+Happy Humphrey Posted May 4, 2014 Share Posted May 4, 2014 (edited) I wanted to georeference some photos, using the tracklog from a recent walk. My camera doesn't have GPS so I used the Etrex 20 to record the walk and made sure that the time was synchronised with the camera's time. It sort of worked, but I discovered that the time in the GPS tracklog is incorrect (even though the GPSr - software version 3.7 - showed the correct time). You can verify this by the following extract, which is the first few lines of the GPX file recorded in the unit. Note that the track is entitled "01 MAY 2014 12:24" but the first recorded point is 11:24:23. You'd expect that it has to be 12:24, otherwise why would it call the track by this name? Do I have to set something to correct this, or is it just a known bug? <name>Current Track: 01 MAY 2014 12:24</name><extensions><gpxx:TrackExtension><gpxx:DisplayColor>Cyan</gpxx:DisplayColor> </gpxx:TrackExtension><gpxtrkx:TrackStatsExtension><gpxtrkx:Distance>164187</gpxtrkx:Distance> </gpxtrkx:TrackStatsExtension></extensions> <trkseg> <trkpt lat="50.9105686750" lon="0.5760431942"><ele>16.48</ele><time>2014-05-01T11:24:23Z</time></trkpt> <trkpt lat="50.9106282704" lon="0.5761203077"><ele>17.44</ele><time>2014-05-01T11:24:30Z</time></trkpt> I had to edit the GPX file using Notepad and change all the times before the georeferencing could be made to work...a bit of a nuisance! Edited May 4, 2014 by Happy Humphrey Quote Link to comment
+Timpat Posted May 4, 2014 Share Posted May 4, 2014 I've found when goofy things like this happen I use WebUpdater to reinstall the firmware. When it says you have the most current version tell it install anyway. Quote Link to comment
MtnHermit Posted May 4, 2014 Share Posted May 4, 2014 I had to edit the GPX file using Notepad and change all the times before the georeferencing could be made to work...a bit of a nuisance! If you use BaseCamp for your GeoTagging, then it will do a global time offset +/- 24 hours in 1 sec increments, assuming all the times have the same "error". As a bonus you can see the photos in map context and use it's photo viewer to scan the photos, all the while the map moves to the viewed photo. It is the main reason I have BC on my PC. Quote Link to comment
+Timpat Posted May 4, 2014 Share Posted May 4, 2014 Hmmm ... just had a thought. Any chance this has to do with daylight savings settings? Quote Link to comment
+Happy Humphrey Posted May 4, 2014 Author Share Posted May 4, 2014 I had to edit the GPX file using Notepad and change all the times before the georeferencing could be made to work...a bit of a nuisance! If you use BaseCamp for your GeoTagging, then it will do a global time offset +/- 24 hours in 1 sec increments, assuming all the times have the same "error". As a bonus you can see the photos in map context and use it's photo viewer to scan the photos, all the while the map moves to the viewed photo. It is the main reason I have BC on my PC. Thanks for the tip. I didn't even realise that BC could geotag photos! I must say I never got into using Basecamp as I was put off my some of its quirks. Quote Link to comment
+EScout Posted May 5, 2014 Share Posted May 5, 2014 (edited) When you save a track, the name of the track on the GPSr has the time at the end of the track in local time. Track points are recorded in UTC/Z. Edited. Edited May 5, 2014 by EScout Quote Link to comment
+Red90 Posted May 5, 2014 Share Posted May 5, 2014 The times in the file are "Zulu" time. Your local time is must be 1 hours off of zulu. The computer will figure it out. Quote Link to comment
+EScout Posted May 5, 2014 Share Posted May 5, 2014 Now looking at your track points carefully, I see that it is reported in Zulu, and that you are not far off from 0 Longitude (positive, so east of 0 Degress, and one hour later.) Red90 is correct, your local time is 1 hour off. So, all looks good with your file name and track points. When you use a geotagging program, just make the appropriate time adjustment if your camera is set to local time. Quote Link to comment
+JohnCNA Posted May 5, 2014 Share Posted May 5, 2014 I have been geotagging photos with my track files from the eTrex 30, using the free software Geosetter. Just save your track file into the same directory as your photos. Geosetter reads the time stamp on the photos and matches it up with the time stamp on the track points. It automatically adjusts for the GMT on the trackpoints and daylight savings when you tell it what time zone you're camera was set to. It's very important that you set the camera's clock to match the time that your GPS shows you. Anyway, it's quick and almost automatic. And it allows manual override if you realize you made a mistake with your camera's time settings. Which of course, I've done several times now. Quote Link to comment
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