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AURA-NIO Sites Group



The AURA New Initiatives Office (NIO) , with participation from NOAO and Gemini, was formed in January 2001 to work towards the goal of starting to build a 30-m Giant Segmented Mirror Telescope (GSMT) by the end of the decade in order to complement NGST and ALMA. More than a year earlier, a CTIO-led effort began to search for a site for such a telescope, at first concentrating our efforts on Chile.  The AURA-NIO group has joined with the CELT sites group to form a Thirty Meter Telescope Sites group headed by Matthias Schoeck at Caltech.

Site-testing is difficult. Even well-funded and extensive efforts, like that of ESO for the VLT, start with an ordered list of meteorological and topographical criteria, defined by the telescope characteristics and the scientific priorities. Given a large geographical area that is in general excellent astronomically, such as the Norte Chico and Norte Grande regions of Chile, different criteria can lead to different sites. This is illustrated by the VLT site on Paranal (cloudless, good seeing) and the ALMA site on Chajnantor (low water-vapor, large flat area). If the search is widened to include other potential sites throughout the world, then the task is one of daunting magnitude.

However remote sensing techniques have greatly advanced since these early efforts, as has hydrodynamic modeling of wind-flow over topography, at a variety of scales. Use of these techniques holds the promise of dispassionate identification and comparison of sites, and easy re-evaluation if the weighting of the comparison criteria change. This approach has also been espoused by the ESO ESPAS Group in their search for a site for the 100-m OWL telescope. In parallel, we are developing equipment for in-situ site characterization, both the traditional parameters of wind, temperature, humidity, but also being able to measure, at low-resolution, the vertical turbulence profile of the atmosphere.

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NOAO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative agreement with the National Science Foundation.

Gemini is an international partnership managed by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation. Partner countries include the United States, United Kingdom, Canada, Chile, Australia, Argentina, and Brazil.
Sites rblum@ctio.noao.edu
This page last modified 2004 March