I was asked recently about my GPS tagging workflow. Something which I haven’t given much thought too, and I haven’t been that doing that consistently. This post basically describes the method I find most convenient now.
- Moves (iPhone app collects location data) – http://www.moves-app.com/
- Moves Export (Exports Moves data to GPX file) – http://www.moves-export.com/
- Adze (Mac app to merge/edit GPX data) – http://kobotsw.com/
- Aperture (apply the location data to photos) – https://www.apple.com/aperture/
Logging GPS data with Moves app
There are a number of ways to get the GPS data needed to tag the files. I have tried several. GPS photo loggers can collect a lot of data and usually have a pretty good battery life. But there are not many options, most are not mac compatible. I tried one of these, but got a faulty unit and gave up on it. Full GPS units, like Garmin, also collect data that can be downloaded. But the units are generally bulkier and the screens require more battery usage. iPhone apps are good, because I always have my phone with me. I have used a few different apps here too, Runkeeper is good if you want to also track your exercise progress, but I have used it just because it outputs GPX files. Placetagger is another app that is good for just recording a GX track, and now that it saves the files directly to dropbox. Saving the export step. Both apps worked well, but I found that I would forget to turn them on, and they had a pretty big hit to the battery life of the phone.
The Moves app is always on. So there is never the need to remember to turn it on. It has a fairly low battery draw. But it does have some, so I do carry a backup battery for my iPhone. It records locations, so I can easily review the days activities. it also records my steps, bike rides etc. And it does a really good job identifying them. But the moves app itself only provides a visual way of seeing your daily activities, and only exports images of the day. Once the developer opened up the app to other developers it became possible to get the raw GPX data out, and is now my primary method for recording my data for Geotagging.
Downloading the GPX Data
The Moves Export (http://www.moves-export.com/) service allows you to pull down the Moves data in a GPX format. You have to setup moves to share the data, and give Moves Export permission to access the data. But once you have completed that, it is really easy to pull down each days data file.
- Start at the “Your Storylines” tab,
- Navigate to the day
- Click on the “GPX” button.
If you are looking for a particular day, it may seem cumbersome to navigate day by day with the forward/backward arrows. But you can easily just change the date in the URL string, which ends with soemthign like startdate=20140228 (startdate=yearmonthday) to the date you want to download. If moves has data for that day you will be able to download it.
Merging data tracks with Adze
Aperture (Lightroom behaves similarly from my understanding) does not work well with multi-track GPX files. Which is most GPX files from moves. There are not a lot of GPX editing apps for Mac. And from the few I have seen, Adze has the best UI. Most of the time I simply use it to merge tracks, but I have also used it to deleted errant GPS points with the GPS point editor. You can also export a KML file if you want to view your location data in google earth.
To merge a multitrack GPX to a single track file
- Open the GPX file,
- Select all tracks
- Choose Merge Selected Tracks from the select menu
- Save (or Save as…)
Tagging image files in Aperture
Aperture and Lightroom store the location metadata in the applications database, and do not in the original RAW files. Aperture’s tagging is a little different than others I have seen. I believe Lightroom simply tags the selected files based on their times. Another app I have used, GPSphotolinker, also uses the times. Aperture requires you to drag the selected files over the point on the GPS track that matches the first image. This usually is not too hard and would theoretically allow you to shift the set if you time was off a few minutes. But if you have a lot of overlapping tracks, it can be harder to live up than you expect. Otherwise the steps are strait-forward.
- Load the GPX track
- Select files and drag them to the correct point on the track for the first track
I used to use GPSphotolinker. Which gave the option of recording the GPS data in a sidecar file, or in the original raw file. But since it no longer works with the current Mac OX. They do make a commercial program called Photo Linker Pro which is compatible, but is not free like GPSphotolinker. I am sure it is an excellent program, but I decided to stick with the Aperture only method instead of buying another app.