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Monte Carlo (MC) methods have been shown to capture the ultrafast dynamics of carriers and resulting luminescence in photo-excited GaN. These calculations have assumed a homogeneous material under uniform illumination. We investigate the development of surrogate models to represent the carrier dynamics with fewer degrees of freedom, with the ultimate goal of computing the response of structured materials under inhomogeneous illumination profiles. These models are presently based on the extraction of mean and variance information from single data sets, through the use of fits to s piece-wise linear basis. Two models are then developed, one based on the mean and variance directly, and one on a Gaussian process regression model. New carrier populations with similar statistical profiles are then generated from these models to determine the amount of data reduction that can be obtained.

The CARMENES instrument is a pair of high-resolution (R greater than or similar to 80, 000) spectrographs covering the wavelength range from 0.52 to 1.71 mu m, optimized for precise radial velocity measurements. It was installed and commissioned at the 3.5 m telescope of the Calar Alto observatory in Southern Spain in 2015. The first large science program of CARMENES is a survey of similar to 300 M dwarfs, which started on Jan 1, 2016. We present an overview of all subsystems of CARMENES (front end, fiber system, visible-light spectrograph, near-infrared spectrograph, calibration units, etalons, facility control, interlock system, instrument control system, data reduction pipeline, data flow, and archive), and give an overview of the assembly, integration, verification, and commissioning phases of the project. We show initial results and discuss further plans for the scientific use of CARMENES.

A computer software is proposed in order to determine the centroids of the spots in a Hartmann pattern or Hartmanngrams. The software was developed using algorithms for segmentation of images, which are techniques used in digital image processing. Centroid determination for a Shack-Hartmann pattern is the key point to obtain reliable results. We focus in obtaining good centroid determination for Hartmanngrams under conditions of high noise. The proposed algorithms are the essential part of this work, as they are morphological algorithms, which mainly are modifications of the weighted averaging algorithm. They have several advantages, such as, the adjustment to the shape of every spot of the Hartmanngram and that it is an interactive and automatic software. Although the software is more complete and reliable than other techniques and algorithms, since it can analyze complicated pictures of Hartmanngrams and measure the centroids of the spots.

We describe a new generation of spectral extraction and analysis software package (EDRS2) for the Fibre Optics Cassegrain Echelle Spectrograph (FOCES), which will be attached to the 2m Fraunhofer Telescope on the Wendelstein Observatory. The package is developed based on Python language and relies on a variety of third party, open source packages such as Numpy and Scipy. EDRS2 contains generalized image calibration routines including overscan correction, bias subtraction, flat fielding and background correction, and can be supplemented by user customized functions to fit other echelle spectrographs. An optimal extraction method is adopted to obtain the one dimensional spectra, and the output multi order, wavelength calibrated spectra are saved in FITS files with binary table format. We introduce the algorithm and performance of major routines in EDRS2.

The High Resolution Spectrograph (HRS) on the Southern African Large Telescope (SALT) is a dual beam, fiber-fed echelle spectrograph providing high resolution capabilities to the SALT observing community. We describe the available data reduction tools and the procedures put in place for regular monitoring of the data quality from the spectrograph. Data reductions are carried out through the pyhrs package. The data characteristics and instrument stability are reported as part of the SALT Dashboard to help monitor the performance of the instrument.

The Gemini Planet Imager (GPI) has been designed for the direct detection and characterization of exoplanets and circumstellar disks. GPI is equipped with a dual channel polarimetry mode designed to take advantage of the inherently polarized light scattered off circumstellar material to further suppress the residual seeing haloleft uncorrected by the adaptive optics. We explore how recent advances in data reduction techniques reduce systematics and improve the achievable contrast in polarimetry mode. In particular, we consider different flux extraction techniques when constructing datacubes from raw data, division by a polarized at-field and a method for subtracting instrumental polarization. Using observations of unpolarized standard stars we find that GPI's instrumental polarization is consistent with being wavelength independent within our errors. In addition, we provide polarimetry contrast curves that demonstrate typical performance throughout the GPIES campaign.

The Visible Integral Field Replicable Unit Spectrograph (VIRUS), the instrument for the Hobby Eberly Telescope Dark Energy Experiment (HETDEX), consists of 78 replicable units, each with two integral field spectrographs. Each spectrograph has its own 2kx2k CCD detector with 15 micron pixels. Following alignment, the final stage prior to deployment of each unit is characterization of the 156 spectrograph channels and their CCDs. We describe the laboratory calibration system and scripting that automates this process. Both fiber and continuous (non-spatially modulated) input slits are utilized. Photon transfer curves are made to measure the gain and read noise of each CCD. Pixel flats are also made to correct for pixel-to-pixel QE variations. Relative throughput measurements of each unit are made using the same lab fiber bundle for consistency, and fiber profiles are characterized for later use by the CURE data reduction package. Replicable unit instruments provide a cost effective solution for scaling up instruments for large and extremely large class telescopes. Because VIRUS is the first massively replicated instrument, we have the opportunity to examine the end result of variations in the manufacturing processes that go into production. This paper presents the characterization setup for VIRUS units and compares the performance and variability of processed units with specifications for HETDEX.

Astronomical data sets are growing ever larger, and the area of high contrast imaging of exoplanets is no exception. With the advent of fast, low-noise detectors operating at 10 to 1000 Hz, huge numbers of images can be taken during a single hours-long observation. High frame rates offer several advantages, such as improved registration, frame selection, and improved speckle calibration. However, advanced image processing algorithms are computationally challenging to apply. Here we describe a parallelized, cloud-based data reduction system developed for the Magellan Adaptive Optics VisAO camera, which is capable of rapidly exploring tens of thousands of parameter sets affecting the Karhunen-Loeve image processing (KLIP) algorithm to produce high-quality direct images of exoplanets. We demonstrate these capabilities with a visible wavelength high contrast data set of a hydrogen-accreting brown dwarf companion.

