Image Processing Seminar by Ryan Loomis, National Radio Astronomy Observatory
Title: Astronomical radio interferometric imaging: techniques and recent advances
Astronomical observations using ground-based radio telescopes provide a unique window into some of the most interesting objects in the night sky. In particular, interferometric imaging using arrays of telescopes such as the Atacama Large Millimeter Array (ALMA) and the Event Horizon Telescope has recently yielded spectacular images of (exo-)planet formation in action and the first ever image of a black hole.
In this talk, I will briefly review and provide historical context for some of the basic techniques and principles used in radio interferometric imaging, relating these concepts to the mathematical frameworks used in other imaging fields. Building on these principles, I will then show how they are applied for pipeline image processing in a modern observatory setting such as ALMA, additionally highlighting some of the imaging challenges we currently face. Finally, I will discuss new algorithmic development in radio imaging, particularly focusing on the family of regularized maximum likelihood techniques recently utilized by the Event Horizon Telescope.