Hello all, In terms of Radio Astronomy, can someone please explain to me the difference between the Beam Width and the Angular Resolution? I have a 1.2m dish to play about with, and I wanted to know what it could resolve. I thought I was sorted by using the diffraction formula, but then I read about Beam Width. I found a calculator online, and when the resolution formula gave me 1.45, the Beam Width was 1.44. It seems logical to me that the FWHM of the main lobe fairly accurately describes the resoltution of a Radio Scope. If they are different, does the Beam Width differ, because it doesn't encorporate the entire beam, and the beam geometry can differ? Sorry if that sounded confusing. Thank you.