Ambient gaseous leak detection using radial scanning computed tomography and optical remote sensing

摘要

We conducted a preliminary experiment in controlled ventilation chamber where a single source of Nitrous Oxide was released. A scanning Open Path Fourier Transform Infrared (OP-FTIR) system acquired Path Integrated Concentration (PIC) data of 19 beams scanned in a radial non-overlapping beam geometry. Prior to the experiment we conducted a calibration procedure by creating a homogeneous atmosphere inside the ventilation chamber. The Smooth Basis Function Minimization (SBFM) algorithm, which fits parametric distributions rather than fitting individual pixel concentrations, was used to reconstruct two-dimensional concentration maps from this beam geometry. The preliminary results show that good reconstructions are possible with this approach. Further, our calibration procedure could be suitable for any open path optical remote sensing instruments. In contrast to the complex beam geometries proposed in the past for CT, this radial scanning technique could be applied directly to air monitoring data from a variety of current optical sensing instruments. This development could vastly broaden the application of CT to obtain rapid reconstructions of ambient air pollution data.