Y. Martín

FastCam: a new lucky imaging instrument for medium-sized telescopes

FastCam is an instrument jointly developed by the Spanish Instituto de Astrofísica de Canarias and the Universidad Politécnica de Cartagena designed to obtain high spatial resolution images in the optical wavelength range from ground-based telescopes. The instrument consists of a very low noise and very fast readout speed EMCCD camera capable of reaching the diffraction limit of medium-sized telescopes from 500 to 850 nm. FastCam incorporates a FPGAs-based device to save and evaluate those images minimally disturbed by atmospheric turbulence in real time. The undisturbed images represent a small fraction of the observations. Therefore, a special software package has been developed to extract, from cubes of tens of thousands of images, those with better quality than a given level. This is done in parallel with the data acquisition at the telescope. After the first tests in the laboratory, FastCam has been successfully tested in three telescopes: the 1.52-meter TCS (Teide Observatory), the 2.5-meter NOT, and the 4.2-meter WHT (Roque de los Muchachos Observatory). The theoretical diffraction limit of each telescope has been reached in the I band (850 nm) -0.15, 0.08 and 0.05 arcsec, respectively-, and similar resolutions have been also obtained in the V and R bands. Future work will include the development of a new instrument for the 10.4-meter GTC telescope on La Palma.

The plenoptic camera as a wavefront sensor for the European Solar Telescope (EST)

The plenoptic wavefront sensor combines measurements at pupil and image planes in order to obtain wavefront information from different points of view simultaneously, being capable to sample the volume above the telescope to extract the tomographic information of the atmospheric turbulence. After describing the working principle, a laboratory setup has been used for the verification of the capability of measuring the pupil plane wavefront. A comparative discussion with respect to other wavefront sensors is also included.

Site-seeing measurements for the European Solar Telescope

Seeing measurements are crucial for the optimum design of (multi-conjugate) adaptive optics systems operating at solar telescopes. For the design study of the 4-meter European Solar Telescope, to be located in the Canary Islands, several instruments have been constructed and operated, at the Observatorio del Roque de los Muchachos (La Palma) and at the Observatorio del Teide (Tenerife), to measure the properties of the ground layer and medium-high altitude turbulence. Several units of short (42.34 cm) and two long (323.06 cm) scintillometer bars are, or are to be, installed at both observatories. In addition to them, two wide-field wavefront sensors will be attached to the optical beams of the Swedish tower, on La Palma, and of the German VTT, on Tenerife, simultaneously used with the normal operation of the telescopes. These wavefront sensors are of Shack-Hartmann type with ~1 arcminute field of view. In this contribution, the instruments setup and their performance are described.

Deformable mirror controller for open-loop adaptive optics

A Deformable Mirror Controller (DMC) has been devised to overcome the open-loop nature of Multi Object Adaptive Optics (MOAO), in particular for AO systems with update rates of 1 ms or less. The system is based on a figure sensor, which uses a monochromatic illumination source and a Shack-Hartmann (SH) wavefront sensor (WFS) to obtain a fine sampling of DMs 3D surface. The sensors beam is optically separated from the science path in order to not interfere with science observations. The DMC incorporates a real-time controller in charge of driving the DM. This controller runs in a dedicated Field-Programmable-Gate-Array (FPGA) based processor to keep up with stringent speed requirements. The DMC is being tested in the laboratory and is part of CANARY, an MOAO on-sky demonstrator to be installed at the William Hershel Telescope.

CLOUD TOP HEIGHT ESTIMATION FROM WRF MODEL: APPLICATION TO THE INFRARED CAMERA ONBOARD EUSO-BALLOON (CNES)

EUSO-BALLOON was launched on August 24, 2014 from Timmins (Canada) with a bispectral Infrared Camera onboard intended to measure the cloud coverage during the flight. Clouds at mid and upper levels of the Troposphere are crucial for a proper reconstruction of the main parameters of the Ultra-High Energy Cosmic Rays (UHECR).Therefore, determining Cloud Top Height (CTH) with high accuracy is crucial to estimate the effect of clouds on these measurements. With this aim, we have developed a method to extract CTH parameter via vertical profiles predicted by the Weather Research Forecast (WRF) model. Moreover, we have evaluated model ability to represent temperature and humidity profiles in different climatic regions of the globe.

Status of the GTC adaptive optics: integration in laboratory

Since the beginning of the development of the Gran Telescopio Canarias (GTC), an Adaptive Optics (AO) system was considered necessary to exploit the full diffraction-limited potential of the telescope. The GTC AO system designed during the last years is based on a single deformable mirror conjugated to the telescope pupil, and a Shack-Hartmann wavefront sensor with 20 x 20 subapertures, using an OCAM2 camera. The GTCAO system will provide a corrected beam with a Strehl Ratio (SR) of 0.65 in K-band with bright natural guide stars. Most of the subsystems have been manufactured and delivered. The upgrade for the operation with a Laser Guide Star (LGS) system has been recently approved. The present status of the GTCAO system, currently in its laboratory integration phase, is summarized in this paper.

