Global Navigation Satellite Systems (GNSS) – UPSC Revision Sheet

 

Global Navigation Satellite Systems (GNSS) –  UPSC Revision Sheet

1️⃣ GPS – United States

System: Global Positioning System

Country: United States

Key Facts

• Operational since 1995

• ~30 satellites

• Global coverage

• Operated by U.S. Space Force

Uses

• Navigation (aircraft, ships, vehicles)

• Smartphone location services

• Military guidance systems

• Timing for banking & telecom

UPSC Fact

• GPS is currently the global reference standard for timing and navigation.

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2️⃣ GLONASS – Russia

System: GLONASS

Country: Russia

Key Facts

• Fully operational since 1995

• ~24 satellites

• Global coverage

• Run by the Russian Aerospace Forces

Uses

• Military navigation

• Aviation

• Arctic region navigation

UPSC Fact

• GLONASS was the Soviet Union’s answer to GPS.

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3️⃣ Galileo – European Union

System: Galileo

Country/Organization: European Union

Key Facts

• Operational since 2016

• Planned 30 satellites

• Global coverage

• Operated by the European Union Agency for the Space Programme

Special Feature

• One of the most accurate civilian navigation systems.

UPSC Fact

• Galileo is fully civilian-controlled, unlike GPS or GLONASS.

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4️⃣ BeiDou – China

System: BeiDou Navigation Satellite System

Country: China

Key Facts

• Global system completed in 2020

• ~35 satellites

• Global coverage

• Developed by the China National Space Administration

Special Feature

• Provides short message communication services.

UPSC Fact

• BeiDou has the largest satellite constellation among GNSS systems.

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5️⃣ NavIC – India

System: NavIC

Country: India

Developed by: Indian Space Research Organisation

Key Facts

• Operational since 2018

• Regional coverage

• Covers India + ~1500 km around it

• ~7–8 satellites

Special Feature

• Provides Standard Positioning Service (SPS) for civilians

• Restricted Service (RS) for military

UPSC Fact

• NavIC satellites carry atomic clocks for precise timing.

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Quick Comparison Table (UPSC Favourite)

System	Country	Coverage	Satellites
GPS	USA	Global	~30
GLONASS	Russia	Global	~24
Galileo	EU	Global	~30
BeiDou	China	Global	~35
NavIC	India	Regional (1500 km)	~7–8

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Important UPSC Concept

All these systems together are called:

GNSS (Global Navigation Satellite Systems)

These systems work using:

• Satellite constellation

• Atomic clocks

• Signal timing for position calculation

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✅ UPSC Prelims Trick

If a question asks “Which countries have independent global navigation systems?”

Answer will be:

• USA

• Russia

• China

• European Union

India has regional navigation (NavIC).