Which technology complements GPS to enhance its accuracy through ground-based corrections?

The correct answer, which refers to Satellite-Based Augmentation Systems (SBAS), highlights a technology designed to improve the accuracy and reliability of GPS signals. SBAS provides corrections to the GPS signals by utilizing ground stations that monitor the satellite signals and satellite relays to broadcast these corrections back to users.

This system addresses the inherent limitations of GPS, such as signal reflection, atmospheric interference, and satellite geometry, thereby enhancing positional accuracy. One notable implementation of SBAS is the Wide Area Augmentation System (WAAS), which operates in the United States, providing additional corrections to users, especially in aviation.

RAIM (Receiver Autonomous Integrity Monitoring) also plays a role in ensuring the integrity of GPS signals by allowing the receiver to determine the reliability of the satellite signals it is receiving. However, it does not provide ground-based corrections like SBAS does. Distance Measuring Equipment (DME) pertains to a different technology that measures distance from a station using radar, and while it is useful in navigation, it does not complement GPS accuracy in the manner that SBAS does.

Therefore, SBAS stands out as the technology that enhances GPS accuracy through its specific method of ground-based corrections, making it the correct choice in this context.