An important aspect of commerce is the transportation of goods. In addition to railroads and trucks, vessels travelling via waterways, such as rivers, large lakes, and oceans, are capable of carrying huge quantities of commercial goods and materials. In contrast to highways for trucks and railroads for railcars, features and conditions of waterways are often not static. For example, depths of rivers or other water bodies generally change seasonally or even day to day due to variable volume flow, currents, and tides. Thus, there is generally an uncertainty regarding depths of any particular part of a river. Such uncertainty may give rise to questions such as whether there is enough depth (e.g., draft) for travel or to berth a ship at a particular location on a particular afternoon or will dredging be needed in a particular month of the year.
The disclosure will be understood more fully from the detailed description given below and from the accompanying figures of embodiments of the disclosure. The figures are used to provide knowledge and understanding of embodiments of the disclosure and do not limit the scope of the disclosure to these specific embodiments. Furthermore, the figures are not necessarily drawn to scale.
This disclosure describes techniques and systems to determine or forecast depths of vessel-carrying waterways or water bodies, such as rivers, coastal inlets, harbors, port berths, navigation channels, and canals, just to name a few examples. Some of the techniques involve a process of receiving raw, crowdsourced depth data measured by multiple vessels (e.g., boat, ship, tug, autonomous underwater or surface vehicle (AUV or ASV), etc.) and using calibrated survey data referenced to a standard vertical datum, in combination with water surface elevation data, to convert crowdsourced depth data to a standardized elevation or depth that may be universally recognized by multiple users. For example, such calibrated survey data may be referenced to NAVD88, though various embodiments described herein may use other survey data that reference other vertical datum (e.g., MLLW). Crowdsourcing generally involves a relatively large group of dispersed participants (e.g., vessels in various parts of a waterway at different times) contributing or producing depth data to achieve a cumulative result. In other embodiments, crowdsourcing need not be involved and time series data from various other sources may instead be used.
There are a number of advantages provided by using crowdsourced depth data. For example, such crowdsourcing allows for the use of existing sensors on vessels and use of depth measurements thereof that already exist in the course of normal travel of the vessels. Crowdsourcing also allows for increasing data volume and frequency while maintaining various costs. Unfortunately, each vessel generally has its own characteristics regarding its depth measurements. For example, exact locations on the river for where depth measurements were taken, location (relative to the GPS coordinate of the vessel) and depth of the transducer taking the depth measurements, the tide or elevation of the water surface at the time of the depth measurement, and other factors are generally unique for each vessel and for each depth measurement. Thus, embodiments described herein introduce the application of standardized, universal survey data to the crowdsourced depth data so that this depth data may be calibrated to this standard. In this way, substantially all the variables and inconsistencies among the multiple vessels may be removed so that depth data measured by one vessel is consistent with (e.g., in parity with) depth data measured by another vessel.
Herein, vessel depth is the distance from a depth transducer on the hull of a vessel to the bottom of the waterway underlying the vessel. Even for a specific location, measured depth generally varies, being dependent on water surface elevation, vessel draft, location of the depth transducer in the hull of the vessel, and other factors. Water level (e.g., elevation) generally changes daily and seasonally. Herein, a system may use elevation as a standardized value that is corrected to ensure geopotential parity across geographic locations and is independent of variables that affect waterway depth.
Survey data may be provided to a system by any of a number of entities, such as port authorities (e.g., Port of New Orleans) or the US Army Corps of Engineers, for example. Such survey data may be corrected to a known elevation and referenced to a standard, such as the NAVD88. Using a cloud of data points in a survey, the system may create an interpolated 2-dimensional surface of the data, such as a triangulated irregular network (TIN). NAVD88 elevations may then be applied to the TIN to create a surface that comprises NAVD88 elevations.
