Ask MetaFilter questions tagged with gps

Accurate running pace?

smackfu — Thu, 09 May 2013 06:39:40 -0800

I've recently taken up jogging again, this time with an iPhone and the Nike+ app to track my runs. It seems to be pretty sloppy at tracking pace, compared to my old Nike shoe sensor. It's very smoothed out, so doing intervals, for instance, looks like a sine wave instead of a square wave. Are there any solutions that are better at this?

Can new technology help me map my underwater fieldsite?

seachange — Mon, 29 Apr 2013 11:47:57 -0800

I need to make relatively precise measurements, to the nearest half meter, of locations on my field site, which is on the floor of a Mediterranean cove (not more than 10m deep). One possibility is to swim on the surface above my locations and use a GPS to record the points - but so far my older-model GPS's have not been accurate enough for this. I'm leaving in about a week, and just recently I was reminded that technology may have advanced to meet my needs, even since last year! Can anyone update me on the latest and greatest (waterproof) mapping instruments out there?

iPhone App Satellite GPS view

bright77blue — Mon, 29 Apr 2013 10:19:29 -0800

Hi Everyone I would like to see a list of all the GPS and Glosnass that my iPhone 5 is receiving with their signal strength. I have searched but cannot find. (This is similar to a app on the Garmin GPS) Thanks BB

Need help in understanding latitude, longitude, and GPS

bfootdav — Tue, 23 Apr 2013 13:48:06 -0800

I'm working on a new piece of music and need to understand a little better how longitude, latitude, and GPS works. Specifically with regard to the resolution and what can be reasonably expected from current technology. I do not have a GPS capable device. If I did then I might not need as much help with this. So here goes. From what I've been able to figure out the resolution for GPS is like 3 meters, but with certain augmentation techniques this can be tightened up a lot, down to centimeters even. How common is this type of augmentation to average people? What I mean is that if the average person were to go outside and use their smart phone to figure out their geographical coordinates would most people be stuck at 3 meters or might it be 1 meter, less, more? Related, if two people were to stand within 1 meter of each other how likely would it be that they would generate the exact same coordinates?

Also, what about elevation? Is that information normally available? Or let's say someone get's the basic information about the spot they've chosen, would they then be able to go online and figure out the elevation or maybe even narrow down their specific coordinates?

And then how standardized is all this information? I would like to think that every device would generate the exact same kind of information using the same standards but are there idiosyncrasies that might require conversions in order to get all the data to "look the same"? Is it possible to automate that?

GPS: Common knowledge?

Vampire Cat — Wed, 10 Apr 2013 08:23:53 -0800

Are there any published studies / figures about what percentage of smartphone users know what GPS is (i.e., do smartphone users know GPS determines your precise location)? Bonus question: do they know it's a battery drainer? I'm looking specifically for actual data, not anecdata. I need to back up my position to skeptical coworkers. I work at a small software shop making a GPS-using app, and we're having some debate about what people know.

What is the best way to track and share walking routes on an iPhone?

enn — Sun, 17 Mar 2013 10:27:44 -0800

For a personal project, I'd like to be able to track my route as I'm walking using my iPhone and then share that route in some form that can be embedded in a blog post. I see there is an app called 'MapMyWalk' that does something like this, but it seems to require a subscription fee. I don't mind paying a one-off fee for an app but I'd like to not have to worry about paying in perpetuity to keep the shared routes embeddable. (I also don't mind installing software on my own server.)

I'm not wedded to having one app that does everything—if the best approach is to track my route with an app and then export it into a file that I can load into some other software on my desktop or on a server, that is fine.

In their embedded form, I'd be ok with the routes being presented either as maps or as lists of directions. (All of these routes will follow streets and alleys in developed areas, no trails or woods.)

The ability to annotate specific points along the route with comments or photos would be nice but not necessary.

