# 7.6.2 Properties of the input data

The input sample comprised only those sources for which per-CCD data was available in the Cycle 2 photometry provided by CU5 and which satisfied $\geq$20 $G$-FoV transits, to ensure a reliable variogram analysis. At this time of the Gaia processing, CU7 receives per-CCD time series only for sources with more than half of their FoV transits identified as ‘noisy’ according to their p-value from the 9 CCD measurements of the considered transit (the limit defining a noisy transit being p-value below 0.01).

The analysis focused on faint sources with a mean $G$ magnitude in the range 16.5–20 mag as it is in this range that a relevant and validated detection criterion can be obtained for short timescale candidates based on the variogram analysis.