AUTOMATIC SURVEY DESIGN

Abstract

A method of determining the draft of a ship comprising the steps of: measuring the draft of the ship using at least one optical imaging device to generate optical draft measurement data; measuring the draft of the ship using elevation data provided by at least one GNSS or GPS device to generate elevation draft measurement data; and using the elevation draft measurement data and the optical draft measurement data to determine the draft of the ship.

Description

Description AUTOMATIC SURVEY DESIGN Field of Invention Engineering The present invention relates to the field of ship draft inspection and in particular, although not exclusively, to systems and methods for providing automated draft inspection of ships using optical and GPS / GNSS based measurements of a draft of a ship tied to a berth. Background of the Invention The draft of a ship is the distance from the waterline to the bottom of the ship's hull. During loading and unloading of the ship it is important to monitor the draft of the ship to ensure it is not excessively drafted or unstable and therefore has adequate clearance for the ports it must enter or exit during the next voyage. Manual monitoring of the ship's draft during loading and unloading is time consuming and may require personnel to measure the draft on the seaward side of the ship in a pilot boat or similar vessel. Loading of large carriers and other cargo vessels can be interrupted while a draft check is being carried out. This increases the time required to load the vessel. Automation of draft checks helps to reduce some of these issues. Brief Description of the Invention In accordance with the first aspect of the present invention there is provided a method of determining the design of a vessel comprising the following steps: measuring the design of the vessel using at least one optical imaging device to provide optical design measurement data; measure the design of the ship using elevation data provided by at least one GNSS or GPS device to provide design height measurement data; and using design height measurement data and optical design measurement data to determine the ship design. A further method may comprise using the draft height measurement data to validate the optical draft measurement data, which if validated, determines the draft of the vessel. The method may comprise the step of capturing at least one optical image of a design mark on a ship's hull using at least one optical imaging device; showing optical character recognition (OCR) processing of optical images to provide OCR data; and using the OCR data in determining optical design measurement data. The method may comprise the step of measuring the ship's design using at least one optical imaging device; measuring a distance between at least one point on a ship's hull and at least one optical imaging device; and measuring a relative angle between a first and a second position of an optical axis of the optical imaging device, wherein the first position is a predetermined position and the second position is the position of the optical imaging device when the distance between the optical imaging device and the at least one point on the hull is measured. The method may comprise positioning at least one optical imaging device and at least one laser distance measuring device on a pan and tilt platform; and operating the laser distance measuring device to measure a distance between the at least one optical imaging device and at least one point on the hull of the vessel; and using the pan and tilt platform to move the optical imaging device to a second position and using the pan and tilt platform to measure a relative angle between the first position and the second position. The first position of the optical imaging device may comprise the optical axis of the optical imaging device being disposed at an angle substantially perpendicular to a longitudinal axis of a pier on which, or adjacent to, the optical imaging device is disposed; and the measurement of the reactive axis between the first position and the second position may consist of measuring the reactive axis in a horizontal plane and a vertical plane. Methods may consist of using measurements of: i) the distance between the optical imaging device and the ship's hull; ii) the relative angle between the first position and the second position, to produce a data set of three-dimensional data from the location of at least one point on the hull surface in at least the vicinity of one set of marks. Methods may consist of using: i) measurement of the distance between the optical drawing instrument and the ship's hull; and ii) the relative angle between the first position and the second position, to determine the width of the ship's hull between the ship in relation to the design mark on the port and starboard sides of the ship's hull. The method may comprise the step of performing a transformation on at least one drawing containing at least one arrangement of design marks; The transformation uses the relative angle between the second position where the image is captured by the optical imaging device and the first position. Methods may consist of: obtain at least one image containing at least one arrangement of design marks; correcting said image for the relative angle between the second position at which the image is captured by the optical imaging device and said first position to produce a corrected image; and performing optical character recognition of the corrected image. The method may comprise the steps of: transforming the image to appear as if the hull were placed in a vertical plane such that all points on the hull appear as if they were equidistant from the point of view of the optical imaging device. The method can transform the image to show it as if it were taken with an optical imaging instrument: i) put into perspective that: a. perpendicular to the longitudinal axis of the pier against which the ship is anchored; and b. an unlimited distance from the ship's hull, and ii) operating with an unlimited zoom. The method may comprise operating a transformation to transform the image to appear as if all of the light rays forming the image were parallel to each other and perpendicular to the plane on which the image is formed. Light rays can be parallel in both horizontal and vertical planes. The method may comprise further transforming the image to show that all points on the surface of the hull of the vessel are equidistant from the viewpoint. The method may comprise measuring the draft of the vessel using elevation data comprising placing at least one GNSS or GPS device on the vessel to measure an elevation of the vessel and thereby obtain elevation data, and using the elevation data to determine the draft of the vessel. The step of measuring the draft of the vessel using the elevation data may further comprise measuring a wave to provide wave data and using the wave data and elevation data to determine the draft of the vessel. The method may comprise the steps of: locating at least two GNSS or GPS devices on the vessel at positions that are laterally displaced relative to the longitudinal axis of the vessel; measuring elevation data on the at least two GNSS or GPS devices; and using the elevation data to determine an angle of the vessel's list and thereby providing an angle of the list data. The method may comprise the step of using the data list angle and the optical draft data to determine a draft measurement of the vessel for the seaward side of the vessel. The at least one optical drafting device may be located on a wharf and the method further comprises the step of mooring the vessel at the wharf before determining said optical draft measurement and said elevation draft measurement. The at least one optical drafting device may be located in a fixed position on the wharf. At least two optical imagers can be placed on the quay in a suitable position to measure the draft marks on the bow and stern of the ship. The method can consist of the level of effort of doubling the measurement from the ship plan during the loading or unloading of the ship to provide the actual time or close to the actual time of the measurement from the ship plan. In accordance with the second aspect of the current investment, a system is provided to determine the plan of the ship, the system consists of: at least one optical imaging device placed on a pier, and at least one GNSS or GPS device; the system is adapted to operate according to the level: measuring the ship's plan using at least one optical imaging device to provide optical plan measurement data; measuring the design of the ship using elevation data provided by at least one GNSS or GPS device to provide an elevation of the design measurement data; and using elevation design measurement data and optical design measurement data to determine the design of the ship. The system can further be adapted to use the elevation draft measurement data to validate the optical draft measurement data, which if validated, determines the draft of the vessel. The system further comprises a data processing unit and a measurement stage of the ship design using at least one optical imaging device which further comprises: capturing an optical image of the design markings on a ship's hull; operating a data processing unit to perform optical character recognition (OCR) processing of optical images to provide OCR data; and the data processing unit then processes the OCR data when determining the optical design measurement data. The measurement step of the ship design using at least one optical imaging device may further comprise operating a measuring device to measure a distance between at least one point on the hull of the ship and at least one optical imaging device; and measuring a relative angle between a first position and a second position of an optical axis of the optical imaging device, wherein the first position is a predetermined position and the second position is the position of the optical imaging device when the distance between the optical imaging device and the at least one point on the hull is measured. The system may further comprise an inclined plane pan on which at least one optical imaging device is mounted and a laser distance measuring device disposed adjacent to the at least one optical imaging device; and the system may further be adapted: to operate an optical distance measuring device to measure a distance between at least one optical imaging device and at least one point on the ship's hull; to operate the inclined plane pan to move the optical imaging device between at least a predetermined first position and a second position wherein the distance between the optical imaging device and at least one point on the hull of the ship is measured; and to operate the inclined plane pan to measure the relative angle between at least the predetermined first position and the second position. In the first position the optical axis of the at least one optical imaging device may be substantially perpendicular to a longitudinal axis of the pier, or adjacent to which, the optical imaging device is located; and the relative angle measurement step between the first position and the second position may comprise measuring the relative angle in a horizontal plane and a vertical plane. The system may be adapted to use at least one measurement of: the distance between the optical imager and