The filter W(r dip ) is then applied to each of the vectors m(t) in M so that an estimate of the dipole moment at r dip is obtained. To perform localization, an estimation of the variance or strength Va^r(r dip ) of the activity as a function of location is calculated. This is the value of the cost function Tr{W T (r dip )C m W(r dip )} at the minimum, equal to Tr{[GT(rdip)Cm−1G(rdip)]−1}.
