Multitask and multispectral sonar

Abstract

A measurement system including a multibeam echo sounder having a single array of projectors and a single array of hydrophones constructs a multi-signal message and deconstructs a corresponding multi-signal echo to perform multiple measurement tasks substantially simultaneously.

Description

[0001] This application is a divisional application of PCT application (PCT / US2017 / 025667) which entered the Chinese national phase on October 29, 2018 (application number 201780026658.1, invention title "Multi-task and Multi-spectral Sonar").

[0002] Priority claims and by reference

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 329,631, filed April 29, 2016. For various purposes, the entire disclosures of the following U.S. patents are incorporated herein by reference: 3,144,631 relating to Mills crossover sonar; 8,305,841 relating to sonar for mapping seabed topography; 7,092,440 relating to spread spectrum communication techniques; 5,483,499 relating to Doppler frequency estimation; and 9,244,168 relating to frequency pulse sonar. Technical Field

[0004] This invention relates to underwater acoustic systems, methods of using underwater acoustic systems, and methods of processing and using data generated by underwater acoustic systems. Specifically, this invention relates to measurement systems including sonar systems with methods of use that enable the simultaneous performance of multiple measurement tasks using a single transmitting transducer array and a single receiving transducer array. Background Technology

[0005] A month after the Titanic struck an iceberg in 1912, British meteorologist Lewis Richardson applied for a patent for an underwater ranging device with the British Patent Office. Richardson's modern successor is commonly referred to as sonar (sound navigation and ranging) devices. These devices involve using an array of transducers to project sound or pressure waves through a liquid medium and receiving the corresponding echoes from the characteristics of the scattered and / or reflected impact waves.

[0006] Information about these features and their environment can be obtained from echoes. For example, depth measurements provide information about the depth of the scattering center, water column measurements provide information about the scattering center within the water column, and seabed characterization measurements provide information about the scattering center at and below the seabed surface.

[0007] The diversity and quality of the information returned in the echo can be determined in part by the characteristics of the signal used to excite the projector transducer. The cost of acquiring this information is heavily influenced by the timeframe, within which manpower and equipment are required to obtain the information.

[0008] While some progress has been made in improving data quality and diversity while simultaneously reducing the time required for underwater measurements, particularly through the use of multibeam echo sounders, long-standing technical challenges and the risks associated with building and testing expensive new measurement equipment pose significant obstacles to further similar improvements. Summary of the Invention

[0009] The present invention provides a measurement system including a multibeam echo sounder and / or a portion thereof. In one embodiment, the present invention provides a measurement system for performing multiple tasks in each message cycle, the measurement system comprising a multibeam echo sounder system mounted on a watercraft, the measurement system comprising: an acoustic transceiver for use with one or more transducers in a single projector array and multiple transducers in a single hydrophone array; a projector array disposed relative to the hydrophone array to form a Mills cross; the transceiver for use in multiple non-overlapping frequency bands having corresponding bandwidths and a number of N such bands; the transceiver for synthesizing a transmitter message containing one or more signals from each frequency band, the signals supporting multiple tasks; and the message for stimulating the projector array such that a stripe at the bottom of the water body is acoustically penetrated by each signal in the message, and a message echo from the scattering center of the acoustic penetration is returned to the hydrophone array; wherein a first frequency band in the frequency bands is used to support a first task, a second frequency band in the frequency bands is used to support a second task, the first task frequency band and the second task frequency band are widely spaced to facilitate measurement system identification of one or more frequency-dependent characteristics of the scattering center of the acoustic penetration. It is worth noting that measurement data can be collected from the acoustic penetration of features in water bodies, including any ocean, bay, fjord, estuary, lake, river, navigable waterway, canal, and port. Attached Figure Description

[0010] The invention is described with reference to the accompanying drawings. These drawings, which are included herein and form part of the specification, illustrate embodiments of the invention and, together with the description, further serve to explain its principles, enabling those skilled in the art to construct and use the invention.

[0011] Figure 1A A measurement system including the multibeam echo sounder system of the present invention is shown;

[0012] Figures 1B to 1E It shows Figure 1A At least a portion of the embodiments of the multibeam echo sounder system;

[0013] Figure 2A It shows the supply Figure 1A The message cycle used by the multibeam echo sounder system;

[0014] Figures 2B to 2E The message includes multiple signals with different frequencies, for use as a source. Figure 1A The system uses a multibeam echo sounder system;

[0015] Figures 3A to 3D It shows the result of Figure 1A The multi-frequency message sound penetration strip of the multibeam echo sounder;

[0016] Figure 4 It shows that it will use Figure 1A Table of measurement tasks performed by the multibeam echo sounder;

[0017] Figure 5 It shows that it will use Figure 1A The table shows the multi-task measurements performed by the multibeam echo sounder;

[0018] Figures 6A to 6G Showing will use Figure 1A The multibeam echo sounder performs multi-task measurements. Detailed Implementation

[0019] Examples of embodiments of the invention are described in the disclosure provided on the following pages. The designs, drawings, and descriptions are non-limiting examples of the disclosed embodiments. For example, other embodiments of the disclosed apparatus and / or methods may include or exclude the features described herein. Furthermore, the described features, advantages, or benefits may apply only to certain embodiments of the invention and should not be used to limit the disclosed invention.

[0020] The term "coupling" as used herein includes both direct and indirect connections. Furthermore, in the case of coupling between the first and second devices, an intervention device, including an active device, may be located therebetween.

[0021] Figures 1A to 1E A measurement system including a multibeam echo sounder system is shown, and an embodiment of the multibeam echo sounder is described.

[0022] Figure 1A A measurement system according to embodiment 100A of the present invention is illustrated. The measurement system includes an echo sounder system, such as a multibeam echo sounder system 102, which can be mounted on a surface vehicle or vessel, a remotely operated vehicle, an autonomous underwater vehicle, etc. As further described below, the echo sounder and / or measurement system output 114 can be performed simultaneously with the echo sounder processing of hydrophone data, as in some embodiments for water depth measurement, or separately from the processing of hydrophone data, as in some embodiments for bottom classification of water bodies.

[0023] The data acquired by the multibeam echo sounder system 104 includes data from an echo sounder listening device, such as a hydrophone (e.g., a transducer), which receives echoes related to sound / pressure waves emitted from the echo sounder projector but returned due to interactions with various inhomogeneities. These interactions can take the form of reflection or scattering. Inhomogeneities (also known as reflectors and scattering centers) represent discontinuities in the physical properties of the medium. Scattering centers can be found in one or more of the following: i) the acoustic transmission volume of a body of water (e.g., a column of water), ii) the acoustic transmission surface at the bottom, or iii) within the acoustic transmission volume of a shallow bottom.

[0024] Biological scattering centers may be present in the water column because these centers are part of marine life. Non-biological scattering centers may exist in the water column as bubbles, dust and sand grains, thermal microstructures, and turbulence of natural or anthropogenic origin (e.g., ship wakes). Scattering centers on the bottom surface may be due to the mechanical roughness of the bottom, such as ripples, or due to the inherent size, shape, and physical arrangement of the bottom composition, such as mud, sand, shell fragments, pebbles, and large rocks, or both. Scattering centers in the seabed may be due to biological disturbance of sediments, stratification of different sedimentary materials within the seabed, or buried man-made structures, such as flow lines.

[0025] Data processing within the echo sounder system may include simultaneous processing of hydrophone data 106, for example, to obtain depth sounding and / or backscatter data. Data processing may also include non-simultaneous processing of multibeam echo sounder system data 108, for example, to characterize bottom conditions or water column.

