Abstract: The integr at ion of GPS receivers and micro-miniature inertial sensors character ized by its small size, lightweight and low cost can overcome their own shortcomings, avoid the positioning err or accumulated with the gr owingtime, and impr ove t he anti-interference abilit y of the system. The decoupled state and bias estimation and bias feedback compensation are used on the basis of the open Kalman filter ing structure. Bi-GPS r eceivers ar e applied to measure the azimuth angle in terms of initial alignment of the integrated system. Vehicle tests show that t he positioningaccuracy of the prototype is about the same to the GPS, and is pr ovided with a quite good repeatability. Especially,when GPS r eceivers were not locked in synchronism for a short time, the system would st ill keep the high positioning accuracy. T hen the reliability of the system has been increased.

Key words: micro-miniature inertial measurement system, global positioning system, integrated system