the hull and a corresponding measurement of the relative angle between the first position and the second position at which the distance is measured to produce a data set of three-dimensional data from the location of at least one surface point of the hull in the vicinity of at least one design mark set. The system may use a data array of three-dimensional data from at least one point on the surface of the hull to determine the width of the hull between the design marks corresponding to the port and starboard sides of the hull. The system may perform a transformation of at least one image containing at least one arrangement of design marks; the transformation uses a relative angle between the optical imaging device position where the image was taken and a first position determined in advance. The system can be customized to operate according to the stage: operating at least one optical imaging device to obtain at least one image containing at least one arrangement of design markings on the hull of the ship; and correcting said image for the relative angle between a first predetermined position of said optical imaging device and a second position at which the image is captured by said optical imaging device to produce at least one corrected image; and carrying out optical character recognition of the at least one corrected image. The system can be customized to operate at any stage: transforms the image to show it as if the hull were placed in a vertical plane so that all points on the hull appear as if they were the same distance from the point of view of the optical imaging device. The system can be customized to transform at least one image: i) to show that this was taken with an optical imaging device mounted at a point of view, namely: a) perpendicular to a longitudinal axis of the pier against which the vessel is moored; and b) an unlimited distance from the hull of the ship, and ii) to show as if the optical imaging instrument were operated with an unlimited zoom to capture at least one image from that viewpoint. The system can be adjusted to transform the image to show that all the light rays forming the image are parallel to each other and perpendicular to the plane on which the image is formed. The light rays can be parallel to each other either horizontally or vertically. The method may comprise further transforming the image to show whether all points on the hull surface are equidistant from the viewpoint. Ship design measurements using elevation data may consist of placing at least one GNSS or GPS device on a ship to measure a ship's elevation thereby obtaining elevation data, and using the elevation data to determine the design elevation measurement data. The measurement stage of the ship design using the elevation data can then consist of measuring a wave around the ship to provide wave data and using the wave data and elevation data to determine the design elevation measurement data. The system may comprise at least two GNSS or GPS devices, one of which may be located on a port side of the vessel and the other of which may be located on a starboard side of the vessel thereby providing port elevation data and starboard elevation data; and a processing device may process the port elevation data and starboard elevation data to determine an angle of the vessel's list to provide the angle of list data. The system can use the list angle data and optical draft data from a ship's berth side to determine the draft measurement data for the seaward side of the ship. The system may further consist of: at least two GNSS or GPS devices placed at separate locations spaced in a longitudinal direction from the hull to provide forward elevation data and stern elevation data; and can operate a processing unit to produce forward elevation data and stern elevation data to determine the angle of the ship's top. At least one optical imaging device may be placed on a pier suitable for anchoring the vessel. The optical imaging instrument can be placed in a fixed position on the dock. At least two optical imaging instruments may be placed on the wharf in a suitable position to measure the draft marks at the bow and stern of a vessel. The system can be adapted to allow for multiple design measurements of the ship during loading or unloading to provide real or near real time design measurements of the ship. In accordance with a further aspect of the present invention there is provided a method for determining the design of a vessel using at least one optical imaging device comprising: operating an optical imaging device to capture optical images of the draft marks on the ship's hull; performing optical character recognition (OCR) processing of optical images to provide OCR data; and using the OCR data in determining optical design measurement data for ships. Further methods may consist of: measuring the distance between at least one point on the hull and at least one optical imaging device; and measuring a relative angle between the first and second positions of an optical axis of the optical imaging device, wherein the first position is a predetermined position and the second position is the position of the optical imaging device when the distance between the optical imaging device and at least one point on the hull is measured. At least one optical imaging device may be located on a pan and tilt plane and at least one laser distance measuring device may be located adjacent to the at least one optical imaging device. The method may further comprise operating the aser distance measuring device to measure a distance between the at least one optical imaging device and the at least one point on the hull; and using a pan and an inclined plane to move the optical imaging device to a second position and using the pan and inclined plane to measure a relative angle between the first position and the second position. In the first position the optical axis of the optical imaging device may be substantially perpendicular to an on-going axis of the pier on which, or adjacent to which, the optical imaging device is positioned and measuring the relative angle between the first position and the second position may comprise measuring the relative angle in a horizontal plane and a vertical plane. Further methods may consist of using measurements of: i) the distance between the optical imaging device and the hull; and ii) the relative angle between the first position and the second position, to produce a three-dimensional data set of the location of at least one point on the hull surface at least within the vicinity of one design mark set. Further methods may consist of using measurements of: i) the distance between the optical drawing instrument and the hull; and ii) the relative angle between the first position and the second position, to determine the width of the hull between the corresponding design marks on the port side and the stardard side of the hull. The method may further comprise the stage of carrying out a transformation on at least one image containing at least one arrangement of design marks; The transformation can use the relative angle between the second position where the image is captured by the optical imaging device and the first position. The next method can consist of the following steps: obtain at least one image containing at least one arrangement of design marks; correcting the image for the relative angle between the second position at which the image is captured by the optical imaging device and the first position to produce a corrected image; and performing optical character recognition of the corrected image. The method may further comprise the step of transforming the image to show it as if the hull of the ship were placed in a vertical plane where all points on the hull of the ship are seen as if they were equidistant from the point of view of the optical imaging device. Transforms can operate to transform an image to show it as it would if taken with an optical imaging instrument: i) placing it at a certain point of view, namely: a) perpendicular to a longitudinal axis of the pier against which the ship is moored; and b) an unlimited distance from the ship's hull; and ii) operating with an unlimited zoom. Transforms can operate to transform an image to appear as if all the light rays forming the image were parallel to one another and perpendicular to the data plane on which the image is formed. Short Description of Image The present embodiment will be explained with reference to the accompanying drawings wherein: Figure 1 is a schematic showing a view of a vessel tied to a wharf; Figure 2 is a schematic showing the front view of a vessel tied to the wharf and showing the design of the vessel; Figure 3 is a schematic side view of a ship's bow tied up at the top of a pier showing a design dimension; Figure 4 is a schematic front view of the design dimensions in Figure 3 in greater detail; Figure 5a is a representation of an optical view of the design dimensions of Figure 3 obtained from a drawing instrument fixed to a pier and mounted at an angle to the design dimensions; Figure 5b is a representation of the image from Figure 5a when collected for the angle at which the image was acquired; Figure 5c is a schematic representation of the transformation attempted on the image of Figure 5a; Figure 6a is a representation of a ship without a register; Figure 6b is a representation of the registered vessels; Figure 7 illustrates a process for determining the draft of a ship using optical measurements; Figure 8 illustrates a process for automatically detecting the position of draft marks on a hull; Figure 9 illustrates a process for correcting a drawing of a design mark so that a vessel can be identified; Figure 10 illustrates a process for determining a draft mark from a draft dimension adjacent to the waterline of the vessel; Figure 11 illustrates an optical, aser and tidal (OLT) based method for determining the draft of a ship; Figure 12 illustrates a process for determining levels in a drawing and for calculating the draft of a ship; and Figure 13 illustrates a process for combining water level based draft measurements, OLT based draft measurements and GNSS based draft measurements from a ship. Full Description of the Invention Embodiments of the present invention provide systems and methods for automatically measuring the draft of a ship when docked at a pier for loading or unloading. Such embodiments may provide both optical measurements and global navigation satellite system (GNSS) measurements of a draft of a ship. Measurement results from either system may be used to validate a draft survey measurement with another system. In one embodiment a system based on GPS or GNSS is used to validate the accuracy, or the like for an error, of a draft survey measurement with an optical system. A ship's draft is the distance from the waterline to the bottom of the ship's hull (as illustrated in Figure 2). A ship's draft typically changes with loading and unloading of the ship and with changes in ballast. Typically a vessel has a draft size (300) and a Pimsoll channel marked on the hull. The draft size (300) is a series of numbers colored vertically on the hull, as shown in Figures 3 and 4. The draft of a vessel is measured by reading the number of draft sizes located at the waterline (125). A vessel typically has 6 draft sizes marked on the hull, two adjacent bow (130) (one on the port side and one