Padova and Asiago Observatories

Transcription

1 Padova and Asiago Observatories First results of the Ekar Observatory Meteorological Station Claudi R.U., Fantinel D., Bozzato E., Contri L., Martorana G. Technical Report N. 13 February 1997 Vicolo dell Osservatorio,5 - I PADOVA - Tel. +39/49/ Fax +39/49/ C.P.128,I Asiago (VI) - Tel. 0424/ (Pennar) - FAX

2 If you wish to receive this issue, please contact the Editor: R.U. Claudi Osservatorio Astronomico di Padova Padova - Italy Tel.: FAX: CLAUDI@ASTRPD.PD.ASTRO.IT

3 Abstract In this report the results obtained with the Ekar meteorological station in its first two years of duty ( ) are shown. Only the temperature and relative humidity data for the external and for the dome conditions are illustrated. Data concerning the telescope structure, mirrors and other temperature values, are available in the meteorological data archive.

4 4 1 Meteo Ekar Observatory The metereological station at the Cima Ekar Observatory was installed in the 182 cm Telescope dome with its set of sensors at the beginning of the Up to day a set of 12 sensors is on duty in order to register the variations of external and dome temperature and relative humidity together with Telescope structure and mirror temperatures. A complete description of the meteorological data acquisition and the archiving systems is given in Claudi et al while a description of the 182 telescope is given in Gratton et al and Claudi and Cremonese The position and the elevation of the dome center are given in Table 1; metereological sensors are positioned 15 m above the level of ground indicated in Table 1. East Longitude Latitude Elevation +00 h E +45 D N 1350 m Table 1: Geographical coordinates of the 182 telescope dome For each meteorological data istantaneous value, maximum and minimum values, average on short and long time bases are stored. The short time base is one hour interval while the long time base is one day. All parameters result from analog levels sampled every minute, digitally converted; the resolution of the exploited sensors is the following: 1. Temperature sensor, type TP01, Ekar number 1 and 3, resolution 0.1 C; 2. Rel. Humidity Sensor, type UM01, Ekar number 2 and 4, resolution 1%. Statistical values and differences between some parameters are evaluated off line by means of dedicated IDL procedures. 2 Environmental data for year 1995 In this paragraph all the evironmental data collected by the meteorological station at Ekar in the 1995 are presented. During the period between the 10 th of February and the 30 th of March the station was not operative because of maintenance works at the telescope, the period of missing data corresponds to the straight line on all diagrams.

5 5 Figure 1: External averaged Temperature registered in 1995 Figure 2: External maximum Temperature registered in 1995

6 6 Figure 3: External minimum Temperature registered in 1995 Figure 4: External Temperature excursion as evaluated from the maximum and minimum values of the external Temperature in 1995

7 7 Figure 5:Average dome Temperature registered in 1995 Figure 6: Dome maximum Temperature values registered in 1995

8 8 Figure 7: Dome minimum Temperature registered in 1995 Figure 8: Dome Temperature excursion as evaluated from the dome temperature max and minima values registered in 1995

9 9 Figure 9: Difference between external values as obtained in 1995 and dome averaged Temperature Figure 10: Averaged values of the external Relative Humidity registered in the 1995

10 10 Figure 11: Maximum values of the external Relative Humidity registered in 1995 Figure 12: Minimum values of the external Relative Humidity registered in 1995

11 11 Figure 13: Annual excursion of the external Relative Humidity for the 1995 Figure 14: Averaged values of the dome Relative Humidity as registered in 1995

12 12 Figure 15: Maximum values of the dome Relative Humidity as registered in 1995 Figure 16: Minimum values of the dome Relative Humidity as registered in 1995

13 13 Figure 17: Annual excursion of the dome Relative Humidity for 1995 Figure 18: Difference between external Humidity values as obtained in 1995 and dome averaged Relative

14 14 Figure 19: Diurnal variation of the external Temperature during 1995 Figure 20: Diurnal variation of the dome Temperature during 1995

