GPX Track Editor for Android

[lewl...@gmail.com]

I have written a track editor that runs on Android tablets, and it is now available for beta test on the Google Play app store at:

https://play.google.com/apps/testing/com.lewlasher.trackEditor

GPX Track Editor is similar in functionality, as a first approximation, to other track editors such as GPS TrackMaker, which I have been using for years on the Windows platform, primarily to make maps of hiking and cross-country ski trails.

The main purpose of GPX Track Editor is to help the user efficiently clean up data gathered in the field. It includes tools for track reduction and averaging, and it is easy to visually assess the results of these tools before accepting the results. Tracks are layered on a Google Map display. As the name suggests, the editor reads and writes (only, currently) GPX files.

Because of my interest in mapping trail networks, the tool makes it easy to create tracks that reflect the network "topology" by including junction points in each track. For example, when reducing a track, there is an option to protect such junction points from being reduced out of existence.

Documentation for the map is contained within the app, in (hyperlinked) help messages.

Lew Lasher
Cambridge, Massachusetts

[lewl...@gmail.com]

I forgot to mention that this is a free app.

Lew Lasher
Cambridge, Massachusetts

[Terje Mathisen]

lewl...@gmail.com wrote:
> I have written a track editor that runs on Android tablets, and it is
> now available for beta test on the Google Play app store at:
>
> https://play.google.com/apps/testing/com.lewlasher.trackEditor

Great!

>
> GPX Track Editor is similar in functionality, as a first
> approximation, to other track editors such as GPS TrackMaker, which I
> have been using for years on the Windows platform, primarily to make
> maps of hiking and cross-country ski trails.
>
> The main purpose of GPX Track Editor is to help the user efficiently
> clean up data gathered in the field. It includes tools for track
> reduction and averaging, and it is easy to visually assess the
> results of these tools before accepting the results. Tracks are
> layered on a Google Map display. As the name suggests, the editor
> reads and writes (only, currently) GPX files.

I wrote track reduction/optimization code a long time ago, i.e. even
before the end of Selective Availability when track points could be up
to 100 m off, but the error was random and slowly changing.

Have you implemented track adjustment tools, i.e. a way to drag the
track through points where the map tells you that it had to pass, and
the in rubber band fashion adjust all the track points between
junction/fix points?

Terje

>
> Because of my interest in mapping trail networks, the tool makes it
> easy to create tracks that reflect the network "topology" by
> including junction points in each track. For example, when reducing
> a track, there is an option to protect such junction points from
> being reduced out of existence.
>
> Documentation for the map is contained within the app, in
> (hyperlinked) help messages.
>
> Lew Lasher Cambridge, Massachusetts
>

--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

[lewl...@gmail.com]

Terje Mathisen wrote:

> I wrote track reduction/optimization code a long time ago, i.e. even
> before the end of Selective Availability when track points could be up
> to 100 m off, but the error was random and slowly changing.

I wrote the reduction and averaging code some 10 years ago, but I did not use it a lot because it was not integrated with the track editing tools I was using.

> Have you implemented track adjustment tools, i.e. a way to drag the
> track through points where the map tells you that it had to pass, and
> the in rubber band fashion adjust all the track points between
> junction/fix points?

You can force the map to pass through particular points. (Not by dragging, though, because that doesn't work well on a touchscreen.) There is no automatic adjustment of intermediate points, however. What you can do is manually eliminate a series of intermediate noise points by connecting two good points.

I have been doing my testing on some noisy tracks, and, although this is inherently a tedious task, I found I was able to clean up the garbage fairly efficiently. And, if there are multiple tracks, I've found good results from averaging the tracks, after trimming off the worst of the noise.

Lew Lasher

[Terje Mathisen]

lewl...@gmail.com wrote:
> Terje Mathisen wrote:
>
>> I wrote track reduction/optimization code a long time ago, i.e.
>> even before the end of Selective Availability when track points
>> could be up to 100 m off, but the error was random and slowly
>> changing.
>
> I wrote the reduction and averaging code some 10 years ago, but I did
> not use it a lot because it was not integrated with the track editing
> tools I was using.
>
>> Have you implemented track adjustment tools, i.e. a way to drag
>> the track through points where the map tells you that it had to
>> pass, and the in rubber band fashion adjust all the track points
>> between junction/fix points?
>
> You can force the map to pass through particular points. (Not by
> dragging, though, because that doesn't work well on a touchscreen.)
> There is no automatic adjustment of intermediate points, however.
> What you can do is manually eliminate a series of intermediate noise
> points by connecting two good points.

You should take a look at QuickRoute, a tool made by a Swedish Orienteer.

It allows you to fit arbitrarily many fix points between the map and the
track, and all other track points will be moved proportionally:

http://www.matstroeng.se/quickroute/en/

Terje

>
> I have been doing my testing on some noisy tracks, and, although this
> is inherently a tedious task, I found I was able to clean up the
> garbage fairly efficiently. And, if there are multiple tracks, I've
> found good results from averaging the tracks, after trimming off the
> worst of the noise.
>
> Lew Lasher
>

[lewl...@gmail.com]

> track editor that runs on Android tablets, and it is now available for beta test on the Google Play app store

And now it is generally available on Google Play: just search for "GPX Track Editor".

Lew Lasher
Cambridge, Massachusetts

[Craig Wallace]

Google Play says its not compatible with my phone (Moto G with Android
5.1), any reason for that?
Looks like a useful app, I would like to try it out.

Craig

[lewl...@gmail.com]

Craig Wallace wrote:

> Google Play says its not compatible with my phone (Moto G with Android
> 5.1), any reason for that?

It is probably enforcing a minimum screen size that I put in, just because I was annoyed that the app store labelled the app as "designed for phones", which I found misleading. The app was, in fact, designed for *tablets*. It can run on phones, but it is less convenient on a smaller screen.

> Looks like a useful app, I would like to try it out.

I don't want to discourage you from trying it out, so I'll put up an update with less stringent requirements.

Lew

[lewl...@gmail.com]

The revised version (build 41, still "Version 1.0") is now available for free download on Google Play, and, in fact, I was able to successfully download and install it onto my deluxe $30 smartphone (a ZTE "Maven" Z812, which has a whopping 480x854 screen resolution).

True confession: the app DOES run on smartphones, and I did in fact make special provisions for small screens: the buttons - which are all labelled with text, rather than icons - have tiny little abbreviated names. For example, the top row of buttons, which names the 4 main screens, is F, E, T, and S, instead of FILE, EDIT, TRACKS, and SEGMENTS.

If you find yourself puzzled by these abbreviations, you can get some clues from the context-sensitive help, by pressing the H (stands for "HELP") button in the top-right corner of the screen.

Personally, I do not find it convenient to use a GUI editor with a small screen and with a fat finger instead of a mouse or other more-precise pointing device. But I designed the app so that you could get your work done if you were stranded somewhere out in the field (or forest) with nothing but a $30 smartphone. (Actually, the more expensive phones give you more pixels, but that just means more pixels for your now-even-less-precise fat fingers to span.) In particular, you can use the SEGMENTS (S) screen to locate tiny little track segments (even 0-length segments), and then hop over to the EDIT (E) screen to delete (DEL) them or join (J) them.

Good luck,

Lew