4 ms·
The existing backup is the Russian GLONASS system, which many consumer chips support since the start of this decade or so, and there are two more constellations
by Artlav 10y ago
The existing backup is the Russian GLONASS system, which many consumer chips support since the start of this decade or so, and there are two more constellations being deployed, by ESA and China.
I'm not sure how you can test such things not in the production environment. The early development was done with the transmitters on airplanes, but i would guess that the jammability can't really be tested that way.
- paulgerhardt 10y agoGPS uses a certain frequency. Use the high side band for prod, the low side band for staging. Simple :)
- hamiltonkibbe 10y agoThe nice thing about PRN codes is that you can just use a different set of gold codes in the same band, as long as they have low enough cross-correlation
- brianwawok 10y agoYup my GPS watch does GLONASS. Have never tried GLONASS only, but GPS + GLONASS is a fair bit faster to lock on to.
- mikeash 10y agoMost smartphones do both now as well. iPhones got it starting with the 4S, and various Android devices support it. I believe it's a requirement to be able to sell them in Russia, but it benefits us all.
- selvakn 10y agoAnd India's own: http://www.thehindu.com/sci-tech/science/irnss-launch-indias-own-regional-navigation-satellite-system-takes-shape/article8531388.ece http://www.thehindu.com/sci-tech/science/irnss-launch-indias...
- WorldMaker 10y agoCommercial vendor Iridium as part of their "Iridium NEXT" constellation currently being deployed will have a secure alternative to GPS as well, their STL service. [1] [1] http://gpsworld.com/iridium-launches-alternative-gps-pnt-service/ http://gpsworld.com/iridium-launches-alternative-gps-pnt-ser...