JPH10153949A - Geographical information system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make using data easy by controlling various space graphic information such as map data, picture data with a uniformity method. SOLUTION: Space graphic information such as map data by longitude and latitude, satellite picture data by a projected graphic is stored in a data storing section 21, each region definition of space graphic information is defined by parameters including a projection original point, a projection direction, a field of vision based on a polar coordinate system centering a globe, and stored in a region definition parameter storing section 22. For a definition of a field of vision, as region definition by a field of vision of picture data and region definition consisting of map data divided by longitude and latitude lines are performed by the same parameter, a polar coordinate value of region definition by division by longitude and latitude lines is adjusted and deal with as a field of vision of a projected picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for processing spatial graphic information represented by a geographic information system (GIS), and more particularly to management and use of various spatial graphic information such as map data and satellite image data.

[0002]

2. Description of the Related Art When constructing a practical system based on a geographic information system (GIS), conventionally, map data and image data necessary for the system have been prepared. However, at present, map data is being prepared by computerization, and it is more advantageous to use existing map data when introducing GIS. In addition, there is an increasing need to use various spatial figures in a unified manner, such as superposition of vector map data by latitude and longitude and image data by artificial satellites.

[0003] In spatial graphic information having different creation conditions and specifications, since the original coordinate system and the mesh definition for partitioning the leaves are different, it has not been possible to manage them uniformly until now.

Recently, in order to manage a variety of spatial information such as map information prepared by various organizations, satellite images, raster data including aerial photographs and paper maps, etc., metadata describing an outline of data and usage is described. The movement to add is progressing. In principle, if the format of the metadata is the same, the user can understand how to use the data just by looking at the metadata.

[0005]

SUMMARY OF THE INVENTION The management of various spatial graphic information data summaries and utilization using metadata is still in the stage of studying necessary parameters and has not yet reached practical use.
In addition, only the usage of data can be understood from the metadata, and a data access program according to the usage must be prepared for use.

For example, when it is intended to overlay vector map data described in latitude and longitude with satellite image data, it is important to determine the conditions (projection origin, projection direction, field of view, etc.) of the image data. Become. In general, map data has a coordinate definition or the like clearly defined, but its representation differs depending on the system. Since vector map data described in latitude and longitude and data such as satellite images are managed by different parameters, different program modules are required to use them simultaneously. Even if metadata is used in this way, a conversion routine corresponding to a combination of data types is eventually required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a user-friendly system that unifies and manages a variety of spatial graphic information such as map data and image data, and simultaneously searches and superimposes them, in view of the current state of the art and problems in the prior art. To provide a geographic information system.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide, for example, map data created according to latitude and longitude lines, satellite or aerial image data created according to polar coordinates originating from the viewpoint in a projected figure. In a map information system that accumulates various kinds of spatial graphic information having different coordinate systems and data formats, and manages so that data retrieval of a desired area with respect to arbitrary spatial graphic information is possible, a projection based on a predetermined reference coordinate system is performed. This is achieved by defining an area of each space graphic information by an area definition parameter necessary for a projection view including an origin, a projection direction, and a field of view, and managing various space graphic information by the same parameter that is regarded as a projection graphic.

[0009] The invention is characterized in that an earth center polar coordinate system is used as the reference coordinate system. In the area definition parameter, a polar coordinate value of the map data in the earth-centered polar coordinate system is adjusted in order to correct a distortion of an area definition by latitude and longitude lines of the map data with respect to an area definition by a view of the image data. It is characterized in that a polar offset is included.

The map information system includes: a space graphic data storage means for storing the map data for each area divided by latitude and longitude lines and for storing the image data for each area corresponding to the field of view; Area definition parameter storage means for storing, in a projection origin based on a coordinate system, a projection direction, an area definition parameter necessary for a projection view including a field of view, corresponding to each area of the spatial graphic data,
According to an input value of a search area in which a projection direction and a field of view are designated, a spatial graphic data search means is provided for searching for a relevant area of the definition content by referring to the area definition parameter and extracting spatial graphic data of the relevant area. It is characterized by.

The spatial graphic data search means represents the search area by a set of cubes, and sequentially between each cube and each area defined by the area definition parameter.
It is characterized in that the presence or absence of the intersection is determined, and the area number of the area with the intersection is listed as the inspection area.

