Patent Description:
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.

<CIT> discloses a generic state of the art sonar transducer.

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 <NUM>:<NUM> 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 not covered by the claims, 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 examples, 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, 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 examples not covered by the claims, a transducer assembly may be provided with multidirectional 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, 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.

According to the invention, an array of receive transducer elements is used to form traditional sonar images, such as one-dimensional (1D) (e.g., time-based) sonar images. A sonar signal processor is configured to sum the sonar return data received from one or more individual receive transducer elements of the receive array. In this regard, depending on which receive transducer elements are utilized, different levels of definition of the resulting sonar image can be obtained. For example, in the situation where the array includes a large ratio of length to width (e.g., <NUM>:<NUM>), then summing the sonar return data from all or most of the individual receive transducer elements results in a 1D sonar image with relatively high-definition (e.g., which may be equivalent to a sonar image formed using a linear (e.g., rectangular-shaped) transducer element). Along similar lines, summing the sonar return data from a small subgroup of individual receive transducer elements (e.g., <NUM>-<NUM> elements) results in a 1D sonar image with relatively lower definition (e.g., which may be equivalent to a sonar image formed using a conical (e.g., circular-shaped) transducer element). Variations of summed sonar return data and relative positioning of the selected receive transducer elements to product different sonar images are, thus, contemplated.

According to the invention, an array of series-connected transmit transducer elements are used to form sonar signal within the water. In this regard, the "effective" emitting face of an array of transducer elements electrically connected in series can determine the resulting beam shape - thereby enabling different types of beam coverage depending on the shapes of the transducer elements and mounting configurations. According to the invention, the orientation of the emitting faces of each element in the array varies slightly to mimic a curved surface, which may provide for increased beam coverage. In this regard, in some embodiments, the effective curved surface for the emitting face of the array causes a widened beam coverage in the corresponding direction of the resultant beam - which may be desirable.

According to the invention, a system for imaging an underwater environment of a body of water comprising the features recited in independent claim <NUM> is provided. Preferred features of the system according to the invention are defined in the dependent claims numbered <NUM> to <NUM>.

According to the invention, there is also provided a method of operating a transducer assembly according to the subject matter of independent claim <NUM>.

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.

As depicted in <FIG>, a watercraft, e.g. vessel <NUM>, configured to traverse a marine environment, e.g. body of water <NUM>, may use one or more sonar transducer assemblies 102a, 102b, and 102c disposed on and/or proximate to the vessel. The vessel <NUM> may be a surface watercraft, a submersible watercraft, or any other implementation known to those skilled in the art. The transducer assemblies 102a, 102b, and 102c 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 102a, 102b, and 102c when deployed in the body of water <NUM>. 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 or include 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 <NUM> and/or a sonar signal processor <NUM> as discussed in reference to <FIG>) 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 <NUM> 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 <CIT>, entitled "Sonar Systems using Interferometry and/or Beamforming for 3D Imaging", published as <CIT>, and <CIT>, entitled Systems and Associated Methods for Producing a 3D Sonar Image," both of which are assigned to the Assignee of the present.

In an example embodiment, a vessel <NUM> may include a main propulsion motor <NUM>, such as an outboard or inboard motor. Additionally, the vessel <NUM> may include trolling motor <NUM> configured to propel the vessel <NUM> or maintain a position. The one or more transducer assemblies (e.g., 102a, 102b, and/or 102c) may be mounted in various positions and to various portions of the vessel <NUM> and/or equipment associated with the vessel <NUM>. For example, the transducer assemblies may be mounted to the transom <NUM> of the vessel <NUM>, such as depicted by transducer assembly 102a, may be mounted to the bottom or side of the hull <NUM> of the vessel <NUM>, such as depicted by transducer assembly 102b, or may be mounted to the trolling motor <NUM>, such as depicted by transducer assembly 102c.

<FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> illustrate some example embodiments of transducer assemblies and transducer element arrangements therein.