[0026] Data processing may include utilizing supplemental or other data. For example, simultaneous processing of hydrophone data 106 may utilize simultaneous 110 and / or non-simultaneous 112 data, such as simultaneously collected geolocation system (“GPS”) data, sound velocity measurements, attitude and navigation information. For example, non-simultaneous processing of echo sounder system data may utilize simultaneous 110 and / or non-simultaneous 112 data, such as non-simultaneously collected bottom composition data and tidal records.

[0027] Figure 1BA portion of a first multibeam echo sounder system (“MBES”) 100B is shown. The echo sounder system includes a transducer section 120 and an acoustic transceiver 122. The echo sounder system may include transceiver interfaces, such as an interface module 124 and / or a workstation computer 126, for one or more of data processing, data storage, and human-machine interface. Here, the transducer with the Mills cross configuration 120 includes a transmitter or projector array 130 and a receiver or hydrophone array 140. The projectors in the projector array may be spaced along a line parallel to the keel line or track of the vehicle on which they are mounted, which may be referred to as a track-mounted configuration. In some embodiments, the receiver of the transceiver 122 has an operating frequency range that matches the operating frequency range of the projectors and / or hydrophones.

[0028] During echo sounder operation, sound or pressure waves emitted from the projector array travel through the water body and possibly to the bottom below the water surface. In doing so, they may undergo interactions that interfere with the propagation trajectory of the pressure waves, such as reflection or scattering. The hydrophone array can "hear" some of these reflections or echoes. See, for example, the disclosure of U.S. Patent 3,144,631 to Etal, the entire contents of which are incorporated herein by reference.

[0029] Acoustic transceiver 122 includes a transmitter section 150 and a receiver section 170. The acoustic transceiver can be configured to transmit to a single projector array 130 and receive from a single hydrophone array 140. In some embodiments, such a transceiver may be said to work with a single transmitter array and a single receiver array. Unless otherwise stated, the term transceiver does not require conventional transmitter and receiver packaging.

[0030] The echo sounder may also include an interface module, such as interface module 124, for interconnection with transceiver 122. This interface module can provide power to the transceiver, communication with the transceiver, communication with workstation computer 126, and communication with other data sources, such as a concurrent GPS data source.

[0031] The workstation computer 126 can provide one or more data processing functions, such as data processing for visualization of survey results, data storage, such as storing depth sounding data and backscatter data, user input, and display of any input, system status, and survey results.

[0032] Figure 1C A portion of a second multibeam echo sounder system (“MBES”) 100C is shown. The echo sounder system includes a transducer section 120, a transmitter section 150, and a receiver section 170. Some embodiments include an interface section 190 and / or a management section 192.

[0033] The transducer section includes transducers for generating acoustic messages and transducers for receiving acoustic messages. For example, the transducer section may include a projector array 130 and a hydrophone array 140.

[0034] Projectors in a projector array may include piezoelectric elements, such as ceramic elements that may or may not be stacked. Element geometries may include circular and non-circular geometries, such as rectangular geometries. Some projectors operate in frequency ranges of approximately 10 kHz to 100 kHz, approximately 50 kHz to 550 kHz, or approximately 100 kHz to 1000 kHz.

[0035] Hydrophones in a hydrophone array may include piezoelectric elements, such as ceramic elements. Element geometries may include circular and non-circular geometries, such as rectangular geometries. Some hydrophones operate in frequency ranges of approximately 10 kHz to 100 kHz, approximately 50 kHz to 550 kHz, or approximately 100 kHz to 1000 kHz.

[0036] During operation of the projector array 130 and the hydrophone array 140, the transmitter portion excites the projector array to emit an output message 137, which travels through the liquid medium to a reflector or scattering center 138, where it is reflected or scattered. Subsequently, a return or input message 139 travels to the hydrophone array 140 for processing by the receiver 170. Notably, the acoustic / pressure wave input 136 received at the hydrophone array 140 may include a perturbed version of the transmitted message 137, as well as parasitic signals and / or noise content.

[0037] The transmission section 150 may include a signal generator block 158, a transmission beamformer block 156, a summing block 154, and a power amplifier block 152. The transmission section generates signals that will be used to construct the message 137. It is worth noting that the message may or may not consist of multiple signals. If the message consists of multiple signals, it may contain i) parallel (superimposed) signals, ii) serial (cascaded) signals, or iii) a combination of parallel and serial signals. In one embodiment, multiple signals are generated and transmitted at multiple different center frequencies Scf1, Scf2...

[0038] Transmit beamformer block 156 receives signals from signal generator block 158, which performs beamforming for each signal. The beams are combined in summing block 154 to construct parallel, serial, or combined messages M. In power amplifier block 152, the time-series voltage of the messages is amplified to excite or drive transducers in projector array 130. In one embodiment, each transducer is driven by a corresponding amplifier.

[0039] The receiving section 170 includes multiple hydrophone signal processing pipelines. In one embodiment, the receiving section includes a hardware pipeline block / analog signal processing block 172, a software pipeline block / digital signal processing block 174, a receive beamformer block 176, and a processor block 178. The receiving section provides isolation and processing of messages 137 from inputs 136 received from the hydrophone array 140. For example, some embodiments process echoes to additionally determine depth based on round-trip time, which is based on matching the transmitted messages 137 with corresponding received messages isolated from the hydrophone array inputs 136.

[0040] In hardware pipeline block 172, multiple hydrophone array transducers of hydrophone array 140 provide inputs to multiple hardware pipelines that perform signal conditioning and analog-to-digital conversion. In some embodiments, the analog-to-digital conversion is configured for oversampling, wherein the converter Fin (highest input frequency) is less than Fs / 2 (half the converter sampling frequency). In one embodiment, transceiver 122, operating at a maximum frequency of approximately 800 kHz, utilizes an analog-to-digital converter with a sampling rate of 5 MHz.

[0041] In software pipeline block 174, hardware pipeline 172 provides input to the software pipeline. One or more pipelines serve each hydrophone in the hydrophone array. Each pipeline provides down-conversion and filtering. In various embodiments, the filter recovers the message from the hydrophone input 136. In one embodiment, each hydrophone is served by multiple pipelines for decomposing the multi-frequency message into multiple signals with corresponding center frequencies S'cf1, S'cf2...

[0042] In the receive beamforming or manipulation block 176, software pipeline 174 provides beamformer inputs. Beamformer functions include phase shifting and / or time delay summation of multiple input signals. In one embodiment, a beamformer is provided for each frequency S'cf1, S'cf2... For example, in the case where the software pipeline operates at two frequencies, the input to the first beamformer is the software pipeline operating at the first frequency, and the input to the second beamformer is the software pipeline operating at the second frequency.

[0043] In processor block 178, the beamformer of beamformer block 176 provides processor input. Processor functions include bottom detection, backscatter processing, data reduction, Doppler processing, acoustic imaging, and generation of short time series (sometimes referred to as "snippets") of backscatter.

[0044] In one embodiment, a management section 192 and a sensor interface section 190 are provided. The management section includes an interface module 194 and / or a workstation computer 196. The sensor interface section provides interface signals from one or more sensors ES1, ES2, ES3, such as sensors for time (e.g., GPS), motion, attitude, and sound speed.

[0045] In various embodiments, control and / or control-related signals are exchanged between the management section 192 and one or more of the following: power amplifier block 152, software pipeline block 174, transmit beamformer block 156, receive beamformer block 176, signal generator block 158, and processor block 178. Furthermore, in various embodiments, sensor interface data 190 is exchanged with the management section 192 and processor block 178.

[0046] Figure 1D A portion of a second multibeam echo sounder system (“MBES”) 100D is shown. The echo sounder system includes a transducer section 120, a transmitter section 150, and a receiver section 170. Some embodiments include an interface section 190 and / or a management section 192.

