> .. there's a clear Doppler shift in the reverb. The frequency shift goes from positive to negative at the same moment that the scooter passes us, seen as the wideband wheel noise changing color.. The speed of sound at 15 °C is 340 m/s. The maximum Doppler shift here seems to be 350 Hz. Plugging all these into the equation we get 11 km/h, which sounds like a realistic speed for a scooter.. Automated speed trap in the car park..
Upcoming 2024 "AI" PCs, tablets and phones with NPUs and WiFi 7 can use machine learning and doppler reflections to infer human activity in 3-D space (proximity, movement, heart rate, gestures), via IEEE 802.11bf WiFi Sensing, https://www.technologyreview.com/2024/02/27/1088154/wifi-sen...
> Soon, thanks to better algorithms and more standardized chip designs, [WiFi] could be invisibly monitoring our day-to-day movements for all sorts of surprising—and sometimes alarming—purposes. Yes, it could track your breathing. It could monitor for falls. It may make buildings smarter, and increase energy efficiency by tracking where people are. The flip side of this, however, is that it could also be used for any number of more nefarious purposes. Someone outside your home could potentially tell when it’s vacant, or see what you are doing inside.
Doppler radar, https://en.wikipedia.org/wiki/Doppler_radar, also applies to WiFi reflections, which can be visualized, https://www.youtube.com/watch?v=g3LT_b6K0Mc.
Upcoming 2024 "AI" PCs, tablets and phones with NPUs and WiFi 7 can use machine learning and doppler reflections to infer human activity in 3-D space (proximity, movement, heart rate, gestures), via IEEE 802.11bf WiFi Sensing, https://www.technologyreview.com/2024/02/27/1088154/wifi-sen...
> Soon, thanks to better algorithms and more standardized chip designs, [WiFi] could be invisibly monitoring our day-to-day movements for all sorts of surprising—and sometimes alarming—purposes. Yes, it could track your breathing. It could monitor for falls. It may make buildings smarter, and increase energy efficiency by tracking where people are. The flip side of this, however, is that it could also be used for any number of more nefarious purposes. Someone outside your home could potentially tell when it’s vacant, or see what you are doing inside.