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The Indian Regional Navigational Satellite System (IRNSS) is a regional satellite navigation system owned by the Indian government. The system is being developed by [http://www.isro.org Indian Space Research Organization (ISRO)] .
The Indian Regional Navigational Satellite System (IRNSS) is a regional satellite navigation system owned by the Indian government. The system is being developed by Indian Space Research Organization (ISRO).
 
In April 2016, with the last launch of the constellation's satellite, IRNSS was renamed Navigation Indian Constellation (NAVIC) by India’s Prime Minister Narendra Modi.<ref> [http://gpsworld.com/with-irnss-1g-launch-india-completes-and-renames-its-navigation-constellation/ With IRNSS-1G launch, India completes and renames its navigation constellation]</ref>


==IRNSS Introduction==
==IRNSS Introduction==
Line 14: Line 16:




IRNSS will be an independent and autonomous regional navigation system aiming a service area of about 1500 kilometers around India. The system will be under complete Indian control, with the space segment, ground segment and user receivers all being built in India.<ref name="IRNSS_WIKI"> [http://en.wikipedia.org/wiki/Indian_Regional_Navigational_Satellite_System IRNSS in Wikipedia]</ref> It will have a range of applications including personal navigation.
IRNSS is an independent and autonomous regional navigation system aiming a service area of about 1500 kilometers around India. The system will be under complete Indian control, with the space segment, ground segment and user receivers all being built in India.<ref name="IRNSS_WIKI"> [http://en.wikipedia.org/wiki/Indian_Regional_Navigational_Satellite_System IRNSS in Wikipedia]</ref> It will have a range of applications including personal navigation.


==IRNSS Architecture==
==IRNSS Architecture==


IRNSS is planned to have 7 satellites complemented with the appropriate ground infrastructure<ref name="GAGAN_COSPAR">[http://www.oosa.unvienna.org/pdf/icg/2008/expert/2-3.pdf ''IRNSS and GAGAN status Presentation''] COSPAR Meeting, Montreal, July 2008</ref> as a minimum<ref name=IRNSS_ICD>[http://irnss.isro.gov.in/ IRNSS SIS ICD For SPS, Version 1.0], ISRO (Indian Space Research) Satellite Centre, Bangalore, June 2014</ref>.
IRNSS has 7 satellites complemented with the appropriate ground infrastructure as a minimum<ref name=IRNSS_ICD>[https://www.unoosa.org/pdf/icg/2013/icg-8/5.pdf Indian Regional Navigation Satellite System Program, Indian Space Research Organisation HQ]</ref>.
As it is traditional in GNSS systems, the architecture is described next in three different segments: the space segment, the ground segment and the user segment.
As it is traditional in GNSS systems, the architecture is described next in three different segments: the space segment, the ground segment and the user segment.


*The '''IRNSS Space Segment''': 3 of the 7 satellites are geostationary orbit (GEOs) and they will be located at 32.5º East, 83º East and 131.5º East longitude<ref name=IRNSS_ICD/>. There will be 4 geostationary satellites (GSO) in orbits of 24,000 km apogee and 250 km perigee inclined at 29 degrees. Two of the GSOs will cross the equator at 55º East and  the other two at 111.75º East (two satellites in each plane)<ref name=IRNSS_ICD/>.  The life span of the GEOs is 9.5 years and 11 years in the case of the GSOs.<ref name="GAGAN_COSPAR"/> The Constellation Design Considerations have been mainly:<ref name=IRNSS_B/>
*The '''IRNSS Space Segment''': 3 of the 7 satellites are geostationary orbit (GEOs) and they are located at 32.5º East, 83º East and 131.5º East longitude<ref name=IRNSS_ICD/>. There are 4 geostationary satellites (GSO) in orbits of 24,000 km apogee and 250 km perigee inclined at 29 degrees. Two of the GSOs cross the equator at 55º East and  the other two at 111.75º East (two satellites in each plane)<ref name=IRNSS_ICD/>.  The life span of the GEOs is 9.5 years and 11 years in the case of the GSOs.<ref>[https://www.jagranjosh.com/general-knowledge/irnss-1606397318-1 What is the Indian Regional Navigation Satellite System (IRNSS-NavIC)? in Jagran Josh website]</ref> The Constellation Design Considerations have been mainly:
** Minimizing the Maximum DOP
** Minimizing the Maximum DOP
** Minimum number of satellites  
** Minimum number of satellites  
Line 28: Line 30:
[[File:IRNSSArchitecture.PNG|IRNSS Architecture|thumb|300px]]
[[File:IRNSSArchitecture.PNG|IRNSS Architecture|thumb|300px]]


