TDOA-based positioning system using terrestrial wireless signal sources

A system, comprising:

• a correlator configured to correlate a first set of samples taken by a first receiver of a terrestrial wireless communication from a terrestrial wireless source with a second set of samples of a replica of the terrestrial wireless transmission to determine a correlation peak, wherein the first set of samples are time-stamped with a time of receipt according to a first clock in the first receiver, and wherein the second set of samples are time-stamped with a time of receipt according to a GPS clock in a second receiver that is remote from the first receiver;
• and
• a time-difference-of-arrival (TDOA) generator configured to determine a first pseudorange between the first receiver and the terrestrial wireless source based upon the correlation peak and a time of transmission for the terrestrial wireless communication, wherein the terrestrial wireless source is selected from the group consisting of a cellular base station, a WiFi source, a Bluetooth source, and a wireless drone.