GLONASS

{{Short description|Russian global navigation satellite system}}

{{Expand Russian|topic=tech|date=October 2023}}

{{Use British English|date=June 2020}}

{{Use dmy dates|date=April 2020}}

{{Infobox navigation satellite system

| name = GLONASS

| image = Glonass logo.png|frameless

| image_caption = GLONASS logo

| image_size =

| country = {{flag|Soviet Union}}
(now {{flag|Russia}})

| type = Military, civilian

| status = Operational

| operator = Roscosmos
({{flag|Russia}})

| coverage = Global

| precision = 2.8–7.38 metres

| satellites_nominal = 24

| satellites_current = 26

| first_launch = {{start date and age|1982|10|12|df=yes}}

| last_launch = 2 March 2025

| launch_total =

| regime = 3 × MEO planes

| orbit_height = 19,130 km

| website = {{URL|https://www.glonass-iac.ru/en/|glonass-iac.ru/en}}

| orbit_period = {{Fraction|8|17}} sd, 11 hours and 16 minutes

| revisit_period = 8 sidereal days

}}

GLONASS ({{langx|ru|ГЛОНАСС|label=none}}, {{IPA|ru|ɡɫɐˈnas|IPA}}; {{langx|ru|Глобальная навигационная спутниковая система|Global'naya Navigatsionnaya Sputnikovaya Sistema|translation=Global Navigation Satellite System|links=no}}) is a Russian satellite navigation system operating as part of a radionavigation-satellite service. It provides an alternative to Global Positioning System (GPS) and is the second navigational system in operation with global coverage and of comparable precision.

Satellite navigation devices supporting both GPS and GLONASS have more satellites available, meaning positions can be fixed more quickly and accurately, especially in built-up areas where buildings may obscure the view to some satellites.{{cite journal|pmc=3355462|pmid=22666079|doi=10.3390/s120405134|volume=12|issue=4|title=Benefits of combined GPS/GLONASS with low-cost MEMS IMUs for vehicular urban navigation|year=2012|journal=Sensors|pages=5134–5158|last1=Angrisano|first1=A.|last2=Petovello|first2=M.|last3=Pugliano|first3=G.|bibcode=2012Senso..12.5134A|doi-access=free}}{{cite web|url=http://www.oxts.com/glonass-significantly-benefits-gps/|title=GLONASS significantly benefits GPS|date=15 September 2010|access-date=7 October 2017|archive-date=15 November 2017|archive-url=https://web.archive.org/web/20171115035649/http://www.oxts.com/glonass-significantly-benefits-gps/|url-status=live}}{{cite web|url=http://developer.sonymobile.com/2012/01/19/glonass-support-in-our-latest-xperia-phones/|title=Developer Tools - Sony Developer World|website=sonymobile.com|access-date=7 October 2017|archive-date=29 December 2014|archive-url=https://web.archive.org/web/20141229185429/http://developer.sonymobile.com/2012/01/19/glonass-support-in-our-latest-xperia-phones/|url-status=live}} Owing to its higher orbital inclination, GLONASS supplementation of GPS systems also improves positioning in high latitudes (near the poles).{{cite web|title=GPS, GLONASS, and More|url=http://www2.unb.ca/gge/Resources/gpsworld.june10.pdf |archive-url=https://web.archive.org/web/20180430183527/http://www2.unb.ca/gge/Resources/gpsworld.june10.pdf |archive-date=2018-04-30 |url-status=live|publisher=University of New Brunswick|quote=Figure 2 shows the PDOP improvement in percentage when comparing the GPS-only to the GPS-plus-GLONASS PDOP values. At high latitudes, that is, above 55°, the improvement is at the 30% level.}}

Development of GLONASS began in the Soviet Union in 1976. Beginning on 12 October 1982, numerous rocket launches added satellites to the system until the completion of the constellation in 1995. In 2001, after a decline in capacity during the late 1990s, the restoration of the system was made a government priority, and funding increased substantially. GLONASS is the most expensive program of Roscosmos, consuming a third of its budget in 2010.

By 2010, GLONASS had achieved full coverage of Russia's territory. In October 2011, the full orbital constellation of 24 satellites was restored, enabling full global coverage. The GLONASS satellites' designs have undergone several upgrades, with the latest version, GLONASS-K2, launched in 2023.{{cite web |last=Hendrickx |first=Bart |url=https://www.thespacereview.com/article/4502/1 |title=The secret payloads of Russia's Glonass navigation satellites |work=The Space Review |date=19 December 2022 |access-date=20 December 2022 |archive-date=20 December 2022 |archive-url=https://web.archive.org/web/20221220033222/https://www.thespacereview.com/article/4502/1 |url-status=live }}

System description

{{Comparison satellite navigation orbits}}

GLONASS is a global navigation satellite system, providing real time position and velocity determination for military and civilian users. The satellites are located in middle circular orbit at {{cvt|19100|km}} altitude with a 64.8° inclination and an orbital period of 11 hours and 16 minutes (every 17 revolutions, done in 8 sidereal days, a satellite passes over the same location{{Cite web |title=GNSS Knowledge - GLONASS - Borealis Precision - Industry Leading Representative |url=https://www.gnss.ca/gnss/1361-glonass |access-date=2023-10-30 |website=www.gnss.ca}}).{{cite web|url=http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA484380|title=The Global Navigation System GLONASS: Development and Usage in the 21st Century|publisher=34th Annual Precise Time and Time Interval (PTTI) Meeting|year=2002|access-date=21 February 2011|archive-date=1 December 2012|archive-url=https://web.archive.org/web/20121201201715/http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA484380|url-status=dead}} GLONASS's orbit makes it especially suited for usage in high latitudes (north or south), where getting a GPS signal can be problematic.{{cite book|last=Harvey|first=Brian|title=The Rebirth of the Russian Space Program|publisher=Springer|location=Germany|year=2007|edition=1st|chapter=Military programs|isbn=978-0-387-71354-0}}{{cite news|url=http://news.bbc.co.uk/2/hi/8595704.stm|title=Glonass: Has Russia's sat-nav system come of age?|work=BBC News|date=2010-04-02|first=Katia|last=Moskvitch|access-date=22 February 2011|archive-date=13 September 2012|archive-url=https://archive.today/20120913/http://news.bbc.co.uk/2/hi/8595704.stm|url-status=live}}

The constellation operates in three orbital planes, with eight evenly spaced satellites on each. A fully operational constellation with global coverage consists of 24 satellites, while 18 satellites are necessary for covering the territory of Russia. To get a position fix the receiver must be in the range of at least four satellites.

= Signal =

{{anchor|Signals}}

== FDMA ==

File:Glonass-receiver.jpg

File:GLONASS GPS Personal Radio Beacon.jpg

GLONASS satellites transmit two types of signals: open standard-precision signal L1OF/L2OF, and obfuscated high-precision signal L1SF/L2SF.

The signals use similar DSSS encoding and binary phase-shift keying (BPSK) modulation as in GPS signals. All GLONASS satellites transmit the same code as their standard-precision signal; however each transmits on a different frequency using a 15-channel frequency-division multiple access (FDMA) technique spanning either side from 1602.0 MHz, known as the L1 band. The center frequency is 1602 MHz + n × 0.5625 MHz, where n is a satellite's frequency channel number (n=−6,...,0,...,6, previously n=0,...,13). Signals are transmitted in a 38° cone, using right-hand circular polarization, at an EIRP between 25 and 27 dBW (316 to 500 watts). Note that the 24-satellite constellation is accommodated with only 15 channels by using identical frequency channels to support antipodal (opposite side of planet in orbit) satellite pairs, as these satellites are never both in view of an Earth-based user at the same time.

The L2 band signals use the same FDMA as the L1 band signals, but transmit straddling 1246 MHz with the center frequency 1246 MHz + n × 0.4375 MHz, where n spans the same range as for L1.GLONASS transmitter specs In the original GLONASS design, only obfuscated high-precision signal was broadcast in the L2 band, but starting with GLONASS-M, an additional civil reference signal L2OF is broadcast with an identical standard-precision code to the L1OF signal.

The open standard-precision signal is generated with modulo-2 addition (XOR) of 511 kbit/s pseudo-random ranging code, 50 bit/s navigation message, and an auxiliary 100 Hz meander sequence (Manchester code), all generated using a single time/frequency oscillator. The pseudo-random code is generated with a 9-stage shift register operating with a period of 1 milliseconds.

The navigational message is modulated at 50 bits per second. The superframe of the open signal is 7500 bits long and consists of 5 frames of 30 seconds, taking 150 seconds (2.5 minutes) to transmit the continuous message. Each frame is 1500 bits long and consists of 15 strings of 100 bits (2 seconds for each string), with 85 bits (1.7 seconds) for data and check-sum bits, and 15 bits (0.3 seconds) for time mark. Strings 1-4 provide immediate data for the transmitting satellite, and are repeated every frame; the data include ephemeris, clock and frequency offsets, and satellite status. Strings 5-15 provide non-immediate data (i.e. almanac) for each satellite in the constellation, with frames I-IV each describing five satellites, and frame V describing remaining four satellites.

The ephemerides are updated every 30 minutes using data from the Ground Control segment; they use Earth Centred Earth Fixed (ECEF) Cartesian coordinates in position and velocity, and include lunisolar acceleration parameters. The almanac uses modified orbital elements (Keplerian elements) and is updated daily.

The more accurate high-precision signal is available for authorized users, such as the Russian military, yet unlike the United States P(Y) code, which is modulated by an encrypting W code, the GLONASS restricted-use codes are broadcast in the clear using only security through obscurity. The details of the high-precision signal have not been disclosed. The modulation (and therefore the tracking strategy) of the data bits on the L2SF code has recently changed from unmodulated to 250 bit/s burst at random intervals. The L1SF code is modulated by the navigation data at 50 bit/s without a Manchester meander code.

The high-precision signal is broadcast in phase quadrature with the standard-precision signal, effectively sharing the same carrier wave, but with a ten-times-higher bandwidth than the open signal. The message format of the high-precision signal remains unpublished, although attempts at reverse-engineering indicate that the superframe is composed of 72 frames, each containing 5 strings of 100 bits and taking 10 seconds to transmit, with total length of 36 000 bits or 720 seconds (12 minutes) for the whole navigational message. The additional data are seemingly allocated to critical Lunisolar acceleration parameters and clock correction terms.

=== Accuracy ===

At peak efficiency, the standard-precision signal offers horizontal positioning accuracy within 5–10 metres, vertical positioning within {{cvt|15|m}}, a velocity vector measuring within {{cvt|100|mm/s}}, and timing within 200 nanoseconds, all based on measurements from four first-generation satellites simultaneously;"A Review of GLONASS" Miller, 2000 newer satellites such as GLONASS-M improve on this.

GLONASS uses a coordinate datum named "PZ-90" (Earth Parameters 1990 – Parametry Zemli 1990), in which the precise location of the North Pole is given as an average of its position from 1990 to 1995. This is in contrast to the GPS's coordinate datum, WGS 84, which uses the location of the North Pole in 1984. As of 17 September 2007, the PZ-90 datum has been updated to version PZ-90.02 which differ from WGS 84 by less than {{cvt|400|mm}} in any given direction. Since 31 December 2013, version PZ-90.11 is being broadcast, which is aligned to the International Terrestrial Reference System and Frame 2008 at epoch 2011.0 at the centimetre level, but ideally a conversion to ITRF2008 should be done.[http://www.oosa.unvienna.org/pdf/icg/2013/icg-8/wgD/D3_3_2.pdf National Reference Systems of the Russian Federation used in GLONASS.] {{Webarchive|url=https://web.archive.org/web/20140714182933/http://www.oosa.unvienna.org/pdf/icg/2013/icg-8/wgD/D3_3_2.pdf |date=14 July 2014 }} V. Vdovin and M. Vinogradova (TSNIImash), 8th ICG meeting, Dubai, November 2013{{cite web|url=http://www.glonass-iac.ru/en/content/news/?ELEMENT_ID=721|title=The transition to using the terrestrial geocentric coordinate system "Parametry Zemli 1990" (PZ-90.11) in operating the GLObal NAvigation Satellite System (GLONASS) has been implemented|website=glonass-iac.ru|access-date=2 September 2015|archive-date=7 September 2015|archive-url=https://web.archive.org/web/20150907014714/https://www.glonass-iac.ru/en/content/news/?ELEMENT_ID=721|url-status=dead}}

== CDMA ==

Since 2008, new CDMA signals are being researched for use with GLONASS.{{cite magazine|url=http://www.insidegnss.com/node/648|title=Russia Approves CDMA Signals for GLONASS, Discussing Common Signal Design|magazine=Inside GNSS|access-date=2010-12-30|archive-url=https://web.archive.org/web/20180313062644/http://www.insidegnss.com/node/648|archive-date=13 March 2018 |url-status=dead}}[http://www.navcen.uscg.gov/pdf/cgsicMeetings/47/%5B21%5D%20GLONASS%20CGSIC%20September%2024%20Fort%20Worth.pdf GLONASS Status and Progress] {{webarchive |url=https://web.archive.org/web/20110614023018/http://www.navcen.uscg.gov/pdf/cgsicMeetings/47/%5B21%5D%20GLONASS%20CGSIC%20September%2024%20Fort%20Worth.pdf|date=14 June 2011}}, S.G.Revnivykh, 47th CGSIC Meeting, 2007. "L1CR and L5R CDMA interoperable with GPS and Galileo"[http://www.unoosa.org/pdf/icg/2010/ICG5/18october/03.pdf GLONASS Status and Development] {{Webarchive|url=https://web.archive.org/web/20130921060649/http://www.unoosa.org/pdf/icg/2010/ICG5/18october/03.pdf |date=21 September 2013 }}, G.Stupak, 5th ICG Meeting[http://www.insidegnss.com/node/2487 Russia's First GLONASS-K In Orbit, CDMA Signals Coming] {{Webarchive |url=https://web.archive.org/web/20110307214035/http://www.insidegnss.com/node/2487|date=7 March 2011}} Inside GNSS (2011-02-26) Retrieved on 6 October 2011[https://www.gps.gov/cgsic/meetings/2011/revnivykh.pdf GLONASS Status and Modernization] {{Webarchive|url=https://web.archive.org/web/20191125030536/https://www.gps.gov/cgsic/meetings/2011/revnivykh.pdf |date=25 November 2019 }} Ekaterina Oleynik, Sergey Revnivykh, 51st CGSIG Meeting, September 2011[http://www.oosa.unvienna.org/pdf/icg/2011/icg-6/3.pdf GLONASS Status and Modernization] {{Webarchive|url=https://web.archive.org/web/20120515092734/http://www.oosa.unvienna.org/pdf/icg/2011/icg-6/3.pdf |date=15 May 2012 }} Sergey Revnivykh, 6th ICG Meeting, September 2011[http://www.unoosa.org/pdf/icg/2012/icg-7/3-1.pdf GLONASS Status and Modernization] {{Webarchive|url=https://web.archive.org/web/20130921060753/http://www.unoosa.org/pdf/icg/2012/icg-7/3-1.pdf |date=21 September 2013 }}, Sergey Revnivykh, 7th ICG Meeting, November 2012[http://glonass-iac.ru/aboutIAC/GLONASS_IGNSS-2013_Mirgorodskaya.pdf GLONASS Government Policy, Status and Modernization Plans] {{Webarchive|url=https://web.archive.org/web/20140102194619/http://glonass-iac.ru/aboutIAC/GLONASS_IGNSS-2013_Mirgorodskaya.pdf |date=2 January 2014 }}, Tatiana Mirgorodskaya, IGNSS-2013, 16 July 2013

The interface control documents for GLONASS CDMA signals was published in August 2016.[http://russianspacesystems.ru/bussines/navigation/glonass/interfeysnyy-kontrolnyy-dokument/ Russian Space Systems JSC - GLONASS Interface Control Documents] {{Webarchive|url=https://web.archive.org/web/20161022092226/http://russianspacesystems.ru/bussines/navigation/glonass/interfeysnyy-kontrolnyy-dokument/ |date=22 October 2016 }} (in Russian)

According to GLONASS developers, there will be three open and two restricted CDMA signals. The open signal L3OC is centered at 1202.025 MHz and uses BPSK(10) modulation for both data and pilot channels; the ranging code transmits at 10.23 million chips per second, modulated onto the carrier frequency using QPSK with in-phase data and quadrature pilot. The data is error-coded with 5-bit Barker code and the pilot with 10-bit Neuman-Hoffman code.{{cite web|url=http://gpsworld.com/glonass-modernization-12232/|title=GLONASS Modernization|publisher=GPS World|access-date=2 September 2015|date=2 November 2011|archive-url=https://web.archive.org/web/20151117032222/http://gpsworld.com/glonass-modernization-12232/|archive-date=17 November 2015|url-status=dead}}{{cite web |url=http://www.insidegnss.com/auto/julyaug11-Dumas.pdf |archive-url=https://web.archive.org/web/20140711133448/http://insidegnss.com/auto/julyaug11-Dumas.pdf |archive-date=2014-07-11 |url-status=live|title=Data|date=2011|website=insidegnss.com}}

Open L1OC and restricted L1SC signals are centered at 1600.995 MHz, and open L2OC and restricted L2SC signals are centered at 1248.06 MHz, overlapping with GLONASS FDMA signals. Open signals L1OC and L2OC use time-division multiplexing to transmit pilot and data signals, with BPSK(1) modulation for data and BOC(1,1) modulation for pilot; wide-band restricted signals L1SC and L2SC use BOC (5, 2.5) modulation for both data and pilot, transmitted in quadrature phase to the open signals; this places peak signal strength away from the center frequency of narrow-band open signals.[http://www.gpsworld.com/glonass-modernization-12232/ GLONASS Modernization] {{Webarchive|url=https://web.archive.org/web/20130921060700/http://gpsworld.com/glonass-modernization-12232/ |date=21 September 2013 }}, Yuri Urlichich, Valery Subbotin, Grigory Stupak, Vyacheslav Dvorkin, Alexander Povalyaev, Sergey Karutin, and Rudolf Bakitko, Russian Space Systems, GPS World, November 2011

Binary phase-shift keying (BPSK) is used by standard GPS and GLONASS signals. Binary offset carrier (BOC) is the modulation used by Galileo, modernized GPS, and BeiDou-2.

