## 3 Data Analyses
### Experiments and Analyses  
The simulation experiments were conducted with the implemented test system, and the obtained data were analyzed. As shown in Figure 9, the test system accomplished three autonomous flight simulations of target tracking and interception with the pod. According to the designed workflow, the carrier sent the instructions \"pod preparation\", \"simulated launch\", and \"not ready\" one by one to the pod. The pod responded \"self-inspection ok\" to the carrier's instruction \"pod preparation\", as well as the instructions \"simulated launch\" and \"cancel the simulated launch\". Hence, the execution process was followed appropriately. To facilitate data analysis, the interactive instructions and responses between the carrier aircraft and pod were considered as reference. The absolute numbers of the carrier's instructions were adjusted for the convenience of visualization. After issuing the \"preparation\" command, the carrier aircraft sent the initial information to the pod, including the longitude, latitude, altitude, carrier velocity X, carrier velocity Y, carrier velocity Z, pitch angle, heading angle, and roll angle, which were utilized by the pod to establish a navigation coordinate system to realize a simulated autonomous flight upon receiving the \"simulated launch\" command. To ensure the navigation accuracy of the pod during the handover from the midcourse to terminal guidance, the influence of wing deformation and installation error should be considered in the attitude data of the aircraft. The angle information issued by the carrier aircraft is shown in Figure 10, in which the data of the first simulated autonomous flight are enlarged and presented in Figure 11. As shown in Figure 11, the pitch and roll angles of the carrier aircraft changed continuously during the preparation phase, and continuous \"S\"-shaped maneuvers were  
Figure 9: Timing and responses of the test instructions. performed. The velocity information issued by the carrier to the pod is shown in Figure 12. During the demonstrated continuous \"S\"-shaped maneuvers, the northward and westward velocity were considered as changing accordingly, while the skyward velocity did not exhibit obvious fluctuations, which is consistent with the actual characteristics of the flight mechanics of the carrier. When the distance between the target and carrier was 14.95 km, the carrier sent information, such as the distance, with respect to the target intercepted by the airborne radar to the pod. As illustrated in Figure 13, When the pod was 6.5 km away from the target, the battery provided a high-voltage power supply according to the predefined time sequence and transmitted the battery activation signal. As illustrated in Figure 14, when the distances between the carrier and target aircraft were between 0.53 and 0.64 km, the target aircraft turned its flight direction and accelerated to deviate from the carrier. Figure 11: Angles issued by the carrier to the pod during the first simulated autonomous flight. Figure 10: Angle information issued by the carrier to the pod. The launch coordinate system was established based on the evaluation model presented in Section 3.2, whose origin was defined by the location of the pod at the moment when the carrier aircraft issued the \"simulated launch\" instruction. The actual and measured values of the relative location between the carrier and target aircrafts were obtained from Equations (1) and (2), respectively. Consequently, the distance error of the radar tracking and measuring the target in the launch coordinate system is shown in Figure 15. When the target was approaching the airborne radar, starting from 14.95 km inward, the distance measurement error was observed as persistent.