Recent seeing measurements at the Anglo-Australian Telescope (AAT) point towards the thermal characteristics of the telescope itself, in particular the temperature difference between the mirror and the dome air, as the most important factor degrading the seeing, more so than the temperature difference between the inside and outside air. We present the findings, propose clarifying experiments, and discuss possible remedies. We set the realistic target for the AAT to achieve median seeing of 1·5″ rather than the current 1·8″.

Seeing measured in the open air with a differential image motion monitor (DIMM) is compared with seeing measured simultaneously at the Cassegrain focus of the Anglo-Australian Telescope (AAT). It is shown that when the mirror is hotter than the dome air, the AAT’s seeing is degraded by ~1 arcsec per Celsius degree of excess mirror temperature. The consequence of this is that mirror seeing currently contributes significantly to the seeing at the AAT on many nights. A mirror colder than the dome air does not seem to degrade seeing, and neither does an internal-to-external air temperature difference of up to at least 3°C when the venting fans are on.

Site-testing measurements by the Australian group has already shown that Dome C on the Antarctic plateau is one of the best ground-based astronomical sites. Furthermore, Dome A, the Antarctic Kunlun Station, as the highest point on Antarctic inland plateau, where a Chinese Antarctic scientific expedition team first reached in 2005, is widely predicted to be an even better astronomical site by the international astronomical community. Preliminary site-testing carried out by the Center for Antarctic Astronomy (CAS) also confirms Dome A as a potential astronomical site. Multi-aperture scintillation sensors (MASS) can measure the seeing and isoplantic angle, the turbulence profile, etc., which are very important site-testing parameters that we urgently need. The MASS site testing at Dome A is presented here, and includes the method of processing data and the hardware for the extreme conditions of Dome A, Antarctica.

From theoretical analysis and site testing work for 4 years on Dome A, Antarctica, we can reasonably predict that it is a very good astronomical site, as good as or even better than Dome C and suitable for observations ranging from optical to infrared & sub-mm wavelengths. After the Chinese Small Telescope ARray (CSTAR), which was composed of four small fixed telescopes with diameter of 145mm and the three Antarctic Survey Telescopes (AST3) with 500mm entrance diameter, the Kunlun Dark Universe Survey Telescope (KDUST) with diameter of 2.5m is proposed. KDUST will adopt an innovative optical system which can deliver very good image quality over a 2 square degree flat field of view. Some other features are: a fixed focus suitable for different instruments, active optics for miscollimation correction, a lens-prisms that can be used as an atmospheric dispersion corrector or as a very low-dispersion spectrometer when moved in / out of the main optical path without changing the performance of the system, and a compact structure to make easier transportation to Dome A. KDUST will be mounted on a tower with height 15m in order to make a full use of the superb free atmospheric seeing.

Sites on Antarctic plateau have unique atmospheric properties that make them better than any mid-latitude sites as observatory locations. From site testing measurements over 4 years on Dome A carried out by the Chinese Center for Antarctic Astronomy, we can reasonably predict that Dome A is as good as or even better than Dome C, which has been proved to be the best astronomical site by now, and suitable for high angular resolution observations. Seeing monitoring is necessary for planning large scale ground-based optical astronomical telescopes. In 2012, the 28th Chinese Antarctic Scientific Expedition carried out preliminary daytime seeing monitoring using a Differential Image Motion Monitor (DIMM) placed at a height of 3.5m. The median seeing was found to be 0.8″. This will be the foundation of future research that obtains comprehensive and long-period monitoring of the site's optical parameters.

Vision is used in nearly all aspects of animal behavior, from prey and predator detection to mate selection and parental care. However, the light environment typically is not uniform in every direction, and visual tasks may be specific to particular parts of an animal’s field of view. These spatial differences may explain the presence of several adaptations in the eyes of vertebrates that alter spectral sensitivity of the eye in different directions. Mechanisms that alter spectral sensitivity across the retina include (but are not limited to) variations in: corneal filters, oil droplets, macula lutea, tapeta, chromophore ratios, photoreceptor classes, and opsin expression. The resultant variations in spectral sensitivity across the retina are referred to as intraretinal variability in spectral sensitivity (IVSS). At first considered an obscure and rare phenomenon, it is becoming clear that IVSS is widespread among all vertebrates, and examples have been found from every major group. This review will describe the mechanisms mediating differences in spectral sensitivity, which are in general well understood, as well as explore the functional significance of intraretinal variability, which for the most part is unclear at best.

The limitation to ground based astronomy is the Earth's atmosphere. The atmosphere above the Antarctic plateau is fundamentally different in many regards compared to the atmosphere at temperate sites. The extreme altitude, cold and low humidity offer a uniquely transparent atmosphere at many wavelengths. Studies at the South Pole have shown additionally that the turbulence properties of the night time polar atmosphere are unlike any mid latitude sites. The lack of high altitude turbulence combined with low wind speeds presents favorable conditions for interferometry. More recent site testing at Dome C has revealed the most superb seeing of any site tested. The unique properties of the polar atmosphere can be exploited for Extra-solar Planet studies with differential astrometry, differential phase and nulling interferometers.

A variety of observations have been made of solar features (sunspots, faculae, the limb) using both array and single element scanning techniques. The telescope was the 1.6 m McMath-Pierce on Kitt Peak. Array data were acquired with a 58×62 pixel Si:Ga detector at 4.8, 7.8, 12.4, and 18 μm, while a CCD camera recorded the same image position at 0.5 μm. In a separate experiment, a nutating mirror device was used to generate a raster scan of solar disk areas, the output being fed to a Si PIN diode (0.5 μm filter) and a As:Si diode (12.4 μm filter). The scanner data yield simultaneous images at the two wavelengths and was essentially a repeat of the 1970 Turon-Léna experiment with updated equipment. Examples of images at the various wavelengths are given in the poster. Analysis of the data is incomplete at this time. We can report that the effects of seeing were encountered at all wavelengths, including 18μm, even though conditions were deemed good at times (for example, penumbral filaments were resolved in sunspots). We have thus been unable to verify, as yet, the conditions reported by Bester et al, in which exceptional seeing is realized in the infrared.

Adaptive optics systems are now being developed for astronomical applications. On large telescopes, a substantial image improvement can be obtained in the near infrared, using natural guide stars.