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US GPS, EU Galileo to Work Together
saintory writes "The US and EU are in talks to allow their separate GPS systems to work together. The future uses would allow enhanced location information based on two readings, among other benefits. 'The market probably will drive dual-use receivers. We think probably that single (U.S.) GPS-specific, or Galileo-specific receivers — the market will phase out in time [...] It just doesn't make sense to limit yourself to just one system'."
Actually, citizens haven't had globally downgraded signals since May 1st, 2000. The US military found it could regionally downgrade signals to protect sensitive locations while allowing people in general to have full access to GPS.
Misguided or not, the missile shield is not intended to divide you. If you want to argue that will be an unfortunate side effect, that's one thing, but if you seriously believe that it's part of a strategy of divide-and-conquer, then I truly think you're putting motives in there that don't exist.
Now, assuming that you merely meant that it would be an unfortunate side effect, you also should realize that Poland and the Czech Republic dearly want us to put the missile shield in their countries (or at least their governments do). I'm not arguing that's a sufficient reason to do so - I'm just pointing out that we're not imposing this on them. They want it. This came out quite strongly after Putin suggested that it be put in Azerbaijan instead, if the goal was truly to protect Europe from a Middle East attack.
Ben Hocking
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That's a great argument for seven years ago, but selective availability is ancient history now.
http://www.gpsinformation.net/main/gpsspeed.htm
Defense department regulations prohibit standard consumer GPS receivers from functioning above 60,000 feet and 999mph (simultaneously). Most GPS receivers seem to set hard limits at EITHER 999mph or 60,000 feet.However, this is all a moot point. The defense department has the ability to selectively degrade the civilian signal in certain geographic regions, while leaving the military signal as well as the civilian signal outside of that area intact (and accurate).
Someone who is using an ICBM (or some other sort of long-range delivery system) is not going to be using GPS. They're going to be using a combination of radar, topographic map data/recognition systems, and inertial guidance (as to prevent navigation references to be screwed with during the cruise phase of the weapon in question).
The concept of combined receivers isn't all that unusual. There are receivers out there, primarily used in aerospace, that combine GLOSNASS and GPS to render a more accurate position.
Of your 5 satellites visible, i would be betting one of those was a WAAS, so you can only really count the 4 sats. The critical thing is the Dilution of Precision (DOP). Your accuracy on the ground is directly proportional to the DOP. Basically, (thinking two-dimensionally here for the purpose of the exercise) you can think of this value as the area of a polygon with your receiver on one point, and the gps satellites making up the other points. Having more satellites (ie. combined constellation) along the short edge of a long skinny polygon will not significantly increase the area. Same goes for your DOP. I have done some experiments with combined GPS glonass solutions, and if you are in a crummy environment like down a trench or in a built up city, the combined solution accuracy is not always better than GPS alone. That being said, having more sats in the sky DOES increase your availability of a position because you reduce your chances of losing lock on all your sats at the same time when moving through a built up environment.
I would tend to think that a GPS tracking system for cars would be land based like what ships and boats use out at sea. Doesn't require the same level of transmission gear and is pretty damned reliable. You could certainly track cars as I believe that is what onStar does here in the U.S. already. Of course I suppose nothing stops car manufacturers from putting the required gear to transmit to a satellite or five.
What are you talking about, in terms of "like what ships and boats use out at sea"?
A GPS receiver is just that -- a receiver. It doesn't transmit. Full stop.
If you want to create a position reporting system, then you need some way to get the positional data back into a network. There have been various ways of accomplishing this.
Amateur radio operators have put together a very nice network called APRS, which uses 2-meter handheld radios, coupled with standard GPS receivers and interface chips, to "ping" your position to ground stations, which then dump the data onto the Internet so you can see it.
Most commercial systems, like those used on trucks, use the cellular phone network in some capacity. (Some of them use analog modems and make voice calls, others use GPRS or CSD to avoid the voice call.) But of course this costs money -- you have to pay for the cellular connection somehow, even if you only use it a few times an hour or day. This is how OnStar works (and you pay a monthly or yearly fee for it).
In order to make a "position beacon" that would work everywhere, you'd need a backhaul that didn't depend on terrestrial infrastructure -- the logical choice would be to use the Iridium network. (A network of low-orbiting, cellular-type voice communications satellites.) I suspect this is used for sea shipping and marine navigation, if you want remote position-reporting. But Iridium equipment and airtime isn't exactly cheap.
Creating a network that could tell you the position of every car on the road, in real-time, would be a big endeavor. It's probably a lot easier just to use E-Z Pass-type RFID sensors and readers at key locations (under bridges, etc.) than to try and create a wide-area network of GPS-equipped position beacons and receivers, just because in a congested area, you'd need a base station pretty much on every lamp-post in order to provide good coverage. If every car in an area was reporting its position ever minute or so, you'd quickly saturate the available capacity of the cellular and APRS networks. RFID would be a much better choice.
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You make some interesting points, though I am not sure how they support your claim that Russia is not a European country.
_ Europe#19th_century ) it actually makes Russia fit into the European tinderbox rather nicely, wouldn't you say? I fail to see why just because Russia has occupied Poland makes it any less European; Germany has also occupied Poland, England has occupied France, Sweden has occupied Norway... what's so special about Poland?
For example, you call Russia expansionist (presumably because of the Crimea & Siberia invasions) yet you do not consider the massive Brittish, French, Spanish, and the Dutch colonies all over the World; hell, the US of A used to be a British colony, does that make the UK non-European?)
You mention some wars that evidently make Russia an outsider, yet when I look at how many conflicts there were at the time (e.g. here: http://en.wikipedia.org/wiki/List_of_conflicts_in
Additionally, your cultural origins claim is also not convincing, since Byzantine empire was the Greek part of the Roman empire IIRC and Scandinavia can be considered 'European' enough.
Overall I agree with you that Putin is not exactly the guy that inspires trust, but I would rather wait and see, or even extend the welcoming hand (like Germany did to Poland and the Baltics several years ago), instead of dismissing Russia outright.
Obama likes poor people so much, he wants to make more of them.
How old are your GPS receivers? I use headless (no display) SiRF III-based receivers that sell for under $70 and they work indoors where my older, expensive Garmin units don't, and rarely give a fix less accurate than 30 feet. And that's with the built-in patch antennas.
I think Garmin's new handheld units (the GPSmap 60CSx I'm sure of) use the SiRF III chipset. If you're going to carry a GPS receiver for backpacking, get one of those, carry a couple extra sets of lithium batteries, and you're set. I still recommend carrying topo quads and a compass, just in case. Also, bring a ruler along and make sure you understand how to plot GPS readings on the map by hand. It's really not that hard, and a 7.5" quad beats a tiny GPS display any day.
They used to degrade the C/A signal, by adding jitter to the clock and ephemeris data. This was called Selective Availability (SA) but this has been discontinued. AFAIK, by "discontinued" they mean they will not turn it back on again even in time of war. Oddly, it was actually turned OFF during the first Gulf War.