Laboratory multistatic polarimetric 3D SAR

Abstract

With the advent of constellations of SAR satellites, and the possibility of swarms of SAR UAV's, there is increased interest in multistatic SAR image formation. This may provide advantages including allowing three-dimensional image formation free of clutter overlay; the coherent combination of bistatic SAR geometries for improved image resolution; the collection of additional scattering information, including polarimetric. The polarimetric collection may provide useful target information, such as its orientation, polarizability or number of interactions with the radar signal; distributed receivers would be more likely to capture any bright specular responses from targets in the scene, making target outlines distinct. Highlight results from multistatic polarimetric SAR experiments at the Cranfield University GBSAR laboratory are presented, illustrating the utility of the approach.

Volumetric interferometry for sparse 3D synthetic aperture radar with bistatic geometries

“…Conventional SAR interferometry is also unable to fully separate scatterers overlaid in height, which is problematic for imaging complex targets [7]. The measured data used to demonstrate the algorithm was collected at the Cranfield University Ground‐Based SAR (GBSAR) laboratory [8, 9].…”

Resolving full-wave through-wall transmission effects in multi-static synthetic aperture radar

“…In each of these numerical experiments, the obstacle comprises two joining outer walls at right angles to one-another as a surrogate for the facing corner of a building (referred to as a 'corner wall' for brevity), which is designed to mimic our previous experimental setups [1,2].…”

“…We must also collect data from multiple heights (or elevation angles) in order to gain the 3D data required [15], but it may not always be possible to carry out such a complete collection in practice. One technological solution is to use a multi-static radar configurationmultiple distributed radar transmitters and receivers operating coherently together [2,40]. A naive approach to combining this multi-static data to form a single image however may simply exacerbate the problem of artefacts and image interpretability: data collected from different source-receiver (or bi-static) pairs will have undergone different delays and multiple-scattering through the walls, and so may not coherently combine together naively with a single-scattering model.…”

Laboratory Multistatic Polarimetric Sparse Aperture 3d Sar Investigation

“…In multistatic collections, the physical meaning of these decompositions is less clear, however bistatic generalisations have been developed 15,16,17 which have been implemented for 3D imaging of building interiors 18,19 .…”

“…Future research will involve combining multiple bistatic collections, emulating a sparse multistatic collection from a multistatic SAR drone swarm or satellite constellation. Additional polarimetric decompositions are to be investigated, in particular those likely to be physically meaningful for bistatic generalisations 15,16,17,18,19 .…”