Creating single target detection variables from frequency modulated single beam data

Before you begin

The reliability of detected single targets depends on the correct configuration of calibration and transducer geometry settings for the first (and second) operand. In many cases the input operands are raw variables. When the operands are virtual variables, the rules under the inheritance of properties provide a path to the original raw variable at the start of a chain of virtual variables.


To create a single target detection virtual variable from frequency modulated pulse compressed single beam data:

  1. Open the Dataflow window.
  2. On the Shortcut (right-click) menu, click New then Variable to display the New variable dialog box.
  3. On the New Variables dialog box:
    1. In the Name box, enter a name for the single target virtual variable.
    2. In the Operator list, select Single target detection - wideband.
  4. Click OK to display the Variable Properties dialog box.
  5. On the Operands page:
    1. In the Operand 1 list, select a Complex TS pulse compressed variable.
    2. In the Operand 2 list, select the associated pulse compressed complex angular position variable.
  6. Click the Single Target Detection page.
  7. On the Single Target Detection page:
    1. In the Single target detection parameters section, enter required single target detection settings. See Single target detection page for settings information. See Single target detection - wideband algorithm page for algorithm information.
    2. In the Exclusion section, select exclusion lines (if required).
    Note: This page contains default settings to begin with. If the resulting echogram does not contain as many single targets as you expect, relax some of the constraints on this page. See Tuning single target detection algorithms for more information.
  8. Click the Filter targets page.
  9. On the Filter targets page, select the desired options (if any) and enter filter settings.
  10. Click the Data page, under the Minimum threshold section and Maximum threshold section, select the desired options (if any) and enter threshold settings.
  11. Click OK.

To display the single target virtual variable you created, on the Dataflow window, double-click the new virtual variable.

Note: You can make a selection on the Single target detection - wideband echogram and use Shortcut menu, Graph Selection, Target Frequency Response to view the frequency spectrum of the targets.

See also

About single target detection
Single target detection algorithms
Simrad and Echoview single target detection terminology
Tuning single target algorithms