CN114490902B

CN114490902B - Multi-dimensional space self-adaptive subdivision and coding method and system for two-dimensional geographic entity

Info

Publication number: CN114490902B
Application number: CN202210012415.5A
Authority: CN
Inventors: 林鸿; 胡耀锋; 张鹏程; 邓兴栋; 何华贵; 丘广新; 吴健华
Original assignee: Guangzhou Urban Planning Survey and Design Institute
Current assignee: Guangzhou Urban Planning Survey and Design Institute
Priority date: 2022-01-06
Filing date: 2022-01-06
Publication date: 2023-03-24
Anticipated expiration: 2042-01-06
Also published as: CN114490902A

Abstract

The invention provides a multi-dimensional space self-adaptive subdivision and coding method and a system of a two-dimensional geographic entity, wherein the method comprises the following steps: formulating a space position coding rule of the two-dimensional geographic entity; determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; determining a space subdivision mode corresponding to the space type according to the space type; and coding the two-dimensional geographic entity according to the space type and the space position coding rule. The method establishes a spatial position coding rule for each type of two-dimensional geographic entity, and can automatically calculate the spatial position coding of each type of two-dimensional geographic entity by using a derived formula; through space position coding, the multi-dimensional subdivision grid where the two-dimensional geographic entity is located can be quickly positioned.

Description

Multi-dimensional space self-adaptive subdivision and coding method and system for two-dimensional geographic entity

Technical Field

The invention relates to the technical field of surveying and mapping, in particular to a multidimensional space self-adaptive subdivision and coding method and system for a two-dimensional geographic entity.

Background

Novel basic survey and drawing is the important support of new capital construction of country, novel wisdom city construction. The novel basic mapping is inherited and developed for the traditional basic mapping, compared with the traditional basic mapping, the novel basic mapping has the characteristics of global coverage, sea and land consideration, linkage updating, on-demand service, open sharing and the like, is an early-stage, basic and public utility, is widely applied to the aspects of natural resources, environmental protection, emergency disaster relief, urban management and the like, and plays the roles of basic, security and foreignness in promoting high-quality development of various industries.

At present, a two-dimensional geographic entity space subdivision and coding method mainly comprises the following steps:

(1) According to the topographic map: taking 1; (2) according to coordinate values: taking coordinates of the geographic entity feature points or the geometric centers as space codes; (3) dividing according to administration: administrative division codes such as districts (counties), streets (towns) and the like are used as spatial codes; (4) geographic grid according to longitude and latitude: the earth surface is spatially divided according to 10 levels such as world level, national level, regional level, provincial level, city level, county level, street (county) level, community (village) level, functional unit level, geographic entity level and the like, the geographic entity code consists of four parts of grid unit code, basic code, integral code and minute-second code, the center point of the geographic entity falls into a certain geographic grid, and the code of the geographic grid is taken for the geographic entity; (5) Beidou grid position codes: the grid position code which is developed on the basis of the earth space subdivision theory and is suitable for being output by various application terminals of the Beidou satellite navigation system comprises a Beidou two-dimensional grid position code, a Beidou three-dimensional grid position code, a Beidou reference grid position code, a Beidou short position code and the like. And (6) other subdivision and coding methods.

However, the existing space subdivision coding method is only suitable for certain two-dimensional geographic entities, and no two-dimensional geographic entity space position coding which can automatically adapt to the types of planes, heights, planes plus heights and the like exists. The two-dimensional geographic terrain spatial subdivision and coding mainly takes a two-dimensional form as a main defect, and the two-dimensional geographic terrain spatial subdivision and coding mainly has the following steps:

(1) According to the topographic map. (1) Two-dimensional form, no height information; (2) representing the location of the entire geographic entity with one point at the center (or centroid) of the geographic entity, without indicating the integrity of the entire geographic solid; (3) independent coordinate systems are established in most cities in China, the used picture numbers are not nationwide unified, so that national and even global unification is not facilitated, and the position codes have no universality; (4) is not beneficial to large-scale geographic entity coding, such as Zhujiang, yangtze and Jingzhu high speed;

(2) By coordinate value. (1) The position of the whole geographic entity is represented by a geographic entity characteristic point or a center (or a centroid), and the integrity of the whole geographic entity is not represented; (2) the coordinate systems used in various places are not uniform, the coordinate values are different, and the position codes have no universality; (3) is not beneficial to large-scale geographic entity coding, such as Zhujiang, yangtze river and Jingzhu high speed;

(3) And (4) dividing by administrative divisions. (1) Two-dimensional form, no height information; (2) administrative divisions may be adjusted, resulting in that the geo-entity code is not unique after adjustment; (3) large-scale geographic entities may span multiple administrative divisions, such as Zhujiang, yangtze and Jingzhu, and cannot be brought into an administrative division code;

(4) According to longitude and latitude. (1) Two-dimensional form, no height information; (2) influence of a geographic entity range on the longitude and latitude grids is not considered, and geographic entities spanning the longitude and latitude grids are difficult to process; (3) the longitude and latitude grids do not have nesting, so that the calculation, the positioning and the searching are inconvenient to be carried out quickly;

(5) Beidou grid position codes: (1) plane + height form, not adopted 2 ⁿ Subdivision, plane and height coding are complex to calculate; (2) the level of plane and height coding is not continuous; (3) in the plane grids, the 9 th level is approximately equal to 12.0cm multiplied by 12.0cm grids at the equator of the earth, the 10 th level is approximately equal to 1.5cm multiplied by 1.5cm grids at the equator of the earth, most of China is in medium and high latitude, the length of the geographical grids is smaller, and the grids are not suitable for granularity expression of most geographical entities; (4) in the height grid, level 9 and level 10 are also not applicable to most geographic entity granularity expressions; (5) at present, each city is applicable to normal height, the standard adopts geodetic height, and height coding cannot be directly carried out;

(6) Other encoding methods. Mainly takes a certain type of two-dimensional geographic entity codes as a main code, and cannot be automatically suitable for all types of two-dimensional geographic entity codes.

