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|Category=GLONASS
|Category=GLONASS
|Title={{PAGENAME}}
|Editors=GMV
|Authors=GMV
|Level=Basic
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|YearOfPublication=2011
|YearOfPublication=2011
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The Government of the Russian Federation,  acknowledging that navigation satellite system [[:Category:GLONASS|GLONASS]] was a top priority, approved by its Decree No. 587 of 20 August 2001, a Federal Task Program on the Global Navigation System (GNS) <ref>[http://groups.itu.int/Portals/19/activeforums_Attach/GLONASS%20Commitment%20Ltr.pdf Federal Task Program on the Global Navigation System]</ref>. The GNS Program aims at improving both the space, ground-based and user equipment segments of the [[:Category:GLONASS|GLONASS]] system.
Actually the program aims at ensuring that [[:Category:GLONASS|GLONASS]]  performances are similar to those of GPS.
The fact that [[:Category:GLONASS|GLONASS]] performances are worse than those of GPS are due to several factors, including the performances of the on-board atomic clocks, the number of satellites in the constellation and the fact that ground segment monitoring and control was limited to the Russian territory. By 2010, GLONASS reached full coverage in Russian territory and in 2011 full operational capability with the full orbital constellation of 24 satellites. GLONASS had a 347 billion ruble (US$11.81) budget approved through 2020, by which time the system is scheduled to have all satellites transmitting both the new CDMA and legacy FDMA signals<ref name="Munich2012">[http://insidegnss.com/munich-summit-charts-progress-of-gps-glonass-galileo-beidou-gnsses/ Munich Summit Charts Progress of GPS, GLONASS, Galileo, Beidou GNSSes, InsideGNSS, March 2012]</ref>.
==Signal Modernization==
[[File:Galileo Signals in Space.png|250px|GNSS Signal Frequencies|right|thumb]]
Traditionally, [[:Category:GLONASS|GLONASS]] satellites transmit navigational radio signals on two frequency sub-bands (L1 ~ 1602 MHz and L2 ~ 1246 MHz), relying on the Frequency Division Multiple Access (FDMA) technique in contrast to CDMA employed by all the other GNSS systems.
Aiming to provide better accuracy, multipath resistance and especially, greater interoperability with [[:Category:GPS|GPS]] and future [[:Category:GALILEO|GALILEO]] and other GNSS Systems, new GLONASS-K satellites will transmit CDMA signals in addition to the  system’s traditional FDMA.
In fact, since the successful launch of the first GLONASS K1 satellite, <ref>[http://insidegnss.com/russias-first-glonass-k-in-orbit-cdma-signals-coming/ Russia’s First GLONASS-K In Orbit, CDMA Signals Coming, insideGNSS]</ref> a new L3 CDMA signal is already being transmitting and tracked by several receiver companies.
The GLONASS L3 signal is centered at 1207.14 MHz, the same frequency as Galileo/BeiDou signal E5b, in the region allocated to the Aeronautical Radio 1 Navigation Service (ARNS). These bands are especially suitable for Safety-of-Life applications because no other users are allowed to interfere with their signals.
The future GLONASS K2 satellites will feature four additional CDMA signals along the original FDMA signals. Two of them are obfuscated signals located at 1242 MHz (L2 band) and 1575.42 MHz (L1 band) for military uses and the other two are open signals located at 1575.42 MHz (L1 band) and 1207.14 MHz (L3 band) for civil uses.<ref name="Modernization">[http://www.unoosa.org/documents/pdf/psa/activities/2012/un-latvia/ppt/1-2.pdf GLONASS Status and Modernization]</ref>
A modernized GLONASS-K satellite, GLONASS-KM, for launch after 2015 <ref name="ConstellationUpdate">[to http://gpsworld.com/ GLONASS Update Delves into Constellation Details, GPSworld]</ref> may also transmit on the L5 frequency at 1176.45 MHz, the same as the modernized GPS signal L5 and Galileo signal E5a.
==Space Segment==
[[File:GLONASS_SpaceSegmentModernization.JPG|400px|GLONASS Space Segment Modernization|right|thumb]]
[[:GLONASS Space Segment|GLONASS Space Segment]] modernization, began with the second generation of satellites, GLONASS-M. Reserved bytes in the navigation message were used to provide the divergence of GPS and GLONASS time scales, the navigation frame authenticity (validity) flags, and age of data information.<ref name="GLONASS_OnceAndFuture">[http://insidegnss.com/glonass-the-once-and-future-gnss/ GLONASS: The Once and Future GNSS, InsideGNSS]</ref> New filters allowed the reduction of out-of-band emissions and on-board clock stability over 24 hours was improved from 5x10-13 to 1x10-13.
A GLONASS-M satellite was launched in April 2013 already planned as a reserve to replace older units.
The first satellite of the third generation, GLONASS-K1, was launched on February 26 2011 while the second one was launched only on November, 30, 2014. The second launch suffered a lot of technical difficulties and should have closed its satellites generation. However, the plan was adjusted and according to Nikolai Testoyedov, CEO of Information Satellite Systems Reshetnev, it is scheduled to be launched another 9 GLONASS-K1 satellites<ref>[2nd GLONASS-K1 Finally Reaches Space], Inside GNSS, December 2, 2014</ref> which have a 10-year design life and carries a CDMA civil signal at L3 band in the 1205 MHz frequency<ref name=glonass-k1-2>[http://gpsworld.com/glonass-k1-to-replace-an-existing-glonass-m-in-six-months/ GLONASS-K1 to Replace an Existing GLONASS-M in Six Months], GPS World, December 15, 2014</ref>. The second GLONASS-K1 began regular broadcasts on February 15, 2016, on channel –6 from its orbital location in plane 2, slot 9 of the GLONASS constellation.<ref>[http://insidegnss.com/first-glonass-k-satellite-enters-service/ First GLONASS-K Satellite Enters Service]</ref>
The initial plan was start launching the completely designed from scratch GLONASS-K2 satellites generation by 2014, however the plan was adjusted and the first launch has postponed to 2018<ref name=glonass-k1-2/><ref>[http://gpsworld.com/first-launch-of-glonass-k2-satellite-planned-for-2018/ First Launch of GLONASS-K2 Satellite Planned for 2018], GPS World, April 2, 2015</ref>. The GLONASS-K2 satellites will have a 10-year design life and a clock stability of ~5-1x10-14. In addition to CDMA signals on L3, CDMA signals will also be transmitted on L1 and L2. The GLONASS-K satellites will transmit both legacy FDMA and CDMA signals<ref name="Modernization"></ref>.
As reported in <ref name="GLONASS_OnceAndFuture"/>, a modernized GLONASS-K satellite (GLONASS-KM) could transmit (no sooner than 2015) legacy FDMA signals on L1 and L2 and CDMA signals on L1, L2, and L3. It could also transmit CDMA signals on the GPS L5 frequency at 1176.45 MHz. GNSS integrity information could also be broadcast in the third civil signal and global differential ephemeris and time corrections.
Also being studied is an alternative to the present three-plane, equally spaced satellite constellation, which would also require the legacy FDMA signals be switched off.<ref name="ConstellationUpdate"/><br>
On February 8, 2016, a new GLONASS satellite was launched, intended to replace a 10-year old satellite that ceased operations last October in slot 17, orbital plane 3 of the GLONASS constellation.<ref>[http://insidegnss.com/russia-launches-first-glonass-m-in-more-than-a-year/ Russia Launches First GLONASS-M in More Than a Year]</ref>
Another GLONASS-M satellite was launched sucessfully on May 29, 2016, despite some irregularities with its launcher.
<ref>[http://insidegnss.com/new-glonass-m-survives-slight-glitch-to-reach-orbit/ New GLONASS-M Survives Slight Glitch to Reach Orbit]</ref> The satellite became operational on June 27, 2016.<ref>[http://insidegnss.com/recently-launched-glonass-m-becomes-operational/ Recently Launched GLONASS-M Becomes Operational]</ref>


