The Flock of Birds (FOB) is a stand alone system and has the following components:
A 1 foot cube transmitting antenna, which is mounted above the center of the CAVE, and sends out the electro-magnetic signals.
1 Extended Range Controller (ERC); the transmitter.
2 receivers, attached to a receiving antenna either on the glasses or wand (if more receiving antennae are used, more receiver boxes are needed).
The FOB is connected to the SGI via ethernet. The FOB is synchronized to a stereo signal that controls the LCD glasses. This prevents the magnetic field of the FOB from causing distortion in the image and also makes interferance with nearby CAVES less obvious. The static accuracy of the FOB has been improved by calibration procedures developed by EVL.