Distance from profile data


Is it possible to get distance readings using echosounder profile data? I conducted several experiments to compare the distance readings with the profile data, but I can’t seem to find a relation.

One of my ideas is to use the profile data to determine sloped walls and try to correct the distance readings.

Hi @abubakrazam,

That depends what you mean. Physically speaking the profile data is simply a measure of acoustic intensity that matches the frequency of a transmitted sonar pulse, which fundamentally is not a measurement of distance, so it’s not possible to get a distance reading from the profile. In practice, that acoustic intensity measurement tends to correlate reasonably well with acoustic reflections from objects hit by the sonar beam, and given a speed of sound in the transmission medium it’s possible to estimate the distance to the surface of the object that reflected the pulse. As a notable caveat, there are some materials and shapes that don’t reflect the pulse back towards the device, so not all objects can be equally well detected.

I’d recommend reading through these threads:

and then following up with any additional thoughts and questions you have afterwards :slight_smile:

Hi @EliotBR,

Thanks for your reply. I have plotted the profile data in a manner similar to the linked article. I have noticed that the maximum intensity, regardless of the distance reading is always at 2/3rds of the profile. The only difference across distances would be the width of the peaks. It seems that the peaks are wider with decreasing distance. Hence, using the profile data alone to determine distance seems difficult.

Is it correct to relate it with the distance value the SONAR provides to make sense of what it is scanning (profile data), i.e., treat both quantities as separate, and not one as a derivative of the other?