The navigational message of CDMA signals is transmitted as a sequence of text strings. The message has variable size - each pseudo-frame usually includes six strings and contains ephemerides for the current satellite (string types 10, 11, and 12 in a sequence) and part of the almanac for three satellites (three strings of type 20). To transmit the full almanac for all current 24 satellites, a superframe of 8 pseudo-frames is required. In the future, the superframe will be expanded to 10 pseudo-frames of data to cover full 30 satellites.

The message can also contain Earth's rotation parameters, ionosphere models, long-term orbit parameters for GLONASS satellites, and COSPAS-SARSAT messages. The system time marker is transmitted with each string; UTC leap second correction is achieved by shortening or lengthening (zero-padding) the final string of the day by one second, with abnormal strings being discarded by the receiver.[http://www.gpsworld.com/innovation-glonass-11405/ GLONASS: Developing Strategies for the Future] {{Webarchive|url=https://web.archive.org/web/20130921060741/http://gpsworld.com/innovation-glonass-11405/ |date=21 September 2013 }}, Yuri Urlichich, Valeriy Subbotin, Grigory Stupak, Vyacheslav Dvorkin, Alexander Povalyaev, and Sergey Karutin. GPS World, November 2011

The strings have a version tag to facilitate forward compatibility: future upgrades to the message format will not break older equipment, which will continue to work by ignoring new data (as long as the constellation still transmits old string types), but up-to-date equipment will be able to use additional information from newer satellites.[http://gpsworld.com/new-structure-for-glonass-nav-message/ New Structure for GLONASS Nav Message] {{Webarchive|url=https://web.archive.org/web/20131212115824/http://gpsworld.com/new-structure-for-glonass-nav-message/|date=12 December 2013}}, Alexander Povalyaev, GPS World, 2 November 2013

The navigational message of the L3OC signal is transmitted at 100 bit/s, with each string of symbols taking 3 seconds (300 bits). A pseudo-frame of 6 strings takes 18 seconds (1800 bits) to transmit. A superframe of 8 pseudo-frames is 14,400 bits long and takes 144 seconds (2 minutes 24 seconds) to transmit the full almanac.

The navigational message of the L1OC signal is transmitted at 100 bit/s. The string is 250 bits long and takes 2.5 seconds to transmit. A pseudo-frame is 1500 bits (15 seconds) long, and a superframe is 12,000 bits or 120 seconds (2 minutes).

L2OC signal does not transmit any navigational message, only the pseudo-range codes:

style="font-size: 90%;" class="wikitable"

|+ Roadmap of GLONASS modernization

! rowspan="2" | Satellite series

! rowspan="2" | Launches

! rowspan="2" | Current status

! rowspan="2" | Clock error

! colspan="2" style="background:#bfbaed;"| FDMA signals

! colspan="3" style="background:#99df99;"| CDMA signals

! colspan="3" style="background:#fefe80;"| Interoperability CDMA signals

style="background:#bfbaed;"| 1602 + n×0.5625 MHz

! style="background:#bfbaed;"| 1246 + n×0.4375 MHz

! style="background:#99df99;"| 1600.995 MHz

! style="background:#99df99;"| 1248.06 MHz

! style="background:#99df99;"| 1202.025 MHz

! style="background:#fefe80;"| 1575.42 MHz

! style="background:#fefe80;"| 1207.14 MHz

! style="background:#fefe80;"| 1176.45 MHz

style="text-align:center;"

| GLONASS

| 1982–2005

| Out of service

| 5{{e|−13}}

| L1OF, L1SF

| L2SF

|

|

|

|

|

|

style="text-align:center;"

| GLONASS-M

| 2003–2022

| In service

| 1{{e|−13}}

| L1OF, L1SF

| L2OF, L2SF

| -

| -

| L3OC

|

|

|

style="text-align:center;"

| GLONASS-K

| 2011–

| In service

| 5{{e|−14}}...1{{e

13}}

| L1OF, L1SF

| L2OF, L2SF

| -

| -

| L3OC

|

|

|

style="text-align:center;"

| GLONASS-K2

| 2023–

| Testing

| 5{{e

15}}...5{{e|−14}}

| L1OF, L1SF

| L2OF, L2SF

| L1OC, L1SC

| L2OC, L2SC

| L3OC

|

|

|

style="text-align:center;"

| GLONASS-V

| 2025–

| Design phase

|

| -

| -

| L1OC, L1SC

| L2OC, L2SC

| L3OC, L3SVI

|

|

|

style="text-align:center;"

| GLONASS-KМ

| 2030–

| Research phase

|

| L1OF, L1SF

| L2OF, L2SF

| L1OC, L1SC

| L2OC, L2SC

| L3OC, L3SVI

| L1OCM

| L3OCM

| L5OCM

colspan="12" | "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

Glonass-K1 test satellite launched in 2011 introduced L3OC signal. Glonass-M satellites produced since 2014 (s/n 755+) will also transmit L3OC signal for testing purposes.

Enhanced Glonass-K1 and Glonass-K2 satellites, to be launched from 2023, will feature a full suite of modernized CDMA signals in the existing L1 and L2 bands, which includes L1SC, L1OC, L2SC, and L2OC, as well as the L3OC signal. Glonass-K2 series should gradually replace existing satellites starting from 2023, when Glonass-M launches will cease.[http://www.unoosa.org/pdf/icg/2016/icg11/01.pdf GLONASS Program Update] {{Webarchive|url=https://web.archive.org/web/20161220060310/http://www.unoosa.org/pdf/icg/2016/icg11/01.pdf |date=20 December 2016 }}, Ivan Revnivykh, Roscosmos, 11th ICG Meeting, November 2016

Glonass-KM satellites will be launched by 2025. Additional open signals are being studied for these satellites, based on frequencies and formats used by existing GPS, Galileo, and Beidou/COMPASS signals:

  • open signal L1OCM using BOC(1,1) modulation centered at 1575.42 MHz, similar to modernized GPS signal L1C, Galileo signal E1, and Beidou/COMPASS signal B1C;
  • open signal L5OCM using BPSK(10) modulation centered at 1176.45 MHz, similar to the GPS "Safety of Life" (L5), Galileo signal E5a, and Beidou/COMPASS signal B2a;{{cite magazine|url=http://www.insidegnss.com/node/1997|title=Russia to Put 8 CDMA Signals on 4 GLONASS Frequencies|magazine=Inside GNSS|date=2010-03-17|access-date=2010-12-30|archive-url=https://web.archive.org/web/20101205054554/http://insidegnss.com/node/1997|archive-date=5 December 2010|url-status=dead}}
  • open signal L3OCM using BPSK(10) modulation centered at 1207.14 MHz, similar to Galileo signal E5b and Beidou/COMPASS signal B2b.

Such an arrangement will allow easier and cheaper implementation of multi-standard GNSS receivers.

