Before revision: NAVSAT Terrestrial radio-based navigation systems; largely superseded by satellite systems LORAN— no longer in use CHAYKA, the Russian counterpart of LORAN OMEGA, Western very low frequency global-range hyperbolic radio navigation system, no longer in use Alpha, the Russian counterpart of the Omega Navigation System Celestial navigation using the periscope, or sextant—seldom used anymore due to advancement in technology Radar navigation; radar signals are easily detected so radar is normally only used in friendly waters entering and exiting ports.
After revision: NAVSAT Terrestrial radio-based navigation systems; largely superseded by satellite systems LORAN— no longer in use CHAYKA, the Russian counterpart of LORAN OMEGA, Western very low frequency global-range radio hyperbolicLow frequency radio hyperbolic navigation system, navigation system, no longer in use Alpha, the Russian counterpart of the Omega Navigation System Celestial navigation using the periscope, or sextant—seldom used anymore due to advancement in technology Radar navigation; radar signals are easily detected so radar is normally only used in friendly waters entering and exiting ports.