The SETI@home, The SETI@home, SERENDIP, SEVENDIP, SERENDIP, SEVENDIP, Astropulse, and SPOCK Astropulse, and SPOCK

SETI ProgramsSETI Programs

‘‘Dan Werthimer, Dave Anderson, Jeff Cobb, Dan Werthimer, Dave Anderson, Jeff Cobb, Paul Demorest, Eric Korpela, Cecile Kim, Geoff MarcyPaul Demorest, Eric Korpela, Cecile Kim, Geoff Marcy

University of California, BerkeleyUniversity of California, Berkeley

http://seti.berkeley.edu/

NOT FUNDED

NOT FUNDED

NOT FUNDED

Porno in space:

FUNDED!

Drake EquationDrake Equation

• N=R fN=R fss f fpp n nee f fll f fii f fcc L L

• N = number of communicating N = number of communicating civilizations in our galaxycivilizations in our galaxy

Planet DetectionPlanet Detection

First Radio SETIFirst Radio SETI• Nikola Tesla (1899)Nikola Tesla (1899)

– Announces “coherent signals from Mars”Announces “coherent signals from Mars”

• Guglielmo Marconi (1920)Guglielmo Marconi (1920)– Strange signals from ETStrange signals from ET

• Frank Drake (1960)Frank Drake (1960)– Project Ozma Project Ozma

– one channel, 1420-1420.4 MHzone channel, 1420-1420.4 MHz

Signal Types1. Artifact (radio, radar, ~TV, ????)

2. Deliberate (easy to decode, pictures, language lessons)

First civilization we contact is likely to be a billion years ahead of us.

Targeted Search Strategy: Targeted Search Strategy:

Project Phoenix - Seti InstituteProject Phoenix - Seti Institute

Sky Survey Strategy:Sky Survey Strategy:

Serendip, SETI@home - UC BerkeleySerendip, SETI@home - UC Berkeley

Beta - HarvardBeta - Harvard

Southern Serendip - AustraliaSouthern Serendip - Australia

Meta II - ArgentinaMeta II - Argentina

Seti Italia - Medicina Obser.Seti Italia - Medicina Obser.

Quick History of Berkeley Quick History of Berkeley SETISETI

• Radio SETIRadio SETI– SERENDIPSERENDIP

SSearch for earch for EExtraterrestrial xtraterrestrial RRadio adio EEmissions missions from from NNearby earby DDeveloped eveloped IIntelligent ntelligent PPopulationsopulations

• SERENDIP I-III (1979-SERENDIP I-III (1979-1997)1997)

• SERENDIP IV (1997-)SERENDIP IV (1997-)

• SERENDIP V (2004-)SERENDIP V (2004-)

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+10

1979 1984 1989 1994 1999 2004

Channels Bandwidth [kHz]

Resolution [/kHz] Beams

Sensitivity ([-25] W/m2) Drake FOM [Hz*Sr*m3/W1.5]

The Berkeley Radio SETI Family The Berkeley Radio SETI Family TreeTree

SERENDIPSERENDIP

SERENDIP IISERENDIP II

SERENDIP IIISERENDIP III

SERENDIP IVSERENDIP IV

SERENDIP VSERENDIP V

SETI@homeSETI@home

Data RecorderData Recorder

SETI@home IISETI@home II

Data RecorderData Recorder

SETI@homeSETI@home

ClientsClients

SETI@home IISETI@home II

ClientsClients

SETHSETHII@Berkeley@Berkeley

HI SurveyHI Survey

AstroPulseAstroPulse

Pulse SurveyPulse Survey

SETI ItaliaSETI Italia

SouthernSouthern

SERENDIPSERENDIP

OSUOSU

SETI Programs at the SETI Programs at the University of University of CaliforniaCalifornia