Features I don't care about: anything to do with fitness, tracking calories, telling me my total distances or speed or changes in elevation.

iPhone GPS software

HuronBob — Mon, 04 Mar 2013 15:55:47 -0800

Since I'm semiretired now, I've offered to help our local land conservancy plan, map, and develop a new preserve just a mile from my home. One of the tasks will be to map all existing trails and roads on the property. The staff at the conservancy asked that they receive the files in a GPX format. Soooo... I'm looking for an iPhone GPS app (I'm using a 4s running 6.1.2) that will allow me to: Map a hike, indicate and name multiple waypoints, and export the hike as a GPX file. It would also be great if I could attach geotagged photos within the app. Any suggestions? And, if anyone has any experience with this type of activity, is there any function that I'm not thinking of that would be useful? Thanks much!

Lost in Death Valley

essexjan — Thu, 28 Feb 2013 16:21:27 -0800

Driving from Vegas to Death Valley and back on a day trip. GPS or no GPS? We'll follow one of these routes (.pdf) but as we're both city dwellers unused to driving in huge wide open spaces, I'm concerned that missing a turning might lead us to be hopelessly lost in a pretty unhospitable atmosphere.

Is paying extra to rent a car with GPS worthwhile, given that, if we get lost, we might be seriously lost in a desert miles from the nearest town? Or are the roads so clearly signposted that it's hard to get lost.

Dense topographic data for a lot.

cmoj — Fri, 18 Jan 2013 12:41:12 -0800

I've got Home Designer Architectural 2014 and a desire to buil a house on a steep hillside. I need topographic data for this. In this program, I can import data about the topography of a lot in the form of a .gpx file. Google Earth can export a map of pins (but not a shape) to a data file that can be converted to .gpx, but placing those pins manually at a useful density would take forever and I'm not sure that Earth has sufficient elevation resolution.

So where can I get this data? Are there USGS maps with high enough resolution? An app that can plot X, Y, and Z coordinates while I walk around the lot?

Ideally I'd like everything to be accurate to within a foot, but I'll take the best I can get.

Discontinued Garmin GPS unit

alasdefuego — Sat, 05 Jan 2013 12:53:23 -0800

Is there a current production Garmin GPS unit that is equivalent to the discontinued nuvi 265WT in terms of price and features?

Help choosing a car GPS system

justlooking — Sun, 02 Dec 2012 16:06:59 -0800

We have been thinking of buying a GPS for our car; but been having a surprisingly difficult time making up our mind (at this point primarily between the Garmin nuvi 50LM GPS navigator and the pricier Garmin nüvi 1450LMT 5-Inch Portable GPS Navigator). Would love to have your recommendations/suggestions if you have used either one of them (or a similar product). Based on online reviews, Garmin seems to have the best vehicular GPS product (True?). The nuvi 50LM model appears to have most of the features we wanted (except traffic) and the right price point.

The questions that I am wrestling with:

- Firstly of course - Is this the right model to go for? (if all I am looking for is an accurate GPS with good audio quality)
- Some online reviewers seem to have had trouble updating for maps in this model. Do you know anything about that?
- 1450 LMT seem to be a more advanced and robust product. Are the bells and whistles worth spending $80 more or am I simply buying traffic updates and adv. at that price?
- Talking of traffic updates - are they worth it? It seems to require agreement to watch adv. whenever the car is not moving. If you have this (or a similar) model - do you find the adv. intrusive (say at traffic signals) or do you over time learn to ignore them (like with most web adv. for example)?

Would very much appreciate any recommendation/suggestion if you have any insight in this area.

Take My Privacy, Please!

Apropos of Something — Fri, 23 Nov 2012 10:44:03 -0800

I'm trying to hack together an OS X script that's dependent upon my location. Problem is, Apple's location services doesn't know where my home router is - and I don't have an iOS device to tell it. Is there any way I can suggest or hint to the server where my IP is located?

Iphone Offline Maps

raphael19 — Thu, 22 Nov 2012 09:01:49 -0800

Iphone Application with Offline Maps I am seeking an Iphone application that has world maps already present in its cache. That way I can use the Iphone without Internet connectivity but only with GPS function. This app *has* to work with specifying places with their coordinates (lat, lon).

Free is better but I may be inclined to pay for this app if it is way better than its competitors.

difference between GPS on a smartphone and a stand alone unit?

waylaid — Tue, 04 Sep 2012 06:39:24 -0800

What is the difference between GPS on your phone and GPS on a stand alone unit? I inheirited a stand-alone GPS unit (pretty basic) from a friend and I'm curious about the difference between this (which has a battery life that is much longer, and I could definetly see a reason for using it), and a standard smartphone with GPS. For instance, often I can't use the GPS on my smartphone without data turned on as well. Is this so the maps can be downloaded? What would I need to do to be able to have my smartphone's GPS working when I am abroad without data roaming?

