CN112819942A

CN112819942A - Data processing method and device

Info

Publication number: CN112819942A
Application number: CN201911119349.6A
Authority: CN
Inventors: 刘勇
Original assignee: Zhongke Star Map Co ltd
Current assignee: Zhongke Star Map Co ltd
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2021-05-18

Abstract

The invention provides a data processing method and a device thereof, in particular to a data processing method and a device thereof for three-dimensional geographic information visual field analysis. The data processing method of the present invention includes a visual point setting step of setting a visual point in a prescribed area; a data acquisition step of acquiring data of a region around a visual point; a preprocessing step of preprocessing the acquired data, wherein the elevation values of all points in the area are calculated based on a Delaunay triangulation algorithm; and a visual field determination step of determining a visual field of the surrounding area centered on the visual point. According to the invention, the response time of data analysis and processing is prolonged, and the accuracy and performance of analysis are improved.

Description

Data processing method and device

Technical Field

The invention relates to a data processing method and a device thereof, in particular to a data processing method and a device thereof for three-dimensional geographic information visual field analysis.

Background

With the development of computer realistic graphics technology, it is becoming more and more common to represent terrain using three-dimensional technology. The analysis and display of the geographic related information in the 3DGIS are main functions, the three-dimensional space analysis and operation are carried out on the space object, and the three-dimensional GIS is an important characteristic, and the visual domain analysis is a part of the three-dimensional GIS. The application of the visual field analysis is very wide, such as the selection of the optimal position of a television tower, the arrangement of a radar station and the like. The three-dimensional geographic information technology (3D GIS) is utilized to assist the site selection of the mobile communication base station, and the position of the site and the communication coverage range thereof, the overlapping area of the coverage ranges among multiple sites and the like can be visually and intuitively displayed.

However, in the mainstream simultaneous analysis algorithm, the 4 algorithms, i.e., the JANUS algorithm, the DYNTACS algorithm, the ModeSAF algorithm, and the Bresenham algorithm, are mainly used, and for larger three-dimensional geographic information data, the use of the 4 algorithms generally consumes more time and fails to consider the influence of the curvature of the earth.

Disclosure of Invention

In view of the above-described problems of the prior art, the present invention provides a data processing method, comprising: a visual point setting step of setting a visual point in a predetermined area; a data acquisition step of acquiring data of a region around a visual point; a preprocessing step of preprocessing the acquired data, wherein the elevation values of all points in the area are calculated based on a Delaunay triangulation algorithm; and a visual field determination step of determining a visual field of the surrounding area centered on the visual point.

According to the invention, the visual field extraction optimization method based on the triangular mesh comprises the processes of triangular mesh generation and visual field analysis; and (3) obtaining a better triangular mesh result by using a Delaunay triangulation algorithm, and analyzing the position of the visual point on the basis to finally obtain an analysis result. Furthermore, according to the present invention, the method of the through-the-horizon analysis of the DEM (Digital Elevation Model) data based on the triangular mesh analyzes and extracts the visual situation around the visual point by the analysis and triangulation of the raster data. Meanwhile, the acquisition mode of the grid elevation value is optimized for the larger geographic information data, so that the response time of analysis is prolonged, and the accuracy and the performance of the analysis are improved.

Preferably, in the data acquiring step, a rectangle of the area is constructed according to the longitude and latitude of the visual point and the distance of visibility, and corresponding data is loaded according to the area request.

Therefore, the data reading amount can be further optimized, and the responsiveness of the visual field analysis data processing is improved.

In addition, the data processing method of the present invention is preferable, in the preprocessing step, whether an invalid value exists in the obtained elevation value is determined, and if yes, a bilinear difference is performed according to the elevation value of the area to calculate the elevation value of the point. Thereby greatly improving the accuracy of the visual field analysis. The invalid value is an altitude value of the acquired data, which is negative, or a value of "NAN" which is extremely large, and the acquired data can be unified into a usable altitude value according to the preprocessing step.

Preferably, the data processing method of the present invention further includes, after the determining step, a visibility rate calculation step of calculating a visibility rate by counting the visibility points in the visual field determined based on the visibility points.

By calculating the visibility, the user can intuitively obtain the quality of the visual field based on the visual point.

In the data processing method according to the present invention, it is preferable that the visual field determining step divides the visual points by a predetermined angle for one circle, and compares elevation values of points on the respective visual lines in the determination area with the visual points using each division line as one visual line, and determines that the visual points are visible when the elevation values are smaller than the elevation values of the visual points, or determines that the visual points are invisible when the elevation values are not smaller.

Therefore, the accuracy of the visual field analysis can be adjusted by adjusting the division angle, and the processing speed and the processing accuracy can be well balanced.

The present invention also provides a data processing apparatus, comprising: an input unit that accepts setting of a visual point in a predetermined area by a user; a reading unit that acquires data of an area around a visual point from the visual point input by the input unit; the preprocessing part is used for preprocessing the acquired data and calculating the elevation value of each point in the area based on the Delaunay triangulation algorithm; and a determination unit that determines a visible area of a peripheral area around the visible point.

