astro space locator imaging software alexey rudnitskiy, victor zuga on behalf of astro space center...

Astro Space LocatorImaging Software

Alexey Rudnitskiy, Victor Zuga

On behalf of Astro Space Center (ASC LPI)Department Of Data Processing

School of Modern Astrophysics "Submillimeter astronomy“, Dolgoprudny, Russia, 2015

*Hesrchel image - Galactic Plane in Vulpecula

Introduction and Overview• Astro Space Locator (ASL) Software package has all necessary utilities and

applications for VLBI data processing, reduction, post-correlation analysis and imaging. This includes:– ASL Imager – imaging software with visual interface

• Fringe search utility• Fringe fitting utility• Calibration utilities• Multi-frequency synthesis utility

– ASL Editor –editor of correlated data with visual interface• Time and frequency averaging utilities

– ASL CalEdit – ANTAB calibration files with visual interface– ASL Data Formats Converters – UVX to IDI-FITS, IDI-FITS to UVX, etc.

Supported OS: Microsoft Windows (95/98/ME/2000/XP/Vista/7/8)Linux (now using in test mode portable WINE package, tested on

Fedora 19/20, Ubuntu)

Data formats

• ASL Imaging Software accepts the following data formats:– UVX correlated data format– IDI-FITS correlated data format– UVFITS data format

Main operational format is ASL internal UVX format. Software is capable of converting IDI-FITS, UVFITS to UVX and FITS images to EXM (external map file) correspondingly.

Interface

Convenient and user friendly graphical interface.

Using the interactive image reduction.

Data editing and reduction

ASL Editor is capable of visualizing and visual editing of all correlated data stored in the UVX file, including:

Telescope and/or baseline editing/removingVisibility, Phase editing/flagging/removing/adjustmentVisibility vs. baseline projection fast review and approximationFrequency/Time averagingData statistics and other…

Fringe fitting

ASL Fringe Fitting utility supports global fringe fitting with adjustable number of closing,external model map, automatical reference telescope search, set of different apply parameters,

including adjustable solution interval, FFT map size, phase correction, etc.

Data calibration overview

• Software package include the following calibration utilities:

– Amplitude calibration • Using AIPS ANTAB calibration files

– Bandpass calibration– Reference source phase calibration– Self-calibration

Amplitude calibration• Supports AIPS ANTAB calibration files with

system temperature or SEFD measurements

Self-calibration

Self-calibration utility provides flexible adjustment of multiple parameters.Capable of step by step calibration and calibration

automatically within the defined number of iterations.

Imaging

ASL Imager uses standard approach for image restoration known as CLEAN algorithm.

Multi-frequency synthesis

ASL software includes utility for multi-frequency synthesis (MFS).MFS algorithms provide capability of merging series of observations which were done at

different frequencies. This approach can improve the UV coverage up to 30% and increases the dynamic range of the output image.

Thank you for your attention!

Astro Space Center Department Of Data Processing web-page: http://radioastron.ru/index2.php?engdep=6

Contacts: Alexey Rudnitskiy e-mail: arud@asc.rssi.ru, almax1024@gmail.com

Victor Zuga e-mail: : zuga@asc.rssi.ru, vzouga@gmail.com

*Hesrchel image - Galactic Plane in Vulpecula

On behalf of ASC LPI Department Of Data Processing, which includes: Sergey Likhachev, Vladimir Kostenko, Andrey Andrianov, Igor Girin, Andrey Lyakhovets.