Comment by RedOrGreen

Yes, in a way.

Think of a single dish radio telescope as a one-pixel camera, where measuring the emission intensity at each point in the sky lets you build up a map. Typically, this is done with high resolution on the frequency axis, which is used to map Doppler shifts for spectral lines of Hydrogen, for example [1].

With a rooftop antenna, it's not likely to be a very sensitive map, though. You'll see the Sun, and its easy to see the Milky Way transit overhead, but other than that ...

[1] https://sites.google.com/site/galfahi/