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.

Prior to exporting a Vegetation analysis:

  1. Detect a line that represents a vegetation boundary.
  2. Create or choose a line to represent the acoustic bottom or bottom of the vegetation. This line will be used as a Bottom line setting for a Vegettion analysis exporter.
  3. Consider using a Minimum threshold on the Data page of the Variable Properties. Such a threshold can apply a useful constraint to a vegetation analysis.

Dataflow window exporter

The Vegetation analysis exporter on the Dataflow window allows you to retain and repeat a configured export analysis.

  1. The Dataflow toolbox can be used to drag and drop an exporter into the Dataflow window. Or, on the Dataflow window, right-click and on the Shortcut menu select New, Exporter.
  2. On the New Exporter dialog box select Vegetation analysis. Click OK.
  3. Use the Operand 1 list to specify an operand.
  4. On the Name and Notes page enter notes and a name.
  5. On the Vegetation analysis page specify the Vegetation settings and Output. For more detail refer to Vegetation Analysis page properties.
  6. Click OK.
  7. To export a file, double-click the exporter object and specify an output file name and 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 and 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 counted 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.

See also

Detecting a vegetation boundary