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One of the primary scientific limitations of adaptive optics (AO) has been the incomplete knowledge of the point spread function (PSF), which has made it difficult to use AO for accurate photometry and astrometry in both crowded and sparse fields, for extracting intrinsic morphologies and spatially resolved kinematics, and for detecting faint sources in the presence of brighter sources. To address this we initiated a program to determine and demonstrate PSF determination for science observations obtained with Keck AO. This paper aims to give a broad view of the progress achieved in implementing this capability for Keck AO science observations.The concept and the implementation are briefly described. The design and development of prototype operational tools for automated PSF reconstruction is presented in detail. On-sky performance of the technique is discussed by comparing the reconstructed PSFs to the NIRC2 science camera’s PSFs. The PSF algorithm development for this program is presented in this conference in a separate paper (Jolissaint et al. 2016).

The high control frequency required of planned E-ELT adaptive optics modules (from several hundreds of Hz tothousands and typically in the region of 500 Hz for first light E-ELT instruments such as HARMONI), along withthe high number of actuators, leads to very demanding computational needs for the real-time AO control (RTC)systems. The number of actuators, proportional the total area of the telescope primary mirror, will range fromseveral thousands to tens of thousands (typically 4-6 thousand for first light E-ELT instruments). TraditionalRTC architectures based on CPU only technologies are typically unable to achieve the required performancein a cost-effective and maintainable manner. Alternative hardware such as many-core hardware acceleratorsneed to be considered to deliver the computational power. These many-core processors offering a highly parallelenvironment, have the potential of coping with the high computational load and of accelerating parts of the AOcontrol loop. AO systems for the E-ELT however, also put heavy constrains on acceptable levels of jitter andlatency.In this paper, we investigate novel hardware that has the potential to accelerate wavefront reconstruction andwavefront pre-processing, respectively the Intel Xeon Phi and the TILERA TILE-Gx processors. We present adetailed performance analysis putting an emphasis on execution time, jitter (i.e. variation in execution time)and outliers (i.e. results significantly apart from mean). Results are explored both for specific first light E-ELTinstruments and, to stay as general as possible and fully appreciate scalability issues, for a much wider range ofAO system sizes. The paper also addresses anticipated near future hardware developments and examines theirsuitability for the E-ELT.

The advent of a new generation of Wide Field AO (WFAO) systems marks the beginning of a new era in high spatial resolution imaging. 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 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. In this paper, we first present recent observations of the young star-forming region N159W located in the Large Magellanic Cloud. 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. However, despite the excellent performance of the GeMS/ GSAOI system, some variable residues are still limiting the correction quality over the field. 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. The accuracy of the distortion correction of an instrument is critical for its use for high- precision astrometry and photometry. In a second part of this paper, we investigate an optimal way to correct for the distortion following an inverse problem approach. The formalism as well as first simulation results are presented.

The advent of a new generation of Wide Field AO (WFAO) systems marks the beginning of a new era in high spatial resolution imaging. 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 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. In this paper, we first present recent observations of the young star-forming region N159W located in the Large Magellanic Cloud. 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. However, despite the excellent performance of the GeMS/ GSAOI system, some variable residues are still limiting the correction quality over the field. 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. The accuracy of the distortion correction of an instrument is critical for its use for high- precision astrometry and photometry. In a second part of this paper, we investigate an optimal way to correct for the distortion following an inverse problem approach. The formalism as well as first simulation results are presented.

The high control frequency required of planned E-ELT adaptive optics modules (from several hundreds of Hz tothousands and typically in the region of 500 Hz for first light E-ELT instruments such as HARMONI), along withthe high number of actuators, leads to very demanding computational needs for the real-time AO control (RTC)systems. The number of actuators, proportional the total area of the telescope primary mirror, will range fromseveral thousands to tens of thousands (typically 4-6 thousand for first light E-ELT instruments). TraditionalRTC architectures based on CPU only technologies are typically unable to achieve the required performancein a cost-effective and maintainable manner. Alternative hardware such as many-core hardware acceleratorsneed to be considered to deliver the computational power. These many-core processors offering a highly parallelenvironment, have the potential of coping with the high computational load and of accelerating parts of the AOcontrol loop. AO systems for the E-ELT however, also put heavy constrains on acceptable levels of jitter andlatency.In this paper, we investigate novel hardware that has the potential to accelerate wavefront reconstruction andwavefront pre-processing, respectively the Intel Xeon Phi and the TILERA TILE-Gx processors. We present adetailed performance analysis putting an emphasis on execution time, jitter (i.e. variation in execution time)and outliers (i.e. results significantly apart from mean). Results are explored both for specific first light E-ELTinstruments and, to stay as general as possible and fully appreciate scalability issues, for a much wider range ofAO system sizes. The paper also addresses anticipated near future hardware developments and examines theirsuitability for the E-ELT.

One of the primary scientific limitations of adaptive optics (AO) has been the incomplete knowledge of the point spread function (PSF), which has made it difficult to use AO for accurate photometry and astrometry in both crowded and sparse fields, for extracting intrinsic morphologies and spatially resolved kinematics, and for detecting faint sources in the presence of brighter sources. To address this we initiated a program to determine and demonstrate PSF determination for science observations obtained with Keck AO. This paper aims to give a broad view of the progress achieved in implementing this capability for Keck AO science observations.The concept and the implementation are briefly described. The design and development of prototype operational tools for automated PSF reconstruction is presented in detail. On-sky performance of the technique is discussed by comparing the reconstructed PSFs to the NIRC2 science camera’s PSFs. The PSF algorithm development for this program is presented in this conference in a separate paper (Jolissaint et al. 2016).

