Development and testing of GNSS-based landing system avionics

Test methods and criteria are needed to certify Global Navigation Satellite System (GNSS) Landing System (GLS) avionics. The government and industry committee developing GLS standards at RTCA Inc. is particularly concerned with the accuracy of the equipment when subjected to external radio frequency (RF) interference. The RTCA Special Committee 159 (SC-159) has allocated accuracy between ground and airborne system components in the range domain to facilitate system modularity and interoperability. This led to the development of range domain avionics test methods that previously were specified in the position domain. There are a number of considerations in balancing the need for adequate test coverage while maintaining reasonable test duration. The paper develops and validates the test statistics and criteria for the RTCA Minimum Operational Performance Standards (MOPS) GLS accuracy tests. The interference test suite contributes a critical piece to the LAAS interoperability puzzle by assuring the airborne integrity allocations are adequate.