With the introduction of CDMA signals, the constellation will be expanded to 30 active satellites by 2025; this may require eventual deprecation of FDMA signals.{{cite web |url=http://www.gpsworld.com/gnss-system/glonass/news/glonass-update-delves-constellation-details-10499|title=GLONASS Update Delves into Constellation Details|publisher=GPS World|access-date=2010-12-30|url-status=dead|archive-url=https://web.archive.org/web/20110101144902/http://www.gpsworld.com/gnss-system/glonass/news/glonass-update-delves-constellation-details-10499|archive-date=1 January 2011}} The new satellites will be deployed into three additional planes, bringing the total to six planes from the current three—aided by System for Differential Correction and Monitoring (SDCM), which is a GNSS augmentation system based on a network of ground-based control stations and communication satellites Luch 5A and Luch 5B.{{cite web |url=https://www.gpsworld.com/gnss-systemnewsglonass-modernization-maybe-six-planes-probably-more-satellites-12490/|title=GLONASS Modernization: Maybe Six Planes, Probably More Satellites|publisher=GPS World |date=10 January 2012|access-date=24 December 2018|archive-url=https://web.archive.org/web/20181102235300/http://gpsworld.com/gnss-systemnewsglonass-modernization-maybe-six-planes-probably-more-satellites-12490/|archive-date=2 November 2018|url-status=dead}}[http://www.unoosa.org/pdf/icg/2012/icg-7/3-2.pdf SDCM status and plans] {{Webarchive|url=https://web.archive.org/web/20140405044651/http://www.unoosa.org/pdf/icg/2012/icg-7/3-2.pdf |date=5 April 2014 }}, Grigory Stupak, 7th ICG Meeting, November 2012 GLONASS-KM satellites will also use new L3SVI open signal to broadcast Precise Point Positioning (PPP) to deliver GLONASS High Accuracy Services.{{cite web|url= https://home.csis.u-tokyo.ac.jp/~dinesh/GNSS_Train_files/202501/PresentationMaterials/02_GLONASS.pdf|title=GLONASS Status and Plans of Development|publisher=Roscomsos|website=ICG Programme on GNSS Applications|date=January 28, 2025|access-date=2025-04-09}}

Six additional Glonass-V satellites, using Tundra orbit in three orbital planes, will be launched starting in 2025; this regional high-orbit segment will offer increased regional availability and 25% improvement in precision over Eastern Hemisphere, similar to Japanese QZSS system and Beidou-1.{{cite web |url=https://www.gpsworld.com/directions-2019-high-orbit-glonass-and-cdma-signal/|title=Directions 2019: High-orbit GLONASS and CDMA signal|date=12 December 2018|access-date=22 December 2018|archive-url=https://web.archive.org/web/20181222173732/https://www.gpsworld.com/directions-2019-high-orbit-glonass-and-cdma-signal/|archive-date=22 December 2018|url-status=dead}} The new satellites will form two ground traces with inclination of 64.8°, eccentricity of 0.072, period of 23.9 hours, and ascending node longitude of 60° and 120°. Glonass-V vehicles are based on Glonass-K platform and will broadcast new CDMA signals only. Previously Molniya orbit, geosynchronous orbit, or inclined orbit were also under consideration for the regional segment.

Roscosmos also plans to launch up to 240 small size satellites on the low Earth orbit (LEO) to improve signal availability and interfecence; LEO satellites will have a limited lifespan of 5 years to allow a faster pace of replenishment.

= Navigational message =

== L1OC ==

class="wikitable"

|+ Full-length string for L1OC navigational message

colspan="2"| FieldSize, bitsDescription
TimecodeСМВ12Constant bit sequence 0101 1111 0001 (5F1h)
String typeТип6Type of the navigational message
Satellite IDj6System ID number of the satellite (1 to 63; 0 is reserved until FDMA signal switch-off)
Satellite stateГj1This satellite is:
0 — healthy,
1 — in error state
Data reliabilitylj1Transmitted navigational messages are:
0 — valid,
1 — unreliable
Ground control callbackП14colspan=2| (Reserved for system use)
Orientation modeП21Satellite orientation mode is:
0 — Sun sensor control,
1 — executing predictive thrust or mode transition
UTC correctionКР2On 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 correctionА1After the end of the current string, UTC correction is:
0 — not expected,
1 — expected
Satellite timeОМВ16Onboard time of the day in 2 seconds intervals (0 to 43199)
Information184Content of the information field is defined by string type
CRCЦК16Cyclic redundancy code
colspan="2"| Total250

== L3OC ==

class="wikitable"

|+ Full-length string for L3OC navigation message

colspan="2"| FieldSize, bitsDescription
TimecodeСМВ20Constant bit sequence 0000 0100 1001 0100 1110 (0494Eh)
String typeТип6Type of the navigational message
Satellite timeОМВ15Onboard time of the day in 3 seconds intervals (0 to 28799)
Satellite IDj6rowspan="7"| The same as in L1OC signal
Satellite stateГj1
Data reliabilitylj1
Ground control callbackП14
Orientation modeП2 | 222
UTC correctionКР2
Execute correctionА1
Information219Content of the information field is defined by string type
CRCЦК24Cyclic redundancy code
colspan="2"| Total300

== Common properties of open CDMA signals==

class="wikitable"

|+ String types for navigational signals

TypeContent of the information field
0(Reserved for system use)
1Short string for the negative leap second
2Long string for the positive leap second
10, 11, 12Real-time information (ephemerides and time-frequency offsets).
Transmitted as a packet of three strings in sequence
16Satellite orientation parameters for the predictive thrust maneuver
20Almanac
25Earth rotation parameters, ionosphere models, and time scale model for the difference between UTC(SU) and TAI
31, 32Parameters of long-term movement model
50Cospas-Sarsat service message — L1OC signal only
60Text message

class="wikitable"

|+ Information field of a string type 20 (almanac) for the orbit type 0.Navigational message field j (satellite ID) references the satellite for the transmitted almanac (jA)

colspan="2"| FieldSize, bitsWeight of the low bit || Description
Orbit typeТО210 — circular orbit with 19100 km altitude The set of almanac parameters depends on the orbit type. Satellites with geosynchronous, medium-Earth, and high-elliptical orbits could be employed in the future.
Satellite numberNS61Total number of satellites transmitting CDMA signals (1 to 63) which are referenced to in the almanac.
Almanac ageEA61Number of full days passed since the last almanac update.
Current dayNA111Day number (1 to 1461) within a four-year interval starting on 1 January of the last leap year In a departure from the Gregorian calendar, all years exactly divisible by 100 (i.e. 2100 and so on) are treated as leap years according to Moscow decree time.
Signal statusPCA51Bit 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 typePCA31Satellite 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 correctionτA142−20Rough correction from onboard time scale to the GLONASS time scale ({{val|±7.8e-3}} с).
AscensionλA212−20Longitude of the satellite's first orbital node (±1 half-cycles).
Ascension timetλA212−5Time of the day when the satellite is crossing its first orbital node (0 to 44100 s).
InclinationΔiA152−20Adjustments to nominal inclination (64,8°) of the satellite orbit at the moment of ascension (±0.0156 half-cycles).
EccentricityεA152−20Eccentricity of the satellite orbit at the ascension time (0 to 0.03).
PerigeeωA162−15Argument to satellite's perigee at the ascension time (±1 half-cycles).
PeriodΔTA192−9Adjustments to the satellite's nominal draconic orbital period (40544 s) at the moment of ascension (±512 s).
Period changeΔṪA72−14Speed of change of the draconic orbital period at the moment of ascension ({{val|±3.9e-3}} s/orbit).
colspan="2" rowspan="2" | (Reserved)L1OC: 23colspan="3" rowspan="2" | -
L3OC: 58

{{reflist|group=nb}}

Satellites

{{See also|List of GLONASS satellites}}

File:Glonass-K - MAKS2015part8-12.jpg

The main contractor of the GLONASS program is Joint Stock Company Information Satellite Systems Reshetnev (ISS Reshetnev, formerly called NPO-PM). The company, located in Zheleznogorsk, is the designer of all GLONASS satellites, in cooperation with the Institute for Space Device Engineering (:ru:РНИИ КП) and the Russian Institute of Radio Navigation and Time. Serial production of the satellites is accomplished by the company Production Corporation Polyot in Omsk.

Over the three decades of development, the satellite designs have gone through numerous improvements, and can be divided into three generations: the original GLONASS (since 1982), GLONASS-M (since 2003) and GLONASS-K (since 2011). Each GLONASS satellite has a GRAU designation 11F654, and each of them also has the military "Cosmos-NNNN" designation.Uragan, Russian Space Web

= First generation =

{{main|GLONASS (satellite)}}

The true first generation of GLONASS (also called Uragan) satellites were all three-axis stabilized vehicles, generally weighing {{cvt|1250|kg}} and were equipped with a modest propulsion system to permit relocation within the constellation. Over time they were upgraded to Block IIa, IIb, and IIv vehicles, with each block containing evolutionary improvements.

Six Block IIa satellites were launched in 1985–1986 with improved time and frequency standards over the prototypes, and increased frequency stability. These spacecraft also demonstrated a 16-month average operational lifetime. Block IIb spacecraft, with a two-year design lifetimes, appeared in 1987, of which a total of 12 were launched, but half were lost in launch vehicle accidents. The six spacecraft that made it to orbit worked well, operating for an average of nearly 22 months.