on the starboard side), two adjacent stern (135) (one on the port side and one on the starboard side), and two amidships (one on the port side and one on the starboard side). A Plimsoll line is a line that indicates the maximum load for a ship. There may be several Plimsoll lines on the side of a ship marked to indicate the maximum load for when the ship is in tropical water, cold water and at different times of the year. Now referring to Figures 1 and 2 there show a ship (100) moored at a pier (105). The ship (100) has six GNSS units (115) located on its upper decks consisting of two adjacent bows of the ship (130) (one on the port side and one on the starboard side), two amidships (one on the port side and one on the starboard side), and two adjacent sterns of the ship (135) (one on the port side and one on the starboard side). The GNSS units (115) are installed when the ship arrives at port, or based on the ship being moored at the pier (105), and operate to combine GNSS positional data with a control unit (155). The GNSS units are adapted to communicate elevation, latitude and longitude data with the control unit (155) via a wireless network located at a port where the ship is moored. In this embodiment the control unit 155 is located remotely from the dock 105 and comprises a processor, a memory, an operating system and an automated design survey program. The control unit 155 may be in communication with a wireless network located at the port. In the embodiment of Figure 1, three optical imagers (110) are located at ports (105). The optical imagers (110) are located on a pan / tilt mounting unit (160). The optical imagers (110) and the pan / tilt mounting unit (160) are connected to and controlled by a control unit (155) and an automated design survey program. Alternative embodiments have a different optical imager (110), such as one or two optical imagers. The optical imaging device (110) is mounted in a fixed position on the wharf (105), or in the harbor or is movable relative to the wharf (110) and the vessel (100), and can be positioned manually by an operator adjacent to a vessel after berthing, or can be mounted on a track or rail which allows the positioning of the optical imaging device on the track or rail to be controlled by a control unit (155). In an embodiment with three optical imagers 110 , the optical imagers 110 and pan / tilt mounts 160 are positioned on, or adjacent to, the dock 105 , adjacent to the draft size marks on the vessel 300 , one at the bow 130 , one at the center and one at the stern of the vessel 135 . A control unit 155 operates each optical imager 110 and the associated pan / tilt mount unit 160 to capture one or more images of the draft size 300 . These images may be captured as a video or still image but are typically captured as a video. The control unit 155 then processes the optical images using image processing software (as further described below), including optical character recognition (OCR) software, to determine the draft marks adjacent to the waterline 125 .This provides an optically based measurement of the draft of the ship (100) at the relevant locations (referred to as bow, stern or amidships), and on the side of the ship that happens to be adjacent to the berth (harbor or starboard). The control unit 155 also obtains GNSS data from the GNSS units 115 and processes this data to determine the draft of the vessel at six draft locations on the hull. To do this, the control unit 155 may use latitude, longitude, and elevation data from the six GNSS units to fit a surface to the vessel in the vicinity of the GNSS units. This surface, in conjunction with wave data from the wave sensors 130, is used in calculating the draft of the vessel. The wave sensors 140 are typically located at the harbor or wharf 105, and provide real-time, or near-real-time, data for the relative elevation of waves. The difference between the relative level of the waterline 125 and the elevation of the surface resulting from the locations of the six GNSS units may be used to determine the height of the surface above the adjacent water level for each draft measurement.This information can be combined with an initial optical measurement of the ship's draft to identify the draft of the ship associated with a particular difference in elevation between the surface and the waves. As the ship is loaded or unloaded, changes in the elevation of the surface and the waves provide a measure of any changes in the ship's draft. As the loading or unloading of the ship progresses, GNSS-based measurements of the ship's plan can be used to verify the sequence of optical measurements of the ship's plan. Alternatively, GNSS-based measurements of the ship's plan can be substituted for an optical measurement of the ship's plan if an optical measurement cannot be obtained or is required to be inaccurate or invalid. The control unit 155 may also access GNSS data to determine the vessel's angle from the list. This is initially determined from the difference in elevation between the GNSS units positioned on the port and starboard sides of the vessel at centerline. As illustrated in Figures 6a and 6b, the difference in elevation between the starboard and port sides of the vessel can be used to calculate the vessel's list. First the difference in elevation between the GNSS units amidships is determined, this information can be used to calibrate the difference in elevation between each GNSS unit located fore and aft of the ship. This calibration is necessary as the deck and / or rails located fore and aft of the ship can slope. The effect of any slop in the deck or rail is that the misalignment of the port and starboard GNSS units will give an inaccurate reading of the ship's list angle. By correcting for any differences in the port and starboard GNSS units located fore and aft of the ship, it is possible to use the elevation data from the GNSS units to determine the list angle of the ship during loading. This is useful where, for example, one of the GNSS units amidships is out of service during loading. The angle of the hawser register (130), and the width of the ship on the waterline adjacent to the bow can be used to calculate the measurement of the plan close to the bow (130) calculating on the ocean side of the ship for example the measurement of the plan close to the stern (135) and the middle of the ship. The draft of the vessel (100) can be monitored during loading and unloading by repeating the above optical and GNSS based measurements of the vessel draft at regular intervals throughout the loading and unloading process. A draft measurement can be obtained at least once every minute during loading or unloading, and preferably more frequently than this, to provide real time or near real time measurements of the vessel draft during loading and / or unloading. An alternative embodiment locates a distance measuring device, such as a laser-based distance measuring device, adjacent to the optical imaging device 110 and the pan / tilt unit 160. The laser distance measuring device may be operated in combination with the pan / tilt unit 160 to scan the hull of the vessel 100 and generate a data set of distances from the pan tilt unit 160 to various points on the hull surface. This data may be combined with pan / tilt angle information so that the distances from the pan / tilt angle to various points on the hull, together with the relative angles of these points to a predetermined position of the pan / tilt unit are known. From this information a three-dimensional profile data set of the hull surface may be generated. Each such data typically has a resolution of at least four scan points per square meter of the vessel. The three-dimensional data array of the hull and the relative angles of the scan points on the hull for predetermined positions of the pan / tilt unit (160) (and the optical imaging device (110)) can be used to transform an optical image of the draft dimension (300) so that the image can be processed to determine the draft of the vessel. Now referring to Figures 3 and 4, shown in Figure 3 is a draft gauge (300) located adjacent to the bow (130) of the vessel (100). The draft gauge consists of meter marks, with 10 cm marks between them. In Figures 3 and 4 the 19 meter and 18 meter marks of the draft gauge can be seen with 80 cm, 60 cm, 40 cm and 20 cm marks between them also being visible. The draft dimension (300) is shown in more detail in Figure 4, which shows that the waterline (125) intersects the number 4 (i.e. 40 cm mark), which is below the 18 meter mark of the draft dimension. A 19 meter mark of the draft dimension can be seen above the 18 meter mark of the draft dimension. The 17 meter mark of the draft dimension cannot be seen as it is below the waterline (125). The waterline (125) adjacent to the number 4 below the 18 meter mark indicates that the draft of the hull is 17.4 meters. Line 170 passing through the 18.2 meter mark indicates a change in the color of the hull. Referring now to Figures 5a, 5b and 5c. Shown in Figure 5a is a view of the design dimension 300 taken with the optical axis of the optical imager 110 positioned at an angle that is neither horizontal nor perpendicular to the longitudinal axis of the pier. Figure 5b shows a transformed view of the design dimension of Figure 5a. Figure 5c is a schematic representation of the transformation performed on the view of Figure 5a to produce the view of Figure 5b. The view of Figure 5a was taken when the optical imager was positioned at Location A, with the optical imager in a position with both pan / tilt angles relative to a predetermined position. The transformation operates to adjust the view to appear as if it were taken when the optical imager 110 was positioned at Location B.The transformation operates to produce an image that appears as if it were taken by an optical imaging device positioned at a vantage point infinitely distant from the hull and the optical imaging device has an infinite zoom. In addition, the transformation can correct all points in the image to appear as if they were at the same distance from the vantage point. The effect of the transformation is that an image is produced as all the light rays from the hull surface that make up the image are horizontal and parallel to each other and originate from points equidistant from the viewpoint of the image. The transformation enhances the reliability of optical character recognition (OCR) processing performed on the numbers that make up the list size and also improves the reliability of determining the water level in the image. The transformation can also provide the relative location of pixels in the image in a Cartesian space so that the distance of each pixel to the water surface can be determined. In other words, the operation of the image correction algorithm is to make the viewpoints of all pixels directly perpendicular to the pier and parallel to the water surface at a constant distance. This transformation allows the colored design marks on the hull to be placed in the image in a vertical straight line and to be of the same relative size. The water level is also its upper edges essentially horizontal so that the water level can be determined at any point along the waterline without higher or lower average water levels at different positions along the waterline. Further more details of the methods and systems of the present embodiment