Method of visualization of navigational situation in ship handling

FIELD: ship handling.

SUBSTANCE: proposed method includes storage of electronic radar chart of terrain, determination of radar antenna position, correlation of specific features of terrain and points of interest; electronic radar chart of terrain is formed during processing radar information and is stored in form of sequence of radar images recorded during test run of ship equipped with surveillance radar, personal computer, equipment for tie-in of surveillance radar with personal computer and equipment of satellite navigational system. Then, present radar image is compared with electronic radar chart to estimate deviation of ship from preset route and reliability of information received from satellite navigational system and surveillance radar. Position of surveillance radar antenna, coordinates of radar image centers used for forming electronic radar chart of terrain and center of present radar image are determined by tie-in of surveillance radar with personal computer and satellite navigational system, with display of ship's position, her coordinates, heading and speed at superposition of present radar image whose center is tied-in to geographic coordinates determined by satellite navigational system, registration of image with navigational electronic chart on geospatial information carrier where visualization of change of actual depth in fixed point of water basin in time is carried out, isolines of maximum tide fluctuations and surface of tide fluctuations, height of tide are plotted. Some areas of water basin where actual depth is lesser than permissible magnitude (draft plus safe depth) are determined. Structure of storage of geospatial information includes conversion of flat scanning of Earth to multilevel embedded squares each of which is indexed by code which is just longer Guilbert's curve for this square. Index thus found is used for finding objects having index with prefix equal to index of preset area.

EFFECT: enhanced efficiency.

The invention relates to the field of navigation and can be used in the development of the autopilot, when carrying out hydrographic work, to improve the safety of navigation of tankers.

Famous visual navigation device, in which the evaluation of the navigation environment is performed by comparing the current radar image radar map [1], which requires a lot of personal experience of the Navigator, as in radar karge, and in the radar image, the exact binding to the coordinates.

There is a method of visualization of the navigation situation in which the current radar image is combined with the approximated electronic navigation map, the original information which is stored on magnetic or hard media [2]. The use of the data card is connected with certain difficulties, as they are made by the developer and navigation system for each specific navigation area on preliminary applications.

There is also known a method of visualization of the navigation situation in which the current radar image is overlaid on traditional navigation map whose image is taken by a television camera [3]. The method is time consuming, as burdened manual operations associated the replacement card, requires conditions on the adjustment of the television camera and operational changes navigation AIDS navigation does not provide input proofreading.

In the known method of visualization of navigation AIDS through the device containing the radar antenna unit for storing maps, a compass, a unit for determining the position of the radar antenna, indicator, unit of input data, determining interest point location, and a controller, which generates on-screen indicator radar scan and image maps and places of interest to the dot on the radar scan at the corresponding point on the terrain map, resulting in a radar target, characteristic features of the landscape and the point of interest may be correlated [4].

The disadvantage of this technical solution is the need of comparing information obtained in different systems, as well as the characteristic point on the terrain is mapped with radar image characteristic point may not be in the center of the radar image.

Known number of technical solutions visualization navigation environment, based on the pairing e-map navigation system with radar image is available, and also autorenewal, and external (radio navigation and satellite navigation system) and Autonomous navigation tools (course, log, depth sounder) [5, 6]. Due to the fact that in these technical solutions used in the imposition of the current radar image, the center of which is tied to geographic coordinates determined by external navigation systems, the navigation electronic map significantly increased the information content of the navigation parameters and allows the graphical display of the trajectory of movement of the vessel, as well as movement along pre-selected route (software included).

However, existing electronic navigational charts, as a rule, are recorded on the factory equipment and stored on diskettes ROM. On a single floppy disk can store up to seven e-cards [7]that allows the use of well-known visualization system navigation situation mainly in the navigation areas are not burdened with numerous navigational hazards caused by traditional navigation map. As rightly emphasized in [8, p.2], "currently available electronic navigation maps cover a small part of the territory of the Russian Federation", which limits the use of these systems, despite their higher informationist is compared with radar terrain image.

