## 4 Simulation and Result
### General Deceptive Scene Case  
In this section, the HDE algorithm is applied to generate an extended fake scene. The jamming object is a nonlinear SAR with the trajectory deviation shown in Figure 7 and its parameters shown in Table 1. The deceptive template is constructed based on the SAR image acquired by TerraSAR-X in the spotlight SAR mode [37], which can take advantage of the large scene, sharp contrast, and high-resolution characteristics of the image in this mode  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Scatters**} & \multicolumn{2}{c}{**P1**} & \multicolumn{2}{c}{**P2**} & \multicolumn{2}{c}{**P3**} & \multicolumn{2}{c}{**P4**} & \multicolumn{2}{c}{**P5**} & \multicolumn{2}{c}{**P6**} & \multicolumn{2}{c}{**P7**} & \multicolumn{2}{c}{**P8**} & \multicolumn{2}{c}{**P9**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**STD**} \\ \hline \multirow{6}{*}{Azimuth} & RS & 0.87 & 0.87 & 0.85 & 0.87 & 0.87 & 0.85 & 0.87 & 0.87 & 0.85 & 0.86 & 0.01 \\  & BA & 0.87 & 0.87 & 0.85 & 0.87 & 0.87 & 0.85 & 0.87 & 0.87 & 0.85 & 0.86 & 0.01 \\  & HDE & 0.87 & 0.87 & 0.86 & 0.87 & 0.87 & 0.86 & 0.87 & 0.87 & 0.86 & 0.87 & 0.01 \\  & MILPO(m) & & 0.29 & \(-\)0.04 & 0.34 & 0.29 & \(-\)0.04 & 0.34 & 0.29 & \(-\)0.04 & 0.34 & 0.20 & 0.17 \\  & IRWB(\%) & & 0.15 & 0.32 & 0.53 & 0.15 & 0.32 & 0.52 & 0.15 & 0.32 & 0.53 & 0.33 & 0.16 \\ \cline{2-11}  & \multirow{3}{*}{PSLR(dB)} & RS & \(-\)13.26 & \(-\)13.27 & \(-\)13.28 & \(-\)13.27 & \(-\)13.27 & \(-\)13.28 & \(-\)13.27 & \(-\)13.27 & \(-\)13.28 & \(-\)13.27 & 0.01 \\  & SA & \(-\)13.27 & \(-\)13.27 & \(-\)13.28 & \(-\)13.27 & \(-\)13.27 & \(-\)13.28 & \(-\)13.26 & \(-\)13.27 & \(-\)13.28 & \(-\)13.27 & 0.01 \\  & HDE & \(-\)12.28 & \(-\)13.48 & \(-\)10.91 & \(-\)12.27 & \(-\)13.  
To compare and illustrate the focusing ability of the algorithm. First, the HDE algorithm is used to generate the same fake scene as the deceptive jamming template for comparison to evaluate the jamming effect. The imaging processing of the interfering signal does not involve the actual echoes of the scene. The actual scene generated by the RS and the fake scene image generated by the HDE algorithm, as shown in Figures 12 and 13.  
From the overall views of the radar image, the jamming image of the HDE algorithm is approximately consistent with the original SAR image. To find out the difference in details, the 1500 m \(\times\) 1800 m area shown in the red box is enlarged, i.e., Figure 14a,b, and the structural similarity SSIM is used to measure the difference between the two images and evaluate the quality of jamming radar image. The measured value of structural similarity (SSIM) is 0.95, indicating that the jamming image of the HDE algorithm is very similar to the original SAR image. The results show that the HDE algorithm can well preserve the  
Figure 12: Actual scene generated using RS. Parts of the image marked by rectangular red box is enlarged and shown in Figure 14a.  
Figure 13: Fake scene generated using HDE. Parts of the image marked by rectangular red box is enlarged and shown in Figure 14b.  
deceptive electromagnetic features such as false scene points, lines, surfaces, and brightness when jamming nonlinear-trajectory SAR.  
Then deceptive jamming templates for islands and ship groups are obtained from other SAR images with sizes of 2500 m \(\times\) 2000 m and 2000 m \(\times\) 3500 m, respectively. In addition, the jamming signal is generated by the HDE algorithm to jam the actual coastal scene in Figure 15a. Figure 15b shows the result of jamming imaging, with fake islands and groups of ships set beyond the coastline. Compared with the actual scene in Figure 15a, the fake pier scene is well-focused and difficult to distinguish from the actual scene. The results verify the effectiveness of the proposed algorithm.