The Kepler mission highlighted that precision radial velocity (PRV) follow-up is a real bottleneck in supporting transiting exoplanet surveys. The limited availability of PRV instruments, and the desire to break the “1 m/s” precision barrier, prompted the formation of a NASA-NSF collaboration ‘NN-EXPLORE’ to call for proposals designing a new Extreme Precision Doppler Spectrograph (EPDS). By securing a significant fraction of telescope time on the 3.5m WIYN at Kitt Peak, and aiming for unprecedented long-term precision, the EPDS instrument will provide a unique tool for U.S. astronomers in characterizing exoplanet candidates identified by TESS. One of the two funded instrument concept studies is led by the Massachusetts Institute of Technology, in consortium with Lincoln Laboratories, Harvard-Smithsonian Center for Astrophysics and the Carnegie Observatories. This paper describes the instrument concept WISDOM (WIYN Spectrograph for DOppler Monitoring) prepared by this team. WISDOM is a fiber fed, environmentally controlled, high resolution (R=110k), asymmetric white-pupil echelle spectrograph, covering a wide 380-1300nm wavelength region. Its R4 and R6 echelle gratings provide the main dispersion, symmetrically mounted on either side of a vertically aligned, vacuum-enclosed carbon fiber optical bench. Each grating feeds two cameras and thus the resulting wavelength range per camera is narrow enough that the VPHG cross-dispersers and employed anti-reflection coatings are highly efficient. The instrument operates near room temperature, and so thermal background for the near-infrared arm is mitigated by thermal blocking filters and a short (1.7μm) cutoff HgCdTe detector. To achieve high resolution while maintaining small overall instrument size (100/125mm beam diameter), imposed by the limited available space within the observatory building, we chose to slice the telescope pupil 6 ways before coupling light into fibers. An atmospheric dispersion corrector and fast tip-tilt system assures maximal light gathering within the 1.2″ entrance aperture. The six octagonal fibers corresponding to each slice of the pupil employ ball-lens double scramblers to stabilize the near- and far-fields. Three apiece are coupled into each of two rectangular fibers, to mitigate modal nose and present a rectilinear illumination pattern at the spectrograph's slit plane. Wavelength solutions are derived from ThAr lamps and an extremely wide coverage dual-channel laser frequency comb. Data is reduced on the fly for evaluation by a custom pipeline, while daily archives and extended scope data reduction products are stored on NExScI servers, also managing archives and access privileges for GTO and GO programs. Note: individual papers, submitted along this main paper, describe the details of subsystems such as the optical design (Barnes et al., 9908-247), the fiber link design (Fűresz et al., 9908-281), and the pupil slicer (Egan et al., 9912-183).

GRAVITY acquisition camera implements four optical functions to track multiple beams of Very Large Telescope Interferometer (VLTI): a) pupil tracker: a $2 \times 2$ lenslet images four pupil reference lasers mounted on the spiders of telescope secondary mirror; b) field tracker: images science object; c) pupil imager: reimages telescope pupil; d) aberration tracker: images a Shack-Hartmann. The estimation of beam stabilization parameters from the acquisition camera detector image is carried out, for every 0.7 s, with a dedicated data reduction software. The measured parameters are used in: a) alignment of GRAVITY with the VLTI; b) active pupil and field stabilization; c) defocus correction and engineering purposes. The instrument is now successfully operational on-sky in closed loop. The relevant data reduction and on-sky characterization results are reported., Comment: SPIE, Optical and Infrared Interferometry and Imaging V, Proceedings Volume 9907, 990727, 2016, "See, https://doi.org/10.1117/12.2233315"

We present the current status of the design of the science data reduction pipeline and the corresponding dataflow system for METIS. It will be one of the first three instruments for the E-ELT and work at wavelengths between 3-19 μm (L/M/N/Q1 bands). We will deliver software which is compliant to standards of the European Southern Observatory (ESO), and will employ state of the art techniques to produce science grade data, master calibration frames, quality control parameters and to handle instrument effects. The Instrument currently offers a wealth of observing modes that are listed in this paper. Data reduction for a ground based instrument at these wavelengths is particularly challenging because of the massive influence of thermal radiation from various sources. We will give a comprehensive overview of the data ow system for the imaging modes that the instrument offers and discuss a single recipe versus a multi recipe approach for the different observing modes for imaging.

In the framework of the international Cherenkov Telescope Array (CTA) gamma-ray observatory, a mini-array of nine small-sized, dual-mirror (SST-2M) telescopes developed by the ASTRI Collaboration has been proposed to be installed at the future CTA southern site. In such a location, the capability of each telescope to process its own data before sending them to a central acquisition system provides a key advantage. We implemented the complete analysis chain required by a single telescope on a NVIDIA® Jetson™ TK1 development board, exceeding the nominal required real-time processing speed by more than a factor two, while staying within a very small power budget.

In this study, we present the experimental investigations on interference patterns, such as those already reported in VIMOS-IFU, and up to now no appropriate explanation has been presented. These interference patterns are produced in multimode fibres coated with acrylate or polyimide, which is the preferred coating material for the fibres used in IFUs. Our experiments show that, under specific conditions, cladding modes interact with the coating and produce interference. Our results show that the conditions at which the fibre is held during data acquisition has an impact in the output spectrum. Altering the positioning conditions of the fibre leads to the changes into the interference pattern, therefore, fibres should be carefully manipulated in order to minimise this potential problem and improve the performance of these instruments. Finally we present a simple way of predicting and modelling this interference produced from the visible to the near infrared spectra. This model can be included in the data reduction pipeline in order to remove the interference patterns. These results should be of interest for the optimisation of the data reduction pipelines of instruments using optical fibres. Considering these results will benefit innovations and developments of high performance fibre systems.

