Patent Publication Number: US-11047964-B2

Title: Sonar transducer having geometric elements

Description:
FIELD OF THE INVENTION 
     Embodiments of the present invention relate generally to sonar transducer operation, and more particularly, to systems and apparatuses for sonar transducer operation utilizing geometric transducer elements. 
     BACKGROUND OF THE INVENTION 
     Sonar (SOund Navigation And Ranging) has long been used to detect waterborne or underwater objects. For example, sonar devices may be used to determine depth and bottom topography, detect fish, locate wreckage, etc. In this regard, due to the extreme limits to visibility underwater, sonar is typically the most accurate way to locate objects underwater. Sonar transducer elements, or simply transducers, convert electrical energy into sound or vibrations at a particular frequency. A sonar sound beam (e.g., one or more sonar signals) is transmitted into and through the water and is reflected from objects it encounters. The transducer receives the reflected sound (the “sonar returns”) and converts the sound energy into electrical energy. Based on the known speed of sound, it is possible to determine the distance to and/or location of the waterborne or underwater objects. The sonar return signals can also be processed to be displayed on a display device, giving the user a “picture” (or image) of the underwater environment. 
     The shape of the emitting face of a transducer element may dictate the beam shape of the sonar signals emitted into the underwater environment. For example, an elongated emitting face may generate a fan-shaped beam pattern and a transducer element with a square or circular shaped emitting face may have a more conical beam shape. Each beam shape is associated with distinct characteristics in sonar images resulting therefrom, such as the data resolution for underwater structures, fish, or other underwater objects. 
     BRIEF SUMMARY OF THE INVENTION 
     In some sonar transducer arrangements, a single transducer element may emit one or more sonar signals into the body of water. The resulting sonar returns are then received by one or more second receiving elements and/or the transmitting element. As mentioned above, the shape of the emitting face of the transducer element may determine the shape of the sonar beam emitted therefrom. In applications using an elongated (e.g., linear, elongated rectangle, or the like) transducer element produces a fan-shaped beam, the resulting sonar images may have high structural detail, but relatively low detail for moving objects including fish, bait, or the like. As the length of the emitting face with respect to the width becomes closer to a 1:1 ratio, the shape of the sonar beam shifts from being fan-shaped to a more cone-shape, resulting in reduced structural detail, but an increase in fish detail (e.g., producing desirable “fish arches”). As such, using a single transmitting crystal can limit the resulting image in desirability, such as by producing high structural detail with low fish detail, mediocre structural and fish detail, or high fish detail and low structural detail. 
     In an example embodiment, a sonar transducer is provided that includes two transmitting transducer elements and one receiving transducer element. The first transmitting transducer element is configured to provide high structural detail, while the second transmitting transducer element is configured to provide high fish detail. Particularly, the length-to-width ratio of the emitting face of the first transducer element is larger than the length-to-width ratio of the emitting face of the second transducer element. In some embodiments, to accommodate receiving sonar returns from both transmitting transducer elements, the transmitting transducer elements may emit at alternating times, different frequencies, or the like. 
     Since sonar returns are received with both high detail structural data and high detail fish data, sonar images may be generated with either the high detail structure data or the high detail fish data, which may be toggled as needed, shown together (such as in split screen), or blended to generate a new sonar image including both the high detail structural data and high detail fish data. In some embodiments, the blend ratio may be set at a predetermined optimal blend ratio. However, in some embodiments, the blend ratio may be dynamically adjusted by the user to render the desired level of detail based on application or user preference. 
     Sonar transducers are typically configured to be directional based, such as sidescan, forwardscan, downscan, or the like. As such, sonar transducers are generally housed in assemblies configured for the particular scan direction and mounting type. In this regard, in some embodiments, a transducer assembly may be provided with multi-directional scanning portions, such as including both forwardscan and downscan sonar transducer arrangements. By providing both forwardscan and downscan transducer arrangements in a common transducer assembly, the user may shift between forwardscan and downscan as desired, based on movement of a watercraft, operation of the trolling motor or engine, or the like. Additionally or alternatively, the sonar image data associated with the forwardscan may be merged with the downscan to provide a combined or continuous sonar image. In an example embodiment, the forwardscan portion may be curved to limit blind spots in the sonar image between the forwardscan portion of the sonar image and the downscan portion of the sonar image. 
