12 research outputs found
A public data archive for the Italian radio telescopes
The amount of data delivered by modern instrumentation and observing techniques is bringing radio astronomy in the era of Big Data, and the nowadays widely adopted Open Data policies allow free and open access to data from many radio astronomy facilities. A fundamental ingredient to enable Open Science in the radio astronomical community and to engage also public participation (the so called Citizen Science) is thus the availability of public archives in which data can be accessed and searched with modern software tools. A web-based, VO-compliant public archive has been built to host data from the Italian radio telescopes managed by the National Institute for Astrophysics (INAF). The archive main features consist in the capability to handle the various types of data coming from the different observing instrumentation at the telescopes; the adoption of a policy to guarantee the data proprietary period; the accessibility of data through a web interface and the adoption of VO standards to allow for successful scientific exploitation of the archive itself in the data mining era. We present the progress status of the public Data Archive for the Italian radio telescopes being developed to provide the international community with a state-of-the-art archive for radio astronomical data
Radio data archiving system
Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly
Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes
We present a project to implement a national common strategy for the
mitigation of the steadily deteriorating Radio Frequency Interference (RFI)
situation at the Italian radio telescopes. The project involves the Medicina,
Noto, and Sardinia dish antennas and comprised the definition of a coordinated
plan for site monitoring as well as the implementation of state-of-the-art
hardware and software tools for RFI mitigation. Coordinated monitoring of
frequency bands up to 40 GHz has been performed by means of continuous
observations and dedicated measurement campaigns with fixed stations and mobile
laboratories. Measurements were executed on the frequency bands allocated to
the radio astronomy and space research service for shared or exclusive use and
on the wider ones employed by the current and under-development receivers at
the telescopes. Results of the monitoring campaigns provide a reference
scenario useful to evaluate the evolution of the interference situation at the
telescopes sites and a case series to test and improve the hardware and
software tools we conceived to counteract radio frequency interference. We
developed a multi-purpose digital backend for high spectral and time resolution
observations over large bandwidths. Observational results demonstrate that the
spectrometer robustness and sensitivity enable the efficient detection and
analysis of interfering signals in radio astronomical data. A prototype
off-line software tool for interference detection and flagging has been also
implemented. This package is capable to handle the huge amount of data
delivered by the most modern instrumentation on board of the Italian radio
telecsopes, like dense focal plane arrays, and its modularity easen the
integration of new algorithms and the re-usability in different contexts or
telescopes.Comment: 39 pages, 10 Figures and 7 Tables. INAF Technical Report n. 149
(2022). http://hdl.handle.net/20.500.12386/3208
KAFE: the Key-analysis Automated FITS-images Explorer
We present KAFE—the Key-analysis Automated FITS-images Explorer. KAFE is a web-based FITS
image postprocessing analysis tool designed to be applicable in the radio to sub-mm wavelength domain. KAFE
was developed to complement selected FITS files with metadata based on a uniform image analysis approach
as well as to provide advanced image diagnostic plots. It is ideally suited for data mining purposes and multiwavelength/multi-instrument data samples that require uniform data diagnostic criteria. We present the code structure and interface, the keyword definitions, the products generated for selected users’ science cases, and application examples
An Overview of the 2014 ALMA Long Baseline Campaign
A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to
make accurate images with resolutions of tens of milliarcseconds, which at
submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop
and test this capability, a Long Baseline Campaign (LBC) was carried out from
September to late November 2014, culminating in end-to-end observations,
calibrations, and imaging of selected Science Verification (SV) targets. This
paper presents an overview of the campaign and its main results, including an
investigation of the short-term coherence properties and systematic phase
errors over the long baselines at the ALMA site, a summary of the SV targets
and observations, and recommendations for science observing strategies at long
baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also
compared to VLA 43 GHz results, demonstrating an agreement at a level of a few
percent. As a result of the extensive program of LBC testing, the highly
successful SV imaging at long baselines achieved angular resolutions as fine as
19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now
possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the
Astrophysical Journal Letters; this version with small changes to
affiliation
The 2014 ALMA Long Baseline Campaign: An Overview
A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy
Macchina dei colori 2.0 - Navigando lungo lo spettro elettromagnetico
Il documento descrive la progettazione e realizzazione di un exhibit interattivo didattico, prodotto per il Centro Visite "M. Ceccarelli" (INAF-IRA), dedicato ad approfondimenti, in ambito astrofisico tanto quanto di "vita quotidiana", sulle diverse bande dello spettro elettromagnetico