A pulsar grid was a map that used data on pulsars to indicate the location of a star system.

When the NX-class starship Enterprise discovered an Axanar vessel in 2151, the Starfleet crew sent a pulsar grid to the alien ship. The grid showed the location of the Sol system. (ENT: "Fight or Flight")

Pulsar grid in V'ger databanks

Pulsar grid in V'ger databanks, copied from the Pioneer 10 plaque

While never pointed out as such, a map showing the location of Earth using this method was included on the Pioneer 10 probe, seen in Star Trek V: The Final Frontier, and the same plaque was also in the memory banks of
The Star Trek Encyclopedia (4th ed., vol. 2, p. 189) defined "pulsar grid" as a, "Star map showing the location and pulse frequency of pulsars. Because each pulsar's frequency is unique and changes at a predictable rate, a pulsar grid is a useful tool for describing a location and epoch within the galaxy."

See alsoEdit