Name the device that helps pilots determine aircraft position relative to runways and taxiways.

The device that helps pilots determine aircraft position relative to runways and taxiways is surface movement radar, also known as ground radar. This technology provides precise tracking of aircraft on the ground, allowing air traffic controllers and pilots to monitor movements in real-time. By utilizing radar, it enhances situational awareness and helps in preventing collisions on taxiways and runways, contributing to overall safety in airport operations.

While aircraft transponders do provide critical information about the aircraft's location, they are primarily used for tracking during flight and do not specifically aid in ground position determination relative to runways and taxiways. Visual references on charts are useful but may not offer the accuracy needed for real-time tracking on the ground. GPS systems, although beneficial for navigation, are not exclusively used for runway and taxiway positioning, and their accuracy can vary based on external conditions. Surface movement radar, however, is specifically designed for ground operations, making it the most relevant choice.