摘要 |
<p>Methods and apparatus for producing orientation dependent radiation, and orientation detection systems are disclosed. An orientation dependent radiation source directs radiation to an observation area and facilitates a determination of the orientation of the orientation dependent source from the observation area. In particular, the orientation dependent source produces a radiation pattern having one or more detectable centroids that vary in position across an observation surface of the orientation dependent source as observed from the observation area, based on a rotation of the orientation dependent source about one or more axes of rotation. According to various embodiments, the orientation dependent radiation source may include one or more primary radiation sources or secondary sources, such as reflectors. One or more orientation dependent sources may be employed in an orientation detection system according to the invention which includes a radiation sensor located in the observation area to detect the orientation dependent radiation pattern produced by one or more orientation dependent radiation sources. Additionally, the radiation pattern produced by an orientation dependent source may be visibly observable, allowing an observer to qualitatively determine the orientation of the source from the observation area.</p> |