Why do we use satellites rather than broadcast towers for navigation?

It would seem more economical to build and maintain towers than launch things into orbit.|||GPS system is already in place, for aircraft, spacecraft, and ship navigation. So why not use it for autos, instead of developing a (more expensive) new system with millions of towers?





.|||both are used in different ways


terrestrial radar is the primary method for navigation both airborne and nautical vessels


GPS augments this by allowing active local [i.e., shipboard] position information and control


advantages of orbital navigation include a primary concern for security - it is much harder to shoot down a sattelite than it is to take out a radar or broadcast tower|||Draw a circle (the earth). Now draw a tiny mast on one side and a tiny you on the other side. Can you see it? No. Can you communicate?...No





Now put a satellite in space mid way between you and the mast. Can you see it?...yes...can the transmitter see it...yes...OK Now you can communicate.





So you can have 1 satellite that everyone can see or millions of transmitters because of the earth's curvature.





Now which is more economic?|||okay you have it kinda wrong..... the signal goes from the GPS to the tower then up to the satellites then back down threw the tower then back to your GPS. so we use both..... and its actually more efficient to go straight from satellite to GPS, stronger signal and faster, and less cost, and less cancer for the rest of us living