scope:

This document provides the Minimum Operational Performance Standards (MOPS) for Airborne Navigation Equipment Using the Global Positioning System (GPS) Augmented by the Local Area Augmentation System (LAAS). The standards in the document define minimum performance requirements, functions, and features for LAAS airborne equipment to support CAT I, II and III precision approach operations. Compliance with these standards by manufacturers, installers, and users is recommended as a means of assuring that the equipment will satisfactorily perform its intended functions under conditions encountered in routine aeronautical operations. DO-253A superseded DO-253 and included: 1) Recommendations harmonized with the ICAO GNSS Panel Standards and Recommended Practices (SARPs), 2) The use of LAAS differential position to support area navigation, and 3) The easing of the LAAS Ground Subsystem Siting constraints (Ephemeris Error Protection). DO-253B harmonized the LAAS MOPS with the revised WAAS MOPS - DO-229D. DO-253C includes the earlier revisions and provides the requirements / standards for LAAS to support Cat. II and III precision approaches. In addition, the revision incorporates changes to existing Cat. I and positioning service standards, and includes velocity requirements to further support ADS-B.