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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.
“The Times”28 pages
- 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…
UNCLASSIFIED/ ,i, without being sensitive to a frequency of cm.
This is the minimum functionality required to constitute a communication link. Signal
strengths of the respective GW generators would need to be sufficient to overcome link
loss, coupling losses, and noises sources. Signal to noise considerations and link
budgets are covered in further detail in Section 3.1.
2.1 HFGW GENERATORS {TRANSMITTERS)
2.1.1 HFGW Generator Concepts
Several sources for HFGWs or means for their generation exist. The first generation
means is the same for gravitational waves (GWs) of all frequencies and is based upon
the quadrupole equation first derived by Einstein in 1918. A formulation of the
quadrupole that is easily related to the orbital motion of binary stars or black holes,
2
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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.