Detection grid
From Memory Alpha, the free Star Trek reference
A detection grid was a type of sensor system used by the Xindi in the 22nd century as a method of detecting the presence of starships in the Azati Prime system. (ENT: "Azati Prime")
Another type of detection grid was used at Imperial Hall in the 24th century on Ilari. (VOY: "Warlord")
It is unclear as to whether a detection grid is similar to a tachyon detection grid, although this is unlikely as a tachyon detection grid was designed specifically to detect cloaked ships and was first used by the Federation in the 24th century.