NAME TIME SCALE SEARCH TYPE

SERENDIP 1 second Radio sky survey

SETI@home ms to second Radio sky survey

ASTROPULSE us to ms Radio sky survey

SEVENDIP ns Visible targetted

SPOCK 1000 seconds Visible targetted

SERENDIP IVSERENDIP IV

• 168M channels168M channels

• 100 MHz Band centered on 1420 100 MHz Band centered on 1420 MHzMHz

• Carriage House 1 line feedCarriage House 1 line feed

• Operating since 1997Operating since 1997

Photos Courtesy NAIC Arecibo Observatory, a facility of the NSFPhotos Courtesy NAIC Arecibo Observatory, a facility of the NSF

Why SETI@home?Why SETI@home?

• Coherent Doppler drift correctionCoherent Doppler drift correction– Narrower Channel Width->Higher SensitivityNarrower Channel Width->Higher Sensitivity

• Variable bandwidth/time resolutionVariable bandwidth/time resolution

• Search for multiple signal typesSearch for multiple signal types– Gaussian beam fittingGaussian beam fitting

– Search for repeating pulsesSearch for repeating pulses

Problem: Requires TFLOP/s processing power.

Solution: Distributed Computing

The SETI@home ClientThe SETI@home Client

4,324,355 participants(in 226 countries)

2,000 per day

1,168,254 yearscomputer time

1,200 years per day

1021 floating pointoperations

55 Tera-flops

SETI@home Statistics

TOTAL RATE

Structure of SETI@homeStructure of SETI@home

Tapes fromTapes fromAreciboArecibo

OnlineOnlineScienceScienceDatabaseDatabase

3.8 Million Volunteers3.8 Million Volunteers

The InternetThe Internet

Work Unit StorageWork Unit StorageData splittersData splitters

VolunteerVolunteerStatisticsStatisticsDatabaseDatabase

MasterMasterScienceScienceDatabaseDatabase

Result VerificationResult VerificationCandidate IdentificationCandidate Identification

Web ServerWeb Server

Data ServerData Server

The Input and OutputThe Input and Output• 1 Work-Unit=9.8 kHz x 21 Work-Unit=9.8 kHz x 22020 samples (107 samples (107

sec.)sec.)– 256 Workunits across 2.5 MHz band centered 256 Workunits across 2.5 MHz band centered

on 1420.0 MHz.on 1420.0 MHz.

– Workunits overlap in time by ~25 sec.Workunits overlap in time by ~25 sec.

– Each workunit sent to multiple computers for Each workunit sent to multiple computers for result verificationresult verification

– Typically 4 TFLOP/workunit.Typically 4 TFLOP/workunit.

• Output=Typically ~5 potential signals.Output=Typically ~5 potential signals.

SpikesSpikes

• Power distribution Power distribution in the Fourier in the Fourier transformed data is transformed data is exponential if no exponential if no RFI.RFI.

• SPIKE: Any bin in SPIKE: Any bin in the spectrum the spectrum above 22X the above 22X the mean power mean power (7.8x10(7.8x10-25-25 W/m W/m22))

GaussiansGaussians

• Weighted Weighted 2 2 fit to fit to beam profile (vs beam profile (vs time)time)..

• Gaussian must Gaussian must exceed a power exceed a power and and 2 2 thresholdthreshold

• Score inversely Score inversely proportional to proportional to probability of probability of arising due to noisearising due to noise

• Sensitivity 8.4x10Sensitivity 8.4x10-25-25 W/mW/m22

TripletsTriplets

• Three evenly Three evenly spaced spikes spaced spikes above 7.75X the above 7.75X the mean power. mean power. (5.3X10(5.3X10-25-25 W/m W/m22))

PulsesPulses

• Modified Fast Modified Fast folding algorithm folding algorithm w/ dynamic w/ dynamic thresholdthreshold

• Logarithmically Logarithmically spaced periods spaced periods from 3ms to 35sfrom 3ms to 35s

• Sensitivity as low Sensitivity as low as 10as 10-26-26 J/m J/m22

Candidate IdentificationCandidate Identification• Candidate:Candidate: A signal or group of signals A signal or group of signals

– Within a positional window (~1 beamwidth typ.)Within a positional window (~1 beamwidth typ.)

