ISRO Satellites & Spacecrafts: Different Categories Which it Develops And Maintains
Indian Space Research Organisation has many categories of satellites and spacecrafts for it’s space missions and applications.
Let’s look at the key differences between GPS and NAVIC
1. Ownership
GPS (Global Positioning System) – United States government (Department of Defense)
NAVIC (Navigation with Indian Constellation) – Indian government (Indian Space Research Organisation – ISRO)
2. Development Motivation
GPS (Global Positioning System) – Developed during the Cold War for global military navigation
NAVIC (Navigation with Indian Constellation) – Developed after the Kargil War to ensure India’s self-reliance in satellite navigation
3. Launch Timeline
GPS (Global Positioning System) – Fully operational since 1995
NAVIC (Navigation with Indian Constellation) – Fully operational since 2016
4. Control Stations
GPS (Global Positioning System) – Global network of control stations
NAVIC (Navigation with Indian Constellation) – Ground stations located across India for monitoring and control
5. Independence
GPS (Global Positioning System) – Controlled by the U.S. government
NAVIC (Navigation with Indian Constellation) – Controlled by India, ensuring independence and security
6. Coverage
GPS (Global Positioning System) – Global coverage,
NAVIC (Navigation with Indian Constellation) – Regional coverage (India and up to 1,500 km beyond its borders)
7. Number of Satellites
GPS (Global Positioning System) – 31 active satellites in medium Earth orbit (MEO)
NAVIC (Navigation with Indian Constellation) – 7 satellites (3 in geostationary orbit, 4 in geosynchronous orbit)
8. Orbit Type
GPS (Global Positioning System) – Medium Earth orbit (~20,200 km altitude)
NAVIC (Navigation with Indian Constellation) – Geostationary and geosynchronous orbits (~36,000 km altitude)
9. Frequency Bands
GPS (Global Positioning System) – Single frequency (L1) for civilian use; dual for military (L1 and L5)
NAVIC (Navigation with Indian Constellation) – Dual frequency (L5 and S-band) for better accuracy and reliability
10. Atmospheric Error Mitigation
GPS (Global Positioning System) – Requires ground-based corrections for civilian accuracy
NAVIC (Navigation with Indian Constellation) – Dual-frequency mitigates atmospheric errors without external corrections
11. Encryption
GPS (Global Positioning System) – Encrypted service available for U.S. military and government
NAVIC (Navigation with Indian Constellation) – Encrypted service available for Indian military and government
12. Availability
GPS (Global Positioning System) – Available worldwide, 24/7
NAVIC (Navigation with Indian Constellation) – Available regionally, 24/7 within its coverage area
13. Target Audience
GPS (Global Positioning System) – Global civilian, military, and commercial use
NAVIC (Navigation with Indian Constellation) – Primarily Indian civilian, military, and commercial use
14. Service Types
GPS (Global Positioning System) – Standard Positioning Service (SPS) for civilians; Precise Positioning Service (PPS) for military
NAVIC (Navigation with Indian Constellation) – Standard Positioning Service (SPS) for civilians; Restricted Service (RS) for authorized users (military, government)
15. Accuracy
GPS (Global Positioning System) – Global accuracy of 10-20 meters for civilian use
NAVIC (Navigation with Indian Constellation) – Regional accuracy of 5-10 meters, optimized for the Indian region
16. Primary Applications
GPS (Global Positioning System) – Navigation, aviation, military, timing services globally
NAVIC (Navigation with Indian Constellation) – Navigation, defense, disaster management, agriculture, and maritime in India
17. Military Dependence
GPS (Global Positioning System) – Indian military relies on GPS for global navigation
NAVIC (Navigation with Indian Constellation) – Indian military uses NAVIC for secure, regional navigation
