MINISTRY OF EDUCATION AND TRAINING
MINISTRY OF DEFENSE
ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY
***************
PHAN HONG MINH
RESEARCHING METHODS TO IMPROVE THE
QUALITY OF AN UNDERWATER SENSOR ARRAY
RECEIVING SIGNALS IN SHALLOW WATER AREAS
Specialization : Electronic Engineering
Code No : 9 52 02 03
SUMMARY OF TECHNICAL DOCTORAL THESIS
Ha Noi – 2020
The thesis is completed at:
Academy of military Science and Technology
Scientific Supervisor:
1. Dr Phan Trong Hanh
2. Dr Vu Van Binh
Reviewer 1: Prof. Dr Vu Van Yem
Hanoi University of Science and Technology
Reviewer 2: Assoc. Prof. Dr Do Quoc Trinh
Military Technical Academy
Reviewer 3: Dr. Vu Le Ha
Academy of military Science and Technology
The thesis will be defended before approval committee at :
Time , date month year 2020
This thesis may be found at:
- Library of Academy of Military Science and Technology
- The Vietnam National Library.
LIST OFPUBLICATIONS
1) Phan Hong Minh, Phan Trong Hanh, Luong Thi Ngoc Tu,
“Configuration of hydrophone array based on ICA pre-processing to
enhance accuracy position of multi-targets”, Journal of Military
Research and Technology, No. 48, 04/2017.
2) Phan Hong Minh, Phan Trong Hanh, Vu Van Binh, Nguyen
Cong Dai, “The Solution of configuration 2D hydrophone array based on
beamforming option”, Journal of Military Research and Technology, No.
54, 04/2018.
3) Le Ky Bien, Phan Hong Minh, Tran Hieu Thao, Phan Trong
Hanh, “The solution of signal processing for sonobouy systems detection
and identification based on passive sonar”, The National conference
"High-tech applications in practice" 2018, Journal of Military Research
and Technology, No. Special issue, 08/2018.
4) Phan Hong Minh, Phan Trong Hanh, Vu Van Binh, “Multi-
channels blind deconvolution of shallow underwater signals based on
Feed-Foword neural networks”, Journal of Military Research and
Technology, No. 62, 08/2019.
1
INTRODUCTION
1. Necessity of the thesis
The sea is especially important for national defense and security, for
socio-economic development and integration with the world. All
countries having seas must have their own plans and solutions to protect
the safety of their waters, islands and territorial waters. Safely protecting
coastal, military bases and archipelagos, detecting target identification to
prevent underwater targets from the sea is necessary.
2. Obiectives of the study
Research and develop solutions to improve the signal quality of the
underwater sensor array for sonar systems and passive positioning
devices to enhance the ability to detect and locate targets as sources
underwater sound in the shallow sea.
3. The main results, scientific significance and practical meaning of
the thesis
3.1. The main results
1) Proposed structural model of the retangular acoustic sensor
array, combined with a customized adaptive beamforming solution,
increased the gain of the sensor array.
2) Proposed a model and solution for complex underwater signal
processing on the basis of combining independent component analysis
(ICA) and multi-channel blind analysis (MBD) to improve SNR ratio in
shallow water areas.
3.2. Scientific significance and practical meaning of the thesis.
The research to improve the quality of the underwater sensor array
for sonar systems, passive positioning devices for underwater acoustic
emission targets is carried out on the basis of structural solutions and
signal processing for shallow waters is to solves scientific and practical
requirements.
Research results of the thesis with the proposal of a solution of array
structure and adaptive beamforming and a solution of complex acoustic
signal processing based on the combination of two signal processing
techniques ICA and MBD will contribute more theoretically to the field
of hydrodynamic positioning. At the same time, these research results
are related to the conditions and characteristics of Vietnam's territorial
waters, so it will be a good basis and orientation when designing sonar
systems or underwater positioning devices in Vietnamese.
2
CHAPTER1: UNDERWATER SENSOR ARRAY AND PROBLEM
TO IMPROVE QUALITY ARRAY IN THE SHALLOW WATER
1.1 Overview of underwater sensor array
1.1.1 Model of sensor array
The sources of interest in sonar and ultrasound are the
narrowband and wideband applications that satisfy the wave
transmission equation in [31], [37], and their spatial properties can be
independently separated. Therefore, the measurement of the 𝑧 𝑟 ,𝑡 is
stimulated by negative sources that can determine the time-space
response 𝑥 𝑟 ,𝑡 . The vector 𝑟 is the relative position of the sensor and
the sound source, t is the time.
Figure 1.1 Space-Time Model receiving signal of sensor array
Response output 𝑥 𝑟 ,𝑡 is convolution of 𝑧 𝑟 ,𝑡 and response of
sensor array ℎ 𝑟 ,𝑡 .
𝑥 𝑟 ,𝑡 = 𝑧 𝑟 ,𝑡 ⊗ℎ 𝑟 ,𝑡
(1.1)
There 𝑧 𝑟 ,𝑡 is defined are input of receiver, and is convolution of
acoutic souce parameter 𝑦 𝑟 ,𝑡 with underwater environment Ψ 𝑟 ,𝑡 .
(1.2)
1.1.2 Sensor array and underwater passive sonar system
Model of structure system
The sonar system is a system of devices that determine the
position of the sound source in the space under the sea surface.
Depending on the application and different characteristics, the system