Renowned Pentagon crazytech agency DARPA, which normally wouldn't touch a piece of low-hanging fruit with a bargepole, has announced a new plan which seems strangely practical and achievable. The idea is to develop a backup for satnav location systems using radio "signals of opportunity".
DARPA refers to the plan as "Robust Surface Navigation" (RSN), making it clear that we aren't on about nuclear missiles, smart bombs or other such things which use satnav - just military units or systems down on the ground. In some situations, such as "urban canyons" or forest with dense overhead foliage, such users often struggle to get a decent fix using satnav.
Hence DARPA would like it if US military navigation hardware could also sniff out other radio transmissions in the neighbourhood. These might be special nav beacons emplaced by US forces, but the scheme is aimed more at "radio emitters not originally intended for location and navigation (such as commercial communications satellites, commercial radio and television broadcast towers, or mobile telephone towers)", according to DARPA. It's intended "to counter localized jamming or global failure of the Global Positioning System (GPS) ... and to complement GPS capabilities in situations for which it was not intended".
The weird thing about this - in a DARPA context - is that it's fairly simple and do-able. Most mobile phones, using Google's free map software, can get some kind of fix - potentially a fairly decent one - by simply looking at the cell towers nearby. Any device equipped with Wi-Fi can tap into a database of MAC IDs and locations, and so get an idea where it is. Similar plans are eminently achievable using Bluetooth or other radio protocols.
Thus any modern smartphone - equipped with GPS, WiFi, cell and Bluetooth radios - is already potentially an RSN device. Indeed, various forms of "assisted GPS" are already routinely used.
So DARPA's RSN programme appears to be shooting at an open goal, really. Certainly at first sight, there's nothing very "DARPA hard" about this one.
Even so, the agency announced last week that it would award $22m to take RSN to Phase 2 - which will see the project move forward from studies to "a functional prototype of the RSN system [which] must solve the fundamental problem of navigation and geolocation in GPS-denied areas, especially in difficult environments of inside buildings and in urban canyons."
It seems very likely that something useful and functional will emerge from this quickly. It won't unexpectedly morph into something else, perhaps not very militarily useful (eg the internet, with which the agency was heavily involved at an early stage).
This doesn't seem like proper DARPA behaviour at all. Heads will probably roll once management find out about it. ®