Phase calibration for synthetic aperture imaging

High-resolution imaging can be achieved by optical aperture synthesis. Using a sparse array of smaller aperture, one can synthesize an aperture with the resolution of the equivalent filled aperture while reducing the size and weight of system. The environment and vibration factors of synthetic aperture arrays lead to errors in phase measurement and cause a severe degradation in the image quality. Real time phase calibration of synthetic aperture arrays is very important to produce images of consistently good quality. Redundant spacings calibration allows continuous calibration of the instrument with errors without requiring the model of the source.