Most instruments for hyperspectral Earth observation rely on dispersive
image acquisition via spatial scanning. In such systems, the Earth’s
surface is scanned line by line while the satellite carrying the
instrument moves over it. The spatial and spectral resolutions of the
image acquisition are directly coupled via a slit aperture and are
thus difficult to adjust independently. Spatio-spectral scanning
systems, on the other hand, can acquire 2D, spectrally coded images
with decoupled spatial and spectral resolutions. Despite this
advantage, they have so far been given little attention in the
literature. Simple architectures using variable filters were proposed,
but come with significant caveats. As an alternative, we investigated
the use of two dispersion stages for spatio-spectral scanning. We
provide a theoretical treatment and show by basic experiments that a
double-dispersive system provides robust and flexible image
acquisition. Based on our results, we suggest a system concept for the
implementation of a demonstrator on a small satellite.