Performance of GPS-Aided INS during High-Dynamic Maneuvers
Abstract
This these explores the unstable characteristic of an integrated inertial navigation system (INS) and Global Positioning System (GPS) receiver. During high-dynamic maneuvers, the INS Kalman filter provides velocity estimates to the GPS receiver code loop in an attempt to remove doppler-induced tracking errors. The GPS receiver Kalman filter, in turn, provides position and velocity estimates to correct INS errors. Due to the suboptimal nature of the two individual filters, this closed-loop process neglects key elements of information: time and spatial correlation. Therefore, this closed-loop system quickly becomes unstable during high-dynamic maneuvers, resulting in degraded navigational performance. Truth models of the INS and GPS receiver are developed. Kalman filters based on these two models are combined to yield a joint-solution model Kalman filter which serves as an indication of the best structure of integration possible. The eigenvalues of the basic INS error dynamics model, when subjected to various dynamic scenarios, are examined. A candidate maneuver is selected to compare the performance of five systems: the INS truth model, the GPS receiver truth model, the joint solution model, a two- filter system containing the INS and GPS receiver truth models, and a two-filter system containing reduced-order models of the INS and GPS receiver indicative of current system configuration.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA194624
Entities
People
- Joseph R. Cunningham
Organizations
- Air Force Institute of Technology