GPS altitude
Hi,
I am in the middle of studying GPS navigation and I can't figure out how the reciever calculates it's altitude.
After recieving the NM and the CA code the reciever calculates its position by looking at the time delay between the sending and recieving of signal.
However, surely the altitude of the reciever will affect the range to the satalite and therefore its position, whether the unit is up a 40m mast on a ship, a 2000m mountain or an aircraft at 35000ft.
Am I right in thinking that the pseudorange is a 3d sphere?
Anyone help me out?
cheers
.. undeleted as it is useful for this to be revisited from time to time ...