According to the data processing device, the response time for analyzing the visual domain of the three-dimensional geographic information can be prolonged, and the accuracy and the performance of analysis are improved.

Further, in the data processing device according to the present invention, it is preferable that the reading unit constructs a rectangle of the area based on the latitude and longitude of the visual point and the viewing distance, and loads the corresponding data in accordance with the area request. Therefore, the data reading amount can be further optimized, and the responsiveness of the visual field analysis data processing is improved.

In the data processing apparatus according to the present invention, it is preferable that the preprocessing unit determines whether or not an invalid value exists in the acquired elevation values, and if so, calculates an elevation value at the point by performing a bilinear difference on the elevation values of the area. Thereby greatly improving the accuracy of the visual field analysis.

Further, it is preferable that the data processing device further includes a calculation unit for performing statistics based on the visibility points in the visible region determined by the determination unit to calculate the visibility ratio. Thereby facilitating the user to intuitively obtain the quality of the visual field based on the visual point.

In the data processing device according to the present invention, it is preferable that the determination unit divides the visual points by a predetermined angle in a circle, determines each of the division lines as a line of sight, compares elevation values of points on each line of sight in the determination area with the visual points, and determines that the visual points are visible when the elevation values are smaller than the elevation values of the visual points, and otherwise determines that the visual points are invisible. Therefore, the accuracy of the visual field analysis can be adjusted by adjusting the division angle, and the processing speed and the processing accuracy can be well balanced.

Drawings

Fig. 1 is a block diagram of a data processing apparatus according to an embodiment of the present invention.

Fig. 2 is a flowchart of processing performed by the data processing apparatus according to the present embodiment.

Fig. 3 is a schematic diagram of the Delaunay triangulation algorithm.

Fig. 4 is a schematic diagram showing the respective communication lines determined by the determination unit.

Detailed Description

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The data processing device of the embodiment is used for three-dimensional geographic information visual field analysis. As shown in fig. 1, the data processing apparatus 100 of the present embodiment includes: an input unit 110, a reading unit 120, a preprocessing unit 130, a judgment unit 140, and a calculation unit 150. The various parts may be connected and communicate with each other via a bus 160. Next, the data processing device and the processing flow thereof according to the present embodiment will be described in detail with reference to the flowchart of fig. 2.

The input unit 110 accepts setting of a visual point in a predetermined area by a user. The reading unit 120 acquires data of an area around the visual point from the visual point input by the input unit 110. In the present embodiment, in order to improve the efficiency of data processing, the user can simultaneously input the visibility of the atmosphere, the visibility range, and the visibility range through the input unit 110, and the reading unit 120 calculates the area to be currently analyzed based on the information input through the input unit 110, thereby reducing the load in the subsequent calculation of the visibility. The reading unit 120 may acquire data of the area around the visible point by various methods such as service or local reading, but this is not limited in the present embodiment.

The preprocessor 130 preprocesses the acquired data, the decision unit 140 decides a visible area of a surrounding area around a visible point, and the calculator 150 calculates a visibility rate by counting the visibility points in the visible area decided based on the visible points.

Next, the data processing device and the processing flow thereof according to the present embodiment will be described in detail with reference to the flowchart of fig. 2.

First, in step S1, the input unit 110 receives an input from the user, and a visual point is set in a predetermined area, thereby completing visual point selection. In the present embodiment, in step S2, the visibility of the atmosphere, the visibility range, and the visibility range input by the user are also received by the input unit 110, so that the visibility can be determined more accurately, the efficiency of data processing can be improved effectively, and the load on the calculation of the visibility described below can be reduced.

Next, in step S3, the reading unit 120 calculates an area to be analyzed currently from the information input by the input unit 110, and acquires data of the area around the visible point by various means such as service or local reading.

Then, the preprocessing unit 130 preprocesses the data input from the reading unit 120 in step S4, determines whether or not the acquired elevation values have an invalid value such as a negative elevation value or an extremely large value such as "NAN", and if it is determined in step S5 that the acquired elevation values have an invalid value, calculates an elevation value of the area from the elevation values of the area by bilinear difference calculation in step S9, and performs fault-tolerant processing on the invalid value.

And in step S6, the elevation values of the points in the area are calculated based on the Delaunay triangulation algorithm after the data subjected to the above-described processing.

Fig. 3 is a schematic diagram of the Delaunay triangulation algorithm. The Delaunay triangulation algorithm is basically configured in such a way that, for a point set E, an edge of the point set E is assumed to be E (two end points are a and b), and if the following condition is satisfied, the edge is called a Delaunay edge, that is, a circle passes through two points a and b, and no other point in the point set E is contained in the circle (note that in the circle, most three points on the circle are in a common circle), which is also called a hollow circle characteristic. Delaunay triangulation: if a triangulation T of the set of points E contains only Delaunay edges, the triangulation is referred to as a Delaunay triangulation.

