The Indian Space Research Organisation (ISRO) and the Airports Authority of India (AAI) have developed GAGAN, a Satellite-Based Augmentation System (SBAS) aimed at improving the accuracy, availability, and reliability of GPS (Global Positioning System) signals for aviation and other modes of transportation. This system adheres to international standards and is compatible with other SBAS systems. GAGAN provides navigational support over a vast region, extending from Africa to Australia.
Prerequisites:
• Reliable and continuous access to GNSS signals for augmentation and coordination with GNSS providers if required (i.e. for SBAS Interoperatbility)
• Network to monitoring and reference stations to track GNSS signal errors
• Correction processing capability to calculate and correct errors
• Regulatory alignment with international standards (ICAO, IMO, ITU)
Cost:
LEO/Smallsat Augmentation
• Ballpark (CAPEX): USD 50–100M + OPEX USD 5-10M/yr
• Includes: design and development of CubeSat/smallsat augmentation payloads, limited constellation deployment, launch services, ground stations and control facilities, testing and integration, training and technology transfer, constellation operations, replenishment of short-lifespan satellites, cybersecurity, certification and compliance, staffing
Regional SBAS System
• Ballpark (CAPEX): USD 100–300M +OPEX USD 10–20M/yr
• Includes: development of ground-based augmentation infrastructure (reference stations, master control centres, uplink facilities), GEO augmentation payloads, certification with ICAO, international interoperability coordination, national R&D and training, continuous operations and monitoring, certification upkeep, cybersecurity, ICAO compliance, staff salaries, system upgrades
Timeframe:
LEO/Smallsat Augmentation
• Overall: 48–72 mo
• Phases: scoping/feasibility (12–18 mo), design/prototyping (12–18 mo), integration/testing (12–18 mo), launch/deployment (6–12 mo), operations (ongoing with OPEX)
Regional SBAS System
• Overall: 60–96 mo
• Phases: scoping & spectrum/ICAO alignment (12–18 mo), design/procurement (18–24 mo), infrastructure development/integration (24–36 mo), certification/testing (6–18 mo), operations (ongoing with OPEX)
Pros:
• Increased Accuracy - Improvement to even cm level positioning compared to standard GNSS signal
• Better Monitoring - Enhanced real-time awareness on GNSS data and its integrity
• Economic Benefits - Advanced services that require greater precision are enabled
Considerations:
• High Deployment Costs - Plan for substantial initial investment due to deployment expenses.
• Complex Integration Requirements - Coordinate closely with GNSS providers to manage complex integration, calibration, and alignment needs.