In some embodiments, a system may be deployed to any vessel having a processor (e.g., that executes programmable code) that is integrated with sensors or receivers to receive crowd-sourced data. System capabilities may include harvesting and packaging data that is sourced from existing sensors (e.g., including but not limited to sensors such as GPS, depth sounder, water quality, wind gage, temperature gage, etc.) aboard the vessel and transmitting data to cloud storage in real-time via telemetry (e.g., satellite, radio, and cellular, just to name a few examples). The system may be agnostic to sensor type and may utilize a standard data format, such as that associated with the National Marine Electronics Association (NMEA). The system may receive raw, crowd-sourced vessel depth data from a number of vessels. The system may filter the data, as described below, to produce a unique, crowd-sourced data set for each vessel. In embodiments where data provided by each vessel are in the form of a depth, which may have limited utility, to ensure that all vessel data are referenced to a common vertical datum), vessel depth may be converted to a NAVD88 (or other standard) elevation. For a vessel, a process for such conversion may include identifying areas of overlap between a track of the vessel and one or more points that have an established (e.g., known) elevation. For example, points with known elevation may be derived from an archived bathymetric survey that is referenced to an established vertical datum. A vessel, however, may need to cross at least one point within such a survey to convert the vessel depth to an elevation. In another example, a vessel depth measured on a fixed structure on the water bottom of known elevation (e.g., a shipwreck, a concrete revetment or other engineered structure, bridge footing, or pipeline crossing) that can be assumed to be stationary (at least during time spans or an epoch of interest) may be used as a reference elevation from which to convert vessel depth to an elevation. In still another example, an elevation of a vessel may be determined if the vessel crossed a track of another vessel that has been corrected to a known elevation. In such a case, a status may be assigned to each vessel based on the source used to establish its elevation so as to convert the vessel's depth to a value that references a universal standard vertical datum. For example, a vessel that has crossed tracks with either one or more survey points or a fixed point in the waterway of known elevation and uses either one of these for a reference to correct vessel depth to an elevation may be assigned a primary status. Determined depths or elevations of primary status vessels may be considered relatively highly accurate. A vessel that has crossed tracks with a primary vessel and relies on the reference elevation of the primary vessel at the point of the track crossing may be assigned a secondary status. Depths or elevations of a secondary status vessel may be determined by an intermediate transformation using depths or elevations of a primary vessel. Depths or elevations of a secondary status vessel may be considered to be less accurate than those of a primary status vessel because the transformation may introduce some errors. A vessel that has crossed tracks with a secondary vessel and relies on the reference elevation of the secondary vessel at the point of the track crossing may be assigned a tertiary status. Depths or elevations of a tertiary status vessel may be determined by an intermediate transformation using depths or elevations of a secondary vessel. Depths or elevations of a tertiary status vessel may be considered to be less accurate than those of a secondary status vessel because the transformation may introduce some errors. Generally, vessel status may change on a regular basis, from time to time, or based on distance travelled, and thus status may be reassigned as situations change for the vessel.
In some embodiments, a method for determining depths (which may be performed in near real-time in some implementations) of a waterway may include receiving depth data that is a part of crowdsourced depth data measured by multiple vessels in the waterway. The depth data may then be transformed to elevation data. The transforming, which may be an automatic process, may be based on an elevation standard, such as NAVD88, and a fixed location having an established elevation. Such a location may be determined from a bathymetric survey that includes the established elevation. In other situations, as mentioned above, the location may be a fixed point, such as a shipwreck or a submerged pipeline crossing, in the waterway or a crossing of a track of the vessel with a track of another vessel having an established elevation. Depths of the waterway may be determined based on the elevation data.
In some implementations, as mentioned above, the method may also include assigning a status to each of the multiple vessels based on quality of the depth data provided respectively by each of the multiple vessels. The status of a vessel, as described below, may then be considered when processing depth data measured by that vessel. For example, a primary status may correspond to a relatively high quality of the depth data, a secondary status may correspond to a relatively medium quality of the depth data, and a tertiary status may correspond to a relatively low quality of the depth data (as compared to the other data just described). Such levels of quality may be identified and considered during a process of transforming crowdsourced depth data to standardized elevation data, for example.
