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AAWSAP DIRD, High-Frequency Gravitational Wave Communications, April 2010

U.S. Department of War · 2010-04-06 · 57 pages · text from the file's own layer

This Defense Intelligence Reference Document, DIA-08-1004-005, is dated 6 April 2010. The Defense Intelligence Agency's Defense Warning Office prepared it under the Advanced Aerospace Weapon System Applications program. It reviews proposed laboratory generators and detectors for high-frequency gravitational waves. It favors a piezoelectric approach for proof-of-concept tests, IR-excited molecules for an operational transmitter and the Li-Baker detector as the receiver. It estimates about 1.9 million bits per second over 7,000 km through the Earth and discusses timing standards and interplanetary navigation uses.

From the source:Release of 2026-09-18 Incident: 4/6/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD examines whether high-frequency gravitational waves could serve as a communications medium while avoiding the attenuation that limits radio-frequency systems. The report surveys proposed transmitter and detector concepts, argues that gravitational-wave communications could support secure point-to-point links, timing standards, and interplanetary navigation, and gives particular attention to laboratory generator concepts and the Li-Baker detector as possible building blocks for such a system. The document makes clear, however, that the entire concept depends on capabilities that had not been demonstrated in practice, including laboratory-scale generation and reliable detection of usable high-frequency gravitational-wave signals. It is an exploratory systems-oriented review built around a future communications concept.

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device. Therefore mobile devices, such as portable remote spaceborne terminals could
be typical users of such a navigational service. An example is depicted in Figure 19.
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Figure 19. HFGW Supplemented Remote Terminal Design
The navigational sensitivity of the HFGW receiver would depend on the frequencies
used in the HFGW FTS system, as the received CW HFGW signal would act as the
remote terminal's "built-in" frequency standard, replacing the need for internal crystal
oscillators or Cesium or Rubidium standards. An HFGW FTS carrier wave with a
frequency of 300 GHz with a wavelength of 1 mm would result in 3 pico-second type
time accuracy. The use of TDOA with these accuracies would allow for arbitrarily small
navigational errors.
3.3.1 Improvements Accruing from a HFGW Time Standard
The cost of the FTS infrastructure must be more than balanced by the benefit resulting
from that infrastructure if the cost is to be justified . Given that the GPS already
provides adequate navigation services for most applications, navigational benefits alone
would not justify the cost of an HFGW FTS system. However, in the case of a universal
HFGW FTS, there are additional benefits associated with applying the frequency and
time standards to standard telecommunications problems. The universal nature of the
HFGW frequency and time standards are especially helpful. The following
telecommunication benefits of an HFGW FTS system will be described in this section:
improvement in acquisition time from search space improvements, improvements in
modulation and coding efficiency from phase noise improvements, and improvements in
bandwidth efficiency from frequency noise improvements.
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Official release, from the pursue 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.