Relative navigation for precision rendezvous and station keeping using datalink signals

A method of guiding the follower aircraft to the lead aircraft for refueling with a precision rendezvous and station keeping relative navigation system, comprising the steps of:

• transferring data link signals between the lead aircraft and the follower aircraft over a datalink;
• determining a range between the follower aircraft and the lead aircraft with the datalink on board the lead and follower aircraft using ranging messages;
• determining azimuth and elevation of the follower aircraft using an antenna array and processing system on board the lead aircraft;
• wherein the antenna array and processing system performs the steps of:
• receiving follower aircraft transmission with a monopulse antenna;
• and
• determining azimuth and elevation angles to the follower aircraft in a monopulse receiver.

A method for guiding a follower aircraft to a lead aircraft using a relative navigation system comprising a datalink on board the follower aircraft and the lead aircraft for transferring data and for determining a range between the follower aircraft and the lead aircraft, said relative navigation system further comprising a monopulse antenna system on board the lead aircraft for determining azimuth and elevation of the follower aircraft, said datalink further performing the steps of:

• transmitting a first ranging message from the lead aircraft to the follower aircraft;
• storing a lead aircraft time of transmit (TOT) time tag at the lead aircraft;
• receiving the first ranging message at the follower aircraft;
• storing a follower aircraft time of reception (TOR) time tag at the follower aircraft;
• transmitting a second ranging message from the follower aircraft to the lead aircraft;
• storing a follower aircraft TOT time tag at the follower aircraft;
• receiving the second ranging message at the lead aircraft;
• storing a lead aircraft TOR at the lead aircraft;
• sending a data message from the follower aircraft to the lead aircraft with follower aircraft TOT and TOR;
• and
• determining relative range and time offsets using follower aircraft TOT/TOR in the data message and stored lead aircraft TOT/TOR.