I have a question that has confused a few of us.
When refering to a radio telescope, what is the "effective area", the dish or the aperture? I thought it would be the aperture, but there is a debate. I thought the aperture lets a certain amout of signal in, and this should be the effective area. I have an example our prof gave in class, and in some cases the effective area is the aperture, and in other cases the effective area is the dish.