Optical turbulence forecast in the Adaptive Optics realm

(35-words maximum) In this talk I present the scientific drivers related to the optical turbulence forecast applied to the ground-based astronomy supported by Adaptive Optics, the state of the art of the achieved results and the most relevant challenges for future progresses.Comment: 1 figure, Orlando, Florida United States, 25 - 28 June 2018, ISBN: 978-1-943580-44-6,Turbulence & Propagation, JW5I.1 Adaptive Optics: Analysis, Methods and System

Emergence of a collective crystal in a classical system with long-range interactions

A one-dimensional long-range model of classical rotators with an extended degree of complexity, as compared to paradigmatic long-range systems, is introduced and studied. Working at constant density, in the thermodynamic limit one can prove the statistical equivalence with the Hamiltonian Mean Field model (HMF) and $\alpha$-HMF: a second order phase transition is indeed observed at the critical energy threshold $\varepsilon_c=0.75$. Conversely, when the thermodynamic limit is performed at infinite density (while keeping the length of the hosting interval $L$ constant), the critical energy $\varepsilon_c$ is modulated as a function of $L$. At low energy, a self-organized collective crystal phase is reported to emerge, which converges to a perfect crystal in the limit $\epsilon \rightarrow 0$. To analyze the phenomenon, the equilibrium one particle density function is analytically computed by maximizing the entropy. The transition and the associated critical energy between the gaseous and the crystal phase is computed. Molecular dynamics show that the crystal phase is apparently split into two distinct regimes, depending on the the energy per particle $\varepsilon$. For small $\varepsilon$, particles are exactly located on the lattice sites; above an energy threshold $\varepsilon{*}$, particles can travel from one site to another. However, $\varepsilon{*}$ does not signal a phase transition but reflects the finite time of observation: the perfect crystal observed for $\varepsilon >0$ corresponds to a long lasting dynamical transient, whose life time increases when the $\varepsilon >0$ approaches zero.Comment: 6 pages, 4 figure

Forecasting water vapour above the sites of ESO's Very Large Telescope (VLT) and the Large Binocular Telescope (LBT)

Water vapour in the atmosphere is the main source of the atmospheric opacity in the infrared and sub-millimetric regimes and its value plays a critical role in observations done with instruments working at these wavelengths on ground-based telescopes. The scheduling of scientific observational programs with instruments such as the VLT Imager and Spectrometer for mid Infrared (VISIR) at Cerro Paranal and the Large Binocular Telescope Interferometer (LBTI) at Mount Graham would definitely benefit from the ability to forecast the atmospheric water vapour content. In this contribution we present a study aiming at validating the performance of the non-hydrostatic mesoscale Meso-NH model in reliably predicting precipitable water vapour (PWV) above the two sites. For the VLT case we use, as a reference, measurements done with a Low Humidity and Temperature PROfiling radiometer (LHATPRO) that, since a few years, is operating routinely at the VLT. LHATPRO has been extensively validated on previous studies. We obtain excellent performances on forecasts performed with this model, including for the extremely low values of the PWV (<= 1 mm). For the LBTI case we compare one solar year predictions obtained with the Meso-NH model with satellite estimates again obtaining an excellent agreement. This study represents a further step in validating outputs of atmospheric parameters forecasts from the ALTA Center, an operational and automatic forecast system conceived to support observations at LBT and LBTI.Comment: 15 pages, 8 figures, 11 tables, MNRAS accepted on 28 November 201

