The source acceptance is based on a positive detection in at least two energy bands. However, a strong source that only appears in a single energy band may also be accepted. Such an acceptance is based on the parameter 'IMA_detSigSingle' (Note, however, that it is NOT a statistical sigma). The default value is 12 which prevents most of the spurious detections to be accepted. However, if the aim is to find the weak sources the value can be reduced to e.g. 10. Still lower values will probably cause too many spurious sources. The number of detector pixels that contribute to the sky image decreases towards the edge of the FOV. That implies on one hand that spurious sources are more likely to occur at the edge and on the other hand that sources located there will be less reliable as is reflected in the relative error of the flux determination.