Comparison of vision at mounts Maidanak, La Silla, and Paranal

Ilyasov, Sabit; Ehgamberdiev, Shuhrat A.; Sarazin, M.; Tillayev, Yusufjon

doi:10.1117/12.370550

Cited by 4 publications

(3 citation statements)

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“…The same tendency has been registered at Observatorio del Roque de los Muchachos (ORM) by Muñon‐Tuñon, Vernin & Varela (1997) and García‐Lorenzo et al (2009). In addition, the high‐altitude wind speed statistics has been already used as a parameter for ranking for AO (Ilyasov, Tillayev & Ehgamberdiev 2000; Sarazin 2002; Carrasco & Sarazin 2003; Chueca et al 2003; Carrasco, Avila & Carramiñana 2005; García‐Lorenzo et al 2005; Bounhir et al 2009). On the basis of Sarazin & Tokovinin (2002) relationship, it becomes necessary to find a relation between and specific to each astronomical site because of differences in the vertical wind speed distributions.…”

Section: Introductionmentioning

confidence: 57%

Meteorological profiles and optical turbulence in the free atmosphere with NCEP/NCAR data at Oukaïmeden - I. Meteorological parameters analysis and tropospheric wind regimes

Hach¹,

Jabiri²,

Ziad³

et al. 2011

Monthly Notices of the Royal Astronomical Society

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In this paper, we have used the National Centers for Environmental Prediction (NCEP)/National Centers for Atmospheric Research (NCAR) Reanalysis data base to study, first, a comparison between balloon sounding made at different stations with coinciding model‐based meteorological analysis. The comparison allows the assessment of reliability of the analysis in the studied period and to highlight NCEP/NCAR Reanalysis as an interesting data base for site characterization. Using the same system of Reanalysis, we present, secondly, the first complete characterization of main meteorological parameters at Oukaïmeden Observatory: wind speed, its direction, temperature and pressure. The statistical treatment of data will cover the years between 1990 and 2009. Monthly, seasonal and annual results are analysed. The comprehensive and reliable statistics of tropospheric wind speeds at Oukaïmeden are presented. We found a clear annual periodicity of 200 mbar wind speed. This periodicity could be related to the seasonal dependence of seeing that is affected by the existence of cloud sea during the period around autumn–winter and by high wind speed regimes during spring. The connection of high‐ to low‐altitude tropospheric winds has been explored. We found a high correlation comparable to the ones found at La Silla and La Palma sites. The local parameters in particular topography and stratocumulus formations might affect 700 mbar wind roses. Richardson numbers calculated for each month at Oukaïmeden and La Palma are presented. By analysing the values, we found out that the periods and the regions of development of turbulence in relative terms of stability for the two locations are very similar. In addition, we present the first example of a profile estimated from NCEP/NCAR Reanalysis. We found that this profile presents a tendency very similar to the same averaged profile measured by the balloon‐born radiosondes.

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Section: Introductionmentioning

confidence: 57%

Meteorological profiles and optical turbulence in the free atmosphere with NCEP/NCAR data at Oukaïmeden - I. Meteorological parameters analysis and tropospheric wind regimes

Hach¹,

Jabiri²,

Ziad³

et al. 2011

Monthly Notices of the Royal Astronomical Society

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“…Henceforward, the problem could be reduced to determining statistics for the existing worldwide long‐term high‐altitude winds data in climatological data bases. Indeed, V 200 statistics has been already used as a parameter for ranking astronomical sites for their suitability for AO (Ilyasov, Tillayev & Ehgamberdiev 2000; Sarazin 2002; Carrasco & Sarazin 2003; Chueca et al 2004; Carrasco, Ávila & Carramiñana 2005; García‐Lorenzo et al 2005; Bounhir, Benkhaldoun & Sarazin 2008).…”

Section: Introductionmentioning

confidence: 99%

Adaptive optics parameters connection to wind speed at the Teide Observatory

García-Lorenzo

Eff-Darwich

Fuensalida

et al. 2009

Monthly Notices of the Royal Astronomical Society

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Current projects for large telescopes demand a proper knowledge of atmospheric turbulence to design efficient adaptive optics systems in order to reach large Strehl ratios. However, the proper characterization of the turbulence above a particular site requires long-term monitoring. Because of the lack of long-term information on turbulence, high-altitude winds (in particular winds at the 200 mbar pressure level) were proposed as a parameter for estimating the total turbulence at a particular site, with the advantage of records of winds going back several decades. We present the first complete study of atmospheric adaptive optics parameters above the Teide Observatory (Canary Islands, Spain) in relation to wind speed. On-site measurements of C 2 N (h) profiles (more than 20 200 turbulence profiles) from G-SCIDAR (Generalized Scintillation Detection and Ranging) observations and wind vertical profiles from balloons have been used to calculate the seeing, the isoplanatic angle and the coherence time. The connection of these parameters to wind speeds at ground and at 200 mbar pressure level are shown and discussed. Our results confirm the well-known high quality of the Canary Islands astronomical observatories.

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“…7 Various parameters of the atmosphere that influence astronomical image quality in optics were studied. These include seeing in comparison with La Silla and Paranal Observatories, 8 high-altitude wind speed, 9 optical turbulence in the free atmosphere 10 as well as extinction. 11 The nigh-time seeing was measured with the European Southern Observatory differential image motion monitor (DIMM).…”

Section: Introductionmentioning

confidence: 99%

Astronomical seeing at Maidanak Observatory with differential image motion monitor

Azimov

Tillayev

Ehgamberdiev

et al. 2022

J. Astron. Telesc. Instrum. Syst.

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The article presents statistics of the astronomical seeing at the Maidanak Observatory in Uzbekistan. Astronomical seeing measurements were performed using a differential image motion monitor. In the period 2018 to 2021, a total number of 204 night observations were carried out. The median zenith seeing for the entire period of observations was found to be 0.69″ (arcseconds). The results were compared with those obtained in the previous measurement period of 1996 to 2003. The comparison shows very small differences between the two measurement sets in the monthly and yearly median values. The best seeing was observed in October, but it was November according to the previous measurements. The best year in terms of seeing was 2019 with its median value 0.65″ and the worst seeing observed in 2021 (0.71″).

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Comparison of vision at mounts Maidanak, La Silla, and Paranal

Cited by 4 publications

References 0 publications

Meteorological profiles and optical turbulence in the free atmosphere with NCEP/NCAR data at Oukaïmeden - I. Meteorological parameters analysis and tropospheric wind regimes

Meteorological profiles and optical turbulence in the free atmosphere with NCEP/NCAR data at Oukaïmeden - I. Meteorological parameters analysis and tropospheric wind regimes

Adaptive optics parameters connection to wind speed at the Teide Observatory

Astronomical seeing at Maidanak Observatory with differential image motion monitor

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