In 2001, there were only seven GLONASS operational satellites in orbit. Acknowledging that navigation satellite system GLONASS was a top priority, the Government of the Russian Federation, by its Decree No. 587 of 20 August 2001, approved a Federal Task Program on the Global Navigation System (GNS) <ref>[http://groups.itu.int/Portals/19/activeforums_Attach/GLONASS%20Commitment%20Ltr.pdf Federal Task Program on the Global Navigation System]</ref>. The GNS Program covers improvement of space, ground-based and user equipment segments of the GLONASS system.
==Ground Segment==
One of the main objectives of the Program is to ensure GLONASS performance similar to GPS by the end of 2011. GLONASS poorer performance is the culmination of several factors:<ref name="GlonassFuture_InsideGNSS">[http://www.insidegnss.com/node/591 Russia Dwells on Glonass Future, InsideGNSS]</ref>
Fifteen new reference statiosn will be added, six of them outside the Russian territory, being the first one already placed in Antarctica.<ref>[http://gpsworld.com/ GLONASS Up to Date and Out of State, GPSWorld]</ref>
* poorer on-board atomic clocks
* less stability and predictability in the satellite orbits (and therefore less accuracy in GLONASS broadcast ephemerides)
* fewer satellites providing signals
* operational control and ground monitoring segment limited to Russian territory,


