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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.
The dateline on the story is actually for Feb. 5. Spacenews.com also reported the launch was on Feb. 5.
RTK is more accurate than 42 cm. But that is not true GPS I suppose.
DGPS is accurate to 10 cm though.
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Do new satellites drop into the existing network but with improved accuracy? Or will you need an updated device to take advantage of it?
Nope, no sig
I thought that with the newest satellites, that capability had not been designed-in?
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Which is exactly why there's such a push for non-GPS and inertial technologies in the military. GPS is slow (to get a good track), inaccurate (depending on terrain and such), and easily spoofed.
Now you can be tracked within 42 centimeters of your actual location.
Before someone would have to go to the spot and take a second to look around for you.
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.
What are they planning, drones with sniper rifles?
A-GPS downloads the GPS almanac and ephemeris data from wifi or cell towers. That way the GPS unit doesn't have to wait for this information to be sent by the satellite.
If the signal is interrupted during the satellite download, it has to start again. This can happen if your GPS antenna is a tiny thing buried inside a cellphone...
RTK is more accurate than 42 cm. But that is not true GPS I suppose.
What? Why wouldn't using GPS for position information be "GPS"?
DGPS is accurate to 10 cm though.
If DGPS is "GPS" then so is RTK. Both require fixed station correction information. RTK adds in phase measurements of the GPS carrier signal to get to cm accuracy.
With differential GPS? Pretty darned accurate, like to the millimeter if you have time to wait... Just out moving around without a stationary reference? What ever the military thinks you need right now, down to about a meter on the expensive receivers, a bit more if you are depending on the cheap thing in your cell phone. If the military deems it necessary, they can induce just about any amount of error they wish...
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
New GPS satellites also carry a COSPAS SARSAT package which has two purposes
1. It detects existing digital satellite beacons, but since GPS birds fly over the whole planet constantly and pretty fast, it reduces the time from when you activate the beacon until your message is processed by a ground station. When rescue is life-saving, minutes count.
2. It is ready for future beacons that will have a "back channel" so that after you activate the beacon you can receive a message e.g. "Helicopter dispatched. Move to open ground if possible to effect rescue" or "Storm too powerful. Rescue abandoned. Stay warm, we'll try again at dawn".
COSPAS SARSAT (basically "Search and Rescue* satellite" in both English and Russian) is the global distress system, today it uses Geostationary comms satellites and fast low weather satellites to receive distress signals. The Geo sats can't tell where you are while the LEO ones are often not overhead when you most need them so it can take up to an hour for them to even see you. GPS sats are best of both world, there are so many you'll always get seen and they're moving pretty quickly so they can figure out where you are even if you don't know.
* Although actually it's just Rescue these days, the whole point of using the satellites is to stop searching mountains and oceans and just go straight to where the distress beacon is and rescue people immediately. The oldest analogue beacons had a multi-mile search radius, so it was better than nothing but you did need to search, digital beacons are usually putting rescuers within a hundred metres of the target and sometimes literally right on top of them.
Besides, in time of war, the enemy will just track you using your cellphone transmitter and drop a bomb on you that way. There's the old saying, "there's no such thing as 'close enough', except in horse shoes, hand grenades ... and atom bombs."
Battery usage depends on the chipset, with newer chipsets using less power. For example, I've had a misbehaving app leave on the GPS on my Nexus 5X, and I still got battery life of about 8 hours. That's not good battery life, but the power consumption was low enough that I didn't notice the phone heating up in my pocket, and I was able to get through a day at work before it went into power saving mode.
My impression is that the real killer with the map app is screen usage. If you leave the map in the foreground, it will leave the screen on, and that drains power like crazy. Even if you hit the power button to turn the screen off, it will keep updating what it's showing on the screen, and that will continue to eat a lot of power. You can save a lot of power by going back to the home screen or another app, which lets you get voice prompts but avoids the power drain from the screen rendering.
There's no point in questioning authority if you aren't going to listen to the answers.
phones already use cell towers and wifi networks which are a lot more accurate and faster than GPS
No on the accuracy. Cell tower based location determination is accurate to about a city block and provided that you have WiFi with a known location you could get accuracy to about 2 buildings. The quicker to acquire seems like it may be reasonable but by having a better guess of your location you can get a lock quicker with GPS.
Time to offend someone
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
Hell there are even autonomous GPS guided haul trucks now that drive optimized paths to and from the autonomous shovels that also rely on GPS. Granted it is RTK that they use to get the accuracy necessary but that is just GPS with some base stations that provide corrections. If you can save 1% on fuel and keep those expensive shovels and truck not waiting you can save a lot of money and not waste resources.
Time to offend someone
I know how RTK works, I've built my own RTK systems. Seeing that there are differences in RTK, some might say it isn't traditional GPS, so I left the variable in my comment in case someone had a pedantic argument about how it is interpreted making it something different.
