SafekipediaGLONASS
Adapted from Wikipedia · Adventurer experience
The Global Navigation Satellite System, known as GLONASS, is a Russian system that helps people find their way just like the Global Positioning System (GPS). It was made to give an extra way to get accurate locations around the world. When devices can use both GPS and GLONASS, they work better because they have more satellites to see. This helps them give quick and exact positions, especially in places with tall buildings or near the poles.
Work on GLONASS started in the Soviet Union in 1976. The system grew with many rocket launches from 1982 until it was finished in 1995. After some problems in the late 1990s, the Russian government made improving GLONASS very important. By 2010, it covered all of Russia's territory, and in October 2011, it had enough satellites to work anywhere in the world. The satellites have been updated many times, with the newest one, GLONASS-K2, launched in 2023.
System description
GLONASS is a global navigation satellite system that helps people find their exact locations and speeds. It is used by both the military and everyday people. The satellites fly about 19,100 kilometres above Earth and take 11 hours and 16 minutes to circle the planet. This makes GLONASS useful in places far north or south.
The system uses three groups of orbits, with eight satellites in each group. To find your location, you need signals from at least four satellites.
Signal
GLONASS satellites send out two kinds of signals: one for general use and a protected signal for special users. These signals use special codes and frequencies so they can be understood even when many satellites are sending information at the same time. The system can give positions within about 5 to 10 metres and timing within 200 nanoseconds when it is working well.
Since 2008, scientists have been working on new signals using a method called CDMA. This may allow even more satellites and better accuracy in the future. These new signals are still being tested and will be used in new satellites starting in 2023.
| Satellite series | Launches | Current status | Clock error | FDMA signals | CDMA signals | Interoperability CDMA signals | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1,602 + n×0.5625 MHz | 1,246 + n×0.4375 MHz | 1,600.995 MHz | 1,248.06 MHz | 1,202.025 MHz | 1,575.42 MHz | 1,207.14 MHz | 1,176.45 MHz | ||||
| GLONASS | 1982–2005 | Out of service | 5×10−13 | L1OF, L1SF | L2SF | ||||||
| GLONASS-M | 2003–2022 | In service | 1×10−13 | L1OF, L1SF | L2OF, L2SF | - | - | L3OC ‡ | |||
| GLONASS-K | 2011– | In service | 5×10−14...1×10−13 | L1OF, L1SF | L2OF, L2SF | - | - | L3OC | |||
| GLONASS-K2 | 2023– | Testing | 5×10−15...5×10−14 | L1OF, L1SF | L2OF, L2SF | L1OC, L1SC | L2OC, L2SC | L3OC | |||
| GLONASS-V | 2025– | Design phase | L1OF, L1SF | L2OF, L2SF | L1OC, L1SC | L2OC, L2SC | L3OC, L3SVI | ||||
| GLONASS-KМ | 2030– | Research phase | L1OF, L1SF | L2OF, L2SF | L1OC, L1SC | L2OC, L2SC | L3OC, L3SVI | L1OCM | L3OCM | L5OCM | |
| "O": open signal (standard precision), "S": obfuscated signal (high precision); "F":FDMA, "С":CDMA; n=−7,−6,−5,...,6 ‡GLONASS-M spacecraft produced since 2014 include L3OC signal | |||||||||||
| Field | Size, bits | Description | ||
|---|---|---|---|---|
| Timecode | СМВ | 12 | Constant bit sequence 0101 1111 0001 (5F1h) | |
| String type | Тип | 6 | Type of the navigational message | |
| Satellite ID | j | 6 | System ID number of the satellite (1 to 63; 0 is reserved until FDMA signal switch-off) | |
| Satellite state | Гj | 1 | This satellite is: 0 – healthy, 1 – in error state | |
| Data reliability | lj | 1 | Transmitted navigational messages are: 0 – valid, 1 – unreliable | |
| Ground control callback | П1 | 4 | (Reserved for system use) | |
| Orientation mode | П2 | 1 | Satellite orientation mode is: 0 – Sun sensor control, 1 – executing predictive thrust or mode transition | |
| UTC correction | КР | 2 | On the last day of the current quarter, at 00:00 (24:00), a UTC leap second is: 0 – not expected, 1 – expected with positive value, 2 – unknown, 3 – expected with negative value | |