Block IIv was the most prolific of the first generation. Used exclusively from 1988 to 2000, and continued to be included in launches through 2005, a total of 56 satellites were launched. The design life was three years, however numerous spacecraft exceeded this, with one late model lasting 68 months, nearly double.GLONASS #787, 68.7 operational months; as reported by RSA "GLONASS constellation status" on 6 April 2007

Block II satellites were typically launched three at a time from the Baikonur Cosmodrome using Proton-K Blok-DM2 or Proton-K Briz-M boosters. The only exception was when, on two launches, an Etalon geodetic reflector satellite was substituted for a GLONASS satellite.

= Second generation =

{{main|GLONASS-M}}

The second generation of satellites, known as Glonass-M, were developed beginning in 1990 and first launched in 2003. These satellites possess a substantially increased lifetime of seven years and weigh slightly more at {{cvt|1480|kg}}. They are approximately {{cvt|2.4|m}} in diameter and {{cvt|3.7|m}} high, with a solar array span of {{cvt|7.2|m}} for an electrical power generation capability of 1600 watts at launch. The aft payload structure houses 12 primary antennas for L-band transmissions. Laser corner-cube reflectors are also carried to aid in precise orbit determination and geodetic research. On-board cesium clocks provide the local clock source. 52 Glonass-M have been produced and launched.

A total of 41 second generation satellites were launched through the end of 2013. As with the previous generation, the second generation spacecraft were launched three at a time using Proton-K Blok-DM2 or Proton-K Briz-M boosters. Some were launched alone with Soyuz-2-1b/Fregat.

In July 2015, ISS Reshetnev announced that it had completed the last GLONASS-M (No. 61) spacecraft and it was putting it in storage waiting for launch, along with eight previously built satellites.

As on 22 September 2017, GLONASS-M No.52 satellite went into operation and the orbital grouping has again increased to 24 space vehicles.{{cite news|url=https://www.geospatialworld.net/news/russia-increases-glonass-orbital-grouping-24-satellites/|title=Russia increases GLONASS orbital grouping to 24 satellites|date=2017-10-23|publisher=Geospatial World|access-date=2017-10-23|archive-date=12 July 2021|archive-url=https://web.archive.org/web/20210712015940/https://www.geospatialworld.net/news/russia-increases-glonass-orbital-grouping-24-satellites/|url-status=live}}

= Third generation =

{{main|GLONASS-K|GLONASS-K2}}

GLONASS-K is a substantial improvement of the previous generation: it is the first unpressurised GLONASS satellite with a much reduced mass of {{cvt|750|kg}} versus the {{cvt|1450|kg}} of GLONASS-M. It has an operational lifetime of 10 years, compared to the 7-year lifetime of the second generation GLONASS-M. It will transmit more navigation signals to improve the system's accuracy — including new CDMA signals in the L3 and L5 bands, which will use modulation similar to modernized GPS, Galileo, and BeiDou. Glonass-K consist of 26 satellites having satellite index 65-98 and widely used in Russian Military space.{{cite news|url=http://findarticles.com/p/articles/mi_m0BPW/is_10_21/ai_n56309362/?tag=content;col1|archive-url=https://archive.today/20120711083220/http://findarticles.com/p/articles/mi_m0BPW/is_10_21/ai_n56309362/?tag=content;col1|url-status=dead|archive-date=2012-07-11|publisher=GPS World|first=Richard |last=Langley|title=GLONASS forecast bright and plentiful|year=2010}}

The new satellite's advanced equipment—made solely from Russian components — will allow the doubling of GLONASS' accuracy.{{cite journal|url=http://www.ato.ru/content/glonass-nearing-completion|title=Glonass nearing completion|journal=Russia & CIS Observer|last=Afanasyev|first=Igor|author2=Dmitri Vorontsov |date=2010-11-26|url-status=dead|archive-url=https://web.archive.org/web/20101130065842/http://www.ato.ru/content/glonass-nearing-completion|archive-date=30 November 2010}} As with the previous satellites, these are 3-axis stabilized, nadir pointing with dual solar arrays.{{citation needed|date=December 2010}} The first GLONASS-K satellite was successfully launched on 26 February 2011.{{cite web|url=http://www.iss-reshetnev.com/images/File/magazin/2007/m2-screen_en.pdf|title=Glonass-K: a prospective satellite of the GLONASS system|publisher=Reshetnev Information Satellite Systems|year=2007|url-status=dead|archive-url=https://web.archive.org/web/20110713063606/http://www.iss-reshetnev.com/images/File/magazin/2007/m2-screen_en.pdf|archive-date=13 July 2011}}{{cite news|url=https://www.bbc.co.uk/news/world-europe-12587238|title=Russia launches satellite for global navigation system|work=BBC News|date=2011-02-26|access-date=20 June 2018|archive-date=30 November 2018|archive-url=https://web.archive.org/web/20181130234313/https://www.bbc.co.uk/news/world-europe-12587238|url-status=live}}

Due to their weight reduction, GLONASS-K spacecraft can be launched in pairs from the Plesetsk Cosmodrome launch site using the substantially lower cost Soyuz-2.1b boosters or in six-at-once from the Baikonur Cosmodrome using Proton-K Briz-M launch vehicles.

= Ground control =

File:GLONASS GroundSegment.jpg

The ground control segment of GLONASS is almost entirely located within former Soviet Union territory, except for several in Brazil and one in Nicaragua.{{cite web |url=https://newlinesmag.com/reportage/western-intelligence-fears-new-russian-sat-nav-espionage-capabilities/ |title=Western Intelligence Fears New Russian Sat-Nav's Espionage Capabilities |date=12 July 2021 |work=New Lines Magazine |first1=Holger |last1=Roonemaa |first2=Michael |last2=Weiss |access-date=19 June 2022 |archive-date=26 May 2022 |archive-url=https://web.archive.org/web/20220526011659/https://newlinesmag.com/reportage/western-intelligence-fears-new-russian-sat-nav-espionage-capabilities/ |url-status=live }}{{cite news |url=https://www.nytimes.com/2013/11/17/world/europe/a-russian-gps-using-us-soil-stirs-spy-fears.html |title=A Russian GPS Using U.S. Soil Stirs Spy Fears |date=16 November 2013 |work=The New York Times |first1=Michael |last1=Schmidt |first2=Eric |last2=Schmitt |access-date=19 June 2022 |archive-date=19 June 2022 |archive-url=https://web.archive.org/web/20220619183130/https://www.nytimes.com/2013/11/17/world/europe/a-russian-gps-using-us-soil-stirs-spy-fears.html |url-status=live }}{{cite news |url=https://www.washingtonpost.com/world/the_americas/the-soviet-union-fought-the-cold-war-in-nicaragua-now-putins-russia-is-back/2017/04/08/b43039b0-0d8b-11e7-aa57-2ca1b05c41b8_story.html |title=The Soviet Union fought the Cold War in Nicaragua. Now Putin's Russia is back. |date=8 April 2017 |newspaper=The Washington Post |last=Partlow |first=Joshua |access-date=19 June 2022 |archive-date=10 April 2022 |archive-url=https://web.archive.org/web/20220410080203/https://www.washingtonpost.com/world/the_americas/the-soviet-union-fought-the-cold-war-in-nicaragua-now-putins-russia-is-back/2017/04/08/b43039b0-0d8b-11e7-aa57-2ca1b05c41b8_story.html |url-status=live }}{{cite web |url=https://www.unav.edu/web/global-affairs/detalle/-/blogs/a-special-russian-installation-in-nicaragua |title=A 'special' Russian installation in Nicaragua |access-date=18 June 2022 |work=University of Navarra |first=Hodek |last=Jakub |archive-date=7 July 2022 |archive-url=https://web.archive.org/web/20220707003154/https://www.unav.edu/web/global-affairs/detalle/-/blogs/a-special-russian-installation-in-nicaragua |url-status=live }}

The GLONASS ground segment consists of:{{cite web|url=http://www.navipedia.net/index.php/GLONASS_Ground_Segment|title=GLONASS Ground Segment|website=navipedia.net|access-date=22 January 2017|archive-date=16 June 2017|archive-url=https://web.archive.org/web/20170616145904/http://navipedia.net/index.php/GLONASS_Ground_Segment|url-status=live}}

