The kill assessment function requires minimal radar resources, as it serves merely to detect the fragmentation of the selected target by the interceptor. If the prior discrimination has ruled out the presence of additional lethal targets, fragmentation of the selected target is confirmation of kill.

The very-long-range sea-based X-band radar (SBX) currently being used as a test asset would provide Pacific coverage based in Adak, Alaska, where moorings for it currently exist. It is shown with 360-degree coverage because it is turntable mounted, but its array has a limited field of view. Additionally, two medium-range AN/TPY-2 class X-band radars deployed in Japan and southeastern Europe (eastern Turkey) provide the precision tracking capability and kill assessment to enable SLS with the concurrent viewing that the committee described earlier. These radars, coupled with the recommended GMD-E interceptors, provide SLS engagement battle space over virtually all populated portions of North America for the midcourse phase of the ICBM threat trajectory—i.e., they provide homeland defense.

Details of the analysis (a homeland defense-oriented analysis process) utilizing radars and radar deployment presented above are presented in the next section.



This section summarizes the results of detailed engagement analyses used to assess the effectiveness of the recommended GMD-E for the missions for homeland defense against any limited attack: Iranian and North Korean threats were used as cases for analysis. In each case provided below, interceptor basing was assumed at FGA, and at a northeast CONUS location, e.g., Fort Drum, New York; Caribou, Maine; or Rome, New York. An additional trial location at Grand Forks, North Dakota, was also evaluated but found redundant and unnecessary.

Coverage of GMD Evolution Against Threats from Iran

The following section considers threats from Iran and compares single-shot and SLS coverage for minimum-energy, lofted, and depressed trajectories.

Figure 5-9 shows the maximum footprint where only one shot is possible in blue using the committee’s proposed architecture for homeland defense. It also shows the footprint for at least one SLS cycle in red.5 Interceptors are assumed to be launched 10 sec after entering an X-band radar’s track capability and must be observed by X-band radars for at least 50 sec.


5Figures 5-8 to 5-14 were generated from the committee’s analysis using Google Earth. ©2011 Google, Map Data ©2011 Tele Atlas.

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