A phantom station in a 2D RNAV system is defined as:

In the context of a 2D RNAV (Area Navigation) system, a phantom station is used to enhance navigation capabilities by allowing aircraft to determine their position using less conventional methods. The definition of a phantom station involves creating a waypoint based on specific navigation information.

When you define a phantom station as a waypoint derived from a radial and a DME (Distance Measuring Equipment) distance from a VOR/DME station, it implies that the station is not physically present but is virtually represented in the navigation system. The radial provides directional information from the VOR station, while the DME distance gives the precise distance to the aircraft from the VOR station. Together, these two pieces of information allow the RNAV system to calculate and display a position or a reference point that the aircraft can navigate towards.

This method is especially useful for enhancing situational awareness and can facilitate more direct routing in areas where traditional navigation aids may not exist or where optimal paths are desired. The creation of phantom stations effectively allows pilots and the aircraft's navigation systems to function in a more versatile manner, optimizing flight paths and improving overall navigation accuracy.