Application of stereo laser tracking methods for quantifying flight dynamics - Ⅱ

摘要

Conventional tracking systems measure time-space-position data and collect imagery to quantify the flight dynamics of tracked targets. A major obstacle that severely impacts the accuracy of the target characterization is atmospheric turbulence induced distortion of the tracking laser beam and imagery degradations. Tracking occurs in a continuously changing atmosphere resulting in rapid variations in the tracking laser beam and distorted imagery. These atmospheric effects, combined with other degradation effects such as measurement system motion, defocus blur, and spatially varying noise, severely limit the viability and accuracy of many tracking and imagery-based analysis methods. In 2007, using a high speed sled test, the feasibility of quantifying flight dynamics with stereo laser tracking and multi-video imagery was demonstrated. The technique acquires stereo views (two or more) of a moving test article that has an applied random speckle (dot) pattern painted on the surface to provide unique tracking points. The stereo views are reconciled via coordinate transformations and correlation of the transformed images. The 2007 results demonstrated that dual laser tracker data can be used to update camera calibration data for stereo imaging to extend the image correlation approach to moving field of view applications such as missile tracking and missile performance characterization, e.g., attitude measurements. However, these results were predominantly qualitative in nature, focusing on the degree of correlation. This paper will present quantitative results from 2008 outdoor centrifuge tests and assess the digital image correlation accuracy for time varying attitude and position measurements.