3. Satellite Orbit and Scan

Choosing the optimal orbit is a critical step for designing satellite programs to meet given mission goals. Fundamentals of orbital mechanics, with emphasis on those relevant to meteorological satellites, are reviewed for illustrating the physical background behind different types of satellite orbits mentioned. While the geostationary orbit (GEO) stands on a very simple physical principle, the physics underlying low-earth orbits (LEOs), for which a higher-order spherically-asymmetric component of the earth’s gravity field (the \(J_2\) perturbation) is crucial, is far more complicated than GEO. This chapter provides a compact but complete derivation of the \(J_2\) perturbation formula along with its implications for LEO configurations. The second half of the chapter is devoted to an overview of the instrument design such as the field of view and scanning geometry.