There is also known a method of visualization of the navigation conditions in the navigation [8], in which the visualization of the navigation situation when the navigation is done by creating a monitoring passage of a vessel along a given trajectory electronic radar maps, in the form of a sequence of radar images, the coordinates of the centers of which are determined using a satellite navigation system, imposing on her current radar images obtained during the passage of a vessel along a given trajectory, the coordinates of the centers of which also receive from the satellite navigation system, and subsequent measurement matches the current radar image radar and electronic maps, which is judged on the ship deviates from the set route, and on the reliability of the information obtained from satellite navigation systems and radar of the circular review, and the position of the radar antenna circular view, the coordinates of the centers of radar images used to create electronic radar maps, and the center of the current radar image is determined by the pairing radar circular scan with PC equipment and SNA. If this achievable technical result of the invention is to improve the accuracy and reliability of the display is the first navigation information.

Using the known method of visualization of the navigation conditions in the navigation for vessels of small tonnage actually gives a positive effect. However, when it is used on ships with a large displacement due to the presence of "dead zones" when working radar of the circular review, due to the installation height of the antenna, and noise arising from the construction of the deck superstructures, especially when navigating in confined in the navigation regard to the circumstances of the probability of obtaining a reliable radar data is significantly reduced.

In addition, this method allows you to achieve a technical result used in the navigation of a vessel in the coastal zone, as radar map of the area can be created at a steady grip radar of the circular review coastal navigational software or at least the coastline. In the open sea, the creation of electronic maps for radar data through the control passage of the vessel is not practicable, due to the lack of coastal landmarks.

For vessels of large tonnage, and especially for ships carrying dangerous goods, when passing narrow places, fairways and approach to remote devices oil and gas terminal output, articulating what her navigation navigation safety in these areas should be excessive and continuous for making only the right decisions to ensure navigational safety of navigation.

The objective of the proposed technical solution is to increase the reliability of the displayed navigation information by expanding the functionality of the method.

The problem is solved due to the fact that the visualization of the navigation conditions in the navigation, including the storage of electronic radar maps, positioning the antenna of the radar station (radar) circular view, the correlation characteristic features of the terrain and points of interest, when applying the current radar image on the electronic radar map of the area based on the position of the radar antenna circular view, with electronic radar map of the area create in the processing of radar data and store in a sequence of radar images recorded in the control passage given trajectory vessel, equipped with a radar of the circular review, PC, hardware interfacing radar pie review PC equipment and satellite navigation system (SNS), while the coordinates of the centers of radar images used to build electronic radar maps, receive from the SNA, and when applying the current radar image on the electronic radar map terrain. is, the center of the current radar image also receive from the SNA and placed in a point with the corresponding coordinates on the electronic map, and then estimate the coincidence of the current radar image radar and electronic maps, which is judged on the ship deviates from the predetermined route and the accuracy of the information received from the SNA and radar of the circular review, and the position of the radar antenna circular view, the coordinates of the centers of radar images used to create digital maps, and the center of the current radar image is determined by the pairing radar circular scan with PC equipment and SNA, with the display position of the vessel, its coordinates, speed, of course when applying the current radar image, the center of which is tied to geographic coordinates, defined by the SNA, the combination of radar images with the navigation electronic map stored on the media of geospatial information, which render the changes over time of the actual depth at a fixed location area, the construction and visualization of contour largest astronomical conditions scale tidal fluctuations and surface tidal fluctuations, tide height, determination and visualization of the area of the waters for some time, where the actual depth is less than acceptable (sediment plus safe depth), and the structure of the storage of geospatial information includes converting the flat surface of the Earth on a hierarchical nested squares, each of which is indexed by the code, which is the length of the Hilbert curve for this square, the determination of the index of the minimum area of a square, which entirely contains the specified area, and found the index to find the objects with the index with a prefix equal to the index of the specified field.

Distinctive features in comparison with known methods of rendering the navigation of the situation is that render the changes over time of the actual depth at a fixed location area, the construction and visualization of contour largest astronomical conditions scale tidal fluctuations and surface tidal fluctuations, the height of the tide at the time, detect and visualize areas the waters for some time, where the actual depth is less than acceptable, and the structure of the storage of geospatial information includes converting a flat scan the Earth's surface on a hierarchical nested squares, each of which is indexed by the code, which is the length of the Hilbert curve for this square, the definition is the minimum indexa the area of a square, which entirely contains the specified area, and found the index to find the objects with the index with a prefix equal to the index of the specified area that allows you to store a significant amount of cartographic information with the opportunity to enter the necessary corrections due to changes in navigational conditions, to perform the automatic generalization of natural objects defined geographical coordinates when rendering, with the possibility of transition from one scale to another with the assessment of the margin of error on a specific scale.

