It's easier than that - use two blocks of different repetition frequencies (which gives two different Nyquist velocities), get two velocity readings. Some basic number theory will get you the right answer.
Using two different carriers is going to alter the Nyquist velocity by such a small amount that it's not worth doing. Unless the carriers are very widely separated (go from say, 2.7 GHz to 5.8 GHz) but this requires a wideband (and necessarily low gain) antenna.
That's not to say that FHSS is not used by weather radar - its purpose is to improve the quality of measurements by increasing the number of statistically independent samples that get averaged together.
There's also the effect of water absorption causing corrosion to metal parts, and promoting water absorption in certain plastic fuel tanks. The latter has resulted in a lawsuit with motorcycle manufacturer Ducati, where they agreed to replace the tanks that were swelling and in some cases, rupturing due to water absorption. This only happened in the US, after E-10 fuel became popular. Regular octane does not absorb water.
My Ducati's past warranty, so the tank replacement offer doesn't cover me, once my tank swells or ruptures, I'm hosed.
Even *if* you posit a dystopian future where the $BEC controls everything, there will *still* be PCs, because *someone* will still have to produce data. They may become much less common, but a PC, or a PC-functional device, *will* be necessary.
My worry is that this same phenomenon will lead to less data/content being produced. We're in a situation now where PCs are in virtually every home, every kid has access to one, and ones who are curious/lucky enough will stumble upon some interest of theirs that they can use this hardware to explore (examples: home recording studios, 3D modelling, CAD of various kinds, software development tools.) In a tablet-and-smartphone world, PCs will get expensive, and out of the reach of most kids/amateurs, who'd have no opportunity to explore their creativity.
Blessed be those who initiate lively discussions with the hopelessly mute, for they shall be known as Dentists.