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This Defense Intelligence Reference Document was prepared by the Defense Intelligence Agency under its Advanced Aerospace Weapon System Applications (AAWSA) program, is dated 6 April 2010 and is part of a series of advanced technology reports produced in FY 2009. It reviews proposed laboratory generators and detectors of high-frequency gravitational waves for communications. It favors an infrared-excited molecules transmitter and the Li-Baker detector, estimating about 1.9 million bits per second over 7,000 km through the Earth. It also discusses timing standards and interplanetary navigation uses.
UNCLASSIFIED/ ,'l"e" Cl"l"!e!•t tl9E CHE I High-Frequency Gravitational Wave Communications Summary • 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 sensitivity to observe HFGWs of amplitude A,::::; 10-32 m/m. • 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 second. V 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. UNCLASSIFIED//F8R 8FFI@Itllt ""I! one I
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 57 pages are in the text index: search them above, or from the library's search.