[go: up one dir, main page]

WO2008105932A2 - Système et procédé pour sonar frontal - Google Patents

Système et procédé pour sonar frontal Download PDF

Info

Publication number
WO2008105932A2
WO2008105932A2 PCT/US2007/078577 US2007078577W WO2008105932A2 WO 2008105932 A2 WO2008105932 A2 WO 2008105932A2 US 2007078577 W US2007078577 W US 2007078577W WO 2008105932 A2 WO2008105932 A2 WO 2008105932A2
Authority
WO
WIPO (PCT)
Prior art keywords
beams
region
horizontal
generate
complex samples
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/US2007/078577
Other languages
English (en)
Other versions
WO2008105932A3 (fr
Inventor
Paul Kraeutner
Wen Xu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Teledyne RD Instruments Inc
Original Assignee
Teledyne RD Instruments Inc
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 Teledyne RD Instruments Inc filed Critical Teledyne RD Instruments Inc
Publication of WO2008105932A2 publication Critical patent/WO2008105932A2/fr
Publication of WO2008105932A3 publication Critical patent/WO2008105932A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/52003—Techniques for enhancing spatial resolution of targets

Definitions

  • the present invention relates to acoustic transducers and beamformers that form simultaneous multiple beams in multiple planes.
  • UUVs Unmanned Underwater Vehicles
  • hydrographic mapping a popular tool in ocean observation, hydrographic mapping, offshore engineering, as well as military applications such as mine countermeasure, anti-submarine warfare, and environmental monitoring/assessment.
  • mine countermeasure a mine countermeasure
  • anti-submarine warfare and environmental monitoring/assessment.
  • This trend to increased use of such UUVs has generated new opportunities as well as challenges for acoustic sensor system design.
  • the integrated sonar systems must be low-power, compact-size, and in some applications, expendable.
  • Most existing commercial systems do not meet these requirements, nor can they be readily adapted to meet the requirements.
  • FLS Forward looking sonar
  • Those applications in turn require that the FLS be capable of high resolution discrimination of acoustic echoes in both the horizontal and vertical directions. Achieving high resolution in both dimensions has generally only been possible with large complex systems that employ profuse numbers of sensors and that are not only expensive but that also consume prohibitive amounts of power to make them viable on small UUVs and in other applications.
  • One embodiment includes a method of imaging a region.
  • the method comprises transmitting at least one acoustic pulse and receiving a portion of the pulse scattered from a region via an acoustic transducer having N elements, and.
  • the method further comprises generating a multi-channel signal based on the received portion of the pulse scattered from the region and sampling the scattering signal to generate a plurality of complex samples.
  • the method further comprises simultaneously forming a plurality of beams in a horizontal plane based on the complex samples.
  • the method further comprises processing the plurality of complex samples to obtain image data comprising angles of arrival from M scattering components in a vertical plane.
  • the number of scattering components M is less than N and the horizontal plane and the vertical plane are substantially orthogonal.
  • the method may optionally include generating an image based on the image data.
  • One embodiment includes a system for imaging a region.
  • the system includes at least one transducer configured to transmit at least one acoustic pulse and at least one transducer configured to receive a portion of the pulse scattered from a region.
  • the at least one receiving transducer has N elements.
  • the system further includes a receiver configured to generate a multi-channel signal based on the received portion of the pulse scattered from the region, and sample the scattering signal to generate a plurality of complex samples.
  • the system further includes a beamformer configured to simultaneously form a plurality of beams in a horizontal plane based on the complex samples.
  • the system further includes a processor configured to process the plurality of complex samples to obtain image data comprising angles of arrival from M scattering components in a vertical plane for each horizontal beam.
  • the number of scattering components M is less than N, and the horizontal plane and the vertical plane are substantially orthogonal.
  • the processor may also be configured to generate an image based on the image data.
  • One embodiment includes an underwater vehicle comprising a vehicle frame, a sonar system, and a housing configured to secure the sonar system to the vehicle frame.
  • the sonar system includes at least one transducer configured to transmit at least one acoustic pulse and at least one transducer configured to receive a portion of the pulse scattered from a region.
  • the at least one receiving transducer has N elements.
  • the system further includes a receiver configured to generate a multi-channel signal based on the received portion of the pulse scattered from the region, and sample the scattering signal to generate a plurality of complex samples.
  • the system further includes a beamformer configured to simultaneously form a plurality of beams in a horizontal plane based on the complex samples.
  • the system further includes a processor configured to process the plurality of complex samples to obtain image data comprising angles of arrival from M scattering components in a vertical plane for each horizontal beam.
  • the number of scattering components M is less than N, and the horizontal plane and the vertical plane are substantially orthogonal.
  • the processor may also be configured to generate an image based on the image data.
  • One embodiment includes a system for imaging a region.
  • the system includes means for transmitting at least one acoustic pulse and means for receiving a portion of the pulse scattered from a region.
  • the receiving means has N elements.
  • the system further includes means for processing the received portion of the pulse.
  • the means is configured to generate a multi-channel signal based on the received portion of the pulse scattered from the region, and sample the scattering signal to generate a plurality of complex samples.