In some embodiments, a method for determining depths of a waterway may include receiving crowdsourced depth data measured by multiple vessels and transforming the depth data to elevation data. As described above, the transforming may be based on a standard elevation surface, such as NAVD88, and a type of established elevation point. The method may further include establishing a hierarchy of accuracy of the elevation data by categorizing, or assigning a status to, each of the multiple vessels. The categorizing may be based on the type of the established elevation point used to transform the depth data to the elevation data. For example, a vessel may be categorized as a primary status vessel, corresponding to relatively high accuracy elevation data, if the type of established elevation point is a surveyed part of the waterway or a fixed point of known elevation in the waterway. Also, a vessel may be categorized as a second status vessel, corresponding to relatively medium accuracy elevation data if the type of established elevation point is a track crossing with one of the primary status vessels. Further in the hierarchy, a vessel may be categorized as a tertiary status vessel, corresponding to relatively low accuracy elevation data (as compared to the other data just described), if the type of established elevation point is a track crossing with one of the second status vessels. Depths of the waterway may be determined based on the high, medium, and low accuracy elevation data.
In some implementations, the status of a particular vessel among the multiple vessels may change in response to an expiration of a time span of validity or the particular vessel traveling beyond a threshold distance, for example. In other implementations, vessels may move outside the region of a survey and still provide elevation “in-datum”, as long as the water surface elevation is known and vessel transducer offset is established, for example.
In some embodiments, a method for producing a bathymetric map of a waterway may include receiving crowdsourced depth data measured by multiple vessels, transforming the depth data to elevation data, compiling the elevation data with survey data, creating a digital elevation model of a bottom of the waterway, and producing the bathymetric map. The transforming may be referenced to a standard vertical datum, such as NAVD88, and an established elevation point, which may be a surveyed part of the waterway or a fixed point of known elevation in the waterway, as described above and below.
In the example illustrated in
In some implementations, the survey data may be used to generate a triangulated irregular network (TIN), which is a representation of a continuous surface made up of triangular facets (e.g., a triangle mesh).
Overlaying waterway 102, banks 116, and land 118 may be a largescale survey that includes particular reference points. Such a survey may be used as a standard reference for smaller surveys. One such survey may define elevations referenced to a standard vertical datum, which is a reference that may be used for deriving vertical positions relative to a known elevation, such as the elevations of Earth-bound features (e.g., terrain, bathymetry, water level, and built structures). An example is the North American Vertical Datum of 1988 (NAVD 88).
In some embodiments, a method for determining depths of a waterway includes receiving crowdsourced depth data measured by multiple vessels and transforming the depth data to elevation data. The transforming may be based on a standard elevation surface and a type of established elevation point. As mentioned above, the method may also include establishing a hierarchy of accuracy of the elevation data by categorizing each of the multiple vessels, the categorizing being based on the type of the established elevation point used to transform the depth data to the elevation data. As explained above, a vessel may be categorized as a primary status vessel if the type of established elevation point is a surveyed part of the waterway or a fixed point of known elevation in the waterway. A vessel may be categorized as a second status vessel if the type of established elevation point is a track crossing with one of the primary status vessels. A vessel may be categorized as a tertiary status vessel if the type of established elevation point is a track crossing with one of the second status vessels.
For example, vessel 204 may be categorized as primary status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is a fixed point of known elevation, such as point 216, which is the intersection between track 206 of vessel 204 and pipeline crossing 105, for which the elevation is known. In another example, vessel 212 may be categorized as primary status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is a fixed point of known elevation, such as point 224, which is the intersection between track 214 of vessel 212 and shipwreck 104, for which the elevation is known. On the other hand, vessel 212 may be categorized as second status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is track crossing 222 with primary status vessel 204. Additionally, vessel 212 may be categorized as second status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is track crossing 220 with primary status vessel 204. Vessel 208 may be categorized as tertiary status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is track crossing 218 with second status vessel 212. On the other hand, vessel 208 may be categorized as second status if the type of established elevation point applied to transforming the vessel's depth data to elevation data is track crossing 218 with vessel 212 while it is categorized as primary status.
As indicated above, the status of a vessel may change. In some implementations, a travel distance or time threshold may invoke a status change. For example, a vessel's status may change if a certain time has elapsed, or a certain distance travelled, since the vessel crossed an established elevation point. For instance, vessel 212 may have a primary status from crossing point 224 (the shipwreck) for a predetermined timespan (e.g., time threshold) or travel distance (e.g., distance threshold). If the timespan has passed or the travel distance has been exceeded, then the status of vessel 212 may change to secondary, for example, if track crossing 222 with primary status vessel 204 is used as the established elevation point applied to transforming vessel 212 depth data to elevation data.
