WO2022166097A1 - Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine - Google Patents

Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine Download PDF

Info

Publication number
WO2022166097A1
WO2022166097A1 PCT/CN2021/104223 CN2021104223W WO2022166097A1 WO 2022166097 A1 WO2022166097 A1 WO 2022166097A1 CN 2021104223 W CN2021104223 W CN 2021104223W WO 2022166097 A1 WO2022166097 A1 WO 2022166097A1
Authority
WO
WIPO (PCT)
Prior art keywords
scan sonar
signal
receiving array
imaging
mode
Prior art date
Application number
PCT/CN2021/104223
Other languages
English (en)
Chinese (zh)
Inventor
刘佳
许枫
苏仁聪
安旭东
Original Assignee
中国科学院声学研究所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中国科学院声学研究所 filed Critical 中国科学院声学研究所
Publication of WO2022166097A1 publication Critical patent/WO2022166097A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/89—Sonar systems specially adapted for specific applications for mapping or imaging
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
    • G01S15/50—Systems of measurement, based on relative movement of the target
    • G01S15/58—Velocity or trajectory determination systems; Sense-of-movement determination systems

Definitions

  • the invention belongs to the technical field of underwater target detection and positioning, and in particular relates to a multi-mode imaging method for underwater targets of side scan sonar.
  • the traditional method of target positioning based on side scan sonar is that when the side scan sonar is working, the side scan sonar forms two narrow beams perpendicular to the heading direction, and reflects the topographic characteristics of the seabed through the change of the echo intensity of the underwater target. ;
  • the bright spots and acoustic shadows caused by the small target echoes are the main features for underwater target detection.
  • the conventional side-scan sonar scans, the acoustic image formed is a one-pass imaging, which is easily affected by the mechanical movement of the carrier, which causes or produces the distortion of the acoustic image of the target, and the detection rate and recognition rate are low, and the target to be tested cannot be realized. detection problem.
  • the present invention proposes a multi-mode imaging method for an underwater target of a side scan sonar, the method comprising:
  • the side-scan sonar receiving array is divided into multiple primitives, each of which has a separate lead to form an independent primitive, and each primitive receives a single beam signal; during the navigation of the ship, the side-scan sonar is aimed at a certain sea area. Scanning, transmitting multi-beam signals at different angles;
  • the single-beam imaging mode is adopted to process the single-beam signals received by all the elements in the side-scan sonar receiving array to obtain the single-beam imaging sonogram;
  • the parallel beam imaging mode is used to process the single beam signals received by all the elements in the side scan sonar receiving array to obtain the parallel beam imaging sonogram;
  • the fan-beam imaging mode is always used to process the single-beam signals received by all the primitives in the side-scan sonar receiving array to obtain the fan-beam imaging sonogram.
  • the method further includes: according to different speed of the ship, firstly obtain the result of observing the suspected target through the single-beam imaging acoustic image or the parallel beam imaging acoustic image, and then obtain the result of observing the suspected target through the fan-shaped beam imaging acoustic image
  • Target fine observation results according to the obtained observation suspected target results and target fine observation results, determine the position of the target to be measured in the sea area, and realize the detection of the target to be measured.
  • the single-beam imaging mode is used to process the single-beam signals received by all the primitives in the side-scan sonar receiving array to obtain a single-beam imaging sonogram; the specific process is:
  • the single-beam signals received by all the elements of the side-scan sonar receiving array are superimposed and processed by near-field focusing.
  • the beam data Beam 0 (t) is obtained:
  • i is the number of primitives
  • N is the number of primitives
  • s i (t) is the single beam signal received by the i-th element:
  • A is the signal amplitude of the single beam signal received by the ith element
  • f is the signal frequency of the single beam signal received by the ith element, is the received signal phase
  • the parallel beam imaging mode is used to process the single beam signals received by all the primitives in the side scan sonar receiving array to obtain a parallel beam imaging sonogram; the specific process is:
  • the primitive domain signals received by all the primitives of the side-scan sonar receiving array are processed to obtain Parallel beam domain signal model
  • X(t) is the pre-beam vector matrix
  • a is the signal steering vector matrix composed of all the elements of the side-scan sonar receiving array
  • S(t) is the matrix composed of all the elements of the side-scan sonar receiving array
  • N (t) is the noise and interference signal matrix composed of all the elements of the side-scan sonar receiving array
  • ⁇ N is the time delay of the received signal between the ith primitive and the reference primitive;
  • f 0 is the operating frequency;
  • j is the imaginary unit;
  • ⁇ s ⁇ , ⁇ (- ⁇ H , ⁇ H );
  • Equation (3) When considering simple parallel multi-beams, that is, when the beam steering angle of each beam is 0 degrees, and without considering the noise and interference signal N(t), the output of each beam degenerates into the accumulation of several primitive data, then Equation (3) can be simplified as:
  • X(t) [x 1 (t),x 2 (t),x 3 (t)...x j (t)];
  • x j (t) is the j-th pre-beam vector in X (t);
  • s i (t) is the single-beam signal received by the i-th element;
  • the parallel beam imaging sonogram is drawn.
