Interested to see your results. I attach my own (using 3-el Yagi, FCDP+, Spectrum Lab) covering the same period in 30m intervals. You will see that all three of us saw the same small uplift at around 2am.
Of course there are at least three other factors to take into account: the diurnal variation due to the rotation of the earth, the changing altitude of the radiant, and above all the changing geometry of the radiant-radar-our receivers that William mentioned. Nevertheless that 2am rise gives pause for thought. I have a lot more work to do on my data yet but will post more when I have it.