#PATHFINDER DOES BANNER EFFECT SELF FULL#

The different approaches are tested via simulation and on-sky data from two telescopes and compared to profiles obtained with the Durham Stereo-SCIDAR monitor. Different processing strategies are evaluated, including spatial segmentation and Fourier analysis.

The instrument is called FASS (Full Aperture Scintillation Sensor), as it uses the full aperture of the telescope. Using a single detector, images of the pupil (scintillation) and stars (image motion) are formed in the detector plane. We propose a novel design for a turbulence profiler. Finally, we also show that replacing the pyramid with aflattened cone also leads to very promising noise propagation properties. A first quick study of the influenceof the angle of the pyramid shows that, it is possible, with a quite constant linear range, to adjust the spatialfrequencies range where the sensitivity is the best. Furthermore, the pixel arrangement being more efficient than for the PWFS,the FPWFS seems particularly well suited for high-contrast applications. The FPWFS turns out to be more linearthan a modulated pyramid for the high-spatial order aberrations but it provides an improved sensitivity comparedto the non-modulated pyramid. In this paper thisnew WFS is compared to two existing WFSs, namely the PWFS and the Modulated PWFS (MPWFS) followingtests about sensitivity, linearity range and low photon flux behavior. This map is then used to derive the phase information. This new WFS,called the Flattened Pyramid-WFS (FPWFS), has a reduced Pyramid angle in order to optically overlap the fourpupil images into an unique intensity. We propose a new type of Wave Front Sensor (WFS) derived from the Pyramid WFS (PWFS). We demonstrate how the analysis of the spatial andtemporal PSF variations allows us to develop eective photometric techniques for MCAO to be used for the nextgeneration of large telescopes. The large number of stars allows to evaluate the performanceof the instrument in terms of position-dependent PSF. The high Strehl ratio of the images pushes the depth of the stellardetections well below the main sequence knee of the colour-magnitude diagram, making this also the deepestnear-infrared CMD yet obtained from ground. This is the most precisephotometry to date of a cluster taken from the ground, conrmed by our ability to detect the double subgiantbranch, previously observed only from space. We have observed the Galactic globular cluster NGC 1851 (and 5 other targets)and here we present the results of the prole-tting photometry in the near-infrared. GeMS on the 8-m Gemini South telescope is the rst facility-class MCAO and therst to use laser guide stars. Multi-conjugate adaptive optics is a central technology for the Extremely Large Telescopes (NFIRAOS on TMTand MAORY on E-ELT).

The formalism as well as first simulation results are presented. In a second part of this paper, we investigate an optimal way to correct for the distortion following an inverse problem approach. The accuracy of the distortion correction of an instrument is critical for its use for high- precision astrometry and photometry. In particular, GSAOI is severely a ected by distortion that can strongly degrade the resolution when combining multiple frames and can consequently reduce the sensitivity. However, despite the excellent performance of the GeMS/ GSAOI system, some variable residues are still limiting the correction quality over the field. We obtained deep JHKs images from the GeMS/ GSAOI instrument and developed reduction tools, in order to photometrically study the properties of the stellar members of the cluster and to bring new elements to our understanding of the process of massive star formation. In this paper, we first present recent observations of the young star-forming region N159W located in the Large Magellanic Cloud. The newly commissioned Gemini South Multi-Conjugate Adaptive Optics System (GeMS) combined with the infrared camera GSAOI is delivering almost di raction-limited images over a field of 2 arc-minutes across.

By using multiple Laser Guide Stars, WFAO significantly increases the field of view of the AOcorrected images, and the fraction of the sky that can benefit from such correction. The advent of a new generation of Wide Field AO (WFAO) systems marks the beginning of a new era in high spatial resolution imaging.

#PATHFINDER DOES BANNER EFFECT SELF FULL#

Pathfinder does banner effect self