Flexible Image Transport System File Research Articles

Fips: An OpenGL based FITS viewer

FITS (Flexible Image Transport System) is a common format for astronomical data storage. [1]. Even though astronomical data is now processed mostly using software, visual data inspection by a human is still important during equipment or software commissioning and while observing. We present Fips [2, 3], a cross-platform FITS file viewer released as open source software1. To the best of our knowledge, it is for the first time that the image rendering algorithms are implemented mostly on GPU (graphics processing unit). We show that it is possible to implement a fully-capable FITS viewer using OpenGL [4] interface, including movie support for representing 3D data. We also emphasise the advantages of using GPUs for efficient image handling.

AtomNeb: IDL Library for Atomic Data of Ionized Nebulae

Spectra emitted from ionized nebulae typically contain collisionally excited and recombination lines, which can be used to trace physical conditions and chemical abundances of the interstellar medium in our Galaxy and other galaxies. "AtomNeb" is a database containing atomic data stored in the Flexible Image Transport System (FITS) file format, including the data for collisionally excited and recombination lines generally observed in nebular astrophysics. The AtomNeb interface library is equipped with several application programming interface (API) functions developed in the Interactive Data Language (IDL), which can be also used in the GNU Data Language (GDL). This IDL library relies on the FITS file related IDL procedures from the IDL Astronomy User's library. The AtomNeb IDL library, together with the "proEQUIB" IDL library, can be used to perform plasma diagnostics and abundance analysis of emission lines from ionized gaseous nebulae.

Aflak: Visual programming environment enabling end-to-end provenance management for the analysis of astronomical datasets

This paper describes an extendable graphical framework, aflak, which provides a visualization and provenance management environment for the analysis of multi-spectral astronomical datasets. Via its node editor interface, aflak allows the astronomer to compose transforms on input datasets queryable from public astronomical data repositories, then to export the results of the analysis as Flexible Image Transport System (FITS) files, in a manner such that the full provenance of the output data be preserved and reviewable, and that the exported file be usable by other common astronomical analysis software. FITS is the standard of data interchange in astronomy. By embedding aflak’s provenance data into FITS files, we both achieve interoperability with existing software and full reproducibility of the process by which astronomers make discoveries.

Fips: An OpenGL based FITS viewer

FITS (Flexible Image Transport System) is a common format for astronomical data storage. It was first standardised in the early 1980s. Even though astronomical data is now processed mostly using software, visual data inspection by a human is still important during equipment or software commissioning and while observing. We present Fips, a cross-platform FITS file viewer open source software. To the best of our knowledge, it is for the first time that the image rendering algorithms are implemented mostly on GPU (graphics processing unit). We show that it is possible to implement a fully-capable FITS viewer using OpenGL interface. We also emphasise the advantages of using GPUs for efficient image handling.

The Galaxy Cluster Merger Catalog: An Online Repository of Mock Observations from Simulated Galaxy Cluster Mergers

Abstract We present the “Galaxy Cluster Merger Catalog.” This catalog provides an extensive suite of mock observations and related data for N-body and hydrodynamical simulations of galaxy cluster mergers and clusters from cosmological simulations. These mock observations consist of projections of a number of important observable quantities in several different wavebands, as well as along different lines of sight through each simulation domain. The web interface to the catalog consists of easily browsable images over epoch and projection direction, as well as download links for the raw data and a JS9 interface for interactive data exploration. The data are presented within a consistent format so that comparison between simulations is straightforward. All of the data products are provided in the standard Flexible Image Transport System file format. The data are being stored on the yt Hub (http://hub.yt), which allows for remote access and analysis using a Jupyter notebook server. Future versions of the catalog will include simulations from a number of research groups and a variety of research topics related to the study of interactions of galaxy clusters with each other and with their member galaxies. The catalog is located at http://gcmc.hub.yt.

Two-dimensional images of unstable infiltration in initially dry heterogeneous porous media in laboratory experiments

We provide a data set of unstable infiltration into initially dry homogeneous and heterogeneous porous media. The data set contains small 2D experiments (Exp. 3-11 in Table 12 of the associated manuscript) as well as selected experiments conducted in large tanks. For small 2D experiments, radiographic images are provided, while large 2D experiments are documented via RGB images. Datasets contain a reference image 0.* before the onset of finger formation, where the porous media in the domain, except for the upper fine layer, is completely dry. For the radiography dataset, the measured neutron intensity corresponds to I in Eq. [1-2] and the reference image “0.fits” corresponds to Idry in Eq. [2] of the manuscript. Datasets for radiography (Exp. 3-11) contain an additional empty empty.fits image where the flow cell is absent. Other filenames relate to time in seconds after onset of finger formation The radiography dataset (Exp. 3-11) is saved in the Flexible Image Transport System (FITS) format, which can be opened with common image processing tools such as ImageJ or computing environments such as Matlab. More information regarding the file format can be found at https://fits.gsfc.nasa.gov/fits_home.html. Each FITS file contains a 512 by 512 matrix of pixelwise measured neutron intensities [neutrons/(px*s)]. The dimensions of the pixels can be found in the table below. Fits files furthermore contain supporting information that has not been utilized in the manuscript but might prove useful, such as number of bits per data pixel and exposure time. For evaluation as conducted in the manuscript, the radiography raw data given in this dataset has been processed to eliminate the background noise with a wiener noise-removal filter. More Information on the radiography facility can be found at https://www.psi.ch/sinq/PublicationPolicyEN/NEUTRA.pdf.

