Topic summary
Radar blackout
Extracted from the Wikipedia article Nuclear blackout.
Blackout and missile defense
Radar blackout further confuses these issues. Inherent to the formula above is the fact that higher frequencies are blacked out for shorter times. This suggests long-range radars should use as high a frequency as possible, although this is more difficult and expensive. The US PAR was initially designed to operate in the VHF region to allow it to be extremely powerful while also relatively low-cost, but during the design stage, it moved to the UHF region to help mitigate this effect. Even then, it would be heavily attenuated.