  • the system further includes means for simultaneously forming a plurality of beams in a horizontal plane based on the complex samples.
  • the system further includes means for processing the plurality of complex samples to obtain image data comprising angles of arrival from M scattering components in a vertical plane for each horizontal beam.
  • the number of components M is less than N, the horizontal plane and the vertical plane are substantially orthogonal.
  • the processing means may be further configured to generate an image based on the image data.
  • Figure 1 illustrates a beam footprint versus transmit pulse footprint according to one embodiment.
  • Figure 2 illustrates one embodiment of a three-dimensional forward looking imaging sonar.
  • Figure 3 is a top level schematic block diagram of a sonar system according to one embodiment.
  • Figure 4 is a schematic block diagram that further illustrates a portion of the sonar system of Figure 3 in further detail.
  • FIG. 5 is a schematic block diagram that further illustrates another portion of the sonar system of Figure 3 in further detail.
  • Figure 6 is a flowchart that illustrates one example of a method of generating sonar images according to one embodiment.
  • Figures 7A-D illustrate lakebed imaging and profiling test results for one embodiment.
  • Figure 7A is a 2D profile of relatively flat lakebed and surface buoy (obstacle) located at 27 m range.
  • Figure 7B is 2D depth profile of upward sloping lakebed and surface multipath.
  • Figure 7C is an upward sloping lakebed bathymetry ahead of sonar assembled from individual depth profiles associated with each beam.
  • Figure 7D is a 2D backscatter image of upward sloping lakebed ahead of sonar assembled from backscatter in each beam.
  • Embodiments include a system and method for imaging and mapping the region of various looking directions from a stationary or mobile platform to which the system is attached.
  • One embodiment uses angle-of-arrival estimation in conjunction with beamforming under various transducer array configurations to either improve system resolution or reduce system complexity.
  • Embodiments may include a novel electronics architecture configured to provide low power operation in a compact space efficient device.
  • one embodiment of the method and apparatus provides a low- power, compact-size solution for many three-dimensional imaging and mapping applications particularly with small mobile platforms such as unmanned underwater vehicles.
  • a Multi-Beam Echo Sounder is a downward and side looking sonar that is configured to determine the range to the seafloor in a number of discrete beams spanning a swath underneath and to port and starboard of the vehicle's forward path.
  • Embodiments may also include a system and method that is a low-power, compact-size solution for many three-dimensional imaging and mapping applications particularly with small mobile platforms such as Unmanned Underwater Vehicles.
  • the apparatus performs array-based imaging and mapping.
  • the apparatus has a transmit transducer array projecting a signal into the field, a receive transducer array collecting scattered signals from the field of interest, and an electronics subsystem handling generation and processing of signal to/from the transducer arrays.
  • the apparatus has a desirable electronics architecture of power and space efficient, featuring a time-division multiplexing multi-channel sonar receiver, a high-speed low-power Field Programmable Gate Array (FPGA)-based data acquisition system, and a digital signal processing chain consisting of low-power highspeed digital signal processor (DSP) and FPGA.
  • DSP digital signal processor
  • One embodiment of a method implements angle-of-arrival estimation to add vertical information in conjunction with beamforming in various ways for transducer arrays of various configurations.
  • one embodiment of the method combines angle-of-arrival estimation in the vertical plane with beamforming in the horizontal plane.
  • the method can significantly reduce the number of transducer array elements while achieving the same or better resolution performance compared to a conventional beamforming-based system.
  • angle-of-arrival estimation and beamforming are used as complementary tools applied in the same angular dimension. Beamforming is employed to obtain first-look data results; angle-of-arrival processing is then applied in a subsequent step to achieve sub-beam width resolution. This two-pass approach will be particularly beneficial in improving system performance in the outer beams.
  • both beamforming and angle-of-arrival estimation are terms that describe methods for measuring the directional origin of propagating acoustic waves. Both methods make use of an array of sensors to simultaneously measure a propagating wave front at several discrete locations.
  • the sensor array is comprised of individual transducer elements, typically organized along a line with equal spacing between elements.
  • Beamforming is an approach used in most existing electronic-scanning acoustic imaging and mapping systems. Generally, however, the angular resolution is inversely proportional to the array aperture size. For example, in order to achieve a 1.5° beam in one plane, with reasonably low sidelobes (i.e. leakage from directions outside the main beam) approximately 88 elements and therefore 88 receive channels are required. Thus, the required number of elements for a two-dimensional beamforming-based system is significant.
  • an angle-of-arrival estimation approach directly estimates the directional origin of the backscatter by tracking the instantaneous position of the transmit pulse on the seafloor. Since the pulse footprint is, in general, much smaller than can be practically achieved by beamforming, the advantage in terms of achievable resolution of the angle-of-arrival estimation approach is substantial.
  • an angle-of-arrival estimation-based system works well in typical geometries of shallow water vertical profiling, where only a discrete set of simultaneous signal arrivals presents, including sea-floor vertical features, water column targets above the seafloor, surface backscatter, and multipath.
