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The Surrogate Analysis and Index Developer (SAID) Tool

October 30, 2018


Sediment acoustics composite screens

The Surrogate Analysis and Index Developer (SAID) tool is a stand-alone tool to assist in the creation of ordinary least squares (OLS) regression models by providing visual and quantitative diagnostics to the user. The tool also processes acoustic parameters to be used as predictor variables using a constant spatial suspended sediment concentration method. The method utilizes acoustic backscatter data from fixed-mount stationary acoustic Doppler velocity meters (ADVM).

Within the program, you can:

  • Match observations from multiple time series data set
  • Create linear regression models
  • Compute ADVM backscatter parameters
  • View backscatter profiles
  • View linear model diagnostic statistics and plots
  • Export model information
  • Generate a predicted time series


Match observations from multiple time series data sets

  • Similar method to a left join database operation
  • Matching is done between observations that are closest in time
  • Adjustable maximum allowable time difference between matching observations

Create linear regression models

  • Ordinary least squares regression models
  • Quickly change the variables used in the regression
  • No limit on the number of variables used in the linear model
  • No restrictions to which variables must be used
  • Ability to exclude observations used in the model

Compute ADVM backscatter parameters

  • Modify ADVM configuration parameters
  • Adjust backscatter values and cell range used in the computation
  • Near field correction

View backscatter profiles

  • Plots of measured, water corrected, and sediment corrected backscatter against distance along acoustic axis of beam
  • Simultaneously view multiple observations

View linear model diagnostic statistics and plots

  • Diagnostic statistics
    • Standard linear regression diagnostic statistics
    • Probability plot correlation coefficient
    • Non-parametric smearing bias correction factor
  • Plots
    • SLR scatter plots in transformed and linear space
    • Partial residual plots for MLR
    • Model residual
      • Raw vs. fitted
      • Probability
      • Standardized serial correlation

Export model information

  • Save model information as a MATLAB MAT-file
  • Write model information as a .csv file

Generate a predicted time series


Known Issues

Issue Status Causes and solutions
Error on loading data files with trailing tabs SAID v 1.1 is unable to load data from tab delimited text files with trailing tabs. One cause of the error may be that the entire final column is blank. If the trailing tabs from each line are removed, the program will be able to load data from the file. Another cause may be a blank observation in the final column of the file. Putting a variable that contains an entry for each observation (for instance, a date or time variable) will remedy the issue.



The first two files below are options to install SAID and, if necessary, the required MATLAB Compiler Runtime (MCR) library. The current version of SAID requires 32-bit MCR version R2014a. The other download options include the SAID manual and example data, plus a couple additional utilities.

SAID 1.1 installer, MCR full installer (522 MB) - The MCR is packaged within this installer. Use this installer if you plan on installing without internet connectivity, as the web installer will not run without a connection. It is also recommended to download this file if you don't have the appropriate MCR installed.

SAID 1.1 installer, MCR web installer (2.4 MB) - If the necessary MCR is not already installed, this installer will download and install it. Use this installer if you already have the appropriate MCR version installed. This installer requires internet connectivity to run.

SAID 1.1 Release Notes - See what is updated in the latest version.

SAID manual - Download the SAID manual from the USGS Publications Warehouse.

SAID Example Data (2.0 MB) - Example data that can be used in SAID. Also, included in the Spoon River data directory is a tutorial on using the example data.

ARGcat and Readme (411 KB) - ARGCat, the Argonaut dataset concatenator program, combines several Argonaut datasets read from ViewArgonaut exported ASCII files and exports them as a single SAID readable text file. The SAID program can also combine several Argonaut datasets.



Surrogate Analysis and Index Developer (SAID) Tool

Acoustic Index Methods for Computing SSC

Estimating Suspended Sediment in Rivers Using Acoustic Doppler Meters Fact Sheet


Bug Reports or Suggestions

If you're experiencing a problem with SAID, submit the following information and possibly a graphical representation of the bug.

Please include the following information in an e-mail, and send it to Marian Domanski and Tim Straub, or (see User Group section for more information on subscribing to the ssc_surrogates mailing list)

  1. Contact Information: Name, Phone Number, and E-mail Address
  2. What version of the software are you using?
  3. What operating system are you using?
  4. An explanation of the problem (e.g., "Input data not being read correctly")
  5. If the problem is reproducible, please list the steps required to re-create the problem (e.g., "1. Load Dataset. 2. Insert some text ...)
  6. If the problem is not reproducible (only happened once, or occasionally for no apparent reason) please describe the circumstances in which it occurred and the symptoms observed (Note: it is much harder to fix non-reproducible bugs)
  7. If the problem causes any error messages to appear, please write down the exact text displayed
  8. If you have a SAID dataset that demonstrates the problem, the "Save" option is under the "File" menu on the main SAID window. Send the MAT file that is created from saving

If you want to make a suggestion you can send email to the addresses listed above.

User Group

USGS Suspended-Sediment Concentration (SSC) Mailing List and Forum

The USGS, Office of Surface Water (OSW) maintains a mailing list and the forum relating to the application of surrogate instruments and methods for measurement of suspended-sediment concentration in rivers and estuaries. The mailing list and forum are used to share information about instruments, including policies, procedures, techniques, and new developments within the USGS and other agencies.

Mailing List

The SSC_surrogates mailing list is the primary means for disseminating up-to-date information regarding USGS policies, training classes, workshops, and new developments. A searchable archive of email messages sent to the acoustics mailing list is kept. This archive can be viewed chronologically or by author or subject.

In order to post to the acoustics mailing list, it is necessary to first subscribe to the list. Send an email to with the words "subscribe" and "end" on separate lines in the body of the email. A confirmation email will be sent to you once you are subscribed. Email postings to the list should then be addressed to


The forum is maintained by the USGS, OSW for sharing information regarding the application of surrogates to the measurement of suspended- sediment concentration. The forum is a USGS resource to educate, learn, and facilitate the exchange of information about applications involving a variety of instruments including acoustics, turbidity, laser diffraction, and other technologies. The forum is also used by the USGS to disseminate important information regarding quality assurance practices, training, and other matters.

Registration is required to access the forum.


Suggested Citation

Domanski, M.M., Straub, T.D., and Landers, M.N., 2015, Surrogate Analysis and Index Developer (SAID) tool (version 1.0, September 2015): U.S. Geological Survey Open-File Report 2015–1177, 38 p.,



Publication Year 2018
Title The Surrogate Analysis and Index Developer (SAID) Tool
Product Type Software Release
Record Source USGS Digital Object Identifier Catalog