  • a system control centre;
  • five Telemetry, Tracking and Command centers;
  • two Laser Ranging Stations;{{cite web|url=http://cddis.gsfc.nasa.gov/lw15/docs/papers/Russian%20Laser%20Tracking%20Network.pdf |archive-url=https://web.archive.org/web/20090404085613/http://cddis.gsfc.nasa.gov/lw15/docs/papers/Russian%20Laser%20Tracking%20Network.pdf |archive-date=2009-04-04 |url-status=live|title=Russian Laser Tracking Network}} and
  • ten Monitoring and Measuring Stations.{{cite web| url = http://www.oosa.unvienna.org/pdf/publications/icg_ebook.pdf| title = Current and planned global and regional navigation satellite systems and satellite-based augmentation systems| access-date = 22 January 2017| archive-date = 2 October 2012| archive-url = https://web.archive.org/web/20121002214143/http://www.oosa.unvienna.org/pdf/publications/icg_ebook.pdf| url-status = live}}

class="wikitable plainrowheaders"
scope="col" | Locationscope="col" | System controlscope="col" | Telemetry, Tracking and Commandscope="col" | Central clockscope="col" | Upload stationsscope="col" | Laser Rangingscope="col" | Monitoring and Measuring
scope="row" | Krasnoznamensk || {{yes}} || - || - || - || - || {{yes}}
scope="row" | Schelkovo || - || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}}
scope="row" | Komsomolsk || - || {{yes}} || - || {{yes}} || {{yes}} || {{yes}}
scope="row" | Saint Petersburg || - || {{yes}} || - || - || - || -
scope="row" | Ussuriysk || - || {{yes}} || - || - || - || -
scope="row" | Yeniseysk || - || {{yes}} || - || {{yes}} || - || {{yes}}
scope="row" | Yakutsk || - || - || - || - || - || {{yes}}
scope="row" | Ulan-Ude || - || - || - || - || - || {{yes}}
scope="row" | Nurek || - || - || - || - || - || {{yes}}
scope="row" | Vorkuta || - || - || - || - || - || {{yes}}
scope="row" | Murmansk || - || - || - || - || - || {{yes}}
scope="row" | Zelenchuk || - || - || - || - || - || {{yes}}

= Receivers =

File:Stamp-russia2016-glonass.png

File:GLONASS module 1K-181.jpg

Companies producing GNSS receivers making use of GLONASS:

NPO Progress describes a receiver called GALS-A1, which combines GPS and GLONASS reception.

SkyWave Mobile Communications manufactures an Inmarsat-based satellite communications terminal that uses both GLONASS and GPS."GLONASS added to SkyWave terminals", Digital Ship, 4 December 2009, [http://www.thedigitalship.com/conferences/2006/displaynews.asp?NewsID=902 Thedigitalship.com] {{webarchive |url=https://web.archive.org/web/20110716231551/http://www.thedigitalship.com/conferences/2006/displaynews.asp?NewsID=902|date=16 July 2011}}

{{As of|2011}}, some of the latest receivers in the Garmin eTrex line also support GLONASS (along with GPS).[Garmin eTrex 20 https://buy.garmin.com/shop/shop.do?cID=145&pID=87771#overviewTab {{Webarchive|url=https://web.archive.org/web/20130309035942/https://buy.garmin.com/shop/shop.do?cID=145&pID=87771#overviewTab |date=9 March 2013 }}] Garmin also produce a standalone Bluetooth receiver, the GLO for Aviation, which combines GPS, WAAS and GLONASS.[https://buy.garmin.com/en-US/US/in-the-air/portable-gps/glo-for-aviation/prod109826.html GLO for Aviation|Garmin] {{Webarchive|url=https://web.archive.org/web/20130921062957/https://buy.garmin.com/en-US/US/in-the-air/portable-gps/glo-for-aviation/prod109826.html |date=21 September 2013 }}, buy.garmin.com, Retrieved on 2 August 2013

Various smartphones from 2011 onwards have integrated GLONASS capability in addition to their pre-existing GPS receivers, with the intention of reducing signal acquisition periods by allowing the device to pick up more satellites than with a single-network receiver, including devices from:

  • Xiaomi
  • Sony Ericsson{{cite web|url=http://dl-www.sonyericsson.com/cws/download/1/922/663/1315211190/pro_WP_13.pdf |archive-url=https://web.archive.org/web/20120425091518/http://dl-www.sonyericsson.com/cws/download/1/922/663/1315211190/pro_WP_13.pdf |archive-date=2012-04-25 |url-status=live|title=Sony Xperia support (English)|website=sonyericsson.com|access-date=2 September 2015}}
  • ZTE
  • Huawei{{cite web|url=http://www.cnews.ru/news/top/index.shtml?2011/02/15/427617|title=Sony Ericsson и Huawei готовят смартфоны с ГЛОНАСС|work=CNews.ru|access-date=2 September 2015|url-status=dead |archive-url=https://web.archive.org/web/20150723064735/http://www.cnews.ru/news/top/index.shtml?2011%2F02%2F15%2F427617|archive-date=23 July 2015}}
  • Samsung{{cite web|url=http://www.samsung.com/global/microsite/galaxynote/note/spec.html|title=Samsung GALAXY Note|website=samsung.com|access-date=2 September 2015|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304111834/http://www.samsung.com/global/microsite/galaxynote/note/spec.html|url-status=live}}
  • Apple (since iPhone 4S, concurrently with GPS)
  • HTC[http://www.htc.com/www/smartphones/htc-wp-8x/#specs Windows Phone 8X by HTC Overview - HTC Smartphones] {{Webarchive|url=https://web.archive.org/web/20140209181714/http://www.htc.com/www/smartphones/htc-wp-8x/#specs |date=9 February 2014 }}, htc.com, Retrieved on 2 August 2013
  • LG[https://docs.google.com/viewer?url=http%3A%2F%2Fwww.qualcomm.com%2Fsites%2Fdefault%2Ffiles%2Fcommon%2Fproducts-services%2Fsnapdragon_specs_9-12.pdf Google Drive Viewer] {{Webarchive|url=https://web.archive.org/web/20160417144445/https://docs.google.com/viewer?url=http%3A%2F%2Fwww.qualcomm.com%2Fsites%2Fdefault%2Ffiles%2Fcommon%2Fproducts-services%2Fsnapdragon_specs_9-12.pdf |date=17 April 2016 }}, docs.google.com, Retrieved on 2 August 2013
  • Motorola{{cite web|url=http://mediacenter.motorola.com/Fact-Sheets/DROID-RAZR-by-Motorola-Fact-Sheet-386c.aspx|title=The Official Motorola Blog|website=motorola.com|access-date=2 September 2015|archive-date=15 June 2013|archive-url=https://web.archive.org/web/20130615084229/http://mediacenter.motorola.com/Fact-Sheets/DROID-RAZR-by-Motorola-Fact-Sheet-386c.aspx|url-status=live}}
  • Nokia{{cite news|url=https://www.reuters.com/article/us-russia-glonass-idUSTRE7783VU20110809|title=GLONASS gets Nokia backing, aims to rival COMPASS|newspaper=Reuters|access-date=2 September 2015|date=9 August 2011|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924154559/http://www.reuters.com/article/2011/08/09/us-russia-glonass-idUSTRE7783VU20110809|url-status=live}}

Status

= Availability =

File:GPSTest screenshot (2025).webp, Indonesia (2025)]]

{{as of|2024|February|17}}, the GLONASS constellation status is:{{cite web |title=Constellation status |url=https://glonass-iac.ru/en/sostavOG/ |access-date=2024-02-17 |website=glonass-iac.ru }}

class="wikitable" style="text-align:center;"
style="text-align:left;"| Total

| 26 SC

style="text-align:left;"| Operational

| 24 SC (Glonass-M/K)

style="text-align:left;"| In commissioning

| 0 SC

style="text-align:left;"| In maintenance

| 0 SC

style="text-align:left;"| Under check by the Satellite Prime Contractor

| 0 SC

style="text-align:left;"| Spares

| 0 SC

style="text-align:left;"| In flight tests phase

| 2 SC

The system requires 18 satellites for continuous navigation services covering all of Russia, and 24 satellites to provide services worldwide.{{citation needed|date=February 2023}} The GLONASS system covers 100% of worldwide territory.