  • One embodiment includes a feature of combining beamforming and angle-of-arrival estimation for use in two-dimensional or three-dimensional imaging or mapping. The first of such combinations is for three-dimensional forward looking imaging, as shown in Figure 2.
  • Figure 2 illustrates one embodiment of a three-dimensional forward looking imaging sonar 1042 as embodiment in a underwater vehicle 102.
  • directional information is required in two dimensions. It has been found that the multiple-angle-of-arrival estimation approach is well suited to sorting backscatter arrivals in the vertical plane. Therefore, angle-of-arrival estimation is also well suited to forward-looking sonar requirements such as seabed profiling and separation of multipath from direct path seabed and obstacle arrivals in shallow water.
  • beamforming is applied in the horizontal plane (using a relatively large number of array elements in that dimension) and to apply angle- of-arrival processing in the vertical plane (using a small number of array elements in the vertical dimension). Implementations may repeat this procedure in multiple simultaneous horizontal look directions and therefore produces an angle-of-arrival result simultaneously in each horizontal look direction.
  • a transmitted pulse 108 propagating in each beam 110 intersects the seafloor 111 at time t at a range R (t) and the elevation angle ⁇ l (t).
  • the acoustic pulse also intersects an example target 112, e.g., a mine-like target in the water column at an elevation angle of ⁇ M (t).
  • Backscatter 1 14 from the seafloor and the mine-like target are subsequently received by the sonar array 104 mounted on the nose of the vehicle 102 and angle-of-arrival processing is applied.
  • Angle-of-arrival processing produces an estimate of the backscatter angles-of-arrival ⁇ l(t) - O M (t) along with their associated amplitudes.
  • the number of concurrent arrivals that can be resolved by angle-of-arrival processing is a function of N, the number of rows in the array and is typically up to N-I .
  • the procedure for producing a three-dimensional image then is to apply angle-of-arrival processing to each horizontal beam in order to provide N-I elevation angles and associated amplitudes at each range step in each beam.
  • the backscatter may be plotted in three- dimensional space using spherical coordinates (i.e. range, azimuth, elevation ) relative to the vehicle position.
  • multi-beam bottom mapping directional information is only required in one plane (e.g. a multibeam echo sounder with downward looking narrow beams distributed athwart ship).
  • beamforming may be employed to obtain first-look data results, in a similar fashion to other multibeam systems.
  • This two-pass approach can be particularly beneficial in improving system performance in the outer beams as shown in Figure 1.
  • angle-of- arrival and beamforming are used as complementary tools applied in the same angular dimension.
  • FIG. 3 is a top level schematic block diagram of the sonar system 104 according to one embodiment.
  • the sonar system 104 comprises an obstacle avoidance sonar.
  • the sonar system 104 is organized Embodiments such as illustrated in Figure 3 may also include a versatile sonar architecture which focuses specifically on minimization of size and power.
  • the sonar system 104 includes a number of stackable modules, which in one embodiment, are each a circuit card assemblies (CCAs).
  • CCAs circuit card assemblies
  • the functionality discussed herein with reference to these CCAs may be distributed in any suitable arrangement of circuits, processors, or other components.
  • the various illustrative CCAs, logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • a general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
  • a processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
  • one or more of CCAs are implemented using, for example, the VHDL logic device programming language under an environment such as that provided by the Xilinx ISE Foundation.
  • a carrier CCA 302 provides interface connectors for external control and power from a source such as a submersible vehicle or a tether to another control source such as boat, buoy, or pier.
  • the carrier CCA 302 also provides output data from the sonar system back to that control source.
  • the carrier CCA 302 provides power distribution and a mechanical mounting structure for all other CCA's.
  • the carrier CCA 302 also provides the control signals to a digital signal processor (DSP) CCA 304.
  • the physical package comprises a compact CCA stack mounted on the carrier CCA 302, which fits comfortably into an unmanned underwater vehicle payload section measuring 7.5" in diameter by 6" in length.
  • the total power consumption in one embodiment is about 10 watts.
  • the CCA architecture provides signal processing flexibility and its inherent power and size efficiency. It is to be recognized that additional processing capabilities can be easily and incrementally added by incorporating additional DSP CCAs 304, each connected via, for example, high speed serial ports.
  • the interfaces such as a submersible vehicle
  • the DSP CCA 304 generates transmit signals and provides those signals to a transmitter CCA 306.
  • the transmitter 306 then drives one or more transmit arrays 308 to transmit sonar pulses.
  • the sonar pulses may have an operating frequency of about 100 kHz. In another embodiment, the sonar pulses may have an operating frequency of about 150 kHz. In other example embodiments, the sonar pulses may have an operating frequency of between about 50 kHz and 600 kHz
  • Returned portions of the sonar pulses are received by one or more receive arrays 312. Signals provided by the receive arrays 312 are amplified and partially processed by a receiver CCA 314. The receiver CCA 314 and the transmitter CCA 306 may be driving by pulse timing data provided by the DSP CCA 304. Partially processed return data is provided to a data acquisition CCA 316 that further processes the return signals and provides the data back to the DSP CCA 304 for detection and output processing. The processed return data is then output via the carrier CCA 302. Depending on the embodiment, the return data output via the carrier CCA 302 may include one or more of image data or partially processed return data.
  • the receive arrays 312 comprises a two-dimensional array transducer such as disclosed in U.S. Patent No. 5,808,967, which is hereby incorporated by reference in its entirety.
