Tohoku University, Japan is developing a new hand-held land mine detection dual-sensor (ALIS) which is equipped with a metal detector and a GPR. ALIS is equipped with a sensor tracking system, which can record the GPR and Metal detector signal with its location. The Migration processing drastically increases the quality of the imaging of the buried objects.Evaluation test of ALIS has been condu...

The placement or seeding of stream surfaces in 3D flow fields faces a number of challenges. These challenges include perception, occlusion, and the appropriate representation of flow characteristics. A variety of streamline seeding approaches exist, little corresponding work is presented for stream surfaces. We present a novel automatic stream surface seeding and filtering algorithm. Our approa...

We present an implicit method for globally computing all four classic types of integral surfaces – stream, path, streak, and time surfaces – in 3D time-dependent vector fields. Our novel formulation is based on the representation of a time surface as implicit isosurface of a 3D scalar function advected by the flow field. The evolution of a time surface is then given as an isovolume in 4D space-...

The visualization of 3D vector and tensor fields in a 2D image is challenging because the large amount of information will either be mixed during projection to 2D or lead to severe occlusion problems. In this work we segment from the symmetric 3D tensor field regions dominated by stream tubes and regions dominated by diffusion surfaces. The diffusion surfaces are integrated with a higher order ...

We present a new approach to detecting isolated closed stream lines in 2D vector fields. This approach is based on the idea of transforming the 2D vector field into an appropriate 3D vector field such that detecting closed stream lines in 2D is equivalent to intersecting certain stream surfaces in 3D. Contrary to pre-existing methods, our approach does not rely on any underlying grid structure ...

The hyporheic zone is an active ecotone between the surface stream and groundwater. Exchanges of water, nutrients, and organic matter occur in response to variations in discharge and bed topography and porosity. Upwelling subsurface water supplies stream organisms with nutrients while downwelling stream water provides dissolved oxygen and organic matter to microbes and invertebrates in the hypo...

Key words: point vortices, Riemann surfaces, Green functions. We consider N point vortices s j of strengths κ j moving on a closed (compact, boundaryless, orientable) surface S with riemannian metric g. As far as we know, only the sphere or surfaces of revolution, the latter qualitatively, have been treated in the available literature. The aim of this note is to present an intrinsic geometric f...

We describe an approach to define contours of 3D vector fields and employ them as an interactive flow visualization tool. Although contours are well-defined and commonly used for surfaces and 3D scalar fields, they have no straightforward extension in vector fields. Our approach is to extract and visualize specific stream lines which show the most similar behavior to contours on surfaces. This ...