Question: How do very large antenna arrays synchronize with each other and why VLAs are used? – Aloka
Answer: Let me point you to a nice description of how radio telescopes and radio telescope arrays work that has been produced by the National Radio Astronomy Observatory. We connect radio telescopes together electronically so that each signal measured by each antenna is closely associated with the signals measured from every other antenna in an array. We can then use a computer to put those signals together, which allows us to make a radio picture of the object that the array antennas were looking at. We use very large arrays as they allow us to make higher spatial resolution measurements of objects. The resolution attained by a radio telescope array is proportional to the distance between its individual antenna elements. So, the farther apart we can put the antennas, the higher the resolution we have in our measurements.