Multi-system All-sky Spherical Harmonic Transit Interferometry

We present multi-system spherical harmonic transit interferometry, an extension to the m-mode formalism, allowing for the inclusion of multiple interferometric systems to account for missing information on the sky; alleviating the need for prior fitting and/or regression. We simulate data with two model topologies to show we can indeed recover a genuine all-sky map. Furthermore, we explain how including multiple systems affects point-spread functions (PSFs) across declination, as well as how this method helps improving spatial coverage on the sky.