Qimera CUBE Filter Soundings Dialog
How to Start
CUBE sub-menu of the Dynamic Grid context menu option in the Project Layer dock.
What it Does
The CUBE Filter Soundings dialog lets you reject soundings based on the current CUBE grid.
General Description
Soundings that are far enough away from the grid based on selected criteria can be marked as rejected. If you have a good CUBE grid this can help eliminate a lot of noisy data in the selected dynamic grid. The Filtering Method lets you setup this selection criterion. The distance can be based sounding distance from the CUBE grid via several methods including Standard Deviations (actually the CUBE Uncertainty) of the data in a cell, in Meters, or by a combination of both (if either passes then the sounding will be rejected). A second option lets you filter based on the computed IHO Depth Uncertainty whereby the expected maximum uncertainty of a sounding is computed based on the parameters provided and if the soundings uncertainty is larger then that it is a candidate to be rejected. By default these selection criteria are based on a flat grid cell. However if you check the Filter Based on Distance from the regional grid slope then the system will calculate the slope of the of a given cell from the selected hypothesis and some of it's neighboring cell's selected hypotheses. From this slope the distance of each sounding is measured perpendicular to the slope. The calculation is more intensive then the flat grid assumption but generally yields superior results. The calculation is more intensive then the flat grid assumption but generally yields superior results.
You can choose to Apply this filter to only soundings above the grid, only below the grid, both above and below, or select different criteria for above and below. If one chooses different criteria for above and below the CUBE grid you will get two tabs for entering the filtering parameters, one for each.
By default the action is to mark soundings as rejected that are selected by the filter however you can reverse the nature of the filter by telling the algorithm to Clear the rejected flag as well. Sometimes this is useful to run the algorithm on an area, if you over filter then change it to clear the rejected flag and run it again to reverse your filter and try again with new parameters. Note however that clearing the rejection flag could bring back soundings which have been previously rejected by other operations. As well as setting or clearing rejected flag, soundings can be marked as suspect or suspect flags cleared.
Return To: CUBE Dialogs
Return To: Dynamic Grid Context Menu