Context:
Global Positioning System (GPS) is one of few everyday technologies that have had the kind of revolutionary impact on civilian, military, scientific, and urban realms, redefining our sense of location and impacting diverse sectors globally.
Relevance:
GS III: Security Challenges
Dimensions of the Article:
- Global Positioning System (GPS)
- Global Positioning System and International GNSS
Global Positioning System (GPS)
Developed by the U.S. Department of Defense in 1973, GPS consists of three primary components.
Space Segment
- 24 satellites across six orbits provide worldwide coverage for precise location tracking.
- Positioned 20,200 km above Earth, with four satellites per orbit completing two rotations daily.
Control Segment
- Ground stations globally ensure satellite functionality and precision, in line with 2020’s Standard Positioning Service (SPS) guidelines.
- The SPS outlines the expectations for GPS performance globally.
User Segment
- GPS services a variety of applications, from farming to defense, with over 6.5 billion GNSS (Global Navigation Satellite System) devices in 2021, projected to reach 10 billion by 2031, indicating its extensive reach.
Global Positioning System and International GNSS
GPS Operations
- Functions via radio signals from satellites at L1 and L2 frequencies for 3D and temporal positioning.
- Incorporates error adjustments like relativistic effects to enhance accuracy.
Timing and Precision
- Relies on atomic clocks in satellites for critical timing, essential for reducing location errors.
Global GNSS Landscape
- Various nations have their GNSS, including Australia, China, EU, India, Japan, South Korea, Russia, and the U.K.
- Russia’s GLONASS, the EU’s Galileo, and China’s BeiDou provide international coverage.
India’s Navigation Systems
- Initiated its Regional Navigation Satellite System, now known as NavIC, featuring seven satellites in mixed orbits.
- As of May 2023, a quartet of satellites supports terrestrial navigation, managed from Hassan, Karnataka, and Bhopal, Madhya Pradesh.
- NavIC’s satellites transmit on L5 and S bands, with newer additions utilizing the L1 band.
Enhancements to GPS in India
- The GAGAN system, a joint venture of ISRO and the Airports Authority of India, augments GPS for aviation safety within Indian airspace and delivers GPS corrections and integrity assurances.
-Source: The Hindu
