Optoelectronics system for estimating measurement error of Image Pattern Correlation Technique

Abstract

Photogrammetric methods for in-flight deformation measurements have undeniable advantages: e.g. contactless measurements, measuring the entire surface and the relative simplicity of the setup. During the European research projects Advanced In-Flight Measurement Techniques (AIM and AIM2) an implementation of the photogrammetric method – Image Pattern Correlation Technique (IPCT) has been proposed. It had been successfully applied in several flight test campaigns. To evaluate the measurement error of photogrammetric methods either opto-geometric evaluations or digital modeling of synthetic images are commonly used. Some works indicate only error estimation, but without the explanation of its origin. The paper presents an approach for estimating the measurement error for the IPCT. An experimental system is developed including an imitator of the surface deformation and an additional optical sensor for measuring the present surface profile. The error is determined as a difference between the results of the optical sensor and the IPCT. The system allows to simulate a deformation with an amplitude of ±25 mm on a surface area of 380×380 mm2 in increments of 0.5 mm horizontally and 0.001 mm vertically, with a measurement accuracy of 0.075 mm. The system will be outlined in the paper and measurement results are presented.