In the known methods of visualization of the navigation conditions in the navigation to achieve the technical result consists in increasing the accuracy and reliability you need to store large amount of data in a permanent medium. The problem of data storage is that for solving the problem of visualization of geospatial information you want to load into RAM. In the General case, a large amount of geospatial information does not allow to download it fully operational if, in the particular case, if this can be done in marine conditions, the time required to load, exceeds the allowable value. In addition, be aware that large amounts of geospatial information the purpose, loaded into memory, dramatically slow down the PC. The resolution of this problem is connected with the special structure of storage of geospatial data on the external media, and special algorithms to search for and select this storage structure of the set of geospatial data, which is needed to solve a specific current navigation task.

Traditional ways of presenting information in a relational form is not effective, because geospatial information is multidimensional. Existing views of multidimensional data in the form of multidimensional information trees (e.g., k-d-B-tree), is also not effective for time on the search and selection for output rendering.

The claimed technical solution vector representation of geospatial information based on the display of points in the multidimensional space in terms of one-dimensional cut-Hilbert curve. Such mapping allows you to build an efficient storage structure multi-dimensional information on an external drive and algorithms request procedure requirements to minimize memory and time.

In addition, for large vessels carrying dangerous cargo, essential navigation parameters to ensure safe navigation, especially in constrained what's in the navigation respect to the conditions, is the actual depth and the height of the tide. In the known methods of visualization of the navigation conditions in the navigation, and if possible to take into account tidal fluctuations, only for individual coastal points with known harmonic constants. Extrapolation of point values of the tide on the open waters of the illegal, due to the fact that tidal fluctuations on the open seas have complex spatial temporal distribution.

The method is implemented as follows.

When the vessel is EN route, as in the known method [8], perform the mapping information about the current position and the electronic radar maps obtained by defining parameters by radar of the circular review and apparatus of the SNA.

Combine the device imaging radar map of the area with electronic navigation map, which is stored on external media such as CD or hard drive. Storage on an external storage media is performed using b-tree, based on a hierarchical principle of storage, which is that:

- flat scan the Earth's surface is broken into a hierarchical nested squares similar to the construction of the Hilbert curve. Each square is indexed by the code, which is the length of the Hilbert curve for this kV is dratha;

see geospatial objects and determines the index of the minimum area of the quadrant, which completely contains the object. The object is assigned the index of the matching quadrant.

To search in a given spatial region searching the following:

- defines the index of the minimum area of the quadrant, which entirely contains the specified area;

- found in the index are objects of an index with a prefix equal to the index of the specified field.

This loads only the objects that intersect with a given area and each quadrant corresponds to some level of resolution (scale visualization), which allows for larger areas do not download small size objects by setting limits on the length of the suffix index.

When you change the positioning of a given region (scanning overview of the first modified set of small quadrants, and a set of large remains unchanged. Therefore, large objects should not be overloaded, and performed search and download only relatively small for the current scale of interest. The same is true if you change the scale in the render window. While downloading only the minimum required set of objects can support multiple different scales visualization one area is I. Because the location of the indexes in an index sequential file, the reference to the external memory single read search indexes.

The storage structure of geospatial data on external storage media includes a metadata file, the index file (the relationship between objects and hierarchical quadrants split), the file descriptions in the quadrants), the file with geospatial data (coordinates and attributes), as a source of interest and generalized that allows you to increase the memory and to build a flexible system for handling requests, taking into account the current available memory and implemented speed operations for handling requests.

The structure of the metadata file of the layers includes the minimum crushing, the range of hierarchical indexes stored in RAM, the number of layers, number of layer, layer ID, layer name, layer type (point, line, polygon), the original scale, the number of files storage, ordinal, scale, name (path) of the file storage, the maximum diameter of the object, the minimum distance, the number of gradations of the scale, the number of cartographic signs, serial number, upper scale lower scale reference map token.

