Another state of the art people counting system would be ultra wideband. It can literally count the number of heartbeats in a room. See https://m.youtube.com

Another state of the art people counting system would be ultra wideband. It can literally count the number of heartbeats in a room. See https://m.youtube.com/watch?v=adiUegDxZEs https://m.youtube.com/watch?v=adiUegDxZEs