ARGOS is the laser guide star facility of the Large Binocular Telescope (LBT). It implements a Rayleigh Laser Guide Star system that provides Ground Layer Adaptive Optics (GLAO) correction for the LUCIs, the 2 wide- field near-infrared imagers and multi-object spectrographs installed on the 2 eyes of LBT. In this paper we describe how LBT’s adaptive optics operations have been tailored to ARGOS’s use cases based on the experience developed during over the ARGOS commissioning. We focus on all the aspects that are influenced by the use of the Laser Guide Stars, from collimation to acquisition and LGS guiding and we details the sequences to start, pause and resume the adaptive correction.

The laser guide star (LGS) adaptive optics (AO) system on the Keck II telescope has been upgraded with a Center Launch Laser System (CLS) and a next generation laser (NGL; i.e. a TOPTICA/MPBC laser) is being implemented. The purpose of the CLS upgrade is to improve the performance of the existing Keck II LGS AO system by reducing the perspective elongation of the LGS as seen by the AO wavefront sensor and hence the measurement error, one of the largest terms in the current error budget. This performance improvement is achieved by projecting the laser from behind the Keck telescope’s secondary mirror instead of from the side of the Keck telescope. The purpose of the NGL upgrade is to increase the laser return and improve laser operability for science operation. The higher return from the NGL would open up new possibilities for further AO upgrades such as a laser asterism to reduce the focal anisoplanatism, and to increase the wavefront sensor (WFS) sampling rate to reduce the bandwidth error in addition to reducing the measurement error.The CLS transitioned to science operation in June 2015. The NGL with the CLS had first light on Dec. 1, 2015 and is being optimized to support transitioning to science operations in April 2016. This paper provides an overview of the design, implementation and on-sky performance of the new launch system and laser. The results are discussed in the context of AO for extremely large telescopes.

We present in this paper preliminary simulation results aimed at validating the GMT piston control strategy. Wewill in particular consider an observing mode in which an Adaptive Optics (AO) system is providing fast on-axisWF correction with the Adaptive Secondary Mirror (ASM), while the phasing system using multiple SegmentPiston Sensors (SPS) makes sure that the seven GMT segments remain phased. Simulations have been performedwith the Dynamic Optical Simulation (DOS) tool developed at the GMT Project Oce, which integrates theoptical and mechanical models of GMT. DOS fast ray-tracing capabilities allows us to properly simulate theeect of eld-dependent aberrations, and in particular, the so-called Field Dependent Segment Piston (FDSP)mode arising when a segment tilt on M1 is compensated on-axis by a segment tilt on M2. We will show thatwhen using an asterism of SPS, our scheme can properly control both segment piston and the FDSP mode.

NFIRAOS, the first light AO system for the Thirty Meter Telescope, will include a natural guide star (NGS) pyramidwave-front sensor (PWFS). This WFS will have two functions: (i) when there is a bright enough NGS within the sciencefield and the lasers are turned off, the PWFS will act as the fast high order WFS driving the SCAO loop (e.g. for highcontrastimaging); and (ii) when the lasers are in use and the system operates in MCAO mode, the PWFS will act as aslow truth WFS (e.g. to measure drifts in the structure of the sodium layer). The decision to select a PWFS instead of amore conventional Shack-Hartmann WFS (SHWFS) is the outcome of a detailed trade study. In this paper, wesummarize the results of this trade study. These include extensive simulation work, which shows that, in the expectedoperating conditions of NFIRAOS, the PWFS will bring significant performance improvements, including higher Strehlratio, higher limiting magnitude and lower residual speckle levels for high contrast imaging, even when the system hasto correct for significant levels of non-common path aberrations. Our simulation results also provides new insights onthe properties of the PWFSs. We also report on opto-mechanical design work, which shows that, with the PWFS, the twofunctions (i) and (ii) can actually be combined into a single optical path, thus reducing the complexity in terms ofnumber of mechanisms and optical elements. Finally, we discuss the impacts of switching to a PWFS on the otheralready designed NFIRAOS sub-systems (e.g. the real-time computer), which we have found to be very modest.

The Giant Magellan Telescope (GMT) consists of seven 8.365 m segments with a separation of 0.345 m. A uniquechallenge for GMT lies in phasing these segments and, in particular, how to measure segment piston optically.In this paper, we present a results of a phasing strategy using a non-redundant pupil mask. We show how thismethod can be extended to measure segment piston differences of more than half a wave by using broadbandlight.