Disclosure of Invention

In order to solve the above prior art problems, the invention provides a multi-dimensional space self-adaptive subdivision and coding method and system for two-dimensional geographic entities, wherein a space position coding rule is formulated for each type of two-dimensional geographic entity, and the space position coding of each type of two-dimensional geographic entity can be automatically calculated by using a derivation formula; through space position coding, the multi-dimensional subdivision grid where the two-dimensional geographic entity is located can be quickly positioned.

The invention provides a multi-dimensional space self-adaptive subdivision and coding method of a two-dimensional geographic entity, which comprises the following steps:

formulating a space position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity encoding length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional encoding combination rule;

determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space type includes: a plane type, a height type, and a plane + height type;

determining a space subdivision mode corresponding to the space type according to the space type; wherein, the subdivision mode comprises: plane subdivision, height subdivision and plane + height subdivision;

and coding the two-dimensional geographic entity according to the space type and the space position coding rule.

Further, the determining a space subdivision mode corresponding to the space type according to the space type includes:

if the space type is a plane type, dividing the two-dimensional geographic entity by adopting plane division;

if the space type is a height type, subdividing the two-dimensional geographic entity by adopting height subdivision;

and if the space type is a plane + height type, subdividing the two-dimensional geographic entity by adopting plane + height subdivision.

Further, the subdividing the two-dimensional geographic entity by adopting a plane subdivision includes:

performing plane projection on the earth surface from the equator and the original meridian to establish a plane basic grid;

the longitude is extended from-180 degrees to-256 degrees, the latitude is extended from-90 degrees to-256 degrees to form a square of 512 degrees multiplied by 512 degrees as a 0-level plane grid;

performing quadtree segmentation on the 0-level planar grid to form 4 planar sub-grids serving as 1-level planar grids;

performing quadtree segmentation on the level 1 planar grid to form 4 planar sub-grids serving as level 2 planar grids;

and sequentially recursing to form n-level plane grids, wherein n is more than or equal to 1 and less than or equal to 32.

Further, the subdividing the two-dimensional geographic entity by adopting the height subdivision includes:

establishing a height basic grid in a space range from the geocenter to 56996km above the earth surface as a 0-level height grid;

performing binary tree segmentation on the 0-level mesh to form 2 height sub-meshes serving as the 1-level mesh;

performing binary tree segmentation on the level-1 mesh to form 2 height sub-meshes serving as the level-2 mesh;

and sequentially recursing to form m-level grids, wherein m is more than or equal to 1 and less than or equal to 32.

Further, the subdividing the two-dimensional geographic entity by using the plane + height subdivision includes:

recursion is carried out in sequence to form n-level plane grids, wherein n is more than or equal to 1 and less than or equal to 32;

performing binary tree segmentation on the 0-level grid to form 2 height sub-grids serving as 1-level grid;

Further, the encoding the two-dimensional geographic entity according to the spatial type and the spatial position encoding rule includes:

if the space type is a plane type, encoding the two-dimensional geographic entity by adopting a plane code;

if the space type is a height type, encoding the two-dimensional geographic entity by adopting a height code;

and if the space type is a plane + height type, encoding the two-dimensional geographic entity by adopting a plane + height code.

Further, the encoding the two-dimensional geographic entity by using a flat code includes:

determining the level of a plane grid corresponding to the two-dimensional geographic entity;

obtaining the spatial position code of the circumscribed rectangle of the two-dimensional geographic entity in n-level planar grids through iterative computation, wherein n is more than or equal to 1 and less than or equal to 32;

comparing the spatial position codes of the angular points of the two-dimensional geographic entity;

if the spatial position codes of all the angular points of the two-dimensional geographic entity in each level of plane grid are the same, the spatial position code of the two-dimensional geographic entity is the position code of any angular point;

if the spatial position codes of all the angular points of the two-dimensional geographic entity in the plane grids of the designated level are different, whether the upper-level grid codes are the same or not is calculated, if the upper-level grid codes are the same, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and the two-dimensional geographic entity is sequentially traversed until the spatial position codes of all the angular points are found to be the same.

Further, the encoding the two-dimensional geographic entity with altitude encoding includes:

determining the level of a height grid corresponding to the two-dimensional geographic entity;

obtaining the height position codes of the highest point and the lowest point of the two-dimensional geographic entity in m-level plane grids respectively through iterative calculation, wherein m is more than or equal to 1 and less than or equal to 32;

if the spatial position codes of the highest point and the lowest point of the two-dimensional geographic entity at each level of the height grid are the same, the spatial position code of the two-dimensional geographic entity is the position code of any one angular point;

if the spatial position codes of the height grids of the highest point and the lowest point of the two-dimensional geographic entity at the designated level are different, whether the upper-level grid codes are the same or not is calculated, if the spatial position codes of the two-dimensional geographic entity at the designated level are the same, the spatial position codes of the two-dimensional geographic entity at the designated level are the grid codes of the level, and the two-dimensional geographic entity is sequentially traversed until the spatial position codes of the highest point and the lowest point are found to be the same.

