NAVSOP Navigation System Rivals GPS

Doesn't sound that accurate by rossdee · 2012-07-01 14:48 · Score: 4, Insightful

If its just using signal streangth then there are going to spots in cities or other cluttered terrain where it could be innaccurate. It would be ok if there is no terrain to interfere.

Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 15:01 · Score: 2, Insightful

TFA isn't much help, but I imagine the interference in cities is exactly why this can be accurate: Each position's pattern of signals and signal strength is going to be unique.
Re:Doesn't sound that accurate by EdIII · 2012-07-01 15:17 · Score: 5, Insightful

Each position's pattern of signals and signal strength is going to be unique
Unique at that moment in time. I change the wireless in my building and the signature changes. Wireless carrier changes something on a mast and the signature changes.
This can only work if you have a DB of precise locations of wireless signals. Even assuming that is viable, it cannot replace GPS as is.
Personally, I think we need less technology to pinpoint where we are. Trading convenience for security and privacy and all that.....
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 15:19 · Score: 1

Probably uses carrier-phase correlation. When a good GPS fix is available, it can capture the carrier phases of the available 3rd-party signals, then when the GPS fix is lost, it can recover the position through correlation.
Re:Doesn't sound that accurate by jaymemaurice · 2012-07-01 16:04 · Score: 2

This can only work if you have a DB of precise locations of wireless signals. Even assuming that is viable, it cannot replace GPS as is.
But what if they program the NAVSOP to listen to 1.57542 GHz and 1.2276 GHz and send back fingerprint data of all the wireless signals to a central location in the NSA.

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Re:Doesn't sound that accurate by Jah-Wren+Ryel · 2012-07-01 16:29 · Score: 5, Insightful

Personally, I think we need less technology to pinpoint where we are. Trading convenience for security and privacy and all that.....
As a privacy and security freak I disagree. The problem is not location accuracy. It is information leakage. There are all kinds of great things I can do with my own location info. The problem is all the devices that gleefully hand over my location info to 3rd parties who wish to exploit it for their own benefit.

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When information is power, privacy is freedom.
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 16:32 · Score: 1, Informative

Its not using signal strength. Its using position. You have a set of internal antennas, that are tenths of a degree apart arrayed in a circle. You get a strongest signal from the set of elements that are orthogonal (at right angles in 3 dimensions) to the source. You can calculate based on signal strengths of two 'strongest' sets of elements the direction (accurate to perhaps 1 second of arc), the direction to one source. Then you switch frequencies and determine the location to a second source (again, accurate to 1 second of arc). Where those two points intersect is your location (really its not that different from receiving GPS signals, except the frequencies are different). You can use multiple sources to refine your position. Your initial position can be determined by perhaps the TV frequencies in use at a given locale. Since digital television broadcasts time also, you can very quickly determine the time zone. A digital magnetic compass can give you magnetic north. All of these things can be combined to help refine your location. If you have determined your city, celll tower locations can further refine your location. Its only good to within a few meters, good enough for flying bombs. Of course, any radio signal can be jammed, but how many do you want to have to jam? You had a better/cheaper solution to loss of GPS signal? At sea its not that useful, unless you could send up a balloon to say 3000 meters, at which point, you could still direction find and find your location, provided you are within about 276 km of a coastal TV transmitter. Its difficult to get higher frequencies to refract off the ionisphere, so you are then stuck receiving long range transmissions from low frequency AM/SSB radio signals. Direction finding these is difficult because of the physics involved (you need physically very large equipment, such as a Plessy "Elephants cage" such as might be used by a national governments signals intelligence agency). Clearly its not a universal solution. Its effective for aircraft, not so much for people on the ground or at sea (although dead reckoning is still used for aircraft, and even getting to within 300-400 km of a destination can give location information --further with increased altitude). We started talking about drone aircraft. For drones, this is would be a very useful method of direction finding.
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 16:39 · Score: 1

Bullshit at least to the extent that this is suppose to "rival" GPS.
Isn't GPS good to something like 3m out of the box?
From the no details that's been given, they'd be lucky to get 300m (hardly a "rival" if you are 100x less precise).
99%+ of all arbitrary "signal of opportunity" cannot yield precise distance information.
They would almost certainly want to use some kind of directional antenna. Again, hardly a "rival" if you need a vehicle to mount your contraption, and it's 100x heavier.
Guessing this is the same BAE team that last year brought you the we'll sell you a thermal display panel that you can mount to the side of your vehicle and it's going to confuse enemy thermal vision that you are a glowing mess and not worth expending their ammunition on.
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 16:50 · Score: 0

No, that's a theoretical maximum. It depends a great deal on where you are. I know back home I often times can't get a signal because I can't get a clear view of the southern sky. GPS signals going through buildings and hills tend not to be very reliable. Which is theoretically what this is suppose to help.
Re:Doesn't sound that accurate by riverat1 · 2012-07-01 17:07 · Score: 4, Insightful

Use a real GPS unit with no broadcast capabilities and you don't have that problem.
Re:Doesn't sound that accurate by evilviper · 2012-07-01 17:12 · Score: 5, Informative

This can only work if you have a DB of precise locations of wireless signals. Even assuming that is viable, it cannot replace GPS as is.
Whenever a program is looking-up the location of a smartphone, that phone is very probably also beaming back a list of all the Wifi APs in-range, their signal strength, and approximate location. Everyone who makes navigation software for smartphones is guaranteed to have such a database, and is continually keeping it up-to-date.
Not only is it practical to do this, and it has been for years and years, it's done because you're likely to get much better accuracy, and a much quicker location fix. You can prove this out by running a navigation app on a tablet that has wifi but lacks a GPS chip. You'll find that Google Maps or anything else has no problem at all pinpointing your location.
And BTW, moving one AP won't cause a problem... Triangulation requires several APs in range, and it'll try to use everything in-range to get a more precise fix so... Short of conspiring to have everyone in an area to move their APs in unison for a significant distance, you're not going to significantly fool the algorithm that handles all of this.
What's more... Before wifi was widespread, the previous fallback was a database with the GPS coordinates, altitudes, power levels, etc., of all of a telco's cell towers. It works, but not as well as the horde of prolific wifi APs these days. And for the record, I am speaking from first-hand knowledge.

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Re:Doesn't sound that accurate by ThatsMyNick · 2012-07-01 17:33 · Score: 2

If there are enough signals around you and you have enough users (who report all signals they see, so as to get their location), you can always update your database on the go (just like Google does right now).
Re:Doesn't sound that accurate by Hadlock · 2012-07-01 17:45 · Score: 1

My ye olde Blackberry Curve 8300 predated widespread GPS in phones, but was still able to fix my position in cities within 300ft or so (good enough to get "directions from my location to ____") based on signal strength from nearby towers. This is a known technology.

Granted, position on the highway is terrible (usually within 2 miles on the interstate out in the country) but as long as your mapping program can figure out which interstate you're on, it can generally give useful directions. Augmented reality apps are less useful outside of urban cores (unless you write a cow-spotting app...)

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Re:Doesn't sound that accurate by Jah-Wren+Ryel · 2012-07-01 18:23 · Score: 4, Insightful

Use a real GPS unit with no broadcast capabilities and you don't have that problem.
And you also won't have the benefit of having a computer able to access your location data either. Seriously, that's a non-answer. We easily have the ability to do the right thing. Giving up on doing anything sophisticated just because there are groups who want to abuse it too is basically the historical definition of luddism.

