1. Master’s Thesis Defense
Electro-Optics and Photonics
Wednesday, November 15, 2017
10:00 AM FH 580
All are welcome to attend.
Quantitative Analysis of 3D Images formed using Range Compressed Holography
Thomas Welsh University of Dayton
Abstract
Range compressed holography is a technique that uses multiple 2D, single wavelength holograms in order to create a range compressed 3D image of a scene. Typically, these range compressed 3D images are described in terms of system parameters such as SNR and resolution in each of the dimensions. While these quantify some aspects of the resulting 3D data product, the overall performance may only be qualitatively analyzed. What is needed is a holistic metric that encompasses these system parameters as well as the nonlinear method of reconstruction of surfaces within volume noise. Representing the images as point clouds allows conventional point cloud metrics to be applied. The metric used here is the Point Cloud Library’s fitness score, which calculates the mean squared Euclidean distance between the reconstructed point cloud and the reference point cloud. Two scenes were created, one a flat plate to test range precision only and the other a more complex scene including a vehicle on a flat surface to account for cross-range resolution impacts on the mean squared Euclidean distance. The range variances for surface reconstructions of the flat plate were measured for simulations and experiments and are equivalent to the mean squared Euclidean distance due to the target’s range being independent of the cross-range. The mean squared Euclidean distance was also found for the complex scene through simulations. The simulations and experiment varied signal photons, bandwidth, and speckle realizations to observe the impacts on image quality using a quantitative measurement. The purpose of this thesis is to use the metric to understand how each of the variables impacts image quality, and determine the most signal photon efficient way to collect data for range-compressed holography.