RTCA DO-235C

The RTCA Task Force #1 Report on the Global Navigation Satellite System (GNSS) Transition and Implementation Strategy (September 1992) recommended that "the FAA should base GNSS initial operational implementation on the use of the U.S. GPS (Global Positioning System) national resource and appropriate augmentations". The Task Force also recommended that RTCA develop initial standards that will be used to certify GNSS equipment for operational use. The accuracy, integrity, availability and continuity of satellite-based navigation must be assured before it can be adopted into safety of life aviation use. Radio frequency interference (RFI) is a factor that potentially degrades system performance and one that must be examined with care.