National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Impact of the troposphere on the inosphere
Koucká Knížová, Petra ; Mošna, Zbyšek ; Potužníková, Kateřina ; Boška, Josef ; Kouba, Daniel
Ionosphere represents weakly ionized plasma that reflects solar and geomagnetic activity and processes\nin the neutral atmosphere. Correlation of long time series of the ionospheric plasma critical frequencies,\nobtained by mean of vertical sounding from European stations, is analysed with respect to latitudinal and\nlongitudinal difference and surface distance of stations. Time series of critical frequencies are highly correlated\nreflecting the dominant solar influence. Correlation coefficients are high not only for raw data and subtracted\nmean courses but for fluctuations around mean as well. At the surface distance exceeding 1000 km and/ or about\n10 degrees of latitudinal difference between stations, the correlation coefficients of fluctuations decrease\nrapidly. Such effect is less visible on the latitudinal dependence, where the correlation coefficients decrease with\nincreasing distance with less pronounced threshold. We explain the existence of the ‘break point’ at 10 degrees\nin longitude and/or 1000 km by the ‘local’ influence of the neutral atmosphere and the wave activity. As a\npossible source of the common influence on scale 1000 km/10 degree we propose tropospheric systems that are\nknown to be an important source of atmospheric waves in a broad period range. Large tropospheric mesoscale\nsystems have typically up to 2000 km in size.
Physical and astronomical discussions
Oupický, Pavel
Paper is oriented on the problem parts of physic and astronomy .\nLast year I tried a few considerations about the physical astronomical problems (the FAU I.) in which I did not have a clear or vice versa, I think that they clearly have .. in anything but I'm not too sure, especially with some of the problems was clear to me that some of my comments may be next as they say .. and it was one of the motivations that led me to this sequel .. something i will continue here, something correct and perhaps in between appear as something new and interesting. This time I am going to deal with the following areas of concern of physics and astronomy.
The Virtual Imaging of the Distant Objects by Longfocal Positive Lenses and Concave Mirrors
Rail, Zdeněk ; Vápenka, David
The longfocal positive lenses and concave mirrors can serve as optical elements increasing the angular dimensions of the distant objects similarly to telescope.\nThese properties could be probably used by ancient observers before the discovery of telescope.\nOur paper brings optical analysis and results of visual astronomical observations with the longfocal positive lens.
The Catadioptric System of G.M. Popov of the Observatory of Úpice
Rail, Zdeněk ; Melich, Zbyněk
During the Sixties of the Twentieth Century series of two-mirror catadioptric telescopes were designed with a correcting lens in front of their secondary mirror. One of the first designers of these devices was P.P. Argunov. His optical designs were further developed by G.M. Popov, J. Klevcov and other opticians. In 2005 one telescope of a Popov system of diameter 305 mm was manufactured in the Development Optical Workshop of Academy of Sciences of Czech Republic /now Institute of Plasma Physics of AS CR,v.v.i.-Toptec/ in Turnov. The telescope was intended to substitute an older Maksutov-Cassegrain telescope of diameter of 260 mm of the Observatory in Úpice which required the reconstruction. In this paper we present an optical design of the Popov´s system of the Observatory in Úpice and compare it with an equal commercial Schmidt-Cassegrain telescope and further devices.\n
The Spherochromatic Aberration of the Clark‘s Objective Lens of the Ondřejov Observatory
Rail, Zdeněk ; Šrajer, Bohdan ; Jareš, Daniel ; Vápenka, David ; Pintr, Pavel
In our paper the results of mathematical simulations of the residual aberrations of Clark‘s 8 inch (diameter 203.2 mm) objective lens are presented. This achromatic dublet has been used at the Ondřejov Observatory for more than 100 years mostly for solar observation.

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