Method to modify calibration data used to locate a mobile unit

A method for determining a location of a mobile station, comprising:

• providing a database of previously-gathered calibration data for a predetermined region in a wireless network, wherein said network includes a serving transmitter;
• collecting observed network measurement data including a first signal characteristic from said serving transmitter, the observed network measurement data collected by the mobile station and transmitted to the network or collected by the network;
• modifying said observed network measurement data using said first signal characteristic;
• and
• comparing said modified network measurement data with said database of calibration data to thereby determine the location of the mobile station.

A method for determining a location of a mobile station, comprising:

• providing a database of previously-gathered calibration data for a predetermined region in a wireless network;
• collecting observed network measurement data from each of a plurality of transmitters including a signal characteristic from each one of said plural transmitters, the observed network measurement data collected by the mobile station and transmitted to the network or collected by the network;
• determining an average value for select ones of said signal characteristics;
• modifying said observed network measurement data using said average value;
• and
• comparing said modified network measurement data with said database of calibration data to thereby determine the location of the mobile station.