ROS scans at Cal Poly

During our last day at Cal Poly, we all went to the pool and took some scans.  We had the chance to try taking scans with two sonars at the same time, here are the results (vertical scans on the left, horizontal on the right) in chronological order such that each scan was in a deeper section of the pool then the last:

I attempted to normalize the horizontal scans to all face the same direction but did not come up with convincing results.  The compass on the robot was not calibrated which may have caused some of the confusion.  However we can still gather some interesting results, for example the headings during the second scan (shown below) had a standard deviation of 86 degrees which would explain the large amount of noise in the scans.  In the future scans like these can be filtered into segments for which the ROV was competely stationary.

Another issue to fix is that the range of the scans does not appear to be the full 5 meters as desired: the edges of the pool are barely visible.  The problem seems to be in some of the sampling rate settings on the sonar that we must set manually.

Finally I put together a mosaic of these scans.  However due to the range issue overlapping area was limited so mosaicing required a lot of guess work.