Qimera SVP Editor

How to Start

  • Edit SVP option from Tools menu of Main Menu bar
  • Context menu of SVP data

What it Does

The SVP Editor is used to create and edit sound velocity profiles.

General Description

Qimera provides a sound velocity profile (SVP) editor that allows you to edit the SVP information that is extracted from your Raw Sonar Files or from SVP data files that you've imported into your project.  The editor consists of a toolbar along the top that controls the interaction mode.  The left most panel is a list of SVP files in your project, selecting in this list updates the SVP plot in the middle of the editor.  The data from the selected profile is also shown in a text table on the right side of the editor, this allows you to modify the entries.  The date/time and position of the SVP are shown in the bottom right corner, along with the estimated sensor uncertainty.  The date/time and position (displayed in Geographic or Projected coordinates) enable spatial and time based lookup algorithms in the Processing Settings configuration dialog.  The date/time and position of SVP items are populated for the incoming file formats that support this.  For data formats that do not record this information, the position will be set to zero and the date/time will be set to January 1st, 1970.  If you make any modifications to an SVP, Qimera's Dynamic Workflow Engine will determine which raw sonar files need reprocessing and mark them accordingly in the project tree view.




Combo box

The combo box at the left side of the Toolbar allows you to choose the SVP data for a particular vessel.  Currently, the display is limited to show the SVP data from a single vessel at a time.


  Save Button

This will save any edits done to the SVP data.  Again, saving edits will trigger a reaction from the Dynamic Workflow engine.  When you save an edit to an SVP, Qimera will create a copy of the original and will display this as a set of revision versions indented below the SVP item in the list view.  Each edit session will create a new revision.  Qimera will also identify all raw sonar files that require reprocessing due to your changes.

  Revert Button

The revert button allows you to revert the currently selected SVP to its original state as it was when it was first imported into the project.  Alternately, you can right click on any revision item in the SVP list view to revert to that particular version.

  New SVP Button

The new SVP button will allow you to create a new SVP item for that currently selected vessel.  You will be presented with a dialog that will prompt you for a name and acquisition date/time.  After this step, your new SVP will appear in the SVP list window and it will be given two initial depth/velocity entries covering a depth range from 0 meters to 12,000 meters with a constant sound speed of 1500 m/s.  You can graphically add points in the SVP plot or you can edit, add or remove entries in the table view.  After creating a new SVP profile, you may need to modify the SVP Selection Strategy in the Processing Configuration Dialog.

  Explore Mode

This is the primary exploration mode of the tool.  As you move your cursor over the plot, the label in the lower left of the window will update to show the interpolated sound speed and depth of the point in the SVP that is closest to your mouse position.

  Zoom Mode

When in zoom mode, simply click and drag an area of the plot to zoom into.  Or simply single click a location to zoom in a bit on it.  Alt-click a location to zoom out a bit.  Or hit the Home button to return to the full extents of the data.  At any time, you can Shift-Click to drag the plot to a new location.  This is especially useful when you are zoomed in.

  Zoom Out Button

If you have zoomed into an area of the plot, this button will zoom out to the extents of the current set of SVPs.

  Add Entry Button

The add entry button allows you to add a depth/velocity entry graphically by clicking in the SVP plot window.  A new entry will be inserted at the appropriate location in the table view.  Once a point is added to the SVP, it cannot be moved graphically, it can only be edited manually in the table view.  It can be selected as invalid/valid just like any other point, however.

 Reject Selection

This button places the cursor in Reject Selection mode. Holding down the CTRL key will invert the mode between Reject and Accept. Use the selection style and selection area drop down buttons to modify the selection style.

 Accept Selection

This button places the cursor in Reject Selection mode. Holding down the CTRL key will invert the mode between Reject and Accept. Use the selection style and selection area drop down buttons to modify the selection style.

 Selection Style

This button changes the selection style of both the Reject and Accept buttons. Clicking this will rotate through each of the styles, or long pressing will give you a drop down menu to select the style. 

Selection Area

This button changes the selection area of both the Reject and Accept buttons. Clicking this will rotate through each of the areas, or long pressing will give you a drop down menu to select the area.

See the section on Plot Surface Editing for more information about editing with these tools.

 Undo Button

This will undo the last edit actions.  It is a pseudo-infinite undo buffer (c'mon, how much memory do you have?) in that you can make several edits in sequence and then undo those edits in the reverse sequence. 