     In an example embodiment, a system for imaging an underwater environment is provided including a transducer housing including a first transducer element configured to transmit one or more first sonar signals into a body of water and a second transducer element configured to transmit one or more second sonar signals into the body of water. A length-to-width ratio of an emitting face of the first transducer element is larger than a length-to-width ratio of an emitting face of the second transducer element. The transducer housing also includes a sonar signal processor and at least one third transducer element configured to receive one or more first sonar returns from the one or more first sonar signals and one or more second sonar returns from the one or more second sonar signals. The sonar signal processor is configured to receive the one or more first sonar returns, receive the one or more second sonar returns, and determine sonar image data based on both the one or more first sonar returns and the one or more second sonar returns. The sonar image data forms a sonar image representing the underwater environment. In an example embodiment, the marine electronic device also includes a user interface including a display, a marine electronic device processor, and a memory including computer program code. The computer program code is configured to, with the marine electronic device processor, cause the marine electronic device to receive the sonar image data from the sonar signal processor and cause presentation of the sonar image, based on the sonar image data. The sonar image includes a real time representation of the underwater environment. 
     In some example embodiments, the sonar signal processor and memory are further configured to determine a desired blend ratio of the first sonar return data and second sonar return data and determine the sonar image data by blending the first sonar return data and the second sonar return data based on the desired blend ratio. In an example embodiment, the emitting face of the first transducer element defines a rectangular shape of a first size and the emitting face of the second transducer element defines a rectangular shape of a second size. In some example embodiments, the emitting face of the first transducer element defines a rectangular shape and the emitting face of the second transducer element defines a circular shape. In an example embodiment, the second emitting face defines a second shape that is different than a first shape of the first emitting face. In some example embodiments, the first transducer element is configured to transmit the one or more first sonar signals in a fan-shaped sonar beam and the second transducer element is configured to transmit the one or more second sonar signals in a cone-shaped sonar beam. In an example embodiment, the first transducer element transmits the one or more first sonar signals during a first time period and the second transducer element transmits the one or more second sonar signals during a second time period. The first time period is separate from the second time period. In some example embodiments, the first transducer element transmits the one or more first sonar signals at a first frequency and the second transducer element transmits the one or more second sonar signals at a second frequency. The first frequency is different from the second frequency. In some example embodiments, the at least one third transducer element includes a plurality of transducer elements arranged in a linear array. 
     In a further example embodiment, a transducer assembly is provided including a transducer housing defining a forward scanning portion and a down scanning portion. The down scanning portion includes a first transducer element configured transmit one or more first sonar signals in a generally forward and downward direction into a body of water, a first transducer array configured to receive one or more first sonar returns from the one or more first sonar signals and including a first plurality of transducer elements arranged in a first linear array, and a second transducer array configured to receive one or more second sonar returns from the one or more first sonar signals and including a second plurality of transducer elements arranged in a second linear array. A longitudinal axis of the first linear array is perpendicular to a longitudinal axis of the second linear array. The down scanning portion includes a second transducer element configured to transmit one or more second sonar signals in a generally downward direction into the body of water; a third transducer array configured to receive one or more third sonar returns from the one or more second sonar signals and including a third plurality of transducer elements arranged in a third linear array; and a fourth transducer array configured to receive one or more fourth sonar returns from the one or more second sonar signals and including a fourth plurality of transducer elements arranged in a fourth linear array. A longitudinal axis of the third linear array is perpendicular to a longitudinal axis of the fourth linear array. 
     In an example embodiment, the forward scanning portion defines a curved surface extending from a forward end to a rear end, such that the surface at the rear end of the forward scanning portion is substantially in the horizontal plane that is parallel to a surface of the body of water. 
     An example embodiment of the present invention includes an example sonar transducer. The above referenced summary section is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section. The summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates an example vessel including various sonar transducer assemblies, in accordance with some embodiments discussed herein; 
         FIGS. 2A and 2B  illustrate example sonar transducer assemblies with poly-geometric transducer elements, in accordance with some embodiments discussed herein; 
         FIG. 3  illustrates example sonar beam shapes, in accordance with some embodiments discussed herein; 
         FIG. 4  illustrates an example transducer assembly including a forward scanning portion and a down scanning portion, in accordance with some embodiments discussed herein; 
         FIG. 5A  illustrates a cross-sectional view of the transducer assembly of  FIG. 4 , in accordance with some embodiments discussed herein; 
         FIG. 5B  illustrates a cross-sectional view of another example transducer assembly, in accordance with some embodiments discussed herein; 
         FIG. 6  illustrates a block diagram of an example marine electronic system, in accordance with some example embodiments discussed herein; and 
         FIG. 7  illustrates a flowchart of example methods of operating a sonar transducer assembly according to some embodiments discussed herein. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. 