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When information is power, privacy is freedom.
Re:Doesn't sound that accurate by bbeans · 2012-07-01 18:46 · Score: 3, Interesting

Unique at that moment in time.
Yes. Gather an initial DB and have it "self heal" as wireless signals change.
This is precisely what Google are doing with the combination of an initial street view drive followed by an army of android phones to keep the DB up-to-date. While every android phone continues to help update the database there is a good chance it will be very accurate.
I think it's a great idea, but not very novel. Google, Apple, Microsoft have implemented this and been using it for a long time.
The downside is that to get a location you need to be online to query the database.
Re:Doesn't sound that accurate by Gordonjcp · 2012-07-01 19:04 · Score: 2

This can only work if you have a DB of precise locations of wireless signals. Even assuming that is viable, it cannot replace GPS as is.
You're right. Maybe they should make it illegal to plonk high-powered broadcast transmitters just anywhere without some sort of a licence.
Re:Doesn't sound that accurate by sjames · 2012-07-01 20:29 · Score: 2

Ever tried to use a GPS in New York City? I'm guessing that comparing hundreds of signals would tend to be more accurate and more stable than GPS in that environment even if the precision of the fix isn't as good.
Re:Doesn't sound that accurate by DarwinSurvivor · 2012-07-01 20:35 · Score: 1

Sure, pinpointing your location to a street corner isn't that hard, but consumer level GPS receivers can pinpoint you to within about 3 feet in most conditions. I doubt you can do that with signal strength measurements.
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 20:43 · Score: 0

The Luddites were chiefly in favour of setting up something like modern unemployment laws. They smashed machines in support of that goal, but in cases where mill owners were setting aside part of their profits to go to retraining of the craftsmen they'd stopped employing, the Luddites were quite happy for them to use whatever technology they wanted.
Re:Doesn't sound that accurate by nospam007 · 2012-07-01 22:04 · Score: 1

"This is precisely what Google are doing..."
You mean what the Google Streetview cars were collecting and what caused a shitstorm around the world?
Re:Doesn't sound that accurate by gnasher719 · 2012-07-01 22:39 · Score: 2

Sure, pinpointing your location to a street corner isn't that hard, but consumer level GPS receivers can pinpoint you to within about 3 feet in most conditions. I doubt you can do that with signal strength measurements.
Anyone with access to Apple's WWDC videos should watch the video about improved mapping, which demonstrates nicely how in some parts of San Francisco GPS on its own is practically worthless. From experience, there are areas in London where it's the same.
Re:Doesn't sound that accurate by vlm · 2012-07-01 23:33 · Score: 4, Interesting

Use a real GPS unit with no broadcast capabilities and you don't have that problem.
And you also won't have the benefit of having a computer able to access your location data either.
Why? Since I've done it, and its common knowledge how to do it, I'm thinking thats just wrong. Hard to believe its been over a decade since I was experimenting with ham radio APRS using a GPS, simply unplug the transmitter/set the broadcast timer to zero (or a billion) and you're done. Ever since the first NMEA output jack on a GPS in the 90s, people have been hooking them up to laptops and fooling around with big screen navigation displays (like a giant aircraft HSI, but for boats), homemade boat autopilots, automatic fishing trawling autopilots, homemade moving maps, stuff like that. The GPSD daemon has been around for I believe 18 years now, so 18 years ago it changed from a curiosity/hack to a very standardized interface. GPSD is currently maintained by ESR, you may have heard of him over the decades.
The only reason "your" computer aka cell phone broadcasts your GPS position without any control by you is because you bought into a walled garden. Its not your phone, and its not working for you.

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"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-01 23:37 · Score: 4, Insightful

All true. Right now the only "safe" GPS devices are those which have no capability of being connected to anything. It doesn't have to be that way. In-car navigation systems could be designed to not reveal your location to anybody except you. They could have a button on the dash that says "transmit my location" if you want to use the services of a central office. The car could only transmit that data itself in case of an accident, assuming of course you gave it permission in advance to do that. You could have a phone or computer app that would tell YOU where your car is instead of some central monitoring station, and YOU alone could have the ability to disable your vehicle, which would be appropriate since you'd be the only one who knows where it is.
Also, your smartphone could easily keep logs of "I told your location to X at these times during the day" and other such sensitive data like that. Everybody likes to use phone logs against people, why can't we use them FOR people for a change?
All of this is possible, but nobody seems to build it. I wonder why that is?
For now, remember that if your device can act intelligently on your location, it can and probably does do so for someone else's purposes too. If there is a microphone that you don't have a physical plug or off switch to, somebody besides you can turn it on and off. Your modern conveniences might provide some convenience for you, but they are VERY convenient for law enforcement on fishing expeditions, private investigators bribing system operators, etc.
Re:Doesn't sound that accurate by tverbeek · 2012-07-01 23:38 · Score: 2

This is essentially the system used by the original iPhone, before it had proper GPS. Using data from Skyhook Wireless about the location of wifi APs (identified by MAC), combined with the data from its phone transceiver about "visible" cell towers, it inferred the phone's position. It works, but (as shown by the fact that Apple added true GPS in the iPhone 3G) not as accurately as GPS. (I think the iPod Touch still gets by using just the wifi data, which makes it susceptible to confusion if someone with a wifi AP in their home moves to another city.) It's possible that by going broadband (in the original sense of the word) with its radio sniffing, and using all available data sources, this system might overcome the weakness of the iPhone gen1 system.

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Re:Doesn't sound that accurate by vlm · 2012-07-01 23:40 · Score: 2

You have a set of internal antennas, that are tenths of a degree apart arrayed in a circle. You get a strongest signal from the set of elements that are orthogonal (at right angles in 3 dimensions) to the source. You can calculate based on signal strengths of two 'strongest' sets of elements the direction (accurate to perhaps 1 second of arc), the direction to one source. Then you switch frequencies and determine the location to a second source (again, accurate to 1 second of arc).

From a EE/optical perspective this doesn't work. Its the same equations for lens and antennas. For a wavelength around 2.4 GHz calculate the antenna/lens size required to resolve to an arcsecond and get back to me on how to install hundreds of them inside a handheld device.
What would/could work, although not as well as you may desire, is an interferometer design, although thats also gonna have serious issues and you're not going to achieve one arcsecond resolution.
Lets just say that resolving one arcsecond at optical wavelengths in a small package is technically challenging... and the device size scales linearly with wavelength so if you wanna do a factor of a million (or whatever) lower frequency you merely have to make the device a million times larger. This is why "animals" use visual wavelengths for high res imaging, or IR for crude scalar datapoints, instead of what amounts to a biological radio telescope around 10 gigs or so, which would admittedly be pretty cool but totally impractical for anything smaller than a elephant.

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"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Re:Doesn't sound that accurate by Anderu67 · 2012-07-02 01:34 · Score: 1

Collecting SSIDs and correlating to locations is completely legal. What happened was that the cars were also (accidentally?) collecting unencrypted wifi data at the same time (and in my opinion, while this was a mistake, what expectation of privacy should you have when you don't spend the 5 seconds it takes to tick 'WPA'?)
Re:Doesn't sound that accurate by drinkypoo · 2012-07-02 01:56 · Score: 1

For a reasonable price you can EITHER have a screen and navigation OR you can have a computer interface.

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Re:Doesn't sound that accurate by lysdexia · 2012-07-02 02:04 · Score: 1

Cincinnait, OH is a real joy to navigate via GPS as well. Unfortunately for this scheme, cell and broadcast reception is often flaky. I think pretty much any city built on hills is going to be ASS HAAT. (seewhatididthere)
Re:Doesn't sound that accurate by slimjim8094 · 2012-07-02 02:23 · Score: 2

http://www.amazon.com/GlobalSat-BU-353-USB-GPS-Receiver/dp/B000PKX2KA/
There you go. $27, free shipping, spits out NMEA over a virtual serial port.

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Re:Doesn't sound that accurate by vlm · 2012-07-02 03:20 · Score: 1

I think he's asking for something more like a Garmin 72H which has a screen with navigation and a NMEA output. There's probably a cheaper one out there... You're looking at $100 or so, guess it depends on how you define "reasonable price".
This is very much like the cell phone/ipod touch situation where its dramatically cheaper to buy each separate, but if you insist on both in one case you'll have to pay a lot of extra money.

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"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-02 03:21 · Score: 0

Multipath'd!
Re:Doesn't sound that accurate by Dishevel · 2012-07-02 03:35 · Score: 3, Insightful

The same kind of privacy you can expect when you yell something out in public.
None.

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Re:Doesn't sound that accurate by drinkypoo · 2012-07-02 04:24 · Score: 1

There you go. $27, free shipping, spits out NMEA over a virtual serial port.
http://www.amazon.com/English-Grammar-Dummies-Geraldine-Woods/dp/0470546646
There you go. $12.16, free shipping if you buy something else at the same time, and it might help you understand comments in simple English.

