Fig. 1. Schematic diagram of tomographic PIV

Fig. 2. Principle of voxel intensity reconstruction

Fig. 3. Voxel projection and its intensity integration process

Fig. 4. The principle of the forward projected area method. (a) Front view direction; (b) top view direction

Fig. 5. Imaging process. (a) Actual imaging; (b) pinhole camera model imaging

Fig. 6. Schematic diagram of pinhole camera model

Fig. 7. Particle imaging intensity calculation methods. (a) PSF method; (b) line integral method

Fig. 8. Scattering intensity. (a) Schematic diagram of the scattering intensity of the meter received by the camera; (b) normalized scattering intensity of simulate particle

Fig. 9. Projection of particle fields of different p_ppp on camera 1. (a) p_ppp=0.0125; (b) p_ppp=0.025; (c) p_ppp=0.05; (d) p_ppp=0.1

Fig. 10. Memory occupied and time taken of different weight calculation methods under 100×100×40 voxels

Fig. 11. Reconstruction results. (a) Comparison of reconstruction accuracy with traditional backward methods; (b) comparison of reconstruction accuracy with TSM method

Fig. 11. Weight matrix section at the center of X direction. (a) Calculation results of traditional backward method; (b) calculation results of FPA

Fig. 12. The similarity of weight values corresponding to all pixel of CCD 1, 2, 3

Fig. 14. Layout of experimental equipment

Fig. 15. Experimental image noise extraction and fitting results. (a) Image noise distribution; (b) image noise frequency distribution and fitting results

Fig. 16. Noise intensity distribution at different σ and its influence on reconstruction accuracy.(a) Noise intensity distribution at different σ; (b) reconstruction accuracy at different σ

Fig. 17. Reconstruction results when the camera collects at different angles