Further, the encoding the two-dimensional geographic entity by using plane + altitude encoding includes:

determining the level of a plane + height grid corresponding to the two-dimensional geographic entity;

obtaining the spatial position codes of the circumscribed rectangles and the elevation extreme points of the two-dimensional geographic entity in the n-level plane + height grid through iterative calculation, wherein n is more than or equal to 1 and less than or equal to 32;

comparing the plane + height spatial position codes of each corner point of the two-dimensional geographic entity;

if the spatial position codes of all the angular points of the two-dimensional geographic entity in each level of grid are the same, the spatial position code of the two-dimensional geographic entity is the position code of any angular point;

if the spatial position codes of all the angular points of the two-dimensional geographic entity in the grids at the designated level are different, calculating whether the upper-level grid codes are the same or not, if so, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and sequentially traversing until the spatial position codes of all the angular points are found to be the same;

the second aspect of the present invention provides a multidimensional space adaptive partitioning and encoding system for a two-dimensional geographic entity, comprising:

the spatial position coding rule making module is used for making a spatial position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity coding length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional coding combination rule;

the space type determining module is used for determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space types include: a plane type, a height type, and a plane + height type;

the space subdivision module is used for determining a space subdivision mode corresponding to the space type according to the space type; wherein, the subdivision mode comprises: plane subdivision, height subdivision and plane + height subdivision;

and the spatial position coding module is used for coding the two-dimensional geographic entity according to the spatial type and the spatial position coding rule.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

the invention provides a multi-dimensional space self-adaptive subdivision and coding method and a system of a two-dimensional geographic entity, wherein the method comprises the following steps: formulating a space position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity coding length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional coding combination rule; determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space type includes: a plane type, a height type, and a plane + height type; determining a space subdivision mode corresponding to the space type according to the space type; wherein, the subdivision mode comprises: plane subdivision, height subdivision and plane + height subdivision; and coding the two-dimensional geographic entity according to the space type and the space position coding rule.

Aiming at multi-type two-dimensional geographic entities, the invention designs a multi-dimensional space subdivision and space coding method, which has the advantages that:

(1) Global uniqueness of the subdivision grid: the earth is spatially divided by adopting a plane, a height and a combination of the plane and the height, grids are not overlapped and crossed, and the grids have global uniqueness;

(2) Three-dimensional full coverage: each grade of grid seamlessly covers the whole earth from the center of the earth to a region about 56996km above the surface of the earth;

(3) Nesting: mesh subdivision is performed according to hierarchy recursion, and meshes of different levels have nesting;

(4) Expression integrity: two-dimensional geographic entities of different types and sizes can be completely accommodated in grids of different types and different levels;

(5) Calculability: knowing a two-dimensional geographic entity, calculating a spatial position code of the two-dimensional geographic entity; knowing the space position code, calculating a two-dimensional grid;

(6) Rapidness: the whole earth is divided into planes and heights according to 2n, so that quick indexing, calculation and processing of a computer are facilitated;

(7) The practicability is as follows: the method covers the expression of two-dimensional geographic entities with different types and ranges from meter level, decimeter level to centimeter level.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flowchart of a multidimensional space adaptive partitioning and encoding method for a two-dimensional geographic entity according to an embodiment of the present invention;

fig. 2 is a flowchart of a multidimensional space adaptive partitioning and encoding method for a two-dimensional geographic entity according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of a flat coding structure according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a height coding structure provided by an embodiment of the present invention;

FIG. 5 is a diagram illustrating a plane + height encoding structure according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of level 1 planar meshing provided by an embodiment of the present invention;

fig. 7 is a schematic diagram of level 2 planar meshing provided by an embodiment of the present invention;

FIG. 8 is a diagram of level 1 meshing provided by an embodiment of the present invention;

FIG. 9 is a diagram of a level 2 meshing provided by an embodiment of the present invention;

FIG. 10 is a diagram of an apparatus of a multidimensional space adaptive partitioning and encoding system for a two-dimensional geographic entity according to an embodiment of the present invention;

fig. 11 is a block diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be understood that the step numbers used herein are for convenience of description only and are not intended as limitations on the order in which the steps are performed.

It is to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The term "and/or" refers to and includes any and all possible combinations of one or more of the associated listed items.

A first aspect.

Referring to fig. 1, an embodiment of the present invention provides a method for multi-dimensional space adaptive partitioning and encoding of a two-dimensional geographic entity, including:

s10, formulating a space position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity code length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional code combination rule.

S20, determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space type includes: a plane type, a height type, and a plane + height type.

S30, determining a space subdivision mode corresponding to the space type according to the space type; wherein, the subdivision mode comprises: plane subdivision, height subdivision and plane + height subdivision.

And S40, coding the two-dimensional geographic entity according to the space type and the space position coding rule.

Preferably, the determining a space subdivision mode corresponding to the space type according to the space type includes:

if the space type is a height type, dividing the two-dimensional geographic entity by adopting height division;

Preferably, the subdividing the two-dimensional geographic entity by using plane subdivision includes:

performing plane projection on the earth surface from the equator and the primary meridian to establish a plane basic grid;

Preferably, the subdividing the two-dimensional geographic entity by using the height subdivision includes:

Preferably, the subdividing the two-dimensional geographic entity by using the plane + height subdivision includes:

establishing a height basic grid in a space range of 56996km from the center of the earth to the ground surface as a 0-level height grid;

Preferably, the encoding the two-dimensional geographic entity according to the spatial type and the spatial position encoding rule includes:

Preferably, the encoding the two-dimensional geographic entity by using a flat code includes:

Preferably, the encoding the two-dimensional geographic entity by using altitude encoding includes:

if the spatial position codes of the highest point and the lowest point of the two-dimensional geographic entity in each level grid are the same, the spatial position code of the two-dimensional geographic entity is the position code of any one angular point;

Preferably, the encoding the two-dimensional geographic entity by using plane + altitude encoding includes:

if the spatial position codes of all the angular points of the two-dimensional geographic entity in the plane grids of the designated level are different, calculating whether the upper-level grid codes are the same or not, if so, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and sequentially traversing until the spatial position codes of all the angular points are found to be the same;

the method provided by the invention sets a spatial position coding rule for each type of two-dimensional geographic entity, and can automatically calculate the spatial position coding of each type of two-dimensional geographic entity by using a derived formula; through space position coding, the multi-dimensional subdivision grid where the two-dimensional geographic entity is located can be quickly positioned.

