DOW-UAP-D140, AAWSAP DIRD, High-Frequency Gravitational Wave Communications, April 2010

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High-Frequency Gravitational Wave Communications Prepared by: Acquisition Support Division (DW0-3) Defense Warning Office Directorate for Analysis Defense Intelligence Agency AAP Person 77 Administrative Note COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one in a series of advanced technology reports produced in FY 2009 under the Defense Intelligence Agency, Defense Warning Office's Advanced Aerospace Weapon System Applications (AAWSA Pro ram. Comments or uestions pertaining to this document should be addressed t AAP Person 1 AAWSA Program Manager, Defense Intelligence Agency, ATTN: CLAR/ DWO-3, Bldg 6000, Washington,

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1.2 Definition of High-Frequency Gravitational Waves ....................................... 1 2.2.3 Quantum Back-Action Limit................................................................. 16 3.3.3 The Impact of Phase Noise Improvements on Phase Shift Encoding ... 29 3.3.4 The Impact of Frequency Noise Improvements on FDMA and FHSS..... 30 3.4 Possible Future Upgrades to the FTS Devices ............................................. 30 3.4.1 Propagating Signals From Optical Lattice Clocks for Timing ................ 31 3.4.2 In Navigating and Mapping Interplanetary Geoids .............................. 31 4.3 Interplanetary Navigation and Geoid Mapping to 2050 .............................. 34

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Appendix C: Perturbative Photon Fluxes Generated By High-Frequency Gravitational Waves and Their Physical Effects .................................... 52 Figure 1. Communication Link Block Diagram ........................................................ 2 Figure 2. Change in Centrifugal Force of Orbiting Masses, Afct, Replaced by Change in Tangential Force, '1ft, to Achieve HFGW Radiation ............................... 3 Figure 3. Circular Resonator Geometry Using Infrared Excitation .......................... 8 Figure 4. Radiation Pattern Calculated by Landau and Lifshitz (1975) ................... 8 Figure 5. GW Flux Growth Analogous to Stack of N Orbital Planes ......................... 9 Figure 6. Stack of Circular-Wave-Guide Plates With Typical Molecule Jerks, Af's ... 9 Figure 7. Omni-Directional Nature of the HFGW Radiation Pattern....................... 10 Figure 8. Predicted Relic GW Energy Density as a Function of Frequency............. 11 Figure 11. The National Astronomical Observatory of Japan 100 MHz Detector ... 14 Figure 12. Detection Photons Sent to Locations that are Less Affected by Noise.. 15 Figure 13. Quantum Back Action as a Mechanism for Creating the Standard Quantum Limit..................................................................................... 17 Figure 14. Schematic of Ultra-Sensitive HFGW Detector....................................... 21 Figure 15. Fractal Membrane Component of Li-Baker Detector Exhibited in Planar Figure 16. Conceptual SNR Fill Factors: Signal and Noise Components ................ 23 Figure 17. A Block Diagram of a Typical Link Budget............................................ 24 Figure 18. A Proposed Near Earth Distribution of Frequency Time Standard........ 26 Figure 19. HFGW Supplemented Remote Terminal Design.................................... 27 Figure 21. The Impact of Phase Noise Improvements on Phase Shift Encoding ... 29 Figure 22. The Impact of Frequency Noise Improvements on FDMA and FHSS ..... 30 Figure 23. The Earth's Associated Lagrangian Points ........................................... 31 Figure 24. HFGW Com Space Application Development Roadmap, Estimated Figure 25. A GW Pair on Earth as Used by a Lunar Mission ................................... 34 Figure 26. A GW Pair on Earth and on the Moon, as Used by a Mission to Mars .... 35 Figure 27. A GW Pair on Earth and on Mars for an Outer Planetary Reference

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High-Frequency Gravitational Wave Communications • Fourteen laboratory high-frequency gravitational wave (HFGW) generators (or transmitters) have been proposed in the past 45 years in peer-reviewed journal articles. • The most promising laboratory HFGW generators are those that utilize very large numbers of sub-microscopic radiation elements. • The Piezoelectric Approach to HFGW generation is best for the proof-of­ concept test and the proposed IR-excited Molecules Approach is best for an operational communications HFGW transmitter. • Ten different HFGW detectors (or receivers) have been proposed since 1978 and reported in peer-reviewed journal articles. • Several different HFGW receivers can be utilized for communication, but the proposed Li-Baker detector (plans & specification development in Appendix B) shows the most promise (underlying concept in Appendix C). The Li­ effect, upon which the Li-Baker detector is based, is not so new that it is untested in the literature. At least nine peer-reviewed research publications concerning the theory have appeared following the initial peer-reviewed article by Li, Tang and Zhao (1992). • Because HFGW communications are carried on an extremely narrow beam directly through the Earth, there is a very low probability of interception. • Theoretical results confirm that the Li-Baker detector is photon-signal limited, not quantum-noise limited-that is, the Standard Quantum Limit is so low that a properly designed Li-Baker detector can have sufficient • Utilizing the IR-excited Molecules HFGW generator approach and the Li­ Baker detector, the theoretical information-transfer rate over 7,000 km of distance, beamed directly through the Earth, is about 1.9 x 106 bits per • A means of propagating a Frequency Time Standard may be one viable early low-bandwidth application for HFGW communications. • HFGW sources on the Earth, the Moon, and Mars may act as reference standards for interplanetary navigation, with the advantage that they cannot be shielded or shadowed by planetary masses. Plasma interference seen at planetary entry would be eliminated, and precise charting of Lagrangian points would be possible.

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Of the applications of high-frequency gravitational waves (HFGWs), communication appears to be the most important and most immediate. Gravitational waves have a very low cross section for absorption by normal matter, so high-frequency waves could, in principle, carry significant information content with effectively no absorption unlike electromagnetic (EM) waves. Multi-channel HFGW communications can be both point­ to-point (for example, to deeply submerged submarines) and point-to-multipoint, like cell phones. HFGWs pass through all ordinary material things without attenuation and represent the ultimate wireless system. One could communicate directly through the Earth from Moscow in Russia to Caracas in Venezuela-without the need for fiber optic cables, microwave relays, or satellite transponders. Antennas, cables, and phone lines would be things of the past. A timing standard alone, provided by HFGW stations around the globe, could result in a multi-billion dollar savings in conventional telecom systems over ten years, according to the recent analysis of Harper and Stephenson (2007). The communication and navigation needs of future magneto hydrodynamic (MHD) aerospace vehicles, such as the MHD aerodyne (www.mhdprospects.com), which is high in electromagnetic interference, similar to plasma interference seen at reentry,