We report the progress of the Canary High-Order Upgrade (CHOUGH) addition to the CANARY AO experimentat the 4.2m WHT telescope, ORM, La Palma. While CANARY has been developed to investigate severaltomographic congurations relevant to the E-ELT, it also has the ability to host guest AO instruments andprovide them with relevant infrastructure. CHOUGH is a self-contained AO bench that integrates into CANARY,via an external feed of light, to provide a Strehl 0:5 in the visible. Within CANARY, CHOUGH picks o lightafter a 240-actuator deformable mirror and delivers the on-axis beam into the internal relay which feeds varioussub-systems. These are include pick-o optics, a ADC, and 1k-actuator DM, all of which are part of an internalrelay to three instruments: a spatially-ltered SH WFS, a calibration interferometer, and a narrow-eld imagingcamera. As CHOUGH is constructed on a separate breadboard, the components are self-contained and can beintegrated and operated separately from CANARY. In this paper the progress on the design, procurement, andperformance of the CHOUGH sub-systems and the experiment as a whole is given. Attention is given to thealgorithms that will be used and the control methods that will be utilized on-sky. The modular nature of thedesign leads to potential upgrade paths and a brief discussion is made of new directions of on-sky research thatcould be carried out with replacement sub-systems and new instrumentation.

The SPHERE instrument (Beuzit, et al., 2010) is dedicated to the direct imaging of extra-solar planets. This kind of observation allows one to study the photons emitted by the planet’s atmosphere itself, or reflected by its surface. The search for bio-markers is therefore made possible. The SPHERE instrument has been installed and commissioned at VLT Paranal Observatory during 2014 and now routinely delivers high contrast images to the exoplanet community. This paper presents a study of the main actual limitation of the SPHERE instrument, as known as the Low Wind Effect [LWE]. This effect has been discovered on SPHERE during commissioning period. Its effect is a strong degradation of the instrument PSF, preventing instrument to perform high contrast imaging. It happens during particularly low wind conditions (below 1m/s at the telescope level) which happens one night out of five.

ARGOS is the laser guide star facility of the Large Binocular Telescope (LBT). It implements a Rayleigh Laser Guide Star system that provides Ground Layer Adaptive Optics (GLAO) correction for the LUCIs, the 2 wide- field near-infrared imagers and multi-object spectrographs installed on the 2 eyes of LBT. In this paper we describe how LBT’s adaptive optics operations have been tailored to ARGOS’s use cases based on the experience developed during over the ARGOS commissioning. We focus on all the aspects that are influenced by the use of the Laser Guide Stars, from collimation to acquisition and LGS guiding and we details the sequences to start, pause and resume the adaptive correction.

In this paper, we present a tomographic reconstruction method to reduce a tomographic error, multi time-stepreconstruction, for a wide-eld adaptive optics (WFAO). Based on the frozen ow assumption, we can computethe time evolution of measurements from wave-front sensors (WFS) at previous time-steps with using windinformation. Our idea is to reduce the tomographic error by using the measurements at both the current andprevious time-steps simultaneously. We also develop a method to estimate wind speed and direction at eachaltitude from temporal correlations of phase distortion pattern reconstructed by a classical tomography. Weevaluate the performance of the method by a laboratory experiment with the RAVEN, a multi-object adaptiveoptics (MOAO) technical and science demonstrator. In the laboratory experiment, our wind estimation methodcan estimate wind speeds and directions of multiple layers. By the multi time-step reconstruction method, theensquared energy in a 140 mas box increases about 3{5% compared with a classical tomographic reconstruction.

We propose a new type of Wave Front Sensor (WFS) derived from the Pyramid WFS (PWFS). 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. This map is then used to derive the phase information. 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. 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. Furthermore, the pixel arrangement being more efficient than for the PWFS,the FPWFS seems particularly well suited for high-contrast applications. 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. Finally, we also show that replacing the pyramid with aflattened cone also leads to very promising noise propagation properties.

The M4DP is the demonstration prototype of the E-ELT adaptive mirror M4. The opticalcalibration and test of the M4DP, held in INAF laboratories during February and March 2015, has beena lesson learned for the forthcoming optical verification of the 5000 actuators, 6 segments final unit.The test procedure was tailored to fit the peculiarities of such 2 segments, 222 actuators prototype. Keyelements are the simultaneous segments control and the measurement and correction of the rigid modesover the segmented pupil; convection noise aecting the phasing was also investigated. In this paper wewill report the results of the optical test and the specific solutions implemented for the phasing controland performance verification.

Raven is a Multi-Object Adaptive Optics science demonstrator which has been used on-sky at Subaru telescope from May 2014 to July 2015. Raven has been developed at the University of Victoria AO Lab, in partnership with NRC, NAOJ and Tohoku University. Raven includes three open loop WFSs, a central laser guide star WFS, and two science pick-off arms feeding light to the Subaru IRCS spectrograph. Raven supports different AO modes: SCAO, open-loop GLAO and MOAO. This paper gives an overview of the instrument design, compares the on-sky performance of the different AO modes and presents some of the science results achieved with MOAO.

The TMT first light Adaptive Optics (AO) facility consists of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). NFIRAOS is a 60 x 60 laser guide star (LGS) multi-conjugate AO (MCAO) system, which provides uniform, diffraction-limited performance in the J, H, and K bands over 17-30 arc sec diameter fields with 50 per cent sky coverage at the galactic pole, as required to support the TMT science cases. NFIRAOS includes two deformable mirrors, six laser guide star wavefront sensors, and several low-order, infrared, natural guide star wavefront sensors within each client instrument. The first light LGSF system includes six sodium lasers required to generate the NFIRAOS laser guide stars. In this paper, we will provide an update on the progress in designing, modeling and validating the TMT first light AO systems and their components over the last two years. This will include the final design activities for NFIRAOS, preliminary design activities for the LGSF, final design and prototyping activities for the deformable mirrors, final design and fabrication for the visible detectors, preliminary design activities for the NFIRAOS visible cameras, preliminary design activities for the NFIRAOS Real Time Controller (RTC) and development and tests of prototype candidate lasers. Comprehensive and detailed AO modeling is also continuing to support the design and development of the first light AO facility.