*The '''IRNSS Ground Segment''' will consist of:<ref name=IRNSS_B/>
*The '''IRNSS Ground Segment''' consists of:<ref name="ICD">[https://www.isro.gov.in/sites/default/files/irnss_sps_icd_version1.1-2017.pdf IRNSS SIGNAL IN SPACE ICD FOR STANDARD POSITIONING SERVICE v1.1]</ref>
**IRNSS Space Craft Control Centre (SCC)
**ISRO Navigation Centre
**IRNSS Navigation Centre (INC)
**IRNSS Spacecraft Control Facility
**IRNSS TTC & Uplinking Stations (IRTTC)
**IRNSS Range and Integrity Monitoring Stations
**IRNSS Range and Integrity Monitoring Stations (IRIMS)
**IRNSS Network Timing Centre
**IRNSS Timing Centre (IRNWT)
**IRNSS CDMA Ranging Stations
**IRNSS CDMA Ranging Stations (IRCDR)
**Laser Ranging Stations
**Laser Ranging Station (ILRS)
**Data Communication Network
**Data Communication Network (IRDCN)
The ground segment is in charge of estimating and predicting IRNSS satellites position, calculation of integrity, ionospheric and clock corrections and running the navigation software.
The SCC and the INC will be the core of the ground segment, and they are in charge of estimating and predicting IRNSS satellites position, calculation of integrity, ionospheric and clock corrections and running the navigation software.
 
*The '''IRNSS User segment''': the IRNSS user segment is made of the IRNSS receivers. They will be dual-frequency receivers (L5 and S band frequencies) or single frequency (L5 or S band frequency) with capability to receive ionospheric correction. They will be able to receive and process navigation data from other GNSS constellations and the seven IRNSS satellites will be continuously tracked by the user receiver. The user receiver will have a minimum gain G/T of -27 dB/K.<ref name=IRNSS_B>[http://www.oosa.unvienna.org/pdf/icg/providersforum/02/pres04.pdf ''IRNSS and GAGAN Status Presentation''] Second Meeting of the ICG Providers Forum, Vienna, Austria, February 2008</ref>


*The '''IRNSS User segment''': the IRNSS user segment is made of the IRNSS receivers. They will be dual-frequency receivers (L5 and S band frequencies) or single frequency (L5 or S band frequency) with capability to receive ionospheric correction. They will be able to receive and process navigation data from other GNSS constellations and the seven IRNSS satellites will be continuously tracked by the user receiver. The user receiver will have a minimum gain G/T of -27 dB/K.
==IRNSS Services and Performances==
==IRNSS Services and Performances==


There will be two kinds of services:<ref name="GAGAN_COSPAR"/>
There will be two kinds of services:<ref name="ICD"/>


*Special Positioning Service (SPS)
*Special Positioning Service (SPS)
*Precision Service (PS)
*Precision Service (PS)
[[File:IRNSS_IGP.PNG|IGP GRID to be used in IRNSS|thumb|160px]]
[[File:IRNSS_IGP.PNG|IGP GRID to be used in IRNSS|thumb|160px]]
Both services will be carried on L5 (1176.45 MHz) and S band (2492.08 MHz). The [[IRNSS_Signal_Plan|navigation signals]] would be transmitted in the S-band frequency (2–4 GHz) and broadcast through a phased array antenna to keep required coverage and signal strength.
Both services will be carried on L5 (1176.45 MHz) and S band (2492.028 MHz). The [[IRNSS_Signal_Plan|navigation signals]] would be transmitted in the S-band frequency and broadcast through a phased array antenna to keep required coverage and signal strength.


The data structure for SPS and PS is under study; it is being planned to take advantage of the fact that the number of satellites is reduced -7 instead of the 30 used in other constellations- to broadcast ionospheric corrections for a grid of 80 points to provide service to single frequency users. The clock, ephemeris, almanac data of the 7 IRNSS satellites will be transmitted with the same accuracy as in legacy GPS, GLONASS & Galileo.<ref>[http://www.oosa.unvienna.org/pdf/icg/2008/icg3/07.pdf ''GAGAN and IRNSS Status Presentation''] ICG-3 Meeting, Pasadena, United States of America, December 2008</ref>
The data structure for SPS and PS takes advantage of the fact that the number of satellites is reduced -7 instead of the 30 used in other constellations- to broadcast ionospheric corrections for a grid of 80 points to provide service to single frequency users. The clock, ephemeris, almanac data of the 7 IRNSS satellites are transmitted with the same accuracy as in legacy GPS, GLONASS & Galileo.