     As depicted in  FIG. 1 , a watercraft, e.g. vessel  100 , configured to traverse a marine environment, e.g. body of water  101 , may use one or more sonar transducer assemblies  102   a ,  102   b , and  102   c  disposed on and/or proximate to the vessel. The vessel  100  may be a surface watercraft, a submersible watercraft, or any other implementation known to those skilled in the art. The transducer assemblies  102   a ,  102   b , and  102   c  may each include one or more transducer elements configured to transmit sound waves into a body of water, receive sonar return signals from the body of water, and convert the sonar return signals into sonar return data. 
     One or more sonar beams may be generated by the one or more transducer assemblies  102   a ,  102   b , and  102   c  when deployed in the body of water  101 . In some instances, a plurality of transducer elements may be embodied in a transducer assembly. In some instances, the transducer assembly may include one or more of a right scanning (e.g., sidescan) element, a left scanning (e.g., sidescan) element, a conical downscan sonar element, and/or a bar (e.g., linear, elongated rectangle, or the like) downscan sonar element, which may be housed within a transducer housing. In some example embodiments, the transducer assembly may be a transducer array, e.g. a “phased array.” The transducer array may include a plurality of transducer elements arranged on a printed circuit board (PCB). The PCB may mechanically support and electrically connect the electronic components, including the transducer elements using conductive tracks (e.g. traces), pads, and other features. The conductive tracks may comprise sets of traces, for example, each transducer elements may be mounted to the PCB such that the transducer element is in electrical communication with a set of traces. Each transducer element, sub-array, and/or the array of transducer elements may be configured to transmit one or more sonar pulses and/or receive one or more sonar return signals. 
     The transducer arrays or individual transducer elements may transmit one or more sonar signals, e.g. sonar beams, into a body of water with a transmit transducer, a transmit/receive transducer, or similar device. When the sound waves, of the sonar beams, strike anything of differing acoustic impedance (e.g., the sea floor or something suspended in the water above the bottom), the sound waves reflect off that object. These echoes (or sonar return signals) may strike the transmitting transducer element and/or a separate one or more sonar receiver elements, which convert the echoes back into an electrical signal which is processed by a processor (e.g., processing circuity  407  and/or a sonar signal processor  449  as discussed in reference to  FIG. 6 ) and sent to a display (e.g., an LCD) mounted in the cabin or other convenient location in the watercraft. This process is often called “sounding”. Since the speed of sound in water may be determined by the properties of the water (approximately 4800 feet per second in fresh water), the time lapse between the transmitted signal and the received echoes can be measured and the distance to the objects determined. This process may repeat itself many times per second. The results of many soundings are used to build a picture on the display of the underwater environment, e.g. a sonar image. 
     In an example embodiment, the one or more transducers assemblies may include multiple transducer arrays and/or transducer elements cooperating to receive sonar return signals from the underwater environment. The transducer arrays and/or transducer elements may be arranged in a predetermined configuration, e.g. relative positions, including known distances between each transducer array or transducer element. The relative positions and known distances between the transducer array or transducer element may be used to resolve an angle associated with the sonar returns (and, for example, a corresponding object in the underwater environment). The respective angles determined by the relative positions and known distances of the transducer arrays or transducer elements may be compared and combined to generate a two-dimensional and/or a three-dimensional position of the sonar return signals (and, for example, a corresponding object in the underwater environment). 
     In some example embodiments, the returns from a plurality of the transducer arrays and/or transducer elements may be compared via the process of interferometry to generate one or more angle values. Interferometry may involve determining the angle to a given sonar return signal via a phase difference between the returns received at two or more transducer arrays and/or transducer elements. In some embodiments, the process of beamforming may be used in conjunction with the plurality of transducer arrays and/or transducer elements to generate one or more angle values associated with each sonar return signal. Beamforming may involve generating a plurality of receive-beams at predetermined angles by spatially defining the beams based on the relative phasing of the sonar returns and detecting the distance of the sonar returns in each respective beam. Beamforming and interferometry are further described in U.S. patent application Ser. No. 14/717,458, entitled “Sonar Systems using Interferometry and/or Beamforming for 3D Imaging”, published as US 2016/0341827, and U.S. Pat. No. 9,739,884, entitled Systems and Associated Methods for Producing a 3D Sonar Image,” both of which are assigned to the Assignee of the present application and are hereby incorporated by reference herein in their entireties. 
     In an example embodiment, a vessel  100  may include a main propulsion motor  105 , such as an outboard or inboard motor. Additionally, the vessel  100  may include trolling motor  108  configured to propel the vessel  100  or maintain a position. The one or more transducer assemblies (e.g.,  102   a ,  102   b , and/or  102   c ) may be mounted in various positions and to various portions of the vessel  100  and/or equipment associated with the vessel  100 . For example, the transducer assemblies may be mounted to the transom  106  of the vessel  100 , such as depicted by transducer assembly  102   a , may be mounted to the bottom or side of the hull  104  of the vessel  100 , such as depicted by transducer assembly  102   b , or may be mounted to the trolling motor  108 , such as depicted by transducer assembly  102   c.    