Glioma-derived cancer stem cells (GSCs) are tumor-initiating cells and may be refractory to radiation and chemotherapy and thus have important implications for tumor biology and therapeutics. The analysis and interpretation of large proteomic data sets requires the development of new data mining and visualization approaches. Traditional techniques are insufficient to interpret and visualize these resulting experimental data. The emphasis of this paper lies in the application of novel approaches for the visualization, clustering and projection representation to unveil hidden data structures relevant for the accurate interpretation of biological experiments. These qualitative and quantitative methods are applied to the proteomic analysis of data sets derived from the GSCs. The achieved clustering and visualization results provide a more detailed insight into the protein-level fold changes and putative upstream regulators for the GSCs. However the extracted molecular information is insufficient in classifying GSCs and paving the pathway to an improved therapeutics of the heterogeneous glioma.

We present the proposal for the physical instrument model of the SOXS (Son OF X-Shooter) spectroscopic facility mainly devoted to the follow-up observation of transient sources. A dedicated suitable instrument to exploit the science of these transients is lacking, resulting in severe science "dissipation". SOXS will cover the optical/NIR band (0.35-1.75 μm) with a medium resolution (R 4500), down to the limiting magnitude of R 20-20.5 (1 hr at S/N 10) that is perfectly suited to study transients from on-going imaging surveys. Imaging capabilities in the optical are also foreseen to allow for multi-band photometry of the faintest transients with a field of view of at least 2arcmin. We propose to implement a physical modelling approach in order to link the instrument parameters and behaviour to physical quantities, thus providing a description of the instrument that can be connected with measurements. The method has been already successfully applied to the X-shooter instrument. The X-shooter physical model is based on a kernel optical ray-tracing realised by means of matrix optics representation, which can handle a large number of wavelengths. This can be extended to the SOXS design. The foreseen applications of the SOXS physical model are broad, ranging from support to detailed instrument design and development of the data reduction software, wavelength calibration, evaluation of instrument performance as a function of the model parameters, instrument alignment, and support during the commissioning phase and as a tool for quality check during operations.

To evaluate performance on a perfusion defect detection task from 540 image pairs of myocardial perfusion SPECT image data we apply the J-optimal channelized quadratic observer (J-CQO). We compare AUC values of the linear Hotelling observer and J-CQO when the defect location is fixed and when it occurs in one of two locations. As expected, when the location is fixed a single channels maximizes AUC; location variability requires multiple channels to maximize the AUC. The AUC is estimated from both the projection data and reconstructed images. J-CQO is quadratic since it uses the first- and second- order statistics of the image data from both classes. The linear data reduction by the channels is described by an L x M channel matrix and in prior work we introduced an iterative gradient-based method for calculating the channel matrix. The dimensionality reduction from M measurements to L channels yields better estimates of these sample statistics from smaller sample sizes, and since the channelized covariance matrix is L x L instead of M x M , the matrix inverse is easier to compute. The novelty of our approach is the use of Jeffrey’s divergence (J) as the figure of merit (FOM) for optimizing the channel matrix. We previously showed that the J-optimal channels are also the optimum channels for the AUC and the Bhattacharyya distance when the channel outputs are Gaussian distributed with equal means. This work evaluates the use of J as a surrogate FOM (SFOM) for AUC when these statistical conditions are not satisfied.

The PISCES (Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies) is a lenslet array based integral field spectrograph (IFS) designed to advance the technology readiness of the WFIRST (Wide Field Infrared Survey Telescope)-AFTA (Astrophysics Focused Telescope Assets) high contrast Coronagraph Instrument. We present the end to end optical simulator and plans for the data reduction pipeline (DRP). The optical simulator was created with a combination of the IDL (Interactive Data Language)-based PROPER (optical propagation) library and Zemax (a MatLab script), while the data reduction pipeline is a modified version of the Gemini Planet Imager's (GPI) IDL pipeline. The simulations of the propagation of light through the instrument are based on Fourier transform algorithms. The DRP enables transformation of the PISCES IFS data to calibrated spectral data cubes.

Search for Terrestrial Exo-Planet (STEP)[1] was originally proposed in 2013 by the National Space Science Center, Chinese Academy of Sciences, which is currently being under background engineering study phase in China. The STEP mission is a space astrometry telescope working at visible light wavelengths. The STEP aims at the nearby terrestrial planets detection through micro-arcsecond-level astrometry. Determination of the separation between star images on a detector with high precision is very important for astrometric exoplanets detection through the observation of star wobbles due to planets. The requirement of centroiding accuracy for STEP is 1e-5 pixel. A centroiding experiment have been carried out on a metrology testbed in open laboratory. In this paper, we present the preliminary results of determining the separations between star images. Without calibration of pixel positions and intra-pixel response, we have demonstrated that the standard deviation of differential centroiding is below 7.4e-3 pixel by the algorithm of linear corrected photon weighted means(LCPWM)[2,3]. For comparison, the photon weighted means(PWM) and Gauss fitting are also used in the data reduction. These results pave the way for the geometrical calibration and the intra-pixel quantum efficiency(QE) calibration of detector array equipment for micro-pixel accuracy centroiding.

