JP2001108435A - Method for generating three-dimensional coordinate information concerning topography or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for generating three-dimensional information where an object to be measured, e.g. topography, is converted into data for drawing. SOLUTION: The inventive method comprises a step for generating actual measurement point data by actually measuring arbitrary points of an object to be measured, e.g. topography, randomly and collecting the three-dimensional coordinate data at each actual measurement point, a step for generating altitude point data by connecting the actual measurement points to form coupling lines constituting a polygonal plane group and then determining an altitude point corresponding to a specified altitude value on the coupling line, a step for generating contour line data representative of the contour line by connecting the altitude points corresponding to specified altitude values, a step for generating plan view information which can indicate a visible contour line from the contour line data, and a step for generating mesh drawing information by superposing mesh data indicative of lattice lines on the plan view information and calculating the three-dimensional coordinate of mesh points at the intersections of the lattice lines from the actual measurement point data included in the plan view information and/or actual measurement approximation point data formed by the intersections of the contour lines and the lattice lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating three-dimensional coordinate information in which a measurement object such as terrain is converted into data for a drawing, and relates to plan view information with contour lines and cubic information of mesh points. An object is to provide mesh diagram information having original coordinate data.

[0002]

2. Description of the Related Art Conventionally, for example, for a development plan such as a road development or a residential land development, a drawing such as a current state map representing the topography is required. It is generally provided as a diagram. Therefore, when creating such a plan view, the survey points located on the mesh are determined by setting a mesh on the terrain to be measured, and the data is converted into a mesh diagram while obtaining the three-dimensional coordinates of each measurement point by on-site survey. A method of writing and then adding contour lines has been implemented.

[0003]

However, the conventional drawing method as described above requires a great deal of time and cost because a very large number of measuring points located on a mesh must be measured at the site.

[0004] In addition, there are also scenes in which a terrain or the like that cannot be actually measured is encountered at the site. In this case, it is necessary to measure the vicinity of the measurement point and estimate the measurement value of the measurement point. Reliability decreases.

In particular, since contour lines connecting measurement points depend on the freehand drawing of the plotter, it is inevitable that an error will occur. Therefore, after the contour lines are written, the contour lines are again drawn on the contour lines. There is an inconvenience that on-site surveys must be repeatedly performed to create a highly accurate drawing, for example, by actually measuring a new measuring point located.

Incidentally, in order to obtain permission from the administrative agency in charge of the development plan and the like, it is necessary to present a land transportation plan in addition to the current ground plan represented by contour lines. As a method for calculating the soil volume, a sectional method and a mesh method are known. Therefore, if the mesh diagram is completed in the conventional method, it can be used as data for calculating the soil volume by the mesh method.
The measurement points that cannot be measured as described above are left blank without data, and are insufficient as data for calculating the soil volume by the mesh method, and even if the mesh diagram can be completed, the mesh method In order to calculate the soil volume by computer, it is necessary to input the data to the computer again.

Further, as will be described later, according to the present invention, in addition to calculating soil volume,
It can be used for various purposes such as creating a bird's-eye view,
Since the mesh diagram handwritten by the conventional method is merely a basic material for drawing contour lines, it is destined to be discarded after completing the current plan view with contour lines and completing its role.

[0008]

Therefore, in order to solve the above-mentioned problems, the present invention is configured as a first means. An arbitrary measurement point on an object to be measured, such as terrain, is measured at random, and each actual measurement point is measured. A step of creating actual measurement point data by collecting three-dimensional coordinate data of the three-dimensional coordinate data, and creating a connection line constituting a polygon plane group by connecting the actual measurement points,
A step of generating elevation point data by obtaining an elevation point corresponding to a predetermined elevation value on the connection line; and a step of generating contour line data representing a contour line by connecting the elevation points corresponding to the predetermined elevation value. And a step of generating, from the contour line data, plan view information that enables display of contour lines visually recognizable by the naked eye.

When creating elevation point data, it is preferable to form a group of triangle planes having vertices at the actual measurement points by connecting lines connecting the actual measurement points. At this time, the triangles are as close as possible to equilateral triangles. Preferably, it is shaped.

When creating contour data, it is preferable to form contour lines using spline curves passing through elevation points corresponding to predetermined elevation values.

[0011] Further, the present invention is configured as a second means in that the plan view information creating step, the elevation point data creating step, and the contour line data creating step as described above are performed. After the creation process, mesh data representing a grid line is superimposed on the plan view information, and three-dimensional coordinates of mesh points appearing at intersections of the grid lines are obtained by calculation from actual measurement point data included in the plan view information. Thus, there is a step of creating mesh diagram information.