     Example Transducer Assemblies 
       FIGS. 2A, 2B, 4, 5A, and 5B  illustrate some example embodiments of transducer assemblies and transducer element arrangements therein.  FIGS. 2A and 2B  depict a transducer assembly including a transducer housing  200  having a poly-geometric transducer element arrangement. The transducer housing may include a first emitting transducer element  202  and a second emitting transducer element ( 204  in  FIG. 2A or 205  in  FIG. 2B ). Each of the emitting transducer elements  202 ,  204 ,  205  may be configured to transmit one or more sonar signals into the underwater environment via at least one emitting face of each of the emitting transducer elements  202 ,  204 ,  205 . The shape of the emitting face of the emitting transducer element  202 ,  204 ,  205  may shape the sonar beam emitted therefrom. 
     In the examples depicted in  FIGS. 2A and 2B , the first emitting transducer element  202  has an emitting face in the shape of with an elongated rectangle. As used herein “elongated” should be interpreted as having a length (L) that is substantially longer that the width (W). The first emitting transducer element  202 , being a piezoelectric crystalline structure, may emit the first sonar signals into the body of water by converting electrical energy into vibrational energy, which is thereby transferred into the water surrounding the transducer assembly. As the vibrations travel away from the emitting face of the first emitting transducer element  202  a fan-shaped sonar beam  220 , such as depicted in  FIG. 3 , may be formed (e.g., at −3 dB). The fan-shaped beam  220  may produce sonar returns with high structure detail and relatively low fish detail when rendered in a sonar image, which may be due to the relatively wide section and the relatively narrow section of the fan-shaped beam. 
     Turning to the second emitting transducer elements  204  and  205  depicted in  FIGS. 2A and 2B , respectively, the second emitting transducer element  204  is a substantially cubic rectangular prism with a substantially square emitting face and the second emitting transducer element  205  is substantially a cylinder with a substantially circular emitting face. As the vibrations of the sonar signal travel away from the emitting face, a cone-shaped beam  230 , such as depicted in  FIG. 3 , may be formed (e.g., at −3 dB). The conical beam  230  may produce sonar returns with high fish detail and relatively low structural detail when rendered in a sonar image, which may be due to the relatively wide beam shape. 
     Although an elongated rectangular emitting face and a circle or square emitting face are depicted, any emitting face shape may be substituted. The level of detail for both fish and structure may shift respectively as the shape of the resultant beam transitions between the fan shape and the conical shape. In some example embodiments a first length-to-width ratio (L 1 /W 1 ) of the first emitting transducer element  202  may be larger than a second length-to-width ratio (L 2 /W 2 ) of the second emitting transducer element  204 ,  205 , such that each has a differently shaped beam and therefore different resultant sonar image characteristics. 
     The transducer housing  200  may also include one or more receiving transducer elements  206 . The receiving transducer elements  206  may be configured to receive sonar returns from the first sonar signals emitted from the first emitting transducer element  202  and the second emitting transducer element  204 ,  205 . In some embodiments, to facilitate receiving sonar returns from both the first emitting transducer element  202  and the second emitting transducer element  204 ,  205  without some interference, the first and second emitting transducer elements may be configured to transmit during distinct, e.g. separate, time periods. For example, the first emitting transducer element  202  and the second emitting transducer element  204 ,  205  may alternately transmit, such that only the first or the second emitting transducer element is transmitting at any one time. 
     Additionally or alternatively, the first emitting transducer element  202  and the second emitting transducer element  204 ,  205  may be configured to transmit at different frequencies. For example the first emitting transducer element  202  may be configured to transmit at a first frequency and the second emitting transducer element  204 ,  205  may be configured to transmit at a second frequency, which is different than the first frequency. The first frequency may be a bandwidth that is sufficiently different from a bandwidth of the second frequency to prevent interface from the other of the emitting transducer elements. 
     In some example embodiments, the receiving transducer element  206  may be a single transducer element, e.g. piezoelectric crystalline structure, configured to convert the vibrations of the sonar returns into an electrical signal for processing by a sonar signal processor, as discussed below. In an example embodiment, the receiving transducer element  206  may be a transducer array including a plurality of individual transducer elements  208  arranged in a linear array. In some example embodiments, the receiving transducer element  206  may include a plurality of individual transducer elements  208  arranged in a first linear array and a second linear array, similar to the receiving transducers  314 A and  314 B depicted in  FIG. 4 . In some embodiments, the longitudinal axis of the first linear array may be perpendicular to longitudinal axis of the second linear array. 
