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By euant on 28/07/19 at 2:43pm

First off, thanks for this great site and resource of walks!

I have noticed a slight bug however after logging my first walk report for Seat How. When viewing the hill page I see the following text near the bottom of the page:

You walked up this hill on .

Looking at the page source, the " ." contains an empty link that links to a walk log page with no text inside the anchor element.

My recent walk report is however listed lower down on the page as the only available walk report.

Issue #2 (sorry!)

I've also noticed an issue on the walk log page which says the following above the map on the right of the page:

GPX file not found or zero size (invalid permissions?)

However, the walk report itself does show the route from the GPX file I uploaded.

Again, thanks - and sorry to be a nuisance :roll:


By TallPaul on 28/07/19 at 3:08pm

Thanks for the report. We'll investigate.


By TallPaul on 28/07/19 at 4:25pm

OK, I can see what's happened (I think): you've got a very curious GPX file there.

It contains a number of waypoints, a route1 with almost 1000(!) route points in and, more significantly for us, a track2. It's the track we would have tried to use as that's a record of where you actually walked as opposed to where you planned to walk however for some odd reason for each track point there's a location but no times or elevations (which you would normally expect on a track).

I think this has confused the software. i'll have to investigate what the software does in that situation.

Anyway it looks like the GPX might have been created by the OS app running on an iPhone. Is that right?

  1. A route describes where you are intending to go, point by point. For more information click here.
  2. A track records where you have been and when you were there. For more information click here.

By euant on 28/07/19 at 4:30pm

Yep, I'm using the OS Maps on an iPhone as I'm an OS Maps subscriber so it's the easiest way for me to record routes. I did notice it had a lot of points, but I'm not sure if there's a way to stop it tracking quite so many.


By TallPaul on 28/07/19 at 9:31pm (last edited 29/07/19 at 8:24am)

We've been discussing this and we're now not clear precisely what occurred which lead to this GPX file being created. So can you tell me:

  1. Did you plan the route1 beforehand using this app (assuming that this is possible)?

  2. Did you ask the app to record your track2 while you did the walk (assuming that this is possible)?

Thanks.

Edited to add: Ah, or did you simply download this was from OS and do the walk guided by their app. Looking at the meta data in the GPX file it looks like this is one of their walks.

  1. A route describes where you are intending to go, point by point. For more information click here.
  2. A track records where you have been and when you were there. For more information click here.

By euant on 29/07/19 at 10:15pm

I actually recorded this as I walked it. I set it off using the "record a route" function within the app, then when I'd finished walking I saved the route and made it public. I then exported the GPX from the app to iCloud Files and grabbed it from there.. The route I recorded can be seen here: https://osmaps.ordnancesurvey.co.uk/route/3723583/Seat-How-Summit-Trail-Whinlatter-Forest (I think it needs an OS Maps subscription to export, but I believe you can view it without one).

I've now exported the GPX from the OS Maps website and it looks like when exported from there it includes the elevation:

<rtept lat="54.6097000" lon="-3.2271070">
    <ele>326</ele>
&lt;/rtept&gt;

It looks like the app on the iPhone exports GPX files without elevation and with a different degree of accuracy for latitude/longitude:

&lt;wpt lat=&quot;54.609700&quot; lon=&quot;-3.227107&quot; /&gt;

Really weird!

I've uploaded both GPX files here:

The app version seems to have a bunch of extensions with text like "slight right" and stuff, which I'd guess the app uses if you then want to follow a route you've recorded.


By TallPaul on 30/07/19 at 8:18pm (last edited 31/07/19 at 9:44pm)

Oh my, where to start?

Well the first thing to say is that the OS app sucks.

Let's start with the basics. They've got a function called "record a route1"?! Well in GPS (and GPX) terms you don't record routes you record tracks so that doesn't inspire confidence.

As for the two files well the one you used on the our web site is the "App export" version and there's several things of note about that:

  1. In the meta data the file is marked as copyright "Ordnance Survey" (which seems odd given it's your content but perhaps you sign it over to them as part of their terms and conditions - it wouldn't surprise me) and the copyright year is 2015, which is just wrong given that you recorded this on 27th July 2019.

  2. In the metadata they've also recorded:

    • the start time. This is the only place where an absolute time is given - the only other times (see below) appear to be relative.

    • the total distance in metres but expressed to six decimal places, so thousandths of a millimetre (this bizarre overspecification of significant digits is a recurring theme through this file).

    • a field "os:elevation_ascent" which you might naively expect to contain the total elevation but is actually 0.000000 (again six decimal places). Whether this is because you did a loop, so your nett elevation is zero or if it's a bug I'm not sure but your actual ascent according to our software was 255m.

  3. They've taken the track2 you recorded which had 972 points in it and have included it in the GPX file but in three different formats:

    1. as a set of waypoints. I've genuinely no idea why anyone would want this. If I uploaded it to my GPS it would fill my waypoint memory with 972 unnamed waypoints (and I would be furious).

    2. as a route, again with 972 route points (which is just ludicrous, for a walk that length I'd had thought twenty would be more than enough). And then it gets weirder as, for each route point it also has a number of other fields:

      • Not "name" which is the one you might expect for a real route point, but "desc" which appears to be a text description of the direction to the next route point (so "Continue", "Slight right", etc) and must be computer generated. It's also completely unnecessary as a GPS will do that for you on the fly based on what it knows about the location of the next route point.

      • A number of fields from graphhopper including "gh:distance" which appears to be the distance in millimetres and expressed to fifteen decimal places i.e. 10-18m (bear in mind that an atom is in the order of 10-10m!) from this route point to the next one.

      • "gh:time" which appears to be the time it took you to go from this route point to the next one, expressed in milliseconds and to expressed to a paltry twelve decimal places. I'm not 100% certain about this as the total appears to be one hour, twelve minutes, which seems remarkably fast given the Naismith time but perhaps you can confirm that?

    3. as a track however the track only has the positions and not, as one might expect, the time and elevation at each point.

So they've taken a track and turned it into three entities two of which are next to useless and the last, the one you actually want, it incomplete.

The "Web export" version is largely a cut down version of the first file but containing only the route and each route point only contains position plus elevation, which was sorely lacking in the other file. There are no "desc" or "gh:" fields, for which I suppose we should be grateful.

So what does this all amount to? Well, in essence it's appallingly bad and I'm amazed Ordnance Survey, who I've always had a lot of respect for up until now, released it into the wild. It smells like it was written by sub-contractors, who had no real idea about the way GPX files are normally presented or used and had no feel for issues like accuracy.

I have a contact in OS who works with that team. I will write to them.

I will also do what I can to clean up the mess it's left with your records on our site.

Meanwhile you said you also had ViewRanger on your phone and, as we've established from later walk reports you've posted, that's doing a fine job. So I'd stick with that or a dedicated GPS for recording your track in future.

  1. A route describes where you are intending to go, point by point. For more information click here.
  2. A track records where you have been and when you were there. For more information click here.

By euant on 30/07/19 at 10:15pm

Wow, thanks for the detailed summary! I work as a software engineer myself, though not in any field related to GPS or anything so it's always nice to learn a little more about something you were previously ignorant about.

I had noticed some of the things like the copyright. As you say, it could be in the terms and conditions that you sign your life away but I can't say for sure since I did the usual "accept and continue" routine as everyone tends to do.

Regarding the time, I did actual do it in just over an hour so at least that's accurate though I've no idea why it's expressed the way that it is.

I think I will stick to ViewRanger from now on - it's just a shame that the user experience within their app is awful compared to Ordnance Survey's. I have been looking at getting a dedicated GPS for a long time, so perhaps now is the time once I work out which one is best value for money.

If you do manage to get in contact with your contact at OS, I'd be very interested to hear anything that they have to say. The app does seem to be under ongoing maintenance currently as they last released an update in February: https://apps.apple.com/gb/app/os-maps/id978307846 - interestingly their promotional pictures also talk about "recording a route" :lol:

If there's anything I can do to help clean it up (apart from never uploading another export from the OS app ;)), please let me know.


By TallPaul on 01/09/19 at 2:10pm

I have finally (sorry for the delay, being distracted) resolved these two issues.

The first is related to the business of no times in the GPX file, as discussed elsewhere in this topic, but we should have coped better, which we now do. The empty link now says "an unspecified date" ... a bit clumsy but at least it gives you a link on which to click.

The second turned out to be the code coping badly with spaces in the GPX file name. I've now tweaked it so that it handles them fine and so you should now be seeing the track1 in your walk log page.

  1. A track records where you have been and when you were there. For more information click here.

By euant on 01/09/19 at 3:45pm

Nice one, cheers for the update TallPaul!



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