I've worked as a surveyor myself for a year or so, using GPS.
We used GPS to provide fixed base points to conduct land surveys in various different locations, cities, countryside, and anywhere in between. We have to be very careful about GPS receiver placement in built up areas due to reflections from high buildings etc, and also in countrysides under heavily wooded areas. However, with a clear sky, the GPS units would work perfectly.
The GPS units we used actually gave us readings of numbers of satellites in the sky and their positions with bearings etc, which moved throughout the day.
This implies to me that there actually satellites in the sky. Please explain how this works without the use of satellites in giving an accurate system of measurement? Or am I in the conspiracy aswell?