QUESTION 11
GS3
12.5 marks
What do you understand by ‘Standard Positioning Systems’ and ‘Precision Positioning Systems’ in the GPS era? Discuss the advantages India perceives from its ambitious IRNSS programme employing just seven satellites.
WRITE IN
9 min
200 words
What the examiner wants
Explain standard and precise positioning services and discuss what India gains from IRNSS.
What + DiscussExplain the different sides of the issue, use evidence, and finish with a balanced view.
Demand-wise check
- 1SPS: open civilian signal (GPS C/A code), lower accuracy, free for all≈35 words
- 2PPS: encrypted military signal (GPS P(Y) code), higher accuracy, restricted≈35 words
- 3IRNSS/NavIC: 7 satellites (3 GEO, 4 GSO) covering India and 1,500 km around; SPS and Restricted Service≈35 words
- 4Advantages: strategic autonomy (no denial as in Kargil 1999), defence, disaster, fishing, transport, mobiles; issues: atomic clock failures, NVS-02 orbit problem (2025)≈35 words
Open in about 30 words and close in about 30.
Answer plan
Define SPS and PPSIRNSS designAdvantagesChallenges
Where marks usually go
- Mixing SPS/PPS definitions
- Not explaining why only seven satellites suffice (regional system)
Draw this
- Diagram: 3 GEO + 4 GSO satellites and the coverage zone
Value addition
- ExampleDuring the 1999 Kargil war, India was reportedly denied GPS data, driving the push for an indigenous system.1999
- DataNavIC offers position accuracy better than 20 m over India and a 1,500 km surrounding region.ISRO
Next: plan for one minute, write it in 9 minutes, then get it checked.