The main goal of the RISE-PSPT project consisted in planning and realizing a network of coordinated telescopes, placed at different longitudes, in order to make accurate and continued photometric observations of the Sun’s full disk on different wavelengths in the continuous and in the CaII K line.
As we said in the previous section, three PSPT telescopes were realised and two of their are operating at present in Rome and Mauna Loa.
At the start of our study upon the quality of the data acquired in Rome, we thought it was important to record the number di days of observation since the telescope started its activity. In Figures 7.1 and 7.2 we show histograms of the days of observations calculated each month and each year. It can be noticed that the total number of the days of observation has increased as time goes on.
In Figure 7.1, the months without observations, recorded in the summer of 1997, are due to the first upgrade of the system, described in the preceding chapter, whereas, for the days of observation recorded in the month of September 2001, we must take into account the fact that a few days have been lost because of the transfer of the telescope from Rome to Monte Porzio Catone.
Of course, among the two sites hosting the PSPT telescopes currently in operation, Rome is the least advantaged from an observational point of view, since unfavourable atmospheric conditions are more likely. However, the number of days of observation recorded so far has allowed us to create a significant data archive, considering that the Rome PSPT is the only telescope within the network which has made daily observations from the start of the ascending phase of the solar cycle number 23.
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FIGURE 7.1: Days of observations of the Rome PSPT by month and by year. (in September-October-November 2004 the camera CCD was repaired).
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FIGURE 7.2: Total observation days by year since July 1996.
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FIGURE 7.3: Total observation days by month since July 1996.