External navigational interferometer
The external navigational interferometer was a navigational system. Aboard the  starships, there was a left and right system.

In 2368, after the computer systems of the  were disrupted by a energy wave from a Satarran starship, Geordi La Forge accessed the basic system directories of the Engineering Department. According to the department, the left and right external navigational interferometers were off-line. ()

Computer technology