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| Range of values | |
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| Minimum: | 15 |
| Maximum: | 570 |
| Units: | seconds |
This dataset includes video and velocity observations of artificial sand and oil agglomerates (acquired with two Canon 7D DSLR cameras) collected during a 2014 USGS small-oscillatory flow tunnel experiment conducted at the Naval Research Laboratory (NRL), Stennis Space Center, Mississippi. The information contained within the videos is needed to capture artificial sand and oil agglomerate incipient motion, and flow velocity at time of incipient motion, under ideal conditions, to test shear stress based incipient motion parameterizations. The information contained within the videos is also needed to capture exhumation and burial processes of artificial sand and oil agglomerates. This dataset contains video of aSOAs in a small-oscillatory flow tunnel from the false-floor experiment, as well as times of incipient motion, aSOA identifiers, graphical representations of observed flow velocity, and graphical representations of calculated shear stress based on observed flow velocity. Observed flow velocities, which provide additional information about aSOA incipient motion, were also collected during this experiment (see 2017_309_DD_FF_velocity_stress.zip) and are included in this data release.
First, velocities were first passed through a MATLAB built-in one dimensional smoothing filter (filter.m) with a window size of ten. Second, the difference was taken between the raw and smoothed time series and the standard deviation of that difference was calculated. Third, points with a difference greater than three times the standard deviation were identified, and replaced with the smoothed signal value at the same time. The first, second, and third, steps were then repeated three times, with the previously de-spiked signal replacing the input each time, which produced final, quality controlled, de-spiked and smoothed de-spiked time series of velocities.De-spiked and smoothed de-spiked records of 3D velocity data, time, and depth information were re-saved in MATLAB readable ‘.mat’ files. De-spiked and smoothed de-spiked velocity data were treated with an additional quality control step.
A measure of signal quality, called Correlation, was recorded by the Vectrino profiler along with the raw data. Correlation is the measure of the data correlation as returned by each of the three acoustic beams of the profiler. Time points with correlation less than 70% are replaced in the record with non-number (NaN) values.Quality controlled records of de-spiked and smoothed de-spiked velocity were saved in MATLAB readable ‘.mat’ files. Person who carried out this activity:
A single JPEG from the video record is read using 'imread'. The single JPEG is rotated 180 degrees, to correct the image orientation. The overall figure is created using 'figure.' The single JPEG from the video record is plotted within the overall figure using 'subplot,' and 'imshow.' The graph of velocity, shear stress, the indicator of the moment of incipient motion, and indicator of current time was plotted using 'subplot,' and 'plot.' The current overall figure is collated as a video frame in a sequence of frames using MATLAB built-in function 'getframe.' The interpretive video product '.avi' file, has one frame added to it using MATLAB built-in function 'WriteVideo' to add the frame created using 'getframe.'Person who carried out this activity:
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Are there legal restrictions on access or use of the data?Access_Constraints: None
Use_Constraints:Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
This digital publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
| Data format: | This dataset provides false-floor experiment incipient motion video data with a graphical representation of flow velocity and shear stress. Images were collected during small-oscillatory flow tunnel laboratory experiments at the Naval Research Laboratory, Stennis Space Center, Stennis Mississippi and includes the associated metadata. in format MP4 (version 1) Mpeg-4 video file Size: 142.7 |
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| Network links: |
https://coastal.er.usgs.gov/data-release/doi-F76D5R69/data/2017_309_DD_FF_video.zip |
This zip file contains data available in mpeg-4 (MP4) video file format. The user must have software capable of reading .mp4 video file format to use these data.