As described above, a system for determining depths of the waterway may perform a method that includes receiving depth data measured by vessel 302. The system may receive the depth data from multiple sensors on the vessel, combine the data, and wirelessly transmit the data in near real-time to cloud storage or other system that includes computer memory and/or a processor. In some implementations, the data need not be transmitted in near real-time. For example, the latter case may occur if vessel 302 temporarily loses its wireless connection for transmitting the data. The data may then be stored locally on the vessel, at least until the data can be wirelessly transmitted to the cloud storage or other system. The depth data may be a part of crowdsourced depth data measured by multiple vessels. In the situation illustrated in
For example, at a location/. (not illustrated) that has an established elevation and known water surface 306, vessel 302 measures a depth Dm. The established elevation of that location, however, is Dref. Thus, an offset delta-D) is the difference between Dref and Dm (ignoring negative or positive values for the moment), with delta-D) comprising the offset 316 between the vessel transducer 308 and water surface 306 and the offset 320 between the water surface 306 to a vertical datum 318. Once offset 316 between a vessel transducer and water surface is established, in conjunction with a known offset between water surface 306 and vertical datum 318, a correction may be applied to all depth data provided by vessel 302, globally, to continuously resolve delta-D and transform depths to an established elevation, without being dependent on a location L. In some implementations, offset 316 between vessel transducer and water surface may have an associated expiry. In such a case, the offset may be validated and/or updated each time vessel 302 passes over a location/with an established elevation. In other implementations, there is no travel distance or time span limitation regarding the validity of an offset. In view of these details, the system may transform depth 312 in two ways: 1) by applying offset delta-D) to depth 312, which results in an elevation based indirectly on the established elevation at location L, water surface 306, and elevation standard 318, and 2) by applying offset delta-D) to depth 312, which results in an elevation based indirectly on the known offset 316 between the vessel transducer and water surface, and the offset between water surface 306 and the elevation standard/vertical datum 318. In some implementations, a system may continuously and automatically correct depth data using such offsets.
At 406, the system may receive raw vessel data. For example, the raw vessel data may be positioning data (e.g., GPS coordinates of the vessel) and/or depth data measured by a vessel having primary status, as described above, wherein the depth data is a part of crowdsourced depth data measured by multiple vessels. Vessel data in this raw state may be parsed into a standard format and transformed to a unified horizontal coordinate system. Vessel data in this raw state may contain duplicates, outliers, or other data points that may be removed from the data set to increase the signal-to-noise ratio. Data may be filtered to remove duplicated points and ordered by timestamp. When a vessel is stationary, a large number of data points may be collected at a single location. These points may have limited information content and may be removed from the data set using a trained, machine learning supervised classification algorithm. Data points may also not represent a true reading of the water bottom surface (e.g., outliers) and these points may be removed from the data set using a trained, machine learning supervised classification algorithm, for example.
At 408, based on the interpolated DEM created in 404, the system may, in addition to the filtering process described above, filter out vessel data corresponding to locations that do not overlap with the survey. At 410, the system may categorize the vessel (that led to the filtered data) as a primary vessel and correct the vessel's (filtered) depth data to a known elevation using points where vessel location overlaps the survey to produce primary vessel elevation data.
The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the systems and methods described herein. The foregoing descriptions of specific embodiments or examples are presented by way of examples for purposes of illustration and description. They are not intended to be exhaustive of or to limit this disclosure to the precise forms described. Many modifications and variations are possible in view of the above teachings. The embodiments or examples are shown and described in order to best explain the principles of this disclosure and practical applications, to thereby enable others skilled in the art to best utilize this disclosure and various embodiments or examples with various modifications as are suited to the particular use contemplated. It is intended that the scope of this disclosure be defined by the following claims and their equivalents.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US23/65337 | 4/4/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63362504 | Apr 2022 | US |