ShelfPulse — stockout and planogram-change detection

Densely packed products — cans, bottles, foils — reflect and block signal in a stable pattern. Empty the shelf and that pattern changes in one step. Normal shopping empties a shelf slowly; a sweep-theft does it all at once, and the difference between a ramp and a step is easy to see.

In the physics: Densely packed product mass (liquids, foils, metal cans) is a strong dielectric/conductive scatterer; removing it opens new propagation paths and removes reflections, shifting specific CIR tap delays and the local sigma/eps_r map. A shelf-sweep is a step change; normal shopping is a slow ramp.