  In large-scale spatial surveys, such as the forthcoming ESA Euclid mission,
images may be undersampled due to the optical sensors sizes. Therefore, one may
consider using a super-resolution (SR) method to recover aliased frequencies,
prior to further analysis. This is particularly relevant for point-source
images, which provide direct measurements of the instrument point-spread
function (PSF). We introduce SPRITE, SParse Recovery of InsTrumental rEsponse,
which is an SR algorithm using a sparse analysis prior. We show that such a
prior provides significant improvements over existing methods, especially on
low SNR PSFs.
