OPTICON currently supports a Joint Research Activity (JRA) dedicated to providing easy to use image reconstruction algorithms for optical/IR interferometric data. This JRA aims to provide state-of-the-art image reconstruction methods with a common interface and comprehensive documentation to the community. These tools will provide the capability to compare the results of using different settings and algorithms in a consistent and unified way. The JRA is also providing tutorials and sample datasets to introduce the principles of image reconstruction and illustrate how to use the software products. We describe the design of the imaging tools, in particular the interface between the graphical user interface and the image reconstruction algorithms, and summarise the current status of their implementation.
The Optical interferometry DataBase (OiDB) aims at facilitating the access to science-ready data provided by various existing or decommissioned interferometers. The first version of OiDB has been released in June 2015. Today it contains more than 5000 OIFITS datafiles including the full collection of PIONIER data since 2011. All these reduced data are made publicly available and easily downloadable from OiDB. After presenting the characteristics of OiDB, we analyse how the community made use of it during this first year of operation and how we will improve it.
We report on a database service that allows users to query calibrated optical interferometry data (OIFITS format) as well as regularly-updated observation logs obtained with a wide range of interferometric instruments. It widely uses Virtual Observatory tools to increase diffusion and operability. In this contribution, we present the characteristics and functionalities of the first global optical interferometry archive service.
Observing reference stars with a known diameter is almost the only possibility to calibrate optical interferometry observations. The JMMC Calibrator Workgroup develops methods to ascertain the angular diameter of stars since 2000 and provides this expertise in the SearchCal software and associated databases. We provide on a regularly basis the JSDC, a catalogue of such stars, and an open access to our server that dynamically finds calibrators near science objects by querying CDS hosted catalogs. Here we propose a novel approach in the estimation of angular stellar diameters based on observational quantities only. It bypasses the knowledge of the visual extinction and intrinsic colors, thanks to the use of absorption free pseudo-colors (AFC) and the spectral type number on the x-axis. This new methodology allows to compute the angular diameter of 443 703 stars with a relative precision of about 1%. This calibrator set will become after filtering the next JSDC release.
This poster advertizes the Jean-Marie Mariotti Center software tools, databases and services aimed at facilitating the use of optical interferometry worldwide such as preparation of observations, data reduction and data analysis. Its mission and organization are presented before listing the current software suite. Finally some facts and perspectives are mentioned.
Optical long baseline interferometry is a technique that has generated almost 850 refereed papers to date.
The targets span a large variety of objects from planetary systems to extragalactic studies and all branches of
stellar physics. We have created a database hosted by the JMMC and connected to the Optical Long Baseline
Interferometry Newsletter (OLBIN) web site using MySQL and a collection of XML or PHP scripts in order to
store and classify these publications. Each entry is defined by its ADS bibcode, includes basic ADS informations
and metadata. The metadata are specified by tags sorted in categories: interferometric facilities, instrumentation,
wavelength of operation, spectral resolution, type of measurement, target type, and paper category, for example.
The whole OLBIN publication list has been processed and we present how the database is organized and can
be accessed. We use this tool to generate statistical plots of interest for the community in optical long baseline
We present the third release of the AMBER data reduction software by the JMMC. This software is based on
core algorithms optimized after several years of operation. An optional graphic interface in a high level language
allows the user to control the process step by step or in a completely automatic manner. Ongoing improvement
is the implementation of a robust calibration scheme, making use of the full calibration sets available during
the night. The output products are standard OI-FITS files, which can be used directly in high level software
like model fitting or image reconstruction tools. The software performances are illustrated on a full data set of
calibrators observed with AMBER during 5 years taken in various instrumental setup.
