MikesTooLz said:
GPS satellites are floating in space circling the earth constantly moving.
You will never have the same satellites above you at the same location, whatever ones are above you and within range are all you will get. If for any chance the ones you can see at that time are not positioned in such a way to be around you or having a good amount of distance between them you will not get a good triangulation.
For this reason your GPS accuracy can not only vary by the day, but it can actually vary by the minute as the satellites above move across the sky.
if you have an iphone there is a free app called P-Tracker Satellite Viewer. This will show what GPS satellites are currently above you, where they are located and where they are moving.
Where did you get that information from?
GPS satellites are stationary in relation to earth in orbiting us. How else could position be calculated?
"The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.[1] The system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver."