INS/DL/GNSS tightly coupled integrated navigation method under GNSS restricted conditions
In order to meet the accuracy requirements of navigation systems under GNSS restricted conditions,an iner-tial navigation system(INS)/data link(DL)/Global Navigation Satellite System(GNSS)tightly coupled integrated algorithm is proposed.This algorithm corrects the INS error by fusing the pseudo range information of GNSS receiver and wireless ran-ging information of DL positioning with INS information.As long as there are GNSS visible satellites or DL source nodes,information fusion can be carried out,maximizing the use of navigation observations in the scene and improving the quality of navigation information.The experimental results indicated that adding limited satellite observation measurements could improve the accuracy of the navigation system under good data link communication.In the case of weak data link connectiv-ity,the introduction of limited satellite observation measurements enabled the navigation system to continuously output high-precision navigation information.