1mm at 1.36 km works out to about 150 milliarcsec (mas), if you're used to those units from astronomy contexts.

Letters were 8 mm.

> To demonstrate the system’s capabilities, the team created a series of 8-mm-wide targets, each made from a reflective material and imprinted with a letter.

intensity interferometer means it interferometers intensity of light.

imaging technologies you mistook for imagination technologies and their gpu inside of a sega dreamcast or iphone, ipad,...

1.36 km = 0.85 miles