ALTA Center: Advanced LBT Turbulence and Atmosphere Center Report 12/2019

ALTA Center is a project funded by the Large Binocular Telescope Observatory conceived to support science operations of LBT and LBTI. The main goal is to set-up a completely automatic system to forecast the most important atmospheric and astroclimatic parameters (seeing, isoplanatic angle, wavefront coherence time) relevant for the ground-based astronomical observations, particularly those supported by Adaptive Optics. The project started on 2015 and it has been conceived as a long term project and it is organised on a sequence of contracts of typically five years. The plan has been defined and agreed with the LBTO Director so to be able to supply the required informations on the atmospheric conditions necessary for the LBTO facilities operations, particularly those supported by the Adaptive Optics and the Interferometry. The project has been warmly solicited by the LBTO Director, Christian Veil- let as a piece of a more extended plan aiming to equip LBTO with a set of tools/instrumentations necessary to provide a complete monitoring and character- isation of the atmosphere of Mt.Graham, site of the LBT. The outputs of ALTA Center are supposed to be injected in the LBT Science Operation system designed to optimise the management of the LBT observations [1]. The first contract of ALTA has been conceived to cover a five years activity in the period 2015-2019. At present time ALTA Center is one of the very few centers existent in the astronomical context at a worldwide scale that is able to predict all the key atmo- spherical and astroclimatic parameters relevant for the ground-based astronomy. It is at our knowledge the first and unique center that is able to provide forecasts at short time scales (i.e. a few hours) with such accuracies (see Section 7). It is important to mention that ALTA Center is in continuous evolution. A few functionalities of ALTA could not yet been validated because of a lack of presence of dedicated monitors in situ that are however supposed to be implemented in the next future (for example a MASS - Multi Aperture Scintillation Sensor). This will be included in a forthcoming contract

SOLARNET Optical Turbulence Forecast Report 2019

The H2020 SOLARNET project includes a study to investigate the possibility to set-up systems for the forecast of the optical turbulence in the day-time regimes at the two sites of Roque de los Muchachos Observatory (ORM, La Palma) and Teide Observatory (TO, Tenerife), with a particular attention to the site that will be selected for the European Solar Telescope (EST) [RF1]. More precisely the study (hereafter referred to as the proposed study) aims to upgrade to day-time conditions the method to forecast the optical turbulence (C N2 profiles and integrated astroclimatic parameters) that was developed by the INAF partner for night-time ground-based astronomy. The technique implies the use of a mesoscale model (Meso-Nh) developed by the Centre National des Recherches Meteorologiques (CNRM) and Laboratoire d’Aerologie (LA) in Toulouse (France), and a dedicated code (Astro-Meso-NH) created by Elena Masciadri of INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), to forecast the optical turbulence [RF2]. The Astro-Meso-Nh code is in continuous evolution since more than a decade. It is now managed by the Optical Turbulence team of INAF-OAA and the applications of this code evolved in the time. The most recent version of the code is described in [RF3]. The application to day-time conditions implies new challenges, because the turbulence in day-time presents different features with respect to those developed in night-time, and it is characterised by different typical values for C N2 and derived astroclimatic parameters. This study can lead to the development and implementation of an operational and automatic system for the optical turbulence forecast for EST and other solar telescopes operated at the ORM and TO sites. INAF-OAA has already developed an equivalent system for the Large Binocular Telescope (ALTA Center project – alta.arcetri.astro.it) that runs nightly providing a complete description of the atmosphere conditions (including the optical turbulence). The system is used for the science operations of LBT and in particular to optimize the use of instrumentation supported by the adaptive optics. Such a tool can be considered as a reference with respect to a potential similar tool to be conceived for the EST. The final and ultimate goal of this activity is to develop and implement an operational and automatic system for the optical turbulence forecast for EST and other solar telescopes operated at the ORM and TO sites. This report deals with the availability of optical turbulence measurements above the ORM and TO sites. We are interested on the information on the vertical stratification and integrated values of the monitored quantities. Measurements are very important for the proposed study, because they are required to calibrate the Astro-Meso-Nh model and to validate it for day-time conditions, i.e. to quantify the performances of the model

