The Moving-bed Test button opens a window that allows the user to review moving-bed test results, mark tests invalid, and decide if any of the moving-bed tests should be used to correct the measured discharge.
When the Moving-bed Test window is first opened, the first file automatically selected as the primary moving-bed test is the file displayed in the graphs at the bottom of the window. To display a different file, click in the table on the filename to be displayed. The filename of the moving-bed test displayed is shown immediately above the graphs. The graphs at the bottom change depending on whether the displayed test is a loop test or a stationary test.
Definition of Table Columns
Filename—The filename containing the moving-bed test.
Type—The type of test (Loop or Stationary). NOTE: The test automatically selected for determining if there is a moving-bed and/or correcting for it are in bold. For details see the section Automatic Test Selection.
Duration—The duration of the test in seconds.
Distance Upstream—The distance the test showed the boat moved upstream from its starting location. This distance is the closure error for a loop test.
Moving-Bed Speed—The computed speed of the bed (Distance Upstream/Duration).
Moving-Bed Direction—The direction (azimuth) the boat moved relative to its starting location. For a moving-bed condition, this value should be approximately 180 degrees from the flow direction. This value is only computed for the loop moving-bed test.
Flow Speed—The magnitude of the average water velocity vector for all data in the test.
Flow Direction—The direction (azimuth) of the average water velocity vector for all data in the test. This value is only computed for the loop moving-bed test.
% Invalid BT—The percentage of ensembles that have invalid bottom track data.
Compass Error—The difference in the flow direction between the outgoing and returning portions of the loop moving-bed test.
% Moving Bed—The ratio of the moving-bed speed to flow speed expressed as a percentage.
Moving Bed—Using the criteria for a moving-bed condition documented in Mueller and others (2013), QRev determines if a moving-bed condition exists. If the quality of the moving-bed test results in errors, this field is set to Unknown because the moving-bed test is unreliable.
Quality—QRev completes a quality assessment of every moving-bed test. Based on criteria documented in Mueller (2016), the quality of the measurement is set to Good if all the quality checks pass, to Warnings if some quality checks fail but are not critical failures, or to Errors if critical errors in the moving-bed test are identified.
User Valid
The User Valid column lets the user identify tests that the user considers valid moving-bed tests. QRev assumes that all loaded tests are valid tests; for example, tests that were completed using proper technique. If a test is not valid because of an aborted test or because of something that happened during the test that indicates the test should not be used, the user should uncheck that test. Unchecking the User Valid column tells QRev that this test should not be used to determine if a moving-bed condition exists or to correct the discharge.
The Use for Correction column identifies the test or test(s) that will be used to correct the discharge for a moving-bed condition. If bottom track is the navigation reference and a moving bed exists, QRev will automatically select the moving-bed test to use to correct the final discharge; however, the user can override the selection by checking or unchecking the tests. If the user selects to use a moving-bed test that has Errors, the QRev will warn the user but allow the user to override the errors.
If the user chooses Justify and Use a comment must be entered.
QRev does not permit the combined use of loop and stationary tests. No test can be checked or will be applied if a moving-bed condition does not exist or if GGA or VTG are the navigation reference.
The Messages panel lists the warning and error messages from the quality assessment for each moving-bed test. The scroll bar at the right can be used to scroll through the messages.
The graphs displayed depend on whether the test displayed is a loop or stationary moving-bed test.
The two graphs for the loop moving-bed test are a time series of boat speed on the left and a ship track graph on the right. Red circles in the time series graphs identify ensembles with invalid bottom track. Check boxes in the Ship Track panel for the loop moving-bed test can be used to control what data are displayed on the ship track.
The two graphs for a stationary moving-bed test are a time series of the average moving-bed speed on the left and a ship track graph on the right. By the end of a stationary moving-bed test the average moving-bed speed should reach equilibrium, so the line in the left graph should be horizontal or oscillating slightly about a horizontal trend. Red circles in the time series graphs identify ensembles with invalid bottom track. The ship track is graphed so that the horizontal axis is the cross stream distance and the vertical axis is the upstream distance. All velocity vectors should be pointing down. A moving-bed condition would present itself as a ship track in the upstream direction.