TRIPLE-CORRELATION IMAGING IN OPTICAL ASTRONOMY

This chapter discusses the triple-correlation imaging in optical astronomy. The chapter discusses the high-resolution imaging methods of speckle masking (bispectrum or triple correlation processing), speckle spectroscopy, and optical long-baseline interferometry with arrays of large telescopes. The speckle spectroscopy methods have the advantage that they yield the spectrum of each resolution element of the object in addition to the high-resolution image. The additional spectral information is important for the study of the physical nature of astronomical objects. The advantage of the optical long-baseline interferometry with three or more telescopes is that, it can yield images and spectra with excellent angular resolution. Speckle masking is useful in the multi-speckle case, in experiments at visible wavelengths, and with interferometers consisting of large telescopes, such as the very large telescope (VLT) of the European Southern Observatory. © 1991, Elsevier B.V. All rights reserved.