are provided. In particular the system may comprise various subsystems including a machine vision subsystem, a GNSS subsystem; a waveform subsystem; a design estimation subsystem; and a user interface. Each of these subsystems will now be described in more detail. The machine vision subsystem may consist of: a) a pack sensor placed on the dock adjacent to each design mark (specifically three positions- Forward, Middle, Aft). Each pack sensor may consist of: i. a motorized pan tilting unit (PTU). ii. a visual definition light video camera with zoom metering mounted on the PTU. iii. an accurate laser distance meter (measuring device) mounted on the PTU and aligned with the camera. iv. a pencil beam spot light mounted on the PTU and aligned with the camera. v. install brackets and hardware to attach the sensor to the PTU and the PTU to the dock. vi. equipment to enable remote communication on sensors. b) . A central computer server executes software and algorithms consisting of: i. a computer capable of executing complex machine vision algorithms in parallel. ii. Pak sensor control software to send commands to the Pak sensors (e.g. to adjust pan, tilt and zoom) and to receive video and data from the Pak sensors. iii. Machine vision algorithm software to detect the position of the design mark and calculate the design from the video sensor pack and data. iv. a database for storing the results of machine vision algorithms. A GNSS subsystem may consist of: a) Mobile RTK-GNSS (Real Time Kinematic-Global Navigation Satellite System) sensors mounted on the handrails of the ship close to each of the design mark arrays (specifically 6 arrays of design marks). b) a radio network to communicate between the central computer server and the car's GNSS sensors. c) a central computer server that executes software and algorithms consisting of: i. software to communicate car RTK-GNSS sensors. ii. mathematical modeling software to convert GNSS data and wave data into design and list values. iii. a database for storing configuration data and results from mathematical modeling software. A wave subsystem may comprise a system for measuring wave levels at a port, and / or wharf, in real or near real time. This may provide wave values ​​to a central computer server via a computer system and network. A list estimation subsystem may consist of: a) software that takes draft measurement data from the machine vision sub-system and the GNSS sub-system and calculates an estimated draft for the vessel, or relevant draft measurements of the vessel; and b) a database to store the resulting estimated design parameters. A user interface subsystem consists of: a) a mobile computer (e.g. a tablet) that can be taken on-board the ship. b) a network application that operates on a mobile computer and displays in real time or near real time; i. estimated draft at each draft position ii. video of the water and draft boundary plane marks at each pier side draft mark position, preferably both original and transformed video images are displayed. iii. information about the current state of the ship's cargo (e.g. tons loaded into each hold). c) A wireless network to enable car commuters to communicate with network applications and computer control servers. Combining machine vision subsystems and GNSS subsystems enables measurements of the draft on both the dock and sea side of the ship. Now referring to Figure 7 is illustrating a process for determining the draft of a vessel at the berth and seaward side using optical draft measurement data and GNSS draft measurement data. Specifically: in step 701, a two-dimensional data set of vessel width versus design at each set of design marks is generated from the results of hull measurements taken with the machine vision sub-system; at step (702) the quayside draft is measured optically with the machine vision subsystem; and at step (703), the seaside draft is determined by correcting the quayside draft for the ship list measured with the GNSS subsystem and the distance between the draft marks on both ship sides at water level. Automatic detection of the position of the draft marks on the hull can be provided in the machine vision sub-system to eliminate or minimize the need for an operator to physically position or remotely control the pan, tilt unit (160) or zoom of the optical imaging device: Now referring to Figure 8 illustrates a process for a machine vision sub-system to automatically detect the position of draft marks on the hull. Specifically: at stage (801) the sensor pack (called optical imager (110), pan tilt unit (160) and laser distance measuring device) is aligned to detect the end of the vessel; at stage (802), a data set of images, pan angles and distance measurements is collected for a horizontal section of the vessel (100) anticipated to contain the draft mark (300) and the waterline (125); at stage (803) the pan angle and distance measurements are converted into a 3D profile of the ship's hull in a Cartesian space; at step (804), each image in the data array is transformed at a viewpoint directly in front (similar to a camera with infinite zoom, which is infinitely far from the ship, perpendicular to the length of the pier and horizontally level) using the 3D profile of the ship's hull (referred to above); at step (805), the center of the image in space is run through the transformation and the pixels per meter are kept constant in such a way that the Cartesian location of each pixel in each image can be calculated; in step (806), an Optical Character Recognition (OCR) algorithm is performed on the transformed image to determine the design marks present in the image and the position of the design marks in each image; and in step (807), an algorithm takes the design marks present and the position of the design marks in all images to calculate a near-total location of the design marks on the 3D surface of the hull. The transformation of the images causes the images to appear as if they were taken from a viewpoint directly in front of the design mark. The transformation can also stabilize the position of the design mark in the resulting image or consecutive images. This makes it easier for humans to read the images so that machine vision algorithms can be used to determine design measurements independent of the angle of the optical imager (110) for the design mark and shape the hull. Now referring to Figure 9 illustrates a process for correcting an image of the stomach. Specifically: at stage (901), a data set of drawings, pans, inclination angles and measurement data is collected for a section of the ship around the design mark. Almost all locations of the previously calculated design mark are used as starting points; at step (902), the pan and tilt angles and distance measurements are converted into a 3D profile of the ship's hull in a Cartesian space; at step (903), each image of the data array is transformed at a viewpoint directly in front of the optical imaging device (115) (similar to a camera with zoom, which is at an infinite distance from the vessel, perpendicular to the length of the quay and horizontally level) using the 3D profile of the hull referred to above; at step (904), the center of the image in space is run through the transformation and the pixels per meter are kept constant such that the Cartesian location of each pixel in each image can be calculated; at step (905), an Optical Character Recognition (OCR) algorithm is performed on the transformed image to determine the design mark positions and values. The location of the design data with respect to the 3D profile of the hull is recorded; at stage (906) pan, tilt and zoom are required to correctly capture the waterline (125) in the images calculated using the 3D proFIL, current waves and the latest estimate of the draft; at stage (907), the water and sign interface video images (e.g., water channel (125) video images) are transformed at a viewpoint directly in front of the camera (110) using a 3D profile of the hull; at step (908), an Optical Character Recognition (OCR) algorithm is executed on the transformed image to determine the positions of draft marks and values; at step (909) any residual errors in the transformation are corrected by using variations of the design mark that detect the position at the estimated position; and at step (910) the position of the design mark is run between consecutive drawings to allow the transformed drawing to stabilize (e.g. such that the position of the design mark in the drawing does not move as the ship moves through the sea). Next, the image transformation in stage (903) is explained in detail in the following stages (903a-903d): 903a) creates a grid of points in Cartesian space along the X-axis (horizontal pier) and a Z-axis (vertical), such that the grid is slightly wider than the field of view (in meters) of the original image centered at the Cartesian center of the original image. 903b) Calculate the values ​​of points along the Y axis (horizontal and perpendicular to the front end of the pier) for the grid points generated in step (903a)) using the 3D profile generated in step (902) thereby creating a 3D array of points. A fixed multidimensional polynomial is used as the 3D profile. 903c) The 3D points in step (903b) are transformed into an array of 2D points using standard 3D in 2D projection where the distance to the viewer uses the distance from the camera in the image (based on laser data) and the rotation angle uses the camera angles horizontally and perpendicularly relative to the leading edge of the pier. 903d) an array of fixed 2D points in pixel units is calculated using the points generated in step 903a) and using the pixels per meter of the image (which is known because the angular field of view of the camera is known, and the distances of various points on the hull of the ship from the camera are known. The fixed 2D points represent a point in the transformed image. Further details on the pixel paths specified in Step 904 are described in steps 904a-904g as follows: 904a) an array of 2D points moving in pixel units calculated using the 2D points in 903d). The 2D point movement indicates where the points will remain in the original image. 904b) Two multidimensional polynomials are generated that map the moving points to the fixed points. One for the horizontal pixel positions and one for the vertical pixel positions. 904c) The polynomial from 904b) is used to create two 2D arrays (one for horizontal pixel positions and one for vertical pixel positions) which map from the transformed image to the original image. For example, the value at position (1,1) for the two arrays is (23, 45), then the pixel to be placed at (1,1) in the transformed image is (23, 45) in the original image. 904d) The mapping array created in 904c) is used to determine where the pixel centers in the original image will be in the transformed image. 904e) The position of the center pixel of the original image in the transformed image of 904d) is used as the center point to express step 904c) so that the center of the original image is in the center of the transformed image. This allows the (X, Z) Cartesian coordinates of each pixel in the transformed image to be determined based on its distance from the image center and the pixels per meter scale used in steps 903d) and 904b). 