GPS III-Galileo/Altimeter Landing System for CAT IIIB: Concept and Analysis

Abstract

This paper contains a description and analysis of the performance of a future Global Navigation Satellite System (GNSS)/altimeter integration that is shown to have potential to provide the sensor accuracy and integrity needed for Category IIIB approaches. The concept takes advantage of independent position estimates to provide integrity and enhanced accuracy. The GNSS component is GPS III and Galileo, implying a circa 2020 time frame. The altimeter component is radar (or laser) with terrain elevation corrections. A feature of the concept is a method that adjusts sensor weights to achieve required integrity risk regardless of the magnitude of a fault error. The analysis focuses on sensor integrity and accuracy, and includes risk analysis, derivation of system parameters, and availability estimates with respect to CONUS.