Referring to fig. 2, in another embodiment of the present invention, the present invention provides a method for multi-dimensional space adaptive partitioning and encoding of a two-dimensional geographic entity, including: two-dimensional geographic entity space position coding rules (step 1-3), through two-dimensional geographic entity space type judgment and range determination (step 5-7, step 17-19), an adaptive space subdivision scheme is designed (earth plane four-fork recursion subdivision < step 8-12 >, height two-fork recursion space subdivision < step 20-23 >, plane + height subdivision < step 8-12, step 20-23 >), two-dimensional geographic entity plane coding (step 13-16, step 28-29), height coding (step 24-29), plane + height coding (step 13-16, step 24-29) are determined by calculating two-dimensional geographic entity plane range and height range, and the detailed description is as follows:

1. determining the type and range of a two-dimensional geographic terrain:

step 1: and formulating an entity coding length rule. And aiming at different storage and management requirements, the two-dimensional geographic entity coding can be carried out by adopting a fixed-length coding mode or an indefinite-length coding mode.

Step 2: and formulating a two-dimensional entity grid level rule. And according to the maximum granularity and the minimum granularity of the two-dimensional geographic entity, designating the maximum and minimum levels of the mesh subdivision for encoding the two-dimensional geographic entity.

And 3, step 3: and formulating a two-dimensional entity multi-dimensional coding combination rule. Different coding combination rules are formulated for different types of geographic entities. If the geographic entity has only plane coordinates (type 1), the trellis-coded structure is shown in fig. 3; if the two-dimensional geographic entity only has an elevation coordinate (type 2), the grid coding structure is shown as 4; if the two-dimensional geographic entity has both planar and elevational coordinates (type 3), its trellis-coded structure is shown in fig. 5.

2. Judging the type and determining the range of the two-dimensional geographic terrain space:

and 4, step 4: and judging the type of the two-dimensional geographic entity. According to the space type of the two-dimensional geographic entity, the two-dimensional geographic entity is divided into three categories, namely a plane coordinate only, a height coordinate only and a plane + height coordinate.

There are different types of two-dimensional geographic entities that require different grid storage. Therefore, the mesh generation type and the mesh hierarchy are determined according to the type and the range of the two-dimensional geographic entity. The processing flows of three types of two-dimensional geographic entities, namely a plane type (steps 5 to 7), an altitude type (steps 17 to 19) and a plane + altitude type (steps 5 to 7 and steps 17 to 19), are respectively described below.

1. Type 1: planar range:

the planar range of the geographic entity needs to be determined, and the process is as follows:

and 5: and determining a plane coordinate extreme value of the two-dimensional geographic entity. And respectively sequencing the point sets of the two-dimensional geography according to plane coordinates (X and Y), and determining the maximum value and the minimum value of the X coordinate and the Y coordinate, thereby determining the distribution range of the two-dimensional geography entity in the X direction and the Y direction.

Step 6: and generating a plane minimum bounding rectangle. And generating the minimum bounding rectangle of the plane according to the extreme value of the geographic entity. If the point is a single point, the plane coordinates (X, Y) of the point are directly used.

And 7: and calculating the longest edge Lc of the minimum bounding rectangle of the plane for subsequent determination of the hierarchical grid.

2. Type 2: height range:

the altitude range of the geographic entity needs to be determined, and the process is as follows:

and step 17: and determining a two-dimensional geographic entity height coordinate extreme value. Respectively sorting the two-dimensional geographic entity point sets according to the elevation h, and calculating the minimum value (h) of the elevation _min ) Maximum value (h) _max ) And height difference (h) _c ) And determining the elevation range of the two-dimensional geographic entity.

Step 18: calculating the geodetic height D _min 、D _max . The normal height h is obtained by using the data of plane coordinate transformation procedure and approximate ground level _min 、h _max To ground height D _min 、D _max 。

Step 19: and calculating the distance (in degrees) from the highest point and the lowest point of the two-dimensional geographic entity to the geocenter. Converting Guangzhou 2000 coordinates (X, Y) of two-dimensional geographic entity corner point into CGCS2000 longitude and latitude coordinates (Lat, lng), and measuring geodetic height (such as D) _min ) Calculating the distance from the center of the sphere to the point according to the formulas (1) to (6)(Eh) determining its spatial position in the highly subdivided grid.

e ² ＝(a ² -b ² )/a ² …………………………(1)；

X＝(N+D _min )cosLatcosLng……………………………(3)；

Y＝(N+D _min )cosLatsinLng……………………………(4)；

Z＝(N(1-e ² )+D _min )sinLat……………………………(5)；

In the formula:

a-the major semi-axis of CGCS2000 ellipsoid, value is 6378137;

b-the minor semi-axis of the CGCS2000 ellipsoid, value 6356752.3141;

e-the first eccentricity of the Earth;

n-curvature radius of earth-unitary mortise;

x, Y, Z-is the spatial rectangular coordinate of the entity range.

3. Type 3 (plane + height):

for a two-dimensional geographic entity with a plane and an elevation, a plane range and an elevation range need to be calculated, and steps 5-7 and steps 17-19 are performed.

3. Designing an adaptive space subdivision scheme:

different space subdivision modes are adopted for different two-dimensional geographic entity types, namely plane subdivision, height subdivision and plane + height subdivision.

1. Carrying out plane subdivision;

the geographic entities of type 1 (plane) only adopt plane subdivision, and the following is a plane subdivision process (steps 8-12).

And 8: and (4) sphere transformation. And performing plane projection on the earth surface from the equator and the meridian of the original meridian to establish a plane basic grid.