Further, the present invention is configured as a third means in that the plan view information creating step, the elevation point data creating step, and the contour line data creating step as described above are used to generate the plan view information. After the creation process, superimposing mesh data representing grid lines on the plan view information, and calculating three-dimensional coordinates of mesh points appearing at intersections of grid lines by calculation from elevation points included in the plan view information. In which mesh drawing information is created by the following method.

Further, the present invention is configured as a fourth means. The step of creating the actual measurement point data, the step of creating the elevation point data, and the step of creating the contour line data as described above, After the creation process, mesh data representing grid lines are superimposed on the plan view information, and three-dimensional coordinates of actually measured approximate points formed by intersections of the contour lines of the plan view information and the grid lines of the mesh data are obtained. Thus, there is a step of generating actual measurement approximate point data and a step of generating mesh diagram information by calculating three-dimensional coordinates of mesh points appearing at intersections of grid lines by calculation from the actual measurement approximate point data. .

In the second to fourth means, the least squares method can be used when calculating the three-dimensional coordinates of the mesh points.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 4 show steps in a method for creating three-dimensional coordinate information according to an embodiment of the present invention. FIG. 6 shows a hardware configuration for implementing the method. FIG. 7 shows a work flow corresponding to each step of the creation method, and FIG. 8 shows an equation of the least square method for calculating the three-dimensional coordinates of the mesh points by calculation.

(Hardware Configuration) The hardware for carrying out the method for creating three-dimensional coordinate information according to the present invention includes:
Although not limited to the embodiment shown in FIG.
In order to perform surveying by actual measurement at a site, a surveying instrument 1 and a portable small site computer 2 are used.
The surveying instrument 1 is, for example, a publicly known GPS (Global Positio
A global positioning system 1a referred to as a “ning system” and an optical distance measuring goniometer 1b referred to as a “total station” can be optionally used. It is preferable that the portable on-site computer 2 use, for example, an electronic flat plate (trade name: GUIDER) manufactured and sold by the present applicant. The surveying instrument 1 and the on-site computer 2 can transmit and receive data to and from each other via the respective wireless devices 3a, 3b, and 4, and convert the three-dimensional coordinate data of the actual measuring points measured by the surveying instrument 1 into the actual measuring point data. And stored in the computer 2 for the site.

The on-site computer 2 has a function of creating a connecting line connecting actual measurement points as described later, a function of creating elevation point data for obtaining an elevation point on the connecting line, and representing contour lines by connecting elevation points. It has a function of creating contour data, a function of setting a mesh composed of grid lines, and the like, and has an operating means such as a pen means, a display, and an external storage medium such as an FD or PD. If the display is configured so that a mesh can be set, points on the same mesh can be observed as if navigating. Therefore, even if the terrain changes during the survey period, observation can be performed at the same point. .

The data in the on-site computer 2 is:
The data is transferred directly to the host computer 5 via the LAN or indirectly via an external storage medium such as an FD or PD. The host computer 5 constitutes an RDB-type fusion CAD system capable of performing survey calculation and CAD, and has a function of creating a connecting line connecting actual measurement points as described later, and obtaining an elevation point on the connecting line to obtain an elevation. A function to create point data, a function to create contour data that represents contour lines by connecting elevation points, a function to set meshes that represent grid lines, and the creation of mesh diagram information by finding the three-dimensional coordinates of mesh points The main memory 7 stores various data input via the interface 6, and is controlled by the CPU 8 and includes a display 9, a keyboard 10, a printer 11, and the like as attached devices.

As described above, the actual measurement point data of the site measured by the surveying instrument 1 is input to the on-site computer 2 having good workability, where a connecting line connecting the actual measurement points as described later is prepared. A step of creating elevation point data for finding an elevation point on the connection line and a step of creating contour line data representing the contour line are executed. However, since the memory capacity is limited, these created data are occasionally transferred to the host computer. 5
, Where it is processed and stored. However,
As shown by the dashed line in FIG. 6, the on-site computer 2 is omitted, and the measured data of the surveying instrument 1 is directly input to the host computer 5 via a telephone line or wireless communication.
All subsequent steps of the present invention may be configured to be executed by the host computer 5.

The host computer 5 has, as an external device, a digitizer 1 for reading existing drawings.
2 and / or a scanner 13 are connected, and more preferably, a plotter 14 for printing a drawing at high resolution on a large sheet of paper is connected.

