Satellite navigation? How strong is the signal?

I was wondering if a satellite navigation will work anywhere.. including over/around steep mountains like yosemite natl park? Is the signal from a satellite navigation system same as a signal from a cellphone?|||The GPS satellites fly in a variety of orbits which mean that for most places on the Earth's surface including Yosemite), your GPS receiver can "see" four different satellites. The navigation function normally requires three different signals, but CAN work for most purposes with two. While only one "bird" might be roughly "overhead" at any given instant the others are are going to be off at some angle toward the horizon, which MIGHT be blocked, at least partially, by buildings, mountains, dense trees, so you shuld try to get to a relatively clear spot if at all possible, to improve the reliablity of the signals your receiver needs to process a location|||It's not even close to being the same signal as a cell phone. The Satellites circle the earth at an altitude of about 19,000 miles, so the signal(s) is nearly straight down to a GPS receiver.|||Your questions are base on information about the older navigation system setup. But it operates differently now than what you may think.





Satellite navigate also known as GPS (Global Positions System) is not the only technology for your ground unit now. In the USA we now use the NDGPS (National Differential "GPS") among other stuff sold on the ground devices . Lots of new cool stuff going on. In the begining days you just used the GPS satellites.





Check out the website:"http://en.wikipedia.org/wiki/Di鈥?br>




Sites where DGPS beacons are located:


http://www.beaconworld.org.uk/files/worl鈥?/a>





There is a USA National radio navigation plan. No public user fees. Other technologies:


Check this site: http://www.navcen.uscg.gov/pubs/frp2005/鈥?/a>|||Cells use antennas. GPS is a satellite.