And step 9: and the longitude and latitude ranges are expanded. For the establishment of subsequent mesh subdivision, the longitude is extended from-180 degrees to-256 degrees, the latitude is extended from-90 degrees to-256 degrees to form a square of 512 degrees multiplied by 512 degrees as a 0-level plane mesh.

Step 10: and establishing a level 1 planar subdivision grid. And performing four-fork subdivision on the basis of the 0-level mesh to form 4 plane sub-meshes. The two-dimensional plane grid codes respectively represent southwest hemisphere, southeast hemisphere, northwest hemisphere and northeast hemisphere by G0, G1, G2 and G3.

Step 11: and establishing a 2 nd level plane subdivision grid. And performing four-fork subdivision on the basis of the 1 st-level mesh to form 4 plane sub-meshes. The two-dimensional plane grids are respectively coded by 0, 1, 2 and 3 according to the Z shape.

Step 12: and recursively establishing the nth level planar subdivision grid. The nth level grids are all divided according to a binary tree on the basis of the last level grids to form 4 sub-grids which are respectively coded according to a Z shape by 0, 1, 2 and 3. And repeating the steps, continuously subdividing the grids, and establishing grids of different layers. In order to facilitate the quadtree subdivision, 1 ° × 1 ° is divided into 64'× 64', that is, the grid size of the 9 th-level grid is expanded from 1 ° × 1 ° to 64'× 64'; the 1 'x 1' is divided into 64 "x 64", i.e., the grid size of the level 15 grid is expanded from 1 'x 1' to 64 "x 64".

2. Highly subdividing:

type 2 (altitude) geographic entities employ only altitude partitioning, described below as an altitude partitioning procedure (steps 20-23).

Step 20: the height is expanded to 0-512 degrees. The spatial range from the center of the earth to about 56996km above the earth establishes a height basic grid, namely a 0-level height grid, and 1 degree is about 111.32km.

Step 21: and establishing a 1 st level subdivision grid. On the basis of the 0-level grid, binary division is carried out to form 2 sub-grids. The height ranges of 0-256 degrees and 256-512 degrees are respectively represented by G4 and G5 codes.

Step 22: and establishing a 2 nd level subdivision grid. On the basis of the 1 st level mesh, binary division is carried out to form 2 sub meshes, and encoding is carried out by 4 and 5 from low to high respectively.

Step 23: and recursively establishing the nth-level subdivision grid. The nth stage of grids are subjected to binary division on the basis of the last stage of grids to form 2 sub-grids, and the sub-grids are respectively coded by 4 and 5 from low to high. And iterating in this way, continuously subdividing the grids, and establishing grids of different layers. The space from the center of the earth to about 56996km above the earth surface of the whole earth is divided into a 0-32 level hierarchical grid system, and a regular reference frame is established for the height position of the two-dimensional geographic entity.

3. Plane + height subdivision:

and (3) for the two-dimensional geographic entity with the plane and the elevation, dividing the plane and the elevation, and performing steps 8-12 and steps 20-23.

4. Calculating the spatial position code of the two-dimensional geographic entity:

1. plane coding:

the type 1 (plane) two-dimensional geographic entity performs plane coding, and the following is a plane coding process (steps 13 to 16 and steps 28 to 29).

Step 13: determining a plane level grid to which the two-dimensional geographic entity is closest. And comparing the size of Lc with the grid size of each level, and selecting the closest grid in the grid levels larger than Lc as the grid level where the two-dimensional geographic entity is located in each level of grid.

Step 14: and calculating the code of the minimum circumscribed rectangle corner point of the two-dimensional geographic entity plane in the level 1 plane grid. And determining the position of the minimum circumscribed rectangle in the 1 st-level grid according to the longitude and latitude coordinates of 4 corner points of the minimum circumscribed rectangle and the longitude and latitude coordinates (0 degrees and 0 degrees) of the positioning corner points of the 0-level grid.

Step 15: and calculating the code of the minimum circumscribed rectangle corner point of the two-dimensional geographic entity plane in the 2 nd-level plane grid. According to the latitude and longitude of the positioning corner point (grid southwest corner) of the 1 st level grid

And the warp difference or weft difference of the 2 nd mesh(Δ _i λ), determining a planar position code of the two-dimensional geographic entity in the grid of the current level according to the equations (7) - (8) and the table 1.

Wherein the difference in warp or weft (Δ) _i λ) is as follows:

in the formula,. DELTA. _i And lambda is the weft difference or warp difference of the ith-level two-dimensional grid.

When i-1 >:

λ _i-1 ＝ _i-2 +(a _i-1 -1)×Δ _i-1 λ…………(10)；

in the formula:

λ _i -the location corner longitude of the i-th level two-dimensional grid where the location is located;

-the location corner latitude of the i-th level two-dimensional grid where the position is located;

a _i column number of the two-dimensional grid at level i for this position;

b _i row number for the location in the ith level two-dimensional grid.

TABLE 1 correspondence table of plane grid rows and columns and plane position codes

a _L	b _L	Trellis coding
			1	1	0
2	1	1
			1	2	2
2	2	3

Step 16: and recursively calculating the nth-level spatial plane trellis coding. And repeating the step 15, and performing iterative calculation until the nth-level spatial position code of the two-dimensional geographic entity corner point is obtained.

Step 28: and comparing the spatial position codes of the corner points of the two-dimensional geographic entity. If the spatial position codes of the angular points at the nth level are the same, the spatial position code of the two-dimensional geographic entity is the position code of any angular point; if the spatial position codes of the individual angular points are different, the angular points are not in the grids of the same level, whether the grid codes of the upper level (parent level) are the same or not is calculated, if the grid codes of the upper level (parent level) are the same, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and the two-dimensional geographic entity is sequentially traversed until the spatial position codes of all the angular points are found to be the same.

