Example of the sigma-clipping technique proposed in this work for six RRab stars, where the black line depicts the Fourier fit in the r band. The yellow dots represent the remaining data points, and the red dots represent the data points removed using the 3σ threshold with five iterations (left panel). The central and right panel shows the phase-binning method using bins of 0.05 width (in phase) and a 3σ and 2σ threshold with five iterations, respectively.