Abstract: The main purpose of this research is to manage simultaneous measurement of velocity and concentration in large cross sections by recording and processing images of cloud structures. Stack gas dispersion in an atmospheric boundary layer (ABL), was chosen as the test case and investigated both experimentally and numerically. Large scale particle image velocimetry (LS-PIV), which records cloud structures instead of individual particles, was used to obtain the velocity field. Light scattering technique (LST) was employed to determine the concentration of the pollutant from the same set of images. In addition, aspiration probe concentration measurements were performed. The test case was also simulated using the CFD solver FLUENT. Comparison revealed that there is a good agreement between the aspiration probe measurements and the CFD results. For the LST measurements, a non-linear relation between concentration and light intensity was observed.