Michelle Lou and Saeed Ahmed, CNN:
A global network of telescopes known as the Event Horizon Telescope project collected millions of gigabytes of data about M87 using a technique known as interferometry. However, there were still large gaps in the data that needed to be filled in.
That’s where [Katie Bouman’s] algorithm — along with several others — came in. Using imaging algorithms like Bouman’s, researchers created three scripted code pipelines to piece together the picture.
They took the “sparse and noisy data” that the telescopes spit out and tried to make an image. For the past few years, Bouman directed the verification of images and selection of imaging parameters.
It’s worth reading the 2016 press release announcing the development of this algorithm for a great explanation of how it works.