– Within a frequency window (variable)Within a frequency window (variable)

– Above a score or power threshold (variable)Above a score or power threshold (variable)

– With time separation » typical transient RFI With time separation » typical transient RFI timescaletimescale

• Score:Score: – Relative ranking of a candidate’s probability of Relative ranking of a candidate’s probability of

arising due to random noise.arising due to random noise.

– Should be independent of signal typeShould be independent of signal type

– Can also include probability of coincidence /w Can also include probability of coincidence /w celestial objectscelestial objects

Gaussian CandidatesGaussian Candidates

AstroPulseAstroPulse• Sky surveySky survey

– Covers decs 0 to 30Covers decs 0 to 30

– ~3 years of data recorded so far.~3 years of data recorded so far.

• Good time resolutionGood time resolution– Sensitive to 0.4 µs radio pulses at 21 cmSensitive to 0.4 µs radio pulses at 21 cm

• DM rangeDM range– -100 to +100 pc/cm-100 to +100 pc/cm33

• SensitivitySensitivity– 1010-18-18 W/m W/m22 peak (Coherent de-dispersion) peak (Coherent de-dispersion)

Pulsed vs. CWPulsed vs. CW

Concentrating power into short bursts can be more efficient than a “constantly on” transmitter.

Pulsed signals can be easier to see above background noise.

DispersionDispersion

… eventually becoming very weak.

However, we can correct for dispersion ...

AstroPulseAstroPulse• Only ~1.5 searches for single Only ~1.5 searches for single

pulses on µs timescale before pulses on µs timescale before (O’Sullivan, Phinney) (O’Sullivan, Phinney)

• Pulsar searches: ms time scales, Pulsar searches: ms time scales, foldedfolded

• SETI@home: 0.8 ms single pulses.SETI@home: 0.8 ms single pulses.

• With interesting astrophysics as With interesting astrophysics as well as SETI applications.well as SETI applications.– Evaporating primordial black holes? Evaporating primordial black holes?

– Pulsars, Other astrophysical Pulsars, Other astrophysical exotica?exotica?

ComputationComputation

… but it takes a lot of CPU time!

To search DMs up to 100 pc/cm3 in real time, we need about 500 GigaFLOPs.

(This would take ~1000 years of your PC working full time)

Conclusion: We need more computers!

BOINCBOINC

• Berkeley Open Berkeley Open Infrastructure for Network Infrastructure for Network ComputingComputing

– General-purpose distributed General-purpose distributed computing framework.computing framework.

– Open source.Open source.

– Will make distributed Will make distributed computing accessible to computing accessible to those who need it. (Starting those who need it. (Starting from scratch is hard!)from scratch is hard!)

AstroPulse/BOINCAstroPulse/BOINC• AstroPulse will be the first to use AstroPulse will be the first to use

BOINC.BOINC.

• It is a good “beta-test” application:It is a good “beta-test” application:

– Simple data analysis/reduction.Simple data analysis/reduction.

– ““Only” needs a few thousand computers. Only” needs a few thousand computers.

– Other projects which plan to use BOINC:Other projects which plan to use BOINC:

– SETI@home IISETI@home II

– Global climate modeling/prediction Global climate modeling/prediction (Oxford)(Oxford)

AstroPulse TestingAstroPulse Testing

Sample batch of data run through shows expected noise characteristics, and little else …

… so (hopefully) little RFI contamination for this type of signal.

HI Column Density

OPTICAL SETIOPTICAL SETI• OPTICAL PULSE SEARCHOPTICAL PULSE SEARCH

– Pulsed laser power output continues to Pulsed laser power output continues to grow.grow.