<FIG> and <FIG> depict a transducer assembly including a transducer housing <NUM> having a poly-geometric transducer element arrangement. The transducer housing may include a first emitting transducer element <NUM> and a second emitting transducer element (<NUM> in <FIG> or <NUM> in <FIG>). Each of the emitting transducer elements <NUM>, <NUM>, <NUM> 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 <NUM>, <NUM>, <NUM>. The shape of the emitting face of the emitting transducer element <NUM>, <NUM>, <NUM> may shape the sonar beam emitted therefrom.

In the examples depicted in <FIG> and <FIG>, the first emitting transducer element <NUM> 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 <NUM>, 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 <NUM> a fan-shaped sonar beam <NUM>, such as depicted in <FIG>, may be formed (e.g., at -<NUM> dB). The fan-shaped beam <NUM> 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 <NUM> and <NUM> depicted in <FIG> and <FIG>, respectively, the second emitting transducer element <NUM> is a substantially cubic rectangular prism with a substantially square emitting face and the second emitting transducer element <NUM> 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 <NUM>, such as depicted in <FIG>, may be formed (e.g., at -<NUM> dB). The conical beam <NUM> 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 (L1/W1) of the first emitting transducer element <NUM> may be larger than a second length-to-width ratio (L2/W2) of the second emitting transducer element <NUM>, <NUM>, such that each has a differently shaped beam and therefore different resultant sonar image characteristics.

<FIG> illustrates a transducer assembly according to the invention that includes an array of transmit transducer elements <NUM> instead of the transmit transducer elements <NUM>, <NUM>, <NUM> shown in <FIG> and <FIG>. Notably, in some embodiments, an array of transmit transducer elements (e.g., <NUM>) may be included along with other transmit transducer elements, such as the transmit transducer elements shown in <FIG> and <FIG>.

According to the invention, the array of transmit transducer elements <NUM> is made up of a plurality of transmit transducer elements <NUM> that are electrically connected in series to transmit sonar signals within a beam pattern (e.g., beam shape). In the depicted embodiment, the array is formed of three transducer elements 209a, 209b, and 209c that each have a length that is greater than their width (although other shapes of the elements and number of elements are contemplated). Further, the lengths of the elements are arranged in a line (e.g., end-to-end or near end-to-end) with respect to the horizontal plane (e.g., from the plan perspective shown in <FIG>). In this manner, the resultant beam may be wide in the perpendicular direction (e.g., along the line PCenterline or in the front-to-back direction of the watercraft - although other mounting orientations are contemplated).

Additionally, according to the invention, the emitting faces of each of the transducer elements 209a, 209b, 209c are oriented differently with respect to the surface of the water such that the "effective" emitting face of the array mimics a convex curved surface - thereby resulting in a wide beam coverage in the other direction (e.g., perpendicular to the line PCenterline or in the port-to-starboard direction of the watercraft). Thus, a resulting beam may be relatively wide in both directions. For example, some example beam shapes provide a <NUM> degree by <NUM> degree beam shape (e.g., at -<NUM> dB), although other example beam shapes are contemplated, such as a ~<NUM>-<NUM> degree by ~<NUM>-<NUM> degree beam shape.

<FIG> illustrates a cross-sectional view of an array of emitting transducer elements <NUM> according to the invention. In the depicted embodiment, the array <NUM> includes a center transmit transducer element 209b, a left transmit transducer element 209a, and a right transmit transducer element 209c. The center transmit transducer element 209b is mounted in the center of the array <NUM> and includes an emitting face 212b that is oriented in a first direction 211b and generally at a first angle βb with respect to a mounting plane PMounting (which may correspond to a theoretical waterline if the array <NUM> is mounted so as to be oriented generally downward). The left transmit transducer element 209a is mounted to the left of the center transmit transducer element 209b and includes an emitting face 212a that is oriented in a second direction 211a and generally at a second angle βa with respect to the mounting plane PMounting. The right transmit transducer element 209c is mounted to the right of the center transmit transducer element 209b and includes an emitting face 212c that is oriented in a third direction 211c and generally at a third angle βc with respect to the mounting plane PMounting. Thus, the second angle βa (corresponding to the left transmit transducer element) and the third angle βc (corresponding to the right transmit transducer element) are less than the first angle βb (corresponding to the center transmit transducer element). In this regard, there is an angle difference θa between the second angle βa and the first angle βb and an angle difference θb between the third angle βc and the first angle βb. In some embodiments, the angle differences may be the same such that the orientation of the emitting faces of the left and right transmit transducer elements are symmetrical with respect to the center transmit transducer element. For example, the angle difference θa, θb may be between <NUM> degrees and <NUM> degrees, such as <NUM> degrees. According to the invention, the resulting array <NUM> includes emitting faces of the transmit transducer elements that form effectively a curved surface (e.g., since the elements are connected in series and are configured to transmit together). As noted herein, having an effective curved surface results in a wider beam in the plane corresponding to the curved surface.

