Echograms in Hydromagic

In Hydromagic, an echogram is a graph which displays measured depth versus time elapsed. When supported by your echo sounder, it is even possible to view the sonar echo envelope from the entire water column.

An echogram display is used in some real-time displays, such as the echogram for high and low frequency data, the echogram for sub-bottom data, the echogram digitizer, and the echogram export in the soundings list.

Loading the echogram Settings Dialog

To access the echogram settings window, first select the "Preferences..." item from the "Options" menu to open the preferences dialog. In the preferences dialog, select the "Miscellaneous" tab, and click the "Setup..." button in the "Echogram Settings" section, as shown below:

The echogram settings dialog

After clicking the "Setup..." button, the following dialog appears:

Setting a Custom Echogram Range

By default the range (minimum and maximum depth in graph) is detected automatically. If you want to set the range manually, for instance to zoom in on the data, uncheck the "Autodetect depth range" checkbox and use the 'Minimum Depth Value' and 'Maximum Depth Value' text boxes to view a specific range as shown in the example below:

Maximum Update Rate

With the 'Maximum Update Rate' option you can set how often the echogram display can be refreshed per second. Please note that this option is only applicable for the real-time echogram displays since the other ones will only be redrawn when they are being zoomed or when settings are changed.

When you are using a laptop or desktop computer without an advanced graphics processing unit, sometimes a high update rate can cause the computer or software to slow down a bit. In these cases, you can select a lower update rate using this setting.

Echogram Offset

This option allows you to correct the whole echogram image with a fixed offset or draft value. For instance when you need to apply a draft after the data has been recorded and no draft has been set in the sounder use this setting to apply a correction.

Echogram Filter

The minimum and maximum filter values can be used to control which return echo intensities are displayed in the echogram. You can use this filter to eliminate noise or to suppress the display of the transmit pulse.

Echogram Colors

The echogram color editor can be used to define your own color ranges to use for the echogram. Use the buttons on the right to add, remove or insert colors. You can also choose one of the many pre-defined color schemas:

• Gold (Black, Red and Yellow);
• Four (Red, Green, Yellow and Blue);
• RGB (Red, Green, Blue and Yellow);
• HSV (Rainbow Colors);
• Gray-scale (Black, Gray, and White);
• Blue (Blue and White);
• Green (Green and White);
• Red (Red and White);
• RedBlue (Red, White and Blue);
• SIMRAD (Simrad Colors);
• Unabara (Use with Unabara sub bottom profilers).