In this paper, PIV and DSPI as an alternative to stereo PIV on the measurements of 3-C velocity fields is analysed . DSPI as a velocimetry technique is described , including a discussion on the necessary requirements for going from a PIV setup into a DSPI setup and the different suitable geometries for combining PIV and DSPI. Some results from a turbulent boundary layer flow in a wind tunnel are presented including a quantitative comparison with the 3-C velocity data simultaneously measured with stereo PIV.