The IG-500N from SBG Systems SAS, Rueil Malmaison, France, is a miniature attitude and heading reference system (AHRS) with a 4 Hz GPS receiver and a barometric sensor. Weighing 8 g, the device combines a set of 3 accelerometers, gyroscopes, and magnetometers; 3 temperature sensors; a barometric pressure sensor; and a GPS receiver. An embedded Extended Kalman filter enables the device to compute drift-free and accurate 3D orientation, velocity, and position, even in a highly dynamic environment, with an output rate up to 100 Hz. Each device is individually calibrated for bias and gain error over the full temperature range. Other effects such as cross-axis, misalignment, or gyro-g effects are also corrected internally.