The bispectrum in model-independent imaging

The goal of future optical aperture synthesis telescopes is to achieve model independent imaging of complex sky structure with the success demonstrated in very long baseline radio interferometry. Tomorrow's optical interferometers must therefore measure both the powerspectrum and the bispectrum of a source and with greater baseline coverage than has so far been achieved. In contrast to VLBI the bispectrum in optical interferometry is not as readily obtained as the powerspectrum components. Although it is clear that image reconstruction in general cannot do without the bispectrum measurements, very little intuition exists on how many and which bispectrum components in particular are most important to record. Such knowledge has implications in the design of the beam combiner and beam handling optics of future interferometers. The authors present results of image reconstruction from simulated optical interferometry data containing a fixed amount of powerspectrum but a varying selection of bispectrum components.