The snr is computed by normalizing the median value by the noise. The procedure continues at sequentially larger radii from the central source until the SNR falls below some threshold. The spikes are masked from the image at this radius. Persistence ghosts have not been addressed thus far in this discussion. This operation will occur before bright star processing.
Tables See the following link for a discussion of generating the look-up tables.
Bright Star Parameter Tuning . Soon, I will add the scan containing Maffei 1. The latest greatest plot of the confusion radii for bright stars is given below, as well as he spike lengths plot and the horizontal stripe plots. The confusion radii, spike lengths and horizontal stripe ratings are summarized in the following plots. Thus, for the brightest stars, these stripes are always observed, so they have a appearance rating of 1.0.