Ans. To satisfy the positioning, navigation, and timing needs of India, the Indian Space Research Organisation (ISRO) has developed a regional navigation satellite system known as Navigation with Indian Constellation (NavIC). Previously known as the Indian Regional Navigation Satellite System (IRNSS), NavIC is designed with a seven-satellite constellation and a network of ground stations that operate continuously. Of these, three satellites are placed in geostationary orbit, while the remaining four are in inclined geosynchronous orbit.

Genesis of NavIC: Lessons from the Past

The need for an indigenous satellite navigation system was realized in 1999 after the Kargil War, when India’s military was unable to access the American Global Positioning System (GPS) in the battle zone.
This led to the conception of the IRNSS, with the aim of developing an indigenous seven-satellite constellation that would cater to both defence and civilian needs.
The first satellite, IRNSS-1A, was launched on July 1, 2013, with subsequent launches of IRNSS-1B, 1C, 1D, 1E, 1F, and 1G.
On April 28, 2016, ISRO announced the successful launch of IRNSS-1G, marking the completion of the IRNSS constellation.

Challenges in Implementation

Since mid-2016, multiple navigation satellites, including ISRO’s IRNSS and the European Space Agency’s (ESA’s) Galileo Global Navigation Satellite System (GNSS), have reported failures in rubidium atomic clocks.
Each IRNSS satellite is equipped with three atomic clocks, essential for precise navigation and timing services.
As of 2025, only four IRNSS satellites are reported to be operational: IRNSS-1B, 1F, 1I (which replaced 1A after the launch failure of 1H), and 1J (which replaced the partially failed 1G).

Strategic Importance of NavIC

1. Dual Services for Civilian and Defence Applications

NavIC provides two distinct services:
- Standard Positioning Service (SPS): Available for general and commercial use.
- Restricted Service (RS): Meant exclusively for strategic applications and defence forces.

2. Enhanced Positioning Accuracy and Coverage

NavIC offers positioning data with an accuracy of better than 20 metres in all weather conditions.
The system provides coverage over India and a surrounding region of approximately 1,500 km, ensuring reliable navigation for both civilian and military users.

3. Ensuring Technological Self-Reliance and Security

Despite the existence of global navigation systems such as GPS (US), GLONASS (Russia), Galileo (Europe), Beidou (China), and QZSS (Japan), India developed NavIC to ensure independent and uninterrupted access to positioning data, particularly for strategic purposes.
Dependence on foreign navigation systems poses a risk of restricted access during critical situations, as seen during the Kargil War.
An indigenous system like NavIC eliminates vulnerabilities related to external control, thereby enhancing India’s national security and strategic autonomy.

4. Applications Across Sectors

Defence: Precision targeting, secure military communications, and real-time troop movement tracking.
Disaster Management: Early warning systems for cyclones, earthquakes, and other natural calamities.
Aviation & Maritime Navigation: Seamless navigation for civilian and military aircraft and ships.
Agriculture & Fisheries: Precision farming and tracking for fishing vessels.
Urban Mobility & Transportation: Integration with vehicle tracking systems and logistics.

NavIC represents a significant step toward self-reliance in satellite navigation, offering two key services: Standard Positioning Service (SPS) for civilians and Restricted Service (RS) for strategic users. Its accuracy of better than 20 metres ensures reliable positioning and navigation across India and surrounding regions. To maximize its utility, ISRO must integrate NavIC with general positioning service providers such as mobile phone manufacturers and automobile industries, making it widely accessible to users in the Indian subcontinent and beyond.

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