SETI-ITALIA 2008: On-going searches and future prospects S. Montebugnoli a,Ã , M. Bartolini a , G. Bianchi a , C. Cosmovici c , J. Monari a , A. Orlati a , F. Perini a , S. Pluchino a , G. Pupillo b , E. Salerno a , F. Schillir  o a , L. Zoni a a Istituto Nazionale di Astroﬁsica (INAF) – Istituto di Radioastronomia (IRA), Bologna, Italy b Istituto Nazionale di Astroﬁsica (INAF) – Osservatorio Astronomico di Torino (OATO), Torino, Italy c Istituto Nazionale di Astroﬁsica (INAF) – Istituto di Fisica dello Spazio Interplanetario (IFSI), Roma, Italy article info Article history: Received 10 August 2009 Received in revised form 3 March 2010 Accepted 4 March 2010 Available online 10 April 2010 Keywords: Radioastronomy Data acquisition Signal extraction Algorithms Fast data processing SETI abstract The Medicina Radioastronomical Station is located nearby Bologna, in Italy. It consists of two receiving antennas currently dedicated to the astronomical research at radio frequencies. The 32 m diameter parabolic dish performs observations from 1.4 to 22 GHz whereas the Northern Cross (a 30.000 m 2 wide T-shaped array transit antenna) works at 408 MHz. So far SETI observations have been performed using a SERENDIP IV high resolution spectrometer connected to the parabolic antenna. Data acquisition were performed meanwhile the antenna was employed in ordinary astronomical observa- tions (piggy-back mode). An innovative method to search for possible extraterrestrial signals could be provided by using the UHF Northern Cross transit telescope. In this paper observational modalities and the required technological set-up are investigated. & 2010 Elsevier Ltd. All rights reserved. 1. Introduction The Medicina Radioastronomy Station (MRS) is located nearby Bologna (Italy). It is one of the three radio observatories of the Istituto di Radioastronomia (IRA) of the Italian Istituto Nazionale di Astroﬁsica (INAF). MRS is provided with two radiotelescopes: the 32 m dish, mainly dedicated to Very Long Baseline Interferometry (VLBI) observations and the Northern Cross, a large T-shaped parabolic/cylindrical antenna with an area of 30.000 m 2 (Fig. 1). The parabolic VLBI antenna is charachterized by a collecting area of 800 m 2 and it works in the radio astronomical bands included in the 1.4–23 GHz range. It is equipped with a very high frequency resolution SERENDIP IV real time spectrometer (0.6 Hz) fully dedicated to the SETI program. This backend operates in piggy-back mode (i.e. data are collected meanwhile the antenna is employed in the ordinary radio-astronomical activity). In this way SETI observations can be performed for 24 h a day and 365 days a year at an extremely low cost. The Northern Cross is a 564 Â 640 m T-shaped UHF array having a collecting area of 30.000 m 2 and a 4 Â 4 arcmin beam cross section size. Due to the large collecting area, this array turns out particularly efﬁcient to look for very weak signals. The Northern Cross operates at 408 MHz (l = 73.5 cm) within a 2.7 MHz bandwidth. Part of this antenna has been recently reﬁtted with new technologies and architectures to prepare a UHF demon- strator for the Square Kilometre Array (SKA) [1]. Another section was technologically upgraded to implement a 800 m 2 superstation operating from 120 to 240 MHz, for the Low Frequency Array (LOFAR) project [2]. Even though the 1420 MHz frequency has been historically considered the most appropriate for SETI observations, new radio frequencies have been recently investigated by several groups for the search for extra- terrestrial life. Some examples are given by the SERENDIP Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/actaastro Acta Astronautica 0094-5765/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.actaastro.2010.03.005 Ã Corresponding author. E-mail address: s.montebugnoli@ira.inaf.it (S. Montebugnoli). Acta Astronautica 67 (2010) 1350–1355