In a global navigation satellite system (GNSS), external velocity aiding from the inertial navigation system (INS) is able to boost the anti-jamming performance in terms of the jamming-to-signal ratio (J/S). When the external velocity aiding is injected from the INS, the time bias of the loop filter can be set zero. The external velocity aiding requires knowledge of the vehicle attitude, such as position, velocity, and acceleration. In order to verify the J/S performance of the external INS-aided velocity aiding algorithm, the test simulator, that must inject the virtual position, velocity, and acceleration of the GNSS vehicle, should be required. In this paper, we design and verify the implemented test simulator of the INS information insertion software. We define a data interface control document (DICD) between the GNSS and the implemented software to provide the INS information to the GNSS. The DICD must include the position, velocity, and acceleration of the GNSS vehicle. Additionally, we insert the measurement noise such as the acceleration noise into the INS data to test real circumstances of the INS-aided GNSS. From the comparison between real-logged INS data and the simulated INS data generated by the INS simulation software, we verify that the injected INS data can be used to achieve the same results with real environment conditions. The experimental results provide that the INS simulation software can verify the J/S performance of the GNSS through the external velocity aiding. In the experimental test results of the INS injection data with and without random acceleration errors, we can show that the external velocity aiding improves the J/S performance with the GPS L1 C/A, GPS L2C, and GLONASS L1 C/A codes through the implemented INS simulation software.

Keywords: INS simulation software, INS-aided GNSS systems, jamming-to-signal ratio