Multiparameter Quantum Metrology: Super-Resolution Imaging in Passive Remote Sensing

We theoretically study super-resolution imaging using an n-mode interferometer in the microwave regime for satellite-based passive remote sensing. We present a comprehensive quantum mechanical analysis concerning the multiparameter estimation of temperatures on the source plane. We construct detection modes from superpositions of the incoming modes with an optimized unitary transformation. This enables the most informative measurement based on photon counting in the detection modes. Our approach saturates the quantum Cramér-Rao bound for a set of temperatures that describes the sources. In our numerical analysis, using a maximum likelihood estimator to reconstruct an image in the source plane, we attain quantum-enhanced super-resolution yielding a pixel size of 3 kilometers, surpassing that of a comparable classical interferometer by more than a factor 10.