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Foretesting a Soviet ABM System

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Soviet ABM System

  
atmosphere as rapidly as possible, leaving a minimum of time after target discrimination for the enemy's anti-ballistic-missiles to reach them.
 
In the fall of 1961 and 1962, however, the Soviets performed exoatmospheric nuclear experiments at their ABM research center near Sary Shagan. There were never any atmospheric tests there. U.S. intelligence had been aware of two new research radars, code-named Hen House and Hen Roost, at Sary Shagan, but the first signals from either were intercepted only when some Hen House pulses were reflected from the ionized cloud generated by a nuclear explosion during these tests.
 
The intercepted Hen House signals had peculiar characteristics. Most notably, their carrier frequencies were in the VHF range, a very low frequency relative to the L and S bands normally used for U.S. long-range radars. The Soviets had other VHF radars, for example the newly deployed Tall Kings for early antiaircraft warning; but the Hen House signals turned out to have much more information content than is needed for mere early warning. For ABM use the low frequency should have serious disadvantages, not only in tracking ICBMs but even in their early detection. Theoretically, uncertainties in propagation, both in the lower troposphere near the earth and in penetrating the ionosphere to the target vehicle, might create such errors in measurement as were thought to render VHF quite unsuitable for U.S. tracking applications. Furthermore, it might be presumed that any nuclear explosion in the radar path would blind a VHF system.
  
The longer wavelength does have its own virtues, however. It is harder to jam or deceive with decoys, and it makes for a cheaper system. It would maximize the radar cross-section of target U.S. ICBMs. Such a system would be a natural extrapolation from previous Soviet radar technology. The logical interpretation of the Sary Shagan tests was that the Soviets were in fact exploring the feasibility of a new exo-atmospheric intercept system, using VHF radar, in defiance of our endo-atmospheric doctrine.
  
Postulated Soviet System  
  
In 1963 the U.S. Army's missile electronic warfare organization at White Sands, under the stimulation of inductive argument from a CIA liaison officer (this reporter), became convinced that Soviet researchers had found, or were finding, ways to get around the diffi
        
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Posted: May 08, 2007 08:15 AM
Last Updated: May 08, 2007 08:15 AM