**5. Ablation Study**

In this section, we will show the results of ablation studies to confirm the effectiveness of the proposed GCIM-Block and BABP-Block. Experiments are performed on SSDD.

### *5.1. Ablation Study on GCIM-Block*

5.1.1. Effectiveness of GCIM-Block

Table 4 shows the quantitative results with/without GCIM-Block. The GCIM-Block offers a 1.6% box AP gain and a 1.1% mask AP gain, showing its effectiveness. It can model the global background context information so as to capture spatial long-range dependences of ships, which can enable better background discrimination ability.

**Table 4.** Quantitative Results with and Without GCIM-Block.

