THE EXTERNAL SEEING AND THE WIND
J. Navarrete, ESO La Silla & Paranal Observatory
May 2005
DIMM Seeing statistics for 4 years of operation in Paranal (2001-2004), over 778127, samples.
CASE 1: For each wind direction, the frequency when a given direction was coincident with
DIMM seeing better or equal than 0.5 arcsec , the frequency of the wind speed in steps of 1 m/s. is shown too.
CASE 2: For each wind direction, the frequency when a given direction was coincident with 0.5”<DIMM seeing<=0.8” , the frequency of the wind speed in steps of 1 m/s. is shown too.
CASE 3: For each wind direction, the frequency when a given direction was coincident with 0.8”<seeing<=1.2”, and the frequency of the wind speed in steps of 1 m/s. is shown too.
CASE 4: For each wind direction, the frequency when a given direction was coincident with
seeing worse than 1.2 arcsec , the frequency of the wind speed in steps of 1 m/s is shown too..
The good
seeing (<=0.5”) as function of the wind The bad seeing (>1.2”) as
function of the wind.
|
FWHM<=0.5” |
0.5”<FWHM<=0.8” |
0.8”<FWHM<=1.2” |
FWHM>1.2” |
|
|
7% |
39% |
36% |
18% |
All data , 778127 samples |
The DIMM seeing by
years:
|
FWHM<=0.5” |
0.5”<FWHM<=0.8” |
0.8”<FWHM<=1.2” |
FWHM>1.2” |
|
|
9% |
40% |
35% |
16% |
2001 |
|
2% |
33% |
42% |
23% |
2002 |
|
9% |
43% |
32% |
16% |
2003 |
|
7% |
39% |
36% |
18% |
2004 |