Abstract: A device for flagging an object buried in the snow includes a flag housed in a pouch, and held within the pouch by a closure mechanism such as a snap closure or a hook-and-loop closure. The flag is attached to a tether by means of an encircling element that passes around the closure mechanism (for example the encircling element could comprise a loop on the pouch end of the tether). As the encircling element is tugged on sharply, it forces the closure mechanism open, which allows the flag to exit the pouch, unfurling as it goes. The flag is attached via the tether to the object to be flagged, such as a ski, while the pouch remains fastened to a base object such as a ski boot. The system may also be used to locate avalanche victims, in which case the flag is attached to the person, thus providing a visual clue to the location of the victim buried below the surface of the avalanche.

Abstract: Disclosed is a wireless instrument tracking system. The wireless instrument tracking system is used for determining the location of at least one point relative to the instrument in a three-dimensional space relative to a three-dimensional coordinate tracking system. Advantageously, a first wireless instrument can be placed into the optical field with the wireless instrument including a wireless receiver and at least one optical position indicator. The optical position indicator is typically light emitting diodes (18) and communicates with corresponding measurement sensors (30) across a wireless optical link. The wireless optical link is time multiplexed with repetitive time frames divided into time slots. Each LED (18) emits an infrared signal or flashes in a respective time slot of a time frame. The measurement sensors (30) are preferably CCD cameras.

Abstract: An assembly adapted to emit electromagnetic radiation made up of an emitter of electromagnetic radiation; a non-reflective ceramic support for the emitter; a substantially transparent crown mounted on the support to define and enclose a space that houses the emitter; and leads attached to the emitter through the support. The combination of the non-reflective support and the transparent crown, and the location of the emitter in the enclosed space enables the emitter to emit electromagnetic radiation in a conical radiation pattern. The radiation pattern appears to have a centroid. This centroid appears to be in a more constant spatial position regardless of the viewing angle as compared with the apparent position of this centroid with other assemblies.

Abstract: Improved point source electromagnetic radiation emitters including a dispersing element that radiates electromagnetic radiation over a very wide conical angle of approaching about 180.degree.. This light dispersing element can be in any one or more of several illustrated forms such as a light diffusing spherical or hemispherical element, a planar diffusing plate, a tapered light guide, a plano-concave lens, a convex mirror, a light pipe with a large numerical aperture, or the like. The emitter of this invention may be fixed to an object and tracked in a 3-dimensional volume by a system using electro-optical position sensors in order to determine the spatial location of the emitters and therefore to determine, by geometry, the position and orientation of the object. The electromagnetic radiation generator is preferably disposed remote from the emitter and is electrically and magnetically isolated from the emitter. A common optical fiber provides transmission of the radiation from the generator to the emitter.

Abstract: Improved point source electromagnetic radiation emitters including a dispersing element that radiates electromagnetic radiation over a vary wide conical angle of approaching about 180°. This light dispersing element can be in any one or more of several illustrated forms such as a light diffusing spherical or hemispherical element, a planar diffusing plate, a tapered light guide, a piano-concave lens, a convex mirror, a light pipe with a large numerical aperture, or the like. The emitter of this invention may be fixed to an object and tracked in a 3-dimensional volume by a system using electro-optical position sensors in order to determine the spatial location of the emitters and therefore to determine, by geometry, the position or orientation of the object. The electromagnetic radiation generator is preferably disposed remote from the emitter and is electrically and magnetically isolated from the emitter. A common optical fiber provides transmission of the radiation from the generator to the emitter.