Last week, the Ministry of Transport of Russia came up with an initiative to replace GPS equipment on Russian aircraft for GLONASS equipment. The initiative of the Ministry of Transport is caused by disruptions in the work of GPS, said a member of the expert council under the Government of the Russian Federation, Andrei Ionin.
"We see what is happening, just the other day there was a message that civilian aircraft in the Syrian region are experiencing problems with GPS. I think these coincidences are not accidental, such precedents have been many times. The first one - during the conflict in Yugoslavia, such events were noted during the acute phase of the conflict in Ukraine. Therefore, in order to avoid these excesses, the Ministry of Transport in advance suggests such an initiative that the planes of Russian airlines have GLONASS. And then we are not so scared as to be with GPS, "said Ionin.
Earlier on Friday, the Ministry of Transport of Russia started drafting a bill that would require Russian airlines to install GLONASS navigation satellite systems on civil aircraft of the Russian Federation that carry out commercial air transportation.
GPS really has the function of selective access: Americans can at any time leave only an encrypted signal over a certain territory, then it will be available only to military, and not civilian consumers. That is why different countries launched alternative satellite navigation systems: GLONASS from Russia, Galileo from the European Union, BeiDou from China.
It should be noted that the equipment that supports only GLONASS, the market does not exist, there are only combined receivers that support both GLONASS and GPS. Due to the combination of data from both satellite systems, a higher accuracy in determining the coordinates is achieved, and independence from the restriction of access to GPS is also ensured.
However, you can not just take and install new equipment on airplanes; Russian airlines use mostly foreign-made aircraft, leased, and these airlines do not belong. The equipment must be certified by the aircraft manufacturer, and its installation is coordinated with the lessor.
It is also worth noting that the lack of satellite navigation - at least GLONASS, even GPS - does not prevent aircraft from navigating in space. In air navigation, ground-based radio beacons are used-radio stations sending a signal on a certain frequency from a known point. The frequencies and points are indicated on the maps. Having tuned the on-board receiver with a special "circular" antenna to the desired frequency, you can understand in which direction the radio beacon is from you.
If the beacon is the simplest, non-directional (NDB, non-directional beacon), then you can learn nothing more, but by changing the direction to this beacon at a certain speed you can calculate your coordinates. A more advanced azimuth beacon (VOR, VHF Omni-directional Radio Range) also has circular antennas and so with it you can determine the magnetic bearing, that is, to understand which course you are moving relative to this beacon. The distance-measuring beacon (DME, Distance Measuring Equipment, not to be confused with Domodedovo airport), working on the principle of radar, allows you to determine the distance to it. As a rule, azimuth and rangefinder beacons (VOR / DME) are installed in pairs.
To determine the altitude, an altimeter working according to the barometer principle is used: the higher the atmospheric pressure, the lower the altitude. However, the atmospheric pressure is constantly changing at the same point, therefore at each airport the pilots correct the altimeters in accordance with the current weather report. But on the echelons, everyone exposes the conditional pressure at 29.92 KPa, so the altitude is not known exactly, but it is not necessary - the main thing is that all planes have the same display, which is achieved.
For the approach, drive beacons and the course-glide path system (ILS) are used. Also now the GLS approach system (GNSS Landing System) is being introduced. The coordinates of the aircraft in real time are determined using a satellite system - at least GPS, even GLONASS, at least Beidou or Galileo - is not important. It is important that some satellites do not suffice to provide the required accuracy of the determination of coordinates, the error of ten meters, usual for satellite systems, is already critical. Therefore, the airport installs local control-correcting stations (GBAS, Ground Based Augmentation System), transmitting an additional signal - the idea is the same as, for example, in WAAS. Since their location, unlike satellites, is constant, and the distance to landing planes is several times smaller.