  • the fan beam imaging mode is used to process the signals received by all the primitives in the side scan sonar receiving array to obtain high frequency fan beam data; the specific process is:
  • X(t) 1 is the sector beam vector matrix
  • a 1 is the sector-shaped signal steering vector matrix composed of all the elements of the side-scan sonar receiving array
  • S(t) 1 is composed of all the elements of the side-scan sonar receiving array Sector matrix, that is, the complex envelope of all elementary signal, CW signal or chirp signal
  • N(t) 1 is the noise and interference sector signal matrix composed of all elementary elements of the side-scan sonar receiving array
  • x M (t) is the fan beam vector of the Mth primitive
  • s i (t) 1 is the fan beam signal received by the i-th element
  • Conventional side-scan sonar achieves narrow beams in the horizontal direction, and realizes landform or target sound map through the mechanical movement of the towed body or carrier, which is easily disturbed by mechanical movement, especially when the towed rope is shorter or the ship is fixedly installed, etc. It is more likely to be disturbed by shaking caused by wind and waves,
  • the present invention obtains a more flexible imaging method through multi-mode imaging methods such as single beam, parallel multi-beam and fan-shaped multi-beam, and obtains the target imaging effect without mechanical interference through fan-shaped multi-beam imaging .
  • the conventional imaging method is one-pass imaging, that is, only one effective sound image of the target can be obtained in one track, the amount of information is limited, and the detection and recognition effect is limited.
  • the present invention can obtain more information through multi-frame imaging correlation through multi-mode imaging methods such as single beam, parallel multi-beam and fan-shaped multi-beam, and can complete the rough detection of the target. Then assist target recognition.
  • FIG. 1 is a schematic diagram of a single-beam imaging mode used in a multi-mode imaging method for an underwater target of a side-scan sonar of the present invention
  • FIG. 2 is a schematic diagram of a parallel beam imaging mode used in a multi-mode imaging method for an underwater target of a side-scan sonar of the present invention
  • FIG. 3 is a schematic diagram of a fan beam imaging mode used in a multi-mode imaging method for an underwater target of a side-scan sonar of the present invention
  • FIG. 4 is a schematic diagram of a single-beam imaging acoustic image obtained in an embodiment of a side-scan sonar underwater target multi-mode imaging method of the present invention
  • FIG. 5 is a schematic diagram of a fan beam imaging acoustic image obtained in an embodiment of a side scan sonar underwater target multi-mode imaging method of the present invention
  • FIG. 6 is a flow chart of a multi-mode imaging method for an underwater target of a side scan sonar according to the present invention.
  • the present invention provides a multi-mode imaging method for underwater targets of side-scan sonar.
  • the method of the present invention aims to solve the problem that the acoustic image formed by the conventional side-scan sonar during scanning is a one-pass imaging, which is easily affected by the carrier machinery. Due to the limited amount of information and the limited ability of target detection and recognition, the design of multi-element receiving array is adopted, and the signal of each array element is fully utilized, and the mechanical movement of the carrier is combined with the array phase control technology. At the same time, multi-mode imaging detection in multi-mode imaging modes of single-beam imaging, multi-parallel beam imaging and fan-beam imaging can be realized, which can meet the high detection and recognition performance under high-speed motion and severe carrier attitude changes.
  • the present invention provides a multi-mode imaging method for an underwater target of a side scan sonar, which specifically includes:
  • the side-scan sonar receiving array is divided into multiple primitives, each of which has a separate lead to form an independent primitive, and each primitive receives a single beam signal; during the navigation of the ship, the side-scan sonar is aimed at a certain sea area. Scanning, transmitting multi-beam signals at different angles;
  • the single-beam imaging mode is adopted to process the single-beam signals received by all the elements in the side-scan sonar receiving array to obtain the single-beam imaging sonogram;
  • the single unit received by all the elements of the side-scan sonar receiving array
  • the beam signals are superimposed and near-field focused to obtain the beam data Beam 0 (t):
  • i is the number of primitives
  • N is the number of primitives
  • s i (t) is the single beam signal received by the i-th element:
  • A is the signal amplitude of the single beam signal received by the ith element
  • f is the signal frequency of the single beam signal received by the ith element, is the received signal phase
  • the parallel beam imaging mode is used to process the single beam signals received by all the elements in the side scan sonar receiving array to obtain the parallel beam imaging sonogram;
  • X(t) is the pre-beam vector matrix
  • a is the signal steering vector matrix composed of all the elements of the side-scan sonar receiving array
  • S(t) is the matrix composed of all the elements of the side-scan sonar receiving array, namely The complex envelope of all primitive signals, CW signal or chirp signal
  • N(t) is the noise and interference signal matrix composed of all the primitives of the side-scan sonar receiving array
  • the derivation process of the signal steering vector matrix a composed of all the primitives of the side-scan sonar receiving array is as follows:
  • N the number of primitives is N, the N primitives are uniformly distributed, and the distance between adjacent primitives is d.
  • ⁇ s is the parallel multi-beam steering angle