[0012] A coordinate system conversion means for converting the space figure data corresponding to the search area into a display coordinate system (pixel coordinates) and displaying it on a screen is provided.

Further, in an embodiment in which a vector map is superimposed on a satellite image, the map information system converts each constituent point in the map data of the search area into a polar coordinate value in the earth center polar coordinate system, and performs an earth center orthogonalization. Coordinate conversion means for converting the image data into polar coordinate values corresponding to the projection of the image data via a coordinate system, and converting the polar coordinate values into pixel coordinates of an image is provided. It is characterized in that it can be displayed.

According to the present invention, since the definition of the map data and the definition of the image data are performed by using unified parameters, the image data and the map data can be searched or overlapped by the same program module.

Referring to FIGS. 2 to 6, the principle of the unified management of the present invention will be described with reference to map data and satellite images.

FIG. 2 shows that both satellite images and map data can be represented by projection. If the projection origin, the projection direction, the field of view, and the like are known, it is possible to determine which point the image data represents. When this is applied to a map, the map can be viewed as a projection of the earth's surface from the center of the earth.

The coordinate system shown in FIG. 1 uses polar coordinates Σ (r, λ, ψ) centered on the earth, where r is the distance from the earth radius,
λ is defined as longitude and ψ is defined as latitude. Also, the x axis is in the direction of longitude 0 degrees on the equator, the y axis is in the direction of 90 degrees east longitude, and z is
Take the axis toward the North Pole. If the projection origin is defined in this coordinate system, it will be (r, λ, ψ). The position of the satellite S, that is, the photographing origin of the satellite image is (Sr, Sλ, Sψ). In the case of a map, the shooting origin is (0, 0, 0) at the center of the earth.

In the present invention, the reference coordinate system is an earth center coordinate system, and the earth center polar coordinate の in a polar coordinate format frequently used in a projected figure is preferable. However, in principle, it is also possible to use an earth-centered rectangular coordinate system.

FIG. 3 is an explanatory diagram of the projection direction. The projection direction is parallel to the coordinate system of FIG. 2, and a coordinate system Σ ′ (r ′, λ ′, ψ ′) in which only the origin is translated to the projection origin is used. Since the distance in the projection direction is unnecessary, the projection direction is represented by (λ ′, ψ ′).

FIG. 4 shows an explanatory view of the field of view. The illustrated coordinate system Σ * (x *, y *, z *) is a coordinate system obtained by transforming the x * axis so as to match the line of sight and then transforming the image so as to face upward. Here, α and β indicate the viewing angles on the projection plane. If it is a satellite image, bitmap data is projected on the projection plane. The number of pixels in the horizontal direction of the bitmap is Mx, and the number of pixels in the vertical direction is My.

FIG. 5 is an explanatory diagram showing the difference between the area division by the longitude and latitude lines and the field of view of the projected image. In the case of general image data such as a satellite image, the field of view can be correctly defined by the method of FIG. If this is applied to the definition of the boundary of map data by latitude and longitude lines, the distortion will be extremely close as shown in FIG.

Therefore, before defining the field of view, the polar offset γ is once added in the latitude direction of the polar coordinates. By this operation, the field of view β in the latitude direction is expressed as γ ± β. When the field of view is defined thereafter, the field of view α in the longitude direction is defined by the latitude of γ−β and the latitude of γ + β.
The distortion as shown in (c) can be expressed. However, since the polar coordinate offset γ is still added and the center of the area delimited by the field of view is shifted by γ from the projection direction,
Reverse rotation is performed by the amount of the polar coordinate offset γ.

According to this correction, when γ is ψ ′, FIG.
The field of view is defined in the state of (a), and the boundary can be divided by latitude and longitude lines as shown in FIG. When γ = 0, FIG.
The field of view is defined in the state of FIG. 5B, and represents the field of view of the image data as shown in FIG.

FIG. 6 shows the rotation of the coordinate system and the depth of field. Image data is not always north up. Therefore,
The rotation conversion of δ around the x * axis is enabled. In addition, if the map data is treated as a figure projected on the backside of the ground, the left and right sides of the map that is normally used are inverted, so correction is performed by adding an inversion parameter ε.

Furthermore, since the area is defined to infinity only by the projection direction, the maximum value h2 and the minimum value h1 of the depth of field are added in order to limit the area where valid data exists. The depth of field h indicates the maximum and minimum heights in the map data.

