Design of satellite formations for interferometric and bistatic SAR

This paper deals with orbit design for formation missions aimed at interferometric and bistatic SAR observation. In particular, an analytical second order model is derived and discussed, which describes relative motion between two satellites both moving on low eccentricity orbits. This model generalizes previous derivations and has satisfying accuracy on distances of the order of hundreds of kilometers. Developed equations are used to design a propellant-effective maneuvering strategy to acquire observations with increasing bistatic angle, while keeping an acceptably low collision risk and maintaining the passive radar near the elevation plane of the transmitting one. The basic concept is optimize parameters’ choice so as to exploit Earth oblateness differential effects. In particular, a combination of differences in inclination (order 0.1°), eccentricity (order 10-4) and semi-major axis (order 10 m) is used.