3C84, BL Lac. Earth based VLBI test for the RADIOASTRON project

TL;DR

This paper reports on VLBI observations of 3C84 and BL Lac using multiple ground-based radio telescopes to test and validate the data processing and correlation methods for the RADIOASTRON space VLBI mission.

Contribution

It demonstrates the successful processing and correlation of VLBI data from multiple European and Russian antennas, validating ground-based systems for RADIOASTRON.

Findings

Successful data conversion into RDF format

Correlation results consistent across different correlators

Validation of ground-based VLBI systems for RADIOASTRON

Abstract

Results of processing of data of a VLBI experiment titled RAPL01 are presented. These VLBI observations were made on 4th February, 2010 at 6.28 cm between the 100-m antenna of the Max Planck Institute (Effelsberg, Germany), Puschino 22-m antenna (Astro Space Center (ASC), Russia), and two 32-m antennas of the Istituto di Radioastronomia di Bologna (Bologna, Italy) in Noto and Medicina. 2 well-known sources, 3C84 (0316+413), and BL Lac (2200+420) were included in the schedule of observations. Each of them was observed during 1 hour at all the stations. The Mark-5A registration system was used at 3 European antennae. The alternative registration system known as RDR (RADIOASTRON Data Recorder) was used in Puschino. The Puschino data were recorded in format RDF (RADIOASTRON Data Format). Two standard recording modes designed as 128-4-1 (one bit), and 256-4-2 (two bit) were used in the experiment. All the Mark-5A data from European antennae were successfully converted into the RDF format. Then, the correlation function was estimated at the ASC software correlator. A similar correlation function also was estimated at the Bonn correlator. The Bonn correlator reads Mark5A data, the RDF format was converted into Mark5B format before correlation. The goal of the experiment was to check the functioning and data analysis of the ground based radio telescopes for the RADIOASTRON SVLBI mission