I have recently started studying array signal processing. I am struggling to understand the intuition behind ambiguity of direction using a single linear array and how it is solved using two parallel linear arrays. Can anyone please explain me?
Consider a linear array of sensors aligned in a North-South direction. This array cannot distinguish between a signal arriving from the East versus a signal arriving from the West. Either signal will arrive at all of the sensors at the same time. Now consider what happens if there are two parallel arrays designated A and B with array A to the West of array B. A signal arriving from the East will reach the sensors in array B before the sensors in array A. Similarly a signal arriving from the West will reach the sensors in array A before those in array B. Thus the directional ambiguity no longer exists.