Time resolved Tomo-PIV measurement is operated on flow past a hemisphere that is immersed in a laminar boundary layer. The sample frequency is 1000 Hz, with a reconstruction area of 110×46×21 mm^3. Reynolds number based on the height of the hemisphere is 1336. Low dimensional reconstruction of the flow velocity fields is calculated from the Proper Orthogonal Decomposition (POD) modes. The vortex in the animation is identified using the Lambda_ci criterion.