I understand that the bigger your telescope’s dish/mirror, the more information you receive and the better your image/data. But why does an array of relatively small dishes spread out over a mile (for example) get treated as having similar data collection powers as a single dish a mile across?
It’s this lazy reporting? Me misunderstanding? Some complex concept that I don’t understand?
Logically (to me) three twenty meter dishes should only collect three times the data of a single twenty meter dish. What an I missing?
In: 5
The more area your dish/lens/mirror/arbitrary aperture has the more photons you catch (visible, IR, radio, all photons) which gives you a brighter/stronger signal. This lets you see dimmer stars or pick up smaller asteroids on radar because the signal doesn’t get washed out by the sensor’s standard noise
The further apart the edges are the better you can discern fine detail and the less impacted by edge effects your final image is.
Each of the telescopes still works like a normal telescope, but if you can pipe all their data together then you can start treating them like a bigger one. What ends up mattering is the angles from the outside of your aperture to the target and by making the aperture bigger the angles get bigger and you can discern smaller details. If your aperture is too small then it doesn’t matter how bright your image is because the fuzzing from edge effects is going to mean everything is fuzzy no matter what you do.
So you’re on the right track. Three 20 meter dishes can collect 3x as many photons as 1 20 meter dish, but if spaced carefully and well measured they can give you better resolution but you’re still only going to see things that are a third as bring as your single telescope could
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