UPSC Prelims 2023 Q57: Science & Technology – Space Technology & Astronomy
- (a) Australia
- (b) Canada
- (c) Israel
- (d) Japan
Answer: (d) Japan
Explanation
Countries with Own Satellite Navigation Systems
| Country | Satellite Navigation System | Status |
|---|---|---|
| USA | GPS (Global Positioning System) | Operational since 1995 |
| Russia | GLONASS | Operational |
| European Union | Galileo | Operational |
| China | BeiDou (BDS) | Operational (global coverage 2020) |
| India | NavIC (Navigation with Indian Constellation) / IRNSS | Operational |
| Japan | QZSS (Quasi-Zenith Satellite System) | Operational |
From the options:
- Australia: No independent satellite navigation system
- Canada: No independent system (uses GPS)
- Israel: No independent system
- Japan: QZSS — a regional augmentation system for Asia-Pacific, developed domestically
Answer: (d) Japan.
Why each option is right or wrong
- (a) Incorrect. Australia does not have its own satellite navigation system — it relies on GPS and has ground-based augmentation but no independent constellation.
- (b) Incorrect. Canada relies on the US GPS system — it has no independent satellite navigation constellation.
- (c) Incorrect. Israel does not have its own satellite navigation system — it uses GPS for civilian and military purposes.
- (d) CORRECT. Japan has its own satellite navigation system — the Quasi-Zenith Satellite System (QZSS), which provides high-precision positioning over Japan and the Asia-Pacific region.
Key point
Japan's QZSS (Quasi-Zenith Satellite System) = Japan's own satellite navigation system. The six major global/regional systems: GPS (US), GLONASS (Russia), Galileo (EU), BeiDou (China), NavIC (India), QZSS (Japan).
Remember
Japan has its own satellite navigation system — the Quasi-Zenith Satellite System (QZSS) — providing high-precision positioning for Japan and the Asia-Pacific region. Australia, Canada, and Israel do not have independent satellite navigation systems.
Common mistakes
- Thinking Australia or Canada have their own systems — they are advanced countries but rely on GPS for navigation.
- Not knowing QZSS — Japan's system operates in a quasi-zenith orbit to provide near-constant satellite availability over Japan's mountainous terrain.
- Confusing regional augmentation (like SBAS) with independent navigation systems — QZSS is an independent Japanese constellation.
Exam tip
Six independent satellite navigation systems: GPS, GLONASS, Galileo, BeiDou, NavIC, QZSS. Remember: GGGBNQ or use the country names USA, Russia, EU, China, India, Japan. Of the options given, only Japan has its own system.
Sources
- Cabinet Office, Government of Japan — Quasi-Zenith Satellite System (QZSS)
- ISRO — NavIC and Global Navigation Satellite Systems