Oregon Hikers

I use the Gaia app on my iPhone to record GPS tracks of hikes. I've never had to clean up tracks before, but on some recent hikes there has been A LOT of drift that has added miles onto my hikes. I've never had this happen with Gaia before so I'm looking to clean those tracks up. What do you all use for this? I tried this in Caltopo, but it seems like an incredibly painstaking process, deleting all the extraneous points one by one by one (unless I'm doing it wrong.) I know about GPS Track Editor, but it's Windows-only and I have a Mac.

related to that

I have zillions of tracks, including many tracks for some hikes

I wish there was a way to average all the tracks for the same hike, then have gaia just display that rather than all the (noisy) duplicates

You could try JOSM:
https://josm.openstreetmap.de/

Its real purpose is editing OpenStreetMap data, but it can be used to manipulate any coordinates. (Just don't upload them to OSM.) You can batch-select multiple nodes and drag them around, or you can use the line-editing tool (invoked with the "W" key) to interactively reshape a track.

If you want to try it, the process is: open a GPX file; "convert to data layer"; and then re-export it as GPX again.

Can you post some screenshots so we can see what you are trying to do?

Some smartphones use the cell network as well as GPS to determine your position. Putting the phone into Airplane Mode while recording forces the phone to use only GPS so that intermittent cell phone reception doesn't throw your position off.

RobinBaker wrote: ↑

December 18th, 2021, 11:56 am

Can you post some screenshots so we can see what you are trying to do?

We stopped for a break at this trail junction. When I checked our mileage upon arriving and again upon leaving there was a difference of 0.3 miles from all the bouncing around the GPS did while we were standing there. I've never had this happen so severely before with Gaia.

Even when we were on the move the GPS was doing a lot of zigging and zagging.

RobinBaker wrote: ↑

December 18th, 2021, 11:56 am

Some smartphones use the cell network as well as GPS to determine your position. Putting the phone into Airplane Mode while recording forces the phone to use only GPS so that intermittent cell phone reception doesn't throw your position off.

I'm pretty sure I was in airplane mode, but I'll keep this in mind for future.

justpeachy wrote: ↑

December 18th, 2021, 3:27 pm

We stopped for a break at this trail junction. When I checked our mileage upon arriving and again upon leaving there was a difference of 0.3 miles from all the bouncing around the GPS did while we were standing there. I've never had this happen so severely before with Gaia.

That looks like pretty normal signal wiggle to me, especially if you were under dense trees.

At any rate, if that's the sort of mess you're looking to clean up, run your file through GPS Visualizer's GPX converter and enable the trackpoint distance threshold: https://www.gpsvisualizer.com/tutorials ... lters.html

Interestingly Garmin Basecamp is really easy and useful for many things including this. You can adjust elevation anomalies, geometry, attach photos to the track. I'm a GIS professional and I find Basecamp to sometimes be easier than all the other tools I have access too. JOSM and QGIS work too but the learning curve probably isn't worth it.

Adam has a good website for 'smoothing' tracks too

Judging from your second map, it looks like you are recording a lot of trackpoints. Does Gaia let you adjust this? That is, adjust how far you travel before another trackpoint is recorded?

I use Locus Map Pro, which lets you set both distance and time parameters for recording trackpoints. I have my trackpoint recording set to 33 feet (the default for their Hiking Profile) and 15 seconds. I also have the "Trackpoint recording condition" set to "Distance AND Time (both)" so that both parameters must be met for a trackpoint to be recorded. There's also another configurable parameter, "Record only when moving" which I have toggled to "On". That way, when I stop to take a break, the app isn't recording trackpoints. I can also just Pause the track recording and Resume when I begin hiking again. I don't use Gaia (some of my friends do and like it a lot), but it may have similar configurable settings.

You mentioned that you tried to do adjustments in CalTopo. Try importing your track again and using the "Resample" function. Once imported, click on the track and choose "Modify" from the choices offered, then choose "Resample", which lets you adjust the number of trackpoints. There are two parameters here: "Resample based on X" (I choose "distance") and "Create a point every X Y" where X is the desired distance between trackpoints (I use 50 a lot since I've configured it to record every 33 feet) and Y is "feet" from the drop-down (be careful here because the default seems to be "miles").


Hope this helps!

Robin

All of you posters to this thread are way awesome!

Happy Holidays and New Year to all!

Burnside

RobinBaker wrote: ↑

December 19th, 2021, 9:56 am

Judging from your second map, it looks like you are recording a lot of trackpoints. Does Gaia let you adjust this? That is, adjust how far you travel before another trackpoint is recorded?

Unfortunately Gaia does not have a setting like this, or the "record only while moving" feature. If I remember I can always pause recording when stopped, and resume when starting again.

Thank you for suggesting "resample" in Caltopo. I've never tried that before!