May I also add that the bandwidth needed to pass every intercept back to an operator on the ground - probably through Satcom, would be very great. By having the man in the loop, he can filter out the "trash" and only send on the good gen thus relieving bandwidth.
Bandwidth is a big issue within ISTAR, and with the Government wanting more and more of it to sell off to commercial enterprise then the less we have to use - the better. (I have also heard rumours that the Gov't want to charge the MOD for the use of the EM spectrum and therefore we will have to minimise on the number of frequencies that we use).