GPS/IMU Ultra-Tightly Coupled Integrity Monitoring

"Global Positioning System (GPS) applications which involve safety-of-flight operations (e.g. precision and non-precision approach) require integrity monitoring. Previous integrity monitoring techniques implemented took advantage of redundant observations(e.g. Receiver Autonomous Integrity Monitoring or RAIM) or off board resources such as wide area or local area augmentation. Recent advances have led to the development of ultra-tightly coupled (UTC) GPS/inertial solutions that provide significantlyimproved performance in the presence of signal interference. In this proposal, a UTC GPS/inertial receiver autonomous integrity monitoring (GI-RAIM) solution is proposed that enables robust detection, identification and rejection of faulty GPS satellites.Under the Phase II effort, it is proposed to build a GPS/inertial test-bed for evaluation and validation of the GI-RAIM algorithm. The performance will be demonstrated using data collected from the test-bed using a combination of analysis, simulation andlive satellite testing. To support GPS/inertial integrity testing at AFRL, an inertial simulator will also be delivered. The Phase II project will result in an UTC GPS/Inertial integrated system that can be demonstrated to meet the RTCA integrityrequirements for en-route, and non-precision approach with a goal of also enabling SCAT-1 precision approach and landing capability, all without reliance on the WAAS civil augmentation system."