PDM13 is a new graphic interface program dedicated to frequency domain analysis based on the Phase Dispersion Minimization technique (PDM, Stellingwerf 2012). In this paper, we will present the different algorithms running in PDM13, including the Auto-Segmentation, the Gauss-Newton and the PDM algorithms. More details on this triptych are available in our recent paper (Zalian et al., submitted). Their aim is to offer a simple and powerful way to extract frequency. Amongst the numerous improvements offered by the program, we will particularly focus on the reduction of aliases and the ability to look directly for multiple-period phenomena and the Blazhko effect. After that, we will show the first results from PDM13 using the Antarctica photometric survey.

This paper introduces a plan to detect turbulence profiles at Dome A with a Single Star Scidar (SSS), to enhance our understanding of the characteristics of the site. The development of a portable monitor for profiling vertical atmospheric optical turbulence and wind speed is presented. By analyzing the spatial auto and cross-correlation functions of very short exposure images of single star scintillation patterns, the SSS can provide the vertical profiles of turbulence intensity C2n(h) and wind speed V(h). A SSS prototype is already operational at Ali in Tibet which will be improved in order to become fully robotic and adapted to extreme weather conditions that prevail at Dome A in Antarctica.

In the recent years, a lot of instruments have been put into operation during the polar summer at DômeC., Then, during the first polar night when the Astro-Concordia sation was open for the first time during winter, about 40 balloons (Azouit & Vernin) instrumented to measure optical turbulence profiles and 2 Differencial Image Motion Monitors (DIMM) were setup. The main results from this first important campaign are found in Agabi et al. (2006). It appears from this first night time observations that almost all the optical turbulence was concentrated in the first 30 m above the ice. At an elevation of 8.5 m above the ice the seeing is about 1″.4, while above an elevation of 30 m the seeing drops down to 0″.36. This last figure is coherent with the estimation from Lawrence et al. (2004) if one takes into account that they were not sensitive to the first 30 m., which corresponds to the turbulent surface layer.

The idea of starting an astronomical site testing in Antarctica began during a congress organized by French Académie des Sciences, in 1992, and entitled ‘Recherches polaires-Une Stratégie pour l'an 2000’. At this time, one of us (Vernin 1994) gave a proposal for an astronomical site testing in Antarctica. This proposal was rapidly followed by a meeting between Al Harper (from ‘Center for Astrophysical Research in Antarctica’, Chicago), Peter Gillingham (from the Anglo Australian Observatory, Australia) and Jean Vernin (from Nice University) at Lake Geneva, Wisconsin, in 1993. It was decided to investigate what was the astronomical quality of South Pole station, each institute bringing its own participation: CARA, the South Pole infrastructure, University of New South Wales, a PhD student and Nice University its expertise and instruments.

For the first time important irregularities in atmospheric pulsations of RR Lyrae itself are clearly detected. They occur from one pulsation cycle to another. Their origins cannot be directly explained by the Blazhko effect. We suggest that these irregularities are mostly provoked by strong shock waves propagating within the atmosphere.