We present the final development of our point spread function reconstruction algorithm for the Keck-II telescope adaptive optics system, in laser and natural guide star modes. The method makes use of AO loop teleme- try, nearby CN2 profiler data, and on-sky phase diversity. We describe the fundamental assumptions and the mathematical models for each components of the residual phase structure function. The reconstructed PSF is compared with on-sky single star PSF. We emphasize the importance of access to a good telemetry and the fact that non-common path aberrations also affects PSF-R. The global, statistical quality of the reconstructed PSF demonstrates the validity of the method. The algorithm is now ready for AO science data reduction (see the companion overview paper, Ragland et al.1 - this conference).

The use of deformable mirrors for the compensation of the effect of the atmospheric turbulence in Adaptive Optics (AO) systems requires a very fast computation of the adequate commands with the information provided by wavefront sensors. Providing accurate results with minimum latency is vital to achieve optimum performance. Conventional CPUs, GPUs and also FPGAs have been successfully used in real-time control for AO at IAC for a number of projects (EDIFISE, AOLI, AOconFPGA, GTCAO). Based in this experience, a comparative description is made in this paper, pointing out advantages and drawbacks of each solution as seen by each of the projects.

The Giant Magellan Telescope (GMT) is a gregorian 25.5-meter diameter primary mirror (M1) made of 7 8.4-meter diameter circular aspheric segments. The secondary mirror (M2) is a 1/8th down-scale model of M1 madeof 7 1- meter diameter segments. Each segments has positionners to adjust its 6 rigid body motions. The gureof M1 segment is controlled with 44 bending modes and M2 segments are deformed using 672 actuators. Inthe active and adaptive operation modes of the GMT, around a dozen wavefront sensors (WFS) are selectivelyused to monitor the optical aberrations building-up into the telescope. A dedicated control system feeds backthe WFS measurements to the mirrors actuators to deliver image quality optimized for the eld of view of eachscientic instrument. This paper describes the GMT Dynamic Optical Simulation (DOS) tool. DOS integratesthe optical and mechanical model of the telescope together with the control system. DOS is a cloud-basedoptical propagation software package with build-in models for both geometric and Fourier optics and a fullcontrol algorithm development environment.

The MAORY adaptive optics module is part of the first light instrumentation suite for the E-ELT. The MAORY project phase B is going to start soon. This paper contains a system-level overview of the current instrument design.

A new coronagraphic instrument for the Large Binocular Telescope (LBT) has successfully passed the conceptual design phase. SHARK-NIR channel will be installed in one arm of the Large Binocular Telescope and it is designed to use different coronagraphic techniques, both to match as much as possible the different requirements of the different science cases and to explore the capabilities of such techniques for the next-generation of ELTs. By exploiting the combination with SHARK-VIS channel mounted at the other LBT arm, the instrument will offer simultaneous coronagraphic observations at different wavelengths, characterized by high contrast, even for relatively faint targets. This will be achievable thanks to the very efficient Adaptive Optics (AO) systems already operating at LBT (First Light AO, FLAO). Furthermore, the latter will be soon upgraded with new detectors, promising even better performance in terms of limiting magnitude. In this paper we present the status of the SHARK-NIR channel design.

Direct detection and characterization of exoplanets is a major scientific driver of the next decade. Direct imaging requires challenging techniques to observe faint companions around bright stars. The development of future large telescopes will increase the capability to directly image and characterize exoplanets thanks to their high resolution and photon collecting power. The E-ELT will be composed of a segmented ~40 m-diameter primary mirror. High contrast imaging techniques for E-ELT will thus need to deal with amplitude errors due to segmentation (pupil discontinuities between the segments). A promising technique is the wavefront shaping. It consists in the use of deformable(s) mirror(s) to cancel the intensity inside the focal plane region. Algorithm improvements and laboratory demonstrations have been developed since the last 20 years. The use of 2 deformable mirrors (DM) in non-conjugated planes will allow correcting not only for phase aberrations but also for the amplitude errors. Lagrange laboratory has begun in 2013 the development of an instrumental project called SPEED (Segmented Pupil Experiment for Exo-planet Detection). Its goal is to develop and test high-contrast imaging techniques optimized for segmented pupil. In this paper we present a detailed end-to-end simulation for the optimization of the SPEED experiment optical design. In particular, we pay attention to the optimal separation between the two DMs necessary for phase and amplitude correction. The trade-off between various parameters (field of correction, field of view, size constraints,...) is presented and discussed.

We present the final development of our point spread function reconstruction algorithm for the Keck-II telescope adaptive optics system, in laser and natural guide star modes. The method makes use of AO loop teleme- try, nearby CN2 profiler data, and on-sky phase diversity. We describe the fundamental assumptions and the mathematical models for each components of the residual phase structure function. The reconstructed PSF is compared with on-sky single star PSF. We emphasize the importance of access to a good telemetry and the fact that non-common path aberrations also affects PSF-R. The global, statistical quality of the reconstructed PSF demonstrates the validity of the method. The algorithm is now ready for AO science data reduction (see the companion overview paper, Ragland et al.1 - this conference).

