410 research outputs found
Speaking to an imagined community. How the Paris Peace Agreements shaped ideas of the new political order in Cambodia 1992-93
Despite the importance that current peacebuilding literature assigns to internal legitimacy, we know next to nothing about the development and the negotiation of ideas in the context of an intervention: How exactly do interveners convey an image of the new political order? How do local political actors imagine the political future? What is the image they convey to their constituency? And how do converging or contradicting ideas affect the relationship between interveners and local actors and the reforms at large? Designed as a contribution to the theorization of external nation building, this work develops a theoretical framework to observe the ongoing struggles between local and international actors over the meaning of political reforms. It proposes an understanding of political authority that is tied to processes of identity formation. The analysis draws on UNTAC produced audio- and video material, the internal and public communication of its Information and Education Unit, and interviews with Cambodian politicians and former members of the large scale intervention that took place in the early 90s. Based on these materials it documents the strategies of the Transitional Authority to discipline public political discourse based on their interpretation of the Paris Peace Agreements, and the attempts of Cambodian political actors to generate political authority by confirming, rejecting, or re-interpreting their claims. Ideas of the new political order, this is the central argument, are formed as a result of this creative negotiation process
Status of the TMT site evaluation process
The Thirty Meter Telescope (TMT) is currently acquiring site characterization data at ve candidate sites.
The site testing equipment includes instruments for measuring the seeing and seeing proles, meteorological
conditions, cloudiness, precipitable water vapor, etc. All site testing equipment and data have gone through
extensive calibrations and verications in order to assure that a reliable and quantitative comparison between
the candidate sites will be possible. Here, we present an update on the status of the site selection work, the
equipment characterizations and the resulting accuracies of our site selection data
The Thirty Meter Telescope Site Conditions Monitoring System
We examine the experiences and ideas from operating observatories regarding the measurements of the characteristics of the atmosphere that must be gathered within the locality of the observatory in order to support safe, efficient and scientifically optimized observatory operations as well as commissioning, performance monitoring and support the scientific analysis of telescope observations. We describe the expected requirements for the measurement capabilities of the the TMT Site Conditions Monitoring System (SCMS) and discuss how these plans are being developed with input from staff at operating observatories and active observational astronomers
Studying the vertical extent of the ground layer turbulence using sonic-anemometers
The optical turbulence above Dome C in winter is mainly concentrated in the first tens of meters above the ground. The properties of this so-called surface layer were investigated during the last two winterover by a set of sonics anemometers placed on a 45 m high tower. These anemometers provide measurements of the temperature and the wind speed vector. The sampling rate of 10 Hz allows to derivate the refractive index structure constant C_n^2. We report here the first analysis of these data
Dome C site testing: surface layer, free atmosphere seeing and isoplanatic angle statistics
This paper analyses 3.5 years of site testing data obtained at Dome C,
Antarctica, based on measurements obtained with three DIMMs located at three
different elevations. Basic statistics of the seeing and the isoplanatic angle
are given, as well as the characteristic time of temporal fluctuations of these
two parameters, which we found to around 30 minutes at 8 m. The 3 DIMMs are
exploited as a profiler of the surface layer, and provide a robust estimation
of its statistical properties. It appears to have a very sharp upper limit
(less than 1 m). The fraction of time spent by each telescope above the top of
the surface layer permits us to deduce a median height of between 23 m and 27
m. The comparison of the different data sets led us to infer the statistical
properties of the free atmosphere seeing, with a median value of 0.36 arcsec.
The C_n^2 profile inside the surface layer is also deduced from the seeing data
obtained during the fraction of time spent by the 3 telescopes inside this
turbulence. Statistically, the surface layer, except during the 3-month summer
season, contributes to 95 percent of the total turbulence from the surface
level, thus confirming the exceptional quality of the site above it
Overcoming the boundary layer turbulence at Dome C: ground-layer adaptive optics versus tower
The unique atmospheric conditions present at sites such as Dome C on the Antarctic plateau are very favorable for high spatial resolution astronomy. At Dome C, the majority of the optical turbulence is confined to a 30 to 40 m thick stable boundary layer that results from the strong temperature inversion created by the heat exchange between the air and the ice-covered ground. To fully realize the potential of the exceptionally calm free atmosphere, this boundary layer must be overcome. In this article we compare the performance of two methods proposed to beat the boundary layer: mounting a telescope on a tower that physically puts it above the turbulent layer, and installing a telescope at ground level with a ground-layer adaptive optics system. A case is also made to combine these two methods to further improve the image quality
Gattini: a multisite campaign for the measurement of sky brightness in Antarctica
We present the Gattini project: a multisite campaign to measure the optical sky properties above the two high altitude Antarctic astronomical sites of Dome C and Dome A. The Gattini-DomeC project, part of the IRAIT site testing campaign and ongoing since January 2006, consists of two cameras for the measurement of optical sky brightness, large area cloud cover and auroral detection above the DomeC site, home of the French-Italian Concordia station. The cameras are transit in nature and are virtually identical except for the nature of the lenses. The cameras have operated successfully throughout the past two Antarctic winter seasons and here we present the first results obtained from the returned 2006 dataset. The Gattini-DomeA project will place a similar site testing facility at the highest point on the Antarctic plateau, Dome A, with observations commencing in 2008. The project forms a small part of a much larger venture coordinated by the Polar Research Institute of China as part of the International Polar Year whereby an automated site testing facility called PLATO will be traversed into the DomeA site. The status of this exciting and ambitious project with regards to the Gattini-DomeA cameras will be presented
Evaluation of sonic anemometers as highly sensitive optical turbulence measuring devices for the Thirty Meter Telescope site testing campaign
The Thirty Meter Telescope (TMT) site testing programme is evaluating the use of sonic anemometers as a means of measuring the optical turbulence at the level of its MASS/DIMM telescopes (7m). Tests were performed where sonic anemometers were directly compared against a differenced fine wire thermocouple system. We also show here that fine wire thermocouples produce turbulence measurements comparable to those from a traditional microthermal probe system
Submillimetre/TeraHertz Astronomy at Dome C with CEA filled bolometer array
Submillimetre/TeraHertz (e.g. 200, 350, 450 microns) astronomy is the prime
technique to unveil the birth and early evolution of a broad range of
astrophysical objects. A major obstacle to carry out submm observations from
ground is the atmosphere. Preliminary site testing and atmospheric transmission
models tend to demonstrate that Dome C could offer the best conditions on Earth
for submm/THz astronomy. The CAMISTIC project aims to install a filled
bolometer-array camera with 16x16 pixels on IRAIT at Dome C and explore the
200-m windows for potential ground-based observations.Comment: 6 page
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