RFI 2010 RFI Mitigation Workshop 29 31 March

RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope R. Ambrosini (IRA), P. Bolli (OAC), C. Bortolotti (IRA), F. Gaudiomonte (OAC), F. Messina (OAC), M. Roma (IRA) Osservatorio Astronomico di Cagliari Istituto di Radioastronomia Sezione di Medicina

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Agenda • The Italian radio telescopes; RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) • Update of the SRT’s construction; • The RFI monitoring systems of Medicina and SRT: • Fixed station; • Mobile station; • Recent activity of the RFI group: (i) faraday room, (ii) wind farm, and (iii) routine 2/26 measurements.

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Italian network RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Matera operato da ASI 3/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope SRT Technical Specifications • Fully steerable radio telescope for: Radio astronomy , Geodynamical studies, Deep Space Network, Single dish and VLBI • 0. 3 -100 GHz continuous frequency coverage • 64 m diameter primary mirror; 7. 9 m diameter secondary mirror RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) • Gregorian configuration with Shaped Surfaces • Active Surface: Primary mirror with 1116 actuators a) Compensate gravitational and thermal deformations b) Convert Shaped surface of the primary to a Parabolic surface for primary focus operation • Six focal positions (up to 20 receivers): Primary, Gregorian, Four Beam Wave Guide • Primary surface accuracy: 150 um RMS • Pointing accuracy (RMS): 2 ÷ 5 arcsec 4/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RA receivers for the first light RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Frequency band Note 305 – 410 MHz Primary, dual frequency 1. 3 – 1. 8 GHz Primary, dual frequency 5. 7 – 7. 7 GHz BWG, mono-feed 18 – 26 GHz Gregorian, multi-feed 5/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) RFI campaigns in Sardinia RFI Campaign Goals October 1992 RFI monitoring across South and Center Sardinia May 1996 RFI monitoring in Gerrei area November 1997 RFI monitoring in Gennargentu area October 2002 RFI characterization of the site chosen to host SRT June 2004 RFI measurement in the frequency bands of the first light receivers April 2007 Joined campaign with RFI mobile laboratory and fixed station installed at the site 6/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Features of SRT site The SRT site is located 35 Km North of Cagliari (700 m asl). RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Latitude: 39 d 29 m 50 s N Longitude: 9 d 14 m 40 s E 1. The site is well shielded by mountains sorrounding the radio telescope. 2. The area is far away from populated centers. 7/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope SRT update High level meeting between INAF and Communication Department of the Government are underway. RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Full support from National Administration. 8/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI monitoring system: goals RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) 1. …. monitoring the frequency bands allocated by ITU to RAS. If man-made signals interfere with the radio astronomical observations, an official claim must be reported to the National Administration asking for protection. 2. …. monitoring also the out-of-RAS bands used by astronomers to observe the sky. The RFI information can improve the design of microwave receivers, the strategies of scientific observation, and the mitigation 9/26 techniques.