  • the transducer array 308 and receiver array 312 are a single transducer array that is switched between transmit and receive operation.
  • One or both of the transducer arrays 308 and 312 may comprise a series of independent but closely spaced (e.g., within a half wavelength) horizontal line arrays, each capable of being steered in the horizontal plane.
  • the transmit arrays 308 comprises three transducer elements, a central transducer element and two additional elements on either side of the central element, each positioned at an angle with respect to the central transducer element. In one embodiment, the angle is between 5 and 25 degrees. In one embodiment, the offset angle of each of the additional transducer elements is 15 degrees.
  • FIG. 4 is a schematic block diagram that further illustrates a portion of the sonar system 104 in further detail.
  • the carrier CCA 302 includes power supplies 322, e.g., digital and analog power supplies, and data interfaces 324.
  • the data interfaces 324 include one or more data interfaces such as IEEE 1394, USB, RS- 232, and/or Ethernet for communicating with other CCAs of the sonar system 104.
  • one or more of the CCAs may include a Micro-line bus for inter-CCA or external communication.
  • the DSP CCA 304 includes a high-speed, low- power digital signal processor along with a complement of data interfaces 342 (e.g., RS232 and IEEE 1394) with which to communicate with the external systems and with other CCAs.
  • the DSP CCA 304 is configured to generate transmit signals and for angle- of-arrival processing via a detection and output processing module 344.
  • a receive beamformer 346 simultaneously forms horizontal beams based on data received from a transmit control module 348 and the data acquisition CCA 316 via a receiver interface bus 350. Alternatively, or in addition, the receive beamformer 346 may generate such beams in sequence for a scan of an area.
  • the receiver interface bus 350 may be any suitable data bus.
  • the transmit control module 348 generates transmit waveforms for, and provides transmit control to, the transmitter CCA 306 via a transmitter interface bus 354.
  • the receiver interface bus 350 and the transmitter interface bus 354 may be embodied as any suitable data or signal bus, including serial or parallel data interfaces.
  • a timing generator circuit or module 352 provides a ping clock and a ping reset signal to the transmitter CCA 306 and the receiver CCA 314.
  • the transmitter CCA 306 amplifies the transmit waveform generated by the DSP CCA 304 and drives the transmit array 308 under the control of the DSP CCA 304.
  • the transmitter CCA 306 includes a control module 362, a transmit buffer 364, and one or more transmit amplifiers 366 that provide sonar pulses to the transmit arrays 308.
  • the control module 362 receives ping timing signals from the DSP CCA 304 and controls the transmit buffer 364 based on the timing signals.
  • the transmit buffer 364 receives waveforms for transmission from the DSP CCA 304 and provides those signals to the transmit amplifiers 366.
  • Figure 5 is a schematic block diagram that further illustrates another portion of the sonar system 104 in further detail.
  • the receive array 312 comprises a 4x12 array providing 48 channels of data.
  • the receive array 312 comprises 96 horizontal by 6 vertical transducer elements. It is to be recognized that as compared to a system that does not include
  • the receiver CCA 314 may comprise a single CCA or a number of stacked CCAs 314, each configured to process a number of channels, e.g., 12 channels per CCA.
  • one example system 104 includes 12 receive channels per receiver CCA 314. Each receives channel interfaces with each individual transducer element. Each channel passes through a preamplifier 372 and an analog band pass filter (BPF) 374.
  • BPF band pass filter
  • a group, e.g., 12, receive channels are multiplexed via a multiplexer 376 into a single low-power broadband time varying gain (TVG) amplifier 378.
  • TVG amplifiers 378 for two such set of 12 channels are illustrated in the example of Figure 5.
  • Additional TVG amplifiers 378 may amplify the remaining 24 channels.
  • the signals from each of the TVG amplifiers 378 are passed through analog low pass filters 379 and to the data acquisition CCA 316.
  • the outputs of, for example, two of the TVG amplifiers are multiplexed into a single analog output so that the TVG amplifier outputs of 48 multiplexed channels can be provided to the data acquisition CCA 316 via two multiplexed analog outputs as illustrated in Figure 5.
  • the data acquisition CCA 316 receives the multiplexed signals from the receiver CCA 314.
  • the data acquisition CCA 316 is stacked on the DSP CCA 304.
  • the data acquisition CCA 316 which may comprise a single CCA 316, or a stack of two or more CCAs 316.
  • An example of the data CCA 316 includes two analog-to-digital converter (ADC) channels 384 that receives signals from the TVGs 378 of the receiver CCA 314, two digital-to-analog (DAC) channels 382 that provide gain control for the TVGs 378 and a lM-gate FPGA.
  • ADC analog-to-digital converter
  • DAC digital-to-analog
  • the onboard FPGA may be used to perform receive channel de-multiplexing, complex demodulation, and signal-band noise filtering (i.e. digital filtering), beamforming and decimation or any other processing including that discussed with reference to the DSP CCA 304 to provides signal processing flexibility along with power and size efficiency.
  • the signals from the receiver CCA are sampled at the ADCs 384 and demultiplexed via a demultiplexer 386.
  • Digital low pass filters 388 are then applied to each of the channels.
  • the channels are then multiplexed via a digital multiplexer 390 and provided to the DSP CCA 304 for further processing.
  • the data acquisition CCA 316 may include a data sampling clock that is configured to provide timing control to the DSP CCA 304.
  • the data acquisition CCA 316 generates two interrupts that are provide to the DSP CCA 304, one when ping starts and one when ping stops.
  • the DSP CCA 304 may then use the interrupt signals to synchronize the ping operation sequence.
