Crab pulsar (PSR B0531+21) light curve obtained by folding the data with the period found using the maximum value of the first PC eigenvalue, P_PCA (as shown in Fig. 6), and compared to the period from the Jodrell Bank monthly ephemerides, P_JB. The Jodrell Bank period was computed using PINT at the observation time, and the period 〈P_JB〉_t was obtained by averaging over the whole transit (of duration t = 7200 s). The difference between the two methods is |p_pca−〈p_jb〉_t|= 0·1766rn.