Project Cyclops, A Design... - Department of Earth and Planetary ...

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APPENDIX A - Astronomical Data ............................... 173 B - Supercivilizations and Cultural Longevity ..................... 177 C - Optimum Detection and Filtering ......................... 183 D - Square Law Detecticn Theory .......................... 187 E - Response ofa Caussian Filter to a Swept Sinusoid .................. 197 F - Base Structures ................................ 199 G - Back-Up Structures ............................... 205 H - Polarization Considerations ........................... 207 I - Cassegrainian Geometry ............................. 209 J - Phasing of the Local Oscillator .......................... 211 K - Effect of DisFersion in Caaxials ......................... 213 L - Tunnel and Cable Lengths ............................ 215 M - Phasing and Time Delay ............................. 221 N - System Calibration ............................... 227 O - The Optical Spectrum Analyzer ......................... 229 P - lumped Corstant Delay Lines .......................... 233 Q - Curves of Detection Slatistics .......................... 237 R - Radio Visibility of Normal Stars with Cyclops ................... 241
1. INTRODUCTION Each summer for the last five years the National Aeronautics and Space Administration (NASA) has funded eight faculty fellowship programs in cooperation with the American Society for Engineering Education (ASEE). The selection of four sites is governed by the proximity of a NASA facility to a university. Two programs are conducted at each site-one research oriented and the other engineering-design oriented. Project Cyclops is the 1971 NASA-ASEE Summer faculty Fellowship Program in Engineering Systems Design conducted jointly by Stanford University and Ames Research Center. A major objective of these programs is to provide an educational experience for young faculty members of American universities. The Engineering Systems Design programs, for example, usually involve several disciplines, each represented by individuals involved in the program. The interaction of the disciplines, as well as the tradeoffs available for optimizing the overall system, becomes apparent. Each specialist inevitably learns something about the other fields involved in the total system design. While the overall objectives of the summer programs are educational, it is important that any system studied have a clearly stated objective or set of objectives. The primary objective of Project Cyclops was: To assess what would be required in hardware, manpower, time and fitnding to mount a realistic effort, using present (or near-term future) state-of-the-art techniques, aimed at detecting the existence of extraterrestrial (extrasolar system) intelligent life. By a "realistic effort" is meant one having a high probability of success, based on our best estimates of all the factors involved. Because our present knowledge does not allow accurate estimates of the density of intelligent and especially of communicative life in the universe and therefore of the volume of space that must be searched, the Cyclops system design must take this uncertainty as to the magnitude of the problem into account at the outset. This suggests starting with the minimum system that would probably be needed and increasing its size till success is achieved or until a new and superior technique is discovered. Cyclops is therefore not a fixed static system but a flexible expandable one. This report presents the conclusions reached in this summer study including a possible system design (with some alternatives) and some cost estimates. However, it should be emphasized that, because of time and manpower limitations, this study represents only about two to three man-years of effort. Before cost estimates can be made that are accurate enough to permit a go-no-go decision, at least ten times this effort will be needed. And before a final detailed design can be specified at least a thousand times the present Cyclops effort will have been expanded. Thus the present report must be taken as only a very preliminary and rough set of estimates. Although the Cyclops system as here described would have certain important applications in both radio astronomy and communication with deep space probes both the extremely preliminary nature of this study and tile great uncertainty as to whether a system of this type will be built in the reasonably near future force us to emphasize that presently contemplated expenditures in radio astronomy, radar mapping and deep space communication facilities should be evaluated without regard to the content of this report. It would be extremely unfortunate if funding for any worthwhile projects in these fields were to be deferred or reduced because of a mistaken impression regarding the imminence of a Cyclops-like system. Rather we would hope that the fact that many people are willing to consider the magnitude of expenditures involved in Cyclops might serve to emphasize how greatly under financed radio astronomy, for example, is at the present time.
Page 1 and 2: (NASA-CR- 11_5) PROJECT CYCLOPS: A
Page 3 and 4: CR 114445 Available to the public A
Page 6 and 7: At this very minute, with almost ab
Page 8 and 9: ACKNOWLEDGMENTS The Cyclops study w
Page 10 and 11: COMMUNICATION BY ELECTROMAGNETIC WA
Page 14 and 15: t _ 2
Page 16 and 17: of the living beings evolved by the
Page 18 and 19: Figure2-1. M3I,the great galaxy in
Page 20 and 21: self.Thus,wecaninterpretFigure2-2as
Page 22 and 23: magnitude (low brightness) end, the
Page 24 and 25: Red Giant. The transition from main
Page 26 and 27: tion, as the central part of the cl
Page 28 and 29: TABLE 2-4 SELECTED NEARBY STARS WIT
Page 30 and 31: tideraisingforcesasr--_ where ,v =
Page 32 and 33: 3. Is it possible that living syste
Page 34 and 35: lawsof natural selection, more like
Page 36 and 37: starsthroughout the Galaxyhave also
Page 38 and 39: if the longevity of that life is ty
Page 40 and 41: The imaginative reader will have no
Page 42 and 43: Lookingfar ahead,supposewe aresucce
Page 44 and 45: usuallyterritorial expansion by the
Page 46 and 47: IOO IO 1 [ [ J [ J I J i [ i I i I
Page 48 and 49: order with what Morrison has descri
Page 50 and 51: The quantity gtPt is often called t
Page 52 and 53: which might result from synchronous
Page 54 and 55: 1. Wewillnothavenough resolving pow
Page 56 and 57: normalwith the meanat o x/--2. When
Page 58 and 59: Chapter11 in analyzingthe dataproce
Page 60 and 61: Therangelimitisthenfoundbyequating_
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TABLE 5-3 PARAMETER Wavelength Tran
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angeanddirectlyasthesquareof antenn
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"_ i i i i i p = STELLAR DENSITY AT
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I-- g u. O >- I--- .d tit (]O 0 0.
