Decoherence in LOFAR-VLBI beamforming

VLBI observations of Jupiter with the Initial Test Station of LOFAR and the Nançay Decametric Array

Aims. To demonstrate and test the capability of the next generation of low-frequency radio telescopes to perform high resolution observations across intra-continental baselines. Jupiter’s strong burst emission is used to perform broadband full signal cross-correlations on time intervals of up to hundreds of milliseconds. Methods. Broadband VLBI observations at about 20 MHz on a baseline of ∼ 50...

Bandpass Correction in LOFAR

This document describes how we correct the bandpass in the OnLine Application Processing pipeline (better known as " the Blue Gene/P correlator ").

Astrophysics in the LOFAR era

Lofar information system design

The Lofar Information System is a solution for Lofar Long Term Archive that is capable to store and handle PBs of raw and processed data. The newly created information system is based on Astro-WISE the information system for wide field astronomy. We review an adaptation of Astro-WISE for the new tasks and propose a generic solution for the publishing of the data from the Lofar Information Syste...

Detection of Lofar Lines

The problem of extracting spectral lines from sonar images is treated using a complete scheme that combines an edge detector with a line tracking process. That is, the edge detection process allows lter-ing the sonar image and nding a region (zero-crossings of the second derivative of the sonar image) that includes a spectral line. The founded region is then used to initialize and to limit the ...