Title :
Cascading filtered DTS data into a loosely-coupled GPS/INS system
Author :
Bell, W. Bryan ; Gore, Robert G. ; Cockrell, Larry D.
Author_Institution :
Lockheed Martin Tactical Aircraft Syst., Fort Worth, TX, USA
Abstract :
This paper addresses the integration of a subordinate Kalman filter processing terrain data into a Kalman filter integrating Global Positioning System (GPS) data and Inertial Navigation System (INS) data with limited computing resources. The study shows that modeling the difference between the horizontal position estimates supplied by the Digital Terrain System (DTS) and the integrating Kalman filter is sufficient for accurate solution integration. The two new error states required to model this difference are modeled as random walks driven by variable process noise. Augmenting the GPS/INS integrating Kalman Filter with the horizontal position offset states requires minute changes to the existing filter mechanization. Performance measurements of position, velocity and platform tilt error using Monte Carlo simulations show stable and acceptable navigation accuracy. An alternative integration of subordinate solutions scheme is also suggested and presented
Keywords :
Global Positioning System; Kalman filters; aircraft navigation; inertial navigation; military aircraft; Digital Terrain System; GPS; INS; filter mechanization; filtered DTS data; horizontal position estimates; loosely-coupled GPS/INS system; navigation accuracy; platform tilt error; random walks; subordinate Kalman filter; terrain data; variable process noise; Acceleration; Aircraft navigation; Fault tolerant systems; Global Positioning System; Inertial navigation; Kalman filters; Measurement; Military aircraft; Sensor systems; State estimation;
Conference_Titel :
Position Location and Navigation Symposium, IEEE 1998
Conference_Location :
Palm Springs, CA
Print_ISBN :
0-7803-4330-1
DOI :
10.1109/PLANS.1998.670217