Why the Line Is the Wrong Place to Start
Most border systems watch the crossing: cameras on the fence, sensors on the road, a response that begins once something is already at the line. By then the decision window is a few hundred meters wide. Polus reads the signal environment on the far side, maps every emitting target in it, and returns a meter-class 3-D fix from a single sensor that does not have to move.
01Answers Before the Approach
Movement is visible while it is still forming on the far side, not when it arrives at the fence.
02One Sensor, No Baseline
The complete fix comes from one box. No second site, no baseline between receivers, no survey.
03From Open Terrain to a Crossing Point
The same sensor works a remote approach and a busy crossing, with no change of configuration.