Assessment of the Possible Health Effects of Ground Wave Emergency Network (1993) / Chapter Skim
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Description of GWEN System
Description of GWEN System
Pages 13-24
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From page 13... ...
First, the electromagnetic pulse (EMP) produced by a high-altitude nuclear detonation could, over a large area, produce a sudden power surge that would overload unprotected electronic equipment and render it inoperable; in recent years, the Air Force has pursued an extensive program to protect critical electrical components by making them immune to the effects of the EMP-produced power surge.
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From page 15... ...
Message reception via LF RO terminals occurs at key bases throughout the 48 states, including main operating bases of SAC, dispersal bases, and LCCs. I/O and RO terminals are co-located with other manned communications systems at existing military installations; RNs would be unmanned.
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From page 16... ...
The actual GWEN signal at the EF carrier frequency consists of intermittent transmissions of packets carrying 644 uncorrelated MSK bits. That is equivalent to a continuous MSK signal turned on and off as packets are transmitted.
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From page 17... ...
FIGURE 2-2. Minimum shift keying (MSK)
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From page 18... ...
Antenna type Antenna height Number of top loading elements Ground plane radius Number of buried copper radial wires Input power Antenna system efficiency Radiated power Base-fed, top-Ioaded monopole 299 ft 12 100 5 kW 40-65% 2-3.2 kW 18
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From page 19... ...
Two types of geometric clependencies influence electric field strength at a distance. The first is the usual I/r spreading loss that occurs in the far field of the transmitting antenna as a simple result of the conservation of energy for propagation in a lossless medium.
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From page 20... ...
Ground level electric and magnetic fields from GWEN EF antenna radiating the design maximum peak power of 3,200 W Typical radiated peak and average powers are 2,000 W and 28 W
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From page 21... ...
Electric field strength at 10 m height vs. horizontal distan from GWEN UHF ground-to-air antenna radiating design maximum peak power of 70 W
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From page 22... ...
~ cat Populations around 40 proposed GWEN RN sites have been estimated by examining U.S. Geological Survey maps of randomly chosen candidate locations for each site.
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From page 23... ...
TABLE 2-3. Numbers of Houses Within SLX Contiguous Concentric Zones Around 40 RN Sites.
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