     Referring to  FIG. 6 , a sonar signal processor  449  may receive, via the receiving transducer  206 , one or more sonar returns from the sonar signals transmitted by the first emitting transducer element  202  and one or more second sonar returns from the sonar signals transmitted by the second emitting transducer element  204 ,  205 . In an example embodiment, the sonar signal processor  449  may receive the sonar return data from the receiving transducer element  206  as a data stream or feed, such as in an instance in which the receiving transducer element is a single transducer element. In some example embodiments, the sonar return data may be multiplexed or otherwise addressed by the sonar signal processor  449 , such that the sonar returns are identifiably received from the first linear array, the second linear array, and/or individual transducer elements  208 . 
     The sonar signal processor  449  may be configured to generate sonar image data from both the first sonar returns and second sonar returns. The sonar image data may form a sonar image representing the underwater environment, including without limitation 2D sonar images, 3D sonar images, such as based on interferometry of the sonar image data corresponding to the first emitting transducer element  202  and the second emitting transducer element  204 ,  205 , and/or live 2D or 3D sonar images of the underwater environment. 
     In an example embodiment, the processing circuitry  407  may be configured to cause one or more sonar images to render (e.g., present) on the display  440 . In some example embodiments, the processing circuitry  407  may determine which sonar images to display based on user input on a user interface  435 . The determined sonar image for display may be a sonar image based on the first sonar return, a sonar image based on the second sonar image, or a blended sonar image based on the sonar data associated with both the first sonar return and the second sonar return. 
     In an example embodiment, the blended sonar image may include sonar image data from both the first sonar return and the second sonar return. In some embodiments, the processing circuitry  407  renders the sonar image data for both sonar returns together to generate the blended image without further processing. In some example embodiments, the processing circuitry  407  may determine a desired blend ratio and generate the blended sonar image based on the blend ratio. The blend ratio may be automatically determined, such as a preprogramed blend ratio or may be based on a user input on the user interface. 
     The processing circuitry  407  may utilize brightness, transparency, or other suitable image overlay contrasting. For example, the processing circuitry  407  may generate a blended sonar image with a 50/50 contrast, such that the sonar image data from each of the first and second sonar returns is given equal weight. The processing circuitry  407  may generate further blended sonar images at different contrast levels based on a user input, such as increasing the weight of the second sonar image data associated with the second emitting transducer element  204 ,  205  when attempting to locate fish. In another example, the user input may cause an increase to the weight of the first sonar image data associated with the first emitting sonar transducer  202  when attempting to move the vessel to a new location on the body of water, such when structural information is important for safety and/or determining a quality fishing location. 
     Additionally or alternatively, the processing circuitry  407  may be configured to receive propulsion information from a propulsion system  409 , such as operating conditions of the main propulsion engine  105  and/or trolling motor  108 . The processing circuitry  407  may determine a blend ratio with a higher weight for the second sonar image data associated with the second emitting transducer element  204 ,  205  when the propulsion information indicates that the vessel  100  is stationary, below a predetermined movement threshold, such as 2 knots, and/or the main propulsion engine  105  and/or trolling motor are not operating. Similarly, the processing circuitry  407  may determine a blend ratio with a higher weight for the first sonar image data associated with the first emitting transducer element  202  when the propulsion information indicates that the vessel  100  is moving greater than a predetermined movement threshold, such as 2 knots, and/or the main propulsion engine  105  and/or trolling motor are operating. 
     The above described transducer assembly  200  may enable rendering of sonar images including either, or both, the high structural detail and the high fish detail. Additionally, since sonar return data is transmitted by two separate emitting transducer elements and received by a common receiving transducer element  206 , the sonar images may be live, e.g., real time or near real time, 2D or 3D sonar images of underwater environment. 
       FIG. 4  illustrates a transducer assembly having a transducer housing  300  including a forward scanning portion  302  and down scanning portion  304 . The forward scanning portion  302  may include an emitting element  306  and one or more receiving arrays  308 A,  308 B. The emitting element  306  may be configured to transmit one or more first sonar signals into the body of water, such as in a manner similar to the emitting transducer elements discussed above. Although, only a single emitting transducer element  306  is depicted, a transducer element configuration similar to the transducer assembly illustrated in  FIG. 2A or 2B  may substituted for additional functionality. 
