AST3-NIR is a new infrared camera for deployment with the AST3-3 wide-field survey telescope to Dome A on the Antarctic plateau. This project is designed to take advantage of the low Antarctic infrared sky thermal background (particularly within the K<sub>dark</sub> near infrared atmospheric window at 2.4 μm) and the long Antarctic nights to provide high sensitivity temporal data from astronomical sources. The data collected from the Kunlun Infrared Sky Survey (KISS) will be used to conduct a range of astronomical science cases including the study of supernovae, exo-planets, variable stars, and the cosmic infrared background.
We have developed Water Vapour Radiometers (WVRs) for the Australia Telescope Compact Array that are capable of determining excess path fluctuations by virtue of measuring small temperature fluctuations in the atmosphere using the 22.3 GHz water vapour line for each of the six antennae. By measuring the line of sight variations of the water vapour, the induced path excess and thus the phase delay can be estimated and corrections can then be applied during data reduction. This reduces decorrelation of the source signal. In this presentation, we discuss the design of the WVRs, an uncooled quadruple filter radiometer capable of detecting water line temperature fluctuations to a sensitivity of 12 mK. The design process of the WVRs is discussed with an emphasis on the modelled sensitivity requirements, filter placement, radio frequency interference mitigation and we conclude by demonstrating how this water vapour radiometry system recovers the telescope's efficiency and image quality as well as how this improves the telescope's ability to use longer baselines at higher frequencies, thereby resulting in higher spatial resolution. We discuss a quadruple filter, uncooled 22.2 GHz Water Vapour Radiometer (WVR) system developed for the six antennae of the Australia Telescope Compact Array. The design process of the WVRs is discussed with an emphasis on the modelled sensitivity requirements, filter placement, radio frequency interference mitigation and we conclude by demonstrating how this system recovers the telescope's efficiency and image quality as well as how this improves the telescope's ability to use longer baselines at higher frequencies, thereby resulting in higher spatial resolution.
PLATO-R is an autonomous, robotic observatory that can be deployed anywhere on the Antarctic plateau by Twin Otter
aircraft. It provides heat, data acquisition, communications, and up to 1kW of electric power to support astronomical and
other experiments throughout the year. PLATO-R was deployed in 2012 January to Ridge A, believed to be the site with
the lowest precipitable water vapour (and hence the best atmospheric transmission at terahertz frequencies) on earth.<sup>1-4</sup>
PLATO-R improves upon previous PLATO designs that were built into ten-foot shipping containers by being much smaller
and lighter, allowing it to be field-deployable within 2-3 days by a crew of four.
PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed Australian/European optical/infrared
telescope for Dome C on the Antarctic Plateau, with target first light in 2012. The proposed telescope is 2.4m diameter,
with overall focal ratio f/10, and a 1 degree field-of-view. In median seeing conditions, it delivers 0.3" FWHM wide-field
image quality, from 0.7-2.5 microns. In the best quartile of conditions, it delivers diffraction-limited imaging down
to 1 micron, or even less with lucky imaging. The areas where PILOT offers the greatest advantages are (a) very high
resolution optical imaging, (b) high resolution wide-field optical imaging, and (c) all wide-field thermal infrared
imaging. The proposed first generation instrumentation consists of (a) a fast, low-noise camera for diffraction-limited
optical lucky imaging; (b) a gigapixel optical camera for
seeing-limited imaging over a 1 degree field; (c) a 4K x 4K
near-infrared (1-5 micron) camera with both wide-field and diffraction-limited modes; and (d) a double-beamed midinfrared
(7-40 micron) camera.
We present a proposal for an 8.4 metre off-axis optical/IR telescope to be located at Dome C, Antarctica. LAPCAT will use a mirror identical to the offset segment recently cast for the Giant Magellan Telescope (GMT) as a completely unobscured f/2.1 primary. With a cooled deformable Gregorian secondary in a dewar following prime focus, LAPCAT will allow for diffraction-limited imaging with only a single reflecting surface at ~220K, and thus the lowest possible thermal background obtainable on earth. The exceptionally low atmospheric turbulence above Dome C enables very high contrast imaging in the thermal infrared, and diffraction limited imaging extending to optical wavelengths (20 mas at 800 nm, where Strehl ratios > 60% are projected). As an example, a deep 5 μm exoplanet imaging survey to complement current radial velocity methods could take advantage of both the low background and pupil remapping methods for apodization enabled by the clear aperture. Many new, young, giant planets (≥ 3M<sub>J</sub> at 1 Gyr) would be detected in orbits ≥ 5 AU out to 20 pc. By providing a test bed for many of the GMT technologies in an Antarctic environment, LAPCAT also paves the way for the eventual construction of a second GMT at Dome C. Such a telescope would have unparalleled capabilities compared both to other ELTs in temperate sites and to JWST.
Recent data have shown that Dome C, on the Antarctic plateau, is an exceptional site for astronomy, with atmospheric
conditions superior to those at any existing mid-latitude site. Dome C, however, may not be the best site on the
Antarctic plateau for every kind of astronomy. The highest point of the plateau is Dome A, some 800 m higher than
Dome C. It should experience colder atmospheric temperatures, lower wind speeds, and a turbulent boundary layer that
is confined closer to the ground. The Dome A site was first visited in January 2005 via an overland traverse, conducted
by the Polar Research Institute of China. The PRIC plans to return to the site to establish a permanently manned station
within the next decade. The University of New South Wales, in collaboration with a number of international institutions,
is currently developing a remote automated site testing observatory for deployment to Dome A in the 2007/8 austral
summer as part of the International Polar Year. This self-powered observatory will be equipped with a suite of site
testing instruments measuring turbulence, optical and infrared sky background, and sub-millimetre transparency. We
present here a discussion of the objectives of the site testing campaign and the planned configuration of the observatory.