Example beam patterns <NUM>, <NUM>' that may result from such an example array are shown in <FIG> and <FIG> depending on the orientation and mounting position of the transducer housing <NUM>. For example, <FIG> illustrates a resulting beam pattern <NUM> with the transducer housing mounted facing generally downwardly, whereas <FIG> illustrates a resulting beam pattern <NUM>' with the transducer housing mounted facing forward of the watercraft <NUM>.

Notably, since the invention utilizes such an example array of transmit transducer elements, such a structured array may provide a beneficial beam pattern that is a good compromise between high-definition imagery and good fish or lure tracking. In this regard, some traditional transducer arrangements may produce a beam that is wide in one direction and narrow in another, which may provide high-definition structure, but lack the ability to track fish or lures due to the narrow beam width in one direction. The invention utilizes an array of transmit transducers that are electrically connected in series and form an effective curved emission surface and provides a more beneficial beam pattern for generating high-definition imagery but also enabling better fish and/or lure tracking (e.g., as the beam width in both directions is sufficient to enable fish/lure tracking).

The transducer housing <NUM> may also include one or more receiving transducer elements <NUM>, such as an array of receive transducer elements. The receiving transducer elements <NUM> may be configured to receive sonar returns from the first sonar signals emitted from the first emitting transducer element <NUM> and the second emitting transducer element <NUM>, <NUM>. In some embodiments, to facilitate receiving sonar returns from both the first emitting transducer element <NUM> and the second emitting transducer element <NUM>, <NUM> 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 <NUM> and the second emitting transducer element <NUM>, <NUM> 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 <NUM> and the second emitting transducer element <NUM>, <NUM> may be configured to transmit at different frequencies. For example the first emitting transducer element <NUM> may be configured to transmit at a first frequency and the second emitting transducer element <NUM>, <NUM> 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 <NUM> 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 <NUM> may be a transducer array including a plurality of individual transducer elements <NUM> arranged in a linear array. In some example embodiments, the receiving transducer element <NUM> may include a plurality of individual transducer elements <NUM> arranged in a first linear array and a second linear array, similar to the receiving transducers 314A and 314B depicted in <FIG>. 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>, a sonar signal processor <NUM> may receive, via the receiving transducer <NUM>, one or more sonar returns from the sonar signals transmitted by the first emitting transducer element <NUM> and one or more second sonar returns from the sonar signals transmitted by the second emitting transducer element <NUM>, <NUM>. In an example embodiment, the sonar signal processor <NUM> may receive the sonar return data from the receiving transducer element <NUM> 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 <NUM>, such that the sonar returns are identifiably received from the first linear array, the second linear array, and/or individual transducer elements <NUM>.

The sonar signal processor <NUM> 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 <NUM> and the second emitting transducer element <NUM>, <NUM>, and/or live 2D or 3D sonar images of the underwater environment.

In an example embodiment, the processing circuitry <NUM> may be configured to cause one or more sonar images to render (e.g., present) on the display <NUM>. In some example embodiments, the processing circuitry <NUM> may determine which sonar images to display based on user input on a user interface <NUM>. 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 <NUM> 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 <NUM> 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 <NUM> may utilize brightness, transparency, or other suitable image overlay contrasting. For example, the processing circuitry <NUM> may generate a blended sonar image with a <NUM>/<NUM> contrast, such that the sonar image data from each of the first and second sonar returns is given equal weight. The processing circuitry <NUM> 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 <NUM>, <NUM> 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 <NUM> 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 <NUM> may be configured to receive propulsion information from a propulsion system <NUM>, such as operating conditions of the main propulsion engine <NUM> and/or trolling motor <NUM>. The processing circuitry <NUM> may determine a blend ratio with a higher weight for the second sonar image data associated with the second emitting transducer element <NUM>, <NUM> when the propulsion information indicates that the vessel <NUM> is stationary, below a predetermined movement threshold, such as <NUM> knots, and/or the main propulsion engine <NUM> and/or trolling motor are not operating. Similarly, the processing circuitry <NUM> may determine a blend ratio with a higher weight for the first sonar image data associated with the first emitting transducer element <NUM> when the propulsion information indicates that the vessel <NUM> is moving greater than a predetermined movement threshold, such as <NUM> knots, and/or the main propulsion engine <NUM> and/or trolling motor are operating.

