Comment Re:Octave (Score 1) 205
You can also carry it around in your pocket should you need it. (Together with Maxima, actually.)
Because The Fancy Article is talking about filing flight plans, and since a central authority has to have a center, and Washington is the location of the central controlling authority in the US.
It doesn't have to be a federal center; in fact, it makes little sense to have one for that.
Why do you want a central controlling authority in the first place, whether or not it is geographically sharded?
Because hardware-wise, it's simpler to implement (basically COTS), with potentially lower amortized costs.
Why is there any need for any sort of database, 4D or otherwise?
Because computational geometry is the fundamental nature of the problem, from which the structure of the solution naturally arises. Just like using wheels is a natural solution to moving things on the ground (to make a car analogy). But of course you'd suggest mechanical limbs, because that's what apparently seems more natural to you.
i can't go into the details because i was working in a secure environment
What?
but basically even though i was the one that wrote the code i was taken aback that *python* - a scripted programming language - was capable of such extreme processing rates
Given that these are basically FFI memory accesses, I don't think how one could find that surprising. Although it would be interesting to see it stacked up against DataDraw.
Would this call for custom RF hardware, which could be expensive, plus licensing a band for it? A cell modem module seems cheaper to me. But aside from some kind of data broadcast, which seems inefficient, that would still require some way of finding the closest drones to tell them that you're approaching, ergo someone who knows where everyone is.
I don't know, but to me, the conceptualization of the problem using a central authority seems very simple. Represent all drone routes or operation areas as 4D polyhedra. Every request for reservation is represented as at least one such polyhedron. A central authority checks if it doesn't intersect any existing assigned routes or areas, using computational geometry in 4D. If it doesn't (perhaps with checking for minimum clearances as well), the request is granted and the requested region is added to the data structure. If not, the request fails. An interesting question is whether the central authority should simply indicate failure or whether it should include hints on alternate routes, if feasible.
For performance, using persistent data structures could help: even if write access has to be serialized, with persistent data structures, intersection checks can be done in parallel with processing other requests, with most rejections indicated at this stage. When the serialized write/commit gets to check it again against the most current version of the data (which is basically insert-only, and only incrementally slightly bigger than in the first check), most failing requests will already have been eliminated by this point in processing the request. Only competing requests arriving concurrently could cause a rejection at this phase, and these are unlikely. (The whole data structure also has to be periodically GC'd - by essentially cutting out all polyhedra not reaching along the time axis into the present - but with such a specialized data structure, perhaps circular references could be avoided and the whole thing compacted easily. Again, an interesting problem.)
Provided that drones don't veer off their corridors, there's no potential for collision. And if they happened to veer off because their navigation is off (assholes with GPS jammers), the real-time communication of their current position (similar to AIS) wouldn't help you anyway because the data would be wrong. In this worst case, you'd need some really fancy gear to give drones the kind of awareness in urban 3D space (modulo static building, of course, that's just a terrain map) where marine vessels manage with a simple 2D radar and a guy eyballing the blips. I'm not sure people would accept these extra expenses easily. And spatiotemporal reservation even solves the problem of intermittent communication, as it doesn't actually have to work in real time.
Garbage In -- Gospel Out.
