Radio-Interferometry: Improving the Resolution by a Factor of 4 (2 in each spatial dimension)
Sparse recovery allows us to reconstruct radio-interferometric images with a resolution increased by a factor two. This has been confirmed by comparing two images of the Cygnus A radio source, the first one from the LOFAR instrument and reconstructed using sparsity, and the second one from the Very Large Array at a higher frequency (and therefore with a better resolution). The contour of the VLA image in Fig 1 right matches perfectly the high resolution features that can be seen in the LOFAR color map image, while in Fig 1 left, we can see what the LOFAR pipeline produces on the same data. All small details which appear in the color image at right, but not in the left image are real, since they are also there in the contours, which corresponds to the VLA image at better resolution.
Reference: Garsden, Girard, Starck, Corbel et al, A&A, 2015
Press release 1: http://irfu.cea.fr/dap/Phocea/Vie_des_labos/Ast/ast.php?t=actu&id_ast=3548
Press release 2: French researchers push forward radio image quality in view of SKA, Thursday 10 November 2016.
Press release 3: Astrophysique et IRM, un mariage qui a du sens, May 17, 2017.