The above described transducer assembly <NUM> 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 <NUM>, the sonar images may be live, e.g., real time or near real time, 2D or 3D sonar images of underwater environment.

In some embodiments, an array of receive transducer elements (e.g., the array <NUM>) may be used to form traditional sonar images, such as one-dimensional (1D) (e.g., time-based) sonar images. For example, the sonar signal processor <NUM> may be configured to sum the sonar return data received from one or more individual receive transducer elements <NUM> of the receive array. In this regard, in some embodiments, one or more multiplexers or other devices may be used to enable selection of receipt of sonar return data from each of the individual receive transducer elements - enabling selection of the sonar return data from specific receive transducer elements.

Depending on which receive transducer elements are utilized and summed, different levels of definition of the resulting sonar image can be obtained. For example, in the situation where the array includes a large ratio of length to width (e.g., <NUM>:<NUM> or greater), then summing the sonar return data from all or most of the individual receive transducer elements results in a 1D sonar image with relatively high-definition (e.g., which may be equivalent to a sonar image formed using a linear (e.g., rectangular-shaped) transducer element). For example, the sonar signal processor <NUM> may select to receive and sum the sonar return data from all of the received elements <NUM> of the array <NUM> shown in <FIG>. By performing a straight summation of the sonar return data, the resulting summed sonar return data can be used to form a 1D (time-based) waterfall sonar image. Further, by summing the sonar return data from all the receive transducer elements, the effective beam shape corresponding to the summed sonar return data corresponds to a similar beam shape of a traditional linear (e.g., rectangular-shaped) transducer element and, thus, a similarly high-definition of sonar imagery.

Along similar lines, summing the sonar return data from a small subgroup of individual receive transducer elements (e.g., <NUM>-<NUM> elements) results in a 1D sonar image with relatively lower definition (e.g., which may be equivalent to a sonar image formed using a conical (e.g., circular-shaped) transducer element). For example, the sonar signal processor <NUM> may select to receive and sum the sonar return data from only the four receive elements 208a-d of the array <NUM> shown in <FIG>, which may correspond to the receive transducer elements that are located in the center of the array <NUM>. In this regard, a small number of receive transducer elements may be chosen and, in some cases, the center receive transducer element(s) may be chosen. By performing a straight summation of the sonar return data, the resulting summed sonar return data can be used to form a 1D (time-based) waterfall sonar image. Further, by summing the sonar return data from only the subgroup of receive transducer elements, the effective beam shape corresponding to the summed sonar return data corresponds to a similar beam shape of a traditional conical (e.g., circular-shaped) transducer element and, thus, a similarly lower-definition of sonar imagery. Notably, in addition to being commonly used, such a sonar image also produces fish arches, which is desirable to many anglers.

Notably, variations of summed sonar return data and relative positioning of the selected receive transducer elements to produce different sonar images are, thus, contemplated by various embodiments herein.

Additionally, as noted herein, the array of receive transducer elements <NUM> may be used to form two-dimensional (2D) or three-dimensional (3D) sonar return data that can be used to generate a 2D or 3D sonar image. In this regard, the sonar signal processor <NUM> may be configured to utilize sonar return data from two or more of the receive transducer elements <NUM> to generate the 2D or 3D sonar return data, such as using interferometry and/or beamforming as described herein.