| Execute correction | А | 1 | After the end of the current string, UTC correction is: 0 – not expected, 1 – expected | |
| Satellite time | ОМВ | 16 | Onboard time of the day in 2-second intervals (0 to 43,199) | |
| Information | 184 | Content of the information field is defined by string type | ||
| CRC | ЦК | 16 | Cyclic redundancy code | |
| Total | 250 | |||
| Field | Size, bits | Description | |
|---|---|---|---|
| Timecode | СМВ | 20 | Constant bit sequence 0000 0100 1001 0100 1110 (0494Eh) |
| String type | Тип | 6 | Type of the navigational message |
| Satellite time | ОМВ | 15 | Onboard time of the day in 3-second intervals (0 to 28,799) |
| Satellite ID | j | 6 | The same as in L1OC signal |
| Satellite state | Гj | 1 | |
| Data reliability | lj | 1 | |
| Ground control callback | П1 | 4 | |
| Orientation mode | 222 | ||
| UTC correction | КР | 2 | |
| Execute correction | А | 1 | |
| Information | 219 | Content of the information field is defined by string type | |
| CRC | ЦК | 24 | Cyclic redundancy code |
| Total | 300 | ||
| Type | Content of the information field |
|---|---|
| 0 | (Reserved for system use) |
| 1 | Short string for the negative leap second |
| 2 | Long string for the positive leap second |
| 10, 11, 12 | Real-time information (ephemerides and time-frequency offsets). Transmitted as a packet of three strings in sequence |
| 16 | Satellite orientation parameters for the predictive thrust maneuver |
| 20 | Almanac |
| 25 | Earth rotation parameters, ionosphere models, and time scale model for the difference between UTC(SU) and TAI |
| 31, 32 | Parameters of long-term movement model |
| 50 | Cospas-Sarsat service message – L1OC signal only |
| 60 | Text message |
| Field | Size, bits | Weight of the low bit | Description | ||
|---|---|---|---|---|---|
| Orbit type | ТО | 2 | 1 | 0 – circular orbit with 19,100 km altitude | |
| Satellite number | NS | 6 | 1 | Total number of satellites transmitting CDMA signals (1 to 63) which are referenced to in the almanac | |
| Almanac age | EA | 6 | 1 | Number of full days passed since the last almanac update | |
| Current day | NA | 11 | 1 | Day number (1 to 1,461) within a four-year interval starting on 1 January of the last leap year according to Moscow decree time | |
| Signal status | PCA | 5 | 1 | Bit field encoding types of CDMA signals transmitted by the satellite. Three highest bits correspond to signals L1, L2 and L3: 0 – transmitted, 1 – not transmitted | |
| Satellite type | PCA | 3 | 1 | Satellite model and the set of transmitted CDMA signals: 0 – GLONASS-M (L3 signal), 1 – GLONASS-K1 (L3 signal), 2 – GLONASS-K1 (L2 and L3 signals), 3 – GLONASS-K2 (L1, L2 and L3 signals) | |
| Time correction | τA | 14 | 2−20 | Rough correction from onboard time scale to the GLONASS time scale (±7.8×10−3 с) | |
| Ascension | λA | 21 | 2−20 | Longitude of the satellite's first orbital node (±1 half-cycles) | |
| Ascension time | tλA | 21 | 2−5 | Time of the day when the satellite is crossing its first orbital node (0 to 44,100 s) | |
| Inclination | ΔiA | 15 | 2−20 | Adjustments to nominal inclination (64.8°) of the satellite orbit at the moment of ascension (±0.0156 half-cycles) | |
| Eccentricity | εA | 15 | 2−20 | Eccentricity of the satellite orbit at the ascension time (0 to 0.03) | |
| Perigee | ωA | 16 | 2−15 | Argument to satellite's perigee at the ascension time (±1 half-cycles) | |
| Period | ΔTA | 19 | 2−9 | Adjustments to the satellite's nominal draconic orbital period (40,544 s) at the moment of ascension (±512 s) | |
| Period change | ΔṪA | 7 | 2−14 | Speed of change of the draconic orbital period at the moment of ascension (±3.9×10−3 s/orbit) | |
| (Reserved) | L1OC: 23 | - | |||
| L3OC: 58 | |||||
Satellites
See also: List of GLONASS satellites
The main company for the GLONASS program is Joint Stock Company Information Satellite Systems Reshetnev. This company, based in Zheleznogorsk, designs all GLONASS satellites, working with other Russian groups. Another company, Production Corporation Polyot, in Omsk, builds the satellites.
