Radar is good at ranging. So you can locate things precisely in that dimension. It’s not great at cross-range though because a beam is typically wide. SAR gets around this by essentially using the flight path or orbit of a radar sensor to synthesize a longer antenna than you’ve got. You make some assumptions that can be violated to varying degrees that may degrade the image (you need coherence over the synthetic aperture, you assume things you’re imaging don’t move, etc.)