  Incorporating wide-field considerations in interferometric imaging is of
increasing importance for next-generation radio telescopes. Compressed sensing
techniques for interferometric imaging have been extended to wide fields
recently, recovering images in the spherical coordinate space in which they
naturally live. We review these techniques, highlighting: (i) how the
effectiveness of the spread spectrum phenomenon, due to the w component
inducing an increase of measurement incoherence, is enhanced when going to wide
fields; and (ii) how sparsity is reduced by recovering images directly on the
sphere. Both of these properties act to improve the quality of reconstructed
images.