  • the various blocks or modules described with reference to the various CCAs 302-316 include functions that may in various embodiments be reallocated depending on the capabilities of the hardware used to implement the CCAs. In one embodiment, a single board may be used. In other embodiments, the functionality may be redistributed. For example, the functions of the receive beamformer 346 may be performed by the data acquisition CCA 316.
  • FIG. 6 is a flowchart that illustrates one example of a method 600 of generating sonar images according to one embodiment.
  • the method 600 is performed using the system illustrated in Figures 3-6.
  • the method 600 beings at a block 602 in which the transmit transducer array 308, transmits one or more acoustic pulses.
  • the receiver array 310 receives a portion of the pulse that is scattered from a region, e.g., a target region of a body of water.
  • the receive array 310 may include N transducer elements.
  • the receiver CCA 314, and/or the data acquisition CCA 316 generate a multi-channel signal based on the received portion of the pulse scattered from the region.
  • the receiver CCA 314 may be configured to filter the received portion of the pulse scattered from the region using the analog BPF 374 and the to generate a plurality of channel signals, each signal corresponding to one of a plurality of frequency bands.
  • Such an example of the receiver CCA 314 may be further configured to amplify each of the channel signals via the TVG 378 for a portion of a time period, the portion being less than all of the time period, i.e., to time division multiplexing of the TVG 378. Desirably, such multiplexing allows use of fewer amplifiers thereby resulting in a smaller more compact system 100.
  • the data acquisition CCA 316 samples the scattering signal to generate a plurality of complex samples.
  • the samples are provided to the DSP CCA 304.
  • the RX beamformer 346 simultaneously forms a plurality of beams in a horizontal plane based on complex samples.
  • the beams are formed with offset phase centers using, for example, linear combinations of the complex samples.
  • the number of beams is less than or equal to the number of receiving transducer elements.
  • each of the beams defines a fan or elliptically shaped beam.
  • the beams are formed in the horizontal plane while calculated angle of arrival processing is performed in the horizontal plane.
  • the horizontal plane is substantially orthogonal to a plane defined by a surface (or the bottom ocean, river, or seabed floor) of a body of water in which the beam is transmitted.
  • the beams are wider in the vertical dimension than in the horizontal dimension.
  • the DSP CCA 304 processes the plurality of complex samples to obtain image data comprising angles of arrival from M, M ⁇ N, scattering components in a vertical plane for each horizontal beam.
  • angle-of- arrival processing is applied to each horizontal beam in order to provide N/2 elevation angles and associated amplitudes at each range step in each beam.
  • angle of arrival processing is performed using a calculated angle of arrival method such as disclosed in U.S. Patent No. 6,130,641, entitled "Imaging Methods and Apparatus Using Model-Based Array Signal Processing, which is hereby incorporated by reference in its entirety.
  • the detection and output processing module 344 generates an image based on the image data in the vertical plane and data associated with the plurality of beams in the horizontal beam.
  • the detection and output processing module 344 may output, via the data interfaces 342 and 324, the image data in the vertical plane and data associated with the plurality of beams in the horizontal beam to allow an external processor to generate the image.
  • the sonar system 104 may be configured to scan by sequentially transmitting a pulse from each transducer of the transmit arrays 308.
  • the transmit arrays 308 includes three transducers, e.g., a transducer element at -15 degrees from a central transducer element, a third transducer element at +15 degrees from the central transducer element.
  • a pulse is transmitted sequentially each of the three transducers, e.g., the -15° transducer, the central transducer, and +15° transducer.
  • the processing described with reference to the method 600 may be repeated for each ping transmitted from each of the transducer of the transmit arrays 308.
  • a forward area e.g., from a UUV, may be scanned to, for example, provide obstacle avoidance ahead of the UUV.
  • Figures 7A-7D One such embodiment of the system was successfully operated in a lake and the results are shown in Figures 7A-7D.
  • the sonar was mounted on the end of a pole fixed to the side of the dock.
  • the sonar depth was approximately 3.5 m and various downward tilt angles and pointing directions were used.
  • Figure 7A shows a profile of the lakebed and surface buoy target.
  • the lakebed is relatively flat in this data set and the surface buoy is readily visible above the sonar.
  • Figure 7B shows a profile taken with the sonar pointed back towards the lake shore at an angle of -75 degrees. In this profile, the lakebed rises to the surface and a multipath image reflected by the surface is also visible.
  • Figure 7C shows a composite bathymetric map of the lakebed ahead of the sonar derived from the data of Figure 7B and the profiles of the other 17 beams that span the 45 degree field-of-view.
  • Figure 7D is a backscatter image for the same portion of the lakebed derived from the data from the same 18 beams as were used for Figure 1C.
  • one embodiment includes a sonar system and method that provides a compact and efficient forward looking sonar system for use in devices such as submersible vehicles or submarines.
  • applications of such a sonar system may include wide field-of-view, 3D detection and localization of underwater targets such as for mine counter measures, forward-looking 3d obstacle avoidance imaging, and/or forward looking 3D mapping of the seabed for hydrographic reconnaissance.
  • a software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
  • An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium.
  • the storage medium may be integral to the processor.
  • the processor and the storage medium may reside in an ASIC.
  • the ASIC may reside in a user terminal.
  • the processor and the storage medium may reside as discrete components in a user terminal.