In this paper, we discuss the feasibility and the performance assessment of a possible MCAO system for E-ELT, basedon the novel concept of Global MCAO, which takes advantage of a very wide technical FoV to perform adaptive opticscorrection using only natural guide stars, with the aim to increase the sky coverage. The technique envisages thedefinition of Virtual-DMs, as tools for the global reconstruction. This investigation has been carried out during afeasibility study we performed for ESO, in which we combined computations, simulations and literature. The aim of thisanalysis is to identify and review the main parameters and the technical issues, which would act as error sources in a realGMCAO system, evaluating their contribution to the overall performance. The study involves both issues related to thePyramid WFS in general, and to the GMCAO case in particular, including the wavelength and FoV size selection, thenumber of guide stars and reconstructed Virtual-DMs, and actual components parameters.

Every observatory using LGS-AO routinely has the experience of the long time needed to bring and acquire the laser guide star in the wavefront sensor field of view. This is mostly due to the difficulty of creating LGS pointing models, because of the opto-mechanical flexures and hysteresis in the launch and receiver telescope structures.The launch telescopes are normally sitting on the mechanical structure of the larger receiver telescope. The LGS acquisition time is even longer in case of multiple LGS systems. In this framework the optimization of the LGS systems absolute pointing accuracy is relevant to boost the time efficiency of both science and technical observations.In this paper we describe the design and functionalities of the Laser Pointing Camera (LPC)3, developed at OAR for the 4LGSF of the ESO Adaptive Optics Facility. The LPC allows to have a fast pointing of the multiple LGS on the AO WFS during the initial acquisition phase of the telescope preset, thus reducing considerably the overheads currently experienced in most LGS-AO systems in operation.By recognizing via astrometric software the field stars as well as the multiple LGS, LPC is insensitive to flexures of the laser launch telescope or of the receiver telescope opto-mechanics. Moreover, LPC gives regularly the photometry and fwhm of the LGS, as well as the scattering of the uplink beams at the height of 10-15km, thus monitoring the presence and evolution of cirrus clouds. We present the first Commissioning results of the Laser Pointing Camera, obtained at the ESO VLT during the 4LGSF first Laser Guide Star Unit Commissioning, and will discuss its possible extension for the ELT operations.

In this paper, we will present new compression algorithms to determine optimal layer heights and turbulenceweights for the tomographic reconstruction in wide field AO systems. Among other approaches, a new compressionmethod based on discrete optimization of collecting atmospheric layers to subgroups is discussed. Furthermore,studies of the influence of layer heights and c2n-profiles on the reconstruction quality for differentreconstruction algorithms and atmospheric profiles will be shown. Our comparison suggests that reconstructionson fewer atmospheric layers yield comparable quality with lower computational effort, if an appropriatecompression algorithm is used. The numerical results were obtained on the ESO end-to-end simulation toolOCTOPUS.

The time evolution of the sodium profile greatly impact the accuracy of laser guide star (LGS) wavefront sensor (WFS) measurements, for either the traditional thresholded center of gravity or the more advanced constraint matched filter/correlation algorithms. As a result, circularly symmetric wavefront aberrations will be induced in the adaptive optics (AO) corrected science wavefront for center launch LGS. In this paper, we describe our scheme to mitigate this issue by updating pixel processing parameters and employing a truth WFS during LGS AO operation. We also present simulation results using the sodium profiles measured by the UBC lidar. In addition, the time evolution of the turbulence profile will also have an impact on the pixel processing accuracy for the advanced algorithms, as well as the minimum variance wavefront reconstruction. We present simulation results showing how often we have to update the corresponding parameters to minimize the effect.

LINC-NIRVANA (LN) is an instrument built to be a Fizeau interferometric imager for the Large Binocular Telescope that will achieve ELT-like spatial resolution. Of course achieving this outstanding resolution requires a very complex instrument, assuring the delivery of plane wavefronts, parallel input beams, homoteticity and zero Optical Path Difference. LN will be one of the most complex ground-based instruments ever built, consisting of a Multi-Conjugate Adaptive Optics (MCAO) system, a fringe tracker, a beam combiner and a Near-InfraRed science camera, for a total of more than 250 indivudual lenses and mirrors.The MCAO sub-unit itself is the state of the art in the sector of wide field adaptive optics. It consists of 4 Wavefront Sensors (WFSs), two for each arm of the telescope, to sense the turbulence at the ground layer and at 7.1 km above the telescope. They operate in a layer oriented, Multiple Field of View mode, using up to 12 Natural Guide Stars (NGSs) for the ground layer correction and up to 8 NGSs for the mid layer correction.The ambitious nature of LN, which compels us to meet very tight requirements, together with the high number of subsystems lead to a challenging alignment procedure of the instrument. Despite of the complexity, the Alignment, Integration and Verification phase of the instrument has been recently completed with success in Heidelberg and LN is currently on its way to the LBT, where it will be re-aligned and finally mounted at one of the bend focal stations of the telescope. In this paper the integration and alignment procedure of the MCAO subsystem to the rest of LN is described and results are presented.

