UPSC Prelims 2025 Q94: Science & Technology – Space Technology & Astronomy
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
Answer: (d) I and II only
Explanation
GPS-Aided Geo Augmented Navigation (GAGAN)
GAGAN was developed by ISRO and the Airports Authority of India.
It corrects GPS signals using ground stations and geostationary satellites.
| Statement | Verdict | Fact |
|---|---|---|
| I. It is designed to provide additional accuracy and integrity | Correct | Its basic purpose |
| II. It will allow more uniform and high quality air traffic management | Correct | Gives seamless navigation over Indian airspace |
| III. It will provide benefits only in aviation but not in other modes of transportation | Incorrect | It also helps railways, shipping, roads, surveying, farming and fishing |
Key facts:
| Feature | Detail |
|---|---|
| Type | Satellite-Based Augmentation System |
| Similar systems | WAAS (US), EGNOS (Europe), MSAS (Japan) |
| Certified | For precision approach in 2015 |
| Different from | NavIC, India's own navigation satellite system |
Answer: (d) I and II only.
Why each option is right or wrong
- (a) Incorrect. Statement III is false; benefits are not limited to aviation.
- (b) Incorrect. Statement III is false, and statement I is true.
- (c) Incorrect. Statement II is also true: it improves air traffic management.
- (d) CORRECT. GAGAN gives accuracy and integrity and better air traffic management.
Key point
GAGAN (ISRO and AAI): satellite-based augmentation of GPS for accuracy and integrity; aids aviation, railways, shipping and more; distinct from NavIC.
Remember
GAGAN = GPS correction by ISRO and AAI, for all transport.
Common mistakes
- Accepting 'only in aviation'; other transport modes benefit too.
- Confusing GAGAN (augments GPS) with NavIC (India's own satellites).
- Forgetting the joint developers: ISRO and the Airports Authority of India.
Exam tip
'Only ... but not ...' in a technology statement is nearly always false.
Sources
- Indian Space Research Organisation — GAGAN (GPS Aided Geo Augmented Navigation)
- Airports Authority of India — GAGAN programme