Application Tips and Tricks

Scan From Above

This is to illustrate the benefit of scanning from above a target. The basic idea is to get up above the bottom and angle the sonar downward slightly. The benefit is that objects projecting above the bottom cast an "acoustic shadows" behind them which tends to highlight them on the sonar image and gives an indication of their height.

This is true for any imaging sonar including side scan, mechanical scanning, and indeed also for the Insight-240 multibeam sonar.

Here is an image from SonarView showing a sunken barge. You can clearly see the shadow behind the barge. The sonar was about 15 meters above the bottom when this data was taken.

Get Familiar with the SonarView Display Controls

Best to get familiar with SonarView and particularly with the Display Controls as they can make a big difference in the image quality. You can use the SonarView on-line demo app <LINK COMING SOON> which has built-in demo files to experiment and get used to the Display Controls.

The Display Controls adjust how the sonar data is processed and displayed. These controls can be used "live" while the sonar is running as well as during the replay of saved sonar files, and even on a still image when not pinging or replaying.

• Contrast and Brightness are roughly what they seem though the names are not to be taken literally. For strong signals, like dock pilings at 30-40 meters range, a high contrast setting works best, using the brightness to control how much of the weaker signals are imaged. For weaker signals, like a wreck at 80-100 meters range, a low contrast and low brightness are best. This prevents "washing out" of detail, and lets you use the amazing human brain's ability to recognize the features of interest. Once you've found something of interest you can often improve the image by adjusting these controls.

• Integration: This controls how many consecutive pings are averaged to create the display. So at Integration = 1 there is no averaging. 10 is the default and a pretty reasonable setting. Averaging improves the image quality significantly but if there is a lot of motion it will cause some blurring and lag.

• Range Boost: This adjusts the amount of "range compensation" applied to the signal. Settings toward the left "Near" end cause nearer echoes to be emphasized (1/R scaling), whereas setting toward the right "Far" end amplify echoes at further range more (1/R^4 scaling).

• Mirror Left/Right: The Insight-240 can be mounted bracket-above or bracket-below the sonar itself. This effectively mirrors the image left to right. If the image moves in the wrong direction when you rotate the sonar, use this check box to orient the image correctly.