(I feel like this is a dumb question, so thanks for humoring me!)

Help me build a DIY UAV to make small DEMs!

dialetheia — Wed, 29 Aug 2012 21:47:46 -0800

I want to put together an unmanned aerial vehicle for capturing aerial photos over a small area (probably <1 km2). Ultimately, I would like to be able to extract a digital elevation model from those photos. How can I get started? I have read a bunch of stuff over at DIY Drones but I still need some help putting it all together. I know a lot about GIS analysis but not as much as I'd like about remote sensing. I want to build a relatively cheap UAV, but I'm not sure what kind of firepower will be required to get the kind of resolution I need. I need the photos & georeferencing to be good enough to use an image processing service or program (e.g. Drone Mapper) to generate a DEM from overlapping aerial orthophotography that I collect with the UAV.

What is the cheapest way I could do this and still end up with a usable product with high enough resolution to (for example) generate 2 foot contour lines from my DEM?

Interesting reusable GPX logs?

sodium lights the horizon — Thu, 09 Aug 2012 23:54:54 -0800

Where can I get hold of an interesting GPX export I can use for testing some code and (maybe) showing the results on my personal website? I'm playing with some code that makes pretty pictures and graphs from GPX files. It's nothing new or exciting, but I'm using it to teach myself about some new libraries I'm interested in and would like to show the results on my website.

The problem is that I live in East Anglia, where the roads are largely flat and level or easy 30/60/70 speed limits.

I'd really like to get my hands on a PGX trail of someone driving a car round a looping (or at least, with significant long/lat changes) path with decent speed and altitude changes. The ideal would probably be something like the Nurburgring / Leguna Seca / etc or a road trip that included slow roads, motorway and some good twisty bits.

Does anyone know where I can get hold of such a GPX log that I can use for building upon (so CC or similar)?

Snail trails on Garmin Nuvi 255W

lungtaworld — Mon, 06 Aug 2012 15:55:54 -0800

Snail trails on Garmin Nuvi 255W. When out and about this device is now making pale blue 'snail trails' on the map tracking the car from A to B. It is working as it should otherwise. Does this mean that the device is on its way out? I checked some forums but could find any mention of this bizarre behavior.

find my art via GPS

diode — Sun, 05 Aug 2012 09:58:27 -0800

Hi mefites, I'm researching for an art project that needs a robust GPS unit they can put in a project that will be mobile around a few mile area. The GPS needs to be fairly robust in terms of ability to withstand shakes and jounces, being upside down or turned and twisted. We're not talking bouncing it like a basketball but rather the unit will be in a larger package moving about and being shifted around a lot. We need to be able to find the unit via GPS for a 24 hours run time. Actually, the run time needs to be at least 12 hours but using 24 hours as a way to give some leeway. When I say GPS, really it's a GPS plus the ability to signal someone where it is located. It seems to me like a cell phone would qualify for this. What are some of the options? Robust, power miser, and locatable in a 5 mile wide area. That's about it. Thanks for any tips on this.

A Device for Every Snowflake!

broadway bill — Mon, 23 Jul 2012 13:24:32 -0800

I need a new cellphone/GPS setup. Did I mention that I am also the most special snowflake in the world? In about a week, I will be moving to a rural area. The primary reason for the move is for school/work, but I'm excited about living in the middle of nowhere again, and I want to take advantage of it by drastically reducing my involvement with my cellphone. Cutting the cord(less), so to speak.

So. Currently, I have an older and beat up Samsung Galaxy S (the first gen of Galaxy phones sold in the US, I think). I use it as a phone, texting device, email thing, (occasional) GPS, and MP3 player. I have a plan with T Mobile that gives me what amounts to unlimited usage (I think it's actually 300 anytime minutes, free calling to my selected "5 Faves," and unlimited data and text, but I've never come close to using up the 300 monthly minutes), and I pay right around $100 a month.

