Hi all, I've been looking online for a few days and can't quite find what I need, hoping somewhere here might be able to point me in the right direction.

I'm trying to build a cell phone identifier using a Raspberry Pi.
Basically I need it to ping all the cell phones in the area and send an alert when a certain MAC gets within range.
The device needs to be fairly mobile, most likely plugged into a vehicle.
Is this possible?