Chromosome 19 is known to be linked to neurodegeneration and many cancers. Glioma-derived cancer stem cells (GSCs) are tumor-initiating cells and may be refractory to radiation and chemotherapy and thus have important implications for tumor biology and therapeutics. The analysis and interpretation of large proteomic data sets requires the development of new data mining and visualization approaches. Traditional techniques are insufficient to interpret and visualize these resulting experimental data. The emphasis of this paper lies in the presentation of novel approaches for the visualization, clustering and projection representation to unveil hidden data structures relevant for the accurate interpretation of biological experiments. These qualitative and quantitative methods are applied to the proteomic analysis of data sets derived from the GSCs. The achieved clustering and visualization results provide a more detailed insight into the expression patterns for chromosome 19 proteins.

Simple methods for reducing the pulsed thermographic responses of delaminations tend to overestimate the size of the delamination, since the heat diffuses in the plane parallel to the surface. The result is a temperature profile over the delamination which is larger than the delamination size. A variational approach is presented for reducing the thermographic data to produce an estimated size for a flaw that is much closer to the true size of the delamination. The method is based on an estimate for the thermal response that is a convolution of a Gaussian kernel with the shape of the flaw. The size is determined from both the temporal and spatial thermal response of the exterior surface above the delamination and constraints on the length of the contour surrounding the delamination. Examples of the application of the technique to simulation and experimental data are presented to investigate the limitations of the technique.

This paper overviews various methods of data acquisition from GEM detectors. Presented are currently working systems in tokamaks. The data acquisition methods are divided into two parts. First part, devoted to analog signal processing , describes different approaches for signals acquisition, i.e. pulse amplifying and shaping, ASIC use, delay lines. Digital data acquisition part describes presently used high speed interfaces and system standards. Described are also different approaches for data handling, i.e. online analysis, data reduction, system topologies.

In optical coating production the generation of particles and defects is always an undesirable side effect and cannot be completely avoided in the handling steps of the optical components. Particles and defects on the substrates and in the functional coatings lead to scattering and absorption, which may cause a lower damage threshold for components of high power laser application. In this study, results of a long term investigation in the quality and the state of the cleanliness of multilayer systems produced by different deposition techniques are presented. Coated samples of different coating processes are investigated with the help of a Fast Total Scatter scanning system. Adapted data reduction algorithms for the determination of the particle sizes derived from the scattering measurements are developed and applied to the measurement results. On this basis, the density distribution of particle contamination on the samples is evaluated for selected coating runs over a long term period. The calculated statistics of the samples are related to the corresponding production conditions of individual coating plants to extract specific effects of the process environment.

Users of the Atacama Large Millimeter/submillimeter Array (ALMA) are provided with calibration and imaging products in addition to raw data. In Cycle 0 and Cycle 1, these products are produced by a team of data reduction experts spread across Chile, East Asia, Europe, and North America. This article discusses the lines of communication between the data reducers and ALMA users that enable this model of distributed data reduction. This article also discusses the calibration and imaging scripts that have been provided to ALMA users in Cycles 0 and 1, and what will be different in future Cycles., 7 pages, Proceedings of SPIE in Montreal (2014)

NEAT is an astrometric mission proposed to ESA with the objectives of detecting Earth-like exoplanets in the habitable zone of nearby solar-type stars. NEAT requires the capability to measure stellar centroids at the precision of 5 x 10 -6 pixel. Current state-of-the-art methods for centroid estimation have reached a precision of about 2 x 10 -5 pixel at two times Nyquist sampling, this was shown at the JPL by the VESTA experiment. A metrology system was used to calibrate intra and inter pixel quantum efficiency variations in order to correct pixelation errors. The European part of the NEAT consortium is building a testbed in vacuum in order to achieve 5 x 10 -6 pixel precision for the centroid estimation. The goal is to provide a proof of concept for the precision requirement of the NEAT spacecraft. The testbed consists of two main sub-systems. The first one produces pseudo stars: a blackbody source is fed into a large core fiber and lights-up a pinhole mask in the object plane, which is imaged by a mirror on the CCD. The second sub-system is the metrology, it projects young fringes on the CCD. The fringes are created by two single mode fibers facing the CCD and fixed on the mirror. In this paper we present the experiments conducted and the results obtained since July 2013 when we had the first light on both the metrology and pseudo stars. We explain the data reduction procedures we used.

We propose a method to overcome the usual limitation of data reduction pipelines and of the Optical Interferometry FITS format: the absence of correlated and non Gaussian errors. To do so, we use a bootstrap method that allows to sample the probability density function of the interferometric observables. We have applied the method to the accurate assessment of uncertainties on the stellar diameters of under-resolved stars.

The acquisition camera for the GRAVITY/VLTI instrument implements four functions: a) field imager: science field imaging, tip-tilt; b) pupil tracker: telescope pupil lateral and longitudinal positions; c) pupil imager: telescope pupil imaging and d) aberration sensor: The VLTI beam higher order aberrations measurement. We present the dedicated algorithms that simulate the GRAVITY acquisition camera detector measurements considering the realistic imaging conditions, complemented by the pipeline used to extract the data. The data reduction procedure was tested with real aberrations at the VLTI lab and reconstructed back accurately. The acquisition camera software undertakes the measurements simultaneously for all four AT/UTs in 1 s. The measured parameters are updated in the instrument online database. The data reduction software uses the ESO Common Library for Image Processing (CLIP), integrated in to the ESO VLT software environment.

