Geotagging photos of key outcrops or geoscapes in the field is a very useful thing to do. To geotag a photo is to inscribe the digital file with geographic coordinates. Lots of people are doing it, but I fear that not enough geologists are.
All photo files from digital cameras have an exif header. This stands for ‘exchangeable image file format’ and it is the area where the file name, date, time, exposure, etc., info is stored. Recent interest in digital mapping has lead to the ability to add specific geographic information (i.e. geographic coordinates) to the exif header. This offers great potential to the field geologist. There are various ways to geo-tag a photograph. Up to now, my preferred way has been to use the free photo-sorting program Picasa (yup, a Google product…more on this at related post) wherein you can manually link a photo to a specific location by dragging it to the map. This works fine in many situations, but can be tedious. Over the last couple of days, I have experimented with a more automatic approach using a program called ‘Geosetter‘ which very efficiently and easily geotags my field photos by directly linking their time-stamp with a corresponding GPS tracklog. Brilliant! In this way, you automatically create a geographically accurate set of field photographs. If you use Google Maps, Picasa, or Google Earth, you can then display the images on a base map of your choice.
Check out an example I made using a Picasa Web Album:
Once at the album, click the ‘view map’ link. Be sure to zoom way in using the satellite mode to fully appreciate how useful this application is. Furthermore, consider the fact that some of your field photos may be of great value to other geologists, botanists, historians, etc., at some point in time. By tagging them with key words, geo-tagging them, and making them available online, you may be doing a great service to other scientists. Burying them in a paper archive or on a CD somewhere does no good.
Note, you can use Picasa to geotag your photos one-by-one through a link with Google Earth, using a simple drag-and-drop procedure. At some point it is obvious that digital cameras will automatically stamp the file with the coords, but I think the linkage between digital photos and a GPS tracklog may be the best way to go.
Are you the creator of an intricate directory structure in which you try to keep track of your digital photos? Have you actually saved multiple copies of a photo in order for it to be represented in relevant folders? I was once such a fool. For several years now, though, I have been using Picasa, a free and simple photo organizing program that allows you to tag your photos with key words instead of storing them in directories with key names. This turns out to be an extremely useful application if you have lots of digital photos. Tagging items with key words is superior to elaborate directory structures. Consider the following situation: You have a photo of a key outcrop in a specific map area that conveys multiple types of information. You can store that photo in a directory that is keyed to that map area and hope to remember that it also contains information relevant to other areas or geologic concepts.
Example from my work: Spirit Mtn. Northwest quad; Colorado River Sediment; Bullhead alluvium; erosional unconformity; sediment sample location.
What to do with this much information? By using tags in Picasa, I can store one copy of this image in a directory of my choice, but then tag it with all of those labels (likely shorthand versions like SMNW; Tcb; Unf; SSamp) so that all I have to do is search on the tag to find the image. Easy? Yes.
Picasa isn’t the only program that does this, but I use it exclusively because I can so easily then link the photos with Google Maps, Google Earth, and any of my blogs (also, it is free). Be sure to check out the related post about geotagging photos and displaying them in a Picasa Web Album. The preceding screen-snag of the interface shows the basic layout. The circled area shows a compass rose icon indicating that the image has been geotagged and an arrow that indicates that it has been uploaded to a Picasa Web Album where the photos can be viewed in relation to the point from which they were taken in the field.
It should take you only 30 minutes to figure out how to use the program. Note that it will automatically search your computer for images and if offers some basic image editing functionality.
Another option for providing spatial context for geologically oriented photographs is to geotag them in an online photo album that links to a map. Here is an example made using Picasa, a very handy (free) photo organizing program that can geotag photos for viewing in Google Maps or Google Earth: Geotagged Photo Example