National Radio Astronomy Observatory: "ALMA Gains New Capability in First Successful VLBI Observation"
"On 13 Jan 2015, a team including members of the ALMA Phasing Project, the Joint ALMA Observatory, the APEX Telescope, and the Smithsonian Astrophysical Observatory made the first VLBI observations with ALMA at a wavelength of 1.3 mm. The two telescopes were 2.08 kilometers apart, but the same technique would be applied no matter the separation between the observing sites."Credit: ALMA (NRAO/ESO/NAOJ)
"The new ALMA/APEX observation, which took place on January 13, was an essential proof-of-concept test for the planned Event Horizon Telescope (EHT), which eventually will include a global network of millimeter-wavelength telescopes."
News release by National Radio Astronomy Observatory