TURBULENCE PREDICTION: REPORT ON MODEL GEOMETRY

The H2020 SOLARNET project includes a study to investigate the possibility to set-up systems for the forecast of the optical turbulence (OT) in the day-time regimes at the two sites of Roque de los Muchachos Observatory (ORM, La Palma) and Teide Observatory (TO, Tenerife), with a particular attention to the site that will be selected for the European Solar Telescope (EST). More precisely the study aims to upgrade to day-time conditions the method to forecast the OT (C N2 profiles and integrated astroclimatic parameters) that was developed by the INAF partner for night-time ground-based astronomy. The technique implies the use of a mesoscale model (Meso-Nh) [RF1, RF2, RF3, RF4]. Seeing measurements at the ORM and TO are presented in [RF5, RF6]. This document presents the global atmospheric model configuration. This includes the set-up of the orography and the sequence of initialisation. Besides, we analysed also measurements taken by the Stockholm University (SU) partner at the SST with the WF-WFS method in the past years in perspective of using such measurements as a reference to calibrate and/or validate forecasts. In [RF6] measurements taken with a SHABAR by the Istituto de Astrofisica de Canarias (IAC) partner during past years have been analysed with the same philosophy and goal. The analysis of WF-WFS measurements has to be seen as an integration of the [RF6]. We remind that measurements are relevant in this process as they represent the reference with respect to which we can provide an analysis of the forecasts

An ant-colony based approach for real-time implicit collaborative information seeking

This document is an Accepted Manuscript of the following article: Alessio Malizia, Kai A. Olsen, Tommaso Turchi, and Pierluigi Crescenzi, ‘An ant-colony based approach for real-time implicit collaborative information seeking’, Information Processing & Management, Vol. 53 (3): 608-623, May 2017. Under embargo until 31 July 2018. The final, definitive version of this paper is available online at doi: https://doi.org/10.1016/j.ipm.2016.12.005, published by Elsevier Ltd.We propose an approach based on Swarm Intelligence — more specifically on Ant Colony Optimization (ACO) — to improve search engines’ performance and reduce information overload by exploiting collective users’ behavior. We designed and developed three different algorithms that employ an ACO-inspired strategy to provide implicit collaborative-seeking features in real time to search engines. The three different algorithms — NaïveRank, RandomRank, and SessionRank — leverage on different principles of ACO in order to exploit users’ interactions and provide them with more relevant results. We designed an evaluation experiment employing two widely used standard datasets of query-click logs issued to two major Web search engines. The results demonstrated how each algorithm is suitable to be employed in ranking results of different types of queries depending on users’ intent.Peer reviewedFinal Accepted Versio

Statistical theory of quasi stationary states beyond the single water-bag case study

An analytical solution for the out-of-equilibrium quasi-stationary states of the paradigmatic Hamiltonian Mean Field (HMF) model can be obtained from a maximum entropy principle. The theory has been so far tested with reference to a specific class of initial condition, the so called (single-level) water-bag type. In this paper a step forward is taken by considering an arbitrary number of overlapping water bags. The theory is benchmarked to direct microcanonical simulations performed for the case of a two-levels water-bag. The comparison is shown to return an excellent agreement

TAPAS : A tangible End-User Development tool supporting the repurposing of Pervasive Displays

This document is the Accepted Manuscript version. Under embargo until 8 June 2018. The final, definitive version is available online at doi: https://doi.org/10.1016/j.jvlc.2016.11.002, published by Elsevier Ltd.These days we are witnessing a spread of many new digital systems in public spaces featuring easy to use and engaging interaction modalities, such as multi-touch, gestures, tangible, and voice. This new user-centered paradigm — known as the NUI — aims to provide a more natural and rich experience to end users; this supports its adoption in many ubiquitous domains, as it naturally holds for Pervasive Displays: these systems are composed of variously-sized displays and support many-to-many interactions with the same public screens at the same time. Due to their public and moderated nature, users need an easy way of adapting them to heterogeneous usage contexts in order to support their long-term adoption. In this paper, we propose an End-User Development approach to this problem introducing TAPAS, a system that combines a tangible interaction with a puzzle metaphor, allowing users to create workflows on a Pervasive Display to satisfy their needs; its design and visual syntax stem from a study we carried out with designers, whose findings are also part of this work. We then carried out a preliminary evaluation of our system with second year university students and interaction designers, gathering useful feedback to improve TAPAS and employ it in many other domains.Peer reviewedFinal Accepted Versio