The Program is scheduled to end in 2011, however the Federal Spacy Agency has already announced that the maintenance and development of GLONASS will be extended until 2020, and will cost 402 billion rubles ($14.35 billion).<ref name="GLONASS_Finances">[http://www.insidegnss.com/node/2656 GLONASS, Galileo Finances Star at Paris Air Show, InsideGNSS]</ref>
Also, the developments of both the [[:Category:GLONASS|GLONASS]] tracking capabilities as well as the steady increase in the number of [[:Category:GLONASS|GLONASS]] satellites, has had a positive influence on the accuracy of the [[:Category:GLONASS|GLONASS]] orbits and clocks. For instance, according to the GPSWorld article “Innovation: GPS, GLONASS, and More”<ref>[http://gpsworld.com/innovation-gps-glonass-and-more/ Innovation: GPS, GLONASS, and More, GPSWorld]</ref> in 2008, the orbit quality, was at the 120-millimeter level (cross-track), which was improved significantly to the 85-millimeter level by the end of 2009.


==Signal Modernization==
Aiming to improve the interoperability with other GNSS systems, [[Reference Frames in GNSS|GLONASS coordinate system]] has been tied to the International Terrestrial Reference System (ITR), an international standard.  The ephemeris information implementing the [[Reference_Frames_in_GNSS#GLONASS_reference_frame_PZ-90 | PZ-90.11]] reference system has been implemented on all operational GLONASS satellites starting from 3:00 pm on December 31, 2013<ref>[http://www.glonass-iac.ru/en/content/news/?ELEMENT_ID=721 The transition to using the terrestrial geocentric coordinate system PZ-90.11 in operating GLONASS system has been implemented], Russian Federal Space Agency, Information-analytical centre, 4 April 2014</ref>. From this time on, the satellites are broadcasting in the PZ-90.11. This ECEF reference frame is an updated version of PZ-90, closest to the ITRF2008.
Traditionally, GLONASS satellites transmits navigational radiosignals on two frequency sub-bands (L1 ~ 1602 MHz and L2 ~ 1246 MHz), relying on the Frequency Division Multiple Access (FDMA) technique in contrast to CDMA employed by all the other GNSS systems.


Aiming to provide better accuracy, multipath resistance and especially, greater interoperability with GPS and future GALILEO and other GNSS Systems, new GLONASS-K satellites will transmit CDMA signals in addition to the  system’s traditional FDMA.
On March 6th, 2017, a new GLONASS station was officially commissioned in South Africa. That station will monitor GLONASS and GPS satellites’ navigation signals, measurements of current navigation parameters of their travel, and receipt of navigation messages from the satellites.<ref>[http://gpsworld.com/glonass-ground-station-goes-live-in-south-africa/ GLONASS ground station goes live in South Africa]</ref>
In fact, since the successful launch of the first GLONASS K1 satellite, <ref>[http://www.insidegnss.com/node/2487 Russia’s First GLONASS-K In Orbit, CDMA Signals Coming, insideGNSS]</ref>, a new L3 CDMA signal is already being transmitting and tracked by several receiver companies.
The GLONASS L3 signal is centered at 1207.14 MHz, the same frequency as Galileo/COMPASS signal E5b, in the region allocated to the Aeronautical Radio 1 Navigation Service (ARNS). These bands are especially suitable for Safety-of-Life applications because no other users are allowed to interfere with their signals.