The JMMC1 Calibrator Workgroup has long developed methods to ascertain the angular diameter of stars, and provides
this expertise in the SearchCal2 software. SearchCal dynamically finds calibrators near science objects by querying CDS3
hosted catalogs according to observational parameters. Initially limited to bright objects (K magnitude ≤ 5.5), it has been
upgraded with a new method providing calibrators without any magnitude limit but those of queried catalogs. We
introduce here a new static catalog of stellar diameters, containing more than 38000 entries, obtained from SearchCal
results aggregation on the whole celestial sphere, complete for all stars with HIPPARCOS4 parallaxes. We detail the
methods and tools used to produce and study this catalog, and compare the static catalog approach with the dynamical
querying provided by SearchCal engine. We also introduce a new Virtual Observatory service, enabling the reporting of,
and querying about, stars flagged as "bad calibrators" by astronomers, adding this ever-growing database to our
LITpro is a software for fitting models on data obtained from various stellar optical interferometers, like the VLTI. As a
baseline, for modeling the object, it provides a set of elementary geometrical and center-to-limb darkening functions, all
combinable together. But it is also designed to make very easy the implementation of more specific models with their
own parameters, to be able to use models closer to astrophysical considerations. So LITpro only requires the modeling
functions to compute the Fourier transform of the object at given spatial frequencies, and wavelengths and time if needed.
From this, LITpro computes all the necessary quantities as needed (e.g. visibilities, spectral energy distribution, partial
derivatives of the model, map of the object model). The fitting engine, especially designed for this kind of optimization, is
based on a modified Levenberg-Marquardt algorithm and has been successfully tested on real data in a prototype version.
It includes a Trust Region Method, minimizing a heterogeneous non-linear and non-convex criterion and allows the user
to set boundaries on free parameters. From a robust local minimization algorithm and a starting points strategy, a global
optimization solution is effectively achieved. Tools have been developped to help users to find the global minimum. LITpro
is also designed for performing fitting on heterogeneous data. It will be shown, on an example, how it fits simultaneously
interferometric data and spectral energy distribution, with some benefits on the reliability of the solution and a better
estimation of errors and correlations on the parameters. That is indeed necessary since present interferometric data are
We present ASPRO-VLTI, the newly developed JMMC software that will allow astronomers to prepare observations with both first-generation VLTI instruments, AMBER and MIDI. This software has been specifically designed to hide as much as possible instrument complexity and should permit to focus primarily on the science objectives. The targeted users are all astronomers interested in observing with VLTI but with limited interferometric background. It should be particularly well suited for the preparation of ESO-VLTI Phase I proposals. The user can define its target model, choose observational parameters and check if the observations will match its scientific goals. Output
quantities and plots can be used for observation proposals.
WIRCam (Wide-field InfraRed Camera) is a near-infrared (0.9-2.4 microns) camera developed for the prime focus of the Canada France Hawaii Telescope (CFHT), a 3.6-m telescope located on Mauna Kea, Hawaii. WIRCam is based on 4 x 2048x2048 HAWAII2RG arrays, developed by Rockwell. The camera provides a 0.3"/pixel sampling, and the close packaging of the detectors allows to cover an almost contiguous field-of-view of 20.5' x 20.5'. All optical elements are assembled in a cryovessel and cooled down to 85K by a He closed cycle cryogenerator. The two filter wheels have capacity for 8 filters (110 mm in diameter), cooled at low temperature together with the Lyot stop. These wheels are mounted on sapphire ball bearings and powered by external motors. Passive spring indexers define their positioning. A fused-silica tip/tilt plate powered by voice coil type motors provides image stabilization in front of the cryovessel. It compensates for flexures as well as for low frequency telescope oscillations from wind shake. This paper describes the overall architecture of the camera, giving the optical estimated performances and details some specific points of the design such as filter wheels, thermal connections, etc.
ASPRO (Astronomical Software to PrepaRe Observations) is a software tool built and maintained by the Jean-Marie Mariotti Center (JMMC) that provides means to prepare and test the validity of observations on various existing interferometers, noticeably the VLTI. Concerning our web development of ASPRO, our new generic GUI system is a fast light solution to bring a GUI to the applications or languages that haven't such capability. The toolkit is conceptually divided into three parts. The main application is considered as a server. The client handles widgets and graphic presentations and the user interactions according to the applications. One gateway system manages the data flow. Then messages are generated by applications and addressed to the client. The client presents informations to the user and returns back values or commands. This paper describes the overall architecture. It details the application's interfaces. It lists widgets capabilities and graphic functions. It presents features of our first JAVA client which supports XML exchanges. Finally we present how several distant applications are linked to one client but also between themselves.