Showing papers on "Optical tomography published in 1984"
TL;DR: Experimental results quantitatively confirm a theoretical analysis of the noise in the reconstructed image, including the effects of correlated noise, position within the image, and spatial resolution.
Abstract: Optical tomography is used to map the iodine vapor density in a plane. Two-dimensional images are obtained with 1-cm spatial resolution using a fan beam geometry with a 28-cm radius fan source circle. The images are reconstructed using the convolution backprojection algorithm with data collected in 0.1 sec from 90 detectors on a full circle using 90–360 fan source positions. Experimental results quantitatively confirm a theoretical analysis of the noise in the reconstructed image, including the effects of correlated noise, position within the image, and spatial resolution. The noise amplitude–absorption length product for a 2-cm pixel size is 6 × 10−4 which is equivalent to an iodine concentration of 6 ppm.
63 citations
TL;DR: A tomographic procedure for reconstructing the density field around a helicopter rotor blade tip from remote optical line-of-sight measurements finds that very good reconstructions can be obtained using only a small number of views even when the width of view is smaller than the spatial extent of the object.
Abstract: In this paper, a tomographic procedure for reconstructing the density field around a helicopter rotor blade tip from remote optical line-of-sight measurements is discussed. Numerical model studies have been carried out to investigate the influence of the number of available views, limited width viewing, and ray bending on the reconstruction. Performance is measured in terms of the mean-square error. It is found that very good reconstructions can be obtained using only a small number of views even when the width of view is smaller than the spatial extent of the object. An iterative procedure is used to correct for ray bending due to refraction associated with the sharp density gradients (shocks).
52 citations
TL;DR: Experimental results confirm a theoretical analysis of noise in the reconstructed image, including the effects of correlated noise, position within the image, and spatial averaging.
Abstract: Optical absorption tomography is used to map the iodine-vapor density in a plane. Two-dimensional images are obtained with 1-cm spatial resolution by using a fan-beam geometry with a 56-cm-diameter source circle. Experimental results confirm a theoretical analysis of noise in the reconstructed image, including the effects of correlated noise, position within the image, and spatial averaging.
26 citations