Question 3 from UPSC CSE 2025 - S&T

Question

GPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation. Which of the following statements is/are correct in respect of GAGAN?
I. It is designed to provide additional accuracy and integrity.
II. It will allow more uniform and high quality air traffic management.
III. It will provide benefits only in aviation but not in other modes of transportation.
Select the correct answer using the code given below.

Accepted Answer

Correct Option: D. I and II only

Strategy: The focus is on what GAGAN enhances — statements about 'additional accuracy and integrity' and 'high quality air traffic management' directly match the technical objectives of such augmentation systems used in aviation. Statement III, limiting benefits only to aviation, can be eliminated since advanced navigation systems have recognized multi-sectoral applications. Thus, select statements I and II as correct.

Key Info: GAGAN (GPS Aided GEO Augmented Navigation) is India's Satellite Based Augmentation System (SBAS), developed by ISRO in collaboration with the Airports Authority of India (AAI). Its primary purpose is to augment the accuracy, integrity, and availability of GPS signals, particularly to meet safety-of-life navigation requirements in civil aviation. GAGAN achieves positioning accuracy improvements from ~20 meters (typical GPS) to 1–2 meters over the service region, and also provides timely integrity information vital for automated landing and enroute navigation. The system supports uniform and efficient air traffic management across India and neighboring airspace. Beyond aviation, GAGAN's enhanced navigational data supports a wide range of sectors, including maritime, road transport, railways, agriculture (precision farming), surveying, disaster management, and logistics, thus delivering advanced location services and operational efficiencies. Key GAGAN elements include reference stations, uplink stations, master control centers, and geostationary satellites broadcasting augmentation messages. This makes GAGAN the third such aviation-certified SBAS in the world, alongside the US WAAS and Europe's EGNOS.

Answer

Option A: I, II, and III

Answer

Option B: II and III only

Answer

Option C: I only