I remember when SA was on, and there were plenty of ways to improve your accuracy, only that back then it wasn't instantaneous and involved post-processing (which we used to do to everything). So ya if you were out in the field walking along with your GPS, it could be out by a lot... However if you stood in one place for a few minutes, collected a few hundred points and then averaged them out statistically after the fact, you could get very accurate results. If you really wanted even better accuracy there used to be a ton of "base stations" which I guess are likely antiquated now, which where in known locations that transmitted their locations, which you could also adjust your values to to achieve even greater accuracy... So there were plenty of ways around SA, just not really at the time of collection. However given today's technology, all that "post-processing" could probably be done on the fly if you really needed to, provided things like base stations still existed, and you didn't need to move around a whole lot at the same time. I used some pretty cheap devices back in the day, that with proper usage could give perfectly acceptable result if you know what you are doing. As I recall, a bigger threat back then was that every device wanted to use it's own proprietary standards, codes, and interface to force you to buy their overpriced (and clunky poorly designed I might add) software to use your own data (Remember Kodak digital cameras? Same Idea.) which was a huge PITA, requiring either to pony up for the software or reverse engineering, or finding tools that other had made (this was before Google)... Of course it there were some pretty collaborative GIS communities at the time .
Also as you say, the US doesn't exactly have a monopoly on the tech anymore, and some devices are capable of receiving a variety of signals.
Not everything the military uses if solely for killing. There are thousands of uses of in credibly accurate GPS out there. In the near future you might learn what some of those are.
It ended up in a remote fishing village in Iceland, then it drove around Croatia for a couple days. Finally, it was stranded in Death Valley and over-heated.
Sorry. Couldn't resist. See later story.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Cell tower based navigation is correct to the rough position based on relative signal strengths of the connected tower. In dense areas this could put you within a city block. In sparsely populated areas ... well lets just say when I go camping on Moreton Island and climb the hill Google maps tells me I'm 25km away on the mainland where the nearest tower is.
Wifi puts you roughly within 30-50m.
Neither is anywhere near as accurate as GPS.
Screen usage doesn't hurt, but its the GPS using power. Generally screen is the most expensive use of power when turned on, but GPS is in the top 4.
I still have more fans than freaks. WTF is wrong with you people?
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.
Now for a trick, turn the navigation on and TURN OFF THE SCREEN. Just use voice based navigation.
GPS uses a lot of juice compared to many things on a phone but it is far from the biggest consumer in a navigation session which is easily 75% the fact that the screen is on permanently.
Google Maps has a feature where, when your battery gets low, it will ask if you want to dim the screen except when coming up to turns. I'd love the option to enable that behavior full time. Just going back to the home screen is a decent second choice, I suppose.
Nope, no sig
Amazon drone delivery service.
Suborbital [spaceflight] is the special olympics of spaceflight. - Rei
even in the late 90s, early 2000s, the cell tower triangulation allowed for 3-5 metre accuracy in cities. i don't remember if it was gsm 900 or whether it needed a 2G network (1800MHz) but that was what police in europe often used to bust criminals.
hence the popularity of nokia 6110, 6150, 6210 a 7110 among criminals where the "net monitor" part of menu could be activated. here you'd select association with a single BTS (by selecting a "bts test") and that was the end of triangulation. all the police would have was that you're somewhere inside a 10km diameter.
Does RTK allow to get this resolution on realtime from a fast moving object, like fighter or missile ?
Japan has been pioneering this technology. Civilian receivers with extra hardware can get resolution down to 5cm. They are using it for things like automated snow ploughs that can follow the side of the road perfectly. Obviously when the road is solid white you can't use optical tracking. For vehicle navigation they can also tell what lane the car is in, to improve directions given to the driver.
It's also useful for surveys. Sure, you can get centimetre accuracy with current tech, but it takes a long time. With the new Japanese system you get an instant super accurate fix.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Which constellation of satellites are they using?
Can you point to what hardware it is that they are making, it should work in the US or elsewhere, and if it does, then I'm surprised I haven't seen it. I'd order some tomorrow if what you are saying is accurate.
You may be surprised how many businesses and industries rely on GPS measurements and really do need this kind of accurate location data. GPS is an infrastructure investment, just like roads, internet, public water systems, electric grid, etc., that increase the productivity of countless industries and people. The average person using their cell phone GPS probably won't notice much change, but the average person doesn't notice most of the infrastructure around them that keeps their world humming along.
Keep in mind too that one meter accuracy with a handheld GPS* may sound great, but that's only under optimal conditions when there are no tall structures, tree canopies, or thick clouds blocking signals, and enough satellites orbiting overhead in positions to triangulate from. "Real world" accuracy in poor conditions can be +/-20 feet, or more if collecting data on the move.
*- There is secondary GPS equipment and post-processing corrections that can greatly improve the accuracy of handheld GPS, but it's very expensive, so most people muddle along with just a single handheld unit.
Yes. https://en.m.wikipedia.org/wik...
Long range missiles also use accelerometers that on their own they can give target accuracy within several meter over a distance of several hundred km, as long as they have an accurate starting position.
Quality is an issue. Some phones will claim to know your location with only a single tower in range. It's very hard to use triangulation with a single tower.
Yes. https://en.m.wikipedia.org/wik...
I LOL'd, "...the system is controlled using a Xbox 360 video game controller"