The following list of concepts might be useful for a good understanding of the
content of this chapter:
•
CCD transit, the transit of a source across one single CCD.
•
FoV transit, the complete transit of a source across the focal plane, this may include one SM transit, 9 (or 8) AF CCD transits, one BP transit and one RP transit. The RVS CCD transit is irrelevant for this chapter.
•
Source catalogue, the catalogue formed by all sources observed by Gaia. This is updated at each cycle. The catalogue used in cycle N is the one generated by the MDB Integrator at the end of cycle N-1.