Abstract Details

Name: Rengaswamy Sridharan
Affiliation: Indian Institute ofAstrophysics
Conference ID: ASI2017_1255
Title : Imaging with Masked Apertures: Application to Solar Imaging
Authors and Co-Authors : Vasantha Raju N
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : We explored the use of masked apertures with non-zero transfer functions in imaging solar surface features with ground based telescopes. We estimate the transfer functions of masked apertures numerically under different seeing conditions and show that, in general, they show smaller variation with seeing compared to those of filled apertures, and thus are less sensitive to the atmospheric seeing. We apply the bi-spectrum image reconstruction code, originally developed for filled aperture speckle imaging, to the simulated images of masked aperture telescopes and show that images can be reconstructed with high fidelity under typical seeing conditions. Also, we show that the contrast enhancement can be better that achieved with filled apertures provided the object contains small scale features close to the diffraction limit of the telescope. We discuss the relative merits of using such masked apertures for solar observations.