Question

What are the limitations of Global Positioning System (GPS)? Explain.

Hint:

If your GPS device cannot clearly "see" the open sky, the satellites cannot pinpoint your location!

Answer 1

Step 1: Concept
While highly accurate, the GPS relies on relatively weak radio signals transmitted from space, which are vulnerable to environmental and technological interference.

Step 2: Meaning
Certain physical conditions prevent the receiver from accurately calculating the distance to the satellites, causing errors or total loss of positioning.

Step 3: Analysis

• Line of Sight Requirement: GPS signals cannot penetrate solid objects. They fail indoors, underground, underwater, and are severely degraded by dense forest canopies.
• Multipath Error: In urban areas, signals bounce off tall buildings or large water bodies before reaching the receiver, increasing the travel time and causing positional inaccuracies.
• Atmospheric Delays: The signal speed fluctuates as it passes through charged particles in the ionosphere and water vapor in the troposphere.
• Hardware Constraints: Mobile GPS receivers consume significant battery power, limiting their use in remote field operations without backup power.

Step 4: Conclusion
The system is fundamentally limited by obstructed skies, signal reflection, and atmospheric interference. Final Answer: The main limitations of GPS include the strict need for an unobstructed line of sight to the sky (failing indoors or under dense canopies), susceptibility to multipath errors (signals bouncing off tall buildings), signal degradation from atmospheric interference, and high battery drain in mobile receivers.