Step 29: and generating a two-dimensional geographic entity space position code.

2. And (3) height coding:

type 2 (altitude) geographic entities employ only altitude partitioning, described below as an altitude partitioning procedure (steps 24-29).

Step 24: a closest height level grid of the two-dimensional geographic entity is determined. Comparison h _c The size of each layer of grid is selected to be larger than h _c The nearest grid in the grid hierarchy of (2) is used as the grid hierarchy where the two-dimensional geographic entity is located.

Step 25: and calculating the codes of the highest point and the lowest point of the two-dimensional geographic entity in the level 1 grid. And calculating the height position code of the angular point of the geographic entity in the level 1 grid according to the distance (Eh) from the two-dimensional geographic entity to the center of the sphere and the positioning height (256 degrees) of the level 1 grid.

Step 26: and calculating the codes of the highest points and the lowest points of the two-dimensional geographic entities in the level 2 grid. Height of location corner point (H) according to i-1 level grid _i-1 ) And the height difference (delta) of the current stage grid _i H) The altitude location code of the two-dimensional geographic entity is determined according to equations (12) - (13) and table 2.

When i-1 >:

H _i-1 ＝H _i-2 +(c _i-1 -1)×Δ _i-1 H………………(13)；

in the formula (I), the compound is shown in the specification,

H _i -the height of the location corner point of the i-th level two-dimensional grid where this position is located;

c _i -the column number of the location in the i-th level two-dimensional grid;

Δ _i h-height difference of i-th level two-dimensional grid, and Δ _i λ is equal.

Table 2 table of correspondence between height grid numerical values and height position codes

h _L	Trellis coding
		1	4
2	5

Step 27: and recursively calculating the nth level space height grid coding. And repeating the step 26, and performing iterative calculation until the nth level spatial height position code of the two-dimensional geographic entity corner point is obtained.

Steps 28-29 are similar to those described above and will not be described further herein.

3. Plane + height coding:

for the type 3 two-dimensional geographic entity, the plane and the height of the corner point both need to be coded, and the steps 13 to 16 and the steps 24 to 27 are carried out. After comparing the corner planes + the altitude codes (step 28), a two-dimensional geo-physical spatial code is determined (step 29).

(1) Global uniqueness of the subdivision grid: the earth is spatially subdivided by adopting a combination form of plane, height and plane plus height, grids are not overlapped and crossed, and have global uniqueness;

(2) Three-dimensional full coverage: each grade of grid seamlessly covers the whole earth and a region from the center of the earth to about 56996km above the surface of the earth;

(3) Nesting: mesh subdivision is carried out according to hierarchy recursion, and meshes of different levels have nesting;

(6) Rapidness: the whole earth is according to 2 ⁿ The plane and height subdivision is carried out, so that the quick indexing, calculation and processing of a computer are facilitated;

Taking the cantonese tower as an example, the cantonese tower, a two-dimensional geographic entity, contains multiple points. The coordinate of Guangzhou 2000 as its central point is (227000.312, 43642.322), the Guangzhou elevation is 8.66, the tower height is 600 m, and the space position coding method is explained in three types:

1. two-dimensional geographic entity (planar type):

(1) Searching a point set of the Guangzhou tower combined geographic entity, and calculating 4 minimum circumscribed rectangles, such as (226907.021, 43584.034), (226907.021, 43727.034), (227050.021, 43584.034); and the side length was calculated to be 143 meters, and the closest is the 19 th order (length is 217 meters).

(2) The closest grid level greater than the longest side of the minimum bounding rectangle is chosen, with level 19 (217.42 m × 217.42 m) being used in this example, accommodating and closest to the Guangzhou tower (143 m).

(3) And respectively calculating the two-dimensional grid position codes of the 4 corner points of the circumscribed rectangle in the 19 th-level grid according to the rules. The four corner points are converted into CGCS2000 latitude and longitude (23.062972116 °,113.190662916 °), (23.062972037 °,113.191165452 °), (23.063436887 °,113.191165539 °), (23.06343696 °,113.190662999 °), using a coordinate conversion program. In the following, (23.062972116 °,113.190662916 °) will be exemplified.

(4) Level 1 planar grid position code calculation: the position of the point is located in a northeast hemisphere, the 1 st-level two-dimensional grid position code is G3, the longitude and latitude of the positioning angular point are (0 degrees ), and the 1 st-level code is G3. As shown in fig. 6.

(5) Level 2 planar grid position code calculation: firstly, obtaining the longitude and latitude coordinates lambda of the positioning corner point of the 1 st level grid of the position ₁ ＝0°,

The level 2 two-dimensional grid has a weft or warp difference of 128. According to the equations (7) to (11), the calculation is as follows. And looking up a table 1 to obtain a 2 nd-level two-dimensional grid position code G30. As shown in fig. 7.

(6) And recursively calculating the plane grid position codes of the point in the 3-19 level grids.

(7) The planar grid position codes for the 4 corner points are compared. If the position codes of the plane grids of the 4 angular points are the same, the external rectangles are shown to be in the same plane grid, and the grid position code is the position code of any angular point; if the planar grid position codes of the individual angular points are different, the angular points are not in the same grid, the grid at the upper level needs to be considered, if the planar grid position codes of the individual angular points are all in the upper level (such as 18 levels), the two-dimensional grid position codes are 18-level grid codes, and the two-dimensional grid position codes are sequentially traversed until the spatial position codes of all the angular points are the same.

2. Two-dimensional geographic entity (height type):

(1) And searching a point set of the Guangzhou tower combined geographic entity, calculating an elevation range, such as-2.008 to-2.015, and calculating height grid codes of the highest point and the lowest point respectively. In the following, (23.062972116 °,113.190662916 °, -2.008) is taken as an example, assuming that 19 th-level grid (217.42 m × 217.42 m) storage is adopted.