904f) The mapping array created in 904e is then applied to an image of all 1's. This is to create an image cap that has 1's where a pixel in the original image corresponds to the transformed image and 0's where there is no corresponding pixel. There may be pixels in the transformed image that extend beyond the boundaries of the original image. This cap is used to ensure that portions of the transformed image that do not have a corresponding portion in the original image are ignored by the machine vision algorithm. 904g) The mapping array created in 904e) is then used to create a transformed image from the original image. The design mark values ​​can be determined by selecting a series of marks with the highest number of marks such that each design mark in the series is a value identified by its position in the series; and based on a known pattern of design marks. This allows the design mark values ​​to be determined correctly even if some of the design mark values ​​are not individually human readable. Now referring to Figure 10 illustrates a process for determining the draft mark value on the waterline of a ship. Specifically: at step (101), a COR algorithm is used to identify design mark characters in a drawing and to identify their positions in the drawing; at stage (1002) identifying and designing a value for each possible design mark character that indicates such as that in part of the design size; at step (1003) the positions of the identified design marks are checked to see if any design marks are missing; at step (1004) the missing design marks are added at the positions identified as missing a design mark; at stage (1005) the highest design mark is placed on the hull in the drawing and each possible value is given; at stage (1006), the mark of a value on each of the other design marks in the dimension is determined by its relative position to the highest placed raft mark; at step (1007) step 1006 is repeated for each of the one possible values ​​marked with the highest placed design mark; at step (1008) for each possible sequence of design marks, the sum such that each design is the design mark character required for the sequence; and at step (1009), the sequence of values ​​having the highest sum such is determined to be the correct sequence. This algorithm is applied to determine the 10 cm mark as well as the meter mark. For the meter mark the process of Figure 10 can be applied to images at different pan and tilt angles thereby allowing for corrected meter mark values ​​to be determined at the water and design mark interface (water level 125a) even if the meter marks are not individually human readable at the water and design mark interface. This is only possible given the Cartesian location of each meter mark which can be identified by the methods described above. Further details on steps 1001 and 1002 in the process dedicated to determining the design mark value at the current water level are provided. In conjunction with stage 1001: 1001a) A convolution edge filter is applied to the transformed image. This creates a grayscale image where each edge in the transformed image will have a higher numeric value. 1001b) a convolution filter, with template of different design mark numbers as kernel, is applied to the image created in step 1001a). These templates are examples of what well-formed design marks would look like if the convolution edge filter were applied to them. These templates are scaled to various sizes (smaller, same and larger) than the estimated design mark size. The output of this step is an array of images with equal values ​​for how well the areas of the edge image match the template. 1001c) A local maximum algorithm is applied to the output of step (1001b), which outputs the maximum value and position of the maximum value of the output of step (1-1b) within a small region (design mark size). 1002d) a list of possible design cues is generated based on the convolution output generated in step 1001c). In relation to stage 1002: The list of possible design marks from step 1001d) is examined to obtain all design mark overlaps. Overlapping design marks are combined into a single design mark in the list that will have a different or similar score for each possible numeric value. For example if a 2 with a score of 0.3, the other 2 with a score of 0.15 and 4 with a score of 0.8 are overlapping, they will be combined into a single design mark with a score of 0.3 for a value of 2 and a score of 0.8 for 4. The draft of a ship can be determined by two different methods. In the first method, the draft of the ship is determined by combining OCR data from video images containing draft marks with accurate distance measurements and wave measurements. This method does not require the water level to be detected in the image (this method is referred to as the OLT-OCR, aser distance and Wave method). Now referring to Figure 11 the OLT method of determining the draft of a ship is illustrated in more detail. In particular: at step (1101), the video image of the design mark is transformed and the OCR algorithm is applied as defined above such that the position and value of the design mark are detected and are constant pixels per meter to the image, and the location of the center of the image in Cartesian space is known; at step (1102) selecting a design mark and calculating the vertical Cartesian position of the selected design mark using the vertical pixel distance at the center of the image, the pixels per meter of the image and the Cartesian height from the center of the image; at step (1103), obtain the wave measurement data at step (1104) transform the wave measurement data to the same coordinates as the original Cartesian for the vertical position of the design mark selected at step 2 above; in step 1105 subtracts the wave measurement from the Cartesian height of the design mark selected in step 1102; at step (1106) determining the draft of the ship by subtracting the result of the calculation in step 1105 from the draft value of the draft mark selected in step 2; and at step (1107) the draft measurement obtained in step 1106 is calculated for a number of images over a period of time (e.g. 10 seconds) and the draft value for the measured measurement is determined as the average of the calculated draft values ​​over the period. Now referring to Figure 12 a second method for determining the draft of a ship is illustrated. Specifically a machine vision algorithm is depicted in Figure 12 that is used to determine the water level 125 in the image (and therefore the draft of the ship) by determining which draft marks are below the water. Specifically: at step (1201), the video image containing the water channel (125) of the vessel is transformed so that the viewpoint is directly in front of the optical imaging device (110) in accordance with the method discussed above; at step (1202), an OCR algorithm is used to determine the position and value of the design mark in a first image of the video; at step (1203), the position and value of the underwater design mark are estimated based on the position and value of the non-underwater design mark; in step 1204, the position of the design mark is run from image to image in the video; at step (1205), each image is analyzed to determine whether or not there is a top or bottom of each of the design mark characters under water (note that the top and bottom of the design mark used here are the locations in the image that change the most between the presence or absence of water, even in the case of very clear water); at stage (1206), the top of the draft mark and the bottom of the under water (or not) mark are used to define a boundary in the drawing where the water level will be (e.g. near the top or bottom draft mark is out of water and the top or bottom of the bottom draft mark is under water); at step (1207), analyze the differences between the images of the video to determine the location of the water level. A scale may be applied to the algorithm based on some kind of boundary detected using the upper and lower design marks; and at step (1208), the design measurement is taken as the average of the designs calculated for each image over a period of time (e.g., 10 seconds). Now referring to Figure 13, a process is illustrated to combine GNSS-based designs, OLT-based medical vision designs and machine vision-based water level designs to compute a real-time design estimate. Specifically: at stage (1301) and for each berth side draft size on the ship, the initial OLT draft readings according to the process of Figure 11 are taken at a number (e.g. 7) of different vertical positions along the draft mark. An algorithm is used to determine if the initial OLT draft is valid and to calculate for each draft size a single initial OLT draft value; at stage (1302), and for each pier side design size, the validity of an initial water level according to the process in Figure 12 is confirmed by comparing it to the initial OLT design; in step (1303), the validated initial water level designs are used to initialize the design values ​​based on GNSS; in step (1304), design values ​​based on GNSS are calculated through loading using changes in altitude from six GNSS sensors embedded on the ship to model changes in design of the ship at the design mark against the initial design; at stage 1305, the OLT video water level measurement 125 corresponds to Figure 11, and the design water level measurement corresponds to Figure 12, taken via loading: at step (1306) each draft water level measurement is compared against both the OLT draft measurement and the GNSS-based draft measurement to validate the draft water level measurement; and at step (1307), determine the draft measurement of the vessel based on the current and previously validated draft water level and GNSS-based draft. In the process of Figure 13 the initialization of the GNSS based design is continuously corrected based on the validated water level design and if a validated water level design cannot currently be calculated, the output of the automatic design checking system is compiled on the GNSS based design. Validation of three measurement methods against each other significantly improves integrity, robustness and accuracy compared to using only one method. The following paragraphs provide further details on stage (1301). The algorithm in step (1301) uses the median of the OLT design reads that are within a configurable range of the median of all OLT design readings. If there are not enough readings within the configurable range then it will be considered invalid. This method allows all readings with incorrect meter mark values ​​to be discarded and not affect the results. This is because a common failure model is for the meter value to be determined incorrectly because specifically only the meter mark in the image is compared to the nearest ten 10 cm mark. In this specification it will be understood that if any previous publication is referenced herein such reference does not constitute an endorsement that such publication forms part of the general knowledge in this field, in Australia or any other country. In the following claims and in the above description of the invention, except where the context requires otherwise by language of expression or by implication, the word “comprises” or variations thereof such as “contains” are used in an inclusive sense, for example, to specify the presence of a specified feature but not as a limitation of the presence or further addition of any embodiment of the invention.

