4 ms·
I wonder how many implementations of the calculations there are. Do all the commercial GPS and phone manufacturers write this on their own, or is there a tested
by shoover 12y ago
I wonder how many implementations of the calculations there are. Do all the commercial GPS and phone manufacturers write this on their own, or is there a tested version they can license?
- colechristensen 12y agoA significant portion of the calculation is usually done in hardware (less 'written' more 'designed'), and yes these things are licensable. Most, though, have no interest in fabricating their own chips (and can't get much out of customizing one) and buy chips off the shelf. There certainly are several independent implementations.
- maxerickson 12y agoThis article has been posted here a couple of times: http://www.aholme.co.uk/GPS/Main.htm http://www.aholme.co.uk/GPS/Main.htm discussions: https://hn.algolia.com/?q=gps#!/story/forever/0/http%3A%2F%2Fwww.holmea.demon.co.uk%2FGPS%2FMain.htm https://hn.algolia.com/?q=gps#!/story/forever/0/http%3A%2F%2... It mentions an earlier project also done by an individual: http://lea.hamradio.si/~s53mv/navsats/theory.html http://lea.hamradio.si/~s53mv/navsats/theory.html So even a few individuals are able to wrap their heads around the problem (I guess commercial projects would also tend to have one or two people doing significant amounts of the work).
- colechristensen 12y agoA single, mildly impressive engineering graduate student should be able to construct a functional hardware GPS receiver from scratch in a year or so.