I understand that a radio telescope can be tuned to receive radio waves generated by neutral hydrogen atoms present in galactic gas, for example, within the spirals of the milky way. I think I understand that the incoming radio waves will be a mixture of red- and blue-shifted photons depending on the whether the photon sources are moving towards or away from the dish. But what about the phases of the collection of photons? Since the sources may differ in distance and time of photon release, is the signal a collection of photons in different phases? And, if so, how does the telescope take this into account in processing the data? Or perhaps the phase does not matter at all. Am I thinking about this in the right way?