GPS Accuracy

GPSGPSThe Global Positioning System (GPS) is a satellite-based navigation system operated by the U.S. Space Force that prov... accuracy describes how closely a GPS-derived position matches the true location on Earth's surface. Standard civilian GPS provides horizontal accuracy of approximately 3-5 meters under open-sky conditions, but actual performance varies depending on satellite geometry, atmospheric conditions, signal obstructions, and receiver quality. Understanding accuracy is critical for selecting appropriate equipment and methods for different applications. Factors affecting accuracySatellite geometry (quantified by Dilution of Precision, or DOP) has a major impact: more widely distributed visible satellites yield better accuracy. Atmospheric delays from the ionosphere and troposphere introduce ranging errors. Multipath reflections from nearby surfaces cause additional errors in urban and forested environments. Receiver quality, antenna design, and firmware algorithms also significantly influence results. Accuracy enhancement techniquesAugmentation methods dramatically improve GPS accuracy. Satellite-Based Augmentation Systems (SBAS) like WAAS provide 1-2 meter accuracy. Differential GPS (DGPS) using local reference stations achieves sub-meter results. Real-Time Kinematic (RTK) positioning delivers 1-2 centimeter accuracy, and Precise Point Positioning (PPP) achieves similar precision without a local base station. Understanding GPS accuracy is essential for matching positioning technology to application requirements. From smartphone navigation to precision surveying, selecting the appropriate accuracy level and augmentation method ensures reliable, fit-for-purpose geospatial dataGeospatial DataGeospatial data encompasses information about the location, shape, and relationships of physical features on Earth. I... collection.