Learn how GPS photo taggers function and improve your photography experience.

Initially designed for military use, GPS technology now powers many of the coolest consumer devices. It's what drives navigation systems in vehicles, helps your phone pinpoint your location, and allows you to tag photos with accurate geographic details.

GPS photo tagging, or geotagging, involves adding geographical data like latitude, longitude, and altitude to your digital photos. This feature is part of a broader trend of categorizing and organizing content through tagging.

Rather than relying on search engines like Google to tell us that a blog post is about Bill Gates' effort to eliminate malaria, the blog creator can tag the post with terms like "Bill Gates" and "malaria." The same principle applies to photos. On platforms like Flickr, users can tag their photos with details such as the people or places shown and the location where they were taken (e.g., "San Francisco" or "Ames, Iowa"). Other users can search or explore by tags to find the most relevant content.

GPS photo tagging simplifies the process of tagging images online. When you upload a geotagged photo to Flickr, the site automatically places your photo on its interactive world map. Other users can then search for and view photos from your exact location.

GPS photo tagging helps organize your personal photo collection. In the past, to find a specific photo on your computer, you needed to remember the date it was taken. But with geotagged photos, you can simply search for "Philadelphia" and see all the photos you took there.

GPS photo tagging has professional uses as well. Film location scouts can map out all the photos they took during a location search in Ireland. Real estate agents can offer clients an interactive photo map of properties. Archaeologists can link photos to other geographic data when planning excavations.

Keep reading to discover more about how GPS photo tagging works and explore some of the most exciting geotagging applications.

Understanding the Functionality of GPS Photo Taggers

When you capture a photo with a digital camera, it doesn't just save the image; it also records additional information like the exact time and date the photo was taken, camera orientation (portrait or landscape), flash usage, and detailed settings such as aperture, exposure, and focal length. This data is stored in the photo's EXIF header.

EXIF, which stands for Exchangeable Image File Format, is a system for embedding data into photos that can be read by other software and websites. This is how your computer can automatically organize your photos into folders (like one titled February 28, 2009) and rotate them based on the image's orientation.

What makes EXIF headers exciting is that they offer space to store geographical details like longitude, latitude, and altitude. In recent times, we have seen the rise of new hardware and software tools that integrate GPS technology to embed location data into EXIF headers.

To better understand how this works, let's guide you through the steps of manually adding GPS tags to a photo using a basic digital camera and an affordable GPS receiver.

Manually tagging each photo with GPS coordinates can be a bit tedious. While there are several free and shareware EXIF editors available online, there's no guarantee they'll work flawlessly on every operating system. As of now, Apple's iPhoto '09 is the only widely used photo editing software that allows you to manually input GPS coordinates into an EXIF header [source: Shankland].

Fortunately, many new tools—whether hardware, software, or online apps—make it simple to tag your photos with GPS data and share them via interactive online maps. Continue reading to discover more about these innovations.

Applications of GPS Photo Tagging

One of the simplest methods to automatically tag your photos with GPS information is to purchase a camera equipped with a built-in GPS receiver. At the high end of the market, you have devices like the Ricoh 500SE, which is specifically tailored for GIS professionals. This camera not only comes with a built-in GPS chip but also offers Bluetooth connectivity for pairing with an external GPS receiver, ensuring even more precise location tracking. Every time you snap a photo, the camera stores the GPS data directly into the photo's EXIF header.

For hobbyist photographers, the availability of compact point-and-shoot cameras with built-in GPS chips is rapidly increasing. Additionally, mobile phones like the Nokia N78 now come equipped with both a camera and a GPS chip, making it easier than ever to capture geotagged photos on the go.

Another choice is to purchase a compact GPS receiver that can be attached to your camera. Nikon offers a small GPS tagging device that connects to the flash "shoe" on its premium digital SLR cameras.

For a GPS photo tagging solution that is compatible with all digital cameras, consider using a portable GPS tracker. Simply activate the device, tuck it into your pocket, and take photos throughout the day. When you're ready to upload your photos, remove the camera's memory card and insert it into the GPS tracker. The tracker will automatically embed the GPS data into the EXIF header of each photo. Then you can upload your images as usual.

One intriguing option is the Eye-Fi Explorer, an SD memory card that contains a small WiFi transceiver. While it doesn't connect to satellites like a traditional GPS unit, it communicates with WiFi base stations to obtain geographical data. This might be ideal for city photography but less effective in rural or remote locations. It's also not as precise as a GPS receiver [source: Gross].

A growing number of websites allow you to view your geotagged photos on a map and share them with others. Flickr is one of the most popular platforms for mapping photos. Even if your photos aren't automatically tagged with GPS data, you can manually place them on a map by dragging and dropping them, and adding longitude and latitude coordinates. However, this requires manual input, as Flickr doesn't automatically extract information from the photo's EXIF header.

To upload previously geotagged photos to Flickr, head to your account settings and toggle the "Import EXIF location data" option to "yes." By default, Flickr keeps this setting on "no" to protect user privacy. Once enabled, Flickr will automatically map your GPS-tagged photos. You can even create custom, smaller maps to share with your friends.

Two other photo-sharing platforms, Picasa and Panoramio, both owned by Google, allow you to upload images, create interactive photo maps, and even view and share your pictures through Google Earth. Google Earth is a free application that lets you explore 3D satellite images on a virtual globe, offering the ability to zoom in and search for locations.

Both Picasa and Panoramio give you the option to create a .kml file from your uploaded photos or entire albums. If you think of Google Earth as a type of web browser, then .kml files are similar to HTML files [source: Google Earth User Guide]. Google Earth processes these .kml files and displays your photos exactly where they were taken on the virtual globe. What's more, you can share your .kml files with others to showcase your geotagged photos.