HDFITS: Porting the FITS data model to HDF5

The FITS (Flexible Image Transport System) data format has been the de facto data format for astronomy-related data products since its inception in the late 1970s. While the FITS file format is widely supported, it lacks many of the features of more modern data serialization, such as the Hierarchical Data Format (HDF5). The HDF5 file format offers considerable advantages over FITS, such as improved I/O speed and compression, but has yet to gain widespread adoption within astronomy. One of the major holdbacks is that HDF5 is not well supported by data reduction software packages and image viewers. Here, we present a comparison of FITS and HDF5 as a format for storage of astronomy datasets. We show that the underlying data model of FITS can be ported to HDF5 in a straightforward manner, and that by doing so the advantages of the HDF5 file format can be leveraged immediately. In addition, we present a software tool, fits2hdf, for converting between FITS and a new `HDFITS' format, where data are stored in HDF5 in a FITS-like manner. We show that HDFITS allows faster reading of data (up to 100x of FITS in some use cases), and improved compression (higher compression ratios and higher throughput). Finally, we show that by only changing the import lines in Python-based FITS utilities, HDFITS formatted data can be presented transparently as an in-memory FITS equivalent.

Enhanced management of personal astronomical data with FITSManager

Although the roles of data centers and computing centers are becoming more and more important, and on-line research is becoming the mainstream for astronomy, individual research based on locally hosted data is still very common. With the increase of personal storage capacity, it is easy to find hundreds to thousands of FITS files in the personal computer of an astrophysicist. Because Flexible Image Transport System (FITS) is a professional data format initiated by astronomers and used mainly in the small community, data management toolkits for FITS files are very few. Astronomers need a powerful tool to help them manage their local astronomical data. Although Virtual Observatory (VO) is a network oriented astronomical research environment, its applications and related technologies provide useful solutions to enhance the management and utilization of astronomical data hosted in an astronomer’s personal computer. FITSManager is such a tool to provide astronomers an efficient management and utilization of their local data, bringing VO to astronomers in a seamless and transparent way. FITSManager provides fruitful functions for FITS file management, like thumbnail, preview, type dependent icons, header keyword indexing and search, collaborated working with other tools and on-line services, and so on. The development of the FITSManager is an effort to fill the gap between management and analysis of astronomical data.

Definition of the Flexible Image Transport System (FITS), version 3.0

The Flexible Image Transport System (FITS) has been used by astronomers for over 30 years as a data interchange and archiving format; FITS files are now handled by a wide range of astronomical software packages. Since the FITS format definition document (the standard) was last printed in this journal in 2001, several new features have been developed and standardized, notably support for 64-bit integers in images and tables, variable-length arrays in tables, and new world coordinate system conventions which provide a mapping from an element in a data array to a physical coordinate on the sky or within a spectrum. The FITS Working Group of the International Astronomical Union has therefore produced this new Version 3.0 of the FITS standard, which is provided here in its entirety. In addition to describing the new features in FITS, numerous editorial changes were made to the previous version to clarify and reorganize many of the sections. Also included are some appendices which are not formally part of the standard. The FITS standard is likely to undergo further evolution, in which case the latest version may be found on the FITS Support Office Web site at http://fits.gsfc.nasa.gov/, which also provides many links to FITS-related resources.

Monte Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis

Abstract We have developed a framework for the Monte Carlo simulations of X-Ray Telescope (XRT) and X-ray Imaging Spectrometer (XIS) on board Suzaku, mainly for the scientific analysis of spatially and spectroscopically complex celestial sources. A photon-by-photon instrumental simulator is built on the ANL platform, which has been successfully used in ASCA data analysis. The simulator has a modular structure, in which the XRT simulation is based on a ray-tracing library, while the XIS simulation utilizes a spectral “Redistribution Matrix File” (RMF), generated separately by other tools. Instrumental characteristics and calibration results [e.g., XRT geometry, reflectivity, mutual alignments, thermal shield transmission, build-up of the contamination on the XIS optical blocking filters (OBF)] are incorporated as completely as possible. Most of this information is available in the form of FITS (Flexible Image Transport System) files in the standard calibration database (CALDB). This simulator can also be utilized to generate an “Ancillary Response File” (ARF), which describes the XRT response and the amount of OBF contamination. An ARF is dependent on the spatial distribution of the celestial target and the photon accumulation region on the detector, as well as the observing conditions, such as the observation date and satellite attitude. We describe the principles of the simulator and the ARF generator, and demonstrate their performance compared with in-flight data.