On 2 April 2014, the system experienced a technical failure that resulted in practical unavailability of the navigation signal for around 12 hours.{{cite news|url=http://izvestia.ru/news/568647|title=Роскосмос ищет причины сбоя ГЛОНАСС|newspaper=Izvestia|year=2014|access-date=5 April 2014|archive-date=25 December 2015|archive-url=https://web.archive.org/web/20151225113907/http://izvestia.ru/news/568647|url-status=live}}

On 14–15 April 2014, nine GLONASS satellites experienced a technical failure due to software problems.{{cite news|url=https://www.novayagazeta.ru/news/2014/04/15/99404-sistema-glonass-vyshla-iz-stroya-vtoroy-raz-za-mesyats|title=Система ГЛОНАСС вышла из строя второй раз за месяц|newspaper=Новая Газета |year=2014|access-date=10 March 2019|archive-date=2 April 2019|archive-url=https://web.archive.org/web/20190402153920/https://www.novayagazeta.ru/news/2014/04/15/99404-sistema-glonass-vyshla-iz-stroya-vtoroy-raz-za-mesyats|url-status=live}}

On 19 February 2016, three GLONASS satellites experienced a technical failure: the batteries of GLONASS-738 exploded, the batteries of GLONASS-737 were depleted, and GLONASS-736 experienced a stationkeeping failure due to human error during maneuvering. GLONASS-737 and GLONASS-736 were expected to be operational again after maintenance, and one new satellite (GLONASS-751) to replace GLONASS-738 was expected to complete commissioning in early March 2016. The full capacity of the satellite group was expected to be restored in the middle of March 2016.{{cite news|url=http://izvestia.ru/news/604492|title=Роскосмос обещает восстановить ГЛОНАСС к середине марта|newspaper=Известия |date=18 February 2016|access-date=26 February 2016|archive-date=27 February 2016|archive-url=https://web.archive.org/web/20160227002848/http://izvestia.ru/news/604492|url-status=live}}

After the launching of two new satellites and maintenance of two others, the full capacity of the satellite group was restored.

= Accuracy =

According to Russian System of Differentional Correction and Monitoring's data, {{as of|2010|lc=on}}, precision of GLONASS navigation definitions (for p=0.95) for latitude and longitude were {{cvt|4.46|–|7.38|m}} with mean number of navigation space vehicles (NSV) equals 7—8 (depending on station). In comparison, the same time precision of GPS navigation definitions were {{cvt|2.00|–|8.76|m}} with mean number of NSV equals 6—11 (depending on station).

Some modern receivers are able to use both GLONASS and GPS satellites together, providing greatly improved coverage in urban canyons and giving a very fast time to fix due to over 50 satellites being available. In indoor, urban canyon or mountainous areas, accuracy can be greatly improved over using GPS alone. For using both navigation systems simultaneously, precision of GLONASS/GPS navigation definitions were {{cvt|2.37|–|4.65|m}} with mean number of NSV equals 14—19 (depends on station).

In May 2009, Anatoly Perminov, then director of the Roscosmos, stated that actions were undertaken to expand GLONASS's constellation and to improve the ground segment to increase the navigation definition of GLONASS to an accuracy of {{cvt|2.8|m}} by 2011.{{cite web|url=http://www.rian.ru/science/20090512/170848130.html|title=Роскосмос обещает повысить точность работы ГЛОНАСС с 10 до 5,5 метров|date=12 May 2009|publisher=РИА Новости|access-date=2 September 2015|archive-date=29 May 2010|archive-url=https://web.archive.org/web/20100529064042/http://www.rian.ru/science/20090512/170848130.html|url-status=live}} In particular, the latest satellite design, GLONASS-K has the ability to double the system's accuracy once introduced. The system's ground segment is also to undergo improvements. As of early 2012, sixteen positioning ground stations are under construction in Russia and in the Antarctic at the Bellingshausen and Novolazarevskaya bases. New stations will be built around the southern hemisphere from Brazil to Indonesia. Together, these improvements are expected to bring GLONASS' accuracy to 0.6 m or better by 2020.{{cite news|url=http://rbth.ru/articles/2012/02/16/glonass_benefits_worth_the_extra_expense_14862.html|title=GLONASS benefits worth the extra expense|last1=Kramnik|first1=Ilya|newspaper=Russia Beyond the Headlines|date=2012-02-16|access-date=22 February 2012|archive-date=22 February 2012|archive-url=https://web.archive.org/web/20120222100105/http://rbth.ru/articles/2012/02/16/glonass_benefits_worth_the_extra_expense_14862.html|url-status=live}} The setup of a GLONASS receiving station in the Philippines is also now under negotiation.{{cite news|title=DOST Finalizes MOU with Russian Space Agency|url=https://www.dfa.gov.ph/dfa-news/news-from-our-foreign-service-postsupdate/17790-dost-finalizes-mou-with-russian-space-agency|access-date=24 September 2018|publisher=Department of Foreign Affairs (Philippines)|date=7 September 2018|archive-date=25 September 2018|archive-url=https://web.archive.org/web/20180925104330/https://www.dfa.gov.ph/dfa-news/news-from-our-foreign-service-postsupdate/17790-dost-finalizes-mou-with-russian-space-agency|url-status=live}}

History

{{main|History of GLONASS}}

See also

Notes

{{notelist}}

References

{{Reflist|refs=

{{cite web|url=http://www.unoosa.org/documents/pdf/psa/activities/2015/RussiaGNSS/Presentations/1.pdf |archive-url=https://web.archive.org/web/20160923014654/http://www.unoosa.org/documents/pdf/psa/activities/2015/RussiaGNSS/Presentations/1.pdf |archive-date=2016-09-23 |url-status=live|last=Testoyedov|first=Nikolay|title=Space Navigation in Russia: History of Development|date=2015-05-18|access-date=2016-09-21}}

{{cite web|url=http://www.iss-reshetnev.com/media/news/news-300715|title=Glonass-M – a chapter in the history of satellite navigation|publisher=JSC Information Satellite Systems|date=2015-07-30|access-date=2015-08-13|archive-date=28 May 2016|archive-url=https://web.archive.org/web/20160528232727/http://www.iss-reshetnev.com/media/news/news-300715|url-status=live}}

{{cite news|url=http://tass.ru/en/non-political/811771|title=Russia stops manufacturing of Glonass-M navigation satellites|publisher=ITAR-TASS|date=2015-07-30|access-date=2015-08-20|archive-date=1 August 2015|archive-url=https://web.archive.org/web/20150801020451/http://tass.ru/en/non-political/811771|url-status=live}}

}}

Standards

  • {{cite web|date=2008|url=http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD_GLONASS_rus_v5.1.pdf|title=GLONASS Interface Control Document, Navigational radio signal in bands L1, L2 (Edition 5.1)|publisher=Russian Space Systems OJSC|access-date=2016-10-21|language=ru|archive-date=21 October 2011|archive-url=https://web.archive.org/web/20111021141150/http://www.aggf.ru/gnss/glon/ikd51ru.pdf|url-status=dead}}
  • {{cite web|date=2016|url=http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L1-s-kod.-razd.-Red-1.0-2016.pdf|title=GLONASS Interface Control Document, Open CDMA navigational radio signal in L1 band, Edition 1.0|publisher=Russian Space Systems OJSC|access-date=2016-10-21|language=ru|archive-date=22 October 2016|archive-url=https://web.archive.org/web/20161022090547/http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L1-s-kod.-razd.-Red-1.0-2016.pdf|url-status=dead}}
  • {{cite web|date=2016|url=http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L2-s-kod.-razd.-Red-1.0-2016.pdf|title=GLONASS Interface Control Document, Open CDMA navigational radio signal in L2 band, Edition 1.0|publisher=Russian Space Systems OJSC|access-date=2016-10-21|language=ru|archive-date=22 October 2016|archive-url=https://web.archive.org/web/20161022092222/http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L2-s-kod.-razd.-Red-1.0-2016.pdf|url-status=dead}}
  • {{cite web|date=2016|url=http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L3-s-kod.-razd.-Red-1.0-2016.pdf|title=GLONASS Interface Control Document, Open CDMA navigational radio signal in L3 band, Edition 1.0|publisher=Russian Space Systems OJSC|access-date=2016-10-21|language=ru|archive-date=22 October 2016|archive-url=https://web.archive.org/web/20161022091912/http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD-L3-s-kod.-razd.-Red-1.0-2016.pdf|url-status=dead}}
  • {{cite web|date=2016|url=http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD.-Obshh.-opis.-Red.-1.0-2016.pdf|title=GLONASS Interface Control Document, General description of CDMA signals, Edition 1.0|publisher=Russian Space Systems OJSC|access-date=2016-10-21|language=ru|archive-date=22 October 2016|archive-url=https://web.archive.org/web/20161022090410/http://russianspacesystems.ru/wp-content/uploads/2016/08/IKD.-Obshh.-opis.-Red.-1.0-2016.pdf|url-status=dead}}