[0047] In the illustrated embodiment, message 153, containing a number of N signals with N correspondingly different center frequencies, is used to excite multiple projectors in the projector array, and a receiver with a number of T hardware or software pipelines and (T×N) hardware or software pipelines can be used to process the T hydrophone signals to recover the unique echo information of each of the N frequencies.

[0048] The transmitter section 150 is used to excite the projector array 130. This section includes a signal generator block 158, a transmission beamformer block 156, a summing block 154, and a power amplifier block 152.

[0049] Signal generator block 158 generates N signals S1, S2...SN. The signals have center frequencies cf1, cf2...cfn that can be spaced apart at intervals of, for example, 50 to 150 kHz. In one embodiment, the signals are spaced apart at intervals of at least 100 kHz.

[0050] Transmit beamformer block 156 receives the outputs of N signal generator blocks. For each of the N generated signals, the beamformer block generates a set of output beam signals, resulting in N sets of output beam signals.

[0051] Summing block 154 receives and sums the signals in N sets of output beams to provide summation output 153.

[0052] The power amplifier block 152 includes S amplifiers for driving the individual projectors in the projector array 130. Each power amplifier receives a summation output 153, amplifies the signal, and uses the amplified signal to drive the corresponding projector.

[0053] An array of T hydrophones 140 is used to receive echoes of sound / pressure waves originating from a projector array 130. The resulting hydrophone signals are processed in a receiver section 170, which includes a hardware pipeline block 172, a software pipeline block 174, a receive beamformer block 176, and a processor block 178.

[0054] In hardware pipeline block 172, T pipelines provide independent signal conditioning and analog-to-digital conversion for each of the T hydrophone signals.

[0055] In software pipeline block 174, (T×N) software pipelines provide downconversion and filtering at N frequencies for each of the T hardware pipeline outputs. As shown in the figure, each of the T hardware pipeline outputs 181, 182, and 183 provides N software pipeline inputs a, b and c, d and e, f (i.e., 3×2 = 6, where T = 3 and N = 2).

[0056] In the receiving beamformer block 176, the outputs of (T×N) software pipeline blocks 174 are used to form N sets of beams. A beamformer is provided for each of the N frequencies. For example, in the case where there are T=3 hydrophones and the software pipeline operates at N=2 frequencies, the input to the first beamformer is a software pipeline operating at the first frequencies a1, c1, e1, and the input to the second beamformer is a software pipeline operating at the second frequencies b1, d1, f1.

[0057] In processor block 178, N processors receive various beam groups formed by beamformer block 176. Processor block 178 exchanges data with management section 192 and provides sensor interface 190 data ES1, ES2, ES3 to management section and / or processor block.

[0058] In various embodiments, control signals from management block 192 are used to configure power amplifier block 152 (e.g., an “S” power amplifier for shadowing), control transmit beamformer 156 and receive beamformer 176, select the operating frequency of software pipeline block 174, and set the operating frequency of signal generator block 158.

[0059] As described above, the disclosed echo sounder transmitter can construct a message containing signals with N frequencies. Furthermore, the echo sounder can utilize a receiver with T hardware pipelines and (T×N) software pipelines to process T hydrophone signals to recover the unique echo information of each of the N frequencies.

[0060] Figure 1E A portion of a third multibeam echo sounder system (“MBES”) 100E is shown. The echo sounder system includes a transducer section 120, a transmitter section 150, and a receiver section 170. Some embodiments include an interface section 190 and / or a management section 192.

[0061] In the illustrated embodiment, message 153, comprising first and second signals Scd1 and Scd2 having first and second different center frequencies N=2, is used to excite three projectors in the projector array, and a receiver having three hardware pipelines and six software pipelines is used to process three hydrophone signals T=3 to recover the unique echo information of each of the N frequencies.

[0062] The transmitter section 150 is used to excite the projector array 130. This section includes a signal generator block 158, a transmission beamformer block, a summing block 154, and a power amplifier block 152.

[0063] In signal generator block 158, N=2 signal generators are shown operating at different user-selectable center frequencies f1, f2. In each beamformer of beamformer block 156, multiple beams are generated from each signal. In summing block 154, the beams are combined to produce summing block output signal 153.

[0064] Transducer block 120 includes a projector array 130 and a hydrophone array 140, the hydrophone array being configured as a Mills cross. As shown, the projector array has three projectors 131, and the hydrophone array has three hydrophones 141. In power amplifier block 152, a summation signal or message 153 is an input to the power amplifier driving each projector.

[0065] The applicant notes that, for ease of illustration, the count of projectors and hydrophones is limited to three. As those skilled in the art will understand, a Mills cross array does not need to have an equal number of projectors and hydrophones, nor is it necessary to limit the number of these transducers to three. For example, modern multibeam echo sounders may use 1 to 96 or more projectors and 64 to 256 or more hydrophones.

[0066] T = 3 hydrophone arrays 141 are used to receive echoes generated by sound / pressure waves originating from projector array 130. The resulting hydrophone signals are processed in receiver section 170, which includes hardware pipeline block 172, software pipeline block 174, receive beamformer block 176, and processor block 178.

[0067] In hardware pipeline block 172, each of the T=3 hardware pipelines processes the corresponding hydrophone 141 signal through an analog component including an analog-to-digital converter. In the illustrated embodiment, the hardware pipeline provides sequential signal processing via a first amplifier, an anti-aliasing filter such as a low-pass anti-aliasing filter, a second amplifier, and an analog-to-digital converter.

[0068] In software pipeline block 174, each of the T=3 hardware pipeline outputs is processed via N=2 software pipelines through down-conversion and matched filtering. In the illustrated embodiment, the software pipeline provides sequential signal processing via a mixer (oscillator not shown for clarity), a bandpass filter, a decimator, and a matched filter. Communication can occur via a communication link between any of the processor block 178, signal generator block 158, hardware pipeline block 172, software pipeline block 174, and beamformer block 176. See, for example... Figure 1C -D.

[0069] In the receive beamformer block 176, each of the N=2 beamformers processes the signal. Thus, the three software pipeline outputs at the first center frequency are processed by the first beamformer, and the three software pipeline outputs at the second center frequency are processed by the second beamformer. It is worth noting that the beamformers can be implemented in hardware or software. For example, multiple beamformers can be implemented in one or more field-programmable gate arrays (“FPGAs”).

[0070] In processor block 178, each of N=2 processors is used to process the corresponding beamformer output. Here, a first plurality of beams generated by a first beamformer are processed in the first processor, and a second plurality of beams generated by a second beamformer are processed in the second beamformer. The processor outputs are interconnected with management section 192. It is worth noting that one or more processors can be implemented in a single device, such as a single digital signal processor (“DSP”), or in multiple devices, such as multiple digital signal processors.

[0071] Supplemental data can be provided via sensor interface section 190, which engages with multiple sensors ES1, ES2, and ES3. The sensor interface module can provide sensor data to the processor in management section 192 and / or processor block 178.

[0072] The management block 192 includes a sonar interface 194 and / or a workstation computer 196. In various embodiments, control signals from the management block 192 are used to configure the power amplifier block 152 (e.g., for array shadowing), control the transmit beamformer 156 and the receive beamformer 176, select the operating frequency of the software pipeline block 174, set the operating frequency of the signal generator block 158, and provide one or more of the following operating instructions to the processor block 178:

[0073] The applicant noted that Figures 1C to 1E The echo sounder system can be used to process hydrophone echoes from targets i) present in the acoustic penetration volume of the water body, ii) located on the acoustic penetration surface at the bottom, or iii) located in the acoustic penetration volume at the bottom.

[0074] Figures 2A to 2E The ping period is shown, and the multi-frequency messages transmitted within the ping period are described.

