A regular radar works like an amateur photographer: it takes a series of blurry snapshots and tries to stitch them into a panorama. Details are smeared, and in a long corridor or crowd, the robot easily gets lost.

DiffRadar abandons snapshots. It sculpts a living sculpture from radio signals — a fluid field that updates with each new reflection. Map and robot position are refined together, seamlessly. In bare walls, during sharp maneuvers, and among darting objects, the machine moves smoothly, as if on a thread. And all at the speed of a video camera—70 frames per second; radio waves travel at the speed of light, so measurements are almost instantaneous — even in total darkness or thick smoke.