Context: Indian Space Research Organisation (ISRO) successfully launched NVS-01 (a second-generation navigation satellite) on board the Geosynchronous Launch Vehicle from the Satish Dhawan Space Centre, Sriharikota, Andhra Pradesh.
What is new in the second-generation NavIC satellite?
- NVS-01 is the first of the second-generation navigation satellites designed to sustain and augment the NavIC constellation with enhanced features. The 2232 kg satellite carries navigation payloads L1, L5, and S bands and an indigenously developed rubidium atomic clock to determine date and location.
- L1 signals for better use in wearable devices: The second-generation satellites will send signals in a third frequency, L1, besides the L5 and S frequency signals that the existing satellites provide, increasing interoperability with other satellite-based navigation systems.
- NavIC system operates in the L5 band, which is a protected frequency specifically assigned to the Indian system. This dedicated frequency enhances the system’s robustness and ensures minimal interference from other signals.
- NVS-1 incorporates L1 band signalsadditionally to widen the services.
- The L1 frequency is among the most commonly used in the Global Positioning System (GPS) and will increase the use of the regional navigation system in wearable devices and personal trackers that use low-power, single-frequency chips.
- Atomic Clock: The satellite will have a Rubidium atomic clock onboard, indigenously developed by Space Application Centre-Ahmedabad. Satellite-based positioning systems determine the location of objects by accurately measuring the time it takes for a signal to travel to and back from it using the atomic clocks on board.
- Longer mission life: The second-generation satellites will also have a longer mission life of more than 12 years. The existing satellites have a mission life of 10 years.
- Navigation with Indian Constellation (NavIC), earlier known as Indian Regional Navigation Satellite System, is a satellite navigation system developed by the Indian Space Research Organisation (ISRO).
- To provide independent satellite navigation services to the Indian region, reducing dependence on other global navigation systems like the Global Positioning System (GPS) or the Russian GLONASS.
- To enhance the accuracy and reliability of positioning and timing services in various sectors, including transportation, disaster management, surveying, and agriculture.
- NavIC consists of a constellation of seven satellites in geostationary and geosynchronous orbits around the Earth, namely, IRNSS-1A, IRNSS-1B, IRNSS-1C, IRNSS-1D, IRNSS-1E, IRNSS-1F, and IRNSS-1G.
- NVS-01 will replace IRNSS-1G.
- It is designed to provide positioning, navigation, and timing services to users across India and the region extending up to 1,500 km around the country, with position accuracy of better than 20 meters, and timing accuracy of better than 50 nanoseconds.
NavIC offers two types of services:
- Standard Positioning Service (SPS): Available to all users and provides positioning accuracy of around 20 meters throughout the Indian region and within the primary service area.
- Restricted Service (RS): Encrypted service primarily intended for authorised users such as the military, government agencies, and other security-sensitive applications. It provides higher accuracy and additional features compared to the SPS.
- Terrestrial, aerial, and marine navigation
- Location-based services in mobile devices and marine fisheries
- Disaster management
- Vehicle tracking and fleet management
- Precise timing
- Mapping and geodetic data capture
- Terrestrial navigation aid for hikers and travellers
- Visual and voice navigation for drivers
- Precision agriculture
Advantages of having a regional navigation system:
- NavIC provides coverage over the Indian landmass and up to a radius of 1,500 km around it. Unlike GPS, NavIC uses satellites in high geo-stationery orbit — the satellites move at a constant speed relative to Earth, so they are always looking over the same region on Earth.
- NavIC signals come to India at a 90-degree angle, making it easier for them to reach devices located even in hard-to-reach areas like congested areas, dense forests, or mountains. GPS signals are received over India at an angle.
- With the use of NavIC picking up, the government has been looking at the possibility of increasing the coverage area of the system.
- Work is underway to set up ground stations in Japan, France, and Russia.
- Once fully operational — with ground stations outside India for better triangulation of signals — NavIC open signals will be accurate up to 5 metres and restricted signals will be even more accurate.
Satellite navigation systems of other countries:
- There are four global satellite-based navigation systems.
- United States: Global Position System (GPS)
- Russia: GLONASS
- China: BeiDou
- European Union: Galileo
Japan has a four-satellite regional navigation system (Quasi-Zenith Satellite System).