Documents / Report
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.
“BEAMS”17 pages
UNCLASSIFIED//F811. 8FFll!l*L 1!1!11! l!IHL"i' received signal, S, is (1.48xl0 14)/(7xl06)2 = 3 wm· 2, more than adequate for an effective communication system. With this configuration, the width of the needle-like, narrow HFGW beam at the receive end is (2.3x10- 4 ) x (7x10 6 ) = 1.6 km, and multiple HFGW carrier frequencies can be used, so the signal is very difficult to intercept, and is therefore useful as a low- probability-of-intercept (LPI) signal, even with widespread adoption of the technology. From Equation (2) the amplitude A of the HFGW at 7,000 km with the HFGW frequency (twice the IR frequency of VGW = l.2x10 14 s· 1) given by: A= 1.2sx10·18 (S/VGW )'1' = l.SxlQ-32 (in dimensionless units or m/m), which would be detectable by the currently designed Li-Baker HFGW detector. Since the exact frequency and phase of the HFGW signal is known (unlike the stochastic relic HFGWs, for which the Li-Baker detector was designed), a much more sensitive, optimized HFGW detector will likely be developed. As shown in Figure 8, from Grishchuk (2008), there will be negligible relic HFGW noise at the IR HFGW generator's frequency of l.2xl0 14 s- 1 and no other cosmic sources at these frequencies are currently hypothesized. Prior to the proof-of-concept test, one can assume a noise figure at the Li-Baker detector of 10-s wm- 2 . . . . 1 ◊-12 u , n = 1.0 _gw . 1 0-20 10·10 10·" 10° Frequency v, Hz Figure 8. Predicted Relic GW Energy Density as a Function of Frequency 11 UNCLASSIFIED//r;Oll oi;i;1,;;1•k llili O•lk¥
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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 57 pages are in the text index: search them above, or from the library's search.