The Antarctic Fiber-Optic Spectrometer (AFOS) is a 30cm Newtonian optical telescope that injects light through six 30m long optical fibers onto a 240-850nm spectrograph with a 1024 x 256 pixel CCD camera. The telescope is mounted on a dual telescope altitude-azimuth mount and has been designed to measure the transperency of the atmosphere above the South Pole for astronomy in the UV and visible wavelength regions. The instrument has observed a series of bright O and B stars during the austral winters of 2002 and 2003 to probe the UV cutoff wavelength, the auroral intensity and water vapour content in the atmosphere above the plateau. AFOS is the first completely automated optical telescope on the Antarctic Plateau. This paper reports on the results of the past two austral winters of remote observing with the telescope as well as the technical and software modifications required to improve the quality and automation of the observations. The atmospheric absorption bands in the 660-900nm regions of the spectra have been fitted with MODTRAN atmospheric models and used to calculate the precipitable water vapour above the South Pole. These data are then compared to those collected concurrently by radiosonde and by a 350 μm submillimeter tipper at South Pole.
An important parameter that defines the effectiveness and efficiency of any optical or infrared sky survey is the atmospheric character of the observing site. Of prime importance is the sky spectral brightness, which determines the sensitivities and the observing time required to complete a particular survey. This paper presents observations of the near-infrared sky spectral brightness measured at the South Pole throughout the 2001 winter with an automated instrument, the Near Infrared Sky Monitor (NISM). Results from the NISM confirm that the South Pole sky spectral brightness is up to two orders of magnitude lower than at any other ground-based site, consistent with previous observations. These results indicate that the Antarctic plateau is an ideal place to site a future infrared sky survey telescope.
The Douglas Mawson Telescope (DMT) is a proposed 2 m telescope to be situated on the Antarctic plateau. The proposal comes from Australia, and invites participation by other nations, especially those already active in Antarctic astronomy; such as Italy, France and the United States. The DMT will be equipped with instrumentation to perform wide-field imaging from the near to far infrared. Results from an extensive site testing campaign over the last decade indicates that an Antarctic infrared telescope can be one to two orders of magnitude more sensitive than any other ground based telescope of the same size. The DMT will be an important tool for astrophysical research. It will also be beneficial as a technological test bed for future large (8-10 m class) Antarctic telescopes and interferometers, and for space-based telescopes. This paper analyses the performance of the DMT in terms of the achievable resolution, field-of-view, sensitivity and survey depth and compares it to a similar sized telescope located with the characteristic mid-latitude atmosphere of Mauna Kea.
In the coming decades, astronomical breakthroughs will increasingly come from observations from the best ground-based locations and from space observatories. At infrared and sub-millimetre wavelengths in particular, Antarctica offers site conditions that are found nowhere else on earth. There are two implications of this. First, for tackling some of the most crucial problems in astrophysics, a large telescope in Antarctica can outperform any other ground-based facility. Second, with infrared backgrounds between one and two orders of magnitude below those at other sites, superior sub-mm transmission and extraordinary low atmospheric turbulence above the boundary layer, Antartical offers designers of space missions a unique test-bed for their ideas and instrumentation.
In order to fully characterize the astronomical potential of remote sites on the antarctic plateau, we have developed a suite of instruments covering UV to sub-millimeter wavelengths. In addition, we have successfully demonstrated the use of an acoustic radar at the South Pole to measure the height of the turbulent atmospheric boundary layer. Each instrument is designed to operate independently and autonomously, producing reliable, fully calibrated data without human intervention. Although designed primarily for use in Antarctica, these instrument use novel technology that is applicable to other astronomical applications as well.
Over the past few years, site-testing at the South Pole has revealed conditions that are uniquely favorable for IR astronomy. In particular, the exceptionally low sky brightness throughout the near- and mid-IR leads to the possibility of a modest-sized telescope achieving comparable sensitivity to that of existing 8-10 meter class telescopes. An 8m Antarctic telescope, if constructed, would yield performance that would be unrivaled until the advent of the NGST. In this paper we review the scientific potential of IR telescopes in Antarctica, and discuss their complementarity with existing 8-10m class telescopes.
We discuss the site conditions for astronomy at the South Pole and over the Antarctic plateau. We find that these conditions are the most favorable on Earth for sensitive observations at thermal IR and sub-millimeter wavelengths. We further discuss plans to develop IR facilities to exploit this potential.
We describe an imaging Fabry-Perot instrument, and give examples of its astronomical applications. The salient features of the instrument are: wide wavelength coverage with a single etalon, operation near the focal plane in a converging beam, resolving power R approximately 4000, relatively easy portability to other telescopes.
The Antarctic plateau has the potential for being the best site on Earth for conducting astronomical observations from the near-infrared to the sub-millimeter. Particular gains are expected in the 1 to 5 micron region, where the high altitude, low water vapor content, and low thermal emission from the atmosphere combine to create observing conditions unequalled elsewhere on the surface of the earth. We describe an instrument, the infrared photometer- spectrometer (IRPS), that we are using to quantify site conditions at the South Pole by measuring the near-infrared sky brightness. We also describe some of the unique problems associated with building instruments to work in Antarctica.