When an aircraft moves under a low carrier-to-noise ratio(CNR) or at a high speed,increasing the sensitivity of global navigation satellite system(GNSS) receiver is a goal quite hard to achieve.A novel acquisition scheme assisted with micro-electro-mechanical-sensor(MEMS) inertial navigation system(INS) is presented to estimate the Doppler caused by user dynamics relative to each satellite ahead of time.Based on tightly coupled GNSS/INS estimation algorithm,MEMS INS Doppler error that can be achieved is first described.Then,by analyzing the mean acquisition time and signal detection probability,the MEMS INS-assisted acquisition capabilities in cold,warm and hot starts are quantitatively determined and compared with the standard GNSS acquisition capability.The simulations and comparisons have shown that:the acquisition time in cold start can be shortened by at least 23 s,the time in warm start can be shortened to 1 s and the acquisition capability is improved 95%,and the reacquisition time in hot start can be shortened by around 0.090 s and the capability can be enhanced 40%.The results demonstrate the validity of the novel method. When an aircraft moves under a low carrier-to-noise ratio (CNR) or at a high speed, increasing the sensitivity of global navigation satellite system (GNSS) receiver is a goal quite hard to achieve. A novel acquisition scheme assisted with micro- electro-mechanical-sensor (MEMS) inertial navigation system (INS) is presented to estimate the Doppler caused by user dynamics relative to each satellite ahead of time. Based on tightly coupled GNSS / INS estimation algorithm, MEMS INS Doppler error that can be achieved is the first described. by analyzing the mean acquisition time and signal detection probability, the MEMS INS-assisted acquisition capabilities in cold, warm and hot starts are quantitatively determined and compared with the standard GNSS acquisition capability. The simulations and comparisons have shown that : the acquisition time in cold start can be shortened by at least 23 s, the time in warm start can be shortened to 1 s and the acquisition capability is improved 95%, and the reacquisition t ime in hot start can be shortened by around 0.090 s and the capability can be enhanced 40%. The results demonstrate the validity of the novel method.