We present an overview of the concepts of image surface magnetometry,
and analyze various shapes of superconducting shields in the presence
of uniform background noise fields and current sources that simulate b
iomagnetic sources. We show that, for certain geometries and sizes, th
ese shields can selectively shield background noise fields as opposed
to signals of interest. We also show that clever use of these shields
can, in some cases, allow an undisturbed measurement of the signals of
interest while attenuating noise fields by as much as four orders of
magnitude.