A system for determination of kinematics of a moving object comprising: a sensor producing angular data for the object at a number of observation times, a state initialization unit, receiving angular data from the sensor and on basis thereof determining a first kinematic state of the object, and a tracking filter having a prediction unit, arranged to determine a predicted kinematics state of the object on bases of a kinematic model of the object, wherein the kinematic model comprises a guidance law locked on a known position, and at least one previously determined kinematic state of the object, and a state updating unit, receiving angular data from the sensor and the predicted kinematic state of the object, and on basis thereof determining an updated kinematic state of the object.