Patent ID: 7370566

Claim:
A method for sensing and monitoring ICBM threats using a constellation of earth orbiting satellites, comprising: arranging a first plurality of threat sensing satellites in earth orbit with a first, common prograde orbit plane with a first inclination defining a first angle between about 30° to 70° with respect to the earth's equator and an Argument of Perigee equal to about 270°; arranging a second plurality of threat sensing satellites in earth orbit with a first, common retrograde orbit plane and a second inclination defining a second angle between about 110° to 150° with respect to the earth's equator and an Argument of Perigee equal to about 270°; selecting said second angle formed by said second retrograde orbit plane to be a symmetric conjugate of said first angle formed by said first prograde orbit plane; distributing said first and second plurality of threat sensing satellites respectively within said first prograde orbit and said first retrograde orbit with a Walker distribution of T/P/1; synchronizing a plurality of epochs of said first plurality of threat sensing satellites with a plurality of epochs of said second plurality of threat sensing satellites to provide uniform inter-plane satellite spacing; and monitoring an ICBM threat with at least one of said first and second plurality of threat sensing satellites.