This will count as one of your downloads.
You will have access to both the presentation and article (if available).
MAORY stands for Multi-conjugate Adaptive Optics RelaY (the name has been recently changed to MORFEO, which stands for Multiconjugate adaptive Optics For ELT Observations, thus in this article we will use MORFEO), and it is one of the instruments of the European Extremely Large Telescope (ELT). The main function of MORFEO is to relay the light beam from the ELT focal plane to the client instrument (initially MICADO) while compensating, through a multiconjugate adaptive optics system, the effects of the atmospheric turbulence and other disturbances affecting the wavefronts coming from the scientific sources of interest.
The MORFEO instrument is designed and developed by a European consortium composed of INAF (Istituto Nazionale di AstroFisica, Italy), CNRS/INSU (Centre National de la Recherche Scientifique/ Institut National des Sciences de l’Univers, France), NUIG (National University of Ireland Galway, Ireland) and ESO (European Southern Observatory, Europe).
The opto-mechanical design of MORFEO has been developed in 3 dimensions, using the volume between the ELT output focal plane and the Nasmyth floor. The design uses the available volume in a very efficient way, but this poses constraints on the orientation of the optical elements and adds complexity to the AIT operations. In this paper we describe the strategy of the AIT process which will be performed at INAF-OAS Bologna (Italy), which is conceived to maximize knowledge of the instrument and thereby optimize (and, possibly, minimize) the time requested at Armazones for the AIV operations.
The residual speckles1, 2 set the most serious limitation in the detection of exo-planets in high contrast coronographic images provided by instruments such as SPHERE3 at the VLT, GPI4, 5 at Gemini, or SCExAO6 at Subaru. A number of post-processing methods have been proposed to remove as much as possible of the residual speckles while preserving the signal from the planets. These methods exploit the fact that the speckles and the planetary signal have different temporal and spectral behaviors. Some methods like LOCI7 are based on angular differential imaging8 (ADI), spectral differential imaging9, 10 (SDI), or on a combination of ADI and SDI.11 Instead of working on image differences, we propose to tackle the exo-planet detection as an inverse problem where a model of the residual speckles is fit on the set of multi-spectral images and, possibly, multiple exposures. In order to reduce the number of degrees of freedom, we impose specific constraints on the spatio-spectral distribution of stellar speckles. These constraints are deduced from a multi-spectral Taylor series expansion of the diffraction pattern for an on-axis source which implies that the speckles are a combination of spatial modes with deterministic chromatic magnification and weighting. Using simulated data, the efficiency of speckle removal by fitting the proposed multi-spectral model is compared to the result of using an approximation based on the singular value decomposition of the rescaled images. We show how the difficult problem to fitting a bilinear model on the can be solved in practise. The results are promising for further developments including application to real data and joint planet detection in multi-variate data (multi-spectral and multiple exposures images).
APE: a breadboard to evaluate new phasing technologies for a future European Giant Optical Telescope
View contact details
No SPIE Account? Create one