Over 30 years, the satellites have improved in three generations: the original GLONASS (since 1982), GLONASS-M (since 2003), and GLONASS-K (since 2011). Each GLONASS satellite has a special code name.
First generation
The first GLONASS satellites, called Uragan, weighed about 1,250 kg and could move to different spots in space. They were improved over time.
Six of these satellites were launched in 1985–1986 with better time tools. Twelve more were launched starting in 1987, but half were lost during launch. The ones that reached space worked well.
The most of these early satellites were launched from the Baikonur Cosmodrome using special rockets.
Second generation
The second generation, GLONASS-M, started in 1990 and first launched in 2003. These satellites last longer—seven years—and weigh a bit more at 1,480 kg. They are bigger and can make more power. Fifty-two GLONASS-M satellites have been made and launched.
As of September 2017, GLONASS-M had grown to 24 satellites in space.
Third generation
GLONASS-K is a big improvement. It is lighter, weighing 750 kg, and lasts 10 years, twice as long as the old ones. It sends out more signals for better accuracy. The first GLONASS-K satellite launched on February 26, 2011.
Because they are lighter, GLONASS-K satellites can be launched in pairs from the Plesetsk Cosmodrome or six at once from the Baikonur Cosmodrome.
Ground control
Most of the GLONASS control system is in areas that were once part of the Soviet Union, with a few in Brazil and one in Nicaragua.
The GLONASS control system includes:
- a main control center
- five tracking and command centers
- two laser stations
- ten monitoring stations
Receivers
Companies that make devices using GLONASS include:
- Furuno
- JAVAD GNSS, Inc
- Septentrio
- Topcon
- C-Nav
- Magellan Navigation
- Novatel
- ComNav technology Ltd.
- Leica Geosystems
- Hemisphere GNSS
- Trimble Inc
- u-blox
Some of the latest Garmin devices also use GLONASS. Many smartphones since 2011 also include GLONASS to get a location faster, from brands like:
| Location | System control | Telemetry, Tracking and Command | Central clock | Upload stations | Laser Ranging | Monitoring and Measuring |
|---|---|---|---|---|---|---|
| Krasnoznamensk | Yes | - | - | - | - | Yes |
| Schelkovo | - | Yes | Yes | Yes | Yes | Yes |
| Komsomolsk | - | Yes | - | Yes | Yes | Yes |
| Saint Petersburg | - | Yes | - | - | - | - |
| Ussuriysk | - | Yes | - | - | - | - |
| Yeniseysk | - | Yes | - | Yes | - | Yes |
| Yakutsk | - | - | - | - | - | Yes |
| Ulan-Ude | - | - | - | - | - | Yes |
| Nurek | - | - | - | - | - | Yes |
| Vorkuta | - | - | - | - | - | Yes |
| Murmansk | - | - | - | - | - | Yes |
| Zelenchuk | - | - | - | - | - | Yes |
Status
Availability
As of 12 March 2026, the GLONASS system has enough satellites to help people find their way all around the world.
The system needs 18 satellites to work well over Russia and 24 to cover the whole world. It can reach every place on Earth.
Sometimes, the system has problems. In April 2014, it stopped working for a short time. Also in April 2014, some satellites stopped working. In February 2016, a few satellites had trouble. After fixing things and adding new satellites, the system went back to normal.
Accuracy
In 2010, GLONASS could find your location within about 4 to 7 meters, while GPS could do it within about 2 to 9 meters.
New devices can use both GLONASS and GPS together, which helps in places with tall buildings or mountains. When using both, location can be found within about 2 to 5 meters.
In 2009, plans were made to make GLONASS even better. By 2020, it was hoped to get accuracy down to about 0.6 meters or better. New satellites and ground stations were being built in many places, including Russia, the Antarctic, and other parts of the world.
| Total | 28 SC |
|---|---|
| In operation | 24 SC (GLONASS-M/K) |
| In commissioning phase | 0 SC |
| In maintenance | 0 SC |
| Under check by the Satellite Prime Contractor | 3 SC |
| Spares | 1 SC |
| In flight tests phase | 0 SC |
History
Main article: History of GLONASS
GLONASS is a Russian satellite system that helps people find their way, just like GPS. It was made to give people another way to get accurate location information, especially in places where buildings might block the GPS signal. When devices can use both GPS and GLONASS, they can find positions faster and more precisely.
Images
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