International audience; The present and next few years will see the arrival of several new coronagraphic instruments dedicated to the detection and characterization of planetary systems. These ground- and space-based instruments (Gemini/GPI, VLT/SPHERE, Subaru/ CHARIS, JWST NIRCam and MIRI coronagraphs among others), will provide a large number of new candidates, through multiple nearby-star surveys and will complete and extend those acquired with current generation instruments (Palomar P1640, VLT/NACO, Keck, HST). To optimize the use of the wealth of data, including non-detection results, the science products of these instruments will require to be shared among the community. In the long term such data exchange will significantly ease companion confirmations, planet characterization via different type of instruments (integral field spectrographs, polarimetric imagers, etc.), and Monte-Carlo population studies from detection and non-detection results. In this context, we initiated a collaborative effort between the teams developing the data reduction pipelines for SPHERE, GPI, and the JWST coronagraphs, and the ALICE (Archival Legacy Investigations of Circumstellar Environment) collaboration, which is currently reprocessing all the HST/NICMOS coronagraphic surveys. We are developing a standard format for the science products generated by high-contrast direct imaging instruments (reduced image, sensitivity limits, noise image, candidate list, etc.), that is directly usable for astrophysical investigations. In this paper, we present first results of this work and propose a preliminary format adopted for the science product. We call for discussions in the high-contrast direct imaging community to develop this effort, reach a consensus and finalize this standard. This action will be critical to enable data interchange and combination in a consistent way between several instruments and to stiffen the scientific production in the community.

International audience; We focus on the main algorithms of the data reduction software for the second generation VLTI instrument GRAVITY. From the interferometric data and the metrology signal, the pipeline recovers the complex visibility of the science target with an absolute phase with respect to the fringe tracker target. Visibilities are then calibrated and the relative astrometry is eventually computed when possible.

MATISSE is the mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This second generation interferometry instrument will open new avenues in the exploration of our Universe. Mid-infrared interferometry with MATISSE will allow significant advances in various fundamental research fields: studies of disks around young stellar objects where planets form and evolve, surface structures and mass loss of stars in late evolutionary stages, and the environments of black holes in active galactic nuclei. MATISSE is a unique instrument. As a first breakthrough it will enlarge the spectral domain used by optical interferometry by offering the L & M bands in addition to the N band, opening a wide wavelength domain, ranging from 2.8 to 13 μm on angular scales of 3 mas (L/M band) / 10 mas (N band). As a second breakthrough, it will allow mid-infrared imaging – closure-phase aperture-synthesis imaging – with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. MATISSE will offer various ranges of spectral resolution between R~30 to ~5000. In this article, we present some of the main science objectives that have driven the instrument design. We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performance and discuss the project status. The operations concept will be detailed in a more specific future article, illustrating the observing templates operating the instrument, the data reduction and analysis, and the image reconstruction software.

The Thirty Meter Telescope (TMT) with its first-light multi-conjugate adaptive optics system, NFIRAOS, and high-resolution imager, IRIS, is expected to take differential astrometric measurements with an accuracy on the order of tens of micro arcsec. This requires the control, correction, characterization and calibration of a large number of error sources and uncertainties, many of which have magnitudes much in excess of this level of accuracy. In addition to designing the observatory such that very high precision and accuracy astrometric observations are enabled, satisfying the TMT requirements can only be achieved by a careful calibration, observation and data reduction strategy. In this paper, we present descriptions of the individual errors sources, how and when they apply to different astrometry science cases and the mitigation methods required for each of them, as well as example results for individual error terms and the overall error budgets for a variety of different science cases., Adaptive Optics Systems IV, June 22-27, 2014, Series: Proceedings of SPIE; no. 9148

We present developments in simulations and software for the Habitable Zone Planet Finder (HPF), an R~50,000 near-infrared cross-dispersed radial velocity spectrograph that will be used to search for planets around M dwarfs. HPF is fiber-fed, operates in the zYJ bands, and uses a 1.7μm cutoff HAWAII-2RG (H2RG) NIR detector. We have constructed an end-to-end simulator that accepts as input a range of stellar models contaminated with telluric features and processes these through a simulated detector. This simulator accounts for the characteristics of the H2RG, including interpixel capacitance, persistence, nonlinearities, read noise, and other detector characteristics, as measured from our engineering-grade H2RG. It also implements realistic order curvature. We describe applications of this simulator including optimization of the fiber configuration at the spectrograph slit and selection of properties for a laser frequency comb calibration source. The simulator has also provided test images for development of the HPF survey extraction and RV analysis pipeline and we describe progress on this pipeline itself, which will implement optimal extraction, laser frequency comb and emission lamp wavelength calibration, and cross-correlation based RV measurement.

MASCARA, the Multi-site All-Sky CAmeRA, consists of several fully-automated stations distributed across the globe. Its goal is to find exoplanets transiting the brightest stars, in the V = 4 to 8 magnitude range, currently probed neither by space- nor by ground-based surveys. The nearby transiting planet systems that MASCARA is expected to discover will be key targets for future detailed planet atmosphere observations. Each station contains five wide-angle cameras monitoring the near-entire sky at each location. Once fully deployed, MASCARA will provide a nearly continuous coverage of the dark sky, down to magnitude 8, at sub-minute cadence. Effectively taking an image of the full sky every 6.4 seconds, MASCARA will produce approximately 500 GB of raw data per night, per station. This data needs to be processed in order to produce calibrated light curves, for up to ~40,000 stars down to magnitude 8 and with a signal-to-noise-ratio of better than 100. The aim of the data reduction pipeline is to process the data locally and in real time, both to immediately have quality control, as well as to prevent a data back-log. Although the cameras are fixed and the stars are therefore drifting over the CCDs, MASCARA is a targeted mission. Data processing consists of three main steps: 1. Compute a complete astrometric solution to sub-pixel level for each exposure and extracting postage stamps for each of the stars in the field of view. 2. Perform accurate photometry on each of the postage stamps, including back-ground subtraction and identification of errors in the photometry due to bad pixels, satellites, air planes or Laser Guide Stars. 3. Remove fluctuations on time scales typical for transits, i.e., several hours, caused by for example the camera and atmospheric transmission, color variations in stars and pixel-to-pixel gain fluctuations. Photometry on short time scales already shows noise levels close to the photon noise limit, and using a combination of calibration and relative photometry the red-noise component can be reduced to close to this photon noise limit, allowing for semi-automated identification of exo-planet transits. This paper discusses the data handling, processing and calibration and shows the first results of the pipeline.

