Multibeam target detection algorithm

The multibeam target detection algorithm and the output of the target linking algorithm work as follows. For each ping:

1. Create a new multibeam boolean ping with the same ping geometry as the Sv operand.

2. Fill this new ping with true/false values as follows:

   1. false if
      the operand's Sv value is less than the Minimum threshold setting on the Data page of the Variable properties dialog box, or
      the operand's Sv value is greater than the Maximum threshold setting on the Data page of the Variable properties dialog box, or
      the datapoint's range is greater than the maximum range defined under Bottom elimination on the Multibeam_target_detection_page of the Variable Properties dialog box, or
      
   2. otherwise true

3. Using the settings on the Target page of the Variable Properties dialog box, create a new multibeam target for each island of neighboring true values, calculating from the Sv datapoints they represent:

   1. the Target strength using the setting specified under Target strength source on the Target_page of the Variable Properties dialog box.
   2. the geometric center, which determines the minor-axis and major-axis angular position of the multibeam target.
   3. the estimated target length.
   4. the estimated target length across beams.
   5. the estimated target range extent.
   6. the estimated target perimeter length.
   7. the estimated target area.
   8. the estimated target coefficient of variation of intensity.
   9. the estimated target compactness.
   10. the estimated target thickness.

4. Create a Multibeam targets ping containing all the targets thus identified.

5. If Link target clusters is selected on the Multibeam_target_detection_page of the Variable Properties dialog box, apply the Target linking algorithm to the identified targets.

   1. otherwise go to Step 7.

6. Using the targets returned by the Target linking algorithm and the settings on the Target page of the Variable Properties dialog box, calculate from the Sv datapoints contained in the targets:

   1. the Target strength using the setting specified in under Target strength source on the Multibeam_target_detection_page of the Variable Properties dialog box.
   2. the geometric center, which determines the minor-axis and major-axis angular position of the multibeam target.
   3. the estimated target length.
   4. the estimated target length across beams.
   5. the estimated target range extent.
   6. the estimated target perimeter length.
   7. the estimated target area.
   8. the estimated target coefficient of variation of intensity.
   9. the estimated target compactness.
   10. the estimated target thickness.

7. Create a new Multibeam targets ping containing all the identified targets and discard the multibeam boolean ping.

Notes:

• Refer to the:
  • Multibeam target detection page for further information about target detection and target linking settings.
  • Target page for further information about target property settings.

See also

Multibeam target detection operator
Target properties from multibeam data
Target linking algorithm

Echoview Help file 5.1.25 for Echoview 5.1.45 Wednesday 1st  February 2012

Please report any errors or omissions to support@echoview.com.