Geotagging, also known as geocoding, is the process of adding location data to photos. This is done by adding latitude and longitude coordinate information into your jpg files.
In addition to actual photo data, jpg files include Exchangable Image Format (EXIF) metadata that contains information about the picture. Typically EXIF data includes details about the camera used to take the picture, camera settings, time, and date. The addition of coordinate information into the EXIF data means that users can determine exactly where a photo was taken.
While photographers must be conscious of possible privacy issues associated with geotagging photos, the ability to keep a mappable record of where your photos were taken can be very useful for travel photos. Never again will you forget where you were when you took that shot! Also, having a GPS record of the photo location means that you can physically return to that exact spot in the future, or in some cases virtually re-visit the location using Google Maps or Google Street View. The following map shows the location of a number of photos we geotagged. You can click on the dots to see the photos from our Flickr photostream.
View Average Traveller Geotagged Photos in a larger map
In order to geotag, you must have a GPS receiver and a camera. Some smartphones which have GPS and cameras built in are geotag ready. Some digital cameras are beginning to include GPS receivers for native geotagging capability, while some digital SLR cameras can interface directly with external GPS receivers.
Geotagging ready equipment is still fairly uncommon, so most people geotag by carrying a GPS receiver that keeps a trace of location data over time. The geotagger must then cross-reference this GPS trace with the timestamp on each photo. In order to do this efficiently you must synchronize the clock on your camera with your GPS and use some software to perform the cross-referencing.
The following posts cover the equipment that we used to geotag a small number of photos, provide a step-by-step guide for geotagging with free software, and describes what you can do with your geotagged photos.