Systems and methods for IP and VoIP device location determination

A method of selecting a process of determining the position of a device connected to a computer network relative to a fixed coordinate system, said method comprising the steps of:

• estimating a position of a device relative to a fixed coordinate system to a first level of accuracy based on communication over a computer network with a network operations center, wherein said network operations center contains a database of locations of other devices on said computer network, and wherein said position of said device to said first level of accuracy is derived through said communication between said device and said network operations center over said computer network;
• obtaining data over said computer network regarding characteristics of a positioning system relative to said position estimated to said first level of accuracy;
• attempting to receive a plurality of signals from said positioning system;
• determining the quality of said plurality of signals from said positioning system;
• selecting between a first process where a time reference of said positioning system is obtained over said computer network and a second process where said time reference of said positioning system is obtained from said positioning system, wherein said selecting is based on a relative comparison between said quality of said signals from said positioning system in relation to said position of said at said first level of accuracy such that said first process is selected if said quality of said plurality of signals from said positioning signals is greater than said first level of accuracy and said second process is selected if said quality of said signals from said positioning signal is less than said first level of accuracy;
• determining local atmospheric pressure;
• and
• calibrating a barometric altimeter located in said device based on said local atmospheric pressure;
• wherein said estimating is at least partially based on said barometric altimeter.