Quote Originally Posted by jlillest View Post
There's a lot of variability in sonars out there, do you have a link for the one you were using or know the specs?

Another option for this may be to run lines down either wall and survey them both. Anytime the lines cross, you'll automatically create a loop, and if it's not obvious, the lines should come back together at some point just to help the survey. In really wide passage, this option would treat the passage as if it were a room, and this is how room surveys typically work to characterize the shape of the room. The closer the line is to the walls, the easier it is to sketch in the relative location of the walls.

Some day, quality sonar units will be available and we won't have to hack together rough solutions...
You bring up a good approach, and Sheck used that system of survey for Lafayette blue, which resulted in a very accurate map