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Super-Accurate GPS Chips Coming to Smartphones in 2018

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Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#61

Post by gjjrfcbugxbhf »

chii wrote: post #55
MertsA wrote: post #45

Earlier quoted context omitted.

>The military has better precision, only because they buy better hardware. That's not true. Military receivers can use the Y Code which is encrypted for military use only. There are some really fancy civilian receivers out there that can leverage Y code to a limited extent without knowing the encryption key but full accuracy is only possible on a military receiver that can decrypt and use the Y code.

is there any reason to be even more accurate than a 5 meter radius? I mean, if you are targeting a person in a building, i can't see why it has to be more accurate than that. Navigation of a drone that is less than 5 meters in size may require higher accuracy, i suppose...

Mapping the boundaries of a property is usually desired to much higher precision than 5 meters!

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#62

Post by katastic »

MertsA wrote: post #45
deckar01 wrote: post #10

Earlier quoted context omitted.

Things have changed since the 90s. > In May 2000, at the direction of President Bill Clinton, the U.S. government ended its use of Selective Availability in order to make GPS more responsive to civil and commercial users worldwide. > The United States has no intent to ever use Selective Availability again. The military has better precision, only because they buy better hardware. Similar hardware is used in commercial…

>The military has better precision, only because they buy better hardware. That's not true. Military receivers can use the Y Code which is encrypted for military use only. There are some really fancy civilian receivers out there that can leverage Y code to a limited extent without knowing the encryption key but full accuracy is only possible on a military receiver that can decrypt and use the Y code.

Don't you mean... M-code? (meaning "military" code)

https://en.wikipedia.org/wiki/GPS_signals#Military_.28M-code...

Though I'm honestly surprised I've "known" of GPS for this long and never realized there were a variety of codes. Legacy--some still operating, modern, military, and more. I'm going to enjoy binge reading this wiki/math stuff tomorrow.

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#63

Post by drdrey »

colinwilson wrote: post #5

As an avid hiker and runner I'm more excited to see what this will do for things like Garmin smart watches. I run through downtown Boston a few times a week and the accuracy is very bad at times making you look like you run much farther than you do.

It also has the potential to greatly increase the accuracy of the instant pace, which is a lot more volatile than the total distance

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#64

Post by darren_ »

mikeyouse wrote: post #42
tomlock wrote: post #36

Earlier quoted context omitted.

Apple makes revenue from ad sales - Apple is therefore also an advertising company. They're the lesser of two evils. Still an evil, though.

> Apple makes revenue from ad sales Is that even true? They pulled the plug on mobile ad sales a year or two ago ( http://appleinsider.com/articles/16/01/18/after-abandoning-i... ), where else would they make advertising revenue? And in any case, a company who makes 99.9% of their revenue off of non-ad sales is definitely would never be categorized as an advertising company. My grocery store is paid to put crest at e…

The iTunes store shows ads, and they can be demographically and geographically targeted.

I don't know if they're ads or not but there's also location based app suggestions too.

disclaimer: i'm a googler so glass house throwing stones etc, and of course the scale is way different

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#65

Post by jtolmar »

semi-extrinsic wrote: post #32
colinwilson wrote: post #13

Earlier quoted context omitted.

You can see how off the trace can be here: https://i.imgur.com/eHJI8FH.jpg . You could probably do some smoothing to help fit some of this to a street but I've been on runs where I zig zag down streets just to add distance or to do hills.

Wow, that's pretty horrible, must be giving you close to twice the actual distance. I think Google Maps on my phone applies some smoothing that does this a lot better, but then it can lag for a while when I'm going sharp right in an intersection. Maybe try telling it that you're biking instead, my guess is they do more smoothing the higher speed they expect.

It's pretty much raw GPS if you're in walking or biking mode. Driving mode uses sophisticated filtering algorithms, and doesn't actually make any assumptions about your speed, though it does assume you're on a road.

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#66

Post by MertsA »

katastic wrote: post #62
MertsA wrote: post #45

Earlier quoted context omitted.

>The military has better precision, only because they buy better hardware. That's not true. Military receivers can use the Y Code which is encrypted for military use only. There are some really fancy civilian receivers out there that can leverage Y code to a limited extent without knowing the encryption key but full accuracy is only possible on a military receiver that can decrypt and use the Y code.

Don't you mean... M-code? (meaning "military" code) https://en.wikipedia.org/wiki/GPS_signals#Military_.28M-code... Though I'm honestly surprised I've "known" of GPS for this long and never realized there were a variety of codes. Legacy--some still operating, modern, military, and more. I'm going to enjoy binge reading this wiki/math stuff tomorrow.

No, I'm talking about the P code or precise code. It's modulated with the encrypted W code to create the encrypted Y code.

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#67

Post by DigitalJack »

hasperdi wrote: post #60
matt_kantor wrote: post #53

Why was "oil and gas exploration" an early adopter here? Can anyone connect the dots for me? I wouldn't expect interesting oil/gas pockets to have <5m lateral diameter, but then again I know very little about that industry.

I'm not in the oil industry. But I imagine this is a great improvement for un-anchored / thrusters positioned platforms.

I'm pretty sure this is it. They have a drill that is essentially an anchor and the rest of the platform is essentially a floating quadcopter maintaining position.

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#68

Post by gumoro »

matt_kantor wrote: post #53

Why was "oil and gas exploration" an early adopter here? Can anyone connect the dots for me? I wouldn't expect interesting oil/gas pockets to have <5m lateral diameter, but then again I know very little about that industry.

In seismic acquisition (when you acquire "pictures" of the subsurface, much before the drilling part) you need accurate positioning of your sources & sensors.

https://en.wikipedia.org/wiki/Reflection_seismology

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#69

Post by jtolmar »

colinwilson wrote: post #13
foota wrote: post #6

Earlier quoted context omitted.

You could probably trade accuracy of route position for accuracy of distance by averaging samples.

You can see how off the trace can be here: https://i.imgur.com/eHJI8FH.jpg . You could probably do some smoothing to help fit some of this to a street but I've been on runs where I zig zag down streets just to add distance or to do hills.

I've been working on GPS filtering for three years and that's bad even by my standards.

Chips with L5 should do a lot to clear that up though.

Re: Super-Accurate GPS Chips Coming to Smartphones in 2018

#70

Post by Deadolus »

lhl wrote: post #34

If anyone works in the field, I'd be interested in how this dual signal (L1/L5) chip interacts with the RTK/CPGPS [1] (which improves accuracy down to 1-3cm already (at the cost of using multiple GPS units)). RTK is commonly used in survey drones, and kits are available for about $1K. [1] https://en.wikipedia.org/wiki/Real_Time_Kinematic

RTK uses a fixed base station, ideally you know exactly where it is so that you know the exact location of your mobile unit (else you will at least get a pretty good relative position).

With the new chips, Broadcom, u-blox and others are bringing to market now you are no longer dependend on a base station to get cm-level accuracy. Instead they exploit the different properties of the L1/L5 frequencies to infer stuff about e.g. the atmosphere, as the different frequencies are altered in different ways while travelling to earth[2]. The system can thus reduce its margins of errors[1] in the position calculations. So they are not "interacting" with RTK in any way. The chips are also much cheaper than your quoted $1K price tag.

Disclosure: I work for u-blox, but not an expert in GNSS calculations

[1] https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_... [2] https://www.e-education.psu.edu/geog862/node/1715

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