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"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:Doesn't sound that accurate by AmberBlackCat · 2012-07-02 05:56 · Score: 1

My Galaxy Tab with OSMand did a pretty good job of tracking my location without me being connected to Wi-Fi. Of course as soon as I got home and connected, Facebook and Google probably learned everywhere I'd been that day.
Re:Doesn't sound that accurate by slimjim8094 · 2012-07-02 06:20 · Score: 1

No, I understood you, thanks. But you're asking for two things that (you've noticed!) don't line up, so if you want to have your cake and eat it too, you can take my advice and not be a dick about it. Or not, I don't really care, but it sounded like you had a problem and were more interested in a solution than pedantry.
Consumer-level satnavs aren't intended, built, or particularly suitable for connecting to a computer. A cheap dedicated Garmin GPS unit (as opposed to satnav) will do just fine in terms of locating or waypoints or connecting to a computer (I have one on a boat that works great), but it's not great at taking you through roads. They were built for trails and don't waste money, power, or size on color displays, voice synthesis, or a list of nearby gas stations. There are ones available that also do turn-by-turn, but they're substantially more expensive and won't ever work as well as a proper satnav. And it's overkill for hooking up to a computer, because they draw a lot of power the extra power draw, size, and cabling/weather problems. The $27 puck above will mag-mount to your roof, has a 5-foot cable, and is powered from the USB port you have to power anyway to use the computer.
If you insist on it being one device, you're pretty much out of luck unless you want to drop serious cash and end up with a mediocre compromise solution. But if you want computer-based geolocation capability and also road navigation, you're rather substantially better off by buying the $60-ish decent satnav and the $30 GPS receiver.
"For a reasonable price you can EITHER have a vehicle that goes over land OR a vehicle that goes over water". They're both vehicles, right? If you spend a lot of money, you can get hovercrafts that work sorta-well on each, but why shouldn't there be a cheap, good solution to both problems? It's because they're different in every way other than superficially (they both are vehicles! they both use the GPS!) and they've been optimized for their particular problem domain.

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Re:Doesn't sound that accurate by Anonymous Coward · 2012-07-02 07:13 · Score: 0

That is why I encrypt everything I yell in public with ROT26.
Re:Doesn't sound that accurate by Ramsey+Faragher · 2012-07-02 07:21 · Score: 1

Please see my detailed post on how NAVSOP works http://tech.slashdot.org/comments.pl?sid=2950387&cid=40517317 Thanks Ramsey
Re:Doesn't sound that accurate by drinkypoo · 2012-07-02 10:17 · Score: 1

No, I understood you, thanks. But you're asking for two things that (you've noticed!) don't line up, so if you want to have your cake and eat it too, you can take my advice and not be a dick about it.

You understood me, but you were just deliberately obtuse, and I'm the dick? Up yours. Go snap into your slim jim somewhere else.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:Doesn't sound that accurate by Jah-Wren+Ryel · 2012-07-02 12:21 · Score: 1

Why? Since I've done it, and its common knowledge how to do it, I'm thinking thats just wrong.

Same reason the DMCA prohibits the distribution, but not creation or use, of DRM circumvention tools. You can certainly jerry-rig something, but wide-spread adoption of it is exceptionally unlikely. When only the technical elite are capable of putting something together than its value to humanity is basically nil.

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When information is power, privacy is freedom.
Re:Doesn't sound that accurate by evilviper · 2012-07-02 16:48 · Score: 1

You are completely wrong.

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Re:Doesn't sound that accurate by RockDoctor · 2012-07-03 05:52 · Score: 1

But what if they program the NAVSOP to listen to 1.57542 GHz and 1.2276 GHz and send back fingerprint data of all the wireless signals to a central location in the NSA.
They might send such data to the NSA. But it would be degraded data and limited in scope compared to what they'd send to GCHQ, as well as being delayed.
BAE doesn't answer to the American government ; they answer to the UK government. So NSA would be away down the list of people who'd get anything out of this. 5th or 6th, I'd guess.

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Re:Doesn't sound that accurate by Occams · 2012-07-03 11:38 · Score: 1

Might be useful if you ever need to drive your guided missile frigate up Broadway, but what if you are trying to find Midway Island.

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Google does this by Anonymous Coward · 2012-07-01 14:49 · Score: 1

Google maps already does this for WiFi.

won't replace GPS by Anonymous Coward · 2012-07-01 14:51 · Score: 0

Places where GPS doesn't reach? GPS comes from outer space and reaches many places that don't have wifi, cell service, radio service, etc. If you want to navigate underground, say a subway, NAVSOP certainly has it's place - but GPS isn't going anywhere.

How do they update radiomaps to NAVSOP devices? by Anonymous Coward · 2012-07-01 14:52 · Score: 0

Article was not very clear on how the "radiomaps" are updated to NAVSOP devices. Assuming you can use SDR radios to triangulate your position, you still need to have a database of known stations / frequencies / locations. Given that there are probably over 300M Wifi accesspoints, plus probably millions of radio/TV/other stations on the planet how does this system generate and distribute this kind of "radiomap" database?

Re:How do they update radiomaps to NAVSOP devices? by vlm · 2012-07-02 00:01 · Score: 1

Article was not very clear on how the "radiomaps" are updated to NAVSOP devices. Assuming you can use SDR radios to triangulate your position, you still need to have a database of known stations / frequencies / locations. Given that there are probably over 300M Wifi accesspoints, plus probably millions of radio/TV/other stations on the planet how does this system generate and distribute this kind of "radiomap" database?
A stereotypical semi-advanced microcontroller/DSP lab exercise is building a VOR display like from an aircraft. The protocol for a VOR is simple, I don't remember exactly, but a continuously transmitting narrow beam antenna rotates continuously and transmits a 1000 hz signal and every time it flings past geographic north it transmits a precisely defined pulse of a couple cycles of 2500 hz. Or whatever. It rotates pretty freaking fast like once per second. The point being the algorithm is you play DSP games to sync up to the north and radial pulses, and the phase difference is the radial you're sitting on. Then you compare the radial you're sitting on to the radial you want to sit on, and move the needle on the VOR display. In ye olden days this was done electromechanically using what amounts to multiple PLLs but now its a couple hundred lines of DSP code.
Whats new is using a SDR to sample multiple signals. So taste all the local aviation VORs, then all the ADS-B transponder/radar signals, etc. Yes ADS-B uses a different freq range and a totally different digital protocol, but thats OK, both the radio and the decoder are all software, so just run a different subroutine... Heck use the ancient transit sats around 400 mhz if you've got the time. I haven't listened to a transit sat in probably 20 years but I bet they're still transmitting away.
There are international lists of aviation VORs... ask a real pilot or a guy who stopped at ground school like me. Or a EE who had to implement a VOR display for his DSP class. For maritime there are also interesting navigation systems. Good luck finding someone other than me who knows how to use the ancient transit sats system. On the bright side you don't need to support OMEGA since they shut that down a decade or two ago, along with LORAN (err, for decades LORAN has been "planning on shutting down in 3 years" and it always got delayed... its finally dead, right?)
The overall point being there's at least 7 broadcast navigation systems I can think of other than GPS that are fully freely documented.
This is before you start playing games like relative phase of AM and FM broadcast transmitters. Now you can not assume they're all synced up at the transmitter side, but you can assume they're at least short term stable... measure 20 signals, get 400 relative phase differences, combine with the FCC published lat/long for each transmitter, and by watching changes in relative phase you can assume the receiver is moving and the transmitters are not. Now broadcast audio is not a formal navigation system but it is fully documented. Combine "pretty good" relative movement from broadcast xmitters, with rough positioning from a zillion other services, with maybe short term inertial from accelerometers and mags, and mush it all thru the magic statistical filter, and you can get a decent position fix.
Also by correlation, a 99% accurate database can fine tune the database to perfection if a new signal appears, so it would be important to leave something like this device powered up while stationary. If you have 19 known AM radio stations, and a new one appears, its not too much of a mathematical challenge to analyze a couple hours of stationary and moving data to pinpoint the new station, at which point you've got 20 known signals, waiting to pinpoint the 21st new signal, etc. You need to start with a "decent" set of data, but you can expand that over time given enough storage and processing.

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"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger

rival? by Anonymous Coward · 2012-07-01 14:52 · Score: 0

its safe to call it.. an extension.. or a failsafe.

Isn't this already being done? by Anonymous Coward · 2012-07-01 14:53 · Score: 0

http://www.skyhookwireless.com/howitworks/

What? Like assisted GPS (A-GPS)? by Mr0bvious · 2012-07-01 14:59 · Score: 5, Interesting

Google has been using this for some time and is used on Android devices - you can see their patent here: http://www.google.com/patents/US7532158

A-GPS is not new (http://en.wikipedia.org/wiki/Assisted_GPS), though they seem to want to extend it to other radio sources.