FPGA-based real time controller for high order correction in EDIFISE

EDIFISE is a technology demonstrator instrument developed at the Institute of Astrophysics of the Canary Islands (IAC), intended to explore the feasibility of combining Adaptive Optics with attenuated optical fibers in order to obtain high spatial resolution spectra at the surroundings of a star, as an alternative to coronagraphy. A simplified version with only tip tilt correction has been tested at the OGS telescope in Observatorio del Teide (Canary islands, Spain) and a complete version is intended to be tested at the OGS and at the WHT telescope in Observatorio del Roque de los Muchachos, (Canary Islands, Spain). This paper describes the FPGA-based real time control of the High Order unit, responsible of the computation of the actuation values of a 97-actuactor deformable mirror (11x11) with the information provided by a configurable wavefront sensor of up to 16x16 subpupils at 500 Hz (128x128 pixels). The reconfigurable logic hardware will allow both zonal and modal control approaches, will full access to select which mode loops should be closed and with a number of utilities for influence matrix and open loop response measurements. The system has been designed in a modular way to allow for easy upgrade to faster frame rates (1500 Hz) and bigger wavefront sensors (240x240 pixels), accepting also several interfaces from the WFS and towards the mirror driver. The FPGA-based (Field Programmable Gate Array) real time controller provides bias and flat-fielding corrections, subpupil slopes to modal matrix computation for up to 97 modes, independent servo loop controllers for each mode with user control for independent loop opening or closing, mode to actuator matrix computation and non-common path aberration correction capability. It also provides full housekeeping control via UPD/IP for matrix reloading and full system data logging.

Design and characterization of the optics and microbolometer electronics breadboard of the infrared camera for JEM-EUSO

JEM-EUSO (Extreme Universe Space Observatory on the Japanese Experiment Module)[1][2] is an advanced observatory that will be on-board the International Space Station (ISS) to observe the UV photon tracks produced by Ultra High Energy Cosmic Rays (UHECR) with energy above 1019 eV. JEM-EUSO will detect the electromagnetic and hadronic components of the Extensive Air Showers (EAS) generated as the result of the UHECR colliding with atmospheric nuclei. Atmospheric monitoring to obtain data, us cloud coverage and cloud top altitude, is crucial for energy estimation of an extreme energy particle. Accordingly JEM-EUSO will include and Atmospheric Monitoring System (AMS)[3] to observe the Earth atmosphere continuously in the FOV of the main telescope. The AMS will comprise an InfraRed CAMera (IRCAM), a LIDAR and JEM-EUSO slow data.

Sol-Gel Glass Coating Synthesis for Different Applications: Active Gradient-Index Materials, Microlens Arrays and Biocompatible Channels

The intent of this chapter is to review the use of sol-gel processing of silica and silica-titania optical coatings in recent research by the authors in three different areas: the synthesis of active gradient-index (GRIN) materials by multilayer deposition of erbiumand ytterbiumdoped silica-titania films, the improvement of the optical and morphological qualities of microlens arrays fabricated by laser ablation and the functionalization of polydimethylsiloxane (PDMS) channel preclinical devices. Through the use of sol-gel, layers with specific properties can be produced. In this regard, undoped and erbiumand ytterbium-doped SiO 2 -TiO 2 films have been produced and characterized using atomic force microscopy (surface topography evaluation) and spectral ellipsometry (determination of optical constants, thickness and porosity of the films). In a second application, a silica sol has been synthesized to coat microlens arrays fabricated by laser ablation. The deposited layer reduces the surface roughness of the microlens array, which yields the improvement of the contrast and the homogeneity of the foci. Finally, PDMS channels fabricated with laser technologies and soft-lithography methods are coated with a sol-gel-derived silica film to avoid the degradation of the material with organic solvents, and their biocompatibility is studied.

Cloud Optical Depth obtained from the Infrared Camera data and the UV Flashers mounted on a helicopter flying under the EUSO

Spain. 2 ISDC, Astronomy Dept. University of Geneva, Switzerland. 3 University of Alabama in Huntsville (UAH), Huntsville, USA. 4 Colorado School of Mines, Golden, USA. 5 GFA. IMA. University of León, León, Spain. 6 Instituto de Astrofísica de Canarias (IAC), Vía Lactea S/N, Tenerife, Spain. 7 IDR/UPM, E. T. S. I. Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Spain. 8 IFIC, CSIC, U. de València. Dpto. Física Atómica, Molecular y Nuclear, U. de València, Spain.