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New Air Force Satellites Launched To Improve GPS (techcrunch.com)
AmiMoJo writes: This morning, the United Launch Alliance (ULA) successfully launched a Boeing-built satellite into orbit as part of the U.S. Air Force's Global Positioning System (GPS). This $131 million satellite was the final addition to the Air Force's most recent 12-satellite GPS series, known as the Block IIF satellites. The GPS Block IIF satellites were launched to improve the accuracy of GPS. Before the Block IIF series, the accuracy of GPS could be off by 1 meter. With the new Block IIF satellites in place that error is down to 42 centimeters.
42cm until they scramble it in times of war
RTK GPS is accurate to within 1-2 cm lat/long and typically 2-3 cm alt. For now that is about the best accuracy a civilian can get.
yes or the 10cm cm with DGPS. Buckyballs will allow for accuracy to about 1mm if they are used for time sync on satellites.
phones already use cell towers and wifi networks which are a lot more accurate and faster than GPS
I am not sure about this, but I had thought that phones use cell towers and wifi to get general idea where they are at and then use GPS for more accuracy. Without the inital gross location, GPS takes a lot more time to sync up.
No they aren't. They use a lot less battery power, but they provide far less accurate results. But if you want to keep the location on for an extended period, you need to use network or you'll kill your battery.
Want proof? Look at your maps app- it still uses GPS. And it eats through battery- you can feel your phone heat up when using it, and you can see the battery drop like a rock when navigation is on.
I still have more fans than freaks. WTF is wrong with you people?
You do understand that GPS has non-military and even military purposes that don't involve dropping bombs right?
http://www.nationalgeographic.com/foodfeatures/feeding-9-billion/
GPS can help agriculture be more efficient, thus providing more output per acre, and thus more food for those very children you are so concerned about feeding.
And if you are so concerned about feeding children, may I suggest getting off your fat ass, and going to Africa to see how massively complicated the problem actually is, instead of being the arm-chair quarterback.
You don't need new gear to benefit from these IIF block birds.
The follow on ones, up next will also be backward compatible...though they will transmit an additional civ signal along with transmitting the old backward compatible one as well, to get the new (second) channel you'll likely need new gear, it's years away.
What are they planning, drones with sniper rifles?
That is probably more from the constant display update plus the transmit and receive from the data network. Now interestingly I use navit on my phone with the mapset of planet.bin (about 18 GB now) and even with the GPS off it will eat battery if I am moving around the map. Interestingly turning the GPS on or off doesn't appreciably change the battery usage when doing this. If I have had GPS on on the phone before starting navit it will have my location immediately but if not it will take a bit until it has a lock so that seems to imply that even having GPS means it is ready to go when something requests it. I have left GPS on on my phone with nothing actually polling it and while it does drain the battery noticeably faster, I will lose about 1/2 a day charge over about 3 days in this case, it isn't like it is massively eating through battery. Having a couple of very nice GPS modules that are a lot more sensitive and capable than what is available in a cellphone they only draw a max of 80mA@3V and that is only during the a cold boot acquisition and lock.
Time to offend someone
all that "post-processing" could probably be done on the fly if you really needed to, provided things like base stations still existed,
WAAS and DGPS ground stations are all over the place, and you can access the DGPS correction data using a wireless modem. It is used for maritime and aviation navigation at a minimum.
The concern that created SA was not for long-term stationary measurements, but on-the-move guidance for troops and weapons systems which would not have nearby fixed station correction data.