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Re:What? Like assisted GPS (A-GPS)? by wvmarle · 2012-07-01 15:35 · Score: 5, Interesting

A-GPS still uses only GPS signals for positioning, but gets help from a data network (not necessarily mobile). Basically it receives certain orbital info of GPS satellites that are normally transmitted on the GPS signal itself. But regular GPS data is slow, it can take ten minutes or more to get all data complete. Over the network it's a fraction of a second. This often helps getting a fix much faster than with plain GPS, but the location itself is pure GPS based.
Some phones may also use the mobile network for triangulation, independent from GPS, and usually less accurate.
Re:What? Like assisted GPS (A-GPS)? by PhrostyMcByte · 2012-07-01 15:42 · Score: 1

It sounds like they're able to provide a fix without GPS, which would give it an entirely different function from AGPS.
AGPS tells a GPS receiver where satellites are supposed to be at a certain time, to help it initially lock on to their signal. It does not provide a higher-precision location, or one at all in places where GPS cannot penetrate.
Re:What? Like assisted GPS (A-GPS)? by ktappe · 2012-07-01 16:19 · Score: 1

Google has been using this for some time and is used on Android devices - you can see their patent here: http://www.google.com/patents/US7532158
A-GPS is not new (http://en.wikipedia.org/wiki/Assisted_GPS), though they seem to want to extend it to other radio sources.
iPhones have been doing this for years as well. I'll let someone else explain how Apple could be doing it if Google has a patent on it...

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"We can categorically state we have not released man-eating badgers into the area." - UK military spokesman, July 2007
Re:What? Like assisted GPS (A-GPS)? by Serious+Callers+Only · 2012-07-01 20:18 · Score: 1

AGPS tells a GPS receiver where satellites are supposed to be at a certain time, to help it initially lock on to their signal. It does not provide a higher-precision location, or one at all in places where GPS cannot penetrate.
It depends on your definition of AGPS really. In the real world, systems like iOS, skyhook, (and probably Android, not sure) do exactly what this article describes already - they use signals like cell phone masts and Wifi SSDs to work out where they are, as a separate and independent step to GPS location (though they may then use that rough location to assist GPS locating). They call this AGPS, but you can call it whatever you want. If you turn off the GPS in your iPhone, or use a wifi only iPod it will still locate you, just with not quite as much accuracy as an unobstructed GPS signal or a location generated from GPS and other signals.
Re:What? Like assisted GPS (A-GPS)? by Anonymous Coward · 2012-07-01 22:04 · Score: 0

I can set my phone to mobile networks only, and it can’t get better than 500m accuracy with it. So you can imagine how useless it is on its own.
With WIFI triangulation, I get 50m accuracy tops.
With GPS it’s about 10m.
With A-GPS it’s 3-4m.
But only WIFI works indoors.
Still the only technology that can deliver sub-cm accuracy is sticking RFID chips everywhere. And I mean all over the place. Which is pretty damn unrealistic for anything but specifically prepared places.
Re:What? Like assisted GPS (A-GPS)? by Anonymous Coward · 2012-07-01 22:32 · Score: 0

A patent. This is like using the stars, or a fixed, prominent landmark or three to do triangulation. Gee I though in WW2 this is how they
caught the radio operators. Substitute mobile phone for transmitter, and there you have it, recycle a 70 year old 'invention'.
Re:What? Like assisted GPS (A-GPS)? by Anonymous Coward · 2012-07-01 22:51 · Score: 0

In spite of all the animosity between the two, they do actually license a huge number of patents to each other. Not saying that happened here, but that is one way it could have happened.
Re:What? Like assisted GPS (A-GPS)? by Luckyo · 2012-07-01 23:51 · Score: 1

While this was originally true, it's not any more. The Assisted Global Positioning System in the modern cellular network is so accurate, it can fairly reliably replace baseline GPS inside buildings in urban areas and it has been doing so for devices that support it long ago (for example, my ancient nokia 5230 which I use for navigation has this ability).
Re:What? Like assisted GPS (A-GPS)? by vlm · 2012-07-02 00:10 · Score: 1

For a somewhat more recent example, A-GPS is more or less DGPS but over the internet instead of over a radio beacon. Yes this is yet another one of those tiresome "something people have always done ... now over the internet!" patents.
http://en.wikipedia.org/wiki/DGPS
I briefly considered becoming a surveyor around the time DGPS was "new". It was expected to replace the microwave based ranging finding systems. I have not kept up to find out how that all turned out. My impression of surveyor training was I'd fit in with the simple arithmetic and trig, but the job progression was staggeringly slow and there were about 10 applicants per position, and the paperwork related to the position was less than inspiring, so I ran from that.

--
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Re:What? Like assisted GPS (A-GPS)? by Agripa · 2012-07-02 01:03 · Score: 1

It takes more than 10 minutes to receive the entire almanac but for operation only the ephemeris for the received satellites is necessary which takes up to 30 seconds. It takes longer for PDAs and phones A-GPS because of the abysmal performance of their GPS receivers.
Re:What? Like assisted GPS (A-GPS)? by wvmarle · 2012-07-02 13:39 · Score: 1

It takes longer for PDAs and phones A-GPS because of the abysmal performance of their GPS receivers.
You say that in a pretty negative tone. I know the first iPhone created such an image (and its GPS was poor), but it's far from true these days.
My cheap-end smartphone, with A-GPS, often has a fix within seconds. Without A-GPS it surely takes longer. Accuracy overall is good. Phone GPS performance is very similar to that of dedicated GPS devices of about three years ago.

So like a TIme Domain Reflectomiter for Retards? by Anonymous Coward · 2012-07-01 15:00 · Score: 0

Measure the distance between the open short?

Relying on third party wifi inspires confidence. by nzac · 2012-07-01 15:03 · Score: 4, Insightful

Sure in an open area the signal strength from broadcast and third-party location services is fine but so is GPS.

But in an urban environment these are not accurate signal strength is only loosely proportional to inverse square of the distance so any accuracy will utterly break down. I can't see them having the money investing on getting a location DB for coverage outside major cities meaning you have to ship an unusable feature to most of the population.

The firm believes the technology could also work in urban concrete canyons where GPS signals cannot currently reach.

This will only work by regularly updating a database of local signals by driving down these roads and walking around areas. You might get the reliability for a consumer device but SDR like this can hardly be cheap, small and low power.

Possibly they have algorithm to make this manageable but i would think installing purpose built transmitting devices at every street corner would be a better option.

Problems by gman003 · 2012-07-01 15:04 · Score: 2

While it sounds like this would work decently well in cities, it probably won't have nearly as many signals to work with in less populated areas, and it would be practically useless out in, say, the middle of the Pacific. So at best, it's a complement to GPS, not a replacement.

Second, how is it going to match up different sources with physical locations? I assume they'll just have a massive database of "this wifi router is located at 31.41592N 27.18281W, this AM transmitter is at....", but that brings up even more problems. Who will maintain that database - the big regulated transmitters can probably be figured out easily, but WiFi routers? How much space will that DB take up - could make it prohibitive on some devices?

Re:Problems by Anonymous Coward · 2012-07-01 15:19 · Score: 0

Not exactly global.
Re:Problems by complete+loony · 2012-07-01 20:45 · Score: 1

The database is stored centrally. You provide information on which towers / wifi devices you can see with their signal strength. And the central database either works out your location for you, or returns the known location of each of the devices you can hear. And it will probably use the information you supply to improve the quality of the database.

--
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
Re:Problems by gman003 · 2012-07-02 00:10 · Score: 1

So what happens if you try to use it with no internet connection?
Re:Problems by Anonymous Coward · 2012-07-02 01:33 · Score: 0

presumably if you're surrounded by a horde of wireless access points you're in a part of the world where Internet access isn't difficult.
Re:Problems by Ramsey+Faragher · 2012-07-02 07:32 · Score: 1

You might want to read how it actually works :) http://tech.slashdot.org/comments.pl?sid=2950387&cid=40517317 Cheers Ramsey

Made in Britain, not for the rest of the world by mjwx · 2012-07-01 15:25 · Score: 3, Interesting

It interrogates the airwaves for the ID and signal strength of local digital TV and radio signals,

So let me drive 3 hours north of Perth, Western Australia and find that this system is as useful as an ashtray on a motorbike.

I cant really see a use for this technology that GPS doesn't already fill and a huge drawback because as soon as you get to places with only one mobile phone tower or one source of TV signals (most rural towns in Oz) its fucked (the fewer sources you have for triangulation, the less accurate the result). Then we have the great wide expanse between towns which can get up to 500 KM of open road with no TV, no mobile coverage, no WiFi networks and even AM radio is spotty at best. In fact in many places the only source of radio transmissions will be from 2 way radios mounted on trucks... if there happen to be any trucks in the area.

