The current trend is to replace such platforms with large business jets with satellite comms and do the vast majority of both the processing and control from the ground. Or even data fusion from all the other airborne sensors - and perhaps reflections from ground emitters to build a multi-polar passive picture.
https://www.flightglobal.com/news/ar...t-plan-445844/
https://rusi.org/sites/default/files...proof_3_jm.pdf