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.
Summary Table
The table at the top of the window allows the user to select which transect to graph (by clicking on the desired row), provides information on the number of ensembles that have been determined to be invalid by the various filters, and shows the effect of a filter change on the computed discharge. Cells in the table contain color codes associated with cautions or warnings generated from the ADQA. This table does not have any editable cells. The columns in the table are as follows:
Filename—Filename of the transect.
# Ensembles—Total number of ensembles in the transect.
# <4 Beam—Number of ensembles that had valid bottom track but less than 4 valid beams.
# Invalid Total—Number of ensembles with invalid bottom track velocity.
# Invalid Orig Data—Number of ensembles that had invalid bottom track velocity prior to any filtering.
# Invalid <4 Beam—Number of ensembles with valid bottom track but less than 4 beams for which the bottom track velocity has been determined to be invalid by the 3 Beam Solutions Filter.
# Invalid Error Vel—Number of ensembles that have been determined to be invalid due to filtering based on the bottom track error velocity.
# Invalid Vert Vel—Number of ensembles that have been determined to be invalid due to filtering based on the bottom track vertical velocity.
# Invalid Other—Number of ensembles that have been determined to be invalid due to filtering using other filters.
Discharge Prev. —Total discharge prior to most recent filter change.
Discharge Now—Total discharge after applying the most recent filter change. If no filters have been changed, the discharge now will equal the discharge previous.
Discharge % Change—The percent difference between the discharge previous and the discharge now due to the last filter change.
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)
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.
The Nav Ref panel that shows the current navigation or boat velocity reference. If this reference is not BT, then changes to the BT filters will not change the discharge.