Really this is some nice research BAe but it has no practical use outside the lab. Seeing as it's only useful within cities any commercial product will remain inferior to traditional GPS.

--
Calling someone a "hater" only means you can not rationally rebut their argument.

Re:Made in Britain, not for the rest of the world by aXis100 · 2012-07-01 16:44 · Score: 3, Insightful

Wow, how short sighted.
They're not trying to replace GPS - it's to augment it when GPS doesnt work. If you have a receiver with both systems you are far more likely to have one of them work, because most of the obstructions for GPS also go hand in hand with the availability of other networks.
Sure it might not work in the middle of the outback, but GPS generally will so it's not the target market.
Re:Made in Britain, not for the rest of the world by fuzzyfuzzyfungus · 2012-07-01 16:52 · Score: 2

Given that it was produced by BAE Systems, a company noted largely for their defense contract work(and, since their acquisition of Marconi, this includes extensive defense electronics and RF stuff), I strongly suspect that the punchline of this work (while they probably won't say no to sufficiently lucrative commercial licensing offers) is having a product offering that provides some degree of reliability for location-dependent military hardware and munitions even if GPS is jammed, knocked out, disabled by the Americans, etc.

For civilian applications, GPS(if necessary supplemented by cell tower data or Skyhook-style wifi information), depending on how far you are from civilization, works pretty well already. However, GPS signals are necessarily pretty faint and widely recognized as being of considerable strategic value. I assume that the GPS-dependent militaries of the first world all have somebody worrying full time about how far up shit creek they would be if all their fancy guidance stuff stopped working properly. If BAE has something that can sooth these...somewhat cost insensitive...customers' fears... Well, they might just have a very profitable little device on their hands...
Re:Made in Britain, not for the rest of the world by Anonymous Coward · 2012-07-01 18:14 · Score: 1

Short sighted much? The nice thing about places where there's not much RF transmitters is that there's usually bugger all in the way of people there who need to find their location. Not to mention there's also usually open sky so GPS works just fine.
Re:Made in Britain, not for the rest of the world by wonkey_monkey · 2012-07-01 18:30 · Score: 4, Insightful

So your sole criterion for something being completely useless is that it doesn't work 3 hours north of Perth? I look forward to your input when the next article on deep-sea submersibles comes along.

--
systemd is Roko's Basilisk.
Re:Made in Britain, not for the rest of the world by PolygamousRanchKid+ · 2012-07-01 18:52 · Score: 2

It interrogates the airwaves for the ID and signal strength of local digital TV and radio signals,
So let me drive 3 hours north of Perth, Western Australia and find that this system is as useful as an ashtray on a motorbike.
Now, why would you want to drive 3 hours north of Perth anyway, if there are no digital TV or radio signals there? There is no need for a navigation system to get you to a place no one wants to get to. As to finding your way to towns separated by 500KM of no TV, just follow the road. There is only one between the two. "You can't get lost, from here, to there!"
Of course, Australia already has an excellent built-in Navigation System infrastructure: Aborigines. They have been wandering the continent for 10 thousands of years, and have not gotten lost there yet. So just stop and ask one for directions if you don't know the way.

--
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
Re:Made in Britain, not for the rest of the world by Alioth · 2012-07-01 21:33 · Score: 1

SIgh.
It's not to replace GPS, it's to augment GPS where it may be unreliable, for example in concrete canyons of cities.
3 hours north of Perth is not where your GPS will be blocked by skyscrapers or briges, so GPS will be working fine.

--
Oolite: Elite-like game. For Mac, Linux and Windows
Re:Made in Britain, not for the rest of the world by Anonymous Coward · 2012-07-01 21:55 · Score: 0

... deep-sea submersibles comes along.
What? Deep-sea submersibles? How lame and useless is that? As if it ever rained enough north of Perth to fill a mudhole, let alone a deep sea. I can't see this getting any traction in the real world. Pfffft.
Re:Made in Britain, not for the rest of the world by Anonymous Coward · 2012-07-01 22:20 · Score: 0

Maybe he could make an exception and evaluate that one 3 hours west of Perth.
Re:Made in Britain, not for the rest of the world by Anonymous Coward · 2012-07-01 22:39 · Score: 0

Yes, if a nuclear EMP wipes out GPS for 1-3 hours , the others will fill the black hole, unless the nukes exploded in upper orbit in several places, in which case the TV and Radio transmitter may not be doing so well.
In which case , a sexton and the stars will rise in popularity, coupled with a $10 electronic watch. Old is new.
Re:Made in Britain, not for the rest of the world by BitZtream · 2012-07-02 13:55 · Score: 1

If your GPS signal is blocked by skyscrapers and bridges I'd really suggest you open your eyes rather than looking at the GPS. The areas you're refering to are so few and far between and so dense that you really should just put down the gadget for 10 minutes and walk the final block to your destination.

--
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
Re:Made in Britain, not for the rest of the world by wonkey_monkey · 2012-07-02 19:12 · Score: 1

Uh, yeah, thanks for over-explaining the joke for the hard-of-thinking.

--
systemd is Roko's Basilisk.

Questionable by Sandman619 · 2012-07-01 15:27 · Score: 2

Because we all know how reliable & accurate cell tower triangulation is. That's why wireless phone's all have A-GPS being built-in, because the networks accuracy was at best a few blocks, which the FCC considered unacceptable for the nation's 911 systems. WiFi systems have such a long signal reach, many miles no doubt. Radio stations always broadcast as exectky the same power, which is why somedays you can hear them much better than others. I doubt that this will be long lived

--
Cheers !

Re:Relying on third party wifi inspires confidence by wvmarle · 2012-07-01 15:39 · Score: 1

Signal strength is unreliable, as it depends on the atmosphere in between you and the transmitter. Yet you may be able to get time data (summary mentions digital signals only) and based on that calculate your distance.

In urban, in my experience, GPS signals can generally be received but are unreliable due to reflections: the GPSr assumes direct line to the satellite, not via a reflection. As a result GPS in urban areas is often off-set, or jumpy (location jumps by 20-30m in any direction)

Re:THE MARK: It's coming! by Anonymous Coward · 2012-07-01 15:47 · Score: 0

Did you shit your pants?

Re:Relying on third party wifi inspires confidence by Anonymous Coward · 2012-07-01 15:56 · Score: 1

I think it benefits the conversation to be specific between "Localization" and Simultaneous Localization and Mapping (SLAM). The first one gets easier to do as the quality of your map data improves. The wonderful thing about being alive today is cellular carriers are strapping extremely sophisticated & sensor packed data-acquisition modules to almost every person roaming this planet. These smart phones get retired on a semi-regular basis, and as a result the logistics of adding a new sensor to the family is decreasingly difficult. If you have been following the SDR Tv-Tuner debacle then you can probably picture a future where every cell phone is equipped with an SDR reciever by the mobile phone manufacturer and can on-the-fly be reflashed by the carrier to change the type of data that is being collected. CarrierIQ was juvenile. Marketing data is passe. The value that these consumers can offer as a data acquisition botnet greatly outweighs their value as walking credit cards.

It will soon be possible to map the entire planet with waterfall graph EM spectrum analyzer data based on location. It's only a question of hard-drive space to store the resulting a complete histographic dataset.

Re:Relying on third party wifi inspires confidence by nzac · 2012-07-01 16:00 · Score: 1

Signal strength is unreliable, as it depends on the atmosphere in between you and the transmitter. Yet you may be able to get time data (summary mentions digital signals only) and based on that calculate your distance.

I think its very possible to achieve this as long as the signals you rely on are line of sight. They will have smart people working on the problem.
They use digital signals as most analogue signals have large wavelengths that cannot be picked up by cell phone size antennas and they also may have broadcast IDs.
The article makes this look like a solution to a Military problem where they can maintain intelligence on broadcast sources that will be line of sight, when the enemy brakes GPS.

In urban, in my experience, GPS signals can generally be received but are unreliable due to reflections: the GPSr assumes direct line to the satellite, not via a reflection. As a result GPS in urban areas is often off-set, or jumpy (location jumps by 20-30m in any direction)

Without using third party wireless that is almost line of sight they will not be able to do much better. And any new large sign or a large truck parked out front will effect the signal strength field of the source meaning other sources have to used to realize this source should be discarded. I still think sticking a direction transmitter at every street corner is the best way to solve this.

