Locator beacon

"I have a signal from Doctor Jackson's locator beacon."

- Womack

Locator beacons are devices designed to tag targets for Asgard transporter beams to gain a lock. Objects can differ from a human to a target as massive as a Stargate. The small device can be easily concealed, and does not need to be activated remotely. When always transmitting the coordinates the beacon gives off a minute energy anomaly, which can easily be fooled for other things.

The Trust used locator beacons to move the Stargate to their new Al'kesh, and themselves from the surface to their ship. The SGC tagged Dr. Jackson with a locator beacon before sending him back to Tegalus with Jarrod Kane, but the beacon was found separated from his body. After this event, Subcutaeneous locator beacons became used.