We're beginning to understand the mystery of our left bias on the course.  It looks like the collision on the first day may have caused more damage than we realized.  While the vehicle survived, the calibration of the instruments was affected by more than we realized. The fact that we had to go to qualification runs so quickly in the first two rounds didn't provide enough time to fully analyze the issues.

We found several errors, each small, but all in the same direction.  We believe these may have combined to cause the effects we saw on the course.  The collision twisted the instrument platform slightly, causing an error in obstacle position reporting.  It also caused a calibration error in the heading system, which is responsible for telling the lidars where they are pointed.  This causes a bias in the track of the vehicle, plus a further error in the position of the obstacles.  There was also a registration error in the navigation system. We think we've compensated for these issues as far as we can in the short time available.  But the reality is only on the course.

Our schedule today includes calibration and practice at 10:30 and our 5th qualification run at about 4pm.  We've been testing the revisions to the navigation software and the calibration results were encouraging. But they only allowed 30 minutes in the practice area, so this can't be considered a thorough test.  We think we've gotten rid of most of the calibration errors, based on what we saw on the practice course.  We've also been running tests on the changes to internal navigation, using metal buckets to cover the GPS antennas. (see photo below)
 
DARPA announced last night that 10 teams have been selected and excused from further qualification runs.  These teams all completed at least 3 of 4 runs, and 6 are second year teams.  All are multi year programs. 

When we arrived we were convinced that we were in the top 10.  Even with the damage from the collision, our performance in the first three runs had put us in the running for the second 10 rank, but our early-out in run 4, coupled with few successful gates, puts us on the bubble today. We are speculating that we will need complete and impressive run today to stay in the hunt.