Almost a decade old by MDMurphy · 2012-07-01 16:14 · Score: 3, Interesting

This isn't really a new concept. Rosum was doing this years ago, calling it RadioCamera. They used GPS to record a broad range of signals, including reflections, and map them out. Using that data they built a map that could be used to locate a receiver.
http://www.prnewswire.com/news-releases/trimble-and-rosum-team-to-develop-universal-positioning-technology-74497582.html

When Rosum liquidated it's assets they were bought by TruePosition: http://www.trueposition.com/technology/

One interesting challenge not mentioned in the description of BAE's system is how they create the map. GPS has relatively few satellites and they broadcast their positions which is used by a receiver to determine it's own position. Relying on other radio sources will mean having them all mapped. Either the receiver needs knowledge of all of these ( unlikely) or it gets updates for it's local area periodically over a data channel. The map is also likely to be more than just an antenna's location, but data as to how it's received based on local topography. Alternatively it could send a snapshot of what radio signals it receives and the position is actually determined back at a server and relayed back to it. Either way seems to presume a separate data connection to the receiver to either load the whole database of signals sources ( and update it ) or a continuous connection to get the local database as it goes.

Using other signals of opportunity would be a good way to augment GPS, but surely not a replacement. Not being a replacement, I'd have a hard time calling it a rival.

Re:Almost a decade old by Cinnamon+Whirl · 2012-07-01 19:59 · Score: 1

In a search and rescue situation I can imagine a team of people each with one of these devices, as well as GPS. If the devices can communicate with each other (as a mesh network) they could pinpoint location based on the different times they see the same signal. Furthermore, if the mesh eventually reaches a position where GPS is available, this signal could then be used to establish an anchor position.

Finally, and I don't know if this was covered, but presumably this system would also allow for vertical location to be found as well.
Re:Almost a decade old by anat0010 · 2012-07-01 20:29 · Score: 1

More than a decade... I saw a working demonstration of a such a system in 1992 using the fixed locations of public radio masts as triangulation points. In densely populated areas, such as Cambridge, UK, the system could resolve location to within 50cm if I remember correctly.
This is not a new idea.

Welcome Back CONELRAD, we missed ye! by evilviper · 2012-07-01 16:52 · Score: 1

Civil Defense is everybody's business. It's your business.

In case of air raid, tune your radio to AM 640 and 1240 kilocycles on your regular radio receiver for Civil Defense Instructions. CONELRAD

ALL broadcasting stations AM, FM, TV in USA/Canada must automatically immediately cease operation, by presidential order

https://upload.wikimedia.org/wikipedia/en/d/d9/Cdb_prime_cvr.jpg

https://www.youtube.com/watch?v=sAxjkMtJA6E

http://conelrad.blogspot.com/

--
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant

Re:Welcome Back CONELRAD, we missed ye! by Anonymous Coward · 2012-07-01 17:03 · Score: 0

Ironic to tune to KFBK west coast
I rather Ignore the fucks.
McGuinuse show
Tom Sullivan
Rush
Bad Kitty the Ad Whore
Bla Bla bla Stuttering guy.
F - off

Re:Relying on third party wifi inspires confidence by Anonymous Coward · 2012-07-01 16:57 · Score: 0

Relying on telcos to configure towers correctly will get you into trouble in Australia. All the towers have the same misinformation

How well would it perform by SpaghettiPattern · 2012-07-01 17:12 · Score: 1

How well would it perform at high sea?

--

I hadn't the slightest objection to his spending his time planning massacres for the bourgeoisie... (P.G. Wodehouse)

Reminds me of Kolchuga by Anonymous Coward · 2012-07-01 18:18 · Score: 0

http://en.wikipedia.org/wiki/Kolchuga_passive_sensor

5ryn

Re:Reminds me of Kolchuga by Anonymous Coward · 2012-07-01 18:53 · Score: 0

Their only similarity is that they both have radio receivers. Nothing else.

Re:Relying on third party wifi inspires confidence by mjensen · 2012-07-01 18:53 · Score: 1

I can see how they could do it, but the implications are creepy.

They could have an app or query my phone. It'd reply with my GPS position and that the signal strength to 4 towers by name/ID. Enough tags like that, they can identify the towers in 3D space and go from there.

Enough tags like that and location can be found just from tower information.

Cool! by Anonymous Coward · 2012-07-01 19:20 · Score: 0

This NAVSOP system + Raspberry PI + Quadrotor + Semtex = Autonomous Flying Bomb! On a budget!

Fun for all ages!

Re:Cool! by BlueStrat · 2012-07-01 20:16 · Score: 1

This NAVSOP system + Raspberry PI + Quadrotor + Semtex = Autonomous Flying Bomb! On a budget!
Fun for all rages!
FTFY
Strat

--
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.

Re:Relying on third party wifi inspires confidence by nzac · 2012-07-01 19:47 · Score: 1

For the general public this is for when GPS does not work. The product will require extra hardware and if they want the best results a lot of extra hardware in there mobile device. Cellphone antennas are optimized for cellphone frequencies they are not designed to pickup frequencies so it may require extra antennas on the device. This is far more complex in the real word than GPS, you would only use this where GPS does not work.

I was thinking they could detect and report unexpected changes to wireless signal fields but this is beyond complex and a massive battery and privacy problem.

The problem of determining location off no line of sight signals using strength is a problem that is never going to solvable in too many situations without so much extra data you could not consider it feasible. If you can control were the signals are then you can reduce these situations, possibly to an acceptable level.

The key word in the press release is "learn" by Anonymous Coward · 2012-07-01 20:27 · Score: 0

The system maintains the database of signals and their locations dynamically: "The new system can learn from signals that are initially unidentified to build an ever more accurate and reliable fix on its location. Even the signals from GPS jammers can be exploited by the device to aid navigation under certain conditions."

Radar too? by craigminah · 2012-07-01 21:02 · Score: 1

About a decade ago I remember talk of radar via this same technique. AFAIK that never came to fruition. Would be interesting to see NAVSOP fully implemented but it doesn't seem very accurate.

Re:Radar too? by vlm · 2012-07-02 00:23 · Score: 1

About a decade ago I remember talk of radar via this same technique. AFAIK that never came to fruition.
Talk called bistatic radar or passive radar. Oh, its deployed and in use. The 1950s DEW line had something like this if you want to get all picky. The hilarious part about this whole discussion is the company behind this press release, BAE systems, has been selling a .mil version of passive radar called CELLDAR for about a decade that uses cellphone base stations. Its not a huge conceptual jump between passive radar and passive navigation.
For a good laugh of how it works, although this example is not exactly .mil deployment ready, see:
http://www.frisnit.com/radar/
There's also a bunch of EE / physicist types doing ionospheric research using passive radar from FM or maybe it was analog TV transmissions on the west coast somewhere.
Another good term to research is OTH RADAR over the Horizon radar, and they're not talking about putting a storm chaser dish on the roof of an old Dodge Omni/Plymouth Horizon.

--
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Re:Radar too? by craigminah · 2012-07-02 04:19 · Score: 1

I remember they were testing with analog signals but like you I'm not sure if it was FM or TV. Thanks for the info...

Re:Relying on third party wifi inspires confidence by Anonymous Coward · 2012-07-01 21:57 · Score: 0

This is from BAE systems. I guess it is fine for military uses. It is accurate for planes, bombs, missiles, warships. And probably still accurate enough for tanks

Not new by Ronin+Developer · 2012-07-01 23:30 · Score: 3, Interesting

I used to work for a subsidiary of TruePosition. One of the ventures they worked with developed this technology several years ago. It used the timing differences in the TV signals to ascertain position. TP acquired interest in that it provided the ability to obtain a location in areas where GPS sucks - like downtown Manhattan or other dense cities. Using external positioning devices, this technology could also provided high accuracy positioning within buildings - including altitude.

At Zoombak, we extended the positioning technology of our device to be able to use the signal strength and radiation patterns from the various cell towers to derive a lower accuracy location when GPS is not available (you need 4 visible satellites). And, WiFi can be used for even positioning by knowing the location of WiFi routers and map the RF signal.

Re:Not new by Anonymous Coward · 2012-07-02 05:22 · Score: 0

Downtown Manhattan has very interesting things called street signs. You may have heard of them. They are literally on every street corner.

Already old by Yoda222 · 2012-07-01 23:48 · Score: 0

"BAE Systems has developed a positioning solution that it claims will work even when GPS is unavailable"

Like a sextant, some ephemeris, a good clock, a map, and a compas ? This exists since a few centuries.

