GPS / Atomic Disciplining
Whether the oscillator is actively steered by a satellite timing signal or a built-in atomic reference.
Disciplining compares an oscillator with a reference and adjusts it toward that reference. It differs from simply using a particular oscillator technology.
GPS / Atomic Disciplining — External Clock
For an External Clock, disciplining can maintain agreement with a reference over time. A GPS-disciplined clock uses received satellite timing; another design may steer a crystal oscillator from an internal atomic reference. The implementation determines its actual behaviour.
“Yes” requires an explicit disciplining or locking arrangement. A free-running oven-controlled crystal oscillator is not disciplined merely because its temperature is controlled. Likewise, the word “rubidium” identifies a technology without necessarily describing how another oscillator is steered.
Compare the reference requirements and stated locked performance. A plain external-reference input does not establish built-in GPS or atomic disciplining. Satellite-based operation also requires suitable reception. This feature alone does not rank short-term stability, phase noise or sound quality in an audio system.