What Is Location Data?

Location data consists of bits of information encoded into the photographs you take that helps your camera or photo software accurately pinpoint the location of the photo you have taken. When you take a picture, there are two ways your photos can be automatically tagged with location data. The first is by GPS, and the second is by using a known Wi-Fi location.

Depending on the camera being used, you may have one of these technologies built into the hardware. For example, most smartphones, like the iPhone, have built-in GPS chips that will tag your photos with their location. Some newer cameras, like the Nikon Coolpix P6000 or the Panasonic DMC-ZS7 series, also have GPS chips built in.

The Global Positioning System (GPS) is a way for the device you are using, such as a phone or computer, to know where it is at any given moment. It does this via a built-in chip that receives coded transmissions from a number of satellites high above the earth. The built-in chip knows where each satellite should be at any particular point in time and can use that data to interpret and calculate its own location with great accuracy. In a camera with GPS capabilities, these coordinates are encoded in the EXIF information (see Chapter 3) of each photograph you take. That EXIF information is then extracted by iPhoto, which uses it to display your photos' locations on a map.