Start Range function
The Start Range function allows you to specify the start depth of the echogram. The value defines from which depth in the water column the presentation shall start. The depth value shown and selected is by default only applied to the currently selected echogram.
How to open
This function is opened from the Main menu.
Description
You use Start Range to define the minimum depth of the displayed targets. In other words, this is the depth of the "top" of the echogram. The Range setting specifies the "bottom" depth, while the Start Range setting specifies the "top" depth.
The start range you specify applies to the currently selected echogram. It is identified with a thick border. Several echogram types are available.
Tip
If you wish to apply the new start range setting to all the current echograms of the same type, select Apply to all.
To select which echogram types you wish to see in the display presentations, use the Echogram dialog box.
If you do not have a computer keyboard connected to your EK80 system, select the Keyboard button to open an on-screen keyboard. Without a keyboard, select a predefined value. Without a keyboard, use the [+] and [−] buttons to adjust the setting.
Example
Start Range in a surface-related echogram
In a surface echogram, set the Start Range value to 0 metres. This will make the echogram start from the sea surface (provided that the transducer offset has been defined).
Set Range to the current depth plus 20 metres. The echogram will now show the area from the sea surface and down to 20 metres "below"
the sea bottom. The sea bottom contour is easily detected when the depth changes.
Example
Start Range in a pelagic echogram
In a pelagic echogram, set the Start Range value to 20 meters. This will make the echogram start from 20 meters below the sea surface (provided that the transducer
offset has been defined). Set Range to 40 meters. The echogram will now show the area from 20 meters below the sea surface, and down to 60 meters below the transducer.
Provided that the depth is larger than 60 meters, the bottom contour is not shown.
Example
Start Range and Range in bottom-related echogram
In a bottom echogram, set the Start Range value to –5 metres. This will make the echogram start from 5 metres above the sea bottom. Set Range to the 5 metres plus 10 = 15 metres. The echogram will now show the area from 5 metres above the depth, and down to 10 meters
"below" the sea bottom. The sea bottom contour will appear as a flat line.
Details
Start Range
This setting controls the upper start depth for the echogram. The vertical height of the echogram is the value defined by the Range setting.
Select either side of the button to choose a value. Select the middle of the button to open it.
Apply to All
The depth value shown and selected is by default only applied to the currently selected echogram. If you wish to apply the new start range setting to all the current echograms of the same type, select Apply to all.