Global positioning system (GPS) receiver held in a hand. The display shows the location of 12 of the 24 satellites of the GPS network. The receiver is locked on to 5 of them,with signal strengths seen at lower centre. There is a weak signal from a 6th satellite. These satellites trace precision orbits around the Earth,and transmit radio signals that are detected by this receiver. Three signals allow calculation of the user's latitude and longitude. A fourth signal allows altitude calculations. Time information transmissions allow calculation of the local time | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Molloy, Cordelia |
Taille de l’image : | 3206 px × 4379 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |