NOTICE: help.openstreetmap.org is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum

I am using an iPhone 5 running the latest IOS to capture GPX tracks at walking speed (foot paths). So far, I am disappointed with the results. The tracks produced don't have enough data points and/or the points don't occur frequently enough.

Either the software isn't taking enough readings, or it is smoothing the data too much.

So far I've tried: 1. GPS Tracks 2. MotionX-GPS

The software is set to maximum accuracy.

I also have OSMTrack but haven't tried it yet.

I'm willing to buy a specialized device if it's not too expensive, or borrow an Android if you think that will help.

I can imagine that the level of detail would be fine for driving around in a car, but for foot paths, it's not enough.

asked 16 Aug '14, 01:22

Buckbeak's gravatar image

Buckbeak
41225
accept rate: 0%

I have used 3 Garmins, a yellow Etrex, a Vista HCX and an Oregon 450, I have also used a Motorola Defy, Out of town they have all recorded good traces. The Oregon gets a fix within 30 seconds of putting in batteries and switching on.to see quality of my traces http://www.openstreetmap.org/user/andy%20mackey/traces and all the Garmins work as well as when new.

(02 Sep '14, 10:30) andy mackey

I have been quite happy with the free Maprika app on the iphone. I use my etrex which has a 'most often' gpx points setting and sometimes start a gpx track Maprika too and there is very little difference in the track detail so far, though the extrex is better and this may be more apparent in gps challenged terrain. I have noticed that starting a track in MotionX-gps and Maprika at the same time 'seems' to result in a better track, but I suspect this could well be nonsense and just my imagination running a bit wild.
You need to use satellite imagery in addition to the gpx tracks if possible for finer details or refining the map at a later date when suitable imagery becomes available.
Here are a couple of cycling examples (Maprika in red, etrex 30 in blue)
one two

permanent link

answered 16 Aug '14, 02:48

nevw's gravatar image

nevw
9.8k2690178
accept rate: 9%

edited 19 Aug '14, 15:08

1

My traces look similar to yours. Maybe I'm expecting too much. How much is a differential GPS? ;)

(17 Aug '14, 01:08) Buckbeak

They are expensive for quality units. Here is a recent discussion about accuracy http://forums.gpsreview.net/discussion/29136/recommendation-for-gps-positional-and-differential-accuracy

(17 Aug '14, 01:40) nevw
1

I attached the phone and garmin on the cycle handlebar and recorded simultaneous gpx tracks on the garmin etrex30, and iphone4 apps motionx-gps, gps hiker, maprika, Wx fine. I suspect the iphone apps would have need to compete for data points in this situation so not a fair comparison between against each other but generally the garmin is better, probably because of higher frequency of data points. I loaded them all in josm with a different colour, loaded osm along track and bing imagery to compare. Here are the gpx tracks https://www.dropbox.com/sh/0h0sfcggpavb1ye/AAC7OYKzGug2KplIrU5lTy5Ra

(17 Aug '14, 06:43) nevw

To get better results you will need to hold the phone out front of you and slightly above your head, especially if you are under tree cover. Otherwise your body is blocking about half the satellites that could otherwise be seen by your phone. If that isn't practical, then clip your phone to the top of your shoulder via a backpack strap; your head will still block some satellites though.

I stopped using traces created on my phone GPS some time ago because, even with the above, the accuracy isn't as good as a dedicated handheld GPS, especially one with an external amplified antenna or at least using the above procedure. But I still use the phone for general orientation while hiking; my favorite app is GPS Maps, which allows me to upload park maps I create so I can track which trails I've already covered.

permanent link

answered 01 Sep '14, 20:13

maven149's gravatar image

maven149
111
accept rate: 0%

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here

By RSS:

Answers

Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:

×255
×112
×25

question asked: 16 Aug '14, 01:22

question was seen: 5,677 times

last updated: 02 Sep '14, 10:36

NOTICE: help.openstreetmap.org is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum