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A New Technique Makes GPS Accurate To An Inch (gizmodo.com)
A team from the University of California, Riverside, has developed a technique that augments regular GPS data with on-board inertial measurements from a sensor. Actually, that's been tried before, but in the past it's required large computers to combine the two data streams, rendering it ineffective for use in cars or mobile devices. Instead what the University of California team has done is create a set of new algorithms which, it claims, reduce the complexity of the calculation by several orders of magnitude. In turn, that allows GPS systems in a mobile device to calculate position with an accuracy of just an inch.
One of the most time consuming parts of a short journey is getting the passenger doors aligned with the port-side gangways. Unlike airports, it's not the gangways that move to the plane, it's the vessel that must align with the portside. Sometimes the portside gangway can move up or down, but many times, the crew have to tie down these mini gangways with ropes when the tides and ballast tanks aren't enough. It takes several minutes of maneuvering to get the ship aligned with the dockside, sometimes even having to reverse and try again, especially in heavy swells. If they could get GPS down to several inches, combined with the sideways movement that many catamarans have, docking could be done automatically.
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Given that we can now use GPS to great accuracy. Does this mean that the US military no longer needs to encrypt the end of the GPS signal? After all, the military has always been able to use GPS for very precise location, whereas civilians had to put up with very coarse location.
I guess. first?
Couldn't the same level of 'automatic' be achieved with image recognition cameras at the doors, or other sensors to achieve the same result?
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I'm sure there will be a lot of obvious applications for this technology, but I can see robotics being a big one.
GPS hasn't been practical for robotics but with this level of accuracy, I wouldn't be surprised to many robotic applications currently being done by humans.
It would be interesting to see how the algorithm keeps its accuracy over time and distance.
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The rest of the world gets it "accurate to a centimetre".
...nobody actually uses GPS for anything life-critical requiring accuracy, because signals can be jammed/spoofed, and sometimes the calculation is off due to reflections or satellites behaving not as expected.
And by "nobody", I except the military, but nobody notices when they miss their target.
Couldn't the same level of 'automatic' be achieved with image recognition cameras at the doors, or other sensors to achieve the same result?
Why would you want to do it in a simple way?
Sig ?
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7349142
Does this mean I can be more accurate when I drive my car into a canal because the bridge that was plotted on the map was washed out? Does this make me more accurate when the routing software takes me from Atlanta to Memphis by way of Seattle?
Accurate GPS is good.
But I'd really much prefer a GPS that can work indoors, in cities with tall buildings, near hills and mountains etc.
That seems to have much more uses than getting something from a handful of inches down to fractions of an inch.
My car and phone sometimes get confused about precisely where I am and which turn-off I've taken. And in Belgium (where there are a LOT of underground roads), it barely works at all - by the time it locks on, I've had to go down another tunnel. In Central London, it can lose accuracy just at critical points. But everywhere else it's okay.
Improve the reception and time-to-first-fix. Then worry about sub-meter accuracy. Nobody really uses it for that level of accuracy anyway.
Exactly... Sharks use lasers to line up their targets, why can't boats? Infra red seems too short range and old school or alignment applications.
I wonder how the Three Letter Agencies will respond to this? Military GPS has always had access to more accurate coordinates, now anyone can have it? Someone in Maryland is shitting bricks.
"Who are in control, they are not in control of anything - they don't even control themselves!" - Glen Beck
Centimeter scale GPS is not new technology. Real-Time Kinematic (RTK) https://en.wikipedia.org/wiki/Real_Time_Kinematic provide such accuracy, but require a base-station broadcasting local corrections. These services are usually pretty pricey.
The linked article describes an improvement in reducing the computational complexity of making the RTK calculations, but does not, in itself, make GPS accurate to within an inch.
Now you won't have to hire a surveyor to find out where the edge of your property is.
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When we reference "GPS", we primarily reference the US system.
Galileo is a European civilian system, and once all 30 satellites are in orbit it will be centimeter accurate by default, with no accuracy degradation at the whim of US military.
The bad news is the US is not happy. And had threatened jamming and shooting down the satellites in time of conflict. For the US this is perpetual or course. Should be interesting as the system is scheduled to be fully operational by 2020.
In post Patriot Act America, the library books scan you.
In turn, that allows GPS systems in a mobile device to calculate position with an accuracy of just an inch.
Dick measuring goes high-tech.
It must have been something you assimilated. . . .
So can I blame Jamie Condliffe for taking an IEEE article in metric and converting to imperial?
