Uncertainty of Spatial and Temporal velocity for High-speed PIV

High-speed PIV system can provide huge amount of images for PIV analysis. With frame straddling technique, the dynamic range of velocity could be improved with four image analysis technique. This technique sacrifices the temporal directional resolution to improve the dynamic ranges. Because total amount of the image information is constant, if we improve a spatial resolution, the temporal resolutions will decrease. There should be a sufficient conversion of spatial and temporal resolutions. The relation between sampling frequency and flow characteristic frequency in both spatial and temporal direction will be discussed.