CompuServe Messages

John, The most direct way to tell the helmet orientation is with an IMU – gyros set at precise angles to each other that give angular accelerations and linear acceleration measuerments. A processor then integrates those accelerations to compute velocity and postition. Expensive technology that requires constant calibration. (Unless you go with the HRG – Hemispherical Resonating Gyro a sealed peice of wine glass shaped glass that is excited and whose resonance pattern is monitored for acceleration effects – where talking several hundred K per copy!) wmc