NASA-CR-194177 /_- 7"-__F/,'_"t C/7, E) Report To The NATIONAL AERONAUTICS AND SPACE ADMINISTRATION - AMES RESEARCH CENTER - SEMIANNUAL STATUS REPORT #5 for GRANT NAG 2-700 SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE/ HIGH RESOLUTION MICROWAVE SURVEY TEAM MEMBER Paul G. Steffes, Principal Investigator Report Period: March I, 1993 through August 31, 1993 Submitted by Professor Paul G. Steffes School of Electrical Engineering Georgia Institute of Technology Atlanta, Georgia 30332-0250 (404 894-3128) (NASA-CR-194177) SEARCH FOR N94-13086 EXTRATERRESTRIAL INTELLIGENCE/HIGH RESOLUTION MICROWAVE SURVEY TEAM MEMBER Semiannuel Status Report No. Unclas 5, 1 Mar. - 31 Aug. 1993 (Georgia Inst. of Tech.) 61 p G3155 0185928 TABLE OF CONTENTS INTRODUCTION AND SUMMARY Io II. DEVELOPMENT OF A DATA BASE OF SPACEBORNE TRANSMITTERS III. OBSERVATIONAL STUDIES IV. CONCLUSION V. REFERENCES Vl. APPENDICES 1. INTRODUCTION AND SUNiARY This semiannual status report describes activities conducted by the Principal Investigator during the first half of this third year of the NASA High Resolution Microwave Survey (HRMS) Investigator Working Group (IWG). As a (HRMS) Team Member with primary interest in the Sky Survey activity, this investigator attended IWG meetings at NASA/Ames and U.C. - Santa Cruz in April and August 1992, and has traveled independently to NRAO/KittPeak, Arizona (April Igg3) and Woodbury, Georgia (July 1993). During the July 1993 visit to the Georgia Tech Research Corporation/Woodbury Research Facility, an experiment was conducted to study the effects of interference from C-band (3.7 - 4.2 GHz) geostationary spacecraft on the Sky Survey operation in that band. At the first IWG meeting in April of this year, results of a SETI observation conducted at the 203 GHz positronium hyperfine resonance using the NRAO facility at Kitt Peak, AZ, were presented, as well as updates on the development of the spaceborne RFI data bases developed for the project. (See Appendix II and Section II.) At the second meeting, results of the study of interference from C-band geostationary spacecraft were presented (see Appendix Ill). Likewise, a presentation was made at the accompanying 1993 Bioastronomy Symposium describing the SETI observation at the positronium hyperfine resonance (Steffes and DeBoer, ]gg3a--see Appendix I). This work has also been submitted to Icarus (see Appendix II, Steffes and DeBoer, Igg3b) after being approved by the IWG Publications Coordinator. In the remainder of this grant year (through February 28, 1994), we expect to continue the development of the spaceborne RFI data base. Specifically, we intend to release a new revision including an expanded section containing the most up-to-date information on low earth orbiting satellites. Likewise, we will ] assisl in planning the Summer 1994 SKy Survey deployment at the Owens Valley Radio Observatory, so as to assure that portions of the L-Band spectrum which will soon be occupied by the mobile satellite service will be surveyed before they are occupied by spaceborne transmitters. II. DEVELOPMENT OF DATA BASE OF SPACEBORNETRANSMITTERS We have formed a data base of all non-classified satellites, giving transmission frequencies and orbital parameters on each. The original data was derived from six sources: I) World Satellite Annual and the quarterly World Satellit_ Transponder Loadinq Reports (published by Mark Long Enterprises, Inc.). This includes all commercial satellites. 2) The Satellit_ Situation RepQrt (published by Project Operations Branch, NASA/GSFC). This document includes all earth orbiting spacecraft, but has only limited information on transmitting frequencies. 3) The Space Frequency Coordination Group (SFCG) Data Base. This includes both earth orbiting and deep-space spacecraft. (Owned by governments) 4) The Communication@ Center (Clarksburg, MD) data base. Includes all governmental and non-governmental geostationary spacecraft. 5) The _nternational Satellite Directory (Design Publishers). This overlaps (1), and because of its high cost, will not be used in future updates. 