Speckle masking in astronomy: triple correlation theory and applications.

Due to the turbulent atmosphere the resolution of conventional astrophotography is limited to ≡1 sec of arc. However, the speckle-masking method can yield diffraction-limited resolution, i.e., 0.03 sec of arc with a 3.6-m telescope. Speckle masking yields true images of general astronomical objects. No point source is required in the isoplanatic field of the object. The authors present the theory of speckle masking; it makes use of triple correlations and their Fourier counterparts, the bispectra. They show algorithms for the recovery of the object from genuine astronomical bispectra data.