The Herschel Space Observatory enabled a deep and detailed look into the far-infrared universe and even though the mission ended in May 2013, the rich archive is full of data to be analysed. The Herschel data reduction pipelines have progressed to give good results for most types of observations, but for other, more specialized programmes, improved image reconstruction tools and methods need to be applied to fully exploit the telescope's unique sensitivity and spatial resolution. This is the case for post-main-sequence objects observed with Her- schel /PACS as part of the MESS sample. Here, the standard pipeline as well as most map-makers cannot handle the bright central source surrounded by faint dust emission well. We compare the six standard map-making tools for Herschel observations and show how an improved astrometry can produce better maps. Our data processing steps can be applied to the standard pipeline as well as to external mappers based on inverse techniques.

Here we demonstrate a novel lucky imaging camera which is designed to produce diffraction-limited imaging using small telescopes similar to ones used by many academic institutions for outreach and/or student training. We present a design that uses a Meade 12” SCT paired with an Andor iXon fast readout EMCCD. The PSF of the telescope is matched to the pixel size of the EMCCD by adding a simple, custom-fabricated, intervening optical system. We demonstrate performance of the system by observing both astronomical and terrestrial targets. The astronomical application requires simpler data reconstruction techniques as compared to the terrestrial case. We compare different lucky imaging registration and reconstruction algorithms for use with this imager for both astronomical and terrestrial targets. We also demonstrate how this type of instrument would be useful for both undergraduate and graduate student training. As an instructional aide, the instrument can provide a hands-on approach for teaching instrument design, standard data reduction techniques, lucky imaging data processing, and high resolution imaging concepts.

We describe observational operations and data reduction for the science instrument FIFI-LS (Field Imaging Far Infrared Line Spectrometer) onboard SOFIA (Stratospheric Observatory for Infrared Astronomy). First, the observation strategy is explained, which plans all the various observing modes and parameters based on the targets and the limitations of the observatory and instrument. Next, the observations must be created in a format readable by instrument control software, via a system of algorithms. Once the observations have been planned and prepared, they must be scheduled, executed and analysed, and this process is outlined. The data reduction system which processes the results from these observations, beginning from retrieving raw data, to obtaining a FITS file data cube readable by analysis programs, is described in detail.

High-resolution infrared spectroscopy plays an important role in astrophysics from the search for exoplanets to cosmology. Yet, many existing infrared spectrographs are limited by a rather small simultaneous wavelength coverage. The AO assisted CRIRES instrument, installed at the ESO VLT on Paranal, is one of the few IR (0.92-5.2 μm) highresolution spectrographs in operation since 2006. However it has a limitation that hampers its efficient use: the wavelength range covered in a single exposure is limited to ~15 nanometers. The CRIRES Upgrade project (CRIRES+) will transform CRIRES into a cross-dispersed spectrograph and will also add new capabilities. By introducing crossdispersion elements the simultaneously covered wavelength range will be increased by at least a factor of 10 with respect to the present configuration, while the operational wavelength range will be preserved. For advanced wavelength calibration, new custom made absorption gas cells and etalons will be added. A spectro-polarimetric unit will allow one for the first time to record circularly polarized spectra at the highest spectral resolution. This will be all supported by a new data reduction software which will allow the community to take full advantage of the new capabilities of CRIRES+.

In the determination of the laser-induced damage threshold of optics, the correct estimation of damage probabilities is essential. In this publication, a simple procedure based on physical considerations is proposed to optimize the calculation of the damage probabilities by using a cumulative algorithm. The predicted status of test sites at higher and lower fluences than actually tested provides the basis for a new data reduction. It is shown that the proposed algorithm increases the statistically relevant amount of data per fluence interval dQi by using virtual test sites. Thus, the uncertainty σi in the calculation of the damage probabilities is reduced significantly and the subsequent linear regression of the damage probabilities will have a reduced least squared error. Non-linear regression of the damage probability according to defect-induced damage models as published numerous times in recent years are also performed to utilize a better confidence level which will be shown exemplarily.

Combined reflection and transmission ellipsometry of film-substrate systems provides a wealth of experimental information that proves helpful with extracting the system parameters. In such a technique, both the reflection and transmission ellipsometric functions are simultaneously measured. The technique itself requires a special design of the sample for fixed and for multiple angles of incidence measurements. The data reduction could be done using numerical methods which are tedious and time consuming resulting in an overall slower technique. A closed-form inversion for the system parameters (film thickness, film optical constant, and substrate optical constant) would render a fast technique that is suitable for real-time applications. The sample used is a three-film-thickness sample and measurements are carried out at two angles of incidence. Real simple closed-form equations are derived through successive transformations and algebraic manipulations to obtain the optical constants of the film and the substrate, in addition to the film thickness. We propose the use of obtained several values of the film thickness to provide a measure of the accuracy of the experimental measurements. In addition, the special case of a bare-substrate system is considered, and the use of the several values of the substrate refractive index to provide a measure of the accuracy of the experimental measurements in such a case is also proposed. A simple software program, with a limited number of code lines, is developed and tested yielding perfect results.

