A GPS-based unit that is designed for handheld operation or windshield/dashboard mounting in a vehicle. Devices for vehicle use offer many of the navigation features of in-dash units and can run for several hours on battery before being plugged into the car's power outlet.
One disadvantage of portable GPS units is their inability to track satellites when there is no line of sight such as in deep valleys, on streets with tall buildings or lower levels of bridges (see in-dash navigation for more details). See GPS, GPS augmentation system and Google Navigation.
In the Car
This Magellan unit offers most of the navigation features of in-dash units, including text-to-speech playback of street names. Portable GPS screens range from 3" to 7".
With the advent of smartphones, people can get directions at all times, and the navigation apps are as good as dedicated portable GPS units but not as comprehensive as factory in-dash models.
Into the Wilderness
This Garmin GPS includes topographic maps for hikers and high-tech treasure hunters (see geocaching
). It also supports the WAAS augmentation system for improved accuracy. (Image courtesy of Garmin Ltd., www.garmin.com)
Built for Runners
This Garmin sports watch provides greater accuracy than a pedometer and helps runners find their way home in unfamiliar territory. It also attaches to a heart monitor via a wireless connection. (Image courtesy of Garmin Ltd., www.garmin.com)