A recent New York Times article described a Russian request to the State Department to approve U.S. locations for one or more terrestrial signal monitors for Russia’s Glonass satellite navigation system, similar to America’s GPS, suggesting the request could have worrisome consequences.
According to the article, “The CIA and other American spy agencies, as well as the Pentagon, suspect that the monitor stations would give the Russians a foothold on American territory that would sharpen the accuracy of Moscow’s satellite-steered weapons.”
Every global satellite navigation system–including GPS, Russia’s Glonass, the forthcoming Chinese BeiDou and Europe’s Galileo systems, as well as Indian and Japanese regional systems–employs terrestrial monitoring stations spread worldwide that continuously provide their controllers with the data to ensure the satellites maintain their remarkable performance.
Like ILS and all other navigation aids, the essential and primary purpose of remote monitors is to confirm system integrity, not accuracy. In fact, it’s debatable whether one or more additional monitoring stations in the U.S. would add any significant accuracy to “Moscow’s satellite-steered weapons.” And in addition to those nations’ dedicated stations, there are hundreds of navigation satellite monitors across the U.S. and overseas operated by U.S. and foreign government and civil agencies, including avionics manufacturers, industry researchers and others, with many forming part of ICAO’s International Global Navigation Satellite System Service (IGS) world network.
Moreover, since the 1990s, American and other land surveyors have used Russia’s Glonass satellite signals to improve the performance of GPS when the U.S. satellites were not in optimal orbital positions. More recently, Chinese surveyors have combined their BeiDou navigation satellite signals with those of GPS for the same reason. This is possible because ICAO decreed from the outset that every nation’s unique allocation of civil navigation satellite transmission frequencies must include at least one common international frequency. Eventually, such mix ’n’ match satellite combinations–which future-generation avionics receivers will automatically select–will bring even better worldwide navigation performance and enhanced safety to aviation and all other users.
Reportedly, the State Department has no objection to permitting Glonass monitors to be located on U.S. territory. Satellite industry observers hope that other departments will reach the same conclusion.