The Tok'ra star mapping technology that can be used to match star configurations with existing charted star system to deduce a planets location in the galaxy.
History[]
This was used by Jacob Carter after the Tok'ra memory recall device was used upon a captured Kull warrior at the SGC. The memory recall device showed the stars in the sky above the Kull warrior's planet of origin, Tartarus. Using this with the star mapping technology, Jacob found not only the warrior's planet of origin but the Stargate address as well. (SG1: "Evolution, Part 1")