The structure of the index file (for all layers) is a hierarchical index of the square (starts the first index is 0), the starting offset in data file descriptions of the objects in the box end offset of the data in the file descriptions in the square.

File descriptions in quadrants includes a hierarchical index of the square, the code data (objects, no objects in the box), if there are objects, and the number of layers, number of layer, layer ID, the number of objects that are commensurate with the size of the square, the sequence number of the object code object in the layer. the type of the object (the entire object, the part of the object, the square completely falls within the polygon, the code of the underlying polygon is to fill the number of the scale, ordinal scale, the scale value, the starting offset in the object data file storing data for the entire object or a sequence number starting point for the partial object, the end offset of the object data file storing data for the entire object references to objects on the lower level.

Information about geophysical objects in addition to the space-time coordinates includes a vector of characteristics describing the actual geophysical entity object. In the General case, each object has its own set of these characteristics, which are digital and text data type. As the search object by the given vector (exact match) or subvector (the task of finding inaccurate showpad is that there is a complex algorithmic problem, for its solution is based suffix tree representation of the vector of characteristics in the form of a string.

The procedure of automatic natural generalization of linear features is implemented in MatLab language.

Linear objects on the navigation map is represented by an ordered set of geographic coordinates. The number of pairs of coordinates in the set corresponds to the original scale. When you move to a smaller map scale should be reduced according to the scale of generalization, the number of pairs of geographic coordinates that describes the object. For this the procedure of excluding the number of points that allow you to save the visible structure of sinuosity of line, and area features in the area. The procedure, which satisfies these requirements is the concept of the ordering of points on representativeness in the formation of a graphical image of the object, and is as follows.

Each linear object (line or polygon) occupies an area corresponding to the area of its convex hull. The set of points of the convex hull of the object is the minimal set of points that represents the object on a minimal scale. This set can be visualized only if the area in pixels of the convex hull more, some specified value (the free option). When you zoom in on the Mac is Taba, the corresponding visualization of the convex hull to the original scale of the map, the number of points in the approximation should be increased, so that new points were added to the list of already rendered, which is as follows.

When you zoom in for each visualized pair of points is the point most remote from the straight line connecting these two points. If this distance is greater than the permissible error on this scale, the point is rendered, otherwise not. This procedure is a modification of the algorithm for the assessment of global fractal dimension of the curve. Therefore, the power law changes the line length remains invariant by construction, and therefore, for polygons, the area will not be enough to change as the areas of triangles, "chaotic" add or "deductible" triangles at each step small enough. At the same time, the number of points describing the curve changes dramatically. This procedure can be performed in the preprocessing stage, and at each iteration step to keep the distance from the added point to the appropriate line. Since the implementation of this procedure may result in the intersection, after its execution, it checks the intersections and their correction by means of ascribing points forming the overlapping areas takoh the larger distance values, which does not intersect. If you know the distances to points, then the proper procedure generalization reduces to the estimation of the margin of error for the scale visualization, selection of points for which the distance is greater than or equal to the error value, and visualization of the curve on the basis of these points.

When the automatic generalization of artificial objects (fenced testing sites and recommended ways of swimming), because such objects is a small number, they are classified in order of importance, according to which regulated their visualization scale. The procedure of preprocessing is to calculate for each object, its length and creates a list of the indexes of the objects in ascending order of length. In addition, for all layer objects is calculated the total area of the objects is equal to the sum of the lengths of each object on the surface of the Earth, corresponding to one pixel in the original scale of the map.

The imaging procedure is that for the entire layer is calculated the total area of the objects is equal to the sum of the lengths of each object on the surface of the Earth corresponding to a single pixel in the current map scale. Render only those objects, the sum of the squares of equal area to the original scale of the map. To do this is use a list of indexes, obtained at the preprocessing stage.