  • the reference primitives are evenly distributed along the receiving array according to the required number of beams; Among them, in the calculation of the received signal delay of each primitive, a unified reference is required, and this reference is the reference primitive.
  • Equation (3) When considering simple parallel multi-beams, that is, when the beam steering angle of each beam is 0 degrees, and without considering the noise and interference signal N(t), the output of each beam degenerates into the accumulation of several primitive data, then Equation (3) can be simplified as:
  • X(t) [x 1 (t),x 2 (t),x 3 (t)...x j (t)];
  • x j (t) is the j-th pre-beam vector in X (t);
  • s i (t) is the single-beam signal received by the i-th element;
  • the parallel beam imaging sonogram is drawn.
  • the fan-beam imaging mode is always used to process the single-beam signals received by all the primitives in the side-scan sonar receiving array to obtain the fan-beam imaging sonogram.
  • the primitive domain signals received by all primitives of the side-scan sonar receiving array are processed to obtain a fan beam domain signal model
  • X(t) 1 is the output vector matrix of the fan beam
  • a 1 is the sector signal steering vector matrix composed of all the elements of the side-scan sonar receiving array
  • S(t) 1 is the composition of all the elements of the side-scan sonar receiving array
  • N(t) 1 is the noise and interference sector signal matrix composed of all the elements of the side-scan sonar receiving array
  • the derivation process of the sector-shaped signal steering vector matrix a 1 composed of all the primitives of the side-scan sonar receiving array is as follows:
  • the N primitives are uniformly distributed, and the distance between adjacent primitives is d;
  • ⁇ s1 is the steering angle of the fan-shaped multi-beam
  • rs1 is the distance between the s1th primitive and the target to be measured distance, then the delay of the received signal between the nth primitive and the reference primitive is:
  • ⁇ N is the time delay of the received signal between the nth primitive and the reference primitive; f 0 is the working frequency; j is the imaginary unit.
  • the fan beam opening angle is [-10°, 10°]
  • the beam opening angle is 1°
  • the fan beam steering angle ⁇ s1 -10°, -9°, -8°, . . . 10°.
  • x M (t) is the fan beam vector of the Mth primitive
  • s i (t) 1 is the fan beam signal received by the i-th element
  • the method further includes: according to different speed of the ship, first obtain the result of observing the suspected target through the single-beam imaging acoustic image or the parallel beam imaging acoustic image, and then obtain the fine observation result of the target through the fan-shaped beam imaging acoustic image, according to the obtained It can determine the position of the target to be measured in the sea area and realize the detection of the target to be measured.
  • the length of the side scan sonar array is 0.6m
  • the number of primitives is 36
  • the working frequency is 600kHz
  • the detection range is 130m
  • the speed is less than 4 knots
  • the beam coverage opening angle is designed to be -4 degrees ⁇ 4 degrees. Because the speed is small, the single beam imaging mode and the fan-shaped multi-beam imaging mode are adopted according to the low speed mode of the ship.
  • the single beam adopts the beamforming technology based on near-field focusing, and the beam steering angle is 0 degrees;
  • the fan-shaped multi-beam adopts the near-field focusing beamforming technology, the beam steering angle is -4 degrees to 4 degrees, and the beam spacing is 0.2 degrees.
  • the side-scan sonar receiving array acquires a single-beam sonar beam domain echo signal, and acquires multiple frames of echo signals.
  • the beam data is displayed on the computer screen in the form of a waterfall chart, and a single beam imaging sound chart is formed, and three points D, E, and F are obtained from the chart as the suspected target for observation.
  • the beam data of the fan-shaped multi-beam acquired in each frame is displayed on the computer screen to form a fan-beam imaging acoustic image, and three points A, B, and C are obtained from the image as fine observations. Target.
  • a and D are the brightest spots, and they are located in the same position.
  • a multi-mode imaging mode of the target to be detected is obtained, which has both high-resolution characteristics brought by mechanical motion and flexibility of fan beams, which can provide help for subsequent detection and identification to reduce false alarm rate.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine consistant : à diviser un réseau de réception de sonar à balayage latéral en une pluralité de primitives, chaque primitive recevant un signal à faisceau unique ; pendant la navigation d'un navire, à aligner un sonar à balayage latéral sur une certaine zone de mer en vue d'un balayage afin de transmettre des signaux à faisceaux multiples de différents angles ; lorsque le navire est dans un mode de navigation à basse vitesse, à traiter les signaux à faisceau unique reçus par toutes les primitives dans le réseau de réception de sonar à balayage latéral à l'aide d'un mode d'imagerie à faisceau unique afin d'obtenir une carte sonore d'imagerie à faisceau unique ; lorsque le navire est dans un mode de navigation à grande vitesse, à traiter les signaux à faisceau unique reçus par toutes les primitives dans le réseau de réception de sonar à balayage latéral à l'aide d'un mode d'imagerie à faisceau parallèle pour obtenir une carte sonore d'imagerie à faisceau parallèle ; et pendant la navigation du navire, à traiter les signaux à faisceau unique reçus par toutes les primitives dans le réseau de réception de sonar à balayage latéral à l'aide d'un mode d'imagerie à faisceau en éventail tout le temps afin d'obtenir une carte sonore d'imagerie par faisceau en éventail.
PCT/CN2021/104223 2021-02-08 2021-07-02 Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine WO2022166097A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110180573.7A CN114910915A (zh) 2021-02-08 2021-02-08 一种侧扫声呐的水下目标多模式成像方法
CN202110180573.7 2021-02-08

