Within the framework of the site prospection for the future European Extremely Large Telescope (E-ELT), a wide site characterization was achieved. Aklim site located at an altitude of 2350 m at the geographical coordinates: lat.= 30°07’38” N, long.= 8°18’31” W , in the Moroccan Middle Atlas Mountains, was one of the candidate sites chosen by the Framework Programme VI (FP6) of the European Union. To complete the fulfilled study (; ), we have used the ModelOTP (model of optical turbulence profiles) established by  and improved by . This model allows getting the built-in profiles of the optical turbulence under various conditions. In this paper, we present an overview of the Aklim database results, in the boundary layers and in the free atmosphere separately and we make a comparison with Cerro Pachon result .
The new Extremely Large Telescope projects need accurate evaluation of the candidate sites. In this work we present the seeing, free seeing and isoplanatic angle comparison between Aklim site located in Moroccan Anti- Atlas at the geographic coordinates 30°7'39" N, 08 18'39" W, and the Observatorio del Roque de Los Muchachos (ORM), located in La Palma, Canary Islands, at 28°45'00 N, 17°53”10 W, the both sites are pre-selected to house the E-ELT. In this work we present the seeing statistics of (Ɛ), the free seeing (Ɛ free) and the isoplanatic angle ϴ0 measurements at each site, statistics of the mentioned parameters are obtained from the whole data recorded from 09 May 2008 to 09 November 2009 using the Multi Aperture Scintillation Sensor (MASS) - Differential Image Motion Monitor (DIMM) system, compare the common data between the tow sites, more representative results and statistics are shown hereafter.
In this paper we present an analysis of the statistical and temporal properties of seeing and isoplanatic angle measurements obtained with combined Differential Image Motion Monitor (DIMM) and Multi-Aperture Scintillation Sensor (MASS) at Jbel Aklim candidate site for the Eauropean Extremely Large Telescope (E-ELT). These data have been collected from February 2008 to Jun 2010. The overall seeing statistics for Jbel Aklim site are presented, broken into total seeing, free atmosphere seeing and isoplanatic angle, and ground-layer seeing (difference between the total and free-atmosphere seeing). We examine the statistical distributions of seeing measurements and investigate annual and nightly behavior. The properties of the seeing measurements are discussed in terms of the geography and meteorological conditions at Jbel Aklim site.
We present a characterization of meteorological parameters: Wind and direction speed, temperature, relative
humidity and pressure. Data set is provided by the system of NCEP/NCAR Re-analysis. The statistical
treatment of data will cover the years between 2003 and 2006 for the Observatory Oukaïmeden. An analysis of
monthly, seasonal, and annual results is presented. We calculated the Richardson number for each month of the
year. In addition, this paper describes a comparison between balloon-sounding made at different stations and
coincident model-based meteorological analysis. The comparison allows the assessment reliability of the analysis
in studied period.
As part of the conceptual and preliminary design processes of the Extremely Large Telescope (ELT), the ELT site-testing team at Morocco has spent the last two years measuring the atmospheric properties at Aklim site as another 4 candidate mountains in North and South hemisphere, Aklim is the per-selected site for the ELT, is located in Moroccan Anti-Atlas at the geographic coordinates 30°7'39" N, 08°18'39" W.
In this paper we present the isoplanatic angle <i>θ</i><sub>0</sub> and the isopistonic angle <i>θ</i><sub>p</sub>, measurements at Aklim site, statistics of the mentioned parameters are obtained from the whole data recorded from April 2008 to December 2009 using the Multi Aperture Scintillation Sensor (MASS) - Differential Image Motion Monitor (DIMM) system, more representative results and statistics are shown hereafter.
In the framework of the E-ELT project a prospecting campaign was launched by the ESO to select the site that
will host the next generation of optical telescopes of 42 m diameter. Moroccan Anti-Atlas (Jbel Aklim) was
selected as well as other sites (ORM, Ventarrones and Macon) to be a possible potential location that will house
the E-ELT. In this paper we first present the reasons for the choice of Jbel Aklim as a E-ELT candidate through
various exploration campaigns that we have achieved. The second part concerns description of instruments used.
Finally we will present the preliminary results of the meteorological and MASS-DIMM measurements.
In this paper we describe a new technique of circular aperture apodization. It is produced by interferometry.
The light, which is diffracted by a circular aperture, is split into two beams of different amplitudes where one of
them has undergone an homothety to change its radial dimensions, by using an afocal optical system. The two
beams are then combined coherently to form an apodized point spread function (PSF). This procedure allows
us to reduce the diffraction wings of the PSF with different reduction factors depending on the combination
We present here a new approach to estimate the astronomical seeing which is a fundamental parameter in high angular resolution, in adaptive optics and site testing. Based on this approach, we developed seeing monitor, called Interferential Seeing Monitor (hereafter ISM). The principle of
the ISM is based on the study of the diffraction-interference pattern produced by a Young's double-slit in a telescope focus.
From the shape of that pattern, we determine the phase difference between the diffracted light rays that meet on the image plane. Then, the phase structure function is calculated which leads to the seeing value.