30 years ago I was learning about interferometry while writing the user documentation for the Westerbork Synthesis Radio Telescope. With all the news about the black hole I had to think back of that work as radio interferometry is the core technology of creating the picture. I can only imagine how complex the correlation must have been, the sheer amount of data that has been processed for it.
The WSRT user documentation is way out of date, but for historical purposes I'm attaching it here.