Landscapes

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

Abstract

Selon certains modes de réalisation, la présente invention concerne un système et procédé pour sonar frontal, par exemple, configuré pour être utilisé dans un véhicule sous-marin. Un mode de réalisation comporte un procédé de formation d'images d'une région. Le procédé comprend la transmission d'au moins une impulsion acoustique depuis un transducteur et la réception d'une partie de l'impulsion à partir d'une région. Le procédé comprend également la génération d'un signal multivoie basé sur la partie reçue de l'impulsion diffusée à partir de la région, l'échantillonnage du signal diffusé pour générer une pluralité d'échantillons complexes, et la formation d'une pluralité de faisceaux dans un plan horizontal basés sur les échantillons complexes. La pluralité d'échantillons complexes peut être traitée pour obtenir une donnée d'image comportant des angles d'arrivée depuis des composantes de diffusion dans un plan vertical pour chaque faisceau horizontal. Une image peut être générée basée sur la donnée d'image. D'autres modes de réalisation comprennent des appareils, tels que des systèmes sonar.
PCT/US2007/078577 2006-09-15 2007-09-14 Système et procédé pour sonar frontal Ceased WO2008105932A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US84509406P 2006-09-15 2006-09-15
US60/845,094 2006-09-15

Publications (2)

Publication Number Publication Date
WO2008105932A2 true WO2008105932A2 (fr) 2008-09-04
WO2008105932A3 WO2008105932A3 (fr) 2008-10-30

