Global positioning system (GPS) receiver being held in a hand. The system utilizes a network of satellites that orbit the Earth. Each of these sends out signals about its position and the time. The receiver uses the signals from at least four satellites simultaneously to calculate its latitude,longitude & altitude,as well as the local time | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Percival, Steve |
Taille de l’image : | 3424 px × 5131 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |