Hello Reader,

Welcome back to The Build Log! Last week we showed you the upgrades we made to our autonomous submarine. This week, we'll show you the actual mission we're going to be attempting with the submarine:

We want to take a picture of a crashed WWII B-17 bomber.

The wreck sits at the bottom of the Adriatic sea at around 70 meters:

Because of the depth the plane is at, diving there is very hard and requires advanced scuba diving certifications. The mission we are attempting is also very challenging, because we want to perform it fully autonomously without any input from the operator. This is difficult for a couple of reasons:

1, Finding the wreck:

The location of the wreck is only not exactly known. The sources disagree by a couple of hundred meters. That's why we'll need to perform a search pattern on the spot to make sure we'll find it. Here are all the reported locations of the wreck (sorry for AI generated image):

2. Localization error:

The shortest possible route from the shore to the wreck is around 700 meters. We want to perform the mission while sitting on the shore. So, to make sure we take a picture of the wreck, our underwater localization error must be lower than about 30 meters. And this is a huge challenge. We don't know yet if our localization system is good enough.

Below you can see how our localization performed on our best mission - the screenshot it from a surface run, so we have both the "real" GPS-measured position and the DVL-measured position.

The position error on this mission was only around 10 meters (but over a 300 meter course). It's difficult to say what will be the position error over a longer, different-looking course.

We'll let you know what test we conduct next, to have a higher probability of making it work.

Cheers,

Piotrek, CPSdrone

PS: You can access all of the previous releases of the newsletter here.