(Preparation Step of Actual Measurement Point Data) First, an actual measurement by on-site surveying is performed by using the surveying instrument 1 for an object to be measured, such as a topography, on which a construction plan is to be implemented. At the time of this survey, there is no need to mesh the terrain to be measured as in the past. To the computer 2 for use. Therefore, the on-site computer 2 has a random measurement point P represented by three-dimensional coordinates X (east-west), Y (south-north), and Z (elevation) as shown in FIG.
1, P2, P3,... Pn are sequentially stored, and a large number of them are accumulated, thereby creating actual measurement point data (FIG. 7).
(A) STEP A-1). At this time, the actual measurement points P1, P
2... The denser the Pn, the higher the accuracy of the plan view information and mesh diagram information created later, but the density of the actually measured points is, A complicated topographical region having a remarkable change may be processed flexibly, for example, by increasing the density.

(Connecting line creation step) When the actual measurement point data is accumulated in a predetermined measurement area, the actual measurement points P1, P2,. A connection line L forming a group is created (STEP A-2 in FIG. 7A). The connecting line L forms a mathematical line segment for calculating a predetermined elevation point on the connecting line from the coordinates of the actually measured point, as described later. Therefore, the polygon formed by the connecting line L may be a quadrangle or a pentagon,
In order to create as many connecting lines L as possible, it is preferable to make the shape triangular, and it is more preferable to make the shape as close as possible to an equilateral triangle. In the case of an equilateral triangle, the distances between the actually measured points P1, P2,... Pn located at the vertices are equal to each other, which facilitates calculation when obtaining an elevation point for a contour line described later. Therefore, the CAD stored in the computer (on-site computer 2 or host computer 5)
It is preferable that the software includes a program for automatically determining a triangle formed by connecting the input actual measurement points P1, P2,... Pn so as to be a combination closest to an equilateral triangle. However, as shown in the figure, all the actual measurement points P1, P2,.
On the other hand, it is preferable to connect all adjacent measurement points to each other by a connection line L. For example, when there are extra measurement points that are not always necessary for forming an equilateral triangle as described above, Connecting line L to the actual measurement point
Need not be tied.

(Step of Creating Elevation Point Data) When the above-mentioned connecting line L is specified, as shown in FIG.
An elevation point h1 corresponding to a predetermined elevation value on each connecting line L;
The height point data is created by calculating h2, h3,... hn (STEP A-3 in FIG. 7A). Since the elevation points are data for creating contour lines, as described later, the elevation differences between adjacent elevation points on the connecting line are equal to each other (that is, h2-h1 = h3-h2 = h4-h3).
...). Therefore, the elevation points (elevation coordinates Z = hi) corresponding to each elevation value are obtained by calculation from the coordinates (X, Y, Z) of the measurement points P located at both ends of the connection line L. For example, in the case of the example shown in FIG.
The inclined line segment (connecting line L) connecting P3 and P3 is the coordinates of both actual measurement points (P1 = X1, Y1, Z1; P3 = X3, Y3, Z3)
, The length of the line segment is obtained by a calculation using a trigonometric function or the like, and then a predetermined elevation coordinate (Z = h4, Z = h5, Z
= H6) (ie, altitude points h4, h5, h
6) is obtained, and thereby the elevation point data is created and stored. When the altitude points h1, h2,... Hn are used as data for calculating the coordinates of the mesh points as described later, the altitude coordinates (Z = hi) and the coordinates (X, Y, Z) of the measured points P at both ends of the connecting line L, the plane coordinates (X, Y) of the elevation points h1, h2,. ) And add it to the elevation data.

(Steps for Creating Contour Line Data) As described above, the elevation points h1, h2, h3,.
Is specified, contour data representing the contour lines C1, C2, C3... Cn is created by drawing a spline curve passing through an elevation point corresponding to a predetermined elevation value (see FIG. 3). Step A-4 in FIG. 7A). At this time, although not shown, a tangent plane to each vertex of the triangular plane group connected by the connection line L is calculated, and each triangular plane is divided into four triangular planes so as to approximate a curved surface. Therefore, since the triangular plane groups approximated by curved surfaces share the end points in all regions, the contour lines are joined in order from the start point to the end point.

