Hello DNRGPS,

I have also reported this DNRGPS bug in the EXIFTOOL forum. This seems to be a DNRGPS bug.

In the EXIFTOOL forum, see the Bug Reports/Feature Requests section with the thread "parsing a gpx file generated by dnrgps" for additional info.

I was doing some mapping and geotagging on July 7, 2012. I wear a Garmin Foretrex 301 on my left wrist and a Garmin Forerunner 305 on my right wrist--I like to have duplicates.

The Garmin Foretrex 301 behaves like a USB device. DNRGPS can also retrieve tracks from the 301 like other Garmin handhelds.

I tried to geosync my photos.

I used the EXIFTOOL utility to sync the gpx track with the photos.

So, I did two tests with the Garmin Foretrex 301.

1) geotag the photos with the Garmin file copy/pasted from the 301 as a USB device (the current.gpx file).

2) geotag the photos using the gpx file retrieved by DNRGPS.


EXIFTOOL would not geotag the photos in test 2--the file retrieved by DNRGPS.

There seems to be a problem with DNRGPS using local time for both Z time and localtime.

Since it is the exact, identical gps track, the lat/lon/time for the track points must be identical
for both the Garmin file and the file retrieved by DNRGPS.

If I am in the Zulu time zone, both Z time and local time would be the same.

Since I am in EDT, local time should be (Z time - 4). Local time and Z time are not the same.

When one looks at the table created by DNRGPS, Z time is correct. The problem is
that local time is written for the track point instead of Z time. The time of the track point
should be Z time and not local time. Local time should be in the extensions section of the gpx file.

I have attached the two gpx files 1) current.gpx copied from the 301 and 2) the gpx file retrieved by DNRGPS.

It seems to me that the track points must have the same Z time.

Incidentally, I retrieved the gpx file from the Garmin Forerunner 305. It seems the track point Z times are not correct, either.

It appears that DNRGPS is writing local time for the track points instead of Z time.

Cheers,
Frank Davis