Autonomous Initial Orbit Determination with Optical Observations of Unknown Planetary Landmarks

Images are commonly used for spacecraft navigation. When close to the observed body it is often advantageous to perform such image-based navigation with observations of landmarks. This work demonstrates that it is possible to solve the initial orbit determination (IOD) problem using only observations of unknown landmarks if the spacecraft is assumed to be orbiting an ellipsoidal central body of known shape. Further, the solution developed here is noniterative and is based purely on geometric arguments. Example autonomous IOD results using only unknown landmarks are shown for a spacecraft in a circular Mars orbit and an elliptical Earth orbit.