![doppler max 6 doppler max 6](https://ecgwaves.com/wp-content/uploads/2019/11/pulsed-wave-doppler-ultrasound-echocardiography-pw-825x1024.jpg)
![doppler max 6 doppler max 6](https://static-01.hindawi.com/articles/ijap/volume-2014/875345/figures/875345.fig.006.jpg)
In case of the low-Doppler target, the target echo is located in the mainlobe and sidelobe of the beamformer, so additional algorithm is required to suppress the reverberation. Īlthough the reverberation can be addressed by the beamformer, adequate suppression of the reverberation is not achieved. Conventional target detection algorithms, including the matched filter, are sensitive to reverberations, and extensive research has been conducted to improve detection in this condition. However, in addition to reflection from the target, the received signal contains reverberations caused by reflection from scatterers. Moreover, an experiment is conducted using reverberation measured from an ocean, and the results show that the proposed algorithm can effectively suppress reverberation and enhance detection performance in practical settings.Īctive sonar is used to detect a target under water using a reflected ping. Experiments using simulated reverberations are performed to evaluate the proposed algorithm, and the results show an enhancement in the signal-to-noise ratio by 6–15 dB, as well as in the detection probability at several signal-to-reverberation ratios. We also derive constraints on temporal continuity and temporal length to estimate bases for the target echo. To extract the target echo signal mixed with reverberations, the bases for the target echo and the reverberation are independently defined, and different constraints are applied for their corresponding estimation. In this paper, we propose an algorithm for the reverberation suppression of continuous wave signals using non-negative matrix factorization. Detection becomes more difficult if targets have low-Doppler frequency and are located near the reverberation band, especially in an environment with low signal-to-reverberation ratio. In active sonar systems, the detection of echo from targets can deteriorate due to reverberation.