[0075] Figure 2A The message cycle 200A is illustrated. This cycle includes a series of operations involving message transmission during time t1 and message reception during time t3. Message transmission refers to the process of exciting the projector array 130, and message reception refers to the supplementary process of interpreting the message echo received by the hydrophone array 140. A latency t2, which varies primarily with range, angle, and sound speed, can lie between the end of message transmission and the beginning of message reception. This latency can be determined by the round-trip time of the longest detection distance, for example, from the echo of the farthest cell within the strip through which the projector array's sound penetrates. In some embodiments, the message transmission length is in the range of 10 to 60 microseconds. In some embodiments, the transmitted message length is approximately 10 milliseconds.

[0076] Figure 2B A first multi-frequency message 200B is shown. In the illustrated embodiment, the message includes three signals, which may include single or multiple waveforms. The first signal occupies at least a portion of a lower frequency band, for example, a band extending from 100 kHz to 200 kHz. The second signal occupies at least a portion of an intermediate frequency band, for example, a band extending from 300 kHz to 400 kHz. The third signal occupies at least a portion of a higher frequency band, for example, a band extending from 500 kHz to 600 kHz. This message may be referred to as a multi-frequency message, having signals in a wide-spaced frequency band. The frequency band used by the signals may be referred to as the signal band, wherein there is a gap band between the first signal band and the nearest adjacent second signal band.

[0077] Wide-spaced frequency bands contrast with narrow-spaced and minimal-spaced frequency bands. In practice, these bands can be spaced just enough to separate the signal and / or prevent interference. When signal separation relies on a bandpass filter, the performance of the bandpass filter determines the minimum band spacing. For sonar systems operating in the 100 to 400 kHz range, the band spacing can be approximately 1 to 3 kHz, approximately 3 to 5 kHz, or approximately 5 to 10 kHz.

[0078] When the same target is acoustically penetrated by a signal (e.g., a CW signal) in a narrow frequency band, the backscattering characteristics of the signal from the first frequency band are very similar to those of the signal from the second frequency band. Here, the difference in backscattering characteristics (e.g., backscattering intensity) may be small and / or beyond the detection range.

[0079] Minimizing the differences in backscattering characteristics is ideal when the surveyor's goal is to increase the detection density along the track. This is also ideal when the surveyor's goal is to simplify the measurement data standardization process by utilizing similar signal ranges and similar backscattering intensities. However, signals in wide-interval frequency bands do not meet these objectives.

[0080] Unlike signals in narrow-spaced frequency bands, signals in wide-spaced frequency bands can be selected to elucidate frequency-related differences presented by backscatterers or echo sources (e.g., the bottom of a body of water).

[0081] Furthermore, in cases where the backscattering response is frequency-dependent, projector emission over a wide frequency band can induce a distinguishable backscattering response. This may also be the case when the echo returns from the same scattering region.

[0082] In one embodiment, two frequency bands including corresponding signals may have a wide spacing when they do not have a narrow spacing. In another embodiment, two frequency bands including corresponding signals have a wide spacing when they do not have a narrow spacing.

[0083] In one embodiment, the two frequency bands comprising the corresponding signals are wide-spaced when their center frequencies are separated by at least twice the bandwidth of the narrowest signal. Furthermore, in one embodiment, the two frequency bands comprising the corresponding signals are wide-spaced when their center frequencies are separated by at least 30% of the lower of the two center frequencies. In one embodiment, the two frequency bands comprising the corresponding signals are wide-spaced when both conditions are met.

[0084] In one embodiment, when there is a statistically significant difference between the message echo portion attributable to the first signal and the message echo portion attributable to the second signal, the two frequency bands including the corresponding signals have a wide spacing. Echo features that can be evaluated to statistically significant differences include average backscatter intensity, angular response of backscatter intensity, and maximum detection range.

[0085] In one embodiment, two frequency bands including the respective signals have a wide spacing when the intensities of substantially simultaneous backscattered signals from the signal differ by a predetermined amount. It is noteworthy that backscattering intensity generally increases with frequency, while increasing the incident angle decreases backscattering intensity. In some embodiments, angularly averaged backscattering intensities can be compared to indicate whether the frequencies have a wide spacing. In some embodiments, the backscattering intensity at a specific incident angle θ (e.g., the projector's incident angle) is the basis for the above comparison, and a difference of approximately 2 dB or greater may indicate a wide frequency spacing. Examples are given below.

[0086] Consider a message comprising signals Sx and Sy in frequency bands Bx and By, where Bx is the lower of the two bands. The frequency bands have a wide spacing where the backscattered signal intensities BSx and BSy with a common incident angle θ cause BSy to exceed BSx by 2 dB or more. In one embodiment, the message length is less than approximately 10 milliseconds.

[0087] Any one or more of the above methods can be used to determine whether a frequency band has a wide spacing.

[0088] As described below, the number of signals and the spacing of the corresponding frequency bands within a message can be varied to adapt to specific applications and environmental conditions.

[0089] Figure 2C A second multi-frequency message 200C is shown. In the illustrated embodiment, the message comprises three signals that may be temporally adjacent, temporally substantially adjacent (e.g., a gap less than one signal length or approximately ten percent of the shortest signal length), or temporally spaced (e.g., a gap of one signal length or approximately ten percent or more of the shortest signal length). A first signal 232, in a lower frequency band and beginning at time ts1i, is temporally followed by a second signal 234 in an intermediate frequency band. The second signal is temporally followed by a third signal 236 in a higher frequency band ending at time ts3ii. This figure illustrates a multi-frequency message with serialized or serialized signals.

[0090] and Figure 2C different, Figure 2DA multi-frequency message transmitted over multiple acoustic pulses 200d is illustrated. In the illustrated embodiment, the message comprises three signals, which are not transmitted in a single acoustic pulse message, but rather in a multi-pulse message using three consecutive message cycles. These message cycles may be temporally adjacent, temporally substantially adjacent (e.g., a gap less than one signal length or approximately ten percent of the shortest signal length), or temporally spaced (e.g., a gap of one signal length or approximately ten percent or more of the shortest signal length, as shown). A first signal (signal 1) in the lower frequency band and between times tu1 and tu2 corresponds to the first acoustic pulse. A second signal (signal 2) in the middle frequency band and between times tu3 and tu4 corresponds to the second acoustic pulse. A third signal (signal 3) in the higher frequency band and between times tu5 and tu6 corresponds to the third acoustic pulse.

[0091] Figure 2E A third multi-frequency message 200E is shown. In the illustrated embodiment, this message includes three signals that overlap temporally with the earliest signal starting at ta and the latest signal ending at Tb. Here, the first signal 242 in the lower frequency band, the second signal 244 in the middle frequency band, and the third signal 246 in the higher frequency band illustrate a multi-frequency message with parallel signals.

[0092] Figure 3A The acoustic penetration of the water bottom via a multi-frequency message with a serialized signal of 300A is illustrated. Along the track of the multibeam echo sounder vehicle, three strips are acoustically penetrated via a serial message containing three signals. Here, the low-frequency strip is acoustically penetrated by the first signal in the low-frequency band, the mid-frequency strip by the second signal in the mid-frequency band, and the third high-frequency strip by the third signal in the high-frequency band. The strips move along the track due to the sequentially emitted signals and the movement of the sonar along the measurement track over time. Notably, due to the (1 / frequency²) relationship between signal frequency and range, the low-frequency strip has the maximum width w1, while the high-frequency strip has the minimum width w3 (w1>w2 and w2>w3). Furthermore, the strips associated with higher frequency bands may be narrower than the lower-frequency strips along the track direction.