Summarizing the parameters described above,
Projection origin (r, λ, ψ), projection direction (λ ′, ψ ′), field of view (α, β), number of pixels (Mx, My), polar coordinate offset (γ), coordinate rotation angle (δ), inversion parameter (Ε), depth of field (h1, h2).

By using these parameters, it is possible to handle both image data from a satellite or the like, which is originally a projected figure, and map data based on latitude and longitude, as projected figure data in a polar coordinate system centered on the earth. And can be displayed.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a functional block diagram showing a configuration of a geographic information system according to one embodiment of the present invention. This system is composed of a computer device, and includes an arithmetic processing device 1, a storage device 2, a data input device 3 such as a keyboard and a mouse,
It comprises a display device 4 such as a CRT or LCD.

The arithmetic processing unit 1 has an area determining means 11, a data selecting means 12, an information obtaining means 13 and a coordinate converting means 14 as functions unique to the present system.
Similarly, the storage device 2 includes a space graphic data storage unit 21, an area definition parameter storage unit 22, and a system information storage unit 2.
Three.

The area determining means 11 determines an area to be processed based on an input from the data input device 3. The data selection unit 12 determines whether data exists in the area based on the data in the area definition parameter storage unit 22. The information acquisition unit 13 acquires only necessary information from the space graphic data storage unit 21 based on the result of the data selection unit 12. The coordinate conversion means 14 performs coordinate conversion of the space information obtained from the information acquisition means 13 based on the information from the area definition parameter storage unit 22 and the system information storage unit 23, adapts the space information to the display coordinate system, and The data is output to the device 4.

The space graphic data storage unit 21 stores, for example, map data, image data, spatial information such as an event occurrence location such as weather information and an object location. The area definition parameter storage unit 22 stores area definition parameters, notes, and the like for each figure. The system information storage unit 23 stores system information,
Stores the system coordinate system definition, etc.

In the following, based on an example of a vector map described by a satellite image and longitude and latitude coordinates, a unified management and utilization method of different spatial graphic information will be described. The bit map of the satellite image and the vector data of the vector map are stored in the space graphic data storage unit 21. These area definition parameters for determining the area of the actual data are stored in the area definition parameter storage unit 22 from the input device 3 via the area determination means 11. At this time, the same region number n is assigned to the region definition parameter of the storage unit 22 corresponding to the actual data of the storage unit 21. In addition to the area number, a projection time, a data format definition, a comment, and the like can be added as the management information.

FIG. 7 is a configuration diagram of the area definition parameter storage unit, showing the contents of the area definition parameters of the vector map and the satellite image to be used. The area number of the vector map is Vn, and the area number of the satellite image is Sn.

Description will be made from the area definition parameters of the vector map. Since the projection origin (r, λ, ψ) is the center of the earth, it is (0, 0, 0). The vector map is composed of two meridians λmin, λmax and two parallels ψmin, ψmax
The projection direction (λ ′, ψ ′) is represented by Formula 1 when the vector map is located at the center point of the existing area when the vector map is located in the area divided by.

[0035]

Vλ ′ = (λmin + λmax) / 2 Vψ ′ = (ψmin + ψmax) / 2 The field of view (α, β) represents the extent of the area in the longitude and latitude directions, and is therefore expressed by Equation 2.

[0036]

Vα = (λmax−λmin) / 2 Vβ = (ψmax−ψmin) / 2 The number of pixels (Mx, My) is determined by the accuracy of the vector map. For example, the coordinate value of the vector map is in the x direction, y
If both directions are represented by values from 0 to 10000, VMx = 10000 and VMy = 10000.

Since the vector map divides the area by latitude and longitude, the field of view (α, β) is bent along the latitude and longitude lines as shown in FIG. For this reason, the area cannot be correctly represented by using the same method as the normal photographic projection. In this embodiment, the polar coordinate system is rotated by the offset γ before the conversion into the rectangular coordinates. Therefore, the converted polar coordinate values are corrected by the offset γ. With this correction, when Vγ = Vψ ′, boundary division can be performed using longitude and latitude lines as shown in FIG.

In a vector map, the north is always up, so
The coordinate rotation angle δ = 0. On the other hand, since the projection on the vector map is to see the ground from the back side, the map is in a left-right inverted state with respect to a normal map. For this correction, the inversion parameter ε is used, and Vε = −1. Further, since the information represented by the vector map is from the ground surface to the maximum elevation in the area, the depth of view h is the radius R of the earth and the maximum elevation Vd in the area.
And Vh1 = R and Vh2 = R + Vd.

