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Defense Intelligence Reference Document High-Frequency Gravitational Wave Communications

Defense Intelligence Agency · 57 pages · text from the file's own layer

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.

  • p. 3 …the FTS Devices ............................................. 30 3.4.1 Propagating Signals From Optical Lattice Clocks for Timing ................ 31…
  • p. 4 …Omni-Directional Nature of the HFGW Radiation Pattern ....................... 10 Figure 8. Predicted Relic GW Energy Density…
  • p. 5 …The Piezoelectric Approach to HFGW generation is best for the proof-of- concept test and the…
  • p. 6 …Antennas, cables, and phone lines would be things of the past. A timing standard alone, provided…
  • p. 8 …over the time interval !1t, s; that is, the jerk or shake of the two masses…
  • p. 9 …The usual difficulty with HFGWs generated by nuclear reactions is the small dimensions of their nuclear…
  • p. 22 …the initial momentum uncertainty, dt is the time of the future measurement, and m is the…
  • p. 23 …Eis the effective energy contained within the detector cavity summed over the detection averaging time, and…
  • p. 24 …The temporal quality factor in the Li-Baker detector arises from averaging the signal over time…
  • p. 28 …Another way to increase Q is to arbitrary increase sample times of the signal. This technique…
  • p. 29 …There is also a hidden integral here which occurs over the sample time, which is understood…
  • p. 30 …3.3 FREQUENCY AND TIME STANDARD The first application of HFGW to the distribution of frequency…
  • p. 31 …The arrival times of the received PPS signals could be compared via time difference of arrival…
  • p. 32 …The universal nature of the HFGW frequency and time standards are especially helpful. The following telecommunication…
  • p. 33 …the search space is reduced, speeding acquisition. • Ultra-fast acquisition allows more efficient TDMA, or Time…
  • p. 34 …For a 5 μsec acquire test time, the result is Tacq = 150 x 150 x 16…
  • p. 35 …At this precision one could measure the time delay caused by changing once centimeter in height…
  • p. 36 …the problem of mapping the positions of the Lagrangian points, which vary slightly over time. 3…
  • p. 38 …As prototypes show promise they could be transitioned to device development, the first time that industry…
  • p. 39 …For instance, if there were one GW source on Earth, and one GW source on the…
  • p. 41 …Nonlinearity improves the focusing process and h goes to one in finite time, producing a singularity…
  • p. 45 …and Stephenson, G.V. (2007), "The Value Estimation of an HFGW Frequency Time Standard for Telecommunications…
  • p. 46 …Thesis, The University of Birmingham, January. Kippenberg, T. J. and Vahala, K. J. (2008), "Cavity Optomechanics…
  • p. 49 …time of future measurement, s effective energy contained within the detector cavity summed over the detection…
  • p. 50 …The project plan and timing are described below under separate headings for each component of the…
  • p. 51 …coils that superimpose upon the constant applied magnetic field a time-varying component at low frequency…
  • p. 53 …photon events, and has very good time resolution. The disadvantage is its cost and complexity. This…
  • p. 55 …Cryogen-free (more accurately, the cryogen is completely enclosed and re-cycled each time the magnet…
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4.5 2050 and Beyond ....................................................................................... 37
5.0 Acknowledgements ........................................................................................ 37
6.0 References ..................................................................................................... 37
Appendix A: Nomenclature ................................................................................... 44
Appendix B: Li-Baker HFGW Detector ................................................................... 45
Appendix C: Perturbative Photon Fluxes Generated By High-Frequency
Gravitational Waves and Their Physical Effects .................................... 52
Figures
Figure 1. Communication Link Block Diagram ........................................................ 2
Figure 2. Change in Centrifugal Force of Orbiting Masses, .dfct, Replaced by Change
in Tangential Force, Aft, 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, .df'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 9. Birmingham University HFGW Detector ................................................. 13
Figure 10. INFN Genoa HFGW Detector ................................................................ 13
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
Form .................................................................................................... 21
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 20. Acquisition Search Space Improvement Accruing From HFGW FTS ...... 28
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
Timeline .............................................................................................. 32
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
Pair ...................................................................................................... 35
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