I am actually a software guy and only know a little about electrical engineering in general. (Since this crazy idea has come to mind, I am teaching myself as much as I can.) I do not yet know what I can realistically accomplish on my own.
I want to build a scaled down GPS system for an area about the size of my house. I would like it to be accurate to about 1 or 2 cm.
It would incorporate 4 GPS like transmitters and a number of receiver units. This would allow me to read the receiver unit's relative position in area surrounded by these transmitters. I only care about tracking within my house, and possibly right outside, but not any further. NOTE: I do not care about global position, only relative to my transmitter area.
Based off my limited knowledge of the real GPS, building my own doesn't seem to be outside my technological capabilities.
This is based off these facts: The real satellites use RF waves to send these psuedo-random data streams and the unit compares its local copy of psuedo-random stream with the "delayed" satellite streams. (Delayed due to large distance RF waves have to travel.) This delay is used to calculate distance and eventually exact position of the unit. Using four satalites, it can triangulate position and calibrate it's own clock to be reasonably accurate.
My transmitters would have to have very accurate clocks, but I could also calibrate these as often as needed.
So, is this even possible? Is it too far fetched to even consider trying? Yes, I expect it to be hard, but would a seasoned EE profesional be able to pull this off?
Real GPS solutions that have sub-meter (let alone 1-2 cm) accuracy are very expensive: $30k - $50k.
One other note, this system would be incorporated into a potentially lucrative product, if it worked. It would be worth all the trouble it would take to build.
Even further, does something like this exist allready? or would someone be interested in building this for me? This is a small step to my "real" idea, which has nothing to do with surveying, mapping, or any other global positioning problems.
Thanks in advance and I hope this is the most appropriate group to be posting in.