Though many materials behave approximately as greybodies across the long-wave infrared (LWIR) waveband, certain important infrared (IR) scene modeling materials such as brick and galvanized steel exhibit more complex optical properties 1 . Accurately describing how non-greybody materials interact relies critically on the accurate incorporation of the emissive and reflective properties of the in-scene materials. Typically, measured values are obtained and used. When measured using a non-imaging spectrometer, a given material’s spectral emissivity requires more than one collection episode, as both the sample under test and a standard must be measured separately. In the interval between episodes changes in environment degrade emissivity measurement accuracy. While repeating and averaging measurements of the standard and sample helps mitigate such effects, a simultaneous measurement of both can ensure identical environmental conditions during the measurement process, thus reducing inaccuracies and delivering a temporally accurate determination of background or ‘down-welling’ radiation. We report on a method for minimizing temporal inaccuracies in sample emissivity measurements. Using a LWIR hyperspectral imager, a Telops Hyper-Cam 2 , an approach permitting hundreds of simultaneous, calibrated spectral radiance measurements of the sample under test as well as a diffuse gold standard is described. In addition, we describe the data reduction technique to exploit these measurements. Following development of the reported method, spectral reflectance data from 10 samples of various materials of interest were collected. These data are presented along with comments on how such data will enhance the fidelity of computer models of IR scenes.

Detailed knowledge of instrument parameters and observing conditions is crucial for the achievement of micro- arcsecond precision and accuracy. It has come to be a key ingredient for optimal definition of data reduction and calibration procedures, since the variation of instrumental response over the field of view with wavelength and in time is both critical and often unavoidable. With this work we provide an overview of Astrometric Instrument Model (AIM) system within the Astrometric Verification Unit for the reduction of the Gaia data. We recall on the original motivations for its development, the changes occurred during the last two years and the actual AIM structure, pointing out the most critical parts in relation to the modeling of the astrometric instrument and of the scientific treatment of the Gaia data. While waiting for the Gaia operations to start, we present first results of AIM system from the on-going testing campaign of the Gaia data reduction software systems.

MUSE, the Multi Unit Spectroscopic Explorer, 1 is an integral-field spectrograph under construction for the ESO VLT to see first light in 2013. It can record spectra of a 1′x1′ field on the sky at a sampling of 0″.2x0″.2, over a wavelength range from 4650 to 9300A. The data reduction for this instrument is the process which converts raw data from the 24 CCDs into a combined datacube (with two spatial and one wavelength axis) which is corrected for instrumental and atmospheric effects. Since the instrument consists of many subunits (24 integral-field units, each slicing the light into 48 parts, i. e. 1152 regions with a total of almost 90000 spectra per exposure), this task requires many steps and is computationally expensive, in terms of processing speed, memory usage, and disk input/output. The data reduction software is designed to be mostly run as an automated pipeline and to fit into the open source environment of the ESO data flow as well as into a data management system based on AstroWISE. We describe the functionality of the pipeline, highlight details of new and unorthodox processing steps, discuss which algorithms and code could be used from other projects. Finally, we show the performance on both laboratory data as well as simulated scientific data.

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is a blind spectroscopic survey to map the evolution of dark energy using Lyman-alpha emitting galaxies at redshifts 1:9 < z < 3:5 as tracers. The survey instrument, VIRUS, consists of 75 IFUs distributed across the 22-arcmin field of the upgraded 9.2-m HET. Each exposure gathers 33,600 spectra. Over the projected five year run of the survey we expect about 170 GB of data per night. For the data reduction we developed the Cure pipeline. Cure is designed to automatically find and calibrate the observed spectra, subtract the sky background, and detect and classify different types of sources. Cure employs rigorous statistical methods and complete pixel-level error propagation throughout the reduction process to ensure Poisson-limited performance and meaningful significance values. To automate the reduction of the whole dataset we implemented the Cure pipeline in the Astro-WISE framework. This integration provides for HETDEX a database backend with complete dependency tracking of the various reduction steps, automated checks, and a searchable interface to the detected sources and user management. It can be used to create various web interfaces for data access and quality control. Astro-WISE allows us to reduce the data from all the IFUs in parallel on a compute cluster. This cluster allows us to reduce the observed data in quasi real time and still have excess capacity for rerunning parts of the reduction. Finally, the Astro-WISE interface will be used to provide access to reduced data products to the general community.

The core task of the Gaia mission is the solution of the Global Astrometric Sphere, which is providing the materialization of the astrometric reference frame for the catalog that will be the main outcome of the mission. Given the absolute character of the measurements, the Gaia Data Processing and Analysis Consortium (DPAC) has decided to replicate a dedicated version of this task, together with two other ones selected for their mission criticality, in an Astrometric Verification Unit (AVU). This task, named Global Sphere Reconstruction (GSR), focusses on the importance of having an implementation of the astrometric sphere solution from a well-defined subset of objects, based on an independent astrometric model as well as on a different solution algorithm. We analyze here these two aspects in the context of the GSR implementation at the Data Processing Center of Torino (DPCT) and the solution to implement the most computationally intensive part of the pipeline as a High-Performance Computing module.

The Multi Unit Spectroscopic Explorer (MUSE) instrument is a second-generation integral-field spectrograph in development for the Very Large Telescope (VLT), operating in the visible and near IR wavelength range (465-930 nm). Given the complexity of MUSE we have developed an instrument numerical simulator, which includes the whole chain of acquisition from the atmosphere down to the telescope and including the detectors, and taking into account both optical aberrations and diffraction effects, by propagating a wavefront through the instrument, according to the Fourier optics concept. This simulator is used to produce simulated exposures, in order to develop the data reduction software and to develop and validate the test procedures of the assembly, integration and tests phase. The MUSE instrument is currently being integrated in CRAL, and first real exposures have been taken. This paper compares and analyses the differences between the real data and the numerical simulations, in order to improve the instrument simulator and make it more realistic.

