Applications of Wavelet-Based Image Reconstruction to High- Speed Chemical Species Tomography with Severely Limited Data

Nataša Terzija1 and Hugh McCann1,

1School of Electrical Engineering, University of Manchester, Manchester M60 1QD, UK,

Natasa.Terzija@manchester.ac.uk

ABSTRACT

The use of wavelet-based image reconstruction methods is discussed for data inversion of limited path-integral data in hard-field tomography systems. As shown in our previous work, the Landweber iteration method allows stable solution of this tomography problem by incorporating suitable a priori information. We have previously presented a new method that uses a 2-D discrete wavelet transform as a smoothing function. In this paper, the new method is applied to different beam arrays that implement chemical species tomography system using near-IR spectroscopic absorption measurements, and which can be classified as producing severely limited data where both the number of viewing angles and the number of measurements are small. Results are presented for simulated phantoms and for experiments with propane plumes, showing excellent spatial localization and quantification. The improved convergence time of the new iterative algorithm is exploited in application to high-speed experimental data obtained from transient laboratory tests. The potential for the method to be applied to other hard-field tomographic modalities is considered.

Keywords Tomography, image reconstruction, wavelet transform, limited data