After all, Gizmodo is a tech lite site; so you think they would want to culturally lead the way in dropping a unit of measure that no other country uses anymore.
46137
The accelerometers on the phone are usually not that good, at all. "A mobile device" yes, but that's nothing new - the sensor fusion technology is old (kalman).
Anyone that figured out what the new part is?
Way easier with just direction lasers and alignment sensors.
Why try to maneuver the huge vessel? A simple floating bridge with gangways manually controlled like they do with airbridges for the airplanes is even more simple. Given the mass and inertia of the ships, throwing a couple of thick ropes and tightening them automatically will adjust the floating bridge gangway to the ship.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
It has been known ever since GPS has existed.
The only problem was the amount of hyperbolic trigonometry it required.
And since the military level of precision has been available, down to the inch has been possible.
From a technical standpoint this is very cool. However, from a privacy/security standpoint, I am legitimately concerned that government could really misuse and abuse something like this.
They could use differential GPS for that. It has been around for decades. It means there has to be an extra transmitter near the harbor or dock (within a distance of some tens of miles) but that certainly seems doable. It's used for surveying and its accuracy is millimeters, not inches.
I used to work at a precision GPS company, on differential GPS. What they would do is have a 'base station' that would stay in a single spot, and average the position from the GPS signal for a period of time. This is because, due to atmospheric interference, the position 'wobbles'.. Once we have an average position, we use that position to come up with correctors to send to the mobile units (via radio modem usually, though other means are possible). This got us to be on par with what this article is claiming.
I wonder if they account for the 'position wobble' of atmospheric interference. I suspect its possible, as they just pick one position they've received, and use the inertial adjust for the correctors. Not much more work than we were doing.
(I didnt write any of the algorithms or anything, just shuffled data around to different devices and libraries.)
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Once GPS attains 1cm accuracy the death knell for commercial pilots will have rung. Another 20 years and this profession will be all but gone.
Standard un-augmented theoretiucal limit of accuracy of C/A L1 GPS is 15 meters. Typical accuracy is 30 Meters. Augmented accuracy (with WAAS) can get to 3 meters in theory. But in practice is 10 meters. Use of various extra redundancy maybe just might if you are very very very lucky get you to an augmented (WAAS) accuracy of 3 meters.
It is a HELL OF A LONG WAY to go from 10 feet to 1 inch. Not even decrypted L2 (Military) in-use accuracy gets anywhere near 1 inch.
I believe that ship based dead reckoning systems are physically attached to the ship and "up" for the dead reckoning system is always "up" with respect the the physical ship. Same thing for "forward" or "front" (or "fore" if you want to get all nautical). How could this work for a phone that is in some random (and changing) orientation in your pocket?
airplanes on the gruond don't move nearly as much as ships on moving water. Consequently, the gangways are massive fuckers. Not impossible, but not the best of ideas. Simpler would be smart winches dockside that would help reef it in.
Scanning Lidar will work. Map it first and run some ICP algorithms. Basically you have a GPS pose and a ICP Lidar corrected pose. Highly accurate if you can map the dock well enough.
Trimble, among others, has made and sold centimeter accurate backpack GPS units for surveying and other uses, since the 1990's. Similarly accurate GPS is available for aircraft and the U.S. government has on board missile GPS that is equally accurate.
My Galaxy S4($500) is accurate to no more than 3 meters, verified repeatedly. My boat's Garmin GPS($2,000) is accurate within two meters after a trip of 2,000 miles. Aircraft GPS from Garmin $6,000+ 1 meter accuracy. Stab you right in the eye from the other side of the planet accurate GPS is nothing new. It's decades old! But, for that level of accuracy there is a higher price, one that the consumer is unwilling to pay when such accuracy is simply not necessary, when the consumer only needs accuracy within a 20 meters.
That these guys have come up with a way to increase accuracy, presumably at the same cheap prices we're use to is great. But don't go making absurd claims about such accuracy not previously being possible in sizes small enough to fit in a car. That's been perfectly possible for decades, you just didn't want to pay for it.
I use a usb gps sensor I built around 1998 which simply measured rate of change, connected via CAN to the speedometer and power steering, considered angle travel as well as using a compass/gimble. Certainly, it wasn't real precise, but it worked quite well. I don't think I used more than two hours in matlab to code it.
As for CPU, it's a 16mhz z80 derivative... no FP.
