11. BT Filters
The BT Filters button opens a window that allows the user to evaluate the bottom track data for each transect and change the filter settings. Filter settings are applied to all transects and cannot be set for individual transects.

The left portion of the Graphics panel is determined from the type of data graphed, which is selected by the user using the radio buttons at the top left of the Graphics panel. Invalid data are identified by red circles.
3 Beam Solutions
![]() Error Velocity
![]() Vertical Velocity
![]() Other (only valid if the Other Filter is set to Smooth)
![]() All
![]() Instructions on moving the Legend.
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![]() The bottom track time series plot is shown except when Other and All are selected above. Instructions on moving the Legend.
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![]() The ship track graph displays the raw (unfiltered and without interpolation) ship track and the processed (filtered and interpolated) ship track. The location and source of invalid data are indicated by symbols shown in the graph legend. The end of the transect is indicated by a black square so the user can determine the direction of boat travel. Instructions on moving the Legend.
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![]() The Beam Filter panel shows the current setting and allows the user to change the filters as necessary from the following options:
Auto—(Default) Evaluates 3 beams solutions using neighboring data to determine the validity of the 3 beam solution. Details are documented in Mueller (2016).
Allow—Allows 3 beam solutions
4 Beam—Allows only 4 beam solutions
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![]() The Error Velocity Filter panel shows the current setting and allows the user to change the filters as necessary from the following options:
Auto—(Default) Use the variance of the error velocity data to automatically set threshold limits for each transect. Details are documented in Mueller (2016).
Manual—Allows the user to enter a threshold value that will be applied to all transects in the measurement.
Off—No error velocity filter is applied.
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![]() The Vertical Velocity Filter panel shows the current setting and allows the user to change the filters as necessary from the following options:
Auto—(Default) Use the variance of the vertical velocity data to automatically set threshold limits for each transect. Details are documented in Mueller (2016).
Manual—Allows the user to enter a threshold value that will be applied to all transects in the measurement.
Off—No error velocity filter is applied.
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![]() The Other Filter panel shows the current setting and allows the user to change the filters as necessary from the following options:
Off—(Default) No spike detection type filter is applied.
Smooth—A locally weighted scatterplot smoothing (LOWESS) filter with a dynamic moving window is applied. Details are documented in Mueller (2016).
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![]() Allows user to zoom, pan, and query the graphs. For more information see Toolbar.
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![]() Allows the user to add a comment. For more information see Comment Button.
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