Application of Airborne Scanner - Aerial Navigation

by Campbell, Jacob L

Abstract (Summary)
This dissertation explores the use of an Airborne Laser Scanner (ALS) for use in aircraft Terrain-Referenced Navigation (TRN). Position estimation techniques developed in this dissertation enable the use of large sets of high accuracy ALS measurements to solve for position in real-time. The explored techniques were then used to design, implement, and - for the first time ever - fly a real-time ALS-based TERRain Aided Inertial Navigator (TERRAIN) precision approach system. During the flight tests, the system provided meter-level horizontal and vertical positioning accuracies in real-time. The ALS-based TRN techniques discussed in the dissertation are constrained to the information found in the terrain shape domain. The data acquisition, pre-processing, and position estimation techniques of ALS TRN vary significantly from traditional radar altimeter-based TRN primarily due to differences in the measurement mechanism used in both TRN systems. First, traditional radar altimeter-based TRN senses the terrain contours traversed in the along-track direction, whereas ALS-based TRN makes measurements in the along-track and in the cross-track directions. The second difference is that the ALS laser’s milli-radian beamwidth has sufficient resolution to identify not only the ground, but also objects on the ground such as buildings. A radar altimeter with a beamwidth of several degrees can not observe the same level of detail. These differences increase the spectral content of the ground measurement data in the ALS-based system thus permitting high-accuracy position estimates. The described ALS TRN navigation techniques include methods to estimate the position based on the best match between ALS data and a high resolution/accuracy terrain database. Finally, the dissertation explores the certification path for an ALS-based landing system.
Bibliographical Information:


School:Ohio University

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:terrain referenced navigation lidar ladar airborne laser scanner landing approach system


Date of Publication:01/01/2006

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