Beyond the sky: India’s Gagan now finds uses in other fields like marine navigation
India's GAGAN (GPS Aided GEO Augmented Navigation) system, originally developed for civil aviation, is being actively applied in marine navigation, telecommu...
What Happened
- India's GAGAN (GPS Aided GEO Augmented Navigation) system, originally developed for civil aviation, is being actively applied in marine navigation, telecommunications, geodesy, and disaster management.
- GAGAN holds the distinction of being the first Satellite-Based Augmentation System (SBAS) in the world certified for operations in the equatorial region, a technically challenging environment due to ionospheric signal disturbances near the equator.
- In June 2026, India achieved a further aviation milestone: the Directorate General of Civil Aviation (DGCA) successfully conducted India's first satellite-based precision landing approach on a commercial aircraft (an IndiGo Airbus A320) using GAGAN at Maharana Pratap Airport, Udaipur.
- GAGAN augments GPS signals, improving their accuracy for the Indian Flight Information Region (FIR) from approximately 20 metres to sub-1 metre precision, enabling applications in sectors where high positional accuracy is safety-critical.
Static Topic Bridges
GAGAN: GPS Aided GEO Augmented Navigation
GAGAN is a Satellite-Based Augmentation System (SBAS) jointly developed by the Indian Space Research Organisation (ISRO) and the Airports Authority of India (AAI). Unlike an independent navigation satellite system, GAGAN does not generate its own positioning signals; instead, it receives GPS signals and, using a network of ground reference stations across India, corrects errors caused by ionospheric disturbances, atmospheric delays, and satellite clock drift before retransmitting the corrected signals via geostationary satellites. This correction improves GPS accuracy from the standard 20-metre range to sub-1-metre precision.
- Developed jointly by ISRO (space segment) and AAI (ground segment and operational authority).
- Certified by DGCA for en-route operations (RNP 0.1) on 30 December 2013.
- Certified for precision approach services (APV 1 — Approach with Vertical Guidance, Level 1) on 21 April 2015.
- APV1-certified signals broadcast since 19 May 2015.
- Service area covers the Indian Flight Information Region (FIR) with capacity to expand to neighbouring FIRs.
- Third SBAS in the world to achieve APV1 certification; first to achieve it in the equatorial region.
Connection to this news: The equatorial certification is significant because ionospheric signal disturbances are most severe near the equator, making SBAS operation technically harder here than in mid-latitudes where US (WAAS), European (EGNOS), and Japanese (MSAS) systems operate.
Satellite-Based Augmentation Systems (SBAS) — Global Context
SBAS is a category of civil aviation navigation technology that augments global navigation satellite systems (GNSS) to meet aviation's demanding accuracy, integrity, continuity, and availability requirements. Major SBAS systems globally include: WAAS (Wide Area Augmentation System, USA), EGNOS (European Geostationary Navigation Overlay Service, Europe), MSAS (Multi-functional Satellite Augmentation System, Japan), and GAGAN (India). GAGAN was the fourth SBAS to become operational globally and the first to operate over the equatorial belt.
- SBAS systems are required for instrument approach procedures in civil aviation.
- Four operational SBAS globally: WAAS (USA), EGNOS (Europe), MSAS (Japan), GAGAN (India).
- Equatorial ionospheric disturbances (caused by the equatorial ionisation anomaly) make signal correction especially complex in India's latitude band.
- GAGAN's success demonstrated that SBAS technology can be adapted for equatorial environments, opening the door for similar systems in Southeast Asia and Africa.
Connection to this news: The expansion of GAGAN into marine navigation uses the same correction signal that was originally validated for aviation — demonstrating dual-use technology value from a single national investment.
GAGAN vs. NavIC (IRNSS) — India's Two Navigation Systems
India operates two complementary satellite navigation projects with distinct architectures and purposes. NavIC (Navigation with Indian Constellation), also called IRNSS (Indian Regional Navigation Satellite System), is India's fully independent satellite navigation system — a constellation of 7 satellites that generates its own positioning signals without relying on GPS, covering India and a region extending up to 1,500 km from its boundary. GAGAN, by contrast, is an augmentation overlay — it cannot function without the underlying GPS signals it corrects. NavIC provides strategic independence while GAGAN provides precision accuracy for safety-of-life aviation (and now marine) applications using existing GPS infrastructure.
- NavIC: 7-satellite constellation; independent of GPS; primary service area India + 1,500 km radius; developed entirely by ISRO.
- GAGAN: SBAS overlay; depends on GPS; corrects signals for Indian FIR; developed by ISRO + AAI jointly.
- NavIC is used in defence, fisheries (coastal vessels), and is being integrated into smartphones.
- GAGAN is used for civil aviation precision approaches and is now being extended to marine navigation, telecom, and disaster management.
- Both systems are expressions of India's "Atmanirbhar Bharat" in space-based navigation.
Connection to this news: The expansion of GAGAN into marine and disaster management domains demonstrates the multiplier effect of investments in both systems — the same infrastructure that serves aviation safety is now generating value across multiple sectors.
Marine Navigation and Satellite-Based Positioning
Marine navigation has historically relied on terrestrial radio navigation (LORAN), coastal radar, and later GPS. Satellite-augmented navigation (SBAS) provides a qualitative improvement for maritime applications: lane-precise positioning in narrow channels, port approach, and coastal zone management. For disaster management, accurate real-time positioning of vessels, aircraft, and ground assets is critical for search-and-rescue coordination. GAGAN's extension to maritime use aligns with India's Blue Economy and SAGAR (Security and Growth for All in the Region) strategy.
- India's coastline extends approximately 7,516 km, among the longest in Asia.
- Satellite-based positioning improves safety in narrow straits, estuaries, and during low-visibility conditions.
- GAGAN signals are freely accessible — no user fees — making them available to all maritime operators.
- Disaster Management: accurate real-time location data from GAGAN aids NDRF (National Disaster Response Force) and Coast Guard operations.
Connection to this news: The marine extension of GAGAN is a low-cost dividend from a national investment already made — the signal infrastructure is in place, and expanding its application to new sectors requires mainly software and receiver certification work.
Key Facts & Data
- GAGAN full form: GPS Aided GEO Augmented Navigation.
- Developed by: ISRO + Airports Authority of India (AAI).
- APV1 certification date: 21 April 2015 (by DGCA).
- First SBAS to be certified for the equatorial region.
- Third SBAS globally to achieve APV1 precision approach certification.
- Standard GPS accuracy: ~20 metres; GAGAN-corrected: sub-1 metre.
- India's first satellite-based precision landing on a commercial jet: IndiGo Airbus A320, Udaipur, June 2026.
- Other SBAS systems: WAAS (USA), EGNOS (Europe), MSAS (Japan).
- NavIC/IRNSS: India's independent navigation system; 7 satellites; not an augmentation system.
- GAGAN applications beyond aviation: marine navigation, telecommunications, geodesy, surveying, disaster management.