The future GLONASS K2 satellites to be launched in 2013, will feature three additional CDMA signals near the original FDMA frequencies, one obfuscated signal located at 1242 MHz in the L2 band, as well as two signals at 1575.42 MHz in the L1 band.
==User Segment==
Although the [[:Category:GLONASS|GLONASS]] constellation is nearing global coverage, its commercialization, especially development of the user segment, has been lacking compared to the U.S. GPS system.<ref name="GLONASS_Wikipedia">[http://en.wikipedia.org/wiki/GLONASS GLONASS on Wikipedia]</ref> To improve the situation, the Russian government has been actively promoting GLONASS for civilian use. According to the Decree of the Government of Russian Federation “About use of GLONASS in technical system and transport vehicles”, August 25 2008, N 641, <ref>[https://www.finpro.fi/c/document_library/get_file?uuid=3a5b031d-b8c7-4c14-88c4-6b91aba76e6f&groupId=10304 FinNode-Services to Russian GLONASS Position system, FINPRO]</ref> GLONASS devices should be used in:
* All spacecraft and separate components of them;
* All civilian and experimental aircraft;
* All river- and see-going vessels;
* All railway and road vehicles for cargo- and passenger transportation;
* All vehicles for transport of dangerous payload;
* All surveying and map-making equipment;
* All devices for time synchronization;


A modernized GLONASS-K satellite, GLONASS-KM, for launch after 2015 <ref>[http://www.gpsworld.com/gnss-system/glonass/news/glonass-update-delves-constellation-details-10499 GLONASS Update Delves into Constellation Details, GPSworld]</ref> may also transmit on the GPS L5 frequency at 1176.45 MHz, the same as the modernized GPS signal "Safety of Life" (L5) and Galileo signal E5a.
GLONASS will be used for road tax collection and roadside assistance. Vehicles sold in Russian Federation (starting from 2013) will feature a tracking system (known as ERA-GLONASS project) that will act as a black box device with the capability of alerting Emergency Centers in the event of an accident providing the precise position of the vehicle in question. This is expected to reduce emergency arrivel times by 30% on average. Please refer to <ref>[http://www.nis-glonass.ru/en/project/era_glonass/index.php NIS-GLONASS, ERA project]</ref> for further information.


==Notes==
==Notes==
Line 33: Line 68:
<references/>
<references/>


[[Category:GLONASS|GLONASS Architecture]]
[[Category:GLONASS]]

Latest revision as of 11:39, 21 May 2021


GLONASSGLONASS
Title GLONASS Future and Evolutions
Edited by GMV
Level Basic
Year of Publication 2011
Logo GMV.png

The Government of the Russian Federation, acknowledging that navigation satellite system GLONASS was a top priority, approved by its Decree No. 587 of 20 August 2001, a Federal Task Program on the Global Navigation System (GNS) [1]. The GNS Program aims at improving both the space, ground-based and user equipment segments of the GLONASS system. Actually the program aims at ensuring that GLONASS performances are similar to those of GPS. The fact that GLONASS performances are worse than those of GPS are due to several factors, including the performances of the on-board atomic clocks, the number of satellites in the constellation and the fact that ground segment monitoring and control was limited to the Russian territory. By 2010, GLONASS reached full coverage in Russian territory and in 2011 full operational capability with the full orbital constellation of 24 satellites. GLONASS had a 347 billion ruble (US$11.81) budget approved through 2020, by which time the system is scheduled to have all satellites transmitting both the new CDMA and legacy FDMA signals[2].


