Exporting a vegetation analysis

Vegetation analysis export is available to an acoustic variable with an associated line that represents a vegetation boundary. A vegetation line may be detected by the Threshold offset operator. In Echoview, there are also other ways to create a line that represents a vegetation boundary.

Preparation

Detect a line that represents a vegetation boundary. This line will be used as the Vegetation line for the exporter.
Create or choose a line to represent the acoustic bottom or bottom of the vegetation. This line will be used as a Bottom line for the exporter.
Consider using a Minimum threshold on the Data page of the Variable Properties of the variable intended for Operand 1. Such a threshold can apply a useful constraint to a vegetation analysis.
The Export page Output settings on the EV File Properties dialog box may affect the content of the results file. An exporter object on the Dataflow window can be configured to override the Export page global settings.

Vegetation analysis export

The Vegetation analysis exporter allows you to retain and repeat a configured export analysis.

To create and configure a vegetation analysis exporter object

Open (or click to bring into focus) a supported single beam variable.
On the Echogram menu, select Export, New Analysis Exporter ...
On the New Exporter dialog box, select Vegetation analysis and click OK.
Configure the settings on the Vegetation Analysis page. The Name and notes page settings allow the customization of the export object name and a place to add text information.
The key settings for a vegetation analysis export are:
- Vegetation line
- Bottom line
- Time/ping interval
- Time between intervals
- Start interval number from the first ping
- Override the output settings specified within the EV File Properties dialog, Output empty cells
Click OK.
- OR -
On the Dataflow Toolbox, under the Exporters section, select Vegetation analysis to drag and drop it onto the Dataflow window.
Right-click the Vegetation analysis object, select Exporter Properties.
Specify Operand 1.
Configure the settings on the Vegetation Analysis page. See 'The key settings' for this type of export, in this section.
Click OK

To output an export file

Double-click the Vegetation exporter object.
Specify the file name and file path.
Click Save.

Vegetation analysis file format (*.csv)

The first row of the file records the (comma separated) names of the export data. Subsequent rows record the (comma separated) values of the export data of each vegetation analysis interval.

Variable name	Description
Process_ID	Refer to Process_ID.
Interval	Vegetation analysis interval number. The size and type of interval are specified by Time/Ping and Time between intervals (minutes). Intervals are numbered with an integer, beginning from 1 on the left side of the echogram. When working with transects, analysis interval numbers match the grid interval numbers when the Grid setting Start interval numbering from the first ping in the echogram is selected.
Ping_S	Start ping for the vegetation analysis interval.
Ping_E	End ping for the vegetation analysis interval.
Date_M	Date (yyyyMMdd) of the middle ping for the vegetation analysis interval.
Time _M	Time (HH:mm:ss.ssss) of the middle ping for the vegetation analysis interval.
Lat_M	Latitude (decimal degrees) of the middle ping for the vegetation analysis interval.
Lon_M	Longitude (decimal degrees) of the middle ping for the vegetation analysis interval.
Bottom_line_depth_mean	Mean depth (m) of the Bottom line for the vegetation analysis interval.
Bottom_line_depth_min	Minimum depth (m) of the Bottom line for the vegetation analysis interval.
Bottom_line_depth_max	Maximum depth (m) of the Bottom line for the vegetation analysis interval.
Vegetation_line_depth_mean	Mean depth (m) of Vegetation line for the vegetation analysis interval.
Vegetation_line_depth_min	Minimum depth (m) of the Vegetation line for the vegetation analysis interval.
Vegetation_line_depth_max	Maximum depth (m) of the Vegetation line for the vegetation analysis interval.
Vegetation_line_height_mean	Mean height (m) of vegetation between the Bottom and Vegetation lines of the vegetation analysis interval. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Vegetation_line_height_min	Minimum height (m) of vegetation between the Bottom and Vegetation lines of the vegetation analysis interval. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Vegetation_line_height_max	Maximum height (m) of vegetation between the Bottom and Vegetation lines of the vegetation analysis interval. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Vegetation_line_height_standDev	Standard deviation of the vegetation height (m) between the Bottom and Vegetation lines of the vegetation analysis interval. -9.9e+37 may be exported when: the Bottom line is above the Vegetation line Vegetation_line_height_standDev can't be calculated
Pings_With_Vegetation	Number of pings with vegetation for the vegetation analysis interval. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Samples_in_Domain	Number of samples included within the vegetation analysis interval. Sample midpoints must be inside the analysis domain. The sample domain is affected by Exclusion lines and specified Data page thresholds. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Samples_above_min_threshold	Number of samples above the Minimum threshold for the vegetation analysis interval. Samples_in_Domain affects the Samples_above_min_threshold. -9.9e+37 is exported when the Bottom line is above the Vegetation line.
Transect_ID	It is the integer representing the index or transect number. This variable is automatically exported if there is an assigned transect group. If no transect group is present, this column will not be present.
Transect_name	It is the unique string identifier for the transect in the transect group. This variable is automatically exported if there is an assigned transect group. If no transect group is present, this column will not be present.

Notes:

-9.9e+37 is exported for variables and 999 is exported for Lat_M and Lon_M and when there is no vegetation line.
Missing line segments in the Threshold offset line or Operand 2 line or crossed Threshold offset and Operand 2 lines are treated as no-data and will not contribute to statistical vegetation analysis calculations.
Bad data (no-data) and Bad data (empty water) samples are handled as for integration analysis export. For more information refer to About analysis domains: Analysis_regions_and_samples.
Samples with midpoints outside the domain enclosed by the vegetation line and bottom line are no longer included in the counts for Samples_in_domain and Samples_above_min_threshold. This may cause a difference in vegetation analyses output by versions prior to Echoview 15 and vegetation analysis for the same domain output by Echoview 15.