GPS Data Logger

Data loggers
Typical GPS logger

A GPS logger simply logs the position of the device at regular intervals in its internal memory. Modern GPS loggers have either a memory card slot, or internal flash memory and a USB port. Some act as a USB flash drive. This allows downloading of the track log data for further analyzing in a computer. The tracklist or point of interest list may be in GPX, KML, NMEA or other format.[1]

Most digital cameras save the time a photo was taken. Provided the camera clock was reasonably accurate, or the GPS was used as a time source, this time can be correlated with GPS log data, to provide an accurate location. This can be added to the Exif metadata in the picture file, thus geotagging it.

In some Private Investigation cases, these data loggers are used to keep track of the vehicle or the fleet vehicle. The reason for using this device is so that a PI will not have to follow the target so closely and always has a backup source of data.