Geotagging example 2

As a quick proof of the Geotagging concept (explained in Spanish here) for use in vegetation research I spent quite literally no more than fifteen minutes of my time producing a KMZ file with images of the vegetation in the field next to my house, this afternoon. This was in response to a message from a colleague who was concerned that the technique could be overly  time consuming. In fact it is much more likely to be time saving.

If I had laid down standard sized quadrats and used higher resolution settings on the camera I  imagine that it would be quite  possible to produce standardised cover estimates for most of the species in the quadrats after the event (perhaps a a job for the  long winter evenings if the work were done in the UK) , although admittedly some of the smaller cryptic species could be missed.

The spatial error was no more than 3m in my case. The spatial relationship between the “quadrats” is also correct. There is a limit to the zoom on the photos when they are looked at within Google Earth itself. However  a high resolution image could always be zoomed into using other software. The nice feature of using GPicSync is that the geographical information is permanently written into the file header for posterity. When spatial visuliazation techniques become more sophisticated they will be able to use this information. However if it is not placed within the photo at the time it is taken it could be lost.

To look at my example download the file below and rename it to somethig with an *.kmz extension. For example quadratsexample.kmz. Then open it in Google Earth (downloaded from http://earth.google.com/download-earth.html)

quadratsexamplekmz

My own geopositioning was achieved using an ultra cheap NMEA gps attached to the  laptop I call tiny (for characteristics see https://duncanjg.wordpress.com/2008/09/10/ssh-dont-tell-anyone-its-so-easy/). The setup under Linux that I explained previously works very well  with tiny and is very convenient to use once it has been configured.

As I understand it Windows users can get a version of gpsbabel with a graphical user interface that can be used with a Garmin GPS from here

http://www.gpsbabel.org/download.html

And  they can download GpicSync from here.

http://code.google.com/p/gpicsync/

I did get a missing dll message when I tried it on my version of Windows XP. I solved it by following instructions here

http://code.google.com/p/gpicsync/wiki/TroubleShooting

But I do confess that I still haven’t gone through the whole process using Windows and Garmin. It should be extremely simple. All that is involved is

  1. Check that the camera time is set exactly.
  2. Check that the GPS is receiving enough satellites when in the field.
  3. Record waypoints or save a tracklog at the time when the photographs are taken.
  4. Download the recorded waypoints or tracklog to the computer in gpx format using gpsbabel.
  5. Import the photos to the computer.
  6. Run GPicSync to add the coordinates into the photo headers and build the kml file based on correlations between the gps coordinate time stamps and those recorded for the photos by the camera.

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