1A Performance Analysis of a Tightly Coupled GPS/Inertial System for Two Integrity Monitoring Methods

Use of an integrated GPS/inertial system can be effective in mitigating the effects of GPS signal interference such as intentional jamming. Currently the GPS/Inertial Working Group of RTCA SC-159 is developing requirements and test procedures for a tightly coupled GPS/inertial system. To support this Working Group, this paper investigates two of the key issues being addressed by the Working Group. The first issue is how well a tightly coupled GPS/inertial system can detect slowly growing errors. This paper investigates this issue for two integrity monitoring methods. The other issue relates to how long the system can coast upon complete loss of GPS signals caused by interference. Using analytic formulas, this paper determines maximum coasting times possible under various scenarios