 Redo Button

This will allow you to recover from an accidental undo operation.

 Point Size

Clicking the this icon will change the point and line size drawn in the plot area.  If you click and hold the button, it will display a menu where you can select point sizes between Small and XX-Large.  Simply clicking will cycle through all sizes.


 SVP Editor Menu

Show Column

This option allows you to change the visibility of SVP attribute columns in the table view.  Table options include:


  • Sound Speed
  • Temperature
  • Conductivity
  • Salinity
  • Pressure
  • Flags

All of these fields are stored for every sample, even if this type of data was not available during import.  At the moment, Qimera only uses the depth and sound speed values.  In the future, it will potentially use the other data types for computing sound speed and/or absorption coefficients.

Save Image

This option will allow you to save the plot to a JPEG or PNG image.

Show Grid Lines

This option will show/hide grid lines on the plot.

Tree View Context Menu

If you right click on a selection in the tree view, you will show the tree view context menu. 


This option allows you to revert to a saved revision of your plot

Uncheck Selected

This option will uncheck all SVPs in the current selection.  Check state controls visibility of the SVP in the plot.

Check Selected

This option will check all SVPs in the current selection.  Check state controls visibility of the SVP in the plot.

Check Only Selected

This option will check all SVPs in the current selection and uncheck those outside of the selection.  Check state controls visibility of the SVP in the plot.

Table Context Menu

If you right click on a row in the table, you will show the table view context menu.

Insert Before

Insert a row before the currently selected row.

Insert After

Insert a row after the currently selected row.

Display and Control

  1. SVP list view: A list view of the SVPs currently associated with the vessel chosen from the combo box in the tool bar.  Select items in this list to edit them, the chosen item will be drawn in blue in the SVP plot window.  All other items are drawn in the SVP plot in light gray in the background for context.
  2. SVP plot: Graphical plot of all SVPs from the currently selected vessel.  The currently selected SVP in the SVP list is drawn in blue, all others are drawn in gray.
  3. Table entry: A tabular list of the data points associated with the currently selected SVP.  You can manually edit them be selecting a cell.  You can also right click on any item and insert a row before/after the currently selected sample.  You can also delete/undelete a row.  Points selected for deletion in the SVP plot will be drawn in light gray and can be retrieved by right-click selection of the table entry and choosing the undelete option.
  4. SVP metadata: The time stamp and position of the SVP, as detected during import, will be displayed here.  You can view and edit the time stamp and position of the SVP, in Geographic or Projected coordinates, and save them back to the file. This will create a new version of the SVP but you can always revert to the original state by right-clicking a revision item in the SVP list and choosing the revert option.  You can set the standard deviation (SD) of the SVP measurements and you can also set the calibration bias for the depth sensor and SVP sensor as well in the event that these need to be corrected in post-processing.  The tickbox at the very bottom of the metadata section allows you to enable/disable use of the currently selected SVP item for use in processing.

Sample Editing

Editing SVP sample data can happen either by using the selection tools in the plot area or by directly modifying the table values.  Table modification can only work on a single SVP selection while plot tool based editing can occur on all currently selected SVPs.  Follow the examples in the appendix section on Qimera Plot Surface Editing to use the selection tools for editing samples in the plot area.  If you have many SVPs, use the check state of each to show/hide SVPs in order to declutter the plot.  Remember that only visible and selected SVPs react to the edit tools.  When you reject samples in your data, Qimera will interpolate across the gap.  When an SVP that has edits is selected, the deleted samples are shown as red points where they used to occur.  The before/after of a lasso selection edit is shown below.

If you change the Show Columns options of the table view to show Flags, you can also see the edit flags (Deleted, Added, Modified) for the specific entry as shown below.  On the left, you see several points that were deleted.  On the right, you see that one point was modified by editing the data in the text table, a point was added and several were deleted.

You can use the editing tools to edit more than one SVP at a time in the same way that you edit soundings in the various sounding editors.  Simply select all of your SVPs in the list view with the mouse (you can use Ctrl and Shift modifier keys for the usual multi-selection reasons) and use one of the selection tools to select the desired samples for deletion.  Below is a before/after view of this type of operations.  Notice that the table view is disabled when you have more than one SVP selected.  Also, if you have not saved and try to change your selection, Qimera will ask you to save your edits.


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