Consider as a component by Anonymous Coward · 2012-07-01 23:58 · Score: 0

Right now, mobile devices are doing something...
this is an improvement on that

GPS accuracy is what, down to a foot or so?
Ok, I retrieve from whatever DB (potentially - Single post, with "Current" GPS coordinates, accuracy, and closest N signals/deviceid/directions (As many as will fit / can pick up)) - Get back, again, single post with something like (DeviceId A is at X,Y, accuracy of Z)

Pretty quickly get a decent DB, as any deviceid that moves will auto-filter itself out, the more stable become "Relatively Good" reference points, etc.
Turn off device, move to wherever, turn it on, should be able to get "Fairly" good with GPS, then (In most of US, at least) pick up at least 2 transmission sources, be able to get down to CM accuracy fairly quickly

and yes, compounding errors and all would need to be handled, but don't need too many "Good" reference points to be able to get pretty good "Device this is located here" at reasonable accuracy (Heck, could potentially allow some pinging, if I permit it on my device... Send up to 3 pings, and use the timing like a sonar signal.... Even an "Access Denied" message gives some info)

For Middle of nowhere scenarios - Same as now. Deal with GPS and it's accuracy if don't get any wifi signals, if do, can use it to refine the GPS info

What a load of drivel by SmallFurryCreature · 2012-07-02 00:08 · Score: 1

What has a GPS to do with privacy. So I know exactly where I am with a GPS, well, I think I have a right to know and since I am using a GPS, possibly even a need!

What you are probably meaning to say is that OTHERS don't have to know where I am and they can't with NAVSOP or GPS. Unless I tell them.

Now put on your tinfoil hat making sure it covers the nose and mouth.

--

MMO Quests are like orgasms:

You may solo them, I prefer them in a group.

Re:What a load of drivel by EdIII · 2012-07-02 04:09 · Score: 1

GPS has everything to do with privacy, as it is currently implemented.
Where is a standalone GPS? Pretty damn few out there right now.
The challenge with GPS is that nearly every consumer device out there we are shoving it into does not let the consumer control who gets the information. You may *think* you control it, but you really do not. Too many things ask for it, even though it is not required, and the carriers get it anyways.
You don't have to be wearing tin foil to have legitimate concerns about technology like this. Certainly not in light of recent history, and even current events in some countries.
Re:What a load of drivel by BitZtream · 2012-07-02 13:40 · Score: 1

Where is a standalone GPS? Pretty damn few out there right now.
Are your eyes closed? Every electronics store is full of them. Walmart, BestBuy, Radio Shack, Target, every store you can think of sells nav devices.
Contrary to slashdot's ignorant belief, not every person on the planet does everything on their android device. Some of us realize some devices are actually suited for their tasks rather than trying to be a one size fits all solution.

--
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
Re:What a load of drivel by EdIII · 2012-07-02 13:56 · Score: 1

Stock prices say differently.
Most consumer devices sold today, that are used for GPS, are not standalone systems.
That includes Apple, Android, OnStar, BlackBerry, Microsoft, etc. Not just Android at all. In fact, some of the *standalone* devices offer the ability to manage travel plans online.
If we just went by percentages, right now, how many devices with GPS enabled are communicating location information to 3rd party companies?

Blackouts? Isolated areas? by JSBiff · 2012-07-02 00:19 · Score: 1

I'm just thinking through this. If my phone's battery is charged, it's likely my GPS will still work in a large blackout that covers most of a metro area - navsats have their own independent power, of course.

But, in a large blackout, seems like most RF sources would probably go silent. Especially WiFi AP's (I suppose some people might have them on UPS's, but I suspect most people do not).

Radio Stations and TV's probably have emergency generators so they stay on the air in a blackout. Same for police/fire/ems (not sure if this NAVSOP uses emergency radio signals for location, but maybe could).

I wonder if you are just left with Radio, TV, Air Control Radar, Weather Radar, etc, if that is "good enough".

I also wonder how well this system would work in very isolated areas - there are parts of the Western and Southwestern US with very little in the way of people or radio transmitters - deserts, ranch country, etc. You might only pick up one or two AM radio stations if you're lucky.

Solution in search of a problem by TVmisGuided · 2012-07-02 01:14 · Score: 1

The downsides to the concept, as I see them:

1. It would require a very large and dynamic database, and that database would require updating almost every minute, as transmitters change "signatures", are switched on or off, or are interfered with by atmospheric phenomena. The storage and computational power required to do so would keep a midrange desktop machine busy almost 100% of the time.

2. Significant events that disrupt the power grid, such as the derecho in the eastern US over the weekend, would render the system useless within the affected area.

3. Propagation conditions would affect such a system even more than GPS is affected. One big CME would knock out at least half the transmitters the concept relies on, if not more.

--
All the world's an analog stage, and digital circuits play only bit parts.

How NAVSOP works - from the developer by Anonymous Coward · 2012-07-02 03:08 · Score: 5

Hi All

It's great to see this much interest in NAVigation via Signals of OPportunity. I can't reply to everyone individually and certainly can't get into huge discussions, I've scanned this thread and thought I could give you some information to help clear some of the mist.

1 - Radio positioning is certainly not new, people are discussing Rosum here, and (in a round about way) Cambridge Positioning Systems - the latter funded my PhD at Cambridge in this topic, and I've been driving developments in this field for the last 5 years. I'm not claiming to have invented multilateration or opportunistic positioning, what we have been doing at BAE is working on removing a lot of the restrictions discussed on here - for example getting rid of the need for access to a database someone else created of all the transmitter locations, or access to differential corrections from a reference receiver. A lot of the "this is not new" comments refer to differential positioning using reference receivers and having access to databases of transmitter locations (Rosum, the old Cursor positioning system from Cambridge Positioning Systems, etc). We consider those aspects to be undesirable constraints on a flexible opportunistic positioning system and don't rely on them. The system determines the transmitter locations itself, or gets by witout actually needing to locate the transmitters at all (for example our indoor positioning system does not aim to or need to locate the transmitters to function) We have developed some Simultaneous Localisation and Mapping algorithms (again not pretending to have invented the concept, just developing new algorithms building on these methods for use in opportunistic radio positioning) to aid the learning process and allow operations during GPS denial but before any transmitters have been fully calibrated via GPS, and we also exploit the fact that we are not limiting ourselves to jerry-rigging existing devices (e.g. cellphones) to do things they weren't designed for. We also look at some exotic concepts that are too computationally expensive or demanding in hardware to ever be applicable to the civilian sector, but are applicable to other sectors.

2 - We record as many metrics as we can - phase, phase rate, arrival of certain repetitve signal structure (time of arrival), signal strength, etc. We use different metrics in different environments - for example signal strength is more useful indoors to discriminate motion than outdoors. See my ION paper for more on the indoor system http://www.plansconference.org/abstract.cfm?meetingID=36&pid=51&t=C&s=1

3 - The entire concept is based around learning - the system gets better with use. When GPS is available you can start learning about the locations of the transmitters around you, their signal stabilities, start recording signal strength fingerprints, etc. Most (but not all) types of radio transmitter can be localised by our techniques. So imagine driving into a city along a motorway - you start to learn about the DAB transmitters, DVB, cellular etc available and start to localise them. Even without fully determining their location you quickly determine what driving East looks like in "radio eyes" versus driving North based on relative arrivals of repetitive timing structures within digital broadcasts, etc. So already you can handle short dropouts and freewheel through short GPS dropouts (a few minutes) using the opportunistic radio data with only a few minutes of operation. The further to go and more you have the system on, the better, and eventually you work out where all the transmitters are (short range cellular are located very quickly, long range DAB, DVB etc take more time to locate). Eventually you have enough data to confidently state where the transmitter is and it goes in the database. These signals punch into cities much better than GPS, so calibrating these sources on the way in means that you can use them during GPS dropout inside the city. The accuracy depends on a whole host of factors - typically ~10-150 metres, and

Re:How NAVSOP works - from the developer by Ramsey+Faragher · 2012-07-02 09:02 · Score: 2

So in summary - outdoors we use time-of-arrival and carrier phase measurements, with signal strength being a secondary measurement, whereas indoors signal strength measurements combined with Simultaneous Localisation ad Mapping is key to high accuracy Ramsey
Re:How NAVSOP works - from the developer by Anonymous Coward · 2012-07-06 05:14 · Score: 0

Wouldn't it have been easier and cheaper to just fund the small push 5-10 years ago to incorportate gps and loran into one unit ?
Had you ( BAE, Raytheon, etc... ) done this, Loran would have had a chance at not getting cut and you'd have an always on, wicked hard to jam nav solution.
FYIW, keep the database simple, drop off a few atomic clocks at the major DTV broadcasters and you're good.

