About integration
Integration is one form of analysis specific to Sv data. Specifically it is the calculation of the echo integral (mean volume backscattering strength, i.e. mean Sv) over a volume defined by an analysis domain.
Other variables may also be calculated at the same time such as the Nautical Area Scattering Coefficient (NASC) and average depth of integrated data points. See Integration analysis variables or 3D_region_integration_variables for further information.
You can integrate Sv data in several ways:
- From echograms (for single beam, split beam or dual beam data)
- From scenes (for multibeam data)
- During region tracking
Note: The term "integration" is often used in Echoview for the general task of calculating Sv related analysis variables not just for calculating the "echo integral".
Integration from echograms
On-screen integration
On-screen integration reports integration results in a dialog box on the screen and marks all integrated samples with analysis-hatching. This function is only available on Sv echograms. It is possible to display integration results for selections, regions or cells.
To display on-screen integration results for a single analysis domain:
- Make a selection, point to the required cell or select a region.
- On the Shortcut (right-click) menu, click one of the following:
- Integrate Selection
- Integrate Region
- Integrate Cell
To display on-screen integration results for all visible cells:
- On the Shortcut (right-click) menu, click:
- Show cell Sv - to display mean Sv
- Show cell NASC - to display NASC
- OR -
- Press:
- I to display mean Sv
- CTRL+I to display NASC
Exported integrations
Integration results and many other metrics like supported region analysis variables, that are unavailable to on-screen analysis, can be exported to text files on the basis of regions, cells or regions by cells.
To export integration results:
- On the Echogram menu, point to Export.
- Do one of the following:
- Point to Analysis by Regions, and then click Integration.
- Point to Analysis by Cells, and then click Integration.
- Point to Analysis by Regions by Cells, and then click Integration.
See Exporting integrations from Sv echograms for more details.
See also
Integrating a selection
Integrating a region
Integrating cells
Exporting integrations
Integration from scenes
On-screen integration
On-screen integration reports integration results on the General page of the 3D Region integration results dialog box. They will only appear there if an analysis variable and algorithm are chosen on the Analysis page of the Scene Properties dialog box.
To display on-screen integration results for a single analysis domain:
- On a scene, point to the required 3D region.
- On the Shortcut (right-click) menu, click Integrate Region.
Exported integrations
Integration results for all 3D regions displayed in a scene can be exported to a text file.
To export integration results:
- On the Scene menu, point to Export
- Click Analysis by Regions
See Exporting integrations from scenes for more details.
During region tracking
Integration is required to determine the position of the center of mass for a given 3D region.
When tracking regions it is optimal to use center of mass. If not available, then geometric centers can be used.
If an analysis variable is specified during region tracking then this integration proceeds automatically.
See Detecting region tracks for further information.
See also
Exporting integrations
Essentials module
About setting variable properties
About integration algorithms