Satellite-based navigation will be integrated into high-precision, high-integrity commercial airborne applications, including precision landing systems. One such system is the Global Positioning System (GPS) Landing System (GLS), which utilizes the GPS satellites for navigation. The most common precision landing system currently is the Instrument Landing System (ILS) which essentially uses the glideslope antenna as the Guidance Control Point (GCP). This portion of the ILS provides critical information, including vertical guidance and deviation from the prescribed glidepath, to the flight computer, pilot, and autopilot. The Navigation Reference Point (NRP) for the GLS, however, is the location of the GPS receiving antenna(s), where similar deviations are computed from a calculated glidepath. Since the GCP and the NRP are not co-located, it is necessary to translate the NRP to the GCP to resemble the ILS's direct connection to the other landing instruments. The effort the author will perform, with respect to the GLS, will be the error analysis of the location of the NRP and a limited number of methods to apply a lever-arm correction, the impact to system accuracy. This effort will take into account the errors generated by the attitude perturbations, as well as error inaccuracies of the current GPS system.