**6. Conclusions**

In this paper, a sonar sensor system provided by a Doppler measurement association method was proposed for enhancing the performance of multi-target tracking in a noisy jamming environment. In the Doppler measurement association scheme, the target velocity measurements are utilized for calculating the observation likelihood, which are an important part for distinguishing true measurements from phony targets or clutter measurements. The sonar system improved by the proposed scheme has a tiny influence on system stability but offers a significant decrease in the amount of confirmed false targets. Meanwhile, the target resolution capability of the system provided by the LMIPDA-DDA algorithm is obviously improved, which can be realized without equipping a nonlinear filter bank. In the clutter environment, the traditional method that uses location-only component obtain a substantial NCTT, while the proposed method that combine target velocity components do not. The usefulness of the enhanced DDA scheme has been verified in a sea clutter environment.

**Author Contributions:** Conceptualization, Y.Y. and J.Z.; methodology, Y.Y.; software, J.Z.; validation, Y.Y., J.Z. and L.W.; formal analysis, Y.Y.; investigation, Y.Y.; resources, J.Z.; data curation, J.Z.; writing—original draft preparation, Y.Y.; writing—review and editing, J.Z.; visualization, Y.Y.; supervision, L.W.; project administration, L.W.; funding acquisition, Y.Y.

**Funding:** This work was supported by the National Natural Science Foundation of China (61761019, 61861017, 61861018, 61862024) and the Natural Science Foundation of Jiangxi Province (Jiangxi Province Natural Science Fund) (20181BAB211014, 20181BAB211013) and Foundation of Jiangxi Educational Committee of China (GJJ180352).

**Conflicts of Interest:** The authors declare no conflict of interest.
