Particle Reconstruction with Optical Transfer Functions Applied to Tomo-PIV-Experiments

Kurzfassung

A new approach to the weighting function, which describes particle imaging in the reconstruction process of tomographic PIV, is introduced. Instead of assuming a spatially homogeneous mapping function of a voxel to the images, a variable optical transfer function (OTF) is applied. By this method, the effects of optical distor-tions, introduced during the recording process, can be reduced considerably. The effect of blurred particle imaging and astigmatisms on reconstruction and correlation quality is investigated via simulated data. Reconstructions using a spa-tially varying OTF, calibrated to the imaging conditions, show a significant im-provement in reconstruction quality, correlation quality and accuracy of the particle peak position. First results on experimental data indicate a distinct reduc-tion in ghost particle intensity compared to other approaches.