(2) According to the expressions (6) to (11), the height of the point from the geocentric is 57.1533 degrees through conversion calculation.

(3) Level 1 trellis location code: the height of the 0 th-level locating corner point is 0 degrees, the height difference of the 1 st-level grid is 256 degrees, and the height position code is calculated to be 4 according to the formula (12) and the table 2. The level 1 trellis position code is G4. As shown in fig. 8.

(4) Level 2 trellis location code: the height of the 1 st-level locating corner point is 0 degree, the height difference of the 2 nd-level two-dimensional grid is 128 degrees, the height position code is calculated to be 4 according to the formulas (12) - (13) and the table 2, and the position code of the 2 nd-level plane + height grid is G44. As shown in fig. 9.

(5) And recursively calculating to a specified level grid, and acquiring the height grid position code of the point.

(6) The height grid position codes of the corner points are compared. If the height grid position codes of all the angular points are the same, the external rectangles are shown to be in the same height grid, and the grid position code is the position code of any angular point; if the height grid position codes of the individual corner points are different, the corner points are not in the same grid, the grid at the upper level needs to be considered, if the height grid position codes of all the corner points are in the upper level (such as 18 levels), the two-dimensional grid position codes are 18-level grid codes, and the two-dimensional grid position codes are sequentially traversed until the height position codes of all the corner points are the same.

3. Two-dimensional geographic entity (plane + altitude type):

(1) Searching a point set of the Guangzhou tower combined geographic entity, calculating the range of plane and elevation coordinates, selecting the nearest hierarchical grid, and respectively calculating the plane + height grid position code of each angular point to the specified hierarchical grid. Taking the corner points (23.062972116 °,113.190662916 °, -2.008) as an example, the 19 th-level grid (217.42 m × 217.42 m) is used for storage.

(2) Level 1 plane + height grid position code calculation. According to the above example, it can be known that if the dot level 1 plane grid position code is G3 and the level 1 grid position code is G4, the dot level 1 plane + height position code is G34.

(3) Level 2 plane + height grid position code calculation. According to the above example, it can be known that if the dot level 2 plane grid position code is 0 and the level 1 grid position code is 4, the dot level 2 plane + height position code is G3404.

(4) And recursively calculating to the plane position code and the height position code of the appointed level to obtain the grid position code of the point.

(5) Comparing the plane of each angular point and the height position code, and if the grid position codes of the plane of each angular point and the height position code are the same, indicating that the external rectangles are in the same grid, wherein the grid position code is the position code of any angular point; if the plane + height grid position codes of individual corner points are different, indicating that the corner points are not in the same grid, the grid at the upper level needs to be considered, if the corner points are all in the upper level (such as 18 levels), the grid position codes are 18-level grid codes, and the grid position codes are sequentially traversed until the plane + height grid position codes of all the corner points are the same.

A second aspect.

Referring to fig. 10, an embodiment of the present invention provides a multidimensional space adaptive partitioning and encoding system for a two-dimensional geographic entity, including:

the spatial position coding rule making module 10 is used for making a spatial position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity code length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional code combination rule.

A space type determining module 20, configured to determine a space type of a two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space types include: a plane type, a height type, and a plane + height type.

The space subdivision module 30 is used for determining a space subdivision mode corresponding to the space type according to the space type; wherein, the subdivision mode comprises: plane subdivision, height subdivision and plane + height subdivision.

And the spatial position coding module 40 is configured to code the two-dimensional geographic entity according to the spatial type and the spatial position coding rule.

The system provided by the invention formulates a space position coding rule for each type of two-dimensional geographic entity, and can automatically calculate the space position coding of each type of two-dimensional geographic entity by utilizing a derived formula; and the multi-dimensional subdivision grid where the two-dimensional geographic entity is located can be quickly positioned through space position coding.

In a third aspect.

The present invention provides an electronic device, including:

a processor, a memory, and a bus;

the bus is used for connecting the processor and the memory;

the memory is used for storing operation instructions;

the processor is configured to invoke the operation instruction, and the executable instruction enables the processor to perform an operation corresponding to the multidimensional space adaptive partitioning and encoding method for the two-dimensional geographic entity shown in the first aspect of the present application.

In an alternative embodiment, an electronic device is provided, as shown in fig. 11, the electronic device 5000 shown in fig. 11 includes: a processor 5001 and a memory 5003. The processor 5001 and the memory 5003 are coupled, such as via a bus 5002. Optionally, the electronic device 5000 may also include a transceiver 5004. It should be noted that the transceiver 5004 is not limited to one in practical application, and the structure of the electronic device 5000 is not limited to the embodiment of the present application.

The processor 5001 may be a CPU, general purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor 5001 may also be a combination of processors implementing computing functionality, e.g., a combination comprising one or more microprocessors, a combination of DSPs and microprocessors, or the like.

Bus 5002 can include a path that conveys information between the aforementioned components. The bus 5002 may be a PCI bus or EISA bus, etc. The bus 5002 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 11, but this is not intended to represent only one bus or type of bus.

The memory 5003 may be, but is not limited to, a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, an EEPROM, a CD-ROM or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The memory 5003 is used for storing application program codes for executing the present solution, and the execution is controlled by the processor 5001. The processor 5001 is configured to execute application program code stored in the memory 5003 to implement the teachings of any of the foregoing method embodiments.

Among them, electronic devices include but are not limited to: mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like.

A fourth aspect.

The present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements a method for multidimensional space adaptive partitioning and encoding of a two-dimensional geographic entity as shown in the first aspect of the present application.

Yet another embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, which, when run on a computer, enables the computer to perform the corresponding content in the aforementioned method embodiments.

