilers (3.3) are routinely used to measure discharge in estuaries, rivers, and canals where conventional discharge-measurement techniques are either very expensive or impossible due to stratifica
38、tion of the flow. They are also routinely used to measure discharge in large rivers, in part because of cost savings and reduced uncertainties due to smaller changes in discharge during the measurement. 5 Principles of operation In moving vessel deployments, the acoustic Doppler instrument is mounte
39、d to a vessel (usually a motorized boat) that moves across the water body perpendicular to the current being measured. Water velocities are measured by the acoustic Doppler instrument, which transmits acoustic pulses along three or four beams at a constant frequency between 75 kHz to 3 000 kHz. The
40、beams are positioned at precise horizontal angles from each other (120 for 3-beam instruments and 90 for 4-beam instruments (see Figure 1). The beams are directed at a known angle from vertical, typically 20 or 30. The instrument detects and processes echoes throughout the water column along each be
41、am. DD ISO/TS 24154:2005 Licensed Copy: London South Bank University, London South Bank University, Mon Dec 11 01:20:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 Figure 1 Schematic diagram of an acoustic Doppler instrument with a 4-beam configuration The difference in frequency (shift) between su
42、ccessive echoes is proportional to the relative velocity between the acoustic Doppler instrument and suspended material in the water that reflects the pulses back to the instrument. This frequency shift is known as the Doppler effect. The acoustic Doppler instrument uses the Doppler effect to comput
43、e a water-velocity component along each beam, and the system software computes water velocity in three directions using trigonometric relations. Velocities are determined at preset intervals called bins along the acoustic path. The instrument setup parameters can be adjusted to optimize the system f
44、or the river cross section being measured. These parameters include the depth cell size, the number of depth cells, the number of pings, and velocity reference commands. The water-velocity measurements incorporate both the true water velocity and the boat velocity. The boat velocity can be measured
45、by using the Doppler shift of separate acoustic pulses reflected from the river bottom. This technique, referred to as bottom tracking, is commonly used; it was first used with early sonar to measure the speed of a moving vessel. In addition to measuring boat velocity, the depth of the river is esti
46、mated from the amplitude of the bottom-track echoes (echoes returned from the bottom). Real-time differential global-positioning systems (DGPS) provide an alternative technique for measuring the boat velocity. When the acoustic Doppler instrument is being used to measure discharge, it transmits a se
47、ries of acoustic pulses known as pings (3.5). Pings for measuring water velocities are known as water pings, and pings for measuring the boat velocity are known as bottom-tracking pings. Normally, water pings and bottom-tracking pings are interleaved during transmission. A group of these interleaved
48、 water and bottom-tracking pings are referred to as an ensemble (3.6). The user sets the number of water and bottom-tracking pings per ensemble. An ensemble is analogous to one vertical in a conventional discharge measurement. For example, a typical ensemble is composed of a combination of water pin
49、gs and bottom-tracking pings. The velocities and depths measured for each ping are averaged to yield a single velocity profile and depth for each ensemble. In a conventional discharge measurement, velocity is measured at one point in the vertical when the depth is less than 0,8 m and two, three or five points in the vertical when the depth is greater than 0,8 m. Depending on its characteristics, an acoustic Doppler profiler can measure velocities every 0,25 m in the vertical, so that one en
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