Radiotelescopi di Medicina : LOFAR

HOME LOFAR 5. Science


5. Science

1. Introduction

LOFAR has three main modes of operation for radio astronomical observations:


Aperture Synthesis Mode: station beams are correlated and visibility data are pre-calibrated, integrated and post-processed to get to a manageable data-rate for archiving and exporting, and suitable for imaging. Each station is planned to have a field of view and a sensitivity suitable to observe at any time a certain number of primary calibrators aiming to a full calibration of the data so that the correlated interferometric dataset can be inverted to provide a direct measure of the sky brightness. Weaker sources will be extracted once the strongest ones (mostly calibrators) have been subtracted out.

2. The Core
3.Technical Details
3.1 The System
3.2 Data processing
3.3 Antennas spec.
4.Lofar at Medicina
4.1 Baseline extension
4.2 Lofar Kit
4.3 Superstation
5. Science

Tied Array Mode: Tied Array Mode observations produce a possibly large number of tied array beams from all receptors in the instrument, or a subset thereof. The resulting voltage sum output of each tied array beam may be presented either as a series of spectral channels or transformed back into a time series. More dedicated data products are possible as well: e.g. for flux density monitoring of single pixels on the sky. In this operation mode a large quantity of raw data is collected; however time averaging can be applied to each of many beams to achieve the necessary compression.

Transient Detection Mode: for Transient Detection Modes, the final data-products are typically event-lists, possibly combined with raw time-series replayed from station level data-buffers. Buffered data may be (re-)processed centrally, resulting in more specific data-products.








                                                                                                G. Bianchi