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Coherent wavelet modelling of high resolution radar imaging and clinical magnetic resonance tomography. (English) Zbl 0980.92023

Summary: Coherent wavelets form a unified basis of the multichannel perfect reconstruction analysis - synthesis filter bank of high resolution radar imaging and clinical magnetic resonance imaging (MRI). The filter bank construction is performed by the Kepplerian temperospatial Hilbert bundle strategy which allows for the stroboscopic and synchronous cross sectional quadrature filtering of phase histories in local frequency encoding channels with respect to the rotating coordinate frame of reference. The Kepplerian strategy and the associated filter bank construction take place in symplectic affine planes which are immersed as coadjoint orbits of the Heisenberg two-step nilpotent Lie group \(G\) into the foliated three-dimensional real projective space \({\mathbf P}({\mathbf R}\times \text{Lie}(G)^*)\). The Heisenberg group \(G\) acts via transvections on the line bundle defined by the projective space \({\mathbf P}({\mathbf R}\times \text{Lie}(G)^*)\). Its elliptic non-Euclidean geometry without absolute quadric, associated to the unitary dual \(\widehat{G}\) of the Heisenberg group \(G\), governs the design of the coils inside the bore of the MRI scanner, and determines the distributional reproducing kernel of the read-out process of the quantum holograms excited by the MRI scanner. Thus the pathway of this paper leads from Keppler’s approach to projective geometry to the Heisenberg approach to quantum physics.

MSC:

92C55 Biomedical imaging and signal processing
81V99 Applications of quantum theory to specific physical systems
78A45 Diffraction, scattering
22E70 Applications of Lie groups to the sciences; explicit representations