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Distance Check

GPS Driving Time Issues

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by

James Harrington
in

How GPS Calculates Driving Time

GPS devices calculate travel time using Global Navigation Satellite Systems (GNSS). Satellites send signals to Earth, allowing GNSS receivers to determine position. GPS incorporates pre-programmed maps with road details, speed limits, and sometimes traffic data for accuracy.

However, GPS can be inaccurate due to lagging behind real-world conditions or signal interference in urban areas. Dense buildings, tunnels, and underground structures can disrupt GPS effectiveness, creating challenges for signal integrity and data availability.

GPS satellites orbiting Earth, sending signals to a car with a visible navigation system

Factors Impacting GPS Accuracy

GPS inaccuracies stem from various factors:

  • Satellite clock errors
  • Ephemeris data imperfections
  • Atmospheric delays in the ionosphere and troposphere
  • Multipath problems in urban environments
  • Natural features like heavy foliage and winding roads

These issues can cause miscalculations and reduced precision in GPS positioning and navigation.

Mitigating GPS Inaccuracy

To address GPS inaccuracies, Real-Time Kinematic (RTK) and Inertial Navigation Systems (INS) are used:

  • RTK: Uses a base station to send corrections to GPS, reducing error margins to centimeters.
  • INS: Equipped with accelerometers and gyroscopes, tracks changes in velocity and orientation when GPS connectivity is interrupted.

These technologies enhance accuracy in autonomous vehicle (AV) systems, providing real-time navigation adjustments and creating a solid foundation for precise navigation in various scenarios.

Technology Enhancements for Better Estimates

Future GPS technology advancements aim to eliminate persistent inaccuracies:

  1. Improved GNSS: Enhanced satellite constellations for more detailed, real-time data transmission.
  2. Sensor fusion: Combines data from multiple sources (radar, LiDAR, cameras) for comprehensive environmental awareness.
  3. Deep learning: Identifies patterns and predicts variables to adapt to road conditions and unexpected events.

These technologies promise a more accurate and adaptive GPS experience, reducing navigation errors and improving estimated arrival times.

Futuristic visualization of enhanced GPS technologies including improved satellite constellations, sensor fusion, and deep learning integration

As GPS technology continues to evolve, we can expect more precise and reliable navigation experiences in the future. The integration of RTK-INS with advanced sensor fusion techniques paves the way for the next generation of autonomous vehicles, offering a level of accuracy that surpasses human capabilities.1

  1. Aboelmagd N, Noureldin A, El-Sheimy N. Fundamentals of Inertial Navigation, Satellite-based Positioning and their Integration. Springer; 2013.