Optical tomography system using charge-coupled device

Abstract

This research presents an application of Charge-Coupled Device (CCD) linear sensor and laser diode in an optical tomography system. Optical tomography is a non-invasive and non-intrusive method of capturing a cross-sectional image of multiphase flow. The measurements are based on the final light intensity received by the sensor and this approach is limited to detecting solid objects only. The aim of this research was to analyse and demonstrate the capability of laser with a CCD in an optical tomography system for detecting different types of opaque objects in crystal clear water. The image reconstruction algorithms used in this research were filtered images of Linear Back Projection algorithms. These algorithms were programmed using LabVIEW programming software. Experiments in detecting solid and transparent objects were conducted, including experiments of rising air bubbles analysis. Based on the results, statistical analysis was performed to verify that the captured data were valid compared to the actual object data. The diameter and image of static solid and transparent objects were captured by this system, with 320 image views giving less area error than 160-views. This suggests that high image view resulted in high resolution image reconstruction. A moving object’s characteristics such as diameter, path and velocity can also be observed. The accuracy of this system in detecting object acceleration was 82%, while the average velocity of rising air bubbles captured was 0.2328 m/s. In conclusion, this research has successfully developed a non-intrusive and non-invasive optical tomography system that can detect static and moving objects in crystal clear water.