Tuesday, 1 July 2025

Navigation with Indian Constellation (NavIC)

Technology helped us take the enemy head on and win the Kargil by the laser guided precision bombs and heavy artillery. Data about enemy troop was required and Indian military sought GPS data. The space-based navigation system would have provided vital information but USA denied it to India. Our fighter Pilots flew real-time missions with hand-held GPS and use of airpower was one of the excellent features of the Kargil operations.

To avoid heavy reliance on GPS technology, ISRO established a regional navigation satellite system called Navigation with Indian Constellation (NavIC) earlier known as Indian Regional Navigation Satellite System (IRNSS). The project was approved in 2006 by the Indian government, the launch of the first NavIC satellite was in 2013 and completion of the NavIC constellation was in 2016.  NavIC became operational in 2017, offering Standard Positioning Service (SPS) for civilian users and Restricted Service (RS) for authorized / strategic users, with position accuracy better than 20 meters in its primary service area. And a year later NavIC was integrated in mobile devices to promote widespread adoption and usage. Continuous improvements and the addition of new satellites ensure NavIC remains a robust and reliable regional navigation system, supporting diverse applications in India and neighboring areas.

GPS (Global Positioning System) is a satellite-based navigation system developed and maintained by the United States Department of Defense since 1973. It consists of a constellation of at least 24 satellites orbiting Earth. GPS is widely used worldwide in civilian, commercial, and military operations, providing position accuracy within a few meters. GPS has been a Global pioneer for decades whereas NavIC has been an emerging Indigenous technology in recent times. NavIC is designed with a constellation of 7 satellites and a network of ground stations operating 24 x 7. The coverage area includes India and a region up to 1500 km beyond Indian boundary. NavIC signals are designed to provide user position accuracy better than 20m and timing accuracy better than 50ns.

GPS offers a global solution, whereas NavIC is specially designed for regional applications within India, focusing on domestic needs, such as public safety and disaster management, which aligns with India’s strategic objectives.
 
https://www.isro.gov.in/SatelliteNavigationServices.html

NavIC, India’s regional navigation satellite system, focuses on applications particularly relevant to India and its neighboring regions. It is used for public vehicle tracking, improving safety standards in commercial transportation, and ensuring real-time alerts for emergencies, such as alerts for fishermen in distress at sea.. The technology is also used in disaster management efforts as it provides precise location data, which is crucial for assessing damage, coordinating rescue operations, and streamlining disaster response initiatives.

When India unleashed Operation Sindoor in May 2025, the world watched its advanced missiles, drones, and stealth assets. But one of the most decisive factors in the success of this coordinated military operation was invisible - orbiting silently above the subcontinent - NavIC, India’s indigenous satellite navigation system. India's use of NavIC during Operation Sindoor demonstrated several critical advantages:

- Independence from U.S. GPS: India could strike deep without relying on any foreign-owned navigation signals.

- Encrypted Military Channel prevented Pakistani jamming or spoofing during missile and drone missions

India’s vision for Navic includes hypersonic weapon integration for guiding future hypersonic glide vehicles. And Space command network for India’s Defence, Space, Intelligence and surveillance.

https://www.earlytimes.in/m/newsdet.aspx?q=175100

(NavIC maps are available, the free version helps location and directions but unlike say Google Maps, does not show vehicular traffic. I have not tried the paid version).

Saturday, 7 June 2025

Chenab Rail Bridge. World's highest railway arch bridge

Prime Minister Narendra Modi  inaugurated the Chenab Rail Bridge in Jammu and Kashmir on 6th June 2025, marking a major milestone in India’s railway infrastructure. It is the tallest railway arch bridge in the world. This event is also a significant development in enhancing rail connectivity in the region, especially between Jammu and Srinagar. It is:

The world’s highest railway arch bridge standing 359 metres above the Chenab River, it is designed as a steel arch bridge. Chenab Bridge with an overall length of 1315 m, an arch span of 467 m, and towering 359 m above the riverbed—making it taller than the Eiffel Tower and acclaimed as the world's highest arch railway bridge.

 

An engineering feat, built to endure extreme seismic activity and high wind speeds, the bridge represents a triumph of modern engineering in one of India’s most challenging terrains.

 

On connectivity, the bridge is a key component of the Udhampur-Srinagar-Baramulla Rail Link (USBRL) project. It will significantly reduce travel time between Katra and Srinagar to about three hours, via the Vande Bharat trains – as against the 67 hours by road.

After an extensive inspection of the newly constructed Chenab Bridge by senior officers from Railway Board, Northern Railway and Konkan Railway, a trial run of the eight-coach Mainline Electric Multiple Unit (MEMU) train was conducted on 5th June. This was on a 46-km-long electrified line section between Sangaldan in Ramban district and Reasi at a speed of 40 kmph. The world’s highest railway bridge, in Jammu and Kashmir, marks a significant step towards commencing rail operations on the Reasi-Baramulla route in Kashmir. 

According to Afcons Infrastructure Limited, the top infrastructure company that constructed the bridge, one of the main and earliest challenges was access to the bridge location, to transport equipment and construction materials. Eventually, on the North side of the river bank, an 11-km road was constructed and a 12-km road on the South side. Further comments on the challenges faced can be read here:

https://www.thehindubusinessline.com/economy/logistics/chenab-bridge-construction-horses-mules-worlds-highest-railway-bridge/article69667650.ece

 

Other articles can be read here:

https://timesofindia.indiatimes.com/life-style/travel/news/jk-pm-narendra-modi-inaugurates-worlds-highest-railway-arch-today-chenab-bridge-in-8-points/articleshow/121667318.cms

https://www.business-standard.com/india-news/pm-modi-inaugurate-worlds-highest-chenab-rail-bridge-june-6-top-points-125060500273_1.html

 

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