6) OuikTrak 4.0 (Low Earth Orbiter Tracking Software - AMSAT Corp.) Provides position, right ascension, declination, etc. for low earth or biting spacecraft. Orbital elements are obtained electronically from a database maintained by AFIT (Air Force Institute of Technology). In the past six months, additional data has been derived from the Space 2000 Database, which was purchased from Space Analysis and Research, Inc., Colorado Springs, CO; and from a database maintained by Dr. Wesley Sizemore at NRAO/Green Bank, WV. We have found the Space 2000 Database to be extremely useful in that it contains transmitter frequencies for many low-earth orbiting satellites (LEO's) not listed elsewhere. As described in previous reports, our database management and search software (HRS) has now been distributed to 25 users both within and external to the HRMS Project. We expect to release an updated version of the database itself in September 1993. Ill. OBSERVATIONAL STUDIES At the beginning of this year, we completed development of a 64,000 channel spectrum analyzer which simulated behavior of the Sky Survey system over a I MHz bandwidth. This spectrum analyzer was used in two different observation studies: I) A SETI search of 40 solar-type stars at the 203 GHz positronium hyperfine resonance was conducted from the NRAO-Kitt Peak, AZ facility. (A complete description of this observation is included in Appendix II.) 2) An observational experiment was conducted using a 30-meter antenna at the Georgia Tech Research Corporation/Woodbury Research Facility in order to characterize the nature of interference from geostationary satellites transmitting in the 3.7 - 4.2 GHz frequency band to the Sky Survey element operating in that band. A complete description of, and results from this experiment are given in Appendix Ill of this report. IV. CONCLUSION In the remainder of this grant year we expect to complete our latest updating to the HRS (_RMS BFI _earch) data base and distribute it electronically to all users. Likewise, we will use information about the upcoming launches of L-Band satellites in the mobile satellite service (MSS) in order to help determine those frequencies most at risk, and which should be observed in the 1994 OVRO deployment of the Sky Survey prototype system. V. REFERENCES Steffes, P.G. and D.R. DeBoer, 1993a. A SETI Search of Nearby Solar-Type Stars at the 203 GHz Positronium Hyperfine Resonance. Presented at the 1993 Bioastronomy Symposium; Progress in the Search for Extraterrestrial Life, p. 30. Steffes, P.G. and D.R. DeBoer, 1993b. A SETI Search of Nearby Solar-Type Stars at the 203 GHz Positronium Hyperfine Resonance. Submitted to Icarus. APPENDIX A: A SETI Search of Nearby Solar-Type Stars at the 203 GHz Positronlum Hyperfine Resonance PAUL G. STEFFES and DAVID FLDeBOER The development of advanced millimeter-wave technology has made it possible to construct low noise receivers and high power transmitters comparable to those available at much lower frequencies. Thls techr_!_0gy, plus certain physical characteristics of the millimeter-wave spectrum suggest possible advantages for use of this wavelength range for interstellar communications. As a result, a SEn type search has been conducted for narrow bandwidth signals at frequencies near the positronium hyperfine spectral line (203.385 GHz), a potential natural reference frequency. A total of 40 solar type stars within 18 parsecs were observed, in addition to 3 locations near the galactic center using the NRAO 12-rooter millimeter-wave radio telescope at ICJtlPeak, Arizona. No detections were made at the detection threshold of 8x 10.20w/m2 ineach of two linearpolarizations. Future observations will be made with a higher resolution fast Fourier transform spectrum analyzer (FFTSA) which should improve sensitivity by an order of magnitude, and reduce required observing time. 1993 Bioastronorny Symposium ABSTRACTS - Page 30 APPENDIX B: A SETI Search of Nearby Solar-Type Stars at the 203 GHz Positronium Hyperfine Resonance Paul G. Steffes and David R. DeBoer School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta, GA 30332-0250 Submitted to August 1993 Manuscript: 9 Tables: 1 Figures: 1 Proposedrunninghead: Millimeter Wavelength SETI Observation Mail proofsto: Paul G. Steffes School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta, GA 30332-0250 Tel: 404 894 3128 Fax: 404 853 9171 Internet: psl [email protected] AI .,LT.g6.CI The development of advanced millimeter-wave technology has made it possible to construct low noise receivers and high power transmitters comparable to those available at much lower frequencies. This technology, plus certain physical characteristics of the millimeter-wave spectrum suggest possible advantages for use of this wavelength range for interstellar communications. As a result, A SETI (_Search for Extraterrestrial Intelligence) type search has been conducted for narrow bandwidth signals at frequencies near the positronium hyperfine spectral line (203.385 GHz) a potential natural reference frequency. A total of 40 solar type stars within 23 parsecs were observed, in addition to 3 locations near the galactic center. No detections were made at the detection threshold of 10"19w/m, 2in each of two linear polarizations. Future observations will be made with a higher resolution Fast Fourier Transform Spectrum Analyzer (FFTSA) which should improve sensitivity by an order of magnitude, and reduce required observing time. ii