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.
- (a) I, II and III
- (b) II and III only
- (c) I only
- (d) I and II only ✓ UPSC's answer
Why the answer is (d)
• GAGAN, developed jointly by ISRO and the Airports Authority of India, is a satellite-based augmentation system that corrects GPS signals using Indian reference stations and geostationary satellites (GSAT-8, -10, -15).
• Statement I is correct: the augmentation improves positional accuracy to about 1–3 m and adds integrity — a guarantee that the signal can be trusted for safety-critical use.
• Statement II is correct: certified for approach and landing (APV-1/LPV), GAGAN lets aircraft fly precise, uniform procedures and allows more efficient, high-quality air-traffic management across Indian airspace.
• Statement III is wrong: GAGAN also serves railways (train tracking), road transport, maritime navigation, agriculture, surveying and disaster management — it is not aviation-only.
• Hence I and II only, option (d).
Why the other options are wrong
- (a) I, II and III
- Statement III is wrong: GAGAN benefits many sectors beyond aviation.
- (b) II and III only
- Statement III is wrong and statement I is correct.
- (c) I only
- Statement II on air traffic management is also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2025, held on 25 May 2025. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.