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andwidth that will still give near
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acquisitionphasefor otherraces.Supp
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1. They would transmit continuously
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and ¢-Ceti. No signals were detect
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vz .i g)mo PAGE NOr Ir[[,MZ 7. THE
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The price of incomplete sky coverag
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modest size.A largedatabaseontapeor
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THEAUXILIARYOPTICALSYSTEM Althoughn
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edetectedat 20,000light-years byCyc
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feeds must correct for spherical ab
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side of the dish and shade on the o
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TABLE 8-1 UNADJUSTED UNIT COST DATA
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7. Using huge specially designed ji
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9. THE RECEIVER SYSTEM The receiver
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whereP is the radiated power. Divid
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SHADOWED AREA SHADOWED AREA // // /
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Corrugatedhornssupportingbalancedhy
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o 50 ----- - _ T i 20 _,o 5 ,,,5 09
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TABLk ?- I A COMPARISON OF VARIOUS
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CENTRAL POINT STATION LSB LINE FREQ
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A02 .... + No (25) (i C 1 where No
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COAXIAL LINE DIRECTIONALCOUPLER FRE
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DeJager, J.T.:IEEETrans.onMicrowave
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pR_ING PA6E BLANK HOT FILMF_ 10. TR
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o-------------o_ _ o o o o ing of t
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addedto theother IF channel. The tw
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INPUT MHZ _PF 500 MHZ i : 575 T1 92
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azimuth _) has a delay (2a/c)sin 0
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stripline. For 2 _< k _< 6, appropr
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mation are common to all antennas i
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A cable pair costs about 20 cents/m
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11. SIGNAL PROCESSING The Cyclops s
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1.0 T t t I I r .9 -8 asynchronousl
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collimated coherent light. A simple
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power of the film and associated op
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samples simultaneously onto the sam
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outputs is assumed. COMPOSITE SIGNA
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SPECTRUM I n LINES M n LINES U SPEC
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signal andyet have a tolerable fals
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i --_- i i i i large values of n. T
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plottedin Figure11-15for various va
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All the1Fsignalswillarrivein phasei
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x:(1 +x) x 2 - _ -- (53) If we wish
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3's = unitcostof signal planelectro
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where0ma x is the maximum value of
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Roughestimates of the costs of buil
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12. CYCLOPS AS A BEACON Although th
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13. SEARCH STRATEGY The high direct
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distantgalaxies (oraninertialrefere
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wouldfollowtheuppermost linein Figu
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persquaredegreeof fieldwouldberequi
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starsfrom/'18 to G5 could support a
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14. CYCLOPS AS A RESEARCH TOOL Thro
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Only a few such galaxies have been
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15. CONCLUSIONS AND RECOMMENDATIONS
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perhapsdecadesand possiblycenturies
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APPENDIX A ASTRONOMICAL DATA DISTAN
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PLANETARY Planet ORBITS Semimajor S
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APPENDIX B SUPERCIVILIZATIONS AND C
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ABIOLOGICAL CIVILIZATIONS Many writ
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182
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tqOT APPENDIX C OPTIMUM DETECTION A
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to rmsnoise.Wenotethatthematchedfil
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APPENDIX D SQUARE LAW DETECTION THE
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If the output filter is very wide c
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if B/2 > T we can start instead wit
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Let us now introduce the normalized
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where h-- = expectation count of si
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APPENDIXE RESPONSE OF A GAUSSIAN FI
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APPENDIXF BASE STRUCTURES AZ-EL BAS
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ack,it shouldnotbenecessary to prov
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204
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206 i
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PAGE BLANK NOT APPENDIX H POLARIZAT
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APPENDIX I CASSEGRAINIAN GEOMETRY C
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APPENDIXJ PHASINGOFTHE LOCALOSCILLA
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APPENDIXK EFFECTOF DISPERSION IN CO
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APPENDIX L TUNNEL AND CABLE LENGTHS
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where r = "Ym/'rs- If we let o-_--o
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L-4 we see that the length of IF ca
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APPENDIX M PHASING AND TIME DELAY A
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andobtain V = 2 (Ps [! + _(Ar)] +Pn
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L" D 226
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APPENDIX N SYSTEM CALIBRATION The p
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APPENDIXO THE OPTICAL SPECTRUM ANAL
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232
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APPENDIX P LUMPED CONSTANT DELAY LI
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Thevalueofthefinalcoilonthelineis =
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APPENDIXQ CURVES OF DETECTION STATI
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I I I I LE :E oo
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APPENDIX R RADIO VISIBILITY OF NORM
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io 3 - l rlrllll I I I ]l+,ll_ I _f
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