– Petawatt pulses achieved at Livermore Petawatt pulses achieved at Livermore Labs. (Mjoule in 1nS)Labs. (Mjoule in 1nS)

– can detect at earth technology at 1Kpccan detect at earth technology at 1Kpc

– little background noise, even from bright little background noise, even from bright stars in whole visible bandstars in whole visible band

OSETI DetectorOSETI Detector• 3-Photomultiplier fast 3-Photomultiplier fast

coincidence detectorcoincidence detector– Sensitive to 1ns pulsesSensitive to 1ns pulses

• Low backgroundLow background– False alarm rate: 1 per 300 False alarm rate: 1 per 300

hours (10hours (10-6-6 Hz) Hz)

– Double false alarm rate: 1 Double false alarm rate: 1 per 600 years!per 600 years!

• Good sensitivityGood sensitivity– 1010-8-8 W/m W/m22 peak peak

– 1010-19-19 W/m W/m22 average average

Optical SETIOptical SETI• Uses Leuschner Uses Leuschner

Observatory (UCB)Observatory (UCB)– Automated 0.8m Automated 0.8m

telescopetelescope

• Targeted SearchTargeted Search– Nearby F,G,K,M starsNearby F,G,K,M stars

– ~2,000 stars observed ~2,000 stars observed so farso far

– Soon to include galaxiesSoon to include galaxies

Amy Reines and Geoff Amy Reines and Geoff MarcyMarcy

10-meter Keck Telescope10-meter Keck Telescope

Survey: 650 F8 – M5 V, IVSurvey: 650 F8 – M5 V, IV

Hipparcos V < 8.5B-V > 0.55 (F8V)Sep > 2 arcsecAge > 2 Gyr

Doppler InstrumentsDoppler Instruments

• Echelle Echelle SpectrometerSpectrometer

• Resolution: 60,000Resolution: 60,000

• Iodine Abs. Cell.Iodine Abs. Cell.

– Superimpose ISuperimpose I22 lines lines

– Wavelength Calib.Wavelength Calib.

Piggyback ALFA Sky SurveyPiggyback ALFA Sky Survey• SETI InstrumentsSETI Instruments

– Dedicated spectrometer (SERENDIP V)Dedicated spectrometer (SERENDIP V)• 300 MHz bandwidth, 2 pols, 7 beams300 MHz bandwidth, 2 pols, 7 beams

• 5 * 105 * 1099 channels, 0.8 Hz resolution channels, 0.8 Hz resolution

– SETI@home II data recorderSETI@home II data recorder• 10 MHz, 1 pol, 7 beams10 MHz, 1 pol, 7 beams

• Steps across 300 MHz bandSteps across 300 MHz band

Piggyback ALFA Sky SurveyPiggyback ALFA Sky Survey• Improved sensitivity Improved sensitivity

– Tsys, integration timeTsys, integration time

• Uniform sky sampling Uniform sky sampling – galactic plane concentrationgalactic plane concentration

• Multibeam RFI rejectionMultibeam RFI rejection

• Larger BandwidthLarger Bandwidth

Our Generous SponsorsOur Generous Sponsors• The Planetary SocietyThe Planetary Society

• The University of CaliforniaThe University of California

• Sun MicrosystemsSun Microsystems

• Friends of SETI@homeFriends of SETI@home

• Network ApplianceNetwork Appliance

• FujifilmFujifilm

• IBMIBM

• QuantumQuantum

• HP HP

• XilinxXilinx

• The SETI InstituteThe SETI Institute

• InformixInformix

• EDTEDT

• NetscreenNetscreen

• IntelIntel

• O’Reilly & AssociatesO’Reilly & Associates

• SpaceSoundsSpaceSounds

• Dillon EngineeringDillon Engineering

• NAIC, Arecibo ObservatoryNAIC, Arecibo Observatory

• ~4 million volunteers ~4 million volunteers

Maybe, someday, the U.S. Government

•SETI HAIKU

Seti.berkeley.edu