In article , I wrote:
If you want to see something that is off axis, you
might be able to leverage this if each antenna
is directional and blocks most energy from outside
a main lobe narrow enough that, for small N
at least, the antanna only picks up signals from
one of the aliased angles and blocks the adjacent
ones - kind of like an RF amp passband that allows
a desired frequency through and not its image
frequency.

Actually, the angular spacing increases with N,
so if the dish excludes alias images when aligned
with the overall "optical axis" then it excludes
them when aimed off axis as well.

And I am assuming s w, or the formula gives no
aliasing at all.

George