To get a Doppler-shifted reflection you can also... move. Ground-based surface radars can work (somehow) with just no Doppler info, cataloguing, mapping fixed reflectors and very often just building ground maps. If your radar has multiple vertically and horizontally spaced receptors (eg. phased-array) or you can aim your beams, you can also somehow build a 3D map or at least map surface features/masks. This is before anything moves.