The Performances expected for the IRNSS system are: Position accuracy around 20 m over the Indian Ocean Region (1500 km around India) and less than 10 m accuracy over India and GSO adjacent countries.
The Performances expected for the IRNSS system are: Position accuracy around 20 m over the Indian Ocean Region (1500 km around India) and less than 10 m accuracy over India and GSO adjacent countries.<ref>[https://link.springer.com/article/10.1134/S2075108717020109  Vasudha, M.P., Raju, G. Comparative evaluation of IRNSS performance with special reference to positional accuracy. Gyroscopy Navig. 8, 136–149 (2017)]</ref>


==IRNSS Development==
==IRNSS Development==
Line 58: Line 58:
The Indian government approved the project in May 2006, with the intention of the system to be completed and implemented by 2015.  
The Indian government approved the project in May 2006, with the intention of the system to be completed and implemented by 2015.  


The first satellite of the proposed constellation was successfully launched on the 1st of July 2013<ref>[http://www.gpsworld.com/india-launches-first-navigation-satellite/ India Launches First Navigation Satellite, GPS World]</ref>. It is IRNSS-1A one of the three Geosynchronous satellites that will is compose the entire constellation<ref>[http://www.isro.org/satellites/irnss-1a.aspx?Search=IRNSS-1A IRNSS Navigation Satellites]</ref>. Despite the first launch was executed slightly later than the planned, at that time India has announced the deadline of 2015-2016 to launch the remaining six satellites<ref>[http://www.isro.org/pressrelease/scripts/pressreleasein.aspx?Jul02_2013 IRNSS Press Release, July 2, 2013]</ref>. As in the first launch the forthcoming will place in orbit only one satellite at a time. For that it is scheduled regular launches in every six months<ref>[http://tribune.com.pk/story/570847/india-to-launch-satellite-navigation-system/ India launches its first dedicated navigation satellite, The Express Tribune]</ref>.
The first satellite of the proposed constellation was successfully launched on the 1st of July 2013<ref>[http://www.gpsworld.com/india-launches-first-navigation-satellite/ India Launches First Navigation Satellite, GPS World]</ref>. It is IRNSS-1A one of the three Geosynchronous satellites that will is compose the entire constellation<ref>[https://www.isro.gov.in/irnss-programme IRNSS Navigation Satellites]</ref>. Despite the first launch was executed slightly later than the planned, at that time India has announced the deadline of 2015-2016 to launch the remaining six satellites<ref> IRNSS Press Release, July 2, 2013</ref>. As in the first launch the forthcoming will place in orbit only one satellite at a time. For that it is scheduled regular launches in every six months<ref>[http://tribune.com.pk/story/570847/india-to-launch-satellite-navigation-system/ India launches its first dedicated navigation satellite, The Express Tribune]</ref>.
As of 18 July 2013 the Indian Space Research Organisation (ISRO) announced that the satellite successfully reached its defined inclined geosynchronous orbit and that the verification tests would start one week after. Before that, in 23 July the German Aerospace Center was able to receive a signal transmitted in the L5 band from the IRSNSS-1A satellite. From the analysis of the received signal researchers from German Aerospace Center concluded that the signal structure is consistent with what was announced as [[IRNSS Signal Plan]] by ISRO<ref>[http://www.gpsworld.com/indian-regional-gnss-satellite-starts-signal-transmissions/ Indian Regional Navigation Satellite Starts Signal Transmissions, GPS World, 25 July 2013]</ref>.
As of 18 July 2013 the Indian Space Research Organisation (ISRO) announced that the satellite successfully reached its defined inclined geosynchronous orbit and that the verification tests would start one week after. Before that, in 23 July the German Aerospace Center was able to receive a signal transmitted in the L5 band from the IRSNSS-1A satellite. From the analysis of the received signal researchers from German Aerospace Center concluded that the signal structure is consistent with what was announced as [[IRNSS Signal Plan]] by ISRO<ref>[http://www.gpsworld.com/indian-regional-gnss-satellite-starts-signal-transmissions/ Indian Regional Navigation Satellite Starts Signal Transmissions, GPS World, 25 July 2013]</ref>.
On October 16, 2014, India’s Indian Space Research Organisation (ISRO) successfully launched its third navigation satellite IRNSS-1C abord a Polar Satellite Launch Vehicle (PSLV) rocket from Satish Dhawan Space Centre, Sriharikota.  
On October 16, 2014, India’s Indian Space Research Organisation (ISRO) successfully launched its third navigation satellite IRNSS-1C abord a Polar Satellite Launch Vehicle (PSLV) rocket from Satish Dhawan Space Centre, Sriharikota.  
The fourth IRNSS-1D satellite was successfully placed in orbit onboard the Polar Satellite Launch Vehicle (PSLV-C27), on March 28, 2015. The ISRO's Master Control Facility took over the control of the satellite and after that conducted several maneuvers in order to position the satellite in the geosynchronous orbit at 111.75 degrees East longitude with 30.5 deg inclination<ref>[http://www.insidegnss.com/node/4472 Indian Launches Fourth IRNSS Spacecraft, Inside GNSS, March 28, 2015]</ref>. The satellite reached its intended orbit slot on April 9th, 2015.<ref>[http://gpsworld.com/all-systems-go-with-a-spring-into-space/ The System: All Systems Go, with a Spring into Space]</ref>
The fourth IRNSS-1D satellite was successfully placed in orbit onboard the Polar Satellite Launch Vehicle (PSLV-C27), on March 28, 2015. The ISRO's Master Control Facility took over the control of the satellite and after that conducted several maneuvers in order to position the satellite in the geosynchronous orbit at 111.75 degrees East longitude with 30.5 deg inclination<ref>[https://insidegnss.com/indian-launches-fourth-irnss-spacecraft/ Indian Launches Fourth IRNSS Spacecraft, Inside GNSS, March 28, 2015]</ref>. The satellite reached its intended orbit slot on April 9th, 2015.<ref>[http://gpsworld.com/all-systems-go-with-a-spring-into-space/ The System: All Systems Go, with a Spring into Space]</ref><br>
 
