GPS Aided GEO Augmented Navigation (GAGAN)

Author: Tianjiang Shuo

Source: Feng Songjiang et al. (2021), "Analysis of Indian Space Power Development and Strategic Priorities"

Website: https://cislunarspace.cn

Definition

GPS Aided GEO Augmented Navigation (GAGAN) is a Satellite-Based Augmentation System (SBAS) developed by India to correct and enhance the civil signals of the U.S. GPS navigation satellites. GAGAN can improve GPS positioning accuracy from the original 10--15 meters to approximately 1 meter, significantly enhancing navigation and positioning performance over India and its surrounding regions.

Technical Specifications

ParameterValue
GPS raw accuracy10--15 meters
GAGAN augmented accuracyApproximately 1 meter
Coverage areaIndian mainland and surrounding regions
System typeSatellite-Based Augmentation System (SBAS)

System Components

The GAGAN system consists of the following components:

  • Ground reference station network: Collects GPS signals and computes error correction data
  • Ground master control station: Processes error data and generates augmentation messages
  • Geostationary satellites: Relay augmented signals to users
  • User equipment: Receives augmented signals and provides high-precision positioning

Application Scenarios

GAGAN is primarily used for:

  • Civil aviation: Provides precision approach support for aircraft takeoff, landing, and en-route flight
  • Ground transportation: Improves vehicle navigation and traffic management accuracy
  • Precision agriculture: Supports automated driving and precision operations of agricultural machinery
  • Surveying and geospatial information: Provides high-precision positioning benchmarks

Relationship with IRNSS

GAGAN relies on the GPS system and does not have independent navigation capability. India's indigenous independent navigation system is the Indian Regional Navigation Satellite System (IRNSS). Together, they form India's satellite navigation framework.

References

  • Feng Songjiang, Chang Zhuang, Wang Qian. Analysis of Indian Space Power Development and Strategic Priorities [J]. 2021. (in Chinese)