Autonomous spacecraft orbit navigation

The objective of this dissertation is to establish a novel method of autonomous orbit navigation of spacecraft completely independent of a ground tracking system. The dissertation is composed of four parts as a whole. First, the previous work, the concept and development of autonomous orbit navigation, and the motivation of this dissertation are introduced, and the configurations of orbits to be considered are explained: (1) an interplanetary spacecraft, (2) two spacecraft orbiting the Earth, and (3) a Sun synchronous spacecraft orbiting the Earth. The main kinds of measurements used such as a radial velocity (doppler measurement) due to the relative motion from a spacecraft to the Sun, a, line of sight vector to the Sun, a relative line-of-sight vector between two spacecraft, and a line-of-sight vector to the Earth are explained. The second part is addressed to the observability of the several measurement systems using an analytical initialization method (modified Laplace's method), and computational methods for each orbital configuration system in dimensional, nondimensional, rectangular coordinate system and orbital element coordinate system. The third part presents an analysis of the error covariance in order to evaluate the effect of different measurement choices, measurement frequency, and measurement accuracy through the covariance propagation based on an extended Kalman filter. The fourth part verifies the observability through example applications (and Monte Carlo simulations) using an extended Kalman filter for each main orbital configuration. These studies provide needed insights and constitute the first step toward establishing the feasibility of a novel method of autonomous orbit navigation of spacecraft.