Method for displaying map contents of a geographical map

Abstract

The invention relates to a method for displaying map content of a geographical map (10). According to the invention, a visibility map (1) generated for a first geographical area (3) is linked as a first map type with a second map type (2) containing geodetically referenced geoobjects (13, 14) for a second geographical area (4). As a result, the geoobjects (13, 14) of the second map type (2) visible to an observer (12) are displayed as map content of the geographical map (10).

Description

[0001] The invention relates to a method for displaying map contents of a geographical map.

[0002] Geoobjects on the Earth's surface, such as rivers, roads, settlements, etc., are represented in geographical maps as a representation of reality. For some applications, it is interesting to determine viewsheds in these geographical maps, particularly based on digital elevation models in the form of raster images. For this purpose, viewsheds or lines of sight between two points can be calculated based on digital elevation models (DEMs) or other surface models.

[0003] In this context, DE10 2019 002 574 A1 discloses a navigation system and a method for discrete routing, in which a route planner calculates routes taking into account the fields of view of multiple observers in a given terrain. Preferably, routes in open terrain are determined that, if possible, do not touch any viewsheds. The fields of view are determined using grid elevation maps to identify the grid squares that should be avoided for route calculation.

[0004] Furthermore, KR 20110085107 A describes a method for analyzing geographic information using a view frequency analysis. To calculate visible grid squares of a height map, stereoscopic mechanisms are used to calculate a visual frequency table across different levels, which is used to describe the visibility of an elevation model.

[0005] The invention is based on the object of specifying a method for displaying map contents of a geographical map, in which a display of certain map contents is made possible in a simple manner with advantageous properties.

[0006] This object is achieved according to the invention by a method for displaying map contents of a geographical map having the features recited in patent claim 1.

[0007] Advantageous further developments of the method according to the invention are part of the further patent claims.

[0008] In the method according to the invention, a visibility map, in particular a geodetically referenced visibility map, is first generated in a specific first geographical area, preferably based on a height map with a specific geodetically referenced elevation profile. During this preferred generation of the visibility map from a height map, the visible pixels or grid squares of a square grid are determined, as well as the hidden or non-visible pixels or grid squares of a square grid in a raster elevation image along a line of sight from an observer point to a specific target point.This means that the visibility map is preferably generated using an algorithm that determines the visible pixels or grid squares of a square grid in a specific first geographical area by means of the gradient from geodetic distance and height difference on the basis of digital elevation models along an elevation profile.

[0009] The visibility map generated in the first geographical area, with the visibility areas determined therein based on the visible pixels or grid squares of a square grid, is then linked to another, independent second map type or map layer in a second geographical area containing geodetically referenced map content as geodetically referenced geoobjects, and is thus merged with this additional map type or map layer in the second geographical area to form a geographical map. As a result, the geodetically referenced geoobjects of the second map type are georeferenced as specific points and thus individual geoobjects and / or as specific lines and / or as specific areas and thus as individual areas in this second map type or map layer with visibility areas, and are thus indexed according to their visibility in the geographical map.

[0010] This fusion of visibility areas of the visibility map with a second map type or map layer containing specific map content to form a geographical map is performed in order to provide an observer and thus a user with environmental details in the second geographical area, preferably in order to provide an observer moving within the second geographical area and thus a user with environmental details in the second geographical area before and / or during their movement, for example on foot or in a vehicle. This is achieved in particular by providing the visible geo-objects based on any map content of the second map type or map layer in the second geographical area on a route or a travel route or in the current environment.

[0011] This means that, based on a visibility map generated for a specific first geographical area, a comparison is made with a second, independent map type or map layer for the purpose of generating a geographical map. Independent of the visibility map, this second map type preferably contains geocoordinates as geocoordinate points or geocoordinate polygons, which are then geodetically compared with the non-visible grid squares of the visibility map and the visible grid squares of the visibility map and subsequently indexed as visible or non-visible for further display.

[0012] In a preferred embodiment of the invention, the second map type is assigned the same geodetic reference system as the visibility map. This geodetic reference system can be a globally defined geodetic reference system, such as a geodetic reference system based on the Earth's ellipsoid, for example, the World Geodetic System 1984 (WGS 84) as a geodetic reference system for position information on Earth, or a geodetic reference system based on a local coordinate system with higher accuracy in smaller geographical areas, for example, the Gauss-Krüger coordinate system as a Cartesian coordinate system for representing smaller geographical areas of the Earth with metric coordinates.

[0013] The second geographical area in which the fusion of visibility areas of the visibility map with the second map type is carried out for display in the geographical map can represent a sub-area of ​​the first geographical area and thus a section of the first geographical area, or the second geographical area is selected to be the same size as the first geographical area so that these two geographical areas completely overlap.