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI monitoring system: scheme RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) A fixed station with antennas placed on a tower close to the radio telescope A mobile laboratory to move closer to the RFI transmitter (i) receive the interference, (ii) collect as many data as possible of the RFI, (iii) identify the content of the signal, (iv) and detect the exact position of the transmitter (triangulation). (i) good sensitivity, (ii) high compression point, (iii) wide frequency bands, (iv) automatically (24 h / day) and remotely controlled. 10/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Fixed RFI station: scheme 11/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Microwave front-end 12/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Fixed RFI station: comparison Features Medicina SRT (current version) Tower height 25 m 12 m >25 m Max frequency 2. 4 GHz 3 GHz 18 GHz Antennas 2 LPDA (80 – 500 MHz) 2 LPDA (500 – 1000 MHz ) 2 dual pol. Yagi (320 – 332 MHz) 2 dual pol. Yagi (400 – 416 MHz ) 2 dual pol. Yagi (606 – 612 MHz ) 1 reflector 1. 2 m pol. 45° (1. 3 – 2. 4 GHz ) 1 LPDA (0. 3 – 5 GHz) 1 LPDA (1. 2 – 2. 5 GHz) Rotor 1 axis for azimuth direction 2 axis for: azimuth direction and polarization Lenght & type of coaxial cable 35 m LCF ½” Cu 2 Y CELLFLEX (max 3 GHz) 55 m of FSJ 4 -50 B Andrew (max 10 GHz) Spectrum Analyzer AGILENT 8562 EC HP 8594 Receiver ICOM R 9000 Satellite monitoring 1 Az-El reflector 1. 5 m pol. 45° (1. 1 – 12 GHz) PSA 4446 E ICOM R 9500 Optical fiber link Not yet available 13/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI towers RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) SRT MEDICINA 14/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope SRT RFI laboratories RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) MEDICINA 15/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Fixed RFI station: performance M E D I C I N A S R T Band Frequency band Antenna gain Chain gain Noise figure 320 – 332 MHz 14 d. Bi 37 d. B 3 d. B (300 K) 400 – 416 MHz 15 d. Bi 36 d. B 3 d. B 606 – 612 MHz 16 d. Bi 32 d. B 3 d. B L 1. 29 – 1. 73 GHz 20 d. Bi 34 d. B 3. 5 d. B S 2. 20 – 2. 34 GHz 23 d. Bi 33 d. B 3. 5 d. B Satellite 1. 1 – 12 GHz (AZmonitor EL) 19 d. Bi 12 d. B @ 10 GHz Band Frequency band Antenna gain Chain gain Noise figure P 295 – 428. 5 MHz 6 d. Bi 28 d. B 10. 5 d. B (3000 K) L 1. 18 – 1. 80 GHz 12. 5 d. Bi 22. 3 d. B 10. 0 d. B S 2. 07 – 3. 39 GHz 5. 5 d. Bi 15. 7 d. B 13. 0 d. B P 16/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Mobile RFI stations RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) SRT MEDICINA 17/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) SRT Mobile RFI station 18/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Mobile RFI station: comparison Features Medicina SRT Van Fiat Ducato Mercedes Sprinter 315 CDI Maximum seats 3 2 Max frequency 18 GHz (Normal operation) 40 GHz Antennas 1 LPDA (0. 31 – 0. 62 GHz) 1 LPDA (0. 1 – 1. 3 GHz) 1 LPDA (1. 2 – 2. 4 MHz) 1 dual ridge horn (1 – 18 GHz) 1 horn (18 – 26. 5 GHz) 1 horn (26. 5 – 40 GHz) 1 LPDA (0. 3 – 0. 6 GHz) 1 LPDA (0. 1 – 1. 3 GHz) 1 dual ridge horn (1 – 18 GHz) 1 dual ridge horn (18 – 40 GHz) Telescope pole height 11 m Telescope movement Up/down servo Azimuth manual Polarization manual (standard 45°) Up/down servo Azimuth servo or manual Polarization servo Equipped SA SA HP 8562 A (up to 26. 5 GHz) PSA 4446 E (up to 44 GHz) Other characteristics Laboratory + storehouse; anti-shock rack; self powered (auxiliary batteries / AC 220 V); GPS 19/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Mobile RFI station: performance M E D I C I N A S R T Band Frequency band Antenna gain Chain gain Noise figure 300 – 434 MHz 5. 5 d. Bi 32 d. B 604 – 611 MHz 5. 5 d. Bi 29 d. B 9. 5 d. B L/S 1. 22 – 2. 45 GHz 4 or 9 d. Bi 32 d. B 4. 5 d. B S 2. 45 – 4 GHz 4. 5 d. Bi 26 d. B 5 d. B C 4 – 8 GHz 5 d. Bi 28 d. B 4. 5 d. B X 8 – 12 GHz 6 d. Bi 49 d. B 5 d. B Ku 12 – 18 GHz 8 d. Bi 37 d. B 8. 5 d. B K 18 - 26. 5 GHz 21 d. Bi 56 d. B 3. 1 d. B Ka 26. 5 – 40 GHz 21 d. Bi 50. 5 d. B 4 d. B Band Frequency band Antenna gain Chain gain Noise figure P 290 – 428 MHz 9 d. Bi 36. 2 d. B 3. 8 d. B L 1. 17 – 1. 84 GHz 7 d. Bi 29. 8 d. B 4 d. B S 1. 99 – 3. 37 GHz 7. 8 d. Bi 25 d. B 5. 3 d. B S/C 2. 98 – 5. 81 GHz 12 d. Bi 25 d. B 5. 5 d. B C/X 5. 22 – 9. 25 GHz 11. 5 d. Bi TBD X / Ku 7. 76 – 18 GHz 12. 5 d. Bi TBD K / Ka 18 – 40 GHz TBD TBD P 20/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Faraday room at SRT site RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) RFI measurements were conducted to evaluate the emission of a super-computing facility (80 nodes with dual CPU dual core each) to be placed at SRT. Goal of the measurement was to evaluate if the auto-interference are compatible with Rec. 769. If not, to identify the shielding level of a Faraday room to be installed at SRT station. 21/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) Faraday room at SRT site The figures we got (especially at frequencies lower than 1 GHz) exceed by about 60 d. B, the detrimental values suggested by ITU-R RA. 769 -2 as the ones representative for continuum and spectral line radio astronomy observations. 22/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) RFI campaign at a wind farm Wind farm Monte Guzzini (CA) Number of turbins 26 Electrical power (maximum) 22 Mwatt (850 Kwatt each) Modell of turbine VESTAS V-52 Dimension of each turbine Height of the mast 55 m, 3 blades with radius 26 m Type of measurement Primary emission (no reflection contribution) 23/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) RFI campaign at a wind farm -85 d. BW (0 d. Bi) Very strong wide band impulsive signal mainly in P (350 MHz) and L (1. 5 GHz) bands associated electrical discharges in the power station of the wind farm. 24/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Routine RFI measurements RFI 2010 Power - RFI[d. Bm] Mitigation Workshop with respect to 0 d. Bi (RBW=100 KHz) 29 - 31 March, 2010, Groningen (NL) Routine RFI measurements are conducted every week to monitor the band of interest for the first light of SRT. External CW at 426 MHz The P frequency band of the dual frequency receiver was reduced from 305 -425 MHz to 305 -410 MHz. Two identical HTS microwave band-pass filters are underway in collaboration with Prof. Lancaster and Dr. Huang (Univ. of Birmingham) Frequency [MHz] 25/26

P. Bolli, The RFI monitoring systems for the Medicina and the Sardinia Radio Telescope Conclusions • SRT is very close to its inauguration; RFI 2010 - RFI Mitigation Workshop 29 - 31 March, 2010, Groningen (NL) • A team of local technicians has been trained to take care of the RFI problems; • SRT is in progress to be equipped with state-of-the-art RF instrumentation for monitoring the RFI, following the thirty-year experience gathered at Medicina; • The RFI activity consists both: (i) in routine measurements at the site, and (ii) in ad hoc campaign addressed to specific questions. 26/26