[0093] Figure 3BThis illustrates acoustic penetration of the water bottom through a multi-frequency message containing 300B of parallel signals. Along the track of the multibeam echo sounder platform, three strips penetrate the water using information containing three parallel signals. Here, the low-frequency strip penetrates through the first signal in the lower frequency band, the mid-frequency strip through the second signal in the mid-frequency band, and the third high-frequency strip through the third signal in the higher frequency band. Because the message contains parallel signals, the strips do not move along the track. Instead, the strips overlap spatially because the parallel signals overlap temporally (overlap).

[0094] Figure 3C The image shows echoes from a portion of the water's bottom shared by multiple stripes, which are acoustically penetrated by multi-frequency messages with parallel signals of 300C. Here, Figure 3B Parallel signals along corresponding strip widths w1, w2, w3 allow the lower, middle, and higher frequency stripe sound to penetrate. Because parallel signal messages avoid strip displacement due to vehicle movement, a common stripe region shared by all stripes provides a common echo generation for each signal. This common region is within region 322 of the higher frequency stripe.

[0095] Figure 3D This diagram illustrates stripes located at the same position that undergo acoustic penetration via multi-frequency messages with parallel signals of 300d. Here, each of the lower, middle, and higher frequency band strips shares a common width w. Various configurations can produce stripes with this common location.

[0096] In the first example, the strips can be co-located to a strip or sector width less than or equal to the higher frequency band strip width by selecting echo sounder receive beamforming 176. In the second example, the strips can be located in the same position when there is a significant grating lobe limitation at higher frequencies restricting the available steering angle. In the third example, when operating in shallow water, the strips can be located in the same position so that higher attenuation at higher frequencies does not limit the detection range. The beamwidth associated with each frequency band typically varies with frequency, with higher frequencies providing higher angular resolution. However, frequency dependence can be mitigated by normalizing to a common beamwidth by changing the aperture of the transmit and receive arrays by disabling selected array elements.

[0097] Figure 4 The table illustrates the signal types and / or waveforms used for various missions and / or applications of the multibeam echo sounder 400. As shown in the table, signal types include CW (continuous wave), FM (frequency modulation), OSS (quadrature spread spectrum), PC (phase encoded), PT (pulse sequence), and LPI (low probability of intercept). Notably, frequency modulation includes linear FM or LFM.

[0098] Depth sounding and forward-looking missions can use any of CW, FM, OSS, PC, PT, and LPI. Imaging missions can use any of CW, FM, OSS, and PC, while sub-bottom profiling missions can use any of CW, FM, PC, and PT. More selective missions include water column missions that can use CW, FM, OSS, or PC; bottom classification missions that can use CW or FM; and Doppler missions that can use CW or PC.

[0099] It is worth noting that, as described above, the measurement operation is not limited to a single task or application as the measuring vehicle moves along the track. Instead, various embodiments of the multibeam echo sounder of the present invention, utilizing a single projector array and a single hydrophone array, can be used to simultaneously acquire and process data from multiple tasks. As the measuring vehicle moves along the track, the number of substantially simultaneous tasks that can be performed can be equal to or greater than the number of non-overlapping signal bands accommodated by the multibeam echo sounder system 102.

[0100] The multi-task measurements described below can utilize a multibeam echo sounder system 102, 100B-E with a single projector array and a single hydrophone array to acquire multi-task measurement data (e.g., single-trip measurement data) substantially simultaneously as the measurement vehicle travels along the track. In some embodiments, the motion of the measurement vehicle and / or serial transmission of message signals are considered substantially simultaneously.

[0101] Figure 5 A table showing the multitasking message content and message structure of an exemplary multitasking measurement 500 is provided. The table illustrates how multitasking messages can be constructed in a specific manner for multitasking measurement.

[0102] The first multi-task measurement includes a first bathymetry task and a second bathymetry task. The intermediate frequency band is typically not used.

[0103] The first sounding task uses a lower frequency band with CW or FM signals. The second sounding task uses a higher frequency band with CW or FM signals. These signals can be transmitted serially or in parallel within a single acoustic pulse message. These signals can also be transmitted as multi-pulse messages within individual acoustic pulses. Upon reading the applicant's disclosure, those skilled in the art will recognize the advantages of this multi-task measurement, which in particular addresses the long-standing problem associated with selecting one or the other of high-frequency (higher resolution / shorter distance) or low-frequency (lower resolution / long distance) measurements. In one embodiment, the frequency bands have wide spacing with band gaps between them.

[0104] The second multi-task measurement includes a first task to characterize the bottom or seabed of a water body and a second task to characterize the bottom or seabed of a water body. Typically, the mid-band frequency can be used.

[0105] The first bottom task uses a lower frequency band with CW signals. The second bottom task uses a higher frequency band with CW signals. These signals can be transmitted in parallel within a single acoustic pulse message. These signals can also be transmitted within corresponding acoustic pulses in a multi-pulse message. Those skilled in the art, upon reading the applicant's disclosure, will recognize the advantages of this multi-task measurement, which in particular addresses the long-standing problem associated with obtaining sufficient measurement data for segmenting and / or classifying the bottom surface and / or subsurface of a water body, where the echo response varies with sonar frequency. Parallel signals within a single acoustic pulse message are particularly advantageous for bottom segmentation and / or bottom classification measurement tasks, providing echoes from the same backscatterer at multiple frequencies (e.g., see...). Figure 3B-3D ).

[0106] The third multi-task measurement includes a first task of characterizing or segmenting the bottom of the water body and a second task of sounding depth. Typically, the mid-band frequency can be used.

[0107] The first task of characterizing or segmenting the bottom of a water body uses a lower frequency band with CW signals, or in some embodiments, two or three CW signals. The second task of sounding uses a higher frequency band with FM signals. These signals can be transmitted serially or in parallel within a single acoustic pulse. These signals can also be transmitted in corresponding acoustic pulses within a multi-pulse message. Those skilled in the art will recognize the advantages of this multi-tasking measurement after reading the applicant's disclosure. This multi-tasking measurement, in particular, addresses a long-standing problem associated with obtaining measurement data that can be used to characterize or segment the bottom of a water body and sound depth in a single pass.

[0108] The fourth multi-mission measurement includes the first Doppler navigation mission and the second multi-fan depth sounding mission. Typically, the intermediate frequency band is not used. "Multi-fan" can refer to multiple quasi-parallel fans or strips, including a first fan and one or more additional fans turning before and / or after the first fan. For example, a multi-fan mission might use a central athwartship fan perpendicular to the keelline, and quasi-parallel fans on either side of that athwartship fan.

[0109] The first Doppler navigation mission uses a lower frequency band with phase-coded signals, such as Barker codes. The second multi-fan sounding mission uses a higher frequency band with spread-spectrum signals, such as orthogonal coded pulses (OCPs). These signals can be serialized in a single acoustic pulse. Because OCP signals are distinguished by their coding patterns, multiple coded signals can be used to enable corresponding parallel or slightly parallel stripes to acoustically penetrate in a fan-shaped setup. The echoes of the OCP signals are distinguished using the code patterns. These signals can be serialized in a single acoustic pulse or transmitted in corresponding acoustic pulses within a multi-pulse message. Those skilled in the art will recognize the advantages of this multi-mission measurement, which, in particular, addresses long-standing problems associated with along-track detection density, multi-faceted multibeam measurements, and parallel sounding and navigation operations, after reading the applicant's disclosure.

[0110] The fifth multi-task measurement includes a first shallow bottom profiling task and a second depth sounding task. Typically, the intermediate frequency band can be used.

[0111] The first bottom mission uses a lower frequency band with CW signals. The second bottom mission uses a higher frequency band with CW signals. These signals can be transmitted in parallel within a single acoustic pulse message. Alternatively, these signals can be transmitted within corresponding acoustic pulses in a multi-pulse message. Those skilled in the art will recognize the advantages of this multi-mission measurement, which in particular addresses the long-standing problem associated with obtaining sufficient measurement data for shallow bottom profiling and depth sounding, after reading the applicant's disclosure. The parallel transmission of the shallow bottom profiling signal and the depth sounding signal is significantly beneficial for shallow bottom profiling, as the signals return from the same backscatterer (e.g., see...). Figure 3B-3D ).

