International Core Journal of Engineering 2020-26 | Page 214

1 1 0.8 0.8 0.6 0.4 0.2 0.6 0.4 0.2 0 1 0 1 0.5 1 0.5 1 0.5 0 -0.5 -1 0 -0.5 -0.5 -1 K =sin( T )cos( I ) 0.5 0 0 -0.5 -1 K =sin( T )cos( I ) [ =sin( T )cos( I ) (a) -1 [ =sin( T )cos( I ) (b) Fig. 4. Simulations for normalized point source. (a) Normalized point source in Cornwell algorithm ; (b) Normalized point source in he proposed method. Tikhonov Regularization Reconstruction Brightness Tikhonov Regularization Reconstruction Brightness 1 1 160 200 0.8 0.8 140 0.6 0.6 120 150 0.4 0.4 100 0.2 0.2 80 0 -0.2 -0.2 -0.4 40 -0.4 -0.6 20 -0.6 -0.8 0 -0.8 -1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 100 0 60 -1 -1 1 (a) 50 0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 (b) Fig. 5. Reconstruction Brightness; (a) Reconstruction Brightness in Cornwell algorithm ; (b) Reconstruction Brightness in UCA-MMA. reconstruct the brightness temperature. The original scene is shown in Fig. 6. The simulation results shows the feasibility of proposed method. The original two-dimensional Brightness 1 0.8 180 0.6 160 0.4 140 0.2 120 0 100 -0.2 80 -0.4 60 -0.6 40 -0.8 20 -1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 IV. C ONCLUSION In this paper, a novel modified objective function is proposed, which uses the minimum distance of adjacent elements as objective function and has advantages in meeting the minimum element spacing constraint and forming a uniform separations. Improved simulated annealing algorithm (SA) has been applied to the proposed method. Several comparisons of numerical results have been obtained to demonstrate the flexibility and outperformance of this new proposed approach. 1 A CKNOWLEDGMENT Fig. 6. Original scene. The Author would like to thank the reviewers for their constructive and helpful comments. Normalized point source obtained by Cornwell algorithm and he proposed method are shown in Fig.4. From the results, it can be shown that for imaging the same target with the same number of antennas, the side lobe of the point-source image obtained by the proposed method is slightly improved. This work was supported by the National Natural Science Foundation of China under Grant 61671217. Corresponding author is Xueqing Yang, School of Electronic Informationand Communications, Huazhong University of Science and Technology, Wuhan 430074, China. Simulation results of reconstruction brightness of extended source have been shown in Fig. 5. For this simulation, the number of elements is thirty. The extended source is a 64*64 pixel image. G matrix was used to R EFERENCES [1] 192 C. S. Ruf, C. T. Swift, A. B. Tanner, and D. M. Le Vine,