Claims

1. A method of determining the draft of a ship comprises the steps of: measuring the draft of the ship using at least one optical imaging device to provide optical draft measurement data of the ship's draft based on an automatic detection of the position of at least one draft mark on a hull of the ship; using the optical draft measurement data to initialize elevation data provided by at least one GNSS or GPS device to provide draft elevation measurement data; and using the draft elevation measurement data to provide at least one draft measurement of the ship and then initializing the draft elevation measurement data.

2. The method as claimed in claim 1, wherein the step of measuring the ship's design using at least one optical imaging device further comprises: capturing an optical image of at least one design mark on the ship's hull; performing optical character recognition (OCR) processing of the optical image to provide OCR data for the at least one design mark; and using the OCR data in determining the optical design measurement data.

3. The method as claimed in claim 2 further comprising the steps of: determining a location in Cartesian space of at least one design mark; and using the OCR data and the location in Cartesian space of the at least one design mark in determining optical design measurement data for the design of the vessel.

4. The method as claimed in claim 3 further comprising the step of obtaining wave data and subtracting the wave data from the location of the draft mark in Cartesian space to determine an elevation of the draft mark above the waves; and subtracting the elevation of the draft mark above the waves from the numerical value of the draft mark to obtain a draft measurement of the vessel.

5. A method as claimed in any one of claims 1 to 4 wherein the measurement step of the ship design using at least one optical imaging device, comprises: measuring a distance between at least one point on the ship's hull and at least one optical imaging device; and measuring a relative angle between a first and a second position of the optical axis of the optical imaging device, wherein the first position is predetermined and the second position is the position of the optical imaging device when the distance between the optical imaging device and the at least one point on the hull is measured.

