The varying w spread spectrum effect for radio interferometric imaging
We study the impact of the spread spectrum effect in radio interferometry on the quality of image reconstruction. This spread spectrum effect will be induced by the wide ﬁeld-of-view of forthcoming radio interferometric telescopes. The resulting chirp modulation improves the quality of reconstructed interferometric images by increasing the incoherence of the measurement and sparsity dictionaries. We extend previous studies of this effect to consider the more realistic setting where the chirp modulation varies for each visibility measurement made by the telescope. In these ﬁrst preliminary results, we show that for this setting the quality of reconstruction improves signiﬁcantly over the case without chirp modulation and achieves almost the reconstruction quality of the case of maximal, constant chirp modulation.