Why is Indian Regional Navigational Satellite System (IRNSS) needed ? How does it help in navigation ?
Approach · directive: “why / how”
What it asks · Give the reasons India built its own regional navigation system and explain how its satellites and ground network deliver position and timing to users.
The question has 2 parts — answer each
- Why IRNSS is needed: the strategic, service and self-reliance reasons for an indigenous regional system
- How it helps in navigation: the constellation, signals and services that deliver position and timing to users
Open with · IRNSS, operationally called NavIC, is India's own regional satellite navigation system, built to reduce dependence on foreign global systems.
Cover
- Need: strategic autonomy, since foreign systems such as GPS and GLONASS are controlled by others and can be degraded or denied; assured signals matter for defence, disaster response and critical services.
- Regional design: seven satellites, three in geostationary and four in inclined geosynchronous orbit, keep India and about 1,500 km beyond its boundary in continuous view of the system.
- Accuracy: designed to give position accuracy of better than 20 m over India and the neighbouring region, meeting civil and strategic needs.
- How it helps: satellites broadcast time-stamped signals from atomic clocks; receivers use delays from at least four satellites to fix position and time, while ground stations monitor orbits and clocks.
- Two services: an open Standard Positioning Service for all users and an encrypted Restricted Service for authorised users such as the armed forces.
- Uses: road, air and marine navigation, fishermen's safety, vehicle tracking, mapping and surveying, precise timing and disaster alerts; adoption needs NavIC-enabled chipsets in phones and devices.
- Limit: being regional, it complements rather than replaces GPS; multi-constellation receivers combine both for reliability.
Close with · IRNSS gives India assured, independent navigation; its real value will depend on wide chipset adoption and use alongside global systems.
Question: UPSC's CS (Main) 2018, GS Paper I — paper ↗. Approach: Minimalist IAS, checked 30 Sept 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer · 225 words (UPSC limit 150) · Minimalist IAS
IRNSS, operationally named NavIC, is India's own regional satellite navigation system, built by ISRO for assured position and timing over India and its neighbourhood.
Why India needed it
- Strategic autonomy: foreign systems such as GPS and GLONASS are controlled by other governments and can be degraded or denied in a crisis; assured signals matter for defence.
- Critical services: disaster response, aviation, shipping and telecom timing cannot rest on a signal India does not control.
- Regional focus: continuous coverage over India and about 1,500 km beyond its boundary, plus self-reliance in space technology and indigenous chipsets.
How it helps in navigation
- Constellation: seven satellites, three in geostationary and four in inclined geosynchronous orbit, so several are always high in India's sky.
- Working: satellites broadcast time-stamped signals from atomic clocks; a receiver uses the delays from at least four satellites to fix position and time, while ground stations monitor orbits and clocks.
- Accuracy: designed for position accuracy better than 20 m over the primary service area.
- Two services: an open Standard Positioning Service for civilian users and an encrypted Restricted Service for authorised users such as the armed forces.
- Uses: road, marine and air navigation, fishermen's safety alerts, surveying, precise timing and disaster warnings.
IRNSS gives India an independent, assured navigation backbone; its full value will come from NavIC-enabled devices and use alongside global constellations for reliability.
Written by Minimalist IAS from facts checked at source (how we verify) — a little fuller than exam length, so every part of the question is covered; in the hall, keep the structure and trim the detail. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.