I’m having a bit of an issue with a Sonoptix Echo.
I’ve noticed some subtle but clear differences in intensity between the different 30° sectors of the sonar image. It’s as if each sector has its own unique gain or contrast, (or transmission-loss normalisation, maybe?).
No matter what you do to the gain, contrast and range, or whether the BlueROV2 is moving or disarmed, the differences stay visible.
I’ve tried updating the firmware and performing a factory reset, but no changes.
It looks like the issue is specific to the 700 kHz mode. I don’t see the same behaviour when operating at 400 kHz.
I’ve attached some screenshots and examples from the raw stream. Has anyone had something similar happen with the Echo? I was wondering if this is normal behaviour when it comes to processing the individual sectors, or if it could be a sign of an issue with the sonar?
Hi @cesar.a.ortiz -
That is unusual, but could be a symptom of your environment. Are you operating inside a small tank? Does the issue persist in more open environments? Multi-path reflections in a small tank with hard walls (metal or concrete?) could be related to the image you’re seeing…
The environment is certainly a possibility. We’re currently testing in a concrete pool, which is about 33 × 11 metres and around 1 metre deep. One side is covered with gravel, and on the other there’s a large hollow metal paddle from a wave generator. So, it’s definitely not the best place to test a sonar…
That said, there are a few things that make me think there might be something else going on.The intensity discontinuities appear exactly every 30 degrees, matching the individual sectors. They also seem to affect everything; primary reflections, secondary reflections, noise, artifacts…, in the same way. The pattern remains regardless of the position or the direction of the sonar, and it not appears when using the 400 kHz mode. So, I’d say the effect is probably related to the sonar hardware or its configuration. In any case, I agree that the environment could at least be making the effect more noticeable or exacerbating it.
Unfortunately, it will probably be some time before we can test it in a more open/natural environment, so for now this pool is what we have to work with.
