Analysis page
The settings and sections that are available on the Analysis page of the Variable Properties dialog box or the Variable Properties - Multiple Variables Selected dialog box will depend on the data type.
These include:
Exclusions
Single beam variables
The Exclusion section allows you to choose:
- samples to exclude from analysis when performing an integration or wideband frequency response calculation
- samples to be converted to no data when applying a Processed data operator
- samples to exclude from analysis export, data export, Wideband frequency response export and vegetation export
Notes:
- Click the link (in this section) Read more about samples and integration in the Help file to go to About samples and echo integration.
- Exclude above and below lines work with respect to the transducer face.
- Bottom classification ignores exclusion lines.
- Exclusion settings can be used to set values to no data in a data export.
Settings |
Description |
Exclude above |
Select a line above which the sample data is excluded from analysis, export analysis and export data. Note: This setting can be used by Echoview integram analysis and the integram detection feature. |
Exclude below |
Select a line below which the sample data is excluded from analysis, export analysis and export data. Note: This setting can be used by Echoview integram analysis and the integram detection feature. |
Multibeam variables
The Exclusions section allows you to choose:
- samples to exclude from analysis when performing an integration
- samples to be converted to no data when applying a Processed data operator
- samples to exclude from analysis export and data export
- samples to exclude from a 3D School detection and Multibeam surface detection
Note: Exclude above and below surfaces work with respect to the transducer face.
Settings |
Description |
Exclude above |
Select a surface above which the sample data is excluded from analysis, 3D School detection, multibeam surface detection, export analysis and export data, and processed data variables. You may want to view the intersection of the surface with the multibeam pings to check what will be excluded. |
Exclude below |
Select a surface below which the sample data is excluded from analysis, 3D School detection, multibeam surface detection, export analysis and export data, and processed data variables. You may want to view the intersection of the surface with the multibeam pings to check what will be excluded. |
Surface exclusion
These settings are available for multibeam variables:
Settings |
Description |
Exclude below surface additional depth offset (m) |
The Exclude below surface is offset by the specified depth. Positive values will increase the effective surface depth. Negative values will decrease the effective surface depth. |
Exclude data beyond the minimum range of the Exclude below surface |
Select this setting to exclude all samples beyond the range R, where R is the range to the nearest point (to the transducer) on the surface-ping intersection. This feature is intended to help remove the bottom echo trace sometimes visible in multibeam echograms beyond the range R (that may be an artifact introduced in the beam forming process). |
Analysis
(Integration) Analysis settings may affect integration calculations when Sv echograms contain no-data and/or bad data regions.
- OR -
(Single target) Analysis settings may affect analysis calculations when Single target echograms contain no-data and/or bad data regions.
Note: Analysis settings will affect Bottom classification and may result in a meaningless bottom classification. It is advised that Apply bad data regions and Include the volume of no-data samples are not used for variables configured for bottom classification.
For further information refer to:
The Analysis section settings include:
Settings |
Description |
Set pings with bad line status on the exclude below line to no-data |
If selected, this option will exclude from analyses those samples or single targets in pings where the line status of the exclude-below line is bad. |
If selected, Echoview applies specific bad data region sample values and sample intervals. For single target echograms, the range intervals that coincide with bad data regions are affected. Apply bad data regions is the default setting for new EV files. This setting is unsuitable for variables used for bottom classification. See also: Examples of integration cues and outcomes. |
|
Include the volume of no-data samples - OR - Include the volume of bad data (no-data) regions |
Sv echogramsIf selected, no-data samples have a sample interval. If cleared, no-data samples are treated as if they have no sample interval. In this case the setting will affect primary and downstream integration calculations and bio-estimates. For new EV files this setting is selected by default. For EV files from previous Echoview versions, the selection of Include the volume of no-data samples is matched to the state of the historic settings in the Analysis section of the Analysis page of the Variable Properties dialog box. This setting is unsuitable for variables used for bottom classification. See also Whole excluded or no-data pings removed from ping count emulation discussion. See also: Examples of integration cues and outcomes. Single targets echogramIf Include the volume of bad data (no-data) regions is selected, range intervals that coincide with bad data (no-data) regions are included in analysis calculations. If Include the volume of bad data (no-data) regions is clear, range intervals that coincide with bad data (no-data) regions are excluded in analysis calculations. |
The Background noise setting can affect specific analysis variables and the Graph ping: Sv at 1 meter value.
Setting |
Description |
Background noise at 1m (dB) |
Specify the background noise level that will be used in calculating background noise in an analysis domain. Note: You can use the Ping graph Shortcut menu Sv TVG Curve, Sv at 1 meter (dB) to visually estimate this value for a Sv echogram. See also Using a SoundSpeedProfile: Notes |
Bottom
The Bottom settings section is used to specify key Bottom classification parameters for the Sv variable. Bottom classification algorithm parameters can be modified on the Bottom Classification page of the EV File Properties dialog box. Note that Analysis settings are
unsuitable for bottom classification. For further information refer to About bottom classification.
Setting |
Description |
Bottom line |
The bottom line used for bottom classification. |
Bottom echo threshold at 1m (dB) |
The threshold that determines the end of the first bottom echo and second bottom echo. See also: Bottom classification algorithms - Extent of the first and second bottom echoes. |
Depth normalization reference depth (m) |
Reference depth used for bottom classification depth normalization. |
Frequency Distribution
The Frequency distribution section is used by single target variables.
Settings |
Description |
Minimum value |
Analysis export frequency distribution parameters for the single target variable regions. Note: These settings are different to the onscreen single target Frequency distribution graph and Graph Properties. |
Maximum value |
|
Number of bins |
Vegetation
The Vegetation section is available for an acoustic variable with an associated vegetation boundary line. The vegetation boundary line may be detected by the Threshold offset operator. Other line creation methods can also be used to create a vegetation boundary.
Note: Consider using a Minimum and/or Maximum threshold on the Data page for the analysis.
Setting |
Description |
Vegetation line |
A selected line from the Vegetation line list. The line represents a vegetation boundary. |
Bottom line |
A selected line from the Bottom line list. The line represents a bottom boundary for the vegetation. |
Time/ping interval |
Specifies the vegetation analysis interval unit:
|
Time between intervals (minutes) |
Specifies the time in minutes for the vegetation analysis interval. |
See also
About analysis domains
Variable Properties dialog box
About integration
About samples and echo integration
About no data
Thickness mean and Height mean
ABC and NASC