Compared with the conventional JANUS algorithm, DYNTACS algorithm, ModeSAF algorithm and Bresenham algorithm, the Delaunay triangulation has the following advantages: 1. the closest is: the triangle is formed with the nearest three points and none of the line segments (triangle side e) intersect. 2. Uniqueness: consistent results will eventually be obtained regardless of where the region is built. 3. Optimality: if the diagonals of the convex quadrangle formed by any two adjacent triangles can be interchanged, the smallest angle in the six interior angles of the two triangles cannot be enlarged. 4. Most regular: the arrangement of the Delaunay triangulation results in the largest value if the smallest angles of each triangle in the triangulation are arranged in ascending order. 5. Regionality: when a certain vertex is added, deleted or moved, only the adjacent triangle is influenced. 6. Housing with convex polygon: the outermost boundaries of the triangulation network form a convex polygonal outer shell.

Then, in step S7, the determination unit 140 divides the visual point by 360 degrees in units of 1 ° for each circle, considers each degree as one line of sight, calculates the plane distance between the visual point and each degree, determines the size of the elevation point along the line, determines that the elevation is visible if the height is smaller than the visual point, and determines the visual field of the surrounding area centered on the visual point if the elevation is not visible.

Fig. 4 is a schematic diagram showing the respective communication lines determined by the determination unit. As shown in fig. 4, point P is designated as a visible point on the three-dimensional geographic information map, and the three-dimensional geographic information map is divided by 1 ° from point P to form 360 lines of sight. For the convenience of demonstration and explanation, only 6 through-view lines are marked with bold marks, the black solid line part on the through-view line represents the visible vision, and the black and white alternate dotted line part represents the invisible vision. Accordingly, the determination unit determines the through-line image having the point P as the visible point.

Next, in step S8, the calculation unit 150 calculates the visibility rate by performing statistics on the visibility points in the visual field determined by the determination unit 140. Therefore, the visibility rate when the visible point is set to be the point P can be visually output to the user, and the user can use the device conveniently.

In the present embodiment, 360 lines of sight are generated by division in units of 1 ° with the visible point P as the center, but the lines of sight may be generated by flexibly adjusting a predetermined division angle as necessary, so that the processing speed and the processing accuracy are well balanced.

Moreover, the invention is based on the Delaunay triangulation algorithm, so that when the visual point is changed, the constructed triangulation network in the area around the changed visual point does not need to be changed, thereby greatly reducing the calculation amount. The responsiveness of data processing can be greatly improved for the case where the visual field continuously changes when the visual point is continuously dragged. And, in the present invention, the influence of the earth curvature on the calculation of the visual field can be completely overcome by using the Delaunay triangulation algorithm.

While the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made by those skilled in the art without departing from the scope of the present invention as set forth in the claims.

Claims

1. A data processing method, comprising:

a visual point setting step of setting a visual point in a predetermined area;

a data acquisition step of acquiring data of a region around a visual point;

a preprocessing step of preprocessing the acquired data, wherein the elevation values of all points in the area are calculated based on a Delaunay triangulation algorithm; and

and a visual field determining step of determining a visual field of the surrounding area centered on the visual point.

2. The data processing method of claim 1, wherein:

in the data acquisition step, a rectangle of the area is constructed according to the longitude and latitude of the visual point and the distance of visibility, and corresponding data is loaded according to the area request.

3. The data processing method of claim 1, wherein:

and in the preprocessing step, judging whether the obtained elevation value has an invalid value, and if so, calculating the elevation value of the point according to the elevation value of the area by carrying out bilinear difference.

4. A data processing method according to claim 3, characterized by:

and after the judging step, the method further comprises a visibility rate calculation step of counting the visibility points in the visual field judged based on the visibility points and calculating the visibility rate.

5. The data processing method of claim 4, wherein:

in the step of judging the visual field, the visual points are divided into a circle by a preset angle, each division line is used as a communication line, the elevation value of each communication line point in the judgment area is compared with the visual point, the visual point is judged to be visible when the elevation value is smaller than the elevation value of the visual point, and the visual point is judged to be invisible when the elevation value is not smaller than the elevation value of the visual point.

6. A data processing apparatus, comprising:

an input unit that accepts setting of a visual point in a predetermined area by a user;

a reading unit that acquires data of an area around a visual point from the visual point input by the input unit;

the preprocessing part is used for preprocessing the acquired data and calculating the elevation value of each point in the area based on the Delaunay triangulation algorithm;

and a determination unit that determines a visible area of a peripheral area around the visible point.

7. The data processing apparatus of claim 6, wherein:

the reading part constructs a rectangle of the area according to the longitude and latitude of the visual point and the distance of visibility, and loads corresponding data according to the area request.

8. The data processing apparatus of claim 6, wherein:

and the preprocessing part judges whether the obtained elevation value has an invalid value or not, and if so, calculates the elevation value of the point according to the elevation value of the area by bilinear difference.

9. The data processing apparatus of claim 8, wherein:

the device further comprises a calculation unit which calculates the visibility rate by performing statistics on the visibility points in the visual field determined by the determination unit.

10. The data processing apparatus of claim 9, wherein:

the judging part divides the visual points by a predetermined angle in a circle, takes each division line as a through visual line, compares the elevation value of each point on each through visual line in the judging area with the visual point, judges that the visual point is visible if the elevation value is less than the elevation value of the visual point, and judges that the visual point is invisible if the elevation value is not.