The fifth satellite of the IRNSS constellation was launched on January 20, 2016. <ref>[http://gpsworld.com/indias-fifth-navigation-satellite-launched/ India’s fifth navigation satellite launched]</ref> That launch was closely followed by the 6th launch of a IRNSS satellite on March 10, 2016<ref>[https://insidegnss.com/india-successfully-launches-irnss-1f-into-orbit/ India Successfully Launches IRNSS 1F into Orbit]</ref>. The seventh and final satellite was launched on April 28, 2016 <ref>[https://insidegnss.com/india-completes-irnss-constellation/ India Completes IRNSS Constellation]</ref>.An eighth satellite was launched in 2018<ref>[https://www.isro.gov.in/Spacecraft/irnss-1i Department of Space, Indian Space Research Organisation website]</ref> to replace the failed IRNSS-1A.
 
In 2020 IRNSS was recognized as a component of IMO’s World Wide Radio Navigation Systems<ref>[https://insidegnss.com/indias-irnss-now-part-of-world-wide-radio-navigation-system/ Inside GNSS: India’s IRNSS Now Part of World Wide Radio Navigation System]</ref>, which enables merchant vessels to use IRNSS for obtaining position information.


==References==
==References==

Latest revision as of 05:53, 22 April 2021


IRNSSIRNSS
Title NAVIC
Edited by GMV
Level Basic
Year of Publication 2011
Logo GMV.png

The Indian Regional Navigational Satellite System (IRNSS) is a regional satellite navigation system owned by the Indian government. The system is being developed by Indian Space Research Organization (ISRO).

In April 2016, with the last launch of the constellation's satellite, IRNSS was renamed Navigation Indian Constellation (NAVIC) by India’s Prime Minister Narendra Modi.[1]

IRNSS Introduction

ISRO logo


IRNSS is an independent and autonomous regional navigation system aiming a service area of about 1500 kilometers around India. The system will be under complete Indian control, with the space segment, ground segment and user receivers all being built in India.[2] It will have a range of applications including personal navigation.

IRNSS Architecture

IRNSS has 7 satellites complemented with the appropriate ground infrastructure as a minimum[3]. As it is traditional in GNSS systems, the architecture is described next in three different segments: the space segment, the ground segment and the user segment.

