1. A method for adaptive non-rigid registration of multiple measurement modes of a target body, comprising the steps of: receiving first data comprising a first plurality of measured values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a first measurement mode of a target body; receiving second data comprising a second plurality of measured values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a different second measurement mode of the target body; determining a coarse scale transformation to maximize a coarse scale similarity measure between the first data and the second data; sub-dividing the second data into a plurality of sub-regions each comprising a spatially or temporally contiguous subset of the second data; determining a plurality of fine scale transformations to maximize within the search region a fine scale similarity measure between the plurality of sub-regions and a plurality of corresponding portions of the first data, including determining an effective current displacement, for at least one fine scale transformation, by an average of displacements due to the at least one fine scale transformation at the centers of octants of the still undivided corresponding sub-region, wherein no fine scale transformation causes an effective current displacement greater than a particular threshold; and transforming the plurality of coordinate values for each measured value of the second data based on the plurality of fine scale transformations.