Here's the snowflake parts:

I don't want to be glued to my phone anymore. Ideally, I will end up with a super-basic phone that I can use for outgoing emergency calls and whatnot, occasional texting, and reading email. I don't use google email at all anymore, and I sort of have grown to loathe google in general, so I don't want another android device. I'd like functional GPS on my phone, but I don't absolutely need it. I don't browse the web on my phone (at least I'm trying not to, going forward). I'd like an MP3 player on it, but that's not a must-have either. I also don't use or buy Apple stuff, so an older iphone is out.

Ideally, I want something like this: a phone with the ability to receive email from assorted services (exchange, POP3, whatever), play MP3s, and make calls/texts. I'd love it if I could get this without a contract, and for a relatively low monthly fee.

Is there a device and service for me?

Or, should I just buy a no-contract dumbphone and use a month-to-month provider like Virgin?

If I do that, is it possible to continue to use my Galaxy--no service plan, just wifi--as an email reader? I like that idea, because then I can still have it as an MP3 player, camera, email device, etc. without having it as my phone.

Can I axe my current gmail account and continue to use the android device, or will I need to either a.) keep the current gmail or b.) register a bogus gmail just to make the device usable?

My contract with tmobile is up, by the way, so walking away from them is no issue.

Does this make sense, or am I asking for something that just does not make sense/exist?

Thanks mefi!

Early examples of GPS-type things in movies/TV?

theatro — Mon, 23 Jul 2012 09:42:18 -0800

A researcher at my workplace has asked for help finding examples of his topic, early examples of "GIS (Geographic Information Systems) or GPS (Global Positioning Systems) technologies in film and TV", "examples of early precursors to map related technologies". I found someone else's Ask from earlier this year that hits on some likely ones, but he's on the lookout for older and more diverse instances if you can think of any. More details and examples below the fold! I've already pointed him to this Ask from April, which has examples of War Rooms, Situation Rooms, and The Big Board (including a link to TV Tropes, reader beware).

He could use more examples, though, especially older ones, and going beyond The Big Board. For instance, he mentions that Goldfinger has a "back-lit, moving map in 007’s Aston Martin which is very similar to most in-car GPS devices."

I'll paste an exact quote of his wording below, in case it triggers any thoughts. But my short version would be: Can you think of instances where an early film or TV show uses a device or technique that resembles a primitive version of GIS or GPS tech we use today?

His wording, which he asked me to ask you: "I am working on a paper/presentation that deals with the historical evolution of GIS (Geographic Information Systems) or GPS (Global Positioning Systems)technologies in film and TV. Specifically, I am interested in examples of early precursors to map related technologies that are now common. For example, early police shows have crime locations marked as pins on a map, today there are electronic maps with a multitude of different information associated with each point. Another example would be the James Bond film Goldfinger which has a back-lit, moving map in 007’s Aston Martin which is very similar to most in-car GPS devices. I was wondering if the community had other examples from films/TV that they recall early examples of what are now standard modern mapping or GPS devices. Thank you in advance for any assistance."

Does the latest iPad require a cellular subscription in order to use its GPS for location services?

Auden — Fri, 13 Jul 2012 14:12:56 -0800

Does the latest iPad require a cellular subscription in order to use its GPS for location services? (oh, and any reason to select AT&T over Verizon, or vice-versa?) I've been given a wi-fi only iPad ("iPad 3") as a gift, and I'm considering exchanging it for a 4G LTE version. The 4G version has a GPS chip, the wi-fi only does not.

The main reason I'd like to upgrade is the possibility of using the GPS location fuctions offline (without a cellular data plan), so I might use it with map apps, etc, without requiring a data connection to Apple or Google.

I don't want to have a cellular data plan in general; I plan on primarily using the wi-fi connection only (although I would like the option if needed). Mainly, I want to have the precision of the GPS location services instead of the inferior wi-fi location functions.

I've found several websites (for example, here) stating that I don't need a cellular subscription in order for the GPS to work (although the iPad will initially obtain satellite location information by pinging cell towers). However, the Apple employees I've spoken to over the phone have insisted that this isn't the case (one confirming his views with an in-store tech while I waited). Both have told me that I'd need a cellular subscription ("otherwise it's just like having a wi-fi only tablet").

Does anyone know the correct answer?

Finally, I don't have cell phone on either AT&T or Verizon's network. Is there one 4G network version to favor over the other? (I'm in PDX, local coverage should be fine for both and I don't travel much at the moment).

Looking for iOS app to broadcast my location

nitsuj — Sat, 30 Jun 2012 07:50:47 -0800

I'm looking for an iOS app that will broadcast my current location to a page with an embedded map, so that I can share the URL with family and friends as I travel across the country. Ideally the friends and family don't need to sign up for some other service just to view my location/progress. (I'm not concerned about security.) And they definitely shouldn't need to have another iOS app to see where I'm at (ala Find My Friends).

This app should also be able to run in the background; I don't want to have to keep it actively open at all times to continue updating.

Extra bonus points for a feature that would let me snap photos along the way and pin them to various spots along the route.

Converting GPS data to distance-time data

alby — Thu, 14 Jun 2012 12:02:49 -0800

I have some .GPX/.CSV MyTracks GPS files that I would like to use to create distance-time graphs. I can do this using GPS Visualizer but this creates the graphs for me and what I want is the raw data. Is there a website, program or script (Linux or Windows) that will allow me to do this? Taking the .CSV files as an example, I would like to go from:

"Segment","Point","Latitude (deg)","Longitude (deg)","Altitude (m)","Bearing (deg)","Accuracy (m)","Speed (m/s)","Time","Power (W)","Cadence (rpm)","Heart rate (bpm)","Battery level (%)"

to:
"Time","Distance"

An an example, one line of data looks like this:
"1","1","52.36733","-1.220571","154.0","127.6171875","32","35.75","2012-06-14T15:26:01.000Z",,,,

Help me track myself, or: 23.2% chance of the East Village

suedehead — Sun, 15 Apr 2012 23:57:10 -0800

How can I write an algorithm that predicts my future location? I'm working on a project that involves tracking my location with OpenPaths, and creating a website displaying a map of probable locations that I would be at the current point in time, based on two factors: the time of day and day of week.

So, if you accessed the website at 4:52pm on a Tuesday, the website would calculate according to historical location data, the probability that I'm at X, Y, and Z locations at 4:52pm on Tuesday. This information would be shown on a map with vague fuzzy locations, so the point is not so much that the user knows exactly where I am, but that he/she gets a vague sense of where I might be. This is a screenshot of a prototype website, built with a mix of php and python, in which gradients are overlaid onto a Google Maps-driven site.

I have everything working except for the actual algorithm. Currently the website just grabs data from a similar timeframe, and privileges the data if it happens to lie on the same day of the week. So if I've been somewhere at 5:10pm on a previous Tuesday, it'll display that moment with a higher opacity than a 4:52pm location point on a previous Saturday, for example. But this algorithm leads to certain inaccuracies -- for example, my schedule depends on the specific day of the week, but I can't just look at weekday data, since I also follow cycles of day/night that are similar across all spectrums.

I'm trying to implement a better, 'real' algorithm. Would anyone happen to have any ideas for an effective and relatively accurate algorithm to thus predict my location based on historical data? I'm not interested in hyper-accuracy, since I'm trying to obfuscate my specific location anyways, just a kind of proof-of-concept workability.

Location-prediction algorithms seem to result in a slew of massively complex algorithms. Some simple machine learning/markov model/decision tree would be interesting, I think, but I'm not sure how to apply location (gps coords), day of week, and time as two different variables and one output. I've looked at the Google Prediction API, which is perfect, except that it can only deal with one result, not two (lat & long coordinates). Something even more simple would suffice. Any ideas? Thanks!

How to print exif gps data on a photo?

gofargogo — Thu, 05 Apr 2012 10:58:46 -0800

How do I print gps data pulled from EXIF data on a series of photos? I have about 65 photos that have GPS location data as part of the EXIF data. I'd like to a) print that data on the photo (like some cameras used to datestamp images) and b) print a map showing where the photos were taken. I'm on a mac, and have iphoto, lightroom 3&4 or CS5 to work with. I've done a lot of googling and can't figure out how to automate this process. Watermarking in LR doesn't seem to allow for variables, neither the map module in LR4 nor the locations module iPhoto allow for overlaying the data on the photos or printing the map that it displays.