To date, the OCAM2 system has demonstrated to be the fastest and lowest noise production ready wavefront sensor, achieving 2067 full frames per second with subelectron readout noise. This makes OCAM2 the ideal system for natural as well as continuous wave laser guide star wavefront sensing. In this paper we present the new gated version of OCAM2 named OCAM2-S, using E2V’s CCD219 sensor with integral shutter. This new camera offers the same superb characteristics than OCAM2 both in terms of speed and readout noise but also offers a shutter function that makes the sensor only sensitive to light for very short periods, at will. We will report on gating time and extinction ratio performances of this new camera. This device opens new possibilities for Rayleigh pulsed lasers adaptive optics systems. With a shutter time constant well below 1 microsecond, this camera opens new solutions for pulsed sodium lasers with backscatter suppression or even spot elongation minimization for ELT LGS. This camera has been successfully used for the first time on the CANARY instrument on the William Herschel Telescope. The final phase of CANARY is a demonstrator of a single MOAO channel for the proposed EAGLE instrument on the future European ELT. We will report on-sky performance with this instrument.

We present the final development of our point spread function reconstruction algorithm for the Keck-II telescope adaptive optics system, in laser and natural guide star modes. The method makes use of AO loop teleme- try, nearby CN2 profiler data, and on-sky phase diversity. We describe the fundamental assumptions and the mathematical models for each components of the residual phase structure function. The reconstructed PSF is compared with on-sky single star PSF. We emphasize the importance of access to a good telemetry and the fact that non-common path aberrations also affects PSF-R. The global, statistical quality of the reconstructed PSF demonstrates the validity of the method. The algorithm is now ready for AO science data reduction (see the companion overview paper, Ragland et al.1 - this conference).

Raven is a Multi-Object Adaptive Optics science demonstrator which has been used on-sky at Subaru telescope from May 2014 to July 2015. Raven has been developed at the University of Victoria AO Lab, in partnership with NRC, NAOJ and Tohoku University. Raven includes three open loop WFSs, a central laser guide star WFS, and two science pick-off arms feeding light to the Subaru IRCS spectrograph. Raven supports different AO modes: SCAO, open-loop GLAO and MOAO. This paper gives an overview of the instrument design, compares the on-sky performance of the different AO modes and presents some of the science results achieved with MOAO.

The M4DP is the demonstration prototype of the E-ELT adaptive mirror M4. The opticalcalibration and test of the M4DP, held in INAF laboratories during February and March 2015, has beena lesson learned for the forthcoming optical verification of the 5000 actuators, 6 segments final unit.The test procedure was tailored to fit the peculiarities of such 2 segments, 222 actuators prototype. Keyelements are the simultaneous segments control and the measurement and correction of the rigid modesover the segmented pupil; convection noise aecting the phasing was also investigated. In this paper wewill report the results of the optical test and the specific solutions implemented for the phasing controland performance verification.

We propose a new type of Wave Front Sensor (WFS) derived from the Pyramid WFS (PWFS). 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. This map is then used to derive the phase information. 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. 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. Furthermore, the pixel arrangement being more efficient than for the PWFS,the FPWFS seems particularly well suited for high-contrast applications. 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. Finally, we also show that replacing the pyramid with aflattened cone also leads to very promising noise propagation properties.

Every observatory using LGS-AO routinely has the experience of the long time needed to bring and acquire the laser guide star in the wavefront sensor field of view. This is mostly due to the difficulty of creating LGS pointing models, because of the opto-mechanical flexures and hysteresis in the launch and receiver telescope structures.The launch telescopes are normally sitting on the mechanical structure of the larger receiver telescope. The LGS acquisition time is even longer in case of multiple LGS systems. In this framework the optimization of the LGS systems absolute pointing accuracy is relevant to boost the time efficiency of both science and technical observations.In this paper we describe the design and functionalities of the Laser Pointing Camera (LPC)3, developed at OAR for the 4LGSF of the ESO Adaptive Optics Facility. The LPC allows to have a fast pointing of the multiple LGS on the AO WFS during the initial acquisition phase of the telescope preset, thus reducing considerably the overheads currently experienced in most LGS-AO systems in operation.By recognizing via astrometric software the field stars as well as the multiple LGS, LPC is insensitive to flexures of the laser launch telescope or of the receiver telescope opto-mechanics. Moreover, LPC gives regularly the photometry and fwhm of the LGS, as well as the scattering of the uplink beams at the height of 10-15km, thus monitoring the presence and evolution of cirrus clouds. We present the first Commissioning results of the Laser Pointing Camera, obtained at the ESO VLT during the 4LGSF first Laser Guide Star Unit Commissioning, and will discuss its possible extension for the ELT operations.

The MAORY adaptive optics module is part of the first light instrumentation suite for the E-ELT. The MAORY project phase B is going to start soon. This paper contains a system-level overview of the current instrument design.

NFIRAOS, the first light AO system for the Thirty Meter Telescope, will include a natural guide star (NGS) pyramidwave-front sensor (PWFS). This WFS will have two functions: (i) when there is a bright enough NGS within the sciencefield and the lasers are turned off, the PWFS will act as the fast high order WFS driving the SCAO loop (e.g. for highcontrastimaging); and (ii) when the lasers are in use and the system operates in MCAO mode, the PWFS will act as aslow truth WFS (e.g. to measure drifts in the structure of the sodium layer). The decision to select a PWFS instead of amore conventional Shack-Hartmann WFS (SHWFS) is the outcome of a detailed trade study. In this paper, wesummarize the results of this trade study. These include extensive simulation work, which shows that, in the expectedoperating conditions of NFIRAOS, the PWFS will bring significant performance improvements, including higher Strehlratio, higher limiting magnitude and lower residual speckle levels for high contrast imaging, even when the system hasto correct for significant levels of non-common path aberrations. Our simulation results also provides new insights onthe properties of the PWFSs. We also report on opto-mechanical design work, which shows that, with the PWFS, the twofunctions (i) and (ii) can actually be combined into a single optical path, thus reducing the complexity in terms ofnumber of mechanisms and optical elements. Finally, we discuss the impacts of switching to a PWFS on the otheralready designed NFIRAOS sub-systems (e.g. the real-time computer), which we have found to be very modest.