  • The IRNSS Space Segment: 3 of the 7 satellites are geostationary orbit (GEOs) and they are located at 32.5º East, 83º East and 131.5º East longitude[3]. There are 4 geostationary satellites (GSO) in orbits of 24,000 km apogee and 250 km perigee inclined at 29 degrees. Two of the GSOs cross the equator at 55º East and the other two at 111.75º East (two satellites in each plane)[3]. The life span of the GEOs is 9.5 years and 11 years in the case of the GSOs.[4] The Constellation Design Considerations have been mainly:
    • Minimizing the Maximum DOP
    • Minimum number of satellites
    • Orbital slots for India for a continuous visibility with the control stations
IRNSS Architecture
  • The IRNSS Ground Segment consists of:[5]
    • ISRO Navigation Centre
    • IRNSS Spacecraft Control Facility
    • IRNSS Range and Integrity Monitoring Stations
    • IRNSS Network Timing Centre
    • IRNSS CDMA Ranging Stations
    • Laser Ranging Stations
    • Data Communication Network

The ground segment is in charge of estimating and predicting IRNSS satellites position, calculation of integrity, ionospheric and clock corrections and running the navigation software.

  • The IRNSS User segment: the IRNSS user segment is made of the IRNSS receivers. They will be dual-frequency receivers (L5 and S band frequencies) or single frequency (L5 or S band frequency) with capability to receive ionospheric correction. They will be able to receive and process navigation data from other GNSS constellations and the seven IRNSS satellites will be continuously tracked by the user receiver. The user receiver will have a minimum gain G/T of -27 dB/K.

IRNSS Services and Performances

There will be two kinds of services:[5]

  • Special Positioning Service (SPS)
  • Precision Service (PS)
IGP GRID to be used in IRNSS

Both services will be carried on L5 (1176.45 MHz) and S band (2492.028 MHz). The navigation signals would be transmitted in the S-band frequency and broadcast through a phased array antenna to keep required coverage and signal strength.

The data structure for SPS and PS takes advantage of the fact that the number of satellites is reduced -7 instead of the 30 used in other constellations- to broadcast ionospheric corrections for a grid of 80 points to provide service to single frequency users. The clock, ephemeris, almanac data of the 7 IRNSS satellites are transmitted with the same accuracy as in legacy GPS, GLONASS & Galileo.

The Performances expected for the IRNSS system are: Position accuracy around 20 m over the Indian Ocean Region (1500 km around India) and less than 10 m accuracy over India and GSO adjacent countries.[6]

IRNSS Development

The Indian government approved the project in May 2006, with the intention of the system to be completed and implemented by 2015.

The first satellite of the proposed constellation was successfully launched on the 1st of July 2013[7]. It is IRNSS-1A one of the three Geosynchronous satellites that will is compose the entire constellation[8]. Despite the first launch was executed slightly later than the planned, at that time India has announced the deadline of 2015-2016 to launch the remaining six satellites[9]. As in the first launch the forthcoming will place in orbit only one satellite at a time. For that it is scheduled regular launches in every six months[10]. As of 18 July 2013 the Indian Space Research Organisation (ISRO) announced that the satellite successfully reached its defined inclined geosynchronous orbit and that the verification tests would start one week after. Before that, in 23 July the German Aerospace Center was able to receive a signal transmitted in the L5 band from the IRSNSS-1A satellite. From the analysis of the received signal researchers from German Aerospace Center concluded that the signal structure is consistent with what was announced as IRNSS Signal Plan by ISRO[11]. On October 16, 2014, India’s Indian Space Research Organisation (ISRO) successfully launched its third navigation satellite IRNSS-1C abord a Polar Satellite Launch Vehicle (PSLV) rocket from Satish Dhawan Space Centre, Sriharikota. The fourth IRNSS-1D satellite was successfully placed in orbit onboard the Polar Satellite Launch Vehicle (PSLV-C27), on March 28, 2015. The ISRO's Master Control Facility took over the control of the satellite and after that conducted several maneuvers in order to position the satellite in the geosynchronous orbit at 111.75 degrees East longitude with 30.5 deg inclination[12]. The satellite reached its intended orbit slot on April 9th, 2015.[13]

The fifth satellite of the IRNSS constellation was launched on January 20, 2016. [14] That launch was closely followed by the 6th launch of a IRNSS satellite on March 10, 2016[15]. The seventh and final satellite was launched on April 28, 2016 [16].An eighth satellite was launched in 2018[17] to replace the failed IRNSS-1A.

In 2020 IRNSS was recognized as a component of IMO’s World Wide Radio Navigation Systems[18], which enables merchant vessels to use IRNSS for obtaining position information.

References