Family

ID=39712366

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/078577 Ceased WO2008105932A2 (fr) 2006-09-15 2007-09-14 Système et procédé pour sonar frontal

Country Status (1)

Country Link
WO (1) WO2008105932A2 (fr)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8514658B2 (en) 2009-07-14 2013-08-20 Navico Holding As Downscan imaging sonar for reduced interference
US9142206B2 (en) 2011-07-14 2015-09-22 Navico Holding As System for interchangeable mounting options for a sonar transducer
US9182486B2 (en) 2011-12-07 2015-11-10 Navico Holding As Sonar rendering systems and associated methods
US9223022B2 (en) 2009-07-14 2015-12-29 Navico Holding As Linear and circular downscan imaging sonar
US9244168B2 (en) 2012-07-06 2016-01-26 Navico Holding As Sonar system using frequency bursts
US9268020B2 (en) 2012-02-10 2016-02-23 Navico Holding As Sonar assembly for reduced interference
EP3096159A1 (fr) * 2015-05-20 2016-11-23 Navico Holding AS Systèmes et procédés d'utilisation de sonar interférométrique et/ou la formation de faisceaux pour imagerie 3d
US9886938B2 (en) 2015-02-10 2018-02-06 Navico Holding As Transducer array having a transceiver
US10024957B2 (en) 2015-09-17 2018-07-17 Navico Holding As Adaptive beamformer for sonar imaging
EP3370081A1 (fr) * 2017-03-03 2018-09-05 BAE SYSTEMS plc Émetteur-récepteur numérique
WO2018158559A1 (fr) * 2017-03-03 2018-09-07 Bae Systems Plc Émetteur-récepteur
US10151829B2 (en) 2016-02-23 2018-12-11 Navico Holding As Systems and associated methods for producing sonar image overlay
CN111487628A (zh) * 2020-05-19 2020-08-04 中国科学院声学研究所 一种下视多波束合成孔径成像声纳“零度”干扰抑制方法
WO2021034366A1 (fr) * 2019-08-07 2021-02-25 Raytheon Company Procédés et systèmes pour déterminer une profondeur d'un objet
US11143758B2 (en) 2017-10-13 2021-10-12 Navico Holding As Sonar transducer performance optimization
US11367425B2 (en) 2017-09-21 2022-06-21 Navico Holding As Sonar transducer with multiple mounting options
CN116380079A (zh) * 2023-04-12 2023-07-04 东南大学 一种融合前视声呐与orb-slam3的水下slam方法
CN116908822A (zh) * 2023-06-20 2023-10-20 哈尔滨工程大学 一种多通道声呐发射机的测试信号采集装置及电路测试与实时分析系统

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5200931A (en) * 1991-06-18 1993-04-06 Alliant Techsystems Inc. Volumetric and terrain imaging sonar
US5808967A (en) * 1996-10-07 1998-09-15 Rowe-Deines Instruments Incorporated Two-dimensional array transducer and beamformer
US5812494A (en) * 1997-06-02 1998-09-22 The United States Of America As Represented By The Secretary Of The Navy Wide-angle, forward-looking bathymetric mapping
US6130641A (en) * 1998-09-04 2000-10-10 Simon Fraser University Imaging methods and apparatus using model-based array signal processing
JP4829487B2 (ja) * 2004-08-10 2011-12-07 古野電気株式会社 前方探知ソナー及び水中画像表示装置