In this paper, we will present new compression algorithms to determine optimal layer heights and turbulenceweights for the tomographic reconstruction in wide field AO systems. Among other approaches, a new compressionmethod based on discrete optimization of collecting atmospheric layers to subgroups is discussed. Furthermore,studies of the influence of layer heights and c2n-profiles on the reconstruction quality for differentreconstruction algorithms and atmospheric profiles will be shown. Our comparison suggests that reconstructionson fewer atmospheric layers yield comparable quality with lower computational effort, if an appropriatecompression algorithm is used. The numerical results were obtained on the ESO end-to-end simulation toolOCTOPUS.

LINC-NIRVANA (LN) is an instrument built to be a Fizeau interferometric imager for the Large Binocular Telescope that will achieve ELT-like spatial resolution. Of course achieving this outstanding resolution requires a very complex instrument, assuring the delivery of plane wavefronts, parallel input beams, homoteticity and zero Optical Path Difference. LN will be one of the most complex ground-based instruments ever built, consisting of a Multi-Conjugate Adaptive Optics (MCAO) system, a fringe tracker, a beam combiner and a Near-InfraRed science camera, for a total of more than 250 indivudual lenses and mirrors.The MCAO sub-unit itself is the state of the art in the sector of wide field adaptive optics. It consists of 4 Wavefront Sensors (WFSs), two for each arm of the telescope, to sense the turbulence at the ground layer and at 7.1 km above the telescope. They operate in a layer oriented, Multiple Field of View mode, using up to 12 Natural Guide Stars (NGSs) for the ground layer correction and up to 8 NGSs for the mid layer correction.The ambitious nature of LN, which compels us to meet very tight requirements, together with the high number of subsystems lead to a challenging alignment procedure of the instrument. Despite of the complexity, the Alignment, Integration and Verification phase of the instrument has been recently completed with success in Heidelberg and LN is currently on its way to the LBT, where it will be re-aligned and finally mounted at one of the bend focal stations of the telescope. In this paper the integration and alignment procedure of the MCAO subsystem to the rest of LN is described and results are presented.

A new coronagraphic instrument for the Large Binocular Telescope (LBT) has successfully passed the conceptual design phase. SHARK-NIR channel will be installed in one arm of the Large Binocular Telescope and it is designed to use different coronagraphic techniques, both to match as much as possible the different requirements of the different science cases and to explore the capabilities of such techniques for the next-generation of ELTs. By exploiting the combination with SHARK-VIS channel mounted at the other LBT arm, the instrument will offer simultaneous coronagraphic observations at different wavelengths, characterized by high contrast, even for relatively faint targets. This will be achievable thanks to the very efficient Adaptive Optics (AO) systems already operating at LBT (First Light AO, FLAO). Furthermore, the latter will be soon upgraded with new detectors, promising even better performance in terms of limiting magnitude. In this paper we present the status of the SHARK-NIR channel design.

We present in this paper preliminary simulation results aimed at validating the GMT piston control strategy. Wewill in particular consider an observing mode in which an Adaptive Optics (AO) system is providing fast on-axisWF correction with the Adaptive Secondary Mirror (ASM), while the phasing system using multiple SegmentPiston Sensors (SPS) makes sure that the seven GMT segments remain phased. Simulations have been performedwith the Dynamic Optical Simulation (DOS) tool developed at the GMT Project Oce, which integrates theoptical and mechanical models of GMT. DOS fast ray-tracing capabilities allows us to properly simulate theeect of eld-dependent aberrations, and in particular, the so-called Field Dependent Segment Piston (FDSP)mode arising when a segment tilt on M1 is compensated on-axis by a segment tilt on M2. We will show thatwhen using an asterism of SPS, our scheme can properly control both segment piston and the FDSP mode.

Direct detection and characterization of exoplanets is a major scientific driver of the next decade. Direct imaging requires challenging techniques to observe faint companions around bright stars. The development of future large telescopes will increase the capability to directly image and characterize exoplanets thanks to their high resolution and photon collecting power. The E-ELT will be composed of a segmented ~40 m-diameter primary mirror. High contrast imaging techniques for E-ELT will thus need to deal with amplitude errors due to segmentation (pupil discontinuities between the segments). A promising technique is the wavefront shaping. It consists in the use of deformable(s) mirror(s) to cancel the intensity inside the focal plane region. Algorithm improvements and laboratory demonstrations have been developed since the last 20 years. The use of 2 deformable mirrors (DM) in non-conjugated planes will allow correcting not only for phase aberrations but also for the amplitude errors. Lagrange laboratory has begun in 2013 the development of an instrumental project called SPEED (Segmented Pupil Experiment for Exo-planet Detection). Its goal is to develop and test high-contrast imaging techniques optimized for segmented pupil. In this paper we present a detailed end-to-end simulation for the optimization of the SPEED experiment optical design. In particular, we pay attention to the optimal separation between the two DMs necessary for phase and amplitude correction. The trade-off between various parameters (field of correction, field of view, size constraints,...) is presented and discussed.

