Wind tunnel engineers require measurements of position and orientation of aerospace models under test conditions. The measurement technique must be non-contact, nonintrusive and have a high sample rate. Videometric techniques based on multiple, synchronised CCD cameras can supply position and orientation data at 30Hz or 60Hz with acceptable accuracies. This paper describes a data acquisition sy...

This paper presents a computationally-fast inverse dynamics model based on unit quaternion orientation representation for use in the generation of unmanned aircraft trajectories when the flight envelope may include all flight path orientations, a necessary attribute for aerobatics or unmanned air-to-air combat vehicles. The model removes the inherent singularities in Euler-angle attitude repres...

In order to measure the perceived direction of "up", subjects judged the three-dimensional shape of disks shaded to be compatible with illumination from particular directions. By finding which shaded disk appeared most convex, we were able to infer the perceived direction of illumination. This provides an indirect measure of the subject's perception of the direction of "up". The different cues ...

Flight experience is one of the factors that influences initial orientation of displaced homing pigeons (Columba livia). Prior studies showed a systematic dependence of initial orientation on previously flown direction. Using GPS data loggers, this study sought to examine the effect of previous directional training of 40 homing pigeons when they were released over the sea, in the absence of pro...

A low-cost aerial platform represents a flexible tool for acquiring high-resolution images for ground areas of interest. The geo-referencing of objects within these images could benefit civil engineers in a variety of research areas including, but not limited to, work zone management, traffic congestion, safety, and environmental impact studies. During the Phase II effort, a Remotely Controlled...

INTRODUCTION The human balance system comprises of the semi-circular canals, which sense rotation of the head, and the otoliths, which act as linear accelerometers. On Earth, the otoliths sense the constant linear acceleration of gravity, and this information is used by the brain to determine the spatial vertical, and the orientation of the head with respect to the vertical. This information is...

We present results from in-flight calibration of the High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory. Basic grating assembly parameters such as orientation and average grating period were measured using emission line sources. These sources were also used to determine the locations of individual CCDs within the flight detector. The line response function (L...

Flying birds rely on visual cues for retinal image stabilization by negating rotation-induced optic flow, the motion of the visual panorama across the retina, through corrective eye and head movements. In combination with vestibular and proprioceptive feedback, birds may also use visual cues to stabilize their body during flight. Here, we test whether artificially induced wide-field motion gene...

Most insect migrants fly at considerable altitudes (hundreds of meters above the ground) where they utilize fast-flowing winds to achieve rapid and comparatively long-distance transport. The nocturnal aerial migrant fauna has been well studied with entomological radars, and many studies have demonstrated that flight orientations are frequently grouped around a common direction in a range of noc...