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10024961B2 (en) 2009-07-14 2018-07-17 Navico Holding As Sonar imaging techniques for objects in an underwater environment
US8514658B2 (en) 2009-07-14 2013-08-20 Navico Holding As Downscan imaging sonar for reduced interference
US9223022B2 (en) 2009-07-14 2015-12-29 Navico Holding As Linear and circular downscan imaging sonar
US8605550B2 (en) 2009-07-14 2013-12-10 Navico Holding As Downscan imaging sonar
US9541643B2 (en) 2009-07-14 2017-01-10 Navico Holding As Downscan imaging sonar
US9142206B2 (en) 2011-07-14 2015-09-22 Navico Holding As System for interchangeable mounting options for a sonar transducer
US9182486B2 (en) 2011-12-07 2015-11-10 Navico Holding As Sonar rendering systems and associated methods
US10247823B2 (en) 2011-12-07 2019-04-02 Navico Holding As Sonar rendering systems and associated methods
US9268020B2 (en) 2012-02-10 2016-02-23 Navico Holding As Sonar assembly for reduced interference
US9244168B2 (en) 2012-07-06 2016-01-26 Navico Holding As Sonar system using frequency bursts
US9354312B2 (en) 2012-07-06 2016-05-31 Navico Holding As Sonar system using frequency bursts
US10319356B2 (en) 2015-02-10 2019-06-11 Navico Holding As Transducer array having a transceiver
US9886938B2 (en) 2015-02-10 2018-02-06 Navico Holding As Transducer array having a transceiver
AU2016203271B2 (en) * 2015-05-20 2017-11-02 Navico Holding As Sonar systems and methods using interferometry and/or beamforming for 3d imaging
EP3096159A1 (fr) * 2015-05-20 2016-11-23 Navico Holding AS Systèmes et procédés d'utilisation de sonar interférométrique et/ou la formation de faisceaux pour imagerie 3d
US10114119B2 (en) 2015-05-20 2018-10-30 Navico Holding As Sonar systems and methods using interferometry and/or beamforming for 3D imaging
US10024957B2 (en) 2015-09-17 2018-07-17 Navico Holding As Adaptive beamformer for sonar imaging
US10151829B2 (en) 2016-02-23 2018-12-11 Navico Holding As Systems and associated methods for producing sonar image overlay
EP3370081A1 (fr) * 2017-03-03 2018-09-05 BAE SYSTEMS plc Émetteur-récepteur numérique
WO2018158559A1 (fr) * 2017-03-03 2018-09-07 Bae Systems Plc Émetteur-récepteur
US11367425B2 (en) 2017-09-21 2022-06-21 Navico Holding As Sonar transducer with multiple mounting options
US11143758B2 (en) 2017-10-13 2021-10-12 Navico Holding As Sonar transducer performance optimization
WO2021034366A1 (fr) * 2019-08-07 2021-02-25 Raytheon Company Procédés et systèmes pour déterminer une profondeur d'un objet
US11724787B2 (en) 2019-08-07 2023-08-15 Raytheon Company Methods and systems for determining a depth of an object
CN111487628A (zh) * 2020-05-19 2020-08-04 中国科学院声学研究所 一种下视多波束合成孔径成像声纳“零度”干扰抑制方法
CN111487628B (zh) * 2020-05-19 2022-05-03 中国科学院声学研究所 一种下视多波束合成孔径成像声纳“零度”干扰抑制方法
CN116380079A (zh) * 2023-04-12 2023-07-04 东南大学 一种融合前视声呐与orb-slam3的水下slam方法
CN116908822A (zh) * 2023-06-20 2023-10-20 哈尔滨工程大学 一种多通道声呐发射机的测试信号采集装置及电路测试与实时分析系统

Also Published As

Publication number Publication date
WO2008105932A3 (fr) 2008-10-30

Similar Documents

Publication Publication Date Title
WO2008105932A2 (fr) Système et procédé pour sonar frontal
AU2020202507B2 (en) Aspects of sonar systems or other acoustic imaging systems
US12216206B2 (en) Sonar data compression
EP3449279B1 (fr) Système et procédé doppler acoustique
Bellettini et al. Design and experimental results of a 300-kHz synthetic aperture sonar optimized for shallow-water operations
US12306296B2 (en) Acoustic doppler system and method
WO2003009276A2 (fr) Systeme de formation de faisceaux de sonar
US11774587B2 (en) Multimission and multispectral sonar
Han et al. A real-time 3-D underwater acoustical imaging system
Cochrane et al. Quantification of a multibeam sonar for fisheries assessment applications
US20200333787A1 (en) Marine surface drone and method for characterising an underwater environment implemented by such a drone
Pinto et al. Real-and synthetic-array signal processing of buried targets
Liu et al. A low-complexity real-time 3-D sonar imaging system with a cross array
CN113108778B (zh) 一种具备多条带模式的深水多波束测深方法及系统
CN116500625B (zh) 恢复成像方法、装置、系统、电子设备及可读存储介质
Thompson et al. Two dimensional and three dimensional imaging results using blazed arrays
Santos et al. Source localization with vector sensor array during the Makai experiment
RU2802295C1 (ru) Впередсмотрящий гидролокатор с повышенным разрешением по дальности
JP2001174543A (ja) アクティブソーナー装置およびアクティブソーナー方法
US20250264608A1 (en) Acoustic doppler system and method
Xu et al. First results of a novel and low power forward looking sonar technology for small AUV's
Chiang et al. A low power imaging and obstacle avoidance sonar for small UUVs
Hagen et al. Robust synthetic aperture sonar operation for AUVs
Chiang et al. A portable, electronic-focusing sonar system for AUVs using 2D sparse-array technology
Watanabe et al. Study on improvement in resolution of synthetic aperture sonar using spatial filter

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: 07873735

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07873735

Country of ref document: EP

Kind code of ref document: A2