With The EA USA Farseer Optical Sensing Array, proprietary noise reduction and phase correlation and correction processing allows for extremely high resolution imaging using a distributed array of relatively low-tech sensors.
Opportunities and Challenges of Intensity Correlating Imaging:
Does not require the propagation of collected light beams to combiner units. Routing optics and beam combiners are eliminated.
Does not require nanometer level control of nor knowledge of the relative positions of the optical components.
SNR does not suffer from beam splitting and the throughput losses that plague amplitude interferometry.
ICI does not require diffraction limited optics, since the sole purpose of each telescope is to place photons onto a photo detector.
ICI is insensitive to atmospheric turbulence and therefore can be used by ground based, as well as space based facilities.
Estimating coherence magnitude from intensity cross correlations has low SNR -> Very long averaging times.*
Coherence phase must be reconstructed in order to compute the image. (very large dimension, highly nonlinear)*
*Recent advances in phase retrieval solve both problem