[show abstract][hide abstract] ABSTRACT: Results of 2005-2007 campaign of measurement of the optical turbulence vertical distribution above Mt. Maidanak are presented. Measurements are performed with the MASS (Multi-Aperture Scintillation Sensor) device which is widely used in similar studies during last years at several observatories across the world. The data analysis shows that median seeing in free atmosphere (at altitudes above 0.5km) is 0.46 arcsec and median isoplanatic angle is 2.47 arcsec. Given a rather long atmospheric coherence time (about 7 ms when the seeing is good) such conditions are favorable for adaptive optics and interferometry in the visible and near-IR. Comment: Accepted for publication in Astronomy Letters, V.35 (2009); 14 pages, 8 figures
[show abstract][hide abstract] ABSTRACT: The night-time seeing measurements obtained with the ESO Differential
Image Motion Monitor at Mt. Maidanak from August 1996, up to June 1999
are presented. This instrument was also used for seeing estimation at La
Silla and Paranal Observatories in Chile in 1988 - 1996. The median
value of seeing--(beta) FWHM (the full width at half maximum
of a long-exposure stellar image at zenith at (lambda) equals 500 nm)
for the entire period of observations is 0.69 arcsec. For the La Silla
and Paranal Observatories, this parameter is 0.87 and 0.66 arcsec,
[show abstract][hide abstract] ABSTRACT: Various parameters of the atmospheric turbulence above the Maidanak observatory located in Uzbekistan Republik were measured on 9 nights in July 1998 with three complementary instruments: Differential Image Motion Monitor (DIMM), Generalized Seeing Monitor (GSM) and two Scintillation Photometers (SP). Median FWHM seeing was equal to 0:64 00 , the median wavefront outer scale L 0 = 25:9 m, median isoplanatic angle ` 0 = 2:48 00 . Temporal evolution of the wavefront can be described by several layers moving at slow velocities (mostly less than 2 m=s and never exceeding 10 m=s) with predominant direction from the West. There was no correlation between wavefront velocity and the wind velocity at ground level. Turbulence in the 3 Gamma 30 m surface layer was not important, contributing on the average 10% to the total C 2 n integral (except on one occasion when it was very strong and dominant). Independent measurements of the free-atmosphere seeing (excluding the first kilometer above...
[show abstract][hide abstract] ABSTRACT: The second of the IRIS network instruments was commissioned in August 1988 at Kumbel mountain, located 75 km from Tashkent (U.S.S.R.). Atmospheric and operating conditions on Kumbel are discussed, as well as preliminary results derived from this station's global solar oscillation measurements.
Solar Physics 01/1991; 133(1):51-56. · 3.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: We present the results of our 2005–2007 campaign to measure the vertical distribution of optical turbulence above Mount Maidanak.
The measurements were performed with the MASS instrument, a multi-aperture scintillation sensor that has been widely used
for such studies in recent years at many observatories worldwide. Analysis of the data shows that the median seeing in the
free atmosphere (at an altitude of 0.5 km and higher) is 0 ″46, while the isoplanatic angle is 2″.47. Given the large time
constant (about 7 ms at good seeing), such conditions are favorable for using adaptive optics and interferometric measurements
in the visible and near-infrared spectral ranges.