The Global Positioning System (GPS), formerly NAVSTAR GPS, is a satellite-based navigation system owned by the USA government and operated by the USA Space Force. It is one of the Global Navigation Satellite Systems (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. Obstacles such as mountains and buildings block the relatively weak GPS signals. The GPS does not require the user to transmit any data, and it operates independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the GPS information. The GPS provides critical positioning capabilities to military, civil, and commercial users around the world. USA government maintains the GPS system. It's freely accessible to anyone with a GPS Receiver e.g. A Garmin Device.

Garmin handheld GPS are the common mobile mapping GPS used for navigation, general GIS Mapping as well as Data Collection. The Garmin eTrex family retains the core functionality, rugged construction, affordability and long battery life that made eTrex the most dependable GPS device available. We improved the user interface and added a worldwide basemap, paperless geocaching and added support for spine mounting accessories. You’ll recognise the name, you’ll recognise the quality but the eTrex family of devices is an entirely new GPS innovation.