This work presents a new method for space-based angles-only orbit estimation.The approach relies on the integration of a novel and highly accurate Analytic Continuation technique with a new measurement model for multi...This work presents a new method for space-based angles-only orbit estimation.The approach relies on the integration of a novel and highly accurate Analytic Continuation technique with a new measurement model for multiple observers for inertial orbit estimation.Analytic Continuation computes the perturbed orbit dynamics,as well as the perturbed state transition matrix(STM),in the inertial frame.A new measurement model is developed for simultaneous measurements using a constellation of low-cost observers with monocular cameras for angles-only measurements.Analytic Continuation and the new measurement model are integrated in an Extended Kalman Filter(EKF)framework,where the Analytic Continuation method is used to propagate the perturbed dynamics and compute the perturbed STM and error covariance,with the measurements obtained via the new measurement model.Two case studies comprising small and large constellations of observers are presented,along with cases of sparse measurements and a study of the computational efficiency of the proposed approach.The results show that the new approach is capable of producing highly accurate and computationally efficient perturbed orbit estimation results compared with classical EKF implementations.展开更多
A calculation of the energy loss due to a transition from non-equilibrium to equilibrium state is given. Three different physical systems are considered in this study: connecting an uncharged capacitor to a charged ca...A calculation of the energy loss due to a transition from non-equilibrium to equilibrium state is given. Three different physical systems are considered in this study: connecting an uncharged capacitor to a charged capacitor, emission of a photon from an excited atom, and releasing an object from a compressed spring. In this study, it is shown that a specific fraction of the total energy stored in a non-equilibrium system should be consumed to reach the equilibrium state.展开更多
文摘This work presents a new method for space-based angles-only orbit estimation.The approach relies on the integration of a novel and highly accurate Analytic Continuation technique with a new measurement model for multiple observers for inertial orbit estimation.Analytic Continuation computes the perturbed orbit dynamics,as well as the perturbed state transition matrix(STM),in the inertial frame.A new measurement model is developed for simultaneous measurements using a constellation of low-cost observers with monocular cameras for angles-only measurements.Analytic Continuation and the new measurement model are integrated in an Extended Kalman Filter(EKF)framework,where the Analytic Continuation method is used to propagate the perturbed dynamics and compute the perturbed STM and error covariance,with the measurements obtained via the new measurement model.Two case studies comprising small and large constellations of observers are presented,along with cases of sparse measurements and a study of the computational efficiency of the proposed approach.The results show that the new approach is capable of producing highly accurate and computationally efficient perturbed orbit estimation results compared with classical EKF implementations.
文摘A calculation of the energy loss due to a transition from non-equilibrium to equilibrium state is given. Three different physical systems are considered in this study: connecting an uncharged capacitor to a charged capacitor, emission of a photon from an excited atom, and releasing an object from a compressed spring. In this study, it is shown that a specific fraction of the total energy stored in a non-equilibrium system should be consumed to reach the equilibrium state.