One of the most time consuming parts of a short journey is getting the passenger doors aligned with the port-side gangways. Unlike airports, it's not the gangways that move to the plane, it's the vessel that must align with the portside. Sometimes the portside gangway can move up or down, but many times, the crew have to tie down these mini gangways with ropes when the tides and ballast tanks aren't enough. It takes several minutes of maneuvering to get the ship aligned with the dockside, sometimes even having to reverse and try again, especially in heavy swells. If they could get GPS down to several inches, combined with the sideways movement that many catamarans have, docking could be done automatically.
Maybe they'd have better luck with the starboard side.
Image recognition isn't exactly simple if you intend for it to work at more than one port.
Specific coordinates can be easily transferred when assigning a spot. Data for image recognition becomes complicated very quickly.
A product with these specifications seems to be already available on the market: MTi-G by Xsens. The technical specifications talk of a resolution of 2.5 cm, which is about an inch. It uses the kind of sensor fusion algorithms described in the article. Xsens is a Fairchild Semiconductor company, an industry icon delivering power solutions for the mobile, industrial, cloud, automotive, lighting, and computing industries. Xsens has offices in Enschede, the Netherlands and Los Angeles, California.
I never knew Juggalos were so concerned with positioning.
Thanks to the War on Drugs, it's easier to buy meth than it is to buy cold medicine!
Compute power is such today that it seems *very* likely they could just have a live video feed and a touch screen. When you're close enough to the dock to see it, you touch where it is on the screen, then just using that pattern the docking can happen automatically from there on out. Obviously there will still be potential to override it and use manual control (often via lateral thrusters). It should be trivial for something like the lasso tool to grab and recognize a gangway.
And, you know what they say, "Gangway or sickbay!" Err... Maybe you don't know what they say. Anyhow, it'd be pretty easy (I should think) to write a system that holds a temporary gangway image in storage. With a clever hack or two, they could probably even share it by database among various docking ships, the same company, or things like that - they can push it out by cellular protocols or even just radio encoded data. Then anyone will be able to use the images. Storage is cheap, they can just store that image on the device and never have to worry about it again - coupled with GPS then it might actually be possible to get rid of some of the specialist pilots who come out and tell them how to get into the bay, dock, wharf, etc... (A person comes out on a small boat, climbs up the side of the big boat, and then tells them how to avoid obstacles and whatnot - or sometimes actually does the piloting themselves.)
"So long and thanks for all the fish."
I'm still convinced the 'net could use a "smack user" button. That was horrible and you should be ashamed of yourself! Why, I ought to...
I have a niece who's into that thing. She even wears war paint and goes out to festivals and whatnot. I think they call them gatherings. I've met some of them and I've been given the title of "Honorary Juggalo." That's not exactly something I was looking forward to gaining as an accomplishment but, well... It's something and I guess it's good that they have each other.
They do seem really keen on spending gobs of money for official merchandise. There's seemingly some things that are more rare than others (or they claim it is) and they do a bunch of trading among themselves. They often sport very poorly done tattoos of a hatchet man - except they appear to be carrying a cleaver in the best of cases and an 8 bit goombah in the worst of cases.
"So long and thanks for all the fish."
Yawn, come back when it's 1cm, then I'm impressed.
I already market Sub-centimeter accurate GNSS receivers. I doubt any any math calculation alone can give you that accuracy. You need RTK (real time kinematics) ground station correction which is available now for high end GIS to correct for weather, pressure , atmospheric, and orbital variation on a consistent basis. I would belive maybe sub foot from a handheld device, but not sub inch from GPS math alone.
...25.4mm ?
This would be great if the USPTO hadn't granted a company called vectornav a patent on using solid state sensors in fusion with a GPS receiver to improve accuracy. Yes there is plenty of prior art. Yes many hobbists/universities have been doing this for long before the patent was filed. I guess we can just hope a company like apple infringes their patent and gets it invalidated. Yay for government monopolies.
Seattle had some fancy new ferries with some electronics. After destroying multiple docks the manufacturer admitted to the thought it might not be pilot error. Probably because the ferry people had,a really good shot at sending the damn ferries back and getting boocoo damages. Not to mention the really pissed off commuters who had to deal with the busted up docks and schedules. Some of those commuters could buy the ferry system.
WTF is an inch ? Who even uses this old style measurement system any more.
Does GPS really work in inches ?
That would shift the bottleneck to engine power, and the deliverability of that power. That costs serious coin for any working vessel,
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Surely this should say a precision of 1 inch (25.4mm), not accuracy? Let's not get the two mixed up!