Publications (1)

Publication Number Publication Date
WO2022166097A1 true WO2022166097A1 (fr) 2022-08-11

Family

ID=82740815

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/104223 WO2022166097A1 (fr) 2021-02-08 2021-07-02 Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine

Country Status (2)

Country Link
CN (1) CN114910915A (fr)
WO (1) WO2022166097A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115755068A (zh) * 2022-11-09 2023-03-07 广东智能无人系统研究院 一种海底管线状态在线智能诊断系统
CN115856898A (zh) * 2023-03-03 2023-03-28 山东科技大学 一种适应于全海深的面阵三维成像声呐点位归算方法
CN116482335A (zh) * 2023-04-26 2023-07-25 中国冶金地质总局第二地质勘查院 一种海砂矿勘查方法
CN116930976A (zh) * 2023-06-19 2023-10-24 自然资源部第一海洋研究所 基于小波模极大值的侧扫声呐图像的海底线检测方法
CN117408879A (zh) * 2023-10-26 2024-01-16 中国人民解放军32021部队 一种侧扫声呐图像拼接方法和装置
CN117522684A (zh) * 2023-12-29 2024-02-06 湖南大学无锡智能控制研究院 水下侧扫声呐图像拼接方法、装置及系统
CN117890894A (zh) * 2024-03-15 2024-04-16 浙江星天海洋科学技术股份有限公司 多波束探测系统及方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060023570A1 (en) * 2004-08-02 2006-02-02 Johnson Outdoors Inc. Sonar imaging system for mounting to watercraft
CN105629249A (zh) * 2016-03-28 2016-06-01 北京海卓同创科技有限公司 一种多波束侧扫声纳装置
CN111190168A (zh) * 2018-11-14 2020-05-22 中国科学院声学研究所 一种侧扫声纳的姿态稳定方法
JP2020173213A (ja) * 2019-04-12 2020-10-22 日本電気株式会社 ソーナー画像処理装置、ソーナー画像処理方法及びプログラム

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060023570A1 (en) * 2004-08-02 2006-02-02 Johnson Outdoors Inc. Sonar imaging system for mounting to watercraft
CN105629249A (zh) * 2016-03-28 2016-06-01 北京海卓同创科技有限公司 一种多波束侧扫声纳装置
CN111190168A (zh) * 2018-11-14 2020-05-22 中国科学院声学研究所 一种侧扫声纳的姿态稳定方法
JP2020173213A (ja) * 2019-04-12 2020-10-22 日本電気株式会社 ソーナー画像処理装置、ソーナー画像処理方法及びプログラム

