In this paper a constrained relative attitude determination solution of a formation of two vehicles is considered and the effect of constraint violation on the estimation error is studied. The solution for the relative attitude between the two vehicles is obtained only using line-of-sight measurements between them and a common (unknown) object observed by both vehicles. The solution represents ...

A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated using an Euler angles (small libration version)...

Global Navigation Satellite Systems (GNSS)-based attitude determination has been recognized as a significant field of study in numerous ground, marine and airborne applications. This paper investigates the feasibility of precise attitude determination using a GNSS receiver capable of antenna array processing. The ability to determine attitude parameters by employing only a single satellite sign...

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 ...

For many biomechanical applications it is necessary to determine the parameters which describe the transformation of a rigid body from one reference frame to another. These parameters are a scaling factor, an attitude matrix, and a translation vector. The paper presents a new procedure for the determination of these parameters incorporating the work of Arun et al. [IEEE Trans. Pattern Anal. Mac...

A new navigation system for small size Remotely Piloted Aircraft Systems (RPAS) is presented, which is based on Global Navigation Satellite System (GNSS), Micro-Electro-Mechanical System (MEMS) based Inertial Measurement Unit (IMU), Vision Based Navigation (VBN) and other low-cost avionics sensors. The objective of this research is to design a compact, lightweight and relatively inexpensive Nav...

Scientific balloons have been launched in Japan by ISAS/JAXA since 1965, and Prof. Hashimoto’s group has been developing a micro-gravity experiment system, called BOV (Balloon-based Operation Vehicle), which uses free-fall from a high-altitude balloon. Flight experiments of BOV were carried out in 2006 (BOV1) and in 2007 (BOV2), when a fine micro-gravity environment had been established success...

Objectives. Pregnant women, referred because of an increased risk of fetal Down syndrome, who underwent an invasive prenatal procedure were offered a choice between karyotyping and rapid targeted testing. This study aims to assess women's attitudes and experiences towards what option to choose. Methods. A retrospective multicentre survey (2008-2010) was conducted among 1370 women. General quest...

GPS attitude outputs or carrier phase observables can be effectively utilized to compensate the attitude error of the strapdown inertial navigation system. However, when the integer ambiguity is not correctly resolved and/or a cycle slip occurs, an erroneous GPS output can be obtained. If the erroneous GPS output is applied to the attitude determination GPS/INS (ADGPS/INS) integrated navigation...

Carrier phase measurements are primary observations for GPS attitude determination. Although the satelliterelated errors can be virtually eliminated by forming single differences, the baseline-related errors, such as line biases, are still present in the single-differenced carrier phase measurements. It is, therefore, difficult to resolve the single-differenced integer ambiguities due to the li...