NAVSOP Navigation System Rivals GPS 135
dangle writes "BAE Systems has developed a positioning solution that it claims will work even when GPS is unavailable. Its strategy is to use the collection of radio frequency signals from TV, radio and cellphone masts, even WiFi routers, to deduce a position. BAE's answer is dubbed Navigation via Signals of Opportunity (NAVSOP). It interrogates the airwaves for the ID and signal strength of local digital TV and radio signals, plus air traffic control radars, with finer grained adjustments coming from cellphone masts and WiFi routers. In any given area, the TV, radio, cellphone and radar signals tend to be at constant frequencies and power levels as they are are heavily regulated — so positions could be calculated from them. "The real beauty of NAVSOP is that the infrastructure required to make it work is already in place," says a BAE spokesman — and "software defined radio" microchips that run NAVSOP routines can easily be integrated into existing satnavs. The firm believes the technology could also work in urban concrete canyons where GPS signals cannot currently reach."
What? Like assisted GPS (A-GPS)? (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 [google.com]
A-GPS is not new (http://en.wikipedia.org/wiki/Assisted_GPS), though they seem to want to extend it to other radio sources.
Made in Britain, not for the rest of the world (Score:4, 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 [google.com.au] 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.
Re:What? Like assisted GPS (A-GPS)? (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.
Almost a decade old (Score:4, 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 [prnewswire.com]
When Rosum liquidated it's assets they were bought by TruePosition: http://www.trueposition.com/technology/ [trueposition.com]
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:Doesn't sound that accurate (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.
Not new (Score:4, 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:Doesn't sound that accurate (Score:5, 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.