[0014] The second map type can, in particular, contain any information and thus geoobjects that can be geodetically recorded and referenced. In particular, certain geodetically recorded and referenced geoobjects can be used for the second map type in the form of individual points, such as points of interest (POIs), or in the form of lines or waypoints, such as roads or road networks, or in the form of free-floating polygons, such as building outlines, or in the form of areas, such as for selected special areas.Thus, the latter map contents or geo-objects can be used to show the course of certain special areas such as nature reserves visible to an observer moving within the second geographical area, or to show the course of flowing waters such as rivers or streams visible to an observer moving within the second geographical area.

[0015] In a further preferred embodiment of the invention, the observer moves within the second geographical area with the aid of a vehicle's navigation system. The visible or invisible map contents or geoobjects for an observer moving within the second geographical area, and in particular for an observer navigating within the second geographical area with the aid of a vehicle's navigation system, are displayed, in particular, on a display device of the vehicle.For example, the visible or invisible areas and thus map content or geo-objects are dynamically displayed on a vehicle display during route guidance along a navigation route while the vehicle is moving, or displayed on a vehicle display before the vehicle begins its journey as part of planned route guidance along a navigation route. It can also be provided that navigation instructions for a driver are dynamically generated or selected depending on which orientation objects in the environment (e.g. a church or a traffic light or generally a POI - Point of Integrity or a traffic infrastructure element) are currently visible to the driver, e.g. as a navigation instruction: "Turn to the right behind the church in front", which assumes that the church is actually visible from the driver's position.Thus, the geoposition of the vehicle can be determined, a resulting visibility area can be determined using the method, and then a navigation assistant can select an orientation object for a navigation announcement. The navigation announcement constructed in this way can be output to the driver of the vehicle. Instead of a vehicle, this can also be done for a mobile device, such as a smartphone or AR (augmented reality) glasses.

[0016] The vehicle in which the visible or non-visible areas and thus map contents or geo-objects are displayed for an observer moving within the second geographical area can be designed as a motor vehicle or car, in particular as a passenger car, or as a truck or as a passenger bus.

[0017] With the proposed method for displaying map content of a geographical map, the areas visible or invisible to an observer within a specific geographical area for the map content or geoobjects that can be arbitrarily specified using the map layer of the second geographical map can advantageously be easily displayed. In particular, these areas visible or invisible to an observer within a specific geographical area for the map content or geoobjects that can be arbitrarily specified using the map layer of the second geographical map can advantageously be easily displayed for an observer moving within the second geographical area during the observer's movement.

[0018] The method according to the invention is used in particular in an assistance system of a vehicle, which in particular also has a display device; preferably the method according to the invention is used in a navigation system of a vehicle with a corresponding display device.

[0019] A vehicle that has at least one such assistance system is also claimed.

[0020] An exemplary embodiment of the invention is described below. It shows: Fig. 1 an elevation profile and a section of the grid squares of a geographical map for generating a visibility map, Fig. 2 an example of the map display of a geographical map based on the fusion of a visibility map with a second map type and Fig. 3 another example of the map representation of a geographical map based on the fusion of a visibility map with a second map type.

[0021] The exemplary embodiments explained below are preferred exemplary embodiments of the invention. In the exemplary embodiments, the described components each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are thus also to be considered as components of the invention, either individually or in a combination other than that shown. Furthermore, the described exemplary embodiments can also be supplemented by further features of the invention already described.

[0022] In the figures, functionally identical elements are provided with the same reference numerals.

[0023] As in the Fig. 1, a visibility map 1 is first generated in a first geographical area 3 based on an elevation profile 5 of the first geographical area 3, whereby large-scale visible areas 11 in the first geographical area 3 are determined. This topographically surface-based calculation of the visible areas 11 within the first geographical area 3 is carried out on the basis of map material that depicts the elevation profile 5 of the earth's surface and is thus geodetically referenced. For an observer position of an observer 12, and in particular for an observer 12 moving within the first geographical area 3, the respective visible areas 11 on such geodetically referenced maps in a specific geographical area 3 are accordingly determined, and likewise the respective non-visible areas 15 on such geodetically referenced maps in a specific geographical area 3 are determined.Based on these visible areas 11 and non-visible areas 15, a visibility map 1 for this geographical area 3 is generated. For this purpose, the visible pixels or visible squares 7 are calculated for the pixels or grid squares 6 of the square grid in this specific geographical area 3 by determining the gradient of visibility lines 9 along the elevation profile 5 of the pixels or grid squares 6 of a raster image 16.

[0024] According to the Fig. 2 and the Fig. 3 Subsequently, in a specific geographical area defined by latitudes φ and longitudes λ, on the basis of the visibility map 1, the visibility map 1 is merged with a second map type 2 which is available for a specific second geographical area 4 and contains geodetically referenced map contents to form a geographical map 10. As a result, the visibility of geo-objects 13, 14 in the map contents of the second map type 2 is determined in the geographical map 10 on the basis of the visible areas 11 and this is then shown as a map representation of the geographical map 10, in particular on a display device, preferably on a display device of a mobile terminal or in particular of a vehicle.