     Each receiving array  308 A,  308 B may include a plurality of individual transducer elements  310 , e.g. piezoelectric crystalline structures, arranged in a linear array. In some embodiments, the individual transducer elements  310  may be arranged in a first linear array  308 A and a second linear array  308 B. A longitudinal axis of the first linear array  308 A may be perpendicular to a longitudinal axis of the second linear array  308 B. Similar to the operation of the receiving element  206  discussed above in reference to  FIGS. 2A and 2B , the individual transducer elements  310  may convert the vibrational energy of reflected sonar signals, e.g. sonar returns, into an electrical signal. The sonar signal processor  449  ( FIG. 6 ) may receive one or more sonar returns from the receiving transducer arrays  308 A,  308 B. In an example embodiment, the sonar signal processor  449  may receive the sonar return data from the receiving transducer arrays  308 A,  308 B as a data stream or feed. In some example embodiments, the sonar return data may be multiplexed or otherwise addressed by the sonar signal processor  449 , such that the sonar returns are identifiably received from the first linear array  308 A, the second linear array  308 B, and/or individual transducer elements  310 . 
     The down scanning portion  304  may include an emitting transducer element  312  and one or more receiving transducer arrays  314 A,  314 B. In some example embodiments, the down scanning portion  304  may also include a second emitting element  316 , which may have a different emitting face shape, such as an elongated rectangular emitting face. The emitting transducer element  312  and/or  316  may be configured and operate with the receiving transducer array(s)  314 A,  314 B in a manner similar to the transducer assemblies discussed in  FIGS. 2A and 2B  and/or the down transducer assembly of the down scanning portion  302  discussed above. 
       FIGS. 5A and 5B  illustrate cross-sectional views of example transducer assemblies, such as the transducer assembly of  FIG. 4 , in accordance with some embodiments. The transducer housing  300  may be configured to retain the forward scanning portion  302  and the down scanning portion  304 . When the transducer housing  300  is mounted to a vessel  100 , the down scanning portion  304  may face substantially downward into the body of water  101  in a horizontal plane parallel to the surface of the body of water, such that the downward scanning portion  304  transmits one or more sonar signals in a generally downward direction. The forward scanning portion  302  may face at least partially forward and angle out of the horizontal plane by a predetermined amount or angle, such as 30 degrees, 45 degrees, or other suitable angle, such that the forward scanning portion  302  transmits sonar signals into the body of water in a generally forward and downward direction. 
     In some instances, a blind spot  318  may be created by the difference in transmission and receiving angles of the forward scanning portion  302  and down scanning portion  304 , as shown in  FIG. 5A . The blind spot  318  may be mitigated or eliminated by reduction of the angle difference between the forward scanning portion  302  and the down scanning portion  304 . Additionally or alternatively, the forward scanning portion  302 ′ may be curved, as depicted in  FIG. 5B , to mitigate or eliminate the blind spot  318 . In an example embodiment, the forward scanning portion  302 ′ is curved from a forward end to an aft end, such that the aft end of the forward scanning portion is substantially in the horizontal plane. 
     Referring also to  FIG. 6 . the sonar signal processor  449  may be configured to generate sonar image data based on each of sonar returns received from both the receiving transducer array(s)  308 A,  308 B of the forward scanning portion  302  and the receiving transducer array(s)  314 A,  314 B of the down scanning portion  304 . The processing circuitry  407  may receive the sonar image data from the sonar signal processor  449  and cause one or more sonar images to be presented on a user interface. The sonar images may be 2D sonar images, 3D sonar images, blended sonar images, or the like based on the sonar returns from the forward scanning portion  302  and/or the down scanning portion  304 . 
     In some example embodiments, the sonar signal processor  449  and/or the processing circuitry  407  may generate a continuous sonar image based on both the sonar returns from the forward scanning portion  302  and the down scanning portion  304 . In one such embodiment, the sonar signal processor  449  and/or the processing circuitry  407  may register the common edge of the sonar image based on the sonar return from the forward scanning portion  302  and the sonar image based on the sonar return from the down scanning portion  304 . The sonar signal processor and/or the processing circuitry  407  may then stitch the common edges of the sonar images together based on the registration. 
     As discussed above the one or more generated sonar images may be rendered on the display  440 . The processing circuitry  407  may automatically determine the sonar image to display, such as due to operational conditions, discussed below, or preprogrammed default selection. Additionally or alternatively, the processing circuitry  407  may determine the sonar image to render on the display based on user input on the user interface  435 . 
