Water Resources Applications Software

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Summary of MEASERR

       measerr - A program for determination of error in individual
                 discharge measurements

       The uncertainty, or standard error, for individual measurements of
       stream discharge is computed based on a root-mean-square error
       analysis of the individual component errors.  The component errors
       include errors in the measurement of width, depth, and velocity, and
       in computation procedures.  The error in measurement of velocity
       include the uncertainties introduced by the measurement instrument,
       the pulsation of flow in natural rivers, the vertical distribution
       of measurements, and oblique flow.  This error analysis can be used
       to evaluate the uncertainty for most discharge measurements made
       with the vertical axis, cup-type current meter.  The procedures do
       not apply to other types of current meters or other methods such as
       dilution gaging or ultrasonic methods.  A USGS study indicates that
       standard errors for individual discharge measurements can range from
       about 2 percent under ideal conditions to about 20 percent when
       conditions are poor and shortcut methods are used.  Some conditions,
       such as wind, ice, boundary effects, flow obstructions, improper
       equipment, as well as incorrect measuring procedures and
       carelessness, can result in larger errors than indicated by the
       error analysis.

       The standard errors computed are at the 68 percent level of
       significance (one standard deviation from the true value).  That is,
       68 percent of the measurements made under similar conditions are
       expected to differ from the true value by less than one standard
       error.  The MEASERR program computes an estimate of the standard
       error by computing the standard error of the individual error
       components, and then combining these errors in a root-mean-square
       error analysis to compute the overall standard error of the current-
       meter discharge measurement.

       Version 2.5 1994/04/19 - code clean-up and minor bug fixes

       Release V930501 - version for use on DOS-based and the Data General
          AViiON computers

       Release B91.1.0, 6/91, author David Yancey, designed by Robert W.
          Meyer, for Prime minicomputers, language: Fortran 77

       The program prompts the user for all necessary input and alerts the
       user to acceptable ranges of input data.  The required input data
       include: 8- or 15- digit station identifier, optional textual
       description of the measurement station, the measurement number, the
       channel width, the cross-sectional area, the measured mean velocity,
       the current-meter type, if horizontal flow were present, the average
       observation time, the number of verticals measured, the number of
       points measured in the vertical, the measurement type (waded,
       suspended, or acoustic), and the channel-bed type.  MEASERR can also
       retrieve input from discharge-measurement data from a WATSTORE
       OUTWAT retrieval.  Required data not in the OUTWAT retrieval are
       prompted for.  Input data are expected in the U.S. customary units.

       The program displays the computed standard error and stores the
       results in a text file.  This file contains a summary of the input
       data, computed standard error, and corresponding qualitative rating
       (excellent, good, fair, or poor) for each discharge measurement.

       MEASERR is written in Fortran 77 with the following extensions:  use
       of integer*2 declarations and use of adjustable size concatenation
       of strings.  MEASERR uses ANSI escape sequence to position text on
       the screen and thus requires terminal emulation that supports these
       escape sequences (for example, VT100 on UNIX-based systems and
       ANSY.SYS loaded for DOS-based systems).  Generally, the program is
       easily installed on most computer systems.  The code has been used
       on UNIX-based computers and DOS-based 386 or greater computers
       having a math coprocessor and 1 mb of memory.

       Sauer, V.B., and Meyer, R.W., 1992, Determination of error in
          individual discharge measurements: U.S. Geological Survey Open-
          File Report 92-144, 21 p.

       Pelletier, P.M., 1988, Uncertainties in the single determination of
          river discharge: a literature review: Canadian Journal of Civil
          Engineering, v. 15, no. 5, p. 834-850.

       Used in surface-water field and records techniques courses taught at
       the regional level.

       Operation and Distribution:
          U.S. Geological Survey
          Hydrologic Analysis Software Support Program
          437 National Center
          Reston, VA 20192

       Official versions of U.S. Geological Survey water-resources analysis
       software are available for electronic retrieval via the World Wide
       Web (WWW) at:


       and via anonymous File Transfer Protocol (FTP) from:

         (path: /pub/software).
       The WWW page and anonymous FTP directory from which the MEASERR
       software can be retrieved are, respectively:


       If you would like to obtain the price of and (or) order paper copies
       of USGS reports, contact the USGS Branch of Information Services at:

                  U.S. Geological Survey
                  Branch of Information Services
                  Denver Federal Center, Box 25286
                  Denver CO 80225-0286

       To inquire about Open-File Reports or Water-Resources Investigations
                  Tel: 303-202-4210; Fax 303-202-4695

       To inquire about other USGS reports:
                  Tel: 303-202-4700; Fax 303-202-4693

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