Signal Modernization

GNSS Signal Frequencies

Traditionally, GLONASS satellites transmit navigational radio signals on two frequency sub-bands (L1 ~ 1602 MHz and L2 ~ 1246 MHz), relying on the Frequency Division Multiple Access (FDMA) technique in contrast to CDMA employed by all the other GNSS systems.

Aiming to provide better accuracy, multipath resistance and especially, greater interoperability with GPS and future GALILEO and other GNSS Systems, new GLONASS-K satellites will transmit CDMA signals in addition to the system’s traditional FDMA. In fact, since the successful launch of the first GLONASS K1 satellite, [3] a new L3 CDMA signal is already being transmitting and tracked by several receiver companies. The GLONASS L3 signal is centered at 1207.14 MHz, the same frequency as Galileo/BeiDou signal E5b, in the region allocated to the Aeronautical Radio 1 Navigation Service (ARNS). These bands are especially suitable for Safety-of-Life applications because no other users are allowed to interfere with their signals.

The future GLONASS K2 satellites will feature four additional CDMA signals along the original FDMA signals. Two of them are obfuscated signals located at 1242 MHz (L2 band) and 1575.42 MHz (L1 band) for military uses and the other two are open signals located at 1575.42 MHz (L1 band) and 1207.14 MHz (L3 band) for civil uses.[4]

A modernized GLONASS-K satellite, GLONASS-KM, for launch after 2015 [5] may also transmit on the L5 frequency at 1176.45 MHz, the same as the modernized GPS signal L5 and Galileo signal E5a.

Space Segment

GLONASS Space Segment Modernization

GLONASS Space Segment modernization, began with the second generation of satellites, GLONASS-M. Reserved bytes in the navigation message were used to provide the divergence of GPS and GLONASS time scales, the navigation frame authenticity (validity) flags, and age of data information.[6] New filters allowed the reduction of out-of-band emissions and on-board clock stability over 24 hours was improved from 5x10-13 to 1x10-13. A GLONASS-M satellite was launched in April 2013 already planned as a reserve to replace older units.

The first satellite of the third generation, GLONASS-K1, was launched on February 26 2011 while the second one was launched only on November, 30, 2014. The second launch suffered a lot of technical difficulties and should have closed its satellites generation. However, the plan was adjusted and according to Nikolai Testoyedov, CEO of Information Satellite Systems Reshetnev, it is scheduled to be launched another 9 GLONASS-K1 satellites[7] which have a 10-year design life and carries a CDMA civil signal at L3 band in the 1205 MHz frequency[8]. The second GLONASS-K1 began regular broadcasts on February 15, 2016, on channel –6 from its orbital location in plane 2, slot 9 of the GLONASS constellation.[9]

The initial plan was start launching the completely designed from scratch GLONASS-K2 satellites generation by 2014, however the plan was adjusted and the first launch has postponed to 2018[8][10]. The GLONASS-K2 satellites will have a 10-year design life and a clock stability of ~5-1x10-14. In addition to CDMA signals on L3, CDMA signals will also be transmitted on L1 and L2. The GLONASS-K satellites will transmit both legacy FDMA and CDMA signals[4].

As reported in [6], a modernized GLONASS-K satellite (GLONASS-KM) could transmit (no sooner than 2015) legacy FDMA signals on L1 and L2 and CDMA signals on L1, L2, and L3. It could also transmit CDMA signals on the GPS L5 frequency at 1176.45 MHz. GNSS integrity information could also be broadcast in the third civil signal and global differential ephemeris and time corrections.

