Any other configuration of 3 or 4 pixels is most likely caused by pattern pileup (not excluding the possibility that already the 13 patterns mentioned above may suffer from pileup, e.g. if two photons hit the same pixel during one readout frame). These are not considered as recognizable patterns. See also Sects. 7.4.2 and 7.4.5 for further details on the following counter-examples:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . triple pattern . x X x . . X m x . . . X x . . . . . . . . . . . . . . x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x . . . x x . . . . . . . . . . x . . x x . . quadruple pattern . x X . . . . X x . . . X m . . x X x . . m X . . . . x . . . . . . . . . x x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
single | double | triple | quadruple | |
PAT_TYP | 1 | 2 | 3 | 4 |
PAT_IND | 0 | for 'X', for 'x' | ||
PAT_ORI | 0 | always | ||
PI | A | sum(a) for 'X', NULL for 'x' |
After the CTI and gain corrections, in the entry for the corrected amplitude, `X' will get the sum of the corrected amplitudes of all parts of the pattern, while the corrected amplitude for `x' will be “NULL”.