Patent ID: 7136016

Claim:
A mobile platform tracking and collision avoidance system, comprising: a ground controller assigned to a geographic space; and at least one mobile platform communicating with the ground controller on a bi-directional communications link, wherein each mobile platform transmits a mobile platform signal comprising at least a time of transmission of the mobile platform signal; the ground controller transmits a ground signal comprising at least a time of transmission of the ground signal and a location of the ground controller; each mobile platform performs time-of-arrival (TOA) measurements on the mobile platform signals received by that mobile platform and also performs TOA measurements on the ground signal received by that mobile platform; the ground controller performs TOA measurements on each of the mobile platform signals received by the ground controller; each mobile platform determines an air range between a first mobile platform and another mobile platform and a ground range between the first mobile platform and the ground controller; each mobile platform determines a geodetic position based on at least the air ranges and ground range for the first mobile platform and the position of the ground controller; and the ground controller monitors each of the mobile platforms within the geographic space to warn each of the mobile platforms about possible collisions between mobile platforms.