The use of deformable mirrors for the compensation of the effect of the atmospheric turbulence in Adaptive Optics (AO) systems requires a very fast computation of the adequate commands with the information provided by wavefront sensors. Providing accurate results with minimum latency is vital to achieve optimum performance. Conventional CPUs, GPUs and also FPGAs have been successfully used in real-time control for AO at IAC for a number of projects (EDIFISE, AOLI, AOconFPGA, GTCAO). Based in this experience, a comparative description is made in this paper, pointing out advantages and drawbacks of each solution as seen by each of the projects.

The Giant Magellan Telescope (GMT) consists of seven 8.365 m segments with a separation of 0.345 m. A uniquechallenge for GMT lies in phasing these segments and, in particular, how to measure segment piston optically.In this paper, we present a results of a phasing strategy using a non-redundant pupil mask. We show how thismethod can be extended to measure segment piston differences of more than half a wave by using broadbandlight.

To date, the OCAM2 system has demonstrated to be the fastest and lowest noise production ready wavefront sensor, achieving 2067 full frames per second with subelectron readout noise. This makes OCAM2 the ideal system for natural as well as continuous wave laser guide star wavefront sensing. In this paper we present the new gated version of OCAM2 named OCAM2-S, using E2V’s CCD219 sensor with integral shutter. This new camera offers the same superb characteristics than OCAM2 both in terms of speed and readout noise but also offers a shutter function that makes the sensor only sensitive to light for very short periods, at will. We will report on gating time and extinction ratio performances of this new camera. This device opens new possibilities for Rayleigh pulsed lasers adaptive optics systems. With a shutter time constant well below 1 microsecond, this camera opens new solutions for pulsed sodium lasers with backscatter suppression or even spot elongation minimization for ELT LGS. This camera has been successfully used for the first time on the CANARY instrument on the William Herschel Telescope. The final phase of CANARY is a demonstrator of a single MOAO channel for the proposed EAGLE instrument on the future European ELT. We will report on-sky performance with this instrument.

ARGOS is the laser guide star facility of the Large Binocular Telescope (LBT). It implements a Rayleigh Laser Guide Star system that provides Ground Layer Adaptive Optics (GLAO) correction for the LUCIs, the 2 wide- field near-infrared imagers and multi-object spectrographs installed on the 2 eyes of LBT. In this paper we describe how LBT’s adaptive optics operations have been tailored to ARGOS’s use cases based on the experience developed during over the ARGOS commissioning. We focus on all the aspects that are influenced by the use of the Laser Guide Stars, from collimation to acquisition and LGS guiding and we details the sequences to start, pause and resume the adaptive correction.

We report the progress of the Canary High-Order Upgrade (CHOUGH) addition to the CANARY AO experimentat the 4.2m WHT telescope, ORM, La Palma. While CANARY has been developed to investigate severaltomographic congurations relevant to the E-ELT, it also has the ability to host guest AO instruments andprovide them with relevant infrastructure. CHOUGH is a self-contained AO bench that integrates into CANARY,via an external feed of light, to provide a Strehl 0:5 in the visible. Within CANARY, CHOUGH picks o lightafter a 240-actuator deformable mirror and delivers the on-axis beam into the internal relay which feeds varioussub-systems. These are include pick-o optics, a ADC, and 1k-actuator DM, all of which are part of an internalrelay to three instruments: a spatially-ltered SH WFS, a calibration interferometer, and a narrow-eld imagingcamera. As CHOUGH is constructed on a separate breadboard, the components are self-contained and can beintegrated and operated separately from CANARY. In this paper the progress on the design, procurement, andperformance of the CHOUGH sub-systems and the experiment as a whole is given. Attention is given to thealgorithms that will be used and the control methods that will be utilized on-sky. The modular nature of thedesign leads to potential upgrade paths and a brief discussion is made of new directions of on-sky research thatcould be carried out with replacement sub-systems and new instrumentation.

The TMT first light Adaptive Optics (AO) facility consists of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). NFIRAOS is a 60 x 60 laser guide star (LGS) multi-conjugate AO (MCAO) system, which provides uniform, diffraction-limited performance in the J, H, and K bands over 17-30 arc sec diameter fields with 50 per cent sky coverage at the galactic pole, as required to support the TMT science cases. NFIRAOS includes two deformable mirrors, six laser guide star wavefront sensors, and several low-order, infrared, natural guide star wavefront sensors within each client instrument. The first light LGSF system includes six sodium lasers required to generate the NFIRAOS laser guide stars. In this paper, we will provide an update on the progress in designing, modeling and validating the TMT first light AO systems and their components over the last two years. This will include the final design activities for NFIRAOS, preliminary design activities for the LGSF, final design and prototyping activities for the deformable mirrors, final design and fabrication for the visible detectors, preliminary design activities for the NFIRAOS visible cameras, preliminary design activities for the NFIRAOS Real Time Controller (RTC) and development and tests of prototype candidate lasers. Comprehensive and detailed AO modeling is also continuing to support the design and development of the first light AO facility.