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Particle Image Velocimetry Results

Metadata Updated: November 12, 2025

This child item contains the Mathworks Matlab mat-file outputs from the scripts described in the Ancillary Scripts child item. Each file contains the results for a particular field site. See the FGDC metadata Process Steps section for more information about opening these files. The mat-files included here have a standard set of output variables and include a variable named "zzVariableDescriptions" in each mat-file which describes the contents of the file. The following variables and descriptions are included in each mat-file (extracted from the "zzVariableDescriptions" variable): <br> <ul> <li><strong>calibration_distance:</strong> The distance between calibration points in meters.</li> <li><strong>calibration_points:</strong> Pixel coordinates of the calibration points. Format (array): [X1,Y1; X2; Y2]</li> <li><strong>calibration_time:</strong> Time increment between image frames in milliseconds.</li> <li><strong>caluv:</strong> Correction factor used to convert pixel/second into meters/second.</li> <li><strong>calxy:</strong> Pixel ground resolution in meters/pixel.</li> <li><strong>directory:</strong> Path to folder containing images used in PIV analysis.</li> <li><strong>filenames:</strong> Cell array of strings containing image frame filenames. Format (cellarray): 1m (m: number of frames)</li> <li><strong>imagesLocation:</strong> Path to folder containing images used in PIV analysis.</li> <li><strong>i:</strong> Dimensions of PIV results. Format: inumber of rows along y-axis</li> <li><strong>j:</strong> Dimensions of PIV results. Format: jnumber of columns along x-axis</li> <li><strong>k:</strong> Dimensions of PIV results. Format: knumber ofimages or frames in time (numbmer of images processed)</li> <li><strong>p:</strong> PIVLab image pre-processing settings. See PIVLab documentation for information.</li> <li><strong>pixel_resolution:</strong> Pixel ground resolution in meters. Assumes square pixels.</li> <li><strong>r:</strong> PIVLab post-processing settings. See PIVLab documentation for information.</li> <li><strong>resultsFileFullPath:</strong> Path to folder containing PIV results in mat-file format.</li> <li><strong>s:</strong> PIVLab standard processing settings. See PIVLab documentation for information.</li> <li><strong>typevector:</strong> Array (mnp) containing raw vector result type of frame (mn) for each frame (p). Format: type 1-valid PIV vector; type 0-masked vector; type 2-invalid PIV vector</li> <li><strong>typevector_filt:</strong> Array (mnp) containing filtered vector result type of frame (mn) for each frame (p). Format: type 1-valid PIV vector; type 0-masked vector; type 2-invalid PIV vector</li> <li><strong>u_mean:</strong> Array (mn) containing the temporal average u component of velocity in meters/second. Values are averaged for every vector for each frame (along p dimension).</li> <li><strong>u_stack:</strong> Array (mnp) containing filtered u component velocities for each vector (mn) for each frame (p).</li> <li><strong>v_mean:</strong> Array (mn) containing the temporal average v component of velocity in meters/second. Values are averaged for every vector for each frame (along p dimension).</li> <li><strong>v_stack:</strong> Array (mnp) containing filtered v component velocities for each vector (mn) for each frame (p).</li> <li><strong>x_ground:</strong> Array (mn) containing the x (horizontal) ground coordinate in meters for each PIV result vector. Origin of coordinates is the lower left corner.</li> <li><strong>x_pixel:</strong> Array (mn) containing the x (horizontal) pixel coordinate for each PIV result vector.</li> <li><strong>y_ground:</strong> Array (mn) containing the y (horizontal) ground coordinate in meters for each PIV result vector. Origin of coordinates is the lower left corner.</li> <li><strong>y_pixel:</strong> Array (mn) containing the y (horizontal) pixel coordinate for each PIV result vector.</li> <li><strong>zzVariableDescriptions:</strong> A structured array containing elements named after each variable in this dataset.</li> </ul> <br> Each Field Site is abbreviated in various files in this data release. File and folder names are used to quickly identify which site a particular file or dataset represents. The following abbreviations are used: <ul> <li>ACR: Androscoggin River, Auburn, Maine, USA</li> <li>AFR: Agua Fria River, near Rock Springs, Arizona, USA</li> <li>CCC: Coachella Canal above All-American Canal Diversion, California, USA</li> <li>CMC: Cochiti East Side Main Channel, near Cochiti, New Mexico, USA</li> <li>GLR: Gila River near Dome, Arizona, USA</li> <li>RMC: Reservation Main Canal near Yuma, Arizona, USA</li> <li>SMC: Sile Main Canal (at head) at Cochiti, New Mexico, USA</li> <li>WMD: Wellton-Mohawk Main Outlet Drain near Yuma, Arizona, USA</li> </ul>

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date September 12, 2025
Metadata Updated Date November 12, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 12, 2025
Metadata Updated Date November 12, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-61eb31cfd34e8b818ada914b
Data Last Modified 2022-02-14T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 76f02d74-bbdc-4b15-ba85-83e7b10f5efb
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -114.94343, 32.71551, -70.2241, 44.0947
Source Datajson Identifier True
Source Hash ee185cddc4ac722a2cd94e3575272b422982a923351dd785bfa52b89a4551a01
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -114.94343, 32.71551, -114.94343, 44.0947, -70.2241, 44.0947, -70.2241, 32.71551, -114.94343, 32.71551}

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