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Doctoral Dissertation", 1 November 2003, WUHAN UNIVERSITY, CN, article FANLIN YANG: "Fusing and Classifying Multi-beam Sonar and Side-scan Sonar Data", pages: 1 - 137, XP055955726 *
LIAO XIAOMAN, XU XIANG: "Design and Implementation of Multibeam Sidescan Sonar", AUDIO ENGINEERING - DIANSHENG JISHU, BEIJING DIANSHI DIANSHENG ZAZHISHE, JP, vol. 36, no. 3, 17 March 2012 (2012-03-17), JP , pages 47 - 52,65, XP055955723, ISSN: 1002-8684, DOI: 10.16311/j.audioe.2012.03.003 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115755068A (zh) * 2022-11-09 2023-03-07 广东智能无人系统研究院 一种海底管线状态在线智能诊断系统
CN115856898A (zh) * 2023-03-03 2023-03-28 山东科技大学 一种适应于全海深的面阵三维成像声呐点位归算方法
CN116482335A (zh) * 2023-04-26 2023-07-25 中国冶金地质总局第二地质勘查院 一种海砂矿勘查方法
CN116482335B (zh) * 2023-04-26 2023-12-15 中国冶金地质总局第二地质勘查院 一种海砂矿勘查方法
CN116930976A (zh) * 2023-06-19 2023-10-24 自然资源部第一海洋研究所 基于小波模极大值的侧扫声呐图像的海底线检测方法
CN116930976B (zh) * 2023-06-19 2024-03-26 自然资源部第一海洋研究所 基于小波模极大值的侧扫声呐图像的海底线检测方法
CN117408879A (zh) * 2023-10-26 2024-01-16 中国人民解放军32021部队 一种侧扫声呐图像拼接方法和装置
CN117408879B (zh) * 2023-10-26 2024-05-10 中国人民解放军32021部队 一种侧扫声呐图像拼接方法和装置
CN117522684A (zh) * 2023-12-29 2024-02-06 湖南大学无锡智能控制研究院 水下侧扫声呐图像拼接方法、装置及系统
CN117522684B (zh) * 2023-12-29 2024-03-19 湖南大学无锡智能控制研究院 水下侧扫声呐图像拼接方法、装置及系统
CN117890894A (zh) * 2024-03-15 2024-04-16 浙江星天海洋科学技术股份有限公司 多波束探测系统及方法
CN117890894B (zh) * 2024-03-15 2024-05-28 浙江星天海洋科学技术股份有限公司 多波束探测系统及方法

Also Published As

Publication number Publication date
CN114910915A (zh) 2022-08-16

Similar Documents

Publication Publication Date Title
WO2022166097A1 (fr) Procédé d'imagerie multimode fondé sur un sonar à balayage latéral de cible sous-marine
CN112505710B (zh) 一种多波束合成孔径声呐三维成像算法
KR19990078351A (ko) 수중물체탐지장치
CN110658514B (zh) 一种水下静态目标的分类识别方法
CN110412588B (zh) 一种基于交叉阵列的目标三维信息测量方法及系统
Sabra et al. Experimental demonstration of iterative time-reversed reverberation focusing in a rough waveguide. Application to target detection
CN108957462A (zh) 一种基于平坦海底的多波束水体数据处理方法
CN111880185A (zh) 一种水下目标勘测处理方法及系统
Châtillon et al. SAMI: A low-frequency prototype for mapping and imaging of the seabed by means of synthetic aperture
AU2018389732A1 (en) Marine surface drone and method for characterising an underwater environment implemented by such a drone
CN110907937B (zh) 一种基于“t”型阵的掩埋物合成孔径三维成像方法
CN113108778B (zh) 一种具备多条带模式的深水多波束测深方法及系统
CN111190168B (zh) 一种侧扫声纳的姿态稳定方法
JP5082031B2 (ja) 魚群の魚量情報を算出可能な水中探知装置及びその方法
CN111142112A (zh) 一种水下锚系小目标快速非成像检测方法
US11668821B2 (en) Position correction using towed sensor
JPH0679065B2 (ja) 海底探索装置
Qin et al. The 3D imaging for underwater objects using SAS processing based on sparse planar array
Trevorrow Salmon and herring school detection in shallow waters using sidescan sonars
CN113687364B (zh) 一种三维成像声纳图像假底的抑制方法
CN114460587B (zh) 一种主动声呐全景接触目标快速辨识方法
Ehrhardt et al. Comparison of different short-range sonar systems on real structures and objects
Andrews et al. Swathmap: Long range sidescan sonar mapping of the deep seafloor
JP2859916B2 (ja) エコー信号処理装置及び該装置を含む水中探知装置
Schock Synthetic aperture 3D buried object imaging

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21924104

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21924104

Country of ref document: EP

Kind code of ref document: A1