angular resolution

Angular resolution in astronomy refers to a telescope's ability to distinguish fine details. It is determined by the wavelength of observation divided by the size of the instrument. While optical telescopes are limited by atmospheric effects to about one arc second, radio telescopes can achieve much higher angular resolution, even better than one milliarcsecond, by using multiple radio telescopes in an array. This technique, known as interferometry or aperture synthesis, effectively creates a much larger aperture from widely separated telescopes, allowing for the synthesis of high-resolution images of the radio sky.12