In some embodiments, the marine system that utilizes such example transducer assemblies may be configured to enable selection of sonar images corresponding to each of the above example sonar images being generated, such that the array of receive transducer elements may be used to create each and/or all of the above noted sonar images, e.g., corresponding to summed sonar return data and/or 2D/3D sonar return data. A display of the system may, thus, be configured to present each of the sonar images and may be configured to simultaneously present the sonar images, as the sonar return data may be gathered and processed simultaneously.

<FIG> illustrates a transducer assembly having a transducer housing <NUM> including a forward scanning portion <NUM> and down scanning portion <NUM>. The forward scanning portion <NUM> may include an emitting element <NUM> and one or more receiving arrays 308A, 308B. The emitting element <NUM> 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 <NUM> is depicted, a transducer element configuration similar to the transducer assembly illustrated in <FIG> or <FIG> may substituted for additional functionality.

Each receiving array 308A, 308B may include a plurality of individual transducer elements <NUM>, e.g. piezoelectric crystalline structures, arranged in a linear array. In some embodiments, the individual transducer elements <NUM> may be arranged in a first linear array 308A and a second linear array 308B. A longitudinal axis of the first linear array 308A may be perpendicular to a longitudinal axis of the second linear array 308B. Similar to the operation of the receiving element <NUM> discussed above in reference to <FIG> and <FIG>, the individual transducer elements <NUM> may convert the vibrational energy of reflected sonar signals, e.g. sonar returns, into an electrical signal. The sonar signal processor <NUM> (<FIG>) may receive one or more sonar returns from the receiving transducer arrays 308A, 308B. In an example embodiment, the sonar signal processor <NUM> may receive the sonar return data from the receiving transducer arrays 308A, 308B 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 <NUM>, such that the sonar returns are identifiably received from the first linear array 308A, the second linear array 308B, and/or individual transducer elements <NUM>.

The down scanning portion <NUM> may include an emitting transducer element <NUM> and one or more receiving transducer arrays 314A, 314B. In some example embodiments, the down scanning portion <NUM> may also include a second emitting element <NUM>, which may have a different emitting face shape, such as an elongated rectangular emitting face. The emitting transducer element <NUM> and/or <NUM> may be configured and operate with the receiving transducer array(s) 314A, 314B in a manner similar to the transducer assemblies discussed in <FIG> and <FIG> and/or the down transducer assembly of the down scanning portion <NUM> discussed above.

<FIG> illustrate cross-sectional views of example transducer assemblies, such as the transducer assembly of <FIG>, in accordance with some embodiments. The transducer housing <NUM> may be configured to retain the forward scanning portion <NUM> and the down scanning portion <NUM>. When the transducer housing <NUM> is mounted to a vessel <NUM>, the down scanning portion <NUM> may face substantially downward into the body of water <NUM> in a horizontal plane parallel to the surface of the body of water, such that the downward scanning portion <NUM> transmits one or more sonar signals in a generally downward direction. The forward scanning portion <NUM> may face at least partially forward and angle out of the horizontal plane by a predetermined amount or angle, such as <NUM> degrees, <NUM> degrees, or other suitable angle, such that the forward scanning portion <NUM> transmits sonar signals into the body of water in a generally forward and downward direction.

In some instances, a blind spot <NUM> may be created by the difference in transmission and receiving angles of the forward scanning portion <NUM> and down scanning portion <NUM>, as shown in <FIG>. The blind spot <NUM> may be mitigated or eliminated by reduction of the angle difference between the forward scanning portion <NUM> and the down scanning portion <NUM>. Additionally or alternatively, the forward scanning portion <NUM>' may be curved, as depicted in <FIG>, to mitigate or eliminate the blind spot <NUM>. In an example embodiment, the forward scanning portion <NUM>' 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>. the sonar signal processor <NUM> may be configured to generate sonar image data based on each of sonar returns received from both the receiving transducer array(s) 308A, 308B of the forward scanning portion <NUM> and the receiving transducer array(s) 314A, 314B of the down scanning portion <NUM>. The processing circuitry <NUM> may receive the sonar image data from the sonar signal processor <NUM> 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 <NUM> and/or the down scanning portion <NUM>.