15 15 Figure 21: Diurnal variation of the external Relative Humidity during 1995 Figure 22: Diurnal variation of the dome Relative Humidity during 1995

16 16 3 Environmental data for year 1996 In this paragraph one presents all the evironmental data collected by the meteorological station at Ekar in the Figure 23: External averaged Temperature registered in 1996 Figure 24: External maximum Temperature registered in 1996

17 17 Figure 25: External minimum Temperature registered in 1996 Figure 26: External Temperature excursion as evaluated from the external Temperature max and minimum values registered in 1996

18 18 Figure 27: Average dome Temperature registered in 1996 Figure 28: Maximum dome Temperature registered in 1996

19 19 Figure 29: Minimum dome Temperature registered in 1996 Figure 30: Dome Temperature excursion as evaluated from the dome max and minimum values registered in 1996

20 20 Figure 31: Difference between the averaged values of the external and dome Temperature as obtained in 1996 Figure 32: Averaged values of the external Relative Humidity registered in 1996

21 21 Figure 33: Maximum values of the external Relative Humidity registered in 1996 Figure 34: Minimum values of the external Relative Humidity registered in 1996

22 22 Figure 35: Annual excursion of the external Relative Humidity for the 1996 Figure 36: Averaged values of the dome Relative Humidity as registered in 1996

23 23 Figure 37: Maximum values of the dome Relative Humidity as registered in 1996 Figure 38: Minimum values of the dome Relative Humidity as registered in 1996

24 24 Figure 39: Annual excursion of the dome Relative Humidity for the 1996 Figure 40: Difference between external and dome averaged Relative Humidity as obtained in 1996

25 25 Figure 41: Diurnal variation of the external Temperature during 1996 Figure 42: Diurnal variation of the dome Temperature during 1996

26 26 Figure 43: Diurnal variation of the external Relative Humidity during 1996 Figure 44: Diurnal variation of the dome Relative Humidity during 1996

27 27 4 Statistical data for environmental variables In this paragraph a very simple statistical evaluation on the large ammount of collected data by the metereological station is illustrated. In the Table 2 the minimum, maximum, average and median values of the external and dome temperature for 1995 and 1996 are listed. T Min Date T Max Date <T> T Median ±0.1 o C ±0.1 o C o C o C T ext /12/ /7/22 8±7 8.8 T dome /11/ /6/7 12± T ext /12/ /6/13 6±7 6.4 T dome /12/ /8/23 11± Table 2: Statistical data evaluated over one year for the Temperature. In Table 3 the same values are listed for the Relative Humidity. The last column of the table shows the number of nights for which the relative humidity rate was greater than the 95%, corresponding to threshold value for the operativity of the telescope. The night was defined as a mean interval of 10 hours centered on midnight. (RH) Min Date (RH) Max Date ±0.1% ±0.1% (RH) ext /1/26 (RH) dome /2/ /8/9 (RH) ext /10/ /1/1 (RH) dome /5/ /8/29 <(RH)> (RH) Median # Nigths % % (RH)>95% (RH) ext ± (RH) dome ± (RH) ext ± (RH) dome ± Table 3: Statistical data evaluated over one year for the Relative Humidity

28 28 5 Conclusions In this report the capacity of the meteorological station at cima Ekar to monitor and register the environmental parameters was depicted and some examples of utilizations of collected data were also provided. Data relative to the telescope structure and mirror parameters variations are not explicity shown; however they are available in the meteorological archive of cima Ekar. When this station will be coupled with a seeing monitor system it will be possible to verify and evaluate the bad seeing sources inside and outside the dome. References 1. Claudi R.U., Fantinel D., Bozzato E., Contri L., Martorana G., 1996, Technical Report N Claudi R.U., Cremonese G., 1993, Asiago and Padova Observatories 3. Gratton R., Bonoli C., Bortoletto F., Claudi R.U., Falomo R., Ortolani S., 1992, Il telescopio Copernico (In Italian)