     In an example embodiment, the processing circuitry  407  may be configured to render one or more sonar images based on the operational condition of the vessel, which may be based on propulsion information received from the propulsion system  409 . For example, the processing circuitry  407  may render a downscan sonar image in an instance in which the vessel  100  is stationary or moving less than a predetermined threshold, such as 2 knots, or the main propulsion engine  105  and/or the trolling motor  108  is not operating. The processing circuitry  407  may render a forwardscan sonar image in an instance in which the vessel  100  is moving greater than a predetermined threshold, such as 2 knots, or the main propulsion engine  105  and/or the trolling motor  108  is operating. Additionally or alternatively, the processing circuitry  407  may pan a continuous sonar image based on the operational condition of the propulsion system  409 . For example, the processing circuitry  407  may pan the continuous sonar image toward the downscan portion of the image when the propulsion information indicates the vessel  100  is relatively stationary and toward the forwardscan portion when the propulsion information indicates movement of the vessel  100 . 
     Example Architecture 
       FIG. 6  shows a block diagram of computing device, such as user device  403 . The depicted computing device is an example marine electronic device  405 . The marine electronic device  405  may include a number of different modules or components, each of which may comprise any device or means embodied in either hardware, software, or a combination of hardware and software configured to perform one or more corresponding functions. The marine electronic device may also be in communication with a network  402 . 
     The marine electronic device  405  may also include one or more communications modules configured to communicate with one another in any of a number of different manners including, for example, via a network. In this regard, the communications module may include any of a number of different communication backbones or frameworks including, for example, Ethernet, the NMEA  2000  framework, GPS, cellular, Wi-Fi, or other suitable networks. The network may also support other data sources, including GPS, autopilot, engine data, compass, radar, etc. Numerous other peripheral devices such as one or more wired or wireless multi-function displays may be included in a marine system  400 . 
     The marine electronic device  405  may include a processor  410 , a memory  420 , a user interface  435 , a display  440 , one or more sensors (e.g. position sensor  445 , other sensors  447 , etc.), and a communication interface  430 . 
     The processor  410  may be any means configured to execute various programmed operations or instructions stored in a memory device such as a device or circuitry operating in accordance with software or otherwise embodied in hardware or a combination of hardware and software (e.g. a processor operating under software control or the processor embodied as an application specific integrated circuit (ASIC) or field programmable gate array (FPGA) specifically configured to perform the operations described herein, or a combination thereof) thereby configuring the device or circuitry to perform the corresponding functions of the processor  410  as described herein. In this regard, the processor  410  may be configured to analyze electrical signals communicated thereto to provide or receive sonar data, sensor data, location data, and/or additional environmental data. For example, the processor  410  may be configured to receive sonar return data, generate sonar image data, and generate one or more sonar images based on the sonar image data. 
     In some embodiments, the processor  410  may be further configured to implement signal processing or enhancement features to improve the display characteristics or data or images, collect or process additional data, such as time, temperature, GPS information, waypoint designations, or others, or may filter extraneous data to better analyze the collected data. It may further implement notices and alarms, such as those determined or adjusted by a user, to reflect depth, presence of fish, proximity of other vehicles, e.g. watercraft, etc. 
     In an example embodiment, the memory  420  may include one or more non-transitory storage or memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable. The memory  420  may be configured to store instructions, computer program code, marine data, such as sonar data, chart data, location/position data, and other data associated with the navigation system in a non-transitory computer readable medium for use, such as by the processor for enabling the marine electronic device  405  to carry out various functions in accordance with example embodiments of the present invention. For example, the memory  420  could be configured to buffer input data for processing by the processor  410 . Additionally or alternatively, the memory  420  could be configured to store instructions for execution by the processor  410 . 
     The communication interface  430  may be configured to enable connection to external systems (e.g. an external network  402 ). In this manner, the marine electronic device  405  may retrieve stored data from a remote server  460  via the external network  402  in addition to or as an alternative to the onboard memory  420 . Additionally or alternatively, the marine electronic device may transmit or receive data, such as sonar signals, sonar returns, sonar image data or the like to or from a transducer assembly  407 , more particularly to or from a sonar signal processor  449 . In some embodiments, the marine electronic device may also be configured to communicate with a propulsion system  409  of the vessel  100 . The marine electronic device may receive data indicative of operation of the propulsion system, such as engine or trolling motor running, running speed, or the like. 
     The position sensor  445  may be configured to determine the current position and/or location of the marine electronic device  405 . For example, the position sensor  445  may comprise a GPS, bottom contour, inertial navigation system, such as machined electromagnetic sensor (MEMS), a ring laser gyroscope, or other location detection system. 
     The display  440 , e.g. screen, may be configured to display images and may include or otherwise be in communication with a user interface  435  configured to receive input from a user. The display  440  may be, for example, a conventional LCD (liquid crystal display), a touch screen display, mobile device, or any other suitable display known in the art upon which images may be displayed. 
