Objective
Biological tissue is full of oriented structure that no detector can resolve directly: collagen fibres, dentinal tubules, myocardial fibres, the alveolar walls of the lung. The directional dark-field signal carries that orientation — every pixel scatters the beam more in one direction than another — and modulation-based imaging can record it in a single exposure, on a synchrotron or on a laboratory source.
ROOTS asks how much of that information can actually be recovered, and how reliably. The field currently describes the anisotropy with a rank-2 tensor, three numbers per pixel; ROOTS builds the retrieval that goes beyond it, quantifies its stability, and validates it against direct small-angle scattering on the same samples.
The methodological programme is described on the directional dark-field page: recovering angular harmonics beyond order two, without assembling a diffusion tensor, so that crossing and multimodal microstructure can be distinguished rather than averaged away.
Outputs
Publications and released code produced under ROOTS are tagged on the publications and code and data pages.