Effect of light-collection geometry on reconstruction errors in Abel inversions.

The Abel inversion, used to reconstruct axisymmetric radial profiles from line-of-sight intensity measurements, is increasingly used to make spatially resolved combustion measurements. An Abel deconvolution is valid only when incoming rays are parallel, whereas most practical optical setups used for emission imaging consist of single-lens and multilens systems that collect light in a cone, over a nonzero solid angle. A ray-tracing simulation was performed to aid in understanding how optical collection geometry affects measured intensity signals and the resultant reconstructed emissivity profiles. Simulation results are compared with emission tomography measurements performed on an axisymmetric laminar diffusion flame.