In some example embodiments, the sonar signal processor <NUM> and/or the processing circuitry <NUM> may generate a continuous sonar image based on both the sonar returns from the forward scanning portion <NUM> and the down scanning portion <NUM>. In one such embodiment, the sonar signal processor <NUM> and/or the processing circuitry <NUM> may register the common edge of the sonar image based on the sonar return from the forward scanning portion <NUM> and the sonar image based on the sonar return from the down scanning portion <NUM>. The sonar signal processor and/or the processing circuitry <NUM> 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 <NUM>. The processing circuitry <NUM> 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 <NUM> may determine the sonar image to render on the display based on user input on the user interface <NUM>.

In an example embodiment, the processing circuitry <NUM> 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 <NUM>. For example, the processing circuitry <NUM> may render a downscan sonar image in an instance in which the vessel <NUM> is stationary or moving less than a predetermined threshold, such as <NUM> knots, or the main propulsion engine <NUM> and/or the trolling motor <NUM> is not operating. The processing circuitry <NUM> may render a forwardscan sonar image in an instance in which the vessel <NUM> is moving greater than a predetermined threshold, such as <NUM> knots, or the main propulsion engine <NUM> and/or the trolling motor <NUM> is operating. Additionally or alternatively, the processing circuitry <NUM> may pan a continuous sonar image based on the operational condition of the propulsion system <NUM>. For example, the processing circuitry <NUM> may pan the continuous sonar image toward the downscan portion of the image when the propulsion information indicates the vessel <NUM> is relatively stationary and toward the forwardscan portion when the propulsion information indicates movement of the vessel <NUM>.

<FIG> shows a block diagram of computing device, such as user device <NUM>. The depicted computing device is an example marine electronic device <NUM>. The marine electronic device <NUM> 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 <NUM>.

The marine electronic device <NUM> 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 <NUM> framework, GPS, cellular, WiFi, 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 <NUM>.

The marine electronic device <NUM> may include a processor <NUM>, a memory <NUM>, a user interface <NUM>, a display <NUM>, one or more sensors (e.g. position sensor <NUM>, other sensors <NUM>, etc.), and a communication interface <NUM>.

The processor <NUM> 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 <NUM> as described herein. In this regard, the processor <NUM> 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 <NUM> 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 <NUM> 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 <NUM> 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 <NUM> 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 <NUM> to carry out various functions in accordance with example embodiments of the present invention. For example, the memory <NUM> could be configured to buffer input data for processing by the processor <NUM>. Additionally or alternatively, the memory <NUM> could be configured to store instructions for execution by the processor <NUM>.

The communication interface <NUM> may be configured to enable connection to external systems (e.g. an external network <NUM>). In this manner, the marine electronic device <NUM> may retrieve stored data from a remote server <NUM> via the external network <NUM> in addition to or as an alternative to the onboard memory <NUM>. 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 <NUM>, more particularly to or from a sonar signal processor <NUM>. In some embodiments, the marine electronic device may also be configured to communicate with a propulsion system <NUM> of the vessel <NUM>. 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 <NUM> may be configured to determine the current position and/or location of the marine electronic device <NUM>. For example, the position sensor <NUM> 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 <NUM>, e.g. screen, may be configured to display images and may include or otherwise be in communication with a user interface <NUM> configured to receive input from a user. The display <NUM> 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 <NUM> 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 <NUM> 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 <NUM> 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 <NUM> of <FIG> is shown as being directly connected to the processor <NUM> and within the marine electronic device <NUM>, the display <NUM> could alternatively be remote from the processor <NUM> and/or marine electronic device <NUM>. Likewise, in some embodiments, the position sensor <NUM> and/or user interface <NUM> could be remote from the marine electronic device <NUM>.

The marine electronic device <NUM> may include one or more other sensors <NUM> configured to measure environmental conditions. The other sensors <NUM> 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 <NUM> may have one or more transducers (e.g., transducers <NUM>, <NUM>), such as a plurality of scanning portions <NUM>, <NUM> (such as discussed in reference to <FIG>) and/or various emitting or receiving transducers (such as discussed in reference to <FIG>). The transducer assembly <NUM> may also include a sonar signal processor <NUM> configured to receive one or more sonar returns and determine sonar image data. In some embodiments, the sonar signal processor <NUM> may be configured to select individual transducer elements to gather sonar return data and/or cause transmission, such as through a multiplexer <NUM>. Although depicted in the transducer assembly <NUM>, it would be immediately understood by one of ordinary skill in the art, that the sonar signal processor <NUM> may be a portion of the user device <NUM>, the marine electronic device, the processing circuitry <NUM>, the processor <NUM>, or another remote device/system.

