Which of the following is NOT considered a 'Local' Position Reference System?

The selection of the answer highlights the understanding of different position reference systems and their classifications in relation to dynamic positioning (DP) operations. A 'Local' Position Reference System typically refers to systems that provide positioning information based on measurements taken in the immediate vicinity of the vessel, often using local references.

The DGNSS (Differential Global Navigation Satellite System) is not categorized as a local system because it relies on satellites and provides positioning data over a much broader scope, often used for global navigation rather than localized operations. In contrast, systems such as the laser ranging system, gyrocompass, and inertial navigation system provide localized, immediate positioning based on specific measurements relative to the vessel's environment or reference points.

Laser ranging systems utilize lasers to measure distances from the vessel to a target object, thus giving precise positional data locally. A gyrocompass provides heading information, which can aid in local navigation, while an inertial navigation system calculates a vessel's position based on motion sensors and can function well without external references when navigating locally.

Overall, distinguishing between local and broader navigation systems is crucial in understanding how different technologies contribute to dynamic positioning operations.