     In any of the embodiments, the display  440  may present one or more sets of marine data (or images generated from the one or more sets of data). Such marine data includes chart data, radar data, weather data, location data, position data, orientation data, sonar data, or any other type of information relevant to the watercraft. In some embodiments, the display  440  may be configured to present such marine data simultaneously as one or more layers or in split-screen mode. In some embodiments, a user may select any of the possible combinations of the marine data for display. 
     In some further embodiments, various sets of data, referred to above, may be superimposed or overlaid onto one another. For example, a route may be applied to (or overlaid onto) a chart (e.g. a map or navigational chart). Additionally or alternatively, depth information, weather information, radar information, sonar information, or any other navigation system inputs may be applied to one another. 
     The user interface  435  may include, for example, a keyboard, keypad, function keys, mouse, scrolling device, input/output ports, touch screen, or any other mechanism by which a user may interface with the system. 
     Although the display  440  of  FIG. 6  is shown as being directly connected to the processor  410  and within the marine electronic device  405 , the display  440  could alternatively be remote from the processor  410  and/or marine electronic device  405 . Likewise, in some embodiments, the position sensor  445  and/or user interface  435  could be remote from the marine electronic device  405 . 
     The marine electronic device  405  may include one or more other sensors  447  configured to measure environmental conditions. The other sensors  447  may include, for example, an air temperature sensor, a water temperature sensor, a current sensor, a light sensor, a wind sensor, a speed sensor, or the like. 
     The transducer assembly  102  may have one or more transducers (e.g., transducers  448 ,  449 ), such as a plurality of scanning portions  302 ,  304  (such as discussed in reference to  FIGS. 4-5B ) and/or various emitting or receiving transducers (such as discussed in reference to  FIGS. 2A-2B ). The transducer assembly  102  may also include a sonar signal processor  449  configured to receive one or more sonar returns and determine sonar image data. Although depicted in the transducer assembly  102 , it would be immediately understood by one of ordinary skill in the art, that the sonar signal processor  449  may be a portion of the user device  403 , the marine electronic device, the processing circuitry  407 , the processor  410 , or another remote device/system. 
     The propulsion system  409  may include the main propulsion motor  105  and/or trolling motor  108 . The propulsion motor  105  and/or the trolling motor  108  may include one or more sensors to measure operation or speed of main propulsion motor  105  and/or the trolling motor  108 . 
     Example Flowchart(s) and Operations 
     Embodiments of the present invention provide methods, apparatus and computer program products for operating a transducer assembly. Various examples of the operations performed in accordance with embodiments of the present invention will now be provided with reference to  FIG. 7 . 
       FIG. 7  illustrates a flowchart according to example methods for operating a sonar transducer according to an example embodiment. The operations illustrated in and described with respect to  FIG. 7  may, for example, be performed by, with the assistance of, and/or under the control of one or more of the processor  410 , memory  420 , communication interface  430 , user interface  435 , position sensor  445 , other sensor  447 , transducer assembly  102 , sonar signal processor  449 , display  440 , and/or propulsion system  409 . The method may include receiving first sonar return data from one or more first sonar signals at operation  502 , receiving second sonar return data from one or more second sonar signals at operation  504 , and determining sonar image data based on both the first sonar return data and the second sonar return data at operation  508 . 
     In some embodiments, the method may include additional, optional operations, and/or the operations described above may be modified or augmented. Some examples of modifications, optional operations, and augmentations are described below, as indicated by dashed lines, such as, determining a desired blend ratio at operation  506  and causing presentation of the sonar image on a user interface at operation  510 . 
       FIG. 7  illustrates a flowchart of a system, method, and computer program product according to an example embodiment. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware and/or a computer program product comprising one or more computer-readable mediums having computer readable program instructions stored thereon. For example, one or more of the procedures described herein may be embodied by computer program instructions of a computer program product. In this regard, the computer program product(s) which embody the procedures described herein may be stored by, for example, the memory  420  and executed by, for example, the processor  410 . As will be appreciated, any such computer program product may be loaded onto a computer or other programmable apparatus (for example, a marine electronic device  405 ) to produce a machine, such that the computer program product including the instructions which execute on the computer or other programmable apparatus creates means for implementing the functions specified in the flowchart block(s). Further, the computer program product may comprise one or more non-transitory computer-readable mediums on which the computer program instructions may be stored such that the one or more computer-readable memories can direct a computer or other programmable device (for example, a marine electronic device  405 ) to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus implement the functions specified in the flowchart block(s). 
     Conclusion 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the embodiments of the invention are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the invention. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the invention. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated within the scope of the invention. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.