Calculating the WCET of mission-critical satellite applications is a challenging issue. The European Space Agency is currently undertaking the CryoSat mission, consisting of a radar altimetry satellite to be launched in 2005. This paper describes the challenges and the first experimental results of calculating the WCET of the Control and Data Management Unit (CDMU) subsystem of the satellite. T...

Satellite attitude accuracy is an important factor affecting the geometric processing accuracy of high-resolution optical satellite imagery. To address the problem whereby the accuracy of the Yaogan-24 remote sensing satellite's on-board attitude data processing is not high enough and thus cannot meet its image geometry processing requirements, we developed an approach involving on-ground attit...

This paper presents a method for on-orbit calibration of photodiodes for sun sensing in an attitude determination system. The calibration estimates the scale factors and alignment angles of the photodiodes, resulting in higher attitude determination accuracy than achieved with the pre-flight calibration parameters. The calibration is implemented with an extended Kalman filter to simultaneously ...

This study focuses on the development of a precise attitude control system for small satellites. In general, conventional methods used for attitude control in standard-sized satellites are not applicable to small satellites because of constraints of power consumption, space requirements, and mass. In addition, small satellites are more greatly affected than standard-sized satellites by attitude...

• Attitude control – usually autonomous in satellite missions running in a dedicated processor. Its development and testing requires particular conditions. Its development and testing requires particular conditions. For instance, the gravity and air resistance are variables that overcome the effects which disturb the spacecraft attitude on orbit. For this reason, the use of a set of software sy...

Global navigation satellite systems (GNSS) are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM) to search for integer ambiguity, and ...

An algorithm is developed for estimating the motion (relative attitude and relative position) of large pieces of space debris, such as failed satellite. The algorithm is designed to be used by a debris removal space robot which would perform six degreeof-freedom motion control (control its position and attitude simultaneously). The information required as feedback signals for such a controller ...

Received Jul 5, 2014 Revised Nov 11, 2014 Accepted Nov 22, 2014 In this paper, an algorithm was presented to control the satellite attitude in orbit in order to reduce the fuel consumption and increase longevity of satellite. Because of proper operation and simplicity, fuzzy controller was used to save fuel and analyze the uncertainty and nonlinearities of satellite control system. The presente...