Piggyback on the drone is this stick-on dongle. It is a broadcast RemoteID transponder. It serves as a tag; a wireless number plate. It provides dentification and location information to help the FAA or law enforcement to track unmanned aircraft in flight.

Within the local range of a mile or so and position accuracy of 100 lateral and 150 feet vertical are designated minimum requirements for local detection.

Since the device is publicly broadcasting, anyone can receive if they are also in the area. One can download an app. Shown below is sample output from OpenDroneID OSM.

The UAS ID on the readout is the serial number of the transponder linked to the drone operator. This number is registered with the FAA. All of the rules of the road can be accessed here and LEO complaint guidelines, here.

This external ride along adds 25 grams and will induce an aerodynamic drag penalty. The alternative would be to replace the old drone with one that has UpToDate internals. $$$

UAV safety for the public.