The ASM LINE OF SIGHT SKY ABSORPTION MONITOR
This is a prototype. The dashed line determines photometric conditions. A dot position on the time axis corresponds to the center of a 10mn wide gaussian averaging window. This prototype includes demodulation of images size (seeing) effects which amount to about 1% flux error per 0.1" seeing change. Also sporadic flux increases due to the bad image homogeneity of the DIMM telescope are removed.
Check earlier nights in the ESO
See also the data from LOSSAM at La Silla.