Tomographic particle image velocimetry (TPIV) data were acquired in the logarithmic region of a zero pres- sure gradient turbulent boundary layer °ow at friction Reynolds number Re¿ = 1160. Experiments were conducted in a suction type wind tunnel seeded with olive oil particles of diameter » 1¹m. The volume of interest was illuminated by two Nd:YAG laser beams expanded with appropri- ate optics into sheets of 8mm thickness in the wall-normal direction (z). Images were acquired by four 2k x 2k pixel cameras, and correlation of reconstructed ¯elds provided the full velocity gradient tensor in a vol- ume of 0.7± x 0.7± x 0.07±, which resolved the region z+ = 70-150 in the log layer. Various vortex identi¯cation techniques, such as Galilean decomposition and iso-surfaces of two- and three-dimensional swirl, were utilized to visualize and analyze the eddy structures present in instanta- neous ¯elds. The results of the present study will be compared to results from earlier experimental studies that relied on planar PIV data only to identify vortices and vortex packets as well as from a direct numerical simulation of fully developed channel °ow at comparable Re¿ . 體視層析粒子成像測速系統(tǒng)(Tomo-PIV) Imager sCMOS PIV相機 用于粒子成像測速(PIV)的熒光示蹤粒子