[0025] As in the Fig. 2, the second geographical area 4 of the second map type 2 corresponds to the first geographical area 3 of the visibility map 1 in its positioning, so that these two geographical areas 3, 4 have the same area boundaries defined by latitudes φ and longitudes λ and thus completely overlap for the generation of the geographical map 10.

[0026] As in the Fig. 3, the second geographical area 4 of the second map type 2 does not completely coincide with the first geographical area 3 of the visibility map 1 in its positioning, so that these two geographical areas 3, 4 do not completely overlap for the generation of the geographical map 10 and thus do not have the same area boundaries defined by latitudes φ and longitudes λ.

[0027] Based on the user-specific map contents of the second map type 2, the method according to the invention can thus offer a user, by means of an assistance system, in particular by means of an assistance system of a vehicle, environment-related information in his surroundings by means of the geographical map 10, taking into account the actual visual visibility of geo-objects 13, 14.

[0028] As particularly in the Fig. 2, using a second map type 2 containing geographical geo-objects 13, 14 in the second geographical area 6, in the geographical map 10, for example, visible points of interest can be indexed as individual geo-objects 13 or visible river courses as linear structured geo-objects 14 corresponding to the determined visible areas 11 starting from the observation point of the observer 12.

[0029] In connection with a second map type 2 containing points of interest as geo-objects 13, an assistance system as an application program, in particular an assistance system of a vehicle, can display in the geographical map 10, for example, all visible points of interest as geo-objects 13 in a surrounding area of, for example, 5 km around an observation point of the observer 12 or display in the geographical map 10 all roads and their route sections from which a specific point of interest is visible as geo-object 13.An assistance system as an application program, in particular a vehicle assistance system, can also provide an indication on the geographical map 10, for example upon entering a field of vision 11 for a sight such as a fortress or a church, as to where these points of interest are located as geo-objects 13, so that they can be viewed by an observer 12 or user. Furthermore, an assistance system as an application program, in particular a vehicle assistance system, can offer a user on the geographical map 10 locations for breaks or stopovers during a journey, taking into account the visibility of geo-objects 13. In particular, an assistance system can offer a user on the geographical map 10 locations for breaks or stopovers such locations where certain points of interest are visible as geo-objects 13.Furthermore, in the geographical map 10, the property of the visibility of points of interest as geo-objects 13 in a specific geographical area 6 can also be used in the context of guessing games. List of reference symbols 1 visibility map 2 second card type 3 first geographical area 4 second geographical area 5 Elevation profile 6 grid squares 7 visible grid squares 8 non-visible grid squares 9 lines of sight 10 geographical map 11 visible areas 12 observers 13 Geoobject POI 14 Geoobject River Course 15 non-visible areas 16 Raster image φ latitude λ longitude QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 002 574 A1

[0003] KR 20110085107 A

[0004]

Claims

[1] Method for displaying map contents of a geographical map (10), characterized by that a visibility map (1) generated for a first geographical area (3) as a first map type is linked to a second map type (2) containing geodetically referenced geoobjects (13, 14) for a second geographical area (4) in such a way that the geoobjects (13, 14) of the second map type (2) visible to an observer (12) are displayed as map content of the geographical map (10). [2] Method according to claim 1, characterized by that the geo-objects (13, 14) of the second map type (2) visible to an observer (12) moving within the second geographical area (4) are dynamically displayed as map content of the geographical map (10). [3] Method according to claim 1 or 2, characterized bythat the second geographical area (4) is formed by a sub-area of ​​the first geographical area (3), or that the second geographical area (4) is formed in accordance with the first geographical area (3). [4] Method according to one of claims 1 to 3, characterized by that certain geographical points (13) and / or certain geographical lines (14) and / or certain geographical areas are used as geodetically referenced geoobjects (13, 14) of the second map type (2). [5] Method according to one of claims 1 to 4, characterized by that the geo-objects (13, 14) of the second map type (2) visible to an observer (12) moving within the second geographical area (4) by means of a vehicle are displayed on a display device of the vehicle while the vehicle is traveling. [6] Method according to claim 5, characterized bythat the geo-objects (13, 14) of the second map type (2) visible to an observer (12) moving within the second geographical area (4) by means of a vehicle are displayed on a display device of the vehicle while the vehicle is traveling as part of a route guidance by means of a navigation system. [7] Method according to claim 5, characterized by that the visible geo-objects (13, 14) within the second geographical area (4) are displayed on a display device of the vehicle by means of a navigation system before the vehicle travels as part of a planned route guidance. [8] Method according to one of claims 1 to 7, characterized bythat the visibility map (1) for the first geographical area (3) as the first map type is generated using an elevation profile (5) of a geodetic reference system by means of the gradients of the elevation profile (5) along an elevation map of a geodetic reference system. [9] Assistance system of a vehicle in which a method according to one of claims 1 to 8 is applied. [10] Vehicle with an assistance system according to claim 9.

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