[0112] The sixth multi-task measurement includes a first water column characterization task and a second water column characterization task. Typically, the intermediate frequency band can be used.

[0113] The first water column mission uses a lower frequency band with CW or FM signals. The second water column mission uses a higher frequency band with CW or FM signals. These signals can be transmitted serially or in parallel within a single acoustic pulse message. These signals can also be transmitted within corresponding acoustic pulses in a multi-acoustic pulse message. Upon reading the applicant's disclosure, those skilled in the art will recognize the advantages of this multi-mission measurement, which in particular addresses the long-standing problem associated with obtaining sufficient water column data for segmenting and / or classifying water column backscatterers, where the echo response varies with sonar frequency. Parallel signals within a single acoustic pulse message are significantly beneficial for water column segmentation and / or classification tasks, providing echoes from the same backscatterer at multiple frequencies.

[0114] The seventh multi-task measurement includes a first water column characterization or segmentation task and a second depth sounding task. Typically, the intermediate frequency band can be used.

[0115] The first water column characterization or segmentation task uses a lower frequency band with CW or FM signals, or in some embodiments, two or three CW or FM signals. The second depth sounding task uses a higher frequency band with FM signals. These signals can be transmitted serially or in parallel within a single acoustic pulse. These signals can also be transmitted in corresponding acoustic pulses within a multi-pulse message. Those skilled in the art, upon reading the applicant's disclosure, will recognize the advantages of this multi-task measurement, which in particular addresses the long-standing problem associated with obtaining measurement data that can be used to characterize or segment water columns and sound depths in a single pass.

[0116] Figures 6A to 6G An exemplary message with a specific signal frequency is shown for multitasking measurement of the 600A600G.

[0117] Figure 6A The first multi-task measurement, including a first remote bathymetry mission and a second high-resolution bathymetry mission 600A, is shown.

[0118] The first long-range sounding mission used a lower frequency band, with the center frequency of the CW or FM signal being approximately 200 kHz and the bandwidths being approximately 5 to 30 kHz and approximately 30 to 60 kHz, respectively.

[0119] The second high-resolution sounding mission uses a higher frequency band, with the center frequency of the CW or FM signal approximately 700 kHz, corresponding to bandwidths of approximately 20 to 60 kHz and approximately 20 to 60 kHz, respectively. These signals can be transmitted in parallel within a single acoustic pulse message (as shown in the figure). Alternatively, these signals can be transmitted within corresponding acoustic pulses in a multi-pulse message.

[0120] Figure 6B The second multi-task measurement of the 600B, which includes three bottom characterization or segmentation tasks, is shown.

[0121] The first bottom characterization or segmentation task uses a lower frequency band, with the CW signal having a center frequency of about 50 kHz and a bandwidth of about 2 to 10 kHz.

[0122] The second bottom characterization or segmentation task uses the mid-frequency band, with the CW signal having a center frequency of approximately 100 kHz and a bandwidth of approximately 2 to 10 kHz.

[0123] The third bottom characterization or segmentation task uses a higher frequency band; the CW signal has a center frequency of approximately 150 kHz and a bandwidth of approximately 2 to 10 kHz. These signals can be transmitted in parallel within a single acoustic pulse message (as shown in the figure). Alternatively, these signals can be transmitted within corresponding acoustic pulses in a multi-acoustic pulse message.

[0124] The center frequencies of 50, 100, and 150 kHz may be shifted to avoid harmonics. For example, if the 50 kHz center frequency is located in the center of a first frequency band, a first harmonic can be avoided by shifting the 50 kHz center frequency close to the frequency increment of the first frequency band width. Similarly, if the 150 kHz center frequency is located in the center of a second frequency band, a second harmonic can be avoided by shifting the 150 kHz center frequency close to the frequency increment of the second frequency band width. As those skilled in the art will understand, other similar changes to the aforementioned center frequencies can also avoid harmonics.

[0125] Figure 6C The third multi-task measurement is shown, including a first bottom characterization or segmentation task and a second bathymetry task 600C.

[0126] The first bottom characterization or segmentation task uses a lower frequency band, with three CW signals having corresponding center frequencies of approximately 50, 150, and 250 kHz. As mentioned above, these center frequencies may be shifted to avoid harmonics. In this context, where multiple signals in corresponding frequency bands are used to complete a single task, this task can be referred to as a multi-band task.

[0127] The second depth sounding mission uses a higher frequency band, with the FM signal having a center frequency of approximately 400 kHz and a bandwidth of approximately 30 to 60 kHz. These signals can be transmitted serially or in parallel within a single acoustic pulse message (as shown in the figure). These signals can also be transmitted within corresponding acoustic pulses in a multi-pulse message. It is worth noting that the phrase "about ... kHz" refers to the manufacturing and operational tolerances associated with the generation, transmission, reception, and / or decomposition of signals by modern sonar equipment used for depth sounding and / or bottom segmentation.

[0128] Figure 6D The fourth multi-task measurement, including the first navigation mission and the second depth sounding mission of the 600D, is shown.

[0129] The first navigation mission uses a lower frequency band, with the center frequency of the phase-coded signal being approximately 100 kHz and the bandwidth being approximately 60 kHz.

[0130] The second depth sounding mission uses a higher frequency band, with the center frequency of the three OSS signals at 400kHz. OSS signals can have similar bandwidths and occupy a common frequency band of approximately 100kHz. In this case, where multiple OSS signals occupy a common frequency band, this can be referred to as a multi-signal band, and the signals within that band can be called signal packets.

[0131] These signals can be sent in messages with a combination of parallel and serial formats, wherein a depth sounding signal is sent, and a navigation signal is sent before or after the depth sounding signal.

[0132] Figure 6E The fifth multi-task measurement is shown, which includes the first shallow bottom profiling mission and the second depth sounding mission 600E.

[0133] The first shallow bottom profile mission uses a lower frequency band, with the center frequency of the CW signal in the range of approximately 10 to 30 kHz, which is 15 kHz in this case, and a bandwidth of approximately 1 kHz.

[0134] The second sounding mission uses a higher frequency band, with the CW signal having a center frequency of approximately 200 kHz and a bandwidth of approximately 20 to 60 kHz. These signals can be transmitted in parallel within a single acoustic pulse message (as shown in the figure). Alternatively, these signals can be transmitted within corresponding acoustic pulses in a multi-pulse message.

[0135] Figure 6F The sixth multi-task measurement, including the first and second water column tasks of the 600F, is shown.

[0136] The first water column mission utilized a lower frequency band, where the center frequency of the CW or FM signal was approximately 100 kHz, with corresponding bandwidths of approximately 10 to 20 kHz and approximately 10 to 30 kHz.

[0137] The second water column mission uses a higher frequency band, with the center frequency of the CW or FM signal approximately 150 kHz, corresponding to bandwidths of approximately 10 to 20 kHz and approximately 10 to 30 kHz, respectively. These signals can be transmitted in parallel within a single acoustic pulse message (as shown in the figure). Alternatively, these signals can be transmitted within corresponding acoustic pulses in a multi-pulse message.

[0138] Figure 6G The seventh multi-task measurement is shown, which includes the first water column mission and the second 600G depth sounding mission.

[0139] The first water column mission uses a lower frequency band, with the center frequency of the CW or FM signal being approximately 100 kHz, and the corresponding bandwidth being approximately 10 to 30 kHz and approximately 30 to 60 kHz.