Also being studied is an alternative to the present three-plane, equally spaced satellite constellation, which would also require the legacy FDMA signals be switched off.[5]

On February 8, 2016, a new GLONASS satellite was launched, intended to replace a 10-year old satellite that ceased operations last October in slot 17, orbital plane 3 of the GLONASS constellation.[11]

Another GLONASS-M satellite was launched sucessfully on May 29, 2016, despite some irregularities with its launcher. [12] The satellite became operational on June 27, 2016.[13]

Ground Segment

Fifteen new reference statiosn will be added, six of them outside the Russian territory, being the first one already placed in Antarctica.[14]

Also, the developments of both the GLONASS tracking capabilities as well as the steady increase in the number of GLONASS satellites, has had a positive influence on the accuracy of the GLONASS orbits and clocks. For instance, according to the GPSWorld article “Innovation: GPS, GLONASS, and More”[15] in 2008, the orbit quality, was at the 120-millimeter level (cross-track), which was improved significantly to the 85-millimeter level by the end of 2009.

Aiming to improve the interoperability with other GNSS systems, GLONASS coordinate system has been tied to the International Terrestrial Reference System (ITR), an international standard. The ephemeris information implementing the PZ-90.11 reference system has been implemented on all operational GLONASS satellites starting from 3:00 pm on December 31, 2013[16]. From this time on, the satellites are broadcasting in the PZ-90.11. This ECEF reference frame is an updated version of PZ-90, closest to the ITRF2008.

On March 6th, 2017, a new GLONASS station was officially commissioned in South Africa. That station will monitor GLONASS and GPS satellites’ navigation signals, measurements of current navigation parameters of their travel, and receipt of navigation messages from the satellites.[17]

User Segment

Although the GLONASS constellation is nearing global coverage, its commercialization, especially development of the user segment, has been lacking compared to the U.S. GPS system.[18] To improve the situation, the Russian government has been actively promoting GLONASS for civilian use. According to the Decree of the Government of Russian Federation “About use of GLONASS in technical system and transport vehicles”, August 25 2008, N 641, [19] GLONASS devices should be used in:

  • All spacecraft and separate components of them;
  • All civilian and experimental aircraft;
  • All river- and see-going vessels;
  • All railway and road vehicles for cargo- and passenger transportation;
  • All vehicles for transport of dangerous payload;
  • All surveying and map-making equipment;
  • All devices for time synchronization;

GLONASS will be used for road tax collection and roadside assistance. Vehicles sold in Russian Federation (starting from 2013) will feature a tracking system (known as ERA-GLONASS project) that will act as a black box device with the capability of alerting Emergency Centers in the event of an accident providing the precise position of the vehicle in question. This is expected to reduce emergency arrivel times by 30% on average. Please refer to [20] for further information.

Notes

References

  1. ^ Federal Task Program on the Global Navigation System
  2. ^ Munich Summit Charts Progress of GPS, GLONASS, Galileo, Beidou GNSSes, InsideGNSS, March 2012
  3. ^ Russia’s First GLONASS-K In Orbit, CDMA Signals Coming, insideGNSS
  4. ^ a b GLONASS Status and Modernization
  5. ^ a b [to http://gpsworld.com/ GLONASS Update Delves into Constellation Details, GPSworld]
  6. ^ a b GLONASS: The Once and Future GNSS, InsideGNSS
  7. ^ [2nd GLONASS-K1 Finally Reaches Space], Inside GNSS, December 2, 2014
  8. ^ a b GLONASS-K1 to Replace an Existing GLONASS-M in Six Months, GPS World, December 15, 2014
  9. ^ First GLONASS-K Satellite Enters Service
  10. ^ First Launch of GLONASS-K2 Satellite Planned for 2018, GPS World, April 2, 2015
  11. ^ Russia Launches First GLONASS-M in More Than a Year
  12. ^ New GLONASS-M Survives Slight Glitch to Reach Orbit
  13. ^ Recently Launched GLONASS-M Becomes Operational
  14. ^ GLONASS Up to Date and Out of State, GPSWorld
  15. ^ Innovation: GPS, GLONASS, and More, GPSWorld
  16. ^ The transition to using the terrestrial geocentric coordinate system PZ-90.11 in operating GLONASS system has been implemented, Russian Federal Space Agency, Information-analytical centre, 4 April 2014
  17. ^ GLONASS ground station goes live in South Africa
  18. ^ GLONASS on Wikipedia
  19. ^ FinNode-Services to Russian GLONASS Position system, FINPRO
  20. ^ NIS-GLONASS, ERA project
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