There’s a video at YouTube on the installation of Raspberry Pi based beacon detectors in a cow shed to detect the position of cows.
Beacon detectors
Beacon on a cow
Beacons can, in fact, do a lot more than just determine location. For example, it’s possible to track extra things such as temperature, humidity and unexpected movement. In the cow shed case, hall effect beacon sensors can be put on gates to alert when gates are open/closed when they shouldn’t be. The location data can be used to provide geofencing to alert when things, people or animals enter or leave specific areas.
Read more about Real-Time Locating Systems (RTLS) using beacons.