[0140] The second depth sounding mission uses a higher frequency band, with the center frequency of the CW or FM signal approximately 400 kHz, and the corresponding bandwidth approximately 20 to 60 kHz and approximately 30 to 60 kHz, respectively. These signals can be transmitted in parallel within a single acoustic pulse message (as shown in the figure). These signals can also be transmitted within corresponding acoustic pulses in a multi-pulse message. The applicant notes that, in combination Figures 6A to 6E The center frequency of the mentioned signal is an example. In various embodiments, these center frequencies can vary within the range of + / -5%, + / -10%, + / -25%, and / or + / -50%. The applicant notes that, in combination Figures 6A to 6EThe bandwidth of the signal mentioned is an example. In various embodiments, these bandwidths can vary within the range of + / -5%, + / -10%, + / -25%, and / or + / -50%.

[0141] While various embodiments of the invention have been described above, it should be understood that these embodiments are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. Thus, the breadth and scope of the invention should not be limited by the exemplary embodiments described above, but should be defined solely by the following claims and their equivalents.

Claims

1. A measurement system for performing multiple tasks in each message, the measurement system comprising a multibeam echo sounder system for mounting on a watercraft, the measurement system comprising: The multibeam echo sounder system's single acoustic transceiver works in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver is configured to use a transmit beamformer and a receive beamformer; The single projector array and the single hydrophone array are configured such that a single elongated strip, through which sound is transmitted by the single projector array, intersects with the beams of the multiple hydrophone arrays. The single acoustic transceiver uses multiple non-overlapping frequency bands with corresponding bandwidths and center frequencies, numbering N. The individual acoustic transceiver synthesizes a single transmitter message, which contains one or more signals from each of the plurality of non-overlapping frequency bands, the signals supporting multiple tasks; A single transmitter message excites the single projector array such that a single elongated strip at the bottom of the water body is penetrated by each signal sound in the single transmitter message, and multiple message echoes from the scattering center of the sound penetration are received by the single hydrophone array. as well as The multiple frequency bands support the corresponding tasks. The multiple frequency bands are wide-spaced to facilitate the identification of one or more frequency-dependent characteristics of the scattering centers of the sound penetration by a measurement system.

2. The measurement system according to claim 1, wherein, The scattering center includes one or more of the following: a surface scattering center located at the bottom of the water body, a volume scattering center located at the shallow bottom of the water body, and a volume scattering center located in the water column of the water body.

3. The measurement system of claim 1, wherein, This facilitates the identification of measurement systems for backscattering intensity with a specific projection angle relative to the vertical.

4. The measurement system of claim 1, wherein, This facilitates the identification of measurement systems for average angular backscatter intensity.

5. The measurement system of claim 1, wherein, Any two center frequencies are separated by at least twice the narrowest bandwidth of the corresponding signal bandwidth or by at least 30% of the lower of the two center frequencies.

6. The measurement system of claim 1, wherein, The bottom of the water body is acoustically penetrated substantially simultaneously by each of the signals in the message.

7. The measurement system of claim 1, wherein, The message includes multiple signals in parallel.

8. The measurement system according to claim 1, In the transmitter of the single acoustic transceiver, further comprising: N signal generators are used to generate signals included in the message; as well as In the receiver of the single acoustic transceiver, for each hydrophone, there is also a parallel input filter bank, which includes N digitally implemented bandpass filters having corresponding center frequencies corresponding to the center frequencies of the frequency bands.

9. The measurement system according to claim 1, further comprising: The first mission facility for depth measurement and the second mission facility for depth measurement; The first mission facility uses a frequency band centered at a lower frequency within the frequency band; and... The second mission facility uses one of the frequency bands centered at a higher frequency. Among them, the center frequency of the lower frequency band is lower than the center frequency of the higher frequency band.

10. The measurement system of claim 9, wherein, The single transmitter message includes one or both of a continuous wave signal and a frequency modulation signal.

11. The measurement system according to claim 9, wherein, The message echo includes a first task backscatter from a first task echo source and a second task backscatter from a second task echo source, wherein the second task echo source is a subset of the first task echo source.

12. The measurement system according to claim 8, further comprising: The first, second, and third mission facilities are used for bottom segmentation or characterization of water bodies. The first mission facility uses a first frequency band within a first frequency range in the frequency band; The second mission facility uses the second frequency band within the second frequency range of the frequency band; and... The third mission facility uses a third frequency band within the third frequency range of the frequency band; The center frequency of the second frequency band is higher than the center frequency of the first frequency band and lower than the center frequency of the third frequency band.

13. The measurement system of claim 12, wherein, The statistically significant differences between the frequency-dependent characteristics of backscattering are used to deconstruct the backscattering data generated by the transmitted messages into backscattering datasets corresponding to the first task, the second task, and the third task.

14. The measurement system according to claim 12, For each signal, also comprising: The corresponding backscatter dataset is derived from the backscatter data; For any one of the signals in the first frequency band, the second frequency band, or the third frequency band, the corresponding backscatter dataset is used to divide the bottom of the water body at certain intervals along the strips through which the signal is acoustically penetrated; For another signal in the first frequency band, the second frequency band, or the third frequency band, the corresponding backscatter dataset is used to refine the earlier segmentation; and, For another signal in the first frequency band, the second frequency band, or the third frequency band, the corresponding backscatter dataset is used to refine at least one of the earlier segments.

15. The measurement system according to claim 12, further comprising: The fourth mission facility for depth sounding; and, The fourth mission facility uses the fourth frequency band within the fourth frequency range of the frequency band.

16. The measurement system according to claim 8, further comprising: The first mission facility for navigation and the second mission facility for depth sounding; The first mission facility uses a first frequency band within a first frequency range; and... The second mission facility uses the second frequency band within the second frequency range of the frequency band.

17. The measurement system of claim 16, wherein, At least one phase-coded signal exists in the first frequency band, and multiple orthogonal spread spectrum signals exist in the second frequency band.

18. A sonar system, comprising: A multibeam echo sounder system uses a single acoustic transceiver to work in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver uses a transmit beamformer and a receive beamformer. The single acoustic transceiver and the single projector array are configured to form a narrow transmission beam, and The individual acoustic transceiver and the individual hydrophone array are configured to form a narrow receiving beam. The system is configured to include: a) continuous transmission of a corresponding transmission beam, the corresponding transmission beam transmitting one or more corresponding signals in a corresponding frequency band; b) a first transmission beam intersecting with a first group of multiple receiving beams, and a second transmission beam intersecting with a second group of multiple receiving beams; and c) a receiving beam transmitting an echo from a scattering center through which the transmission beam penetrates.

19. The sonar system according to claim 18, wherein: The first transmission is the first acoustic pulse that generates the first transmission beam; The second transmission is the second acoustic pulse that generates the second transmission beam; as well as The acoustic pulse period includes the acoustic pulse and the reception of the echo from that acoustic pulse.

20. The sonar system of claim 19, further comprising: A third transmission or acoustic pulse is generated by generating a third transmission beam. The third transmission beam transmits a third signal in a third frequency band, which does not overlap with the first or second frequency band.

21. The sonar system of claim 20, further comprising: The first, second, and third sound pulses used in the first, second, and third sound pulse cycles; as well as The second sound pulse period is between the first sound pulse period and the third sound pulse period, the end of the first sound pulse period is adjacent to the beginning of the second sound pulse period, and the beginning of the third sound pulse is adjacent to the end of the second sound pulse.

22. The sonar system of claim 20, further comprising: The first, second, and third sound pulses used in the first, second, and third sound pulse cycles; as well as The second sound pulse period is between the first sound pulse period and the third sound pulse period, the end of the first sound pulse period is substantially adjacent to the beginning of the second sound pulse period, and the beginning of the third sound pulse is substantially adjacent to the end of the second sound pulse.