(Steps of Creating Plan View Information) The contour lines C1, C that can be visually recognized by the display 9, the printer 11 or the plotter 14 when output are output.
2, C3... Cn are created as plan view information that can be displayed and stored in the main memory (ST in FIG. 7A).
EP A-5). In addition, this drawing information is FD, PD, CD
May be stored in a recording medium such as. Therefore, when a current ground plan represented by contour lines is required to obtain the permission of the administrative agency in charge, such as in a construction plan, by outputting this ground plan information, the current ground plan with contour lines can be output at any time. Can be provided.

(First Embodiment of Creating Mesh Diagram Information:
Step of creating mesh diagram information based only on plan view information) As described above, the RDB-type fusion CAD of the host computer 5
The system has a function for setting a mesh representing a grid line and a function for obtaining three-dimensional coordinates of mesh points and creating mesh diagram information. Therefore, the plan view information input to the host computer 5 can be superimposed with the mesh of the mesh data on the plan view information as shown in FIG. 4 (STEP C-1 in FIG. 7C).
a). This plan view information includes “STEP A-
1 and the actual measurement point data created in "STEP A".
-3 ", the three-dimensional coordinates (Xm) of the mesh point Pm (the intersection of the vertical and horizontal grid lines M and M) are based on the actual measurement point data and / or the elevation point data. , Ym, Zm) are calculated (STEP C-2a in FIG. 7C). When the writing of the three-dimensional coordinates is completed for all the mesh points in the predetermined area, the creation of the mesh diagram information is completed and stored (STEP C-3 in FIG. 7C).

At this time, among the three-dimensional coordinates of each mesh point Pm, elevation coordinates (ZZ) other than two-dimensional coordinates (Xm, Ym) are used.
m) can be used as a calculation method for obtaining the least square method (a calculation method that minimizes the sum of squares of the difference (residual error) between the calculated point (most probable value) and the known point (measured value)), A mesh point that is a calculated point (most probable value), using coordinates of the actually measured points P1, P2... Pn and / or elevation points h1, h2. The elevation coordinates (Zm) of Pm can be obtained.

That is, for example, in the case of the diagram shown in FIG. 4, a predetermined mesh portion (shaded portion in FIG. 4) surrounding the calculated point (ie, the mesh point Pm) includes an actual measurement included in the plan view information. Point P1, P2... Pn and / or elevation point h1, h
2... Hn, actual measurement points P5 and P7 and elevation point h
1, h2, h3 exist, and these actual measurement points P5,
The three-dimensional coordinates of P7 and the elevation points h1, h2, h3 are already stored as data in the plan view information. Regarding this point, a group of points in the space represented by the coordinates Xi, Yi, Zi can be represented by a plane equation: z = ax + by + c (Equation 1). Therefore, the coordinates of the mesh point Pm to be obtained are Zm = aXm + bYm + c (Equation 2). Therefore, if the least squares method is used, the values (most probable values) of the a, b, and c can be obtained by (Equation 3), (Equation 4), and (Equation 5) shown in FIG. , B, c
And the two-dimensional coordinates (Xm, Y
By substituting the value of m) into (Equation 2), the desired value Zm
Can be calculated.

When the coordinates of the mesh point Pm are obtained by calculation such as the least square method by referring to the three-dimensional coordinate data included in the plan view information, the actually measured points P1, P2,. ... Of the two types of data, the three-dimensional coordinate data of Pn and the three-dimensional coordinate data of elevation points h1, h2,... Hn, only one of the data may be cited. The quotation may be switchable, but the configuration may be such that the three-dimensional coordinate data of both the actual measurement point P and the elevation point h can be quoted at the same time.

(Second Embodiment for Creating Mesh Diagram Information:
Step of creating mesh diagram information based on processing data of plan view information) In the method of creating mesh diagram information in the present invention, quoted actual measurement point data and / or elevation point data already included in the plan view information as described above. After superimposing the mesh of the mesh data on the plan view information input to the host computer 5 (FIG. 7C)
STEP C-1a), as shown in FIG. 5, an actual measurement approximate point q is formed by the intersection of the contour lines C1, C2... Cn of the plan view information and the grid line M of the mesh data, and this point q
By calculating the three-dimensional coordinates of the actual measurement approximate point data, the three-dimensional coordinates (Xm, Ym, Zm) of the mesh point Pm are calculated from the three-dimensional coordinates of the actual measurement approximate point q. Invention can be achieved (FIG. 7)
(C) STEP C-2b). When the writing of the three-dimensional coordinates to all the mesh points in the predetermined area is completed, the creation of the mesh diagram information is completed and saved (S in FIG. 7C).
TEP C-3).