The Spectral Energy Distribution (SED) Machine is an Integral Field Unit (IFU) spectrograph designed specifically to classify transients. It is comprised of two subsystems. A lenselet based IFU, with a 26" × 26" Field of View (FoV) and ∼ 0.75" spaxels feeds a constant resolution (R∼100) triple-prism. The dispersed rays are than imaged onto an off-the-shelf CCD detector. The second subsystem, the Rainbow Camera (RC), is a 4-band seeing-limited imager with a 12.5' × 12.5' FoV around the IFU that will allow real time spectrophotometric calibrations with a ∼ 5% accuracy. Data from both subsystems will be processed in real time using a dedicated reduction pipeline. The SED Machine will be mounted on the Palomar 60-inch robotic telescope (P60), covers a wavelength range of 370 − 920nm at high throughput and will classify transients from on-going and future surveys at a high rate. This will provide good statistics for common types of transients, and a better ability to discover and study rare and exotic ones. We present the science cases, optical design, and data reduction strategy of the SED Machine. The SED machine is currently being constructed at the Calofornia Institute of Technology, and will be comissioned on the spring of 2013.

Integral-field spectrograph (IFS) instruments are well suited to observe extended and faint objects, such as planetary nebulae and galaxies. A result of such observations are large quantities of raw data, which mostly require an expert to derive accurate scientific spectra. Most instruments handle up to several thousand spectra simultaneously, using a unique file format, together with numerous instrument-specific issues, which only an experienced expert can resolve. p3d is an open source processing tool that is designed to handle raw data of any fiber-fed IFS, reducing IFS data quickly, easily, and accurately. Separate tools are available that handle many tasks including cosmic-ray hit rejection in single spectrum images, the combination of images, tracing of spectra on the detector, determination of spatial profiles of any shape, handling of images for flat fielding, dierent versions of spectrum extraction, combination of multi-detector data, and correction for atmospheric dierential refraction. The same approach and code is used with all instruments. No license is required when using p3d, even though it is based on the proprietary software IDL; this is made possible through precompiled binary files that are distributed together with the source code. p3d has been much improved with numerous releases since the first version early in 2010. Here we present the latest capabilities of a nearly complete program.

Adaptive Optics (AO) images are characterized by structured Point Spread Function (PSF), with sharp core and extended halo, and by significant variations across the field of view. In order to enable the extraction of high-precision quantitative information and improve the scientific exploitation of AO data, efforts in the PSF modeling and in the integration of suitable models in a code for image analysis are needed. We present the current status of a study on the modeling of AO PSFs based on observational data taken with present telescopes (VLT and LBT). The methods under development include parametric models and hybrid (i.e. analytical / numerical) models adapted to various types of PSFs that can show up in AO images. The specific features of AO data, such as the mainly radial variation of the PSF with respect to the guide star position in single-reference AO, are taken into account as much as possible. The final objective of this project is the development of a flexible software package, based on the Starfinder code (Diolaiati et Al 2000), specifically dedicated to the PSF estimation and to the astrometric and photometric analysis of AO images with complex and spatially variable PSF. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Since the beginning of the ESPRESSO (Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations) project, it has been recognized that the expected challenging scientific results can be achieved only if an integrated view of the end-to-end operations is properly tackled. Hunting for rocky exoplanets and/or studying the possible variations of physical constants requires not only a dedicated, state-of-the-art spectrograph in terms of hardware and optics, but also a tailored observation strategy, data reduction pipeline and data analysis tools (ESPRESSO will be the first ESO instrument for which a customized Data Analysis Software will be provided to the community by the Consortium). In this paper we present the planned data flow system (DFS) for ESPRESSO as emerged after the Preliminary Design Review held in November 2011. Main requirements in terms of observation strategy/preparation and data reduction/analysis are analyzed and the corresponding foreseen (conceptual) design, able to fulfill them, discussed. Eventually, peculiarities and challenges needed to adapt ESPRESSO DFS in the pre-existing ESO/VLT DFS framework are outlined.

A lunar scintillometer, LuSci, is an inexpensive and robust instrument which deploys a linear array of photodiodes pointed toward the moon to measure scintillation produced by atmospheric turbulence. Covariances between the signals from the photodiodes are analyzed to derive estimates of the turbulence profile within a few hundred meters above the ground. Instrument parameters and phase of the moon are taken into account. This method has been used for site testing and monitoring. We present the development of a new LuSci instrument used to validate the ground-layer turbulence distribution measured from the laser wavefront sensor signals of the Ground Layer Adaptive Optics system at the MMT. The near-simultaneous measurements are used to characterize the performance of the GLAO system. We describe the instrument, its operation, approaches to data reduction, and use in performance characterization of a GLAO system.­

This paper addresses a method for extracting the convection speed and direction of aberrations present in wavefronts due to aero-optical turbulence over the pupil of a turret on the side of an airborne platform. The method is applied to data from the Airborne Aero-Optics Laboratory (AAOL). Such convection information is useful in designing feed-forward adaptive-optic approaches. The method makes use of a four-beam Malley probe technique derived by constructing a two-dimensional local convective velocity-distribution over the beam's aperture. This technique is based on extending the analysis of the Notre-Dame-developed Malley probe. Two wavefront datasets (Azimuth 157° and Elevation 40°; Azimuth 42° and Elevation 43°) from the AAOL are analyzed using the derived method, the first where the laser propagates through fully-separated flow and the second where the laser propagates through an attached-flow region. Finally, the two-dimensional Proper Orthogonal Decomposition is applied to one in-flight measured dataset to determine the spatial requirements of deformable mirrors in an adaptive-optics system. The paper concludes with a discussion that points out the usefulness of the two-dimensional velocity-distributions in characterizing the various flow structures which convect over the aperture.