23. The sonar system of claim 21 or 22, wherein, The first acoustic pulse is time-spaced from the second acoustic pulse, and the second acoustic pulse is time-spaced from the third acoustic pulse.

24. The sonar system according to claim 18, wherein: The first transmission is the transmission of the first message; The second transmission is the transmission of the second message; and A message cycle includes the message being sent and the echo being received from that message.

25. The sonar system of claim 24, further comprising: For a third transmission that generates a third transmission beam and a third message, the third transmission beam transmits at least one third signal in a third frequency band, which does not overlap with the first or second frequency band; The first message, second message, and third message used in the first message cycle, the second message cycle, and the third message cycle; as well as The second message cycle is between the first message cycle and the third message cycle, with the end of the first message cycle adjacent to the start of the second message cycle, and the start of the third message cycle adjacent to the end of the second message cycle.

26. The sonar system of claim 24, further comprising: The first transmission is the transmission of the first signal; The second transmission is the transmission of the second signal; as well as For the third transmission of a third message that generates a third transmission beam, the third transmission beam transmits a third signal in a third frequency band, which does not overlap with the first or second frequency band.

27. A sonar system for installation on a watercraft, the sonar system comprising: A single acoustic transceiver of a multibeam echo sounder system works in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver; The single acoustic transceiver uses a transmit beamformer and a receive beamformer; Multiple signals of number X in the corresponding frequency band support X measurement functions; X signals are distributed across Y corresponding transmissions; Each of the Y transmissions from the transmitter causes the projector to emit sound waves; The sound waves are focused on a narrow region so that the scattering center within the narrow region is penetrated by the sound. The receiver and hydrophone form multiple receiving beams, which intersect the elongated region at multiple locations; as well as The receiver acquires echo data from the scattering center at the intersection point. Among them, the frequency-dependent characteristics of the scattering center of sound penetration in the echo enable the performance of measurement functions.

28. A sonar system for installation on a watercraft, the sonar system comprising: A single acoustic transceiver of a multibeam echo sounder system works in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver; The single acoustic transceiver uses a transmit beamformer and a receive beamformer; There are X signals in the corresponding frequency band, and these X signals are distributed across Y corresponding transmissions; Each of the Y transmissions from the transmitter causes the projector to emit sound waves; The sound waves are focused on a narrow region so that the scattering center within the narrow region is penetrated by the sound. The receiver and hydrophone form multiple receiving beams, which intersect the elongated region at multiple locations; as well as The receiver acquires echo data from the scattering center at the intersection point. The echo data in each frequency band is processed so that, at each frequency, the frequency-dependent characteristics of one or more of the scattering centers enable the execution of measurement functions.

29. A sonar measurement system, comprising: A multibeam echo sounder system uses a single acoustic transceiver to work in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver uses a transmit beamformer and a receive beamformer. The single acoustic transceiver and the single projector array are configured to form a long, narrow transmission beam. The single acoustic transceiver and the single hydrophone array are configured to form multiple elongated receiving beams; The receiving beam intersects with the transmitting beam to receive the echo from the scattering center of the sound penetration of the transmitting beam; as well as The system is configured to include an operating mode in which the transmission beam transmits a message consisting of N>1 different signals in different non-overlapping frequency bands.

30. A sonar system for installation on a watercraft, the sonar system comprising: A single acoustic transceiver of a multibeam echo sounder system works in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver; The single acoustic transceiver uses a transmit beamformer and a receive beamformer; The transmitter is configured to transmit a transmission that causes the single projector array to emit sound waves. The sound waves are focused on a narrow region so that the scattering center within the narrow region is penetrated by the sound. The receiver and the single hydrophone array form multiple receiving beams, which intersect the elongated region at multiple locations; as well as The receiver acquires echo data from the scattering center at the intersection point. The transmission includes N>1 signals in corresponding non-overlapping frequency bands, which enable the execution of a measurement function that indicates one or more frequency-dependent characteristics of the scattering centers penetrated by sound.

31. A measurement system for performing multiple tasks in each message, the measurement system comprising a multibeam echo sounder system for mounting on a watercraft, the measurement system comprising: A multibeam echo sounder system uses a single acoustic transceiver to work in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver. The single acoustic transceiver uses a transmit beamformer and a receive beamformer. The single projector array and the single hydrophone array are configured to form a Mills cross, such that the strips that are sound-penetrated by the single projector array intersect with the beams of the multiple hydrophone arrays. The single acoustic transceiver is used in multiple non-overlapping frequency bands with corresponding bandwidths and center frequencies, numbering N. The single acoustic transceiver is used to synthesize a single transmitter message, the single transmitter message containing one or more signals from each of the plurality of non-overlapping frequency bands, the signals supporting multiple tasks; A single transmitter message is used to excite the single projector array such that the stripe at the bottom of the water body is penetrated by each signal sound in the single transmitter message, and the message echo from the scattering center of the sound penetration is returned to the single hydrophone array; and The multiple frequency bands are used to support the corresponding tasks, and the multiple frequency bands are widely spaced to facilitate the identification of one or more frequency-dependent characteristics of the scattering centers of the sound penetration by the measurement system.

32. A measurement system for performing multiple tasks in each message, the measurement system comprising a multibeam echo sounder system for mounting on a watercraft, the measurement system comprising: A single acoustic transceiver of a multibeam echo sounder system works in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver; The single acoustic transceiver uses a transmit beamformer and a receive beamformer. The single projector array and the single hydrophone array are configured to form a Mills cross, such that the strips that are sound-penetrated by the single projector array intersect with the beams of the multiple hydrophone arrays. The single acoustic transceiver is used in multiple non-overlapping frequency bands with corresponding bandwidths and center frequencies, numbering N. The single acoustic transceiver is used to synthesize a single transmitter message, the single transmitter message containing one or more signals from each of the plurality of non-overlapping frequency bands, the signals supporting multiple tasks; A single transmitter message is used to excite the single projector array such that the stripe at the bottom of the water body is penetrated by each signal sound in the single transmitter message, and the message echo from the scattering center of the sound penetration is returned to the single hydrophone array; and The multiple frequency bands are used to support the corresponding tasks, and the multiple frequency bands are widely spaced to facilitate the identification of one or more frequency-dependent characteristics of the scattering centers of the sound penetration by the measurement system.

33. A measurement system for performing multiple tasks in each message, the measurement system comprising a multibeam echo sounder system for mounting on a watercraft, the measurement system comprising: A multibeam echo sounder system uses a single acoustic transceiver to work in conjunction with a single projector array and a single hydrophone array, the single projector array having multiple projectors and the single hydrophone array having multiple hydrophones. The single acoustic transceiver includes a transmitter and a receiver. The single acoustic transceiver uses a transmit beamformer and a receive beamformer. The single projector array and the single hydrophone array are configured such that the strips through which the sound is transmitted by the single projector array intersect with the beams of the multiple hydrophone arrays. The single acoustic transceiver is used in multiple non-overlapping frequency bands with corresponding bandwidths and center frequencies, numbering N. The single acoustic transceiver is used to synthesize a single transmitter message, the single transmitter message containing one or more signals from each of the plurality of non-overlapping frequency bands, the signals supporting multiple tasks; A single transmitter message is used to excite the single projector array such that the strip at the bottom of the water body is penetrated by each signal sound in the single transmitter message, and the message echo from the scattering center of the sound penetration is returned to the single hydrophone array. as well as The multiple frequency bands are used to support the corresponding tasks, and the multiple frequency bands are widely spaced to facilitate the identification of one or more frequency-dependent characteristics of the scattering centers of the sound penetration by the measurement system.

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