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.
● Tracked since June 27, 2026 · last seen July 01, 2026 · updates as the daily brief publishes