Measurement iterations (Sect. 2.6). The processing block of measurements from Fig. 1 is shown at the top. It is sub-divided here in 5 algorithmic steps that are executed in iterations, until the footprint images ℱ_λ have converged, i.e. stable distributions of source footprints at each wavelength have been obtained. The deblending block itself includes iterations to disentangle contributions of many overlapping sources to the intensity of a pixel that belongs to all of them.