Practical Considerations by Anonymous Coward · 2012-07-02 03:23 · Score: 0

The description sounds like it only works in areas where there is existing radio infrastructure. Since this is BAE, they're going to put this on drones with missiles. So when they start bombing areas and take out power grids, doesn't this system no longer work? On the other hand, may be this is just going to be placed on a missile, and may not need to care about infrastructure after it reaches its target.

GLONASS and Galileo by gatzke · 2012-07-02 03:52 · Score: 1

I was wondering about the advantage to using multiple constellations, since the Russians have one and the Europeans/Chinese are putting up their own.

Looks like some GPS chips are currently capable of using the Russian GLONASS. I wonder if they actually exploit that capability? I wonder if they are future ready for Galileo?

Could you put static GPS transponders inside spaces that act like stationary satellites? Might make sense in a stadium or similar.

Re:ALIENS in YOUR TUBES! Spookz Galore! by Anonymous Coward · 2012-07-02 03:57 · Score: 0

Most of us already know and suspect all of this; we just don't run around like Chicken Little screaming that the sky is falling. We just want to eat, fuck, and play sub-sims. There is nothing you can do about the manipulation of our world by the Verdants. They are sufficiently fucking things up and will soon point to what they've done and ask us, "See what you've done? You better join the IFSP before you fuckup your planet even more." Everyone will buy it, and think they are saved.

Other, more advanced races, are allowing this. Humans will be the end of the Verdants. You'll see. You need to relax. The time scales we're talking about here go well beyond the lifetimes of yourself and your children's children's children. Posting all of this shit just makes you look infantile.

LORAN by SonnyDog09 · 2012-07-02 03:58 · Score: 1

Using distance from known transmitting stations to determine your position, eh? It sounds like they just re-invented LORAN.

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Your "fair share" is NOT in my wallet.

Everything old is new again by mrex · 2012-07-02 05:11 · Score: 1

Kind of cool. This is one way that Cold War era bombers were to guide themselves to targets. It is also one reason why, during the Cold War, the US Government took such an interest in radio broadcasters, with plans in place to "randomly" black out most stations and restrict all remaining transmissions to specific Civil Defense frequencies.

WAAS? Wide Area Augmentation System by LanMan04 · 2012-07-02 05:53 · Score: 1

Are you sure you didn't mean WAAS?

I know my super-old handheld Garmin GPS (circa 2003) could receive WAAS; I can only assume that's standard on today's GPSR chips.

Quoth wikipedia:
The Wide Area Augmentation System (WAAS) is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity, and availability. Essentially, WAAS is intended to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area.

http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System

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With the first link, the chain is forged.

Problen with this: Lack of Brass markers by RobertLTux · 2012-07-02 06:01 · Score: 1

what im wondering about is if they are "crowdsourcing"the location transmitters what happens when the location of the transmitters is WRONG (or the assumption of the type of transmitter is wrong)??

there is a reason most antennas do not have one of those "locator" disks on them THEY MOVE.

(note im talking about those markers they place in locations when they do a survey to say THIS IS AT %location%)

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timing by Ungrounded+Lightning · 2012-07-02 06:37 · Score: 1

But in an urban environment these are not accurate signal strength is only loosely proportional to inverse square of the distance so any accuracy will utterly break down.

There's a bit more to it than that.

First: Inverse square falls off FAST near the transmitter. For distant transmitters, like TV stations and (rural) cellphone towers, you have the problem you describe. But for WiFi in nearby houses or other apartments in your own you can get a pretty good idea where you are just from strength.

Second: There's also timing signals.

TV stations (especially since the changeover to digital and the use of multiple synchronized transmitters sending the same signal on the same frequency) and cell towers all send fantastically accurate timing references. They are often deliberately synchronized to a common timebase, or inadvertently synchronized by referencing a common master clock (typically GPS) so they can be compared to like obtain path-distance differences between transmitters, creating loran-style hyperbolic loci. (If they aren't explicitly synchronized the database can track their current offsets by measuring and recording it - and updating as it responds to queries in its neighborhood.

In the synchronized TV signal case the distance difference on the path between different transmitters shows up as a pattern of relative signal strengths among the many carriers of the OFDM signal. You can get one loran-curve by analyzing just one station's signal.

Both TV and cellphone base station measurements can be confused somewhat by multipath reflections. On the other hand this can be small and distorted signals dropped in favor of others with better paths. Or it can even be used to get MORE information about location.

Distance to WiFI devices can be measured by actively interacting with them in various low-level ways that are a part of the standard and a legitimate thing for any other WiFi device to do.

I'm not saying that this is what the service does. But these are things it clearly COULD be doing. And they can produce an accuracy at least as good as what is claimed.

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Re:timing by nzac · 2012-07-02 11:30 · Score: 1

I now realize that the target is car mounted units that use to rely on GPS which i think is far easier. Smart phones have more things that are unknown with battery and space constraints.

TV stations (especially since the changeover to digital and the use of multiple synchronized transmitters sending the same signal on the same frequency) and cell towers all send fantastically accurate timing references.
This might get you the right street or block almost all of the time but there will still be times it can't do or gets it wrong. Path distance is hardly reliable in an urban environment for initially locating your position. Filtering the estimated position over a trip probably they probably have worked out, especially if they include an accelerometer.
Is the timing outside of the main data or would the device require a full software defined OFDM receiver?

Distance to WiFI devices can be measured by actively interacting with them in various low-level ways that are a part of the standard and a legitimate thing for any other WiFi device to do.
Is this path or actual distance? Wifi will be really accurate if the position in the DB is accurate and its line of sight.

Re:Relying on third party wifi inspires confidence by Ramsey+Faragher · 2012-07-02 07:27 · Score: 1

My post contains some information on how NAVSOP actually works, to save alot of guesswork....! http://tech.slashdot.org/comments.pl?sid=2950387&cid=40517317 Thanks Ramsey

Re:Relying on third party wifi inspires confidence by nzac · 2012-07-02 11:54 · Score: 1

I see it working in a car mounted GPS device, though it sounds like extra external sensors and large amounts of storage are required to achieve the stated accuracy along with partial GPS coverage.

But indoor or urban mapping from a smartphone does not look like its solved. Indoor mapping using only censors available to a smartphone is not the same as this works while my phone is in my pocket where my hand, briefcase or anything else is swinging past it while I am moving though doors. In areas where you can't get GPS relative positioning is only so useful, people what maps because they have not been here before.

I guess if you have a slick "handoff" algorithm to the next wifi points you could maintain the current street at the expense of killing battery life and having to have a valid starting point.

Re:Relying on third party wifi inspires confidence by dbIII · 2012-07-02 14:45 · Score: 1

Cellphone antennas are optimized for cellphone frequencies they are not designed to pickup frequencies so it may require extra antennas on the device.

It's truly amazing how many antennas are on a smartphone these days.

NAVSOP Disadvantages by Anonymous Coward · 2012-07-04 02:39 · Score: 0

This is an outstanding achievement, however one must note that when a UAV is close to a cell phone tower, because of CDMA, other towers signals may be rejected. Also, use of microwave and IMU causes errors to accumulate over time. To learn more about other navigation systems that do not require satellite navigation and the technical basics of UAVs, take the online UAV Executive Certificate Course at Unmanned Vehicle University. The course starts July 17. Visit www.uxvuniversity.com

Positioning of hyper-sonic targets by Anonymous Coward · 2012-07-06 03:05 · Score: 0

What is the state of art of the positioning technology for hyper-sonic targets, like 6 mach or 11 mach, like the ICBM in the reentry phase? Is the current technology able to assist destroy hyper-sonic targets?

Biggest Problems with this Tech by randomErr · 2012-07-06 05:05 · Score: 1

Its been talked about briefly today but the biggest issue is that the system needs an accurate database to work. That means either you have people driving around all the time getting new data OR you are constantly connecting to the internet and exchanging your position data and those around you all the time to a central network.

The other big problem is the huge database you'll have to carry around. We are talking about trillions of data points in the US alone. The only way you get around this have an always on data connection over the internet or private network and exchange only local data.

Either issue will kill this project unless the 'free wireless internet' that president Bush pushed for and Obama promised would be instituted with the 'newly' opened up TV frequencies from switching from analog to digital tv.

http://www.usatoday.com/tech/wireless/2008-12-01-free-broadband_N.htm
http://www.bigbureaucracy.com/?p=1769
http://promises.nationaljournal.com/science-technology/expand-high-speed-internet-access-in-rural-areas/

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