# How does analog radar signals encode two dimensions?

I understand how (one of the) principle(s) of RADAR works: send a signal, record the received scattering copy off the target, and measure the elapsing time. You might need to consider Doppler effects, but let's not worry about this. But this signal only gives you a topography of a single point. How can an analog RADAR obtain a topography map (per pulse) that has finite 2D area?

I know the pulse spreads spherically as it propagates, and so is the scattering copy, but still the antenna will receive one signal -- how can it tell which is which?

EDIT: To be more specific: Suppose your radar is in an airplane and directed downwards. It sends a pulse. On ground, there are two objects -cars, for instance- separated by distance x, and each of diameter d. When the pulse reflects off the two cars and reach the RADAR, how is the x and y axis differentiated? I'd assume the antenna lump sums everything into one energy pulse, thus losing all spatial details. This should not be an issue, however, in case of one object only.

• The RADAR antenna is directional, so the signal travels in a narrow beam, instead of propagating omnidirectionally. As the antenna rotates, it emits multiple pulses. See here. I have specifically chosen an old video, so the antenna is not a phased array. Mar 30, 2015 at 4:26
• Any large part of the signal that spreads out (away from the path of travel) is not likely to return above the threshold anyway. Also, once you do start using a phased array, the beam can be made quite a lot narrower, and it can scan back and forth very quickly, yielding useful 3d information with relative precision.
– user39962
Mar 30, 2015 at 6:36
• Required reading: Most Secret War, RV Jones and Glide Path, Arthur C Clarke Mar 30, 2015 at 17:38