6. The method of claim 5, wherein the at least one optical imaging device is disposed on a pan and tilted plane and the at least one laser distance measuring device is disposed adjacent to the at least one optical imaging device; and wherein the method comprises: operating the laser distance measuring device to measure a distance between said at least one of the optical imaging devices and said at least one point on the hull of the vessel; and using the pan and tilted plane to move the optical imaging device to a second position and using said pan and tilted plane to measure a relative angle between said first position and said second position.

7. The method as claimed in claim 6 wherein: in the first position the optical axis of the optical imaging device is substantially perpendicular to the longitudinal axis of a pier on which, or adjacent to which, said optical imaging device is disposed; and wherein measuring the relative angle between said first position and said second position comprises measuring the relative angle in a horizontal plane and a vertical plane.

8. The method of any one of claims 5 to 7 comprising the steps of: using measurements of: i) the distance between the optical image device and the hull; and ii) the relative angle between the first position and the second position, to generate a three-dimensional data array of the location of at least one point on the surface of the hull at at least in about one array of design marks.

9. The method of any one of claims 5 to 8 comprising the steps of using: i) measuring the distance between the optical imaging device and the hull; and ii) the relative angle between the first position and the second position, to determine the width of the hull between the corresponding design marks on the port and starboard sides of the hull.

10. The method of any one of categories 5 to 9 comprises the step of performing a transformation on at least one image containing at least one design mark; the transformation uses a relative angle between a second position at which the image is captured by the optical imaging device and said first position.

11. The method of any one of claims 5 to 9 comprising the steps of: obtaining at least one image comprising at least one arrangement of design marks; correcting said image for a relative angle between a second position at which said image is captured by the optical imaging device and said first position to produce a corrected image; and carrying out optical character recognition of said corrected image.

12. The method of any one of claims 1 to 11 further comprising the step of: transforming said image to appear as if the hull of the ship were positioned in a vertical plane such that all points on the hull of the ship appear as if they were equidistant from the viewing point of the optical imaging device.

13. The method of claim 12 wherein the transformation operation is to transform the image to show it as if it were taken with an optical imaging device: i) located at a viewpoint that is: a) perpendicular to a longitudinal axis of the pier with respect to which the vessel is moored, and b) an infinite distance from the hull of the vessel, and ii) operated with an infinite zoom.

14. The method of any one of claims 1 to 12 or 13 wherein the transformation operation is to transform the image to appear as if all of the light rays forming the image were parallel to one another and perpendicular to the plane on which the image is formed.

15. The method of any one of claims 1 to 14 wherein measuring the draft of a vessel using elevation data comprises placing at least one GNSS or GPS device on the vessel to measure an elevation of the vessel and thereby obtain elevation data, and using the elevation data to determine the draft of the vessel.

16. The method of any one of claims 1 to 15 comprising the steps of: placing at least two GNSS or GPS devices on the vessel at alternate positions laterally relative to a longitudinal axis of the vessel; measuring elevation data on the at least two GNSS or GPS devices; and using the elevation data to determine an angle of list of the vessel and thereby providing an angle of list data.

17. The method of claim 16 comprising the step of using the angles from the list data and the optical draft data to determine a draft measurement of the vessel for the seaward side of the vessel.

18. The method of any one of clauses 16 or 17 comprises the step of using elevation data from at least two GNSS or GPS devices to determine a crest angle of the vessel and thereby providing an angle of crest data.

19. The method as claimed in any one of the foregoing claims, comprising the step of providing for duplicating the measurement of the ship's draft during loading or unloading of the ship to provide an actual or approximate time measurement of the ship's draft.

20. A system for determining the draft of a ship, the system comprising: at least one optical imaging device located on a quay, and at least one TGNSS or GPS device; the system is adapted to: measure the draft of the ship using at least one optical imaging device to provide optical draft measurement data based on an automatic detection of the position of at least one draft mark on a ship's hull; use the optical draft measurement data to initialize the elevation draft measurement data provided by the at least one GNSS or GPS device; and use the elevation draft measurement data to provide at least one measurement of the ship's draft which is then used at the initialization stage of the elevation draft measurement data.

21. The system as claimed in claim 20 wherein said system further comprises a data processing unit and wherein the ship's drft measurement uses at least one optical imaging device to provide optical draught measurement data further comprises: capturing an optical image of at least one draught mark on the ship's hull; operating the data processing unit to perform an optical character recognition (OCR) operation of the optical image to provide OCR data for the at least one draught mark; and processing said OCR data to provide optical draught measurement data.

22. The system as claimed in claim 21 further adapted to: determining a location in Cartesian space of at least one draft mark; and using the OCR data and the location in Cartesian space of the at least one draft mark in determining optical draft measurement data for the draft of the vessel.

23. The system as claimed in claim 22 further adapted to obtain wave data, and to subtract the wave data from the location of the draft mark in Cartesian space to determine the elevation of the draft mark above the waves; and to subtract the elevation of the draft mark above the waves from the numerical value of the draft mark to obtain a draft measurement of the vessel.

24. The system as claimed in any one of claims 20 to 23 wherein measuring the draft of the vessel using at least one optical imaging device to provide optical draft measurement data further comprises: operating a measuring device to measure a distance between at least one point on the hull of the vessel and at least one optical imaging device; and measuring a relative angle between first and second positions of an optical axis of the optical imaging device wherein the first position is a predetermined position and the second position is the position of the optical imaging device when the distance between the optical imaging device and the at least one point on the hull is measured.

25. The system as claimed in claim 24 wherein said system further comprises an inclined plane pan on which at least one optical imaging device is mounted; and a laser distance measuring device disposed adjacent to said at least one optical imaging device; and wherein said system is further adapted: to operate the aser distance measuring device to measure a distance between said at least one optical imaging device and at least one point on the hull of the vessel; to operate the tilt pan unit to move the optical imaging device between at least a predetermined first position and a second position wherein the distance between said optical imaging device and at least one point on the hull of the vessel is measured; and to operate the pan and the inclined plane to measure a relative angle between said at least the predetermined first position and the second position.

26. The system as claimed in claim 25 wherein in the first position the optical axis of the at least one optical imaging device is substantially perpendicular to a longitudinal axis of a pier on which, or adjacent to which, the optical imaging device is disposed; and wherein measuring the relative angle between the first position and the second position comprises measuring the relative angle in a horizontal plane and a vertical plane.

27. A system as claimed in any one of claims 24 or 25 further adapted to obtain at least one measurement of a distance between the optical imaging device and the hull and a corresponding measurement of a relative angle between the first position and a second position wherein the distance is measured such that the at least one measurement produces a data array of three-dimensional data of the location of at least one point on the surface of the hull of the vessel at least in the vicinity of the array of design marks.

28. The system as claimed in clause 27 is adapted for the use of a three-dimensional data array from at least one point on the hull surface in determining the width of the hull between the relevant design marks on the port and starboard sides of the hull.

29. The system as claimed in any one of claims 24 to 28 further adapted to provide at least one image of the hull comprising at least one arrangement of design marks for the relative angle between the position of the optical imaging device at which the image is taken and a first predetermined position.

