Fig. 1. Diagram of R-FCN network structure

Fig. 2. Diagram of RoI

Fig. 3. Residual structure

Fig. 4. Improved residual block structure

Fig. 5. Splitting diagrams

Fig. 6. Ship detection results of Sentinel-1 images. (a) Picture 1 to be tested; (b) picture 2 to be tested; (c) picture 3 to be tested; (d) original R-FCN detection result of Fig. 6(a); (e) original R-FCN detection result of Fig. 6(b); (f) original R-FCN detection results of Fig. 6(c); (g) detection result of improved Faster R-FCN for Fig. 6(a); (h) detection result of improved Faster R-FCN for Fig. 6(b); (i) detection result of improved Faster R-FCN for Fig. 6(c); (j) detection result of improved R-FC

Fig. 7. Test results

Fig. 8. Ship detection results of GF-3 image. (a) Picture 1 to be tested; (b) picture 2 to be tested; (c) picture 3 to be tested; (d) detection result of improved R-FCN for Fig. 8(a); (e) detection result of improved R-FCN for Fig. 8(b); (f) detection result of improved R-FCN for Fig. 8(c)

Table 1. Statistic table of ship detection results of images with different sizes

Table 2. Statistical table of ship detection results