A COMPARISON OF TWO INTEGRATED AIRBORNE POSITIONING AND ORIENTATION SYSTEMS

Abstract

Airborne remote sensing systems like Laser Scanners, Digital Line Cameras, Synthetic Aperture Radar (SAR) are systems of choice for fast acquisition of mass topographic data. For georeferencing purposes, these sensor systems rely on external positioning and orientation support of extremely demanding accuracy. Sensor position and orientation is typically provided by an integrated measurement and processing unit including a (differential) Global Positioning System (GPS) receiver and an Inertial Measurement Unit (IMU). Conventional analogue airborne photogrammetry and Digital Frame Cameras also benefit greatly from such external positioning/orientation provision. Two such integrated sensor positioning and orientation systems are commercially available: the CCNS AeroControl IIb of IGI of Kreuztal/Germany and the POS/AV510 of Applanix of Richmond/Canada. These two systems were flown side-by-side in the DLR (German Aerospace Centre) fixed-wing aircraft during a SAR data acquisition mission. Post mission data processing of the GPS and IMU data yielded separate sensor trajectories (position, velocity, orientation) for the two systems at a data rate of 200 Hz for the POS/AVTM510 and 50 Hz for the CCNS AeroControl IIb, for a total flight duration of about two hours and 40 min. The two trajectories are analysed and compared in order to identify any shortcomings in either system, and in order to cross-check if the two systems meet their advertised performance specifications.