2015
Authors
Correia, CM; Jackson, K; Veran, JP; Andersen, D; Lardiere, O; Bradley, C;
Publication
APPLIED OPTICS
Abstract
Multi-object astronomical adaptive optics (MOAO) is now a mature wide-field observation mode to enlarge the adaptive-optics-corrected field in a few specific locations over tens of arcminutes. The work-scope provided by open-loop tomography and pupil conjugation is amenable to a spatio-angular linear-quadratic-Gaussian (SA-LQG) formulation aiming to provide enhanced correction across the field with improved performance over static reconstruction methods and less stringent computational complexity scaling laws. Starting from our previous work [J. Opt. Soc. Am. A 31, 101 (2014)], we use stochastic time-progression models coupled to approximate sparse measurement operators to outline a suitable SA-LQG formulation capable of delivering near optimal correction. Under the spatio-angular framework the wavefronts are never explicitly estimated in the volume, providing considerable computational savings on 10-m-class telescopes and beyond. We find that for Raven, a 10-m-class MOAO system with two science channels, the SA-LQG improves the limiting magnitude by two stellar magnitudes when both the Strehl ratio and the ensquared energy are used as figures of merit. The sky coverage is therefore improved by a factor of similar to 5. (C) 2015 Optical Society of America
2016
Authors
Correia C.M.; Massioni P.;
Publication
Optics InfoBase Conference Papers
Abstract
Our goal is the provide a tour of recent progress towards rendering Kalman filters suitable for driving astronomical adaptive optics with increasing numbers of degrees of freedom and discuss the prospects to port them to the foreseen real-time architectures.
2016
Authors
Fusco, T; Correia, C;
Publication
2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
Abstract
2016
Authors
Piqueras, L; Jarno, A; Pecontal Rousset, A; Loupias, M; Richard, J; Schwartz, N; Fusco, T; Sauvage, JF; Neichel, B; Correia, CM;
Publication
MODELING, SYSTEMS ENGINEERING, AND PROJECT MANAGEMENT FOR ASTRONOMY VII
Abstract
This paper introduces the science software of HARMONI. The Instrument Numerical Model simulates the instrument from the optical point of view and provides synthetic exposures simulating detector readouts from data-cubes containing astrophysical scenes. The Data Reduction Software converts raw-data frames into a fully calibrated, scientifically usable data cube. We present the functionalities and the preliminary design of this software, describe some of the methods and algorithms used and highlight the challenges that we will have to face.
2016
Authors
Thatte, NAA; Clarke, F; Bryson, I; Schnetler, H; Tecza, M; Fusco, T; Bacon, RM; Richard, J; Mediavilla, E; Neichel, B; Arribas, S; García Lorenzo, B; Evans, CJ; Remillieux, A; El Madi, K; Herreros, JM; Melotte, D; O'Brien, K; Tosh, IA; Vernet, J; Hammersley, P; Ives, DJ; Finger, G; Houghton, R; Rigopoulou, D; Lynn, JD; Allen, JR; Zieleniewski, SD; Kendrew, S; Ferraro Wood, V; Pécontal Rousset, A; Kosmalski, J; Laurent, F; Loupias, M; Piqueras, L; Renault, E; Blaizot, J; Daguisé, E; Migniau, JE; Jarno, A; Bornh, A; Gallie, AM; Montgomery, DM; Henry, D; Schwartz, N; Taylor, W; Zins, G; Rodríguez Ramos, LF; Cagigas, M; Battaglia, G; López, RR; Revuelta, JSC; Rasilla, JL; Hernández Suárez, E; Gigante Ripoll, JV; López, JP; Martin, MV; Correia, C; Pascal, S; Blanco, L; Vola, P; Epinat, B; Peroux, C; Vigan, A; Dohlen, K; Sauvage, JF; Lee, M; Carlotti, A; Verinaud, C; Morris, T; Myers, R; Reeves, A; Swinbank, M; Calcines, A; Larrieu, M;
Publication
GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VI
Abstract
HARMONI is the E-ELT's first light visible and near-infrared integral field spectrograph. It will provide four different spatial scales, ranging from coarse spaxels of 60 × 30 mas best suited for seeing limited observations, to 4 mas spaxels that Nyquist sample the diffraction limited point spread function of the E-ELT at near-infrared wavelengths. Each spaxel scale may be combined with eleven spectral settings, that provide a range of spectral resolving powers (R ~3500, 7500 and 20000) and instantaneous wavelength coverage spanning the 0.5 - 2.4 µm wavelength range of the instrument. In autumn 2015, the HARMONI project started the Preliminary Design Phase, following signature of the contract to design, build, test and commission the instrument, signed between the European Southern Observatory and the UK Science and Technology Facilities Council. Crucially, the contract also includes the preliminary design of the HARMONI Laser Tomographic Adaptive Optics system. The instrument's technical specifications were finalized in the period leading up to contract signature. In this paper, we report on the first activity carried out during preliminary design, defining the baseline architecture for the system, and the trade-off studies leading up to the choice of baseline.
2016
Authors
Schwartz, N; Sauvage, JF; Neichel, B; Correia, C; Blanco, L; Fusco, T; Pecontal Rousset, A; Jarno, A; Piqueras, L; Dohlen, K; El Hadi, K; Thatte, N; Bryson, I; Clarke, F; Schnetler, H;
Publication
ADAPTIVE OPTICS SYSTEMS V
Abstract
HARMONI is a visible and near-infrared integral field spectrograph designed to be a first-light instrument on the European extremely large telescope. It will use both single-conjugate and laser tomographic adaptive optics to fully exploit high-performance and sky coverage. Using a fast AO modelling toolbox, we simulate anisoplanatism effects on the point spread function of the single-conjugate adaptive optics of HARMONI. We investigate the degradation of the correction performance with respect to the off-Axis distance in terms of Strehl ratio and ensquared energy. In addition, we analyse what impact the natural guide source magnitude, AO sampling frequency and number of sub-Apertures have on performance. We show, in addition to the expected PSF degradation with the field direction, that the PSF retains a coherent core even at large off-Axis distances. We demonstrated the large performance improvement of fine tuning the sampling frequency for dimer natural guide stars and an improvement of approx. 50% in SR can be reached above the nominal case. We show that using a smaller AO system with only 20x20 sub-Apertures it is possible to further increase performance and maintain equivalent performance even for large off-Axis angles.
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