Method and system for determining a position of a target vehicle utilizing two-way ranging

A communication system for monitoring the position and velocity of an aircraft, the system comprising:

• a control station positioned on earth, the control station having a known position;
• at least three satellites orbiting earth and positioned in multiple planes, each of the at least three satellites having a communication link system communicating through a respective first signal link with the control station, wherein a position of each of the at least three satellites is known such that a range between each of the at least three satellites and the control station is known;
• and
• an aircraft having a communications transceiver for sending and receiving signals to and from each of the at least three satellites through a second signal link corresponding to a respective first link, each of the corresponding first and second signal links defining a path for carrying a signal between the aircraft and the control station via a respective one of the at least three satellites, wherein each of the paths is a two-way communication between a respective one of the at least three satellites and each of the control station and the aircraft, wherein each signal includes a unique Auslander-Barbano code division multiple access (AB CDMA) signal portion assigned to the aircraft and a data message portion, the data message portion being modulated by a wavelet-based finite-impulse-response (WFIR) waveform with the AB CDMA signal portion;
• wherein the control station includes a dual alpha-beta/extended Kalman-filter tracking loop which processes the signals to determine a range between each of the at least three satellites and the aircraft as a function of time for the signals to travel the paths, the position of the aircraft as a function of the ranges and the known positions of the control station and the at least three satellites, and the velocity of the aircraft as a function of Doppler shift of each of the signals during travel of the paths.