Adjusting the sonar range

Some echoes are close, others are further away. It is often necessary to adjust the radius of the search area. On the ST90 system, this is referred to as range.

The range setting defines from how "far" you want to detect echoes. In other words, you specify the horizontal or vertical distance from the vessel to the outer edge of the search area.

Note:

The range value selected and shown is by default only used by the active view.

Even though you can choose a high range value, that does not mean that you can detect your targets in the same range. The range value only defines the range shown in the views. Actual target detection will always depend on the operating environment, such as water temperature, salinity, interference and layers in the water column.

The selected range is divided into identical distances. These are shown as dotted circles. They are referred to as range rings.

An adjustable range ring can be added to the Horizontal and Vertical views. This ring is referred to as the variable range ring.

Procedure

  1. Click in the view you want to activate.

    The active view is identified with a thicker border. Unless you use the Apply to all function, all changes you make will only be applied to this view.

  2. Use the joystick to make the adjustment.
    Tip:

    Optionally: Turn the relevant rotary switch to make the adjustment.

    The Mk2 Operating Panel is fitted with three rotary switches. The switches are identified with numbers. Each switch can be assigned a function related to range, gain, bearing or tilt. Investigate the functionality provided on the Operating Panel page. This page is located in the Installation dialog box.

  • Optionally:

    1. Observe the Main menu.

      Its default location is on the right side of the display presentation.

    2. Select Range.
    3. Make the necessary adjustment.

      The following methods can be used to adjust this setting:

      1. Select [+] or [-] to choose the requested setting.
      2. Place the cursor on the button. Press and hold the left mouse button. Move the cursor horizontally over the button. Release the mouse button when requested value is shown.
      3. Select the middle of the button to open it. If you have a keyboard connected to the ST90 system, type the requested value.
      4. Select the middle of the button to open it. Select a value from the options provided.
    4. Open the button and select Apply to all if you wish to use the chosen setting in all the views in the current presentation mode.