Very-long-baseline Interferometry (VLBI) is a type of Radio Telescope Interferometry where the necessary timing is stored at each telescope and later analysis is used to determine the direction from which the signal came, allowing telescopes far apart to be used. It has achieved accuracies in the 10 microarcsecond range.
Some VLBI arrays:
A recent development is Electronic Very-long-baseline Interferometry, which is near-real-time transmission of the data for immediate analysis.
Event Horizon Telescope (EHT)
Electronic Very-long-baseline Interferometry (e-VLBI)
European VLBI Network (EVN)
Green Bank 140 Foot Telescope
Max Planck Institute for Radio Astronomy (MPIR)
Very-long-baseline Interferometry (VLBI)