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SETI on the SKA. Dan Werthimer University of California, Berkeley. http://seti.berkeley.edu/. SETI history SETI today SETI future (SKA) Signal processing. NOT FUNDED. NOT FUNDED. NOT FUNDED. Porno in space: FUNDED!. First Radio SETI. Nikola Tesla (1899)
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SETI on the SKA Dan Werthimer University of California, Berkeley http://seti.berkeley.edu/
SETI history • SETI today • SETI future (SKA) • Signal processing
Porno in space: FUNDED!
First Radio SETI • Nikola Tesla (1899) • Announces “coherent signals from Mars” • Guglielmo Marconi (1920) • Strange signals from ET • Frank Drake (1960) • Project Ozma • one channel, 1420-1420.4 MHz
Traditional SETI dogma: ultra narrow band sine waves barycentric, beacons, FGK stars 21 cm Future dogma: many bandwidths, frequencies, drifting signals, pulses, M stars, galaxies
It’s naïve to think we know how best to search today, given our history of changing SETI fashion. • Multiple strategy is best (IR, Vis, Radio, pulse, continuous, targetted sky survey…) • Half of astronomy discoveries are serendipitous • Examine glitches in data • Data Mining Experiments
OPTICAL SETI 1961 Charlie Townes Paper largely ingored until 1999 1971 Cyclops report calculates radio >> optical Today’s lasers can communicate across galaxy
Optical SETI experiments • Lick Observatory (Lick, Seti Institute, Berkeley) • Harvard (targetted sky survey) • Princeton • Berkeley
10-meter Keck Telescope Survey: 650 F8 – M5 V, IV Hipparcos V < 8.5 B-V > 0.55 (F8V) Sep > 2 arcsec Age > 2 Gyr
Keck Optical SETI – Data Mining • Geoff Marcy, Amy Reines • 650 stars (planet data) • Echelle Spectrometer • Can detect 10KW narrow band signal (10 KW laser on 10 meter telescope)
SETI GOAL: SkyCoverage * FreqCoverage * Sensitivity^-3/2 * Nsignaltypes solid angle vs number of nearby FGK stars? FreqCoverage vs Noctaves? Pulses vs sinewaves vs drifting vs broadband…? FreqCoverage, SkyCoverage, signal types: other telescopes sensitivity: SKA
Radio SETI Targetted Search Strategy Project Phoenix - Seti Institute Sky Survey Strategy Serendip, SETI@home - UC Berkeley Southern Serendip - Australia Meta II - Argentina Seti Italia - Bologna
University of California, Berkeley SETI Program • Graduate Students Chen Chang, Karl Chen, Paul Demorest, Nia Imara, P. Monat, A. Parsons • Undergraduate Students Noaa Avital, Brian Boshes, Henry Chen, Charlie Conroy, Chris Day, Daniel Hsu, Wonsop Sim, Ryo Takahashi • Astronomers and Computer Scientists David Anderson, Bob Bankay, Jeff Cobb, Court Cannick, Eric Korpela, Matt Lebofsky, Jeff Mock, Dan Werthimer, Rom Walton • Administrative Staff - None
SERENDIP IV Photos Courtesy NAIC Arecibo Observatory, a facility of the NSF • 168M channels • 100 MHz Band centered on 1420 MHz • Carriage House 1 line feed • Operating since 1997
Why SETI@home? • Coherent Doppler drift correction • Narrower Channel Width->Higher Sensitivity • Variable bandwidth/time resolution • Search for multiple signal types • Gaussian beam fitting • Search for repeating pulses Problem: Requires TFLOP/s processing power. Solution: Distributed Computing
SETI@home Statistics TOTAL RATE
SETI@home in Canada • 255,426 participants (0.8% of population) • 112,000 years of computer time • 72 million work units
Web site: 2 million hits/day 200,000 visitors/day(stats & games popular; science less popular)100,000 children, families(including congress members and their kids)> 7,000 schools
Desired SKA Parameters • Wide bandwidth • 1 M beams • fat beams • short dwell times (~ 100 seconds)
BOINC • Berkeley Open Infrastructure for Network Computing • General-purpose distributed computing framework. • Open source. • Will make distributed computing accessible to those who need it. (Starting from scratch is hard!)
BOINC Projects • SETI@home (Berkeley)) • Astropulse (Berkeley) • ClimateModeling@home (Oxford) • Einstein@home (Caltech) • Folding@home (Stanford) • ParticlePhysics@home (CERN) • Stardust@home (U. Wa, Berkeley)
AstroPulse • Sky survey • Covers decs 0 to 30 • ~3 years of data recorded so far. • Good time resolution • Sensitive to 0.4 µs radio pulses at 21 cm • DM range • -1000 to +1000 pc/cm3 • Sensitivity • 10-18 W/m2 peak (Coherent de-dispersion)
Piggyback ALFA Sky Survey • Improved sensitivity • Tsys, integration time • Uniform sky sampling • galactic plane concentration • Multibeam RFI rejection • Larger Bandwidth
Search for Optical/Radio Signals from Dyson Sphere Candidates| Charlie Conroy Looked for IR excess from >500 stars All stars had age > 1 Gigayear 33 stars found with 12m excess Searched for anomalous radio detection using SETI@home and SERENDIP IV databases Searched for optical pulse emission using OSETI experiment Thus far, none of the 33 sources have shown anomalous optical or radio emission Color excess using 2MASS K band data and 12, 25, 60, & 100 micron IRAS data. An excess at K-[12] is clearly visible and disappears by K-[25]. Dotted lines are Gaussian fits to the distributions. The 33 IR excess candidates have K-[12] > 3 above the mean.
‘Prelude’ Precedes SonATAIn Fall 2004For Use On The ATA-32 3 beams with 30 MHz each – PCs with accelerator cards
Moore’s Law in FPGA world 100X More efficient than micro-processors! 3X improvement per year!