  We present the experimental implementation of simultaneous spatial multimode
demultiplexing as a distance measurement tool. We first show a simple and
intuitive derivation of the Fisher information in the presence of Poissonian
noise. We then estimate the distance between two incoherent beams in both
directions of the transverse plane, and find a perfect accordance with
theoretical prediction, given a proper calibration of the demultiplexer. We
find that, even though sensitivity is limited by the cross-talks between
channels, we can perform measurements in 2 dimensions much beyond Rayleigh
limit with a large dynamic.
