Lags

Though in the images a good agreement can be observed, once we zoom into the details only a few events can be used for the analysis. In particular, I was able to extract only 14 events lasting about 25 seconds each, which correspond to changes in direction associated with the doughnuts we traced with the gator.

I extracted them, and then fitted a second order polynomial to both the video and radar record. The polynomial parameters were applied to a finer resolution temporal grid, from where I extracted the time of the maxima, and computed the difference.

In general, results are very consistent between the runs, as can be seen here:

Run #     Number of Events            Mean(lag) sec              Std Dev (lag) sec
1100                     5                                           -0.29                                    0.41
1200*                   2                                           -0.46                                    0.23
1230                     4                                           -0.25                                    0.15
1400                     3                                           -0.20                                    0.29
Overall                14                                           -0.28                                   0.28

Although 14 events (that is, about 300 seconds, 5 minutes) is hardly statistically robust, the results are in general pretty consistent, showing a small lag, less than a second.

The asterisk denotes a run where the Radar computer clock was reset using the gps. Sadly, only two events where identified in that run. Hence, at this point, we don't know if drift in the windows clock is going to be significant.