The actually-measured approximate point data is obtained by calculating the elevation coordinates Z based on the contour lines C1, C2,.
(Ie, h1, h2... Hn) and the plane coordinates (X, Y) on the grid line M of the mesh, so that the three-dimensional data is created. The values of a, b, and c obtained by calculation using the least-squares method shown in FIG. 8 from the three-dimensional coordinates of the actually measured approximate point q and the mesh point Pm By substituting the values of the two-dimensional coordinates (Xm, Ym) into the plane equation: Zm = aXm + bYm + c, it is possible to calculate the three-dimensional coordinates of the mesh point Pm as the desired point.

(Other Technical Forms for Creating Mesh Diagram Information) As shown in FIG.
If you connect the digitizer 12 or scanner 13 to
In addition to the method for creating mesh diagram information according to the present invention described above, mesh diagram information can also be created from existing existing drawings created in the past.

When the digitizer 12 reads a paper drawing on which contour lines provided as a current state drawing are drawn, vector data is created while reading the coordinates of the contour lines. When the same paper drawing is read by the scanner 13, vector data is created while automatically converting the coordinates of the contour lines into vectors (STEP B-1 in FIG. 7B). Then, when these vector data are input to the host computer 5, contour data is created by performing contour line heightening processing (STEP B in FIG. 7B).
-2). Based on the contour data, read drawing information for displaying contour lines that can be visually recognized by output to the display 9, the printer 11, or the plotter 14 is created and stored in the main memory (STEP B- in FIG. 7B).
3). The drawing information may be stored in a recording medium such as an FD, a PD, and a CD. Therefore, when a current ground plan represented by contour lines is required to receive the permission of the administrative agency in charge, such as a construction plan, by outputting this read drawing information, the current ground plan with contour lines can be output at any time. Can be provided.

In order to create mesh diagram information from the read drawing information, a mesh of the mesh data is superimposed on the read drawing information (STEP in FIG. 7C).
C-1b) Similarly to the embodiment shown in FIG. 5, forming an actual measurement approximate point q by an intersection of a contour line of read drawing information and a grid line of mesh data, and obtaining three-dimensional coordinates of this point q , And the three-dimensional coordinates (Xm, Ym, Zm) of the mesh point Pm are calculated from the three-dimensional coordinates of the actually measured approximate point q (FIG. 7).
(C) STEP C-2b). When the writing of the three-dimensional coordinates to all the mesh points in the predetermined area is completed, the mesh diagram information is created and saved (STEP in FIG. 7C).
C-3). The calculation method is the same as in the embodiment described above with reference to FIG.

(Use of Mesh Diagram Information) The mesh diagram information can be used for calculating the soil volume using the mesh method as described above, and is already completed as a mesh diagram.
By using the CAD of the host computer 5,
A bird's-eye view or a cross-sectional view can be freely created based on the mesh diagram information.
It can be provided in a display form that can be visually recognized through the plotter 1 or the plotter 14.

[0037]

According to the present invention, the actual measurement points (P1, P2,...) Are collected by the on-site worker randomly measuring arbitrary measurement points and inputting them to a computer.
.. Pn) only by creating actual measurement point data consisting of three-dimensional coordinate data. Thereafter, data creation of a connecting line (L) forming a group of triangular planes connecting the actual measuring points and elevation points ( h) and data creation of contour lines (C) representing contour lines connecting the elevation points are automatically performed on a computer, thereby creating plan view information with contour lines. As a result, there is an effect that the labor of the on-site work can be greatly reduced and a highly accurate drawing can be provided.

The plan view information can be provided not only as a current state drawing that allows contour lines to be visually recognized by the naked eye, but also by superimposing mesh data on the plan view information to obtain actual measurement points created in the process of creating the plan view information. The mesh point (Pm) is obtained by using the data and / or the elevation point data as they are and / or by creating and using the data of the actual measurement approximate point (q) formed by the intersection between the contour line of the plan view information and the mesh. 3D coordinates are obtained by calculation, and mesh diagram information is created by this. Therefore, a mesh diagram can be created and provided extremely quickly and accurately, and a soil volume calculation by a mesh method and a bird's-eye view by a CAD system can be performed. And contribute to drawing of a cross-sectional view.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a step of creating actual measurement point data and a step of creating connection line data according to an embodiment of the present invention.

2A and 2B show a process of creating elevation point data according to an embodiment of the present invention, wherein FIG. 2A is a plan view and FIG. 2B is a side view.

FIG. 3 is a plan view illustrating a process of creating contour line data according to an embodiment of the present invention.

