| 摘要 |
<p>A target is provided having a retroreflector. A body is provided having a spherical exterior portion, the body containing a cavity. The cavity is sized to hold the retroreflector, the cavity open to the exterior of the body and having at least one surface opposite the opening, the retroreflector at least partially disposed in the cavity, wherein the retroreflector and at least one surface define a space therebetween. A transmitter is configured to emit an electromagnetic signal. A first actuator is configured to initiate emission of the electromagnetic signal, wherein the transmitter and the first actuator are affixed to the body.</p> |
