What is GPS?

I recently read of a hunter overdue home from a squirrel hunting trip. He had slipped and fallen and was suspended upside down by his leg, which was caught in rough terrain. Fortunately, he had a Global Positioning System (GPS) and satellite messaging device that allowed him to contact emergency dispatch. Search and Rescue were able to pinpoint his location and rescue him from his life-threatening situation. In a world where technology continually reshapes our lives, GPS stands out for its profound impact on navigation and exploration.......

This is one of several blogs written for Field and Stream, read the remainder at this link