Besides the visualization of cartographic information printed on the navigation map, you can also define, visualize and save in a file the actual depth at a given path of movement of the vessel by pre-calculating tides, by means of a numerical method for calculating the spatial-temporal distribution of tidal fluctuations on the open water area on the harmonic constant at coastal stations sea level observations, which provides the possibility of pre-calculating the actual depths of the sea, as the amount of tidal fluctuations and navigation (map) depth at any point in the waters of the sea at any time. This ensures calculate the actual depth of the sea at any point at any point in time; identifying and mapping areas of the waters, on which the actual depth under all tidal situations will be less valid, always more valid and regions, occupying an intermediate position (in those areas of the actual depth can be smaller and more valid depth depending on the phase of the tide); identification and mapping of areas of waters for some time, at which the actual depth is less valid (sediment plus safe depth); identification and visualization izmeneniya time the actual depth at a fixed location area; the construction of isolines largest astronomical conditions scale tidal fluctuations in the water area, contour tidal fluctuations; the construction and visualization of surface tidal fluctuations in the waters; the animation of the position of the contour and the surface height of the tide in time on the water.

In contrast to known methods of visualization of the navigation conditions in navigation, in the present method allows the visualization not only radar maps, but almost no simplified navigation maps with their combination, as well as visualization of tidal fluctuations on the seas, which increases the reliability of navigation. This option is especially important for ships carrying dangerous goods. The method can also be used when carrying out hydrographic work. The practical implementation of the method carried out in the North sea.

Sources of information

1. Sazonov, A., Rodionov A.I. automation of navigation. M, Transport, 1977, p.194-196.

2. Pies N.N., Kernevez CENTURIES Navigation system for hydrofoil/zarubezhnoye Voyennoye Obozreniye, No. 4, 1986, p.58-59.

3. Solntsev A.N., Pies NN. Automated navigation system UNKN-94 / Notes on hydrography. L., GUNiO MO of the Russian Federation No. 244, 1988, p.29-33.

4. U.S. patent No. 5179385.

6. Current status and development trends of foreign funds and navigation systems of mobile objects for military and civilian purposes./Alexandrov A.S., Arno BORN, Vasiliev IE and other L., GUNiO MO of the Russian Federation, 1994, pp.92-100.

7. Receiver equipment GP-1500. The prospectus of the company "Decca Radar", 1989.

8. RF patent №2207585.

The visualization of the navigation conditions in the navigation, including the storage of electronic radar maps, positioning the antenna of the radar station (radar) circular view, the correlation characteristic features of the terrain and points of interest, when applying the current radar image on the electronic radar map of the area based on the position of the radar antenna circular view, with electronic radar map of the area create in the processing of radar data and store in a sequence of radar images recorded in the control passage given trajectory vessel, equipped with a radar of the circular review, PC, hardware interfacing radar circular scan with PC equipment and satellite navigation system (SNS)while the coordinates of the centers of radar images used to build electronic radar maps, produces the t from SNA and when applying the current radar image on the electronic radar map of the area center of the current radar image also receive from the SNA and placed in a point with the corresponding coordinates on the electronic map, and then estimate the coincidence of the current radar image radar and electronic maps, which is judged on the ship deviates from the predetermined route and the accuracy of the information received from the SNA and radar of the circular review, and the position of the radar antenna circular view, the coordinates of the centers of radar images used to create electronic radar maps, and the center of the current radar image is determined by the pairing radar circular scan with PC hardware SNA, showing the position of the vessel, its coordinates, course, speed when applying the current radar image, the center of which is tied to geographic coordinates, defined by the SNA, the combination of radar images with the navigation electronic map stored on external media, geospatial information, characterized in that when the vessel is on the route of the combine on the device screen imaging radar map of the area, obtained by radar Krugovov the review and apparatus SNA with the navigation electronic map stored on external media, render the time variation of the actual depth at a fixed location area, the construction and visualization of contour largest astronomical conditions scale tidal fluctuations and surface tidal fluctuations, the height of the tide in time, determination and visualization of areas of waters for some time, where the actual depth is less than acceptable, and the representation of geospatial information on the navigation electronic map stored on an external medium, based on the mapping of points in the multidimensional space defined spatial area of the route of the vessel in the form of one-dimensional points of the line segment representing the Hilbert curve, dividing the flat the Earth's surface on a hierarchical nested squares, with each square is indexed by the code corresponding to the length of the Hilbert curve for this square, with the range of the hierarchical index is stored in the RAM storage device to external media, geospatial information, to search in a given spatial geospatial and geophysical objects are viewed on the screen of the device rendering the existing objects and determine the minimum index on the horses of the square, which entirely contains the specified spatial region, found the index to find the objects with the index equal to the index of a given spatial domain.