FIG. 4 is a plan view showing a step of creating mesh diagram information in the embodiment of the present invention and illustrating a first embodiment of a method of obtaining coordinate data of mesh points.

FIG. 5 is a plan view illustrating a step of creating mesh diagram information according to an embodiment of the present invention and illustrating a second embodiment of a method of obtaining coordinate data of mesh points.

FIG. 6 is a block diagram showing an example of a hardware configuration for implementing one embodiment of the present invention.

FIG. 7 is a flowchart illustrating an example of a work procedure when implementing the present invention.

FIG. 8 is a mathematical expression showing an example of the least squares method used in the embodiment of the present invention.

[Explanation of symbols]

 P actual measurement point L connecting line h elevation point C contour line Pm mesh point q actual measurement approximate point

Claims (7)

[Claims] 1. A step of randomly measuring an arbitrary measurement point on a measurement target such as terrain and collecting three-dimensional coordinate data of each actual measurement point to create actual measurement point data; and connecting the actual measurement points. Creating a connecting line that forms a group of polygonal planes, and generating elevation point data by obtaining an elevation point corresponding to a predetermined elevation value on the connection line; and an elevation point corresponding to the predetermined elevation value. A step of creating contour data representing contours by connecting the contours, and a step of creating plan view information capable of displaying contours visually recognizable by the naked eye from the contour data. How to create source coordinate information. 2. The three-dimensional coordinate information related to terrain and the like according to claim 1, wherein, when the elevation point data is created, a triangular plane group having the actual measurement points as vertices is formed by connecting lines connecting the actual measurement points. How to create 3. The three-dimensional coordinate information relating to terrain or the like according to claim 1 or 2, wherein at the time of creating the contour data, a contour is formed by a spline curve passing through an elevation point corresponding to a predetermined elevation value. How to make. 4. A step of randomly measuring an arbitrary measurement point on a measurement target such as a terrain or the like, and creating actual measurement point data by collecting three-dimensional coordinate data of each actual measurement point; Creating a connecting line that forms a group of polygonal planes, and generating elevation point data by obtaining an elevation point corresponding to a predetermined elevation value on the connection line; and an elevation point corresponding to the predetermined elevation value. A step of creating contour line data representing contour lines by connecting the contour lines; a step of creating plan view information capable of displaying contour lines that can be visually recognized from the contour line data; and a mesh representing grid lines with respect to the plan view information. Overlay the data and calculate the three-dimensional coordinates of the mesh points appearing at the intersections of the grid lines by calculation from the actual measurement point data included in the plan view information to create mesh view information. How to create the three-dimensional coordinate information on the terrain, etc., characterized by comprising a step. 5. A step of randomly measuring an arbitrary measurement point on a measurement target such as terrain and collecting three-dimensional coordinate data of each actual measurement point to create actual measurement point data; and connecting the actual measurement points. Creating a connecting line that forms a group of polygonal planes, and generating elevation point data by obtaining an elevation point corresponding to a predetermined elevation value on the connection line; and an elevation point corresponding to the predetermined elevation value. A step of creating contour line data representing contour lines by connecting the contour lines; a step of creating plan view information capable of displaying contour lines that can be visually recognized from the contour line data; and a mesh representing grid lines with respect to the plan view information. A step of creating mesh diagram information by superimposing data and calculating three-dimensional coordinates of mesh points appearing at intersections of grid lines by calculation from elevation points included in the plan view information How to create the three-dimensional coordinate information on the terrain, etc., characterized in that it comprises an. 6. A step of randomly measuring an arbitrary measurement point on a measurement target such as a terrain and collecting the three-dimensional coordinate data of each actual measurement point to create actual measurement point data; and connecting the actual measurement points. Creating a connecting line that forms a group of polygonal planes, and generating elevation point data by obtaining an elevation point corresponding to a predetermined elevation value on the connection line; and an elevation point corresponding to the predetermined elevation value. Generating contour line data representing the contour lines by connecting the contour line data, creating a plan view information capable of displaying contour lines that can be visually recognized from the contour line data, and forming a grid line with respect to the plan view information. By overlaying the mesh data and obtaining the three-dimensional coordinates of the measured approximate point formed by the intersection of the contour line of the plan view information and the grid line of the mesh data, the measured approximate point data is created. And calculating the three-dimensional coordinates of the mesh points appearing at the intersections of the grid lines by calculation from the actually measured approximate point data to create mesh map information. How to create coordinate information. 7. The method according to claim 4, wherein the three-dimensional coordinates of the mesh points are obtained based on a least squares method.