Infrared Earth horizon sensors (EHS) are capable of providing attitude knowledge for satellites in low-Earth orbit, even during periods of eclipse. Attitude information is acquired by detecting Earth’s infrared electromagnetic radiation and, subsequently, determining the region obscured by Earth in the sensors’ fields of view to compute a nadir vector estimation in the satellite’s body frame. D...

Unmanned Aerial Vehicles (UAV’s) are finding increased application in both domestic and military applications. Most end users of UAV’s are not particularly interested in the flying platform itself, but rather in the destination, the timing, the cost and objectives of a particular mission. Many end users have very little training in aircraft flight, including model or remote controlled aircraft....

In this paper, a novel technique for finding a pointby-point (deterministic) attitude solution of a vehicle using Global Positioning System phase difference measurements is presented. This technique transforms a general cost function into a more numerically efficient form by determining three-dimensional vectors in either the body or reference coordinate system. Covariance relationships for the...

The performances of three attitude determination algorithms are compared in this paper. The three methods are the Complementary Filter, a Quaternion-based Kalman Filter and a Quaternion-based Gradient Descent Algorithm. An analysis of their performance based on an experimental investigation was undertaken. This paper shows that the Complementary Filter requires the least computational power; Qu...

The vectorized algorithms for GPS based attitude determination can be equivalent to a two-level optimal estimation problem. In the first level estimation the GPS carrier phase measurements can be converted to the vector observations in a sense of least squares. The second level estimation is the Wahba’s problem which describes how the attitude matrix can be derived from the vector observations....

The GNSS (Global Navigation Satellite Systems) are a valid aid in support of the aeronautic science. GNSS technology has been successfully implemented in aircraft design, in order to provide accurate position, velocity and heading estimations. Although it does not yet comply with aviation integrity requirements, GNSS-based aircraft navigation is one of the alternative means to traditional dead-...