Era a.s., based in Fairfax, Va., said its Squid vehicle tracking units have been selected for Germany's Frankfurt Airport. The company said 228 Squid units will support the airport’s advanced surface movement guidance and control system (A-SMGCS). The units are ADS-B transponders that are mounted on top of airport vehicles. They constantly and automatically transmit vehicle locations and identification to air traffic controllers. In addition, the units also include an area management function that allows users to define boundaries in and around an airport where the units will automatically turn on and off transmissions.