How to open
The Colour Scale dialog box is opened by right-clicking the colour scale in the Echogram view. It can also be opened from the Active menu. To activate an echogram view, click in it.
Description
When the Colour Scale dialog box opens, it offers two adjustments for each TVG setting; minimum and maximum level. The minimum level chosen is also reflected on the relevant Minimum Level button on the Main menu.
The Colour Setup dialog box allows you to choose from several colour scales to use in the ME70 echo presentations. Which colour scale to use is mainly a personal preference based on ambient light conditions, the nature of the echoes and
your own experience.
The following colour scales are available:
12 Colours |
Sonar Colours |
Smooth ES |
Grayscale |
BI500 Colours |
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The Smooth Echosounder scale is based on the standard 12-colour scale. Additional colours have been added between them to make smoother colour transitions.
Keep in mind that in the basic scale with 12 colours, each discrete colour represents a 3 dB range of echo signal strength. This implies that the next colour is selected every time the echo strength is doubled.
TipBy default you have 64 or 12 colours available to present the echoes, and a selection of palettes. The colour scale can be retrieved any time by selecting Colour Scale on the top bar. The chosen colours are shown at the bottom of the display presentation.
If you choose to use many colours, the resolution of the display presentation is greatly improved. It is then easier to distinguish the difference between the various echoes of different size and/or target strength.
Each end of the colour scale reflects a certain echo strength measured in decibels (dB), and these values can be read in the
Colour Scale information field. By means of the Colour Scale parameters you can adjust these echo strength values. This means that you can adjust the echo strength presented by each colour. The default 3 dB range in the 12 colours scale can thus be adjusted up and own to suit your preferences. When you use 64 colours, each colour can thus represent a chosen range of echo signal strength.
ExampleIf you set the minimum level to a larger negative value, the ME70 will present weaker echoes with the dark colours. If the colour span is not changed, the maximum level will be changed accordingly.
The presentation will thus become for "sensitive" while keeping the same resolution.
If you change the colour span to a larger value you will increase the echo strength area presented, but each individual colour
will present a larger area. This means the resolution will be decreased.
Your choice of colour scale has no effect on the minimum level settings. The colour scale only controls the visual presentation of the ME70 echo data.
Details
Min(imum) Level / Max(imum) Level
Set the lower and upper limits of the echo strength you wish the relevant colour scale to reflect. There is one level definition for each TVG setting.
To determine how many dB the echo strength increases for each colour, take the numerical difference between the upper and
lower limits, and divide it with the number of colours in the scale.
(Common) Colour Span
This value sets the dynamic range of the colour scale.
Apply to All Channels
Select this box to apply the current selection to all the channels on your ME70. In this context, the phrase channel is used as a common term to identify the combination of transceiver, transducer and operating frequency.
Apply to All Layers
Select this box to apply the current selection to all the depth layers you are using on the ME70. In this context, the phrase layer is used to describe the depth layers that may be defined for the ME70 echograms. Each layer is defined by its upper and lower depth limit.