Bibliography

  • [https://web.archive.org/web/20161020203029/http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD_GLONASS_eng_v5.1.pdf GLONASS Interface Control Document, Edition 5.1, 2008] ([https://web.archive.org/web/20120710133600/http://facility.unavco.org/data/docs/ICD_GLONASS_5.1_(2008)_en.pdf backup])
  • [https://www.unavco.org/help/glossary/docs/ICD_GLONASS_4.0_(1998)_en.pdf GLONASS Interface Control Document, Version 4.0, 1998]
  • {{cite web|publisher=Russian Federal Government|title=ФЕДЕРАЛЬНАЯ ЦЕЛЕВАЯ ПРОГРАММА "ГЛОБАЛЬНАЯ НАВИГАЦИОННАЯ СИСТЕМА", FEDERAL SPECIAL-PURPOSE PROGRAM "GLOBAL NAVIGATION SYSTEM"|date=2001-08-20

|language=ru|url= http://www.programs-gov.ru/26_1.php|access-date=2007-04-10|archive-url=https://web.archive.org/web/20070927190908/http://www.programs-gov.ru/ext/117/content.htm|archive-date=27 September 2007}}

  • {{cite web|publisher=Russian Space Agency (RSA)|title=GLONASS constellation status for 18.01.08 under the analysis of the almanac and accepted in IANC (UTC)|url=http://www.glonass-ianc.rsa.ru/pls/htmldb/f?p=202:20:4969607893141445194::NO|access-date=2008-01-18|url-status=dead|archive-url=https://web.archive.org/web/20071024172738/http://www.glonass-ianc.rsa.ru/pls/htmldb/f?p=202:20:4969607893141445194::NO

|archive-date=24 October 2007}}

  • {{cite web|publisher=Space and Tech|title=GLONASS Summary|url=http://www.spaceandtech.com/spacedata/constellations/glonass_consum.shtml|access-date=2007-04-12|url-status=usurped |archive-url=https://web.archive.org/web/20070426101716/http://www.spaceandtech.com/spacedata/constellations/glonass_consum.shtml|archive-date=26 April 2007}}
  • {{cite web|title=GLONASS Transmitter Specifications|url=http://www.atnf.csiro.au/people/dmitchel/glonass.html|access-date=2007-04-13 |archive-url=https://web.archive.org/web/20070613234101/http://www.atnf.csiro.au/people/dmitchel/glonass.html|archive-date=2007-06-13}}
  • {{cite web|last=Goebel|first=Greg|title=Navigation Satellites & GPS|pages=Section 2.2|url=http://www.vectorsite.net/ttgps.html|access-date=2007-04-10

|archive-url=https://web.archive.org/web/20181022114901/http://vectorsite.net/ttgps.html|archive-date=22 October 2018|url-status=usurped}}

  • {{cite web|publisher=Russian Space Agency (RSA)|title=Интегральная доступность навигации наземного потребителя по системе ГЛОНАСС Integral accessibility of the navigation of ground-based user along the system GLONASS|language=ru|url=http://www.glonass-ianc.rsa.ru/pls/htmldb/f?p=201:24:5771576984142464179::NO:::|access-date=2008-01-18|url-status=dead |archive-url=https://web.archive.org/web/20071024172737/http://www.glonass-ianc.rsa.ru/pls/htmldb/f?p=201:24:5771576984142464179::NO:::|archive-date=24 October 2007}}
  • {{cite news|title=India joins Russian GPS system|newspaper=The Times of India|date=2007-01-29|url=http://timesofindia.indiatimes.com/India_joins_Russian_GPS_system/articleshow/1502481.cms|access-date=2007-04-12}}
  • {{Cite news|title=India to Launch 2 Russian GLONASS Satellites|publisher=MosNews|date=2005-06-27|url=http://www.mosnews.com/news/2005/06/27/indialaunch.shtml

|archive-url=https://archive.today/20051121193827/http://www.mosnews.com/news/2005/06/27/indialaunch.shtml|url-status=usurped|archive-date=2005-11-21|access-date=2007-04-12}}

  • {{cite web|publisher=GPS/GLONASS Interoperability and Compatibility Working Group|title=Joint announcement (in English and Russian)|url=http://pnt.gov/public/docs/2006-WG1-statement.shtml|date=2006-12-14

|access-date=2007-04-13|archive-url=https://web.archive.org/web/20070919124045/http://pnt.gov/public/docs/2006-WG1-statement.shtml|archive-date=2007-09-19}}

  • {{cite news|last=Kramer|first=Andrew E.|title=Russia Challenges the U.S. Monopoly on Satellite Navigation|newspaper=The New York Times|date=2007-04-07 |url=https://www.nytimes.com/2007/04/04/business/worldbusiness/04gps.html|access-date=2007-04-12}}
  • {{Cite journal|last=Miller|first=Keith M.|title=A Review of GLONASS|journal=Hydrographic Society Journal|date=October 2000|url=http://www.hydrographicsociety.org/Articles/journal/2000/98-1.htm

|access-date=2007-04-13|archive-url=https://web.archive.org/web/20071012120024/http://www.hydrographicsociety.org/Articles/journal/2000/98-1.htm|issue=98|issn=0309-7846|archive-date=2007-10-12}}

  • {{Cite news|title=Radical Change in the Air for GLONASS|publisher=GPS World|date=2007-01-22|url=http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=399504|access-date=2007-04-10 |archive-url=https://web.archive.org/web/20070210065953/http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=399504|archive-date=2007-02-10}}
  • {{Cite news|title=Russia Allocates US$380 Million for Global Navigation System in 2007|publisher=MosNews|date=2007-03-26|url=http://mosnews.com/news/2007/03/26/glonass.shtml|archive-url=https://web.archive.org/web/20220421193356/http://mosnews.com/news/2007/03/26/glonass.shtml|url-status=usurped|archive-date=21 April 2022|access-date=2007-04-12}}
  • {{Cite news|title=Russia Holds First Place in Spacecraft Launches|publisher=MosNews|date=2007-03-26|url=http://mosnews.com/news/2007/03/26/glonass.shtml|archive-url=https://web.archive.org/web/20220421193356/http://mosnews.com/news/2007/03/26/glonass.shtml|url-status=usurped|archive-date=21 April 2022|access-date=2007-04-12}}
  • {{Cite news|title=Russia Launches New Navigation Satellites into Orbit|publisher=Space.com / Associated Press|date=2007-12-25|url=http://www.space.com/missionlaunches/ap-071225-proton-glonass.html|access-date=2007-12-28|url-status=dead|archive-url=https://web.archive.org/web/20080828015513/http://www.space.com/missionlaunches/ap-071225-proton-glonass.html|archive-date=28 August 2008}}
  • {{Cite news|title=Russian Space Agency Plans Cooperation With India|publisher=MosNews|date=2004-01-12|url=http://www.mosnews.com/news/2004/12/01/indiaspace.shtml|archive-url=https://archive.today/20050207140740/http://www.mosnews.com/news/2004/12/01/indiaspace.shtml|url-status=usurped|archive-date=2005-02-07|access-date=2007-04-12}}
  • {{cite web|publisher=Federation of American Scientists|title=Space Policy Project's "World Space Guide: GLONASS"|url=https://fas.org/spp/guide/russia/nav/glonass.htm|access-date=2007-04-10|url-status=dead |archive-url=https://web.archive.org/web/20070403015512/http://www.fas.org/spp/guide/russia/nav/glonass.htm|archive-date=3 April 2007}}
  • {{Cite news|title=Услуги системы ГЛОНАСС будут предоставляться потребителям бесплатно The services of system GLONASS will be given to users free of charge|language=ru|publisher=RIA Novosti

|date=2007-05-18|url=https://ria.ru/science/20070518/65722212.html|access-date=2007-05-18}}

  • {{cite web|publisher=Russian Space Agency (RSA)|title=Три КА "Глонасс-М" взяты на управление Three KA "GLONASS-M" have taken off|language=ru|date=2006-12-26 |url=http://www.roscosmos.ru/NewsDoSele.asp?NEWSID=2021|access-date=2006-12-29|archive-url=https://web.archive.org/web/20070927230705/http://www.roscosmos.ru/NewsDoSele.asp?NEWSID=2021|archive-date=2007-09-27 |url-status=dead}}
  • {{cite web|publisher=Gunter's Space Page|title=Uragan (GLONASS, 11F654)|date=2007-01-16|url=http://space.skyrocket.de/doc_sdat/uragan.htm|access-date=2007-04-10}}
  • {{cite web|publisher=Russian Space Web|title=Uragan navsat (11F654)|url=http://www.russianspaceweb.com/uragan.html|access-date=2007-04-12|url-status=dead |archive-url=https://web.archive.org/web/20160303171219/http://www.russianspaceweb.com/uragan.html|archive-date=3 March 2016}}
  • {{cite web|title=GLONASS News|url=http://www.gpssoft.ru/glonass/|access-date=2007-07-31}}