The propulsion system <NUM> may include the main propulsion motor <NUM> and/or trolling motor <NUM>. The propulsion motor <NUM> and/or the trolling motor <NUM> may include one or more sensors to measure operation or speed of main propulsion motor <NUM> and/or the trolling motor <NUM>.

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>.

<FIG> 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> may, for example, be performed by, with the assistance of, and/or under the control of one or more of the processor <NUM>, memory <NUM>, communication interface <NUM>, user interface <NUM>, position sensor <NUM>, other sensor <NUM>, transducer assembly <NUM>, sonar signal processor <NUM>, display <NUM>, and/or propulsion system <NUM>. The method may include receiving first sonar return data from one or more first sonar signals at operation <NUM>, receiving second sonar return data from one or more second sonar signals at operation <NUM>, and determining sonar image data based on both the first sonar return data and the second sonar return data at operation <NUM>.

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 <NUM> and causing presentation of the sonar image on a user interface at operation <NUM>.

<FIG> illustrates a flowchart according to example methods for operating a sonar transducer assembly according to an example embodiment. The operations illustrated in and described with respect to <FIG> may, for example, be performed by, with the assistance of, and/or under the control of one or more of the processor <NUM>, memory <NUM>, communication interface <NUM>, user interface <NUM>, position sensor <NUM>, other sensor <NUM>, transducer assembly <NUM>, sonar signal processor <NUM>, display <NUM>, and/or propulsion system <NUM>. The method may include causing transmission of sonar signals at operation <NUM>, receiving sonar return data from one or more transducer elements at operation <NUM>, processing and/or summing some or all of the received sonar return data at operation <NUM>, generating corresponding sonar image data at operation <NUM>, and causing presentation of the sonar image(s), such as on a user interface at operation <NUM>.

<FIG> illustrate flowcharts 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 <NUM> and executed by, for example, the processor <NUM>. 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 <NUM>) 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 <NUM>) 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).

In an example, 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, 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 examples, 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, 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 examples, 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, the second emitting face defines a second shape that is different than a first shape of the first emitting face. In some examples, 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, 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 examples, 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 examples, the at least one third transducer element includes a plurality of transducer elements arranged in a linear array.

In a further example, 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, 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.

Claim 1:
A system for imaging an underwater environment of a body of water, the system comprising:
a transducer assembly (102a, 102b, 102c) comprising:
an array of a plurality of transmit transducer elements (<NUM>), wherein the plurality of transmit transducer elements (<NUM>) are electrically connected in series and configured to transmit sonar signals into the underwater environment, wherein each of the plurality of transmit transducer elements (209a,209b,209c) comprises an emitting face, wherein at least two of the plurality of transmit transducer elements are mounted with respect to each other such that respective emitting faces (212a,212b) of the at least two of the plurality of transmit transducer elements are oriented in different directions (<NUM> a,<NUM>1b); and
an array of a plurality of receive transducer elements (<NUM>), wherein each of the plurality of receive transducer elements (<NUM>) is configured to receive sonar returns from the sonar signals and form corresponding sonar return data; and
a sonar signal processor (<NUM>) configured to:
receive (<NUM>) the sonar return data from each of the plurality of receive transducer elements (<NUM>) of the array; and
generate (<NUM>) sonar image data based on the sonar return data, wherein the sonar image data forms a sonar image representing the underwater environment; and
a marine electronic device (<NUM>) comprising:
a user interface (<NUM>) comprising a display (<NUM>);
a marine electronic device processor (<NUM>); and
a memory (<NUM>) including computer program code configured to, with the marine electronic device processor (<NUM>), cause the marine electronic device (<NUM>) to:
receive the sonar image data from the sonar signal processor; and
cause (<NUM>) presentation of the sonar image, based on the sonar image data.