Lateral scanner

From Memory Alpha, the free Star Trek reference

The lateral scanner was a scanning component of a starship used to scan to either side of the ship.

When the USS Defiant's computer systems were rendered inoperable by a cascade virus in 2373, the lateral scanner had to be manually initialized by the bridge crew when the ship undocked from Deep Space 9. The lateral scanners were operated at 15 megahertz out to 500 kilometers during the ship's search of the Badlands for Michael Eddington. (DS9: "For the Uniform")