2026 Pilot Café IFR Practice Test – Complete Exam Preparation

Differential GPS (DGPS) improves accuracy by correcting errors from known ground locations. This system uses a network of fixed ground-based reference stations that continuously monitor the GPS satellite signals. Each station calculates its position based on the satellites and compares it to its known location. The difference between the calculated position and the actual position of these reference stations allows DGPS to generate correction signals that account for errors caused by atmospheric disturbances, satellite clock errors, and signal multipath.

When a DGPS-equipped receiver in an aircraft receives these correction signals, it can adjust its position calculations, significantly enhancing overall accuracy compared to standard GPS. This capability is especially critical in aviation and maritime navigation, where precision is paramount for safety and operational effectiveness.