Claims

1. A multi-dimensional space self-adaptive subdivision and coding method of a two-dimensional geographic entity is characterized by comprising the following steps:

formulating a space position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity coding length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional coding combination rule; the method specifically comprises the following steps:

adopting fixed length codes or indefinite length codes as length rules to code the two-dimensional geographic entities;

obtaining a maximum level and a minimum level of grid subdivision according to the maximum granularity and the minimum granularity of the two-dimensional geographic entity, and coding the two-dimensional geographic entity by taking the maximum level and the minimum level as grid level rules;

obtaining different coding combination rules according to different types of geographic entities, wherein the types comprise only plane coordinates, only elevation coordinates and plane and elevation coordinates at the same time;

determining a space type of a two-dimensional geographic entity according to the two-dimensional geographic entity, and determining a space range of the two-dimensional geographic entity according to the space type; wherein the space type includes: a plane type, a height type, and a plane + height type; the spatial range comprises a plane range, a height range and a plane + height range;

wherein the step of determining the planar extent comprises:

obtaining an extreme value of a plane coordinate according to the point set of the two-dimensional geographic entity, and determining the distribution range of the two-dimensional geographic entity in the plane coordinate direction;

generating a plane minimum circumscribed rectangle according to the distribution range, and calculating to obtain the longest edge of the plane minimum circumscribed rectangle;

the step of determining the height range comprises:

obtaining an extreme value of a height coordinate according to the point set of the two-dimensional geographic entity, and determining an elevation range of the two-dimensional geographic entity;

converting the extreme value of the height coordinate into an extreme value of geodetic height according to a plane coordinate conversion program;

according to the extreme value of the geodetic height, calculating to obtain the distance from the corner point of the two-dimensional geographic entity to the center of the sphere;

calculating the distance from the angular point of the two-dimensional geographic entity to the center of the sphere by adopting the following formula:

in the formula, X, Y, Z are respectively the spatial rectangular coordinates of the entity range, wherein:

X＝(N+D _min )cos Lat cos Lng

Y＝(N+D _min )cos Lat sin Lng

Z＝(N(1-e ² )+D _min )sin Lat

e ² ＝(a ² -b ² )/a ²

in the formula, e is the first eccentricity of the earth, N is the curvature radius of the earth prime unitary circle, a and b are respectively the long radius and the short radius of a CGCS2000 ellipsoid, lat and Lng are respectively the longitude and latitude coordinates of a two-dimensional geographic entity angular point, and D _min Is the minimum value of the earth height;

coding the two-dimensional geographic entity according to the space type and the space position coding rule, including:

if the space type is a plane + height type, encoding the two-dimensional geographic entity by adopting a plane + height code;

wherein the encoding the two-dimensional geographic entity using planar encoding comprises:

the encoding the two-dimensional geographic entity by adopting the altitude encoding comprises the following steps:

obtaining the height position codes of the highest point and the lowest point of the two-dimensional geographic entity in a height grid of m level respectively through iterative calculation, wherein m is more than or equal to 1 and less than or equal to 32;

if the spatial position codes of the highest point and the lowest point of the two-dimensional geographic entity in the height grids of the specified level are different, calculating whether the upper grid codes are the same, if so, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and traversing sequentially until the spatial position codes of the highest point and the lowest point are the same;

the encoding of the two-dimensional geographic entity using plane + altitude encoding includes:

obtaining the spatial position codes of the circumscribed rectangles and the elevation extreme points of the two-dimensional geographic entity on the s-level plane + height grid through iterative computation, wherein s is more than or equal to 1 and less than or equal to 32;

comparing the plane + height spatial position codes of all corner points of the two-dimensional geographic entity;

if the spatial position codes of all the angular points of the two-dimensional geographic entity in the grids of the designated level are different, whether the upper-level grid codes are the same or not is calculated, if so, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and the two-dimensional geographic entity is traversed sequentially until the spatial position codes of all the angular points are found to be the same.

2. The method of claim 1, wherein the determining the spatial partitioning method corresponding to the space type according to the space type comprises:

3. The method of claim 2, wherein the subdividing the two-dimensional geographic entity using planar subdivision comprises:

4. The method as claimed in claim 2, wherein the step of partitioning the two-dimensional geographic entity with a high partitioning comprises:

5. The method of claim 2, wherein the partitioning the two-dimensional geographic entity by plane + height partitioning comprises:

and sequentially recursing to form m-level height grids, wherein m is more than or equal to 1 and less than or equal to 32.

6. A multi-dimensional space self-adaptive subdivision and coding system of a two-dimensional geographic entity is characterized by comprising the following components:

the spatial position coding rule making module is used for making a spatial position coding rule of the two-dimensional geographic entity; wherein the spatial position encoding rule comprises: an entity coding length rule, a two-dimensional entity grid level rule and a two-dimensional entity multi-dimensional coding combination rule; the method specifically comprises the following steps:

wherein the step of determining the planar extent comprises:

the step of determining the height range comprises:

X＝(N+D _min )cos Lat cos Lng

Y＝(N+D _min )cos Lat sin Lng

Z＝(N(1-e ² )+D _min )sin Lat

e ² ＝(a ² -b ² )/a ²

the space type determining module is used for determining the space type of the two-dimensional geographic entity according to the two-dimensional geographic entity; wherein the space type includes: a plane type, a height type, and a plane + height type;

a spatial position coding module, configured to code the two-dimensional geographic entity according to the spatial type and the spatial position coding rule, including:

the encoding of the two-dimensional geographic entity with altitude coding comprises:

if the spatial position codes of the height grids of the highest point and the lowest point of the two-dimensional geographic entity at the designated level are different, calculating whether the upper-level grid codes are the same or not, if so, the spatial position codes of the two-dimensional geographic entity are the grid codes of the level, and sequentially traversing until the spatial position codes of the highest point and the lowest point are found to be the same;