Noise in CAPPI scans can produce two error types. First, when dealing with poor signal-to-noise ratio CAPPI scans, random correlations may be as strong as the correlations between aerosol structures. Thus, the global maximum correlation region may not represent the mean movements of the aerosols, causing large errors in the wind results. Second, when noise causes random variations in the CCF maximum peak, the interpolation to gain sub-pixel resolution is subject to typically small error. A two-fold error analysis scheme is developed in this study. First, reliability of the CCF maximum region is determined (section 4.2.1). Then, the RMS-error of the wind estimate is determined (section 4.2.2).