On 12/12/13 13:57, John Hasler wrote:
1) Better front-end selectivity 2) Better front-end dynamic range
I don't really see how these help against all but the crudest jammers, which transmit pure CW carriers or are off frequency.
3) Directional antennas for fixed sites such as cell towers
That might help a bit, if you rejected signals near the horizon (which are good for navigation, but may be bad for time). However, to get full benefit from directionality, you'd need to run large phased arrays and steer their beams to track the individual satellites. As most military users want the navigation data, they would be better off with steerable beams.
The military also have the advantage of a broader, L2 signal, with a cryptographic chipping code.
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