30. A system as claimed in any one of claims 20 to 28 further adapted to: operating at least one optical imaging device to obtain at least one image comprising at least one arrangement of design markings on the hull of the ship; and correcting said image for a relative angle between a predetermined first position of the optical imaging device thereby producing at least one corrected image; and carrying out optical character recognition of the at least one corrected image.

31. The system of any one of claims 20 to 30 further adapted to: transforming said image so that all points on the hull of the vessel appear as if they were equidistant from the viewing point of the optical imaging device.

32. The system of any one of claims 20 to 31 further adapted to transforming the at least one image: i) to show as if it were taken by an optical imaging device positioned at a viewpoint that is: a) perpendicular to a longitudinal axis of the wharf against which the vessel is moored; and b) an infinite distance from the hull of the vessel, and ii) to show as if said optical imaging device positioned at said viewpoint were operated with an infinite zoom when capturing the at least one image.

33. The system of any one of claims 31 or 32 further adapted to transform the image to appear as if all of the light rays forming the image were parallel to each other and perpendicular to the plane on which the image is formed.

34. A system as claimed in any one of claims 20 to 33 wherein it is further adapted to receive elevation data from at least one GNSS or GPS device located on a vessel to measure an elevation of the vessel, and to use the elevation data to determine a design elevation measurement data for the vessel.

35. A system as claimed in any one of claims 20 to 34 further adapted: to receive data from at least two GNSS or GPS devices located on a vessel such that at least one GNSS or GPS device is located on a port side of the vessel and at least one GNSS or GPS device is located on a starboard side of the vessel, to provide port elevation data and starboard elevation data; and to process the port elevation data and starboard elevation data to determine an angle of the vessel's list and to provide an angle of the list data.

36. The system as claimed in claim 35 further adapted to use the angles from the list data and the optical draft data from a quayside of the vessel to determine the draft measurement data for the seaside of the vessel.

37. A system as claimed in any one of claims 35 or 36 further adapted: to positioning at least two GNSS or GPS devices at separate locations spaced longitudinally from the hull to provide forward elevation data and stern elevation data; and to processing the forward elevation data and stern elevation data to determine a pitch angle of the vessel.

38. A system as claimed in any one of claims 20 to 37, further adapted to provide for duplicating the measurement of the ship's draft during loading or unloading to provide a true or near true time measurement of the ship's draft.

39. A method of determining the draft of a ship using at least one optical imaging device comprising: operating the optical imaging device to capture an optical image of at least one draft mark on the ship's hull; performing optical character recognition (OCR) processing of the optical image to provide COR data for the at least one draft mark; determining a location in Cartesian space of the at least one draft mark; using the OCR data and locating in Cartesian space the at least one draft mark and determining optical draft measurement data for the ship's draft.

40. The method as claimed in claim 39 further comprising: measuring a distance between at least one point on the hull and at least one optical imaging device; and measuring a relative angle between a first and a second position of an optical axis of the optical imaging device, wherein the first position is a predetermined position and the second position is the position of the optical imaging device when the distance between the optical imaging device and the at least one point on the hull is measured.

41. The method as claimed in claim 40 further comprising the steps of obtaining wave data and subtracting the wave data from a draft mark in Cartesian space to determine an elevation of the draft mark above the waves; and subtracting the elevation of the draft mark above the waves from the numerical value of the draft mark to obtain a draft measurement of the vessel.

42. The method of any one of claims 40 or 41 wherein the at least one optical imaging device is disposed on a pan and inclined plane and the at least one laser distance measuring device is disposed adjacent to the at least one optical imaging device; and wherein the method comprises: operating the laser distance measuring device to measure a distance between the at least one optical imaging device and at least one point on the hull of the vessel; and using the pan and inclined plane to move the optical imaging device to a second position and using the pan and inclined plane to measure a relative angle between said first position and said second position.

43. The method as claimed in claim 42 wherein: in the first position the optical axis of the optical imaging device is substantially perpendicular to the longitudinal axis of the pier at or adjacent to which said optical imaging device is positioned; and wherein measuring the relative angle between the first position and the second position comprises measuring the relative angle in a horizontal plane and a vertical plane.

44. The method of any one of claims 40 to 43 further comprising the steps of: using measurements of: i) the distance between the optical imaging device and the hull; and ii) the relative angle between the first position and the second position, to produce a three-dimensional data set of the locations of at least one point on the hull surface and at least in about one row of design marks.

45. The method of any one of claims 40 to 44 further comprising the steps of using: i) measuring the distance between the optical imaging device and the hull; and ii) the relative angle between the first position and the second position, to determine the width of the hull between the corresponding design marks on the port and starboard sides of the hull.

46. ​​The method of any one of claims 40 to 45 comprising the step of performing a transformation on said at least an image comprising said at least one arrangement of design marks; the transformation utilizes a relative angle between said second position at which said image is captured by said optical imaging device and said first position.

47. The method of any one of claims 40 to 46 comprising the steps of: obtaining at least one image containing at least one arrangement of design symbols; correcting said image for a relative angle between a second position at which the image is captured by the optical imaging device and said first position to produce a corrected image; and carrying out optical character recognition of said corrected image.

48. The method of any one of claims 39 to 47 further comprising the step of: transforming the image to show said image as if the hull of the vessel were placed in a vertical plane such that all points on the hull of the vessel are visible if they are equidistant from the viewing point of the optical imaging device.

49. The method of claim 48 wherein the transformation operations for transforming the image to appear as if it were taken with an optical imaging device i) located at a viewpoint, namely: a) perpendicular to a longitudinal axis of the pier against which the vessel is moored, and b) an infinite distance from the hull of the vessel, and ii) operating with infinite zoom.

50. The method of any one of claims 48 or 49 wherein the transformation operation is for transforming the image to appear as if all of the light rays forming the image were parallel to each other and perpendicular to the plane on which the image is formed.

51. The method of any one of claims 39 to 50 further comprising the step of measuring the draft of the vessel using elevation data provided by at least one GNSS or GPS device to provide elevation draft measurement data; and using the elevation draft measurement data and the optical draft measurement data to determine the draft of the vessel.

52. The method of section 51 further comprises the step of using the draft elevation measurement data to validate the optical measurement data, which if validated, determines the draft of the vessel.

53. The method of any one of clauses 51 or 52 further comprising the steps of: locating at least two GNSS or GPS devices on a vessel at positions that are laterally offset relative to a longitudinal axis of the vessel; measuring elevation data on the at least two GNSS or GPS devices; and using the elevation data to determine the angle of the vessel's list and thereby provide the angle of list data.

54. The method of claim 53 comprising the step of using the angles from the list data and the optical draft data to determine a draft measurement of the vessel for the seaward side of the vessel.

55. The method of any one of claims 53 or 54 further comprising the step of using elevation data from at least two GNSS or GPS devices to determine a zenith angle of the vessel thereby providing the angle of zenith data.

56. A method as claimed in any one of claims 39 to 55 further comprising the step of providing for duplicating the measurement of the ship's draft using both elevation draft measurement data and optical draft measurement data during loading or unloading of the ship to provide a true or near true time measurement of the ship's draft.