Mean of the Gaussian is shown below as a function of phi (phi=0 for D7). Three lowest points out of 6 were taken for parabola fit in order to find the minimum. Parabola fits have been done for all available surrounding strings at once, which gives strong constraint. Opening angle between strings is calculated based on the geometry in DB, so the gap between parabola minima is constant. The red line represents the pointing direction of LED D7.
The parabola fit described above performed for all available DOMs on String 40, 49 and 50. Results are shown below.
