Passive double satellites/doppler combined navigation technology

The "BD-1 system usually adopts active positioning method, which posesses some shortages in the system application, such as limited number of user. The restriction of implementing passive positioning is the lack of enough satellites. A passive combination navigation technology called passive double satellites/Doppler combined navigation technology is presented in this paper. The principle of the passive double satel-lites/Doppler combined navigation orientation is analyzed and designed. A simulation test is conducted to e-valuate this combined navigation technology. The result shows that this technology is able to reduce Doppler navigation positioning error, improve navigation accuracy, and implement passive positioning based on "BD-1" system. Finally, the feasibility of this method is analyzed as well as its application prospect.