Next, the area definition parameters of the satellite image will be described. In the satellite photograph taken from satellite S,
The projection origin (r, λ, ψ) is the position of the satellite S (Sr, Sλ, S
ψ). If the vehicle is flying at the position of the sky Sh on the ground surface, Sr = R + Sh.

The projection direction (λ ′, ψ ′) is the imaging direction (Sλ ′, Sψ ′) from the satellite S. For example, when looking at the ground surface directly below, it is expressed by Equation 3.

[0041]

Sλ ′ = Sλ + 180 ゜ Sψ ′ = − Sψ The field of view (α, β) is determined by the specifications of the satellite S. For example, if the viewing angle of the satellite is 1 degree, Sα = 1 °, Sβ
= 1 °.

The number of pixels (Mx, My) is determined by the resolution of the satellite. For example, if the satellite image is 5000
If the pixel is composed of 3000 pixels in the y direction, SMx = 5000 and SMy = 3000.

A satellite image is handled as a projection image itself when used. Therefore, there is no need to adjust the field of view unlike the vector map, and the parameter γ becomes 0. However, since the satellite image does not always have north at the top, the coordinate rotation angle parameter δ is the inclination Sδ of the satellite image.

Since the projection on the satellite image looks at the ground surface from the front side, it does not become a left-right inverted state unlike the vector map, and the parameter ε becomes 1. Also, since the information shown in the satellite image is from the projection origin to the ground surface, the depth of field h
Is the maximum distance Sd to the ground surface, and Sh1 = 0, S
h2 = Sd.

For these parameters, in consideration of expandability, only a keyword is set using a structure of a text file or the like, and a metadata format that describes what values the item indicated by the keyword takes is described. Is also good. The advantage of using a metadata format is that
It has a high degree of freedom, such as being easy to respond to item changes. For example, different structures can be mixed depending on the meaning of the keyword, and there is no need to write items that need not be described.

Next, a method of selecting data necessary for calculation (search) and display using the above-described region definition parameters will be described. For example, in order to superimpose and display a satellite image and a vector map, from the data input device 3, the satellite position (Sr, Sλ, S 、), direction (Sλ ′, Sψ ′), field of view (Sα, Sβ), depth of field ( (Sh1, Sh2), and obtains vector map data corresponding to the corresponding satellite image data.

FIG. 8 shows a processing flow by the data selection means. The data selection unit 12 acquires the search area input from the input device 3 (S101), and represents this search area as a set of a plurality of cubes (S102). Next, the area definition parameters are fetched one by one from the area definition parameter storage unit 22 in the order of the area number (S103), and whether each cube of the search area intersects with the area of the area number n specified from the area definition parameter is determined. Is determined (S104 to S1).
06).

If it is determined in step S105 that they intersect, the area number n of the area used for the determination is stored in the area number list (S107), and when all area definition parameters have been determined (S108). ), And passes the area number list to the information acquisition unit 13 (S109).

FIG. 9 is an explanatory diagram of the area search. AD
Is an example in which an area corresponding to the area definition parameter is searched and a direction from the point P to 1 is searched as a search area. Since there is a depth of field h, areas A, B, and C intersect, and area D does not intersect.

As described above, in the data selection processing of the present embodiment, by listing, among the n definition areas of the area definition parameters, those that partially include the input search area, all the data are obtained. Definition parameters required for processing can be efficiently acquired without accessing. Also, by representing the search area by a set of cubes, the intersection determination process can be simplified. At this time, as the cube is made finer, the determination accuracy is improved, and the search area is not overlooked. However, since the determination process takes time, the degree of subdivision is optimized according to the purpose of use.

The data acquisition means 13 is a data selection means 1
2 to obtain an area number list. Since all the actual data is managed by the area number n, the actual data can be specified from the area number n. Therefore, actual data is obtained based on the area number list and sent to the coordinate conversion means 14. In this way, it is possible to select only the leaf data necessary for computation and display processing from among many leaflets having an irregular mapper.

Next, a method of converting the actual data extracted by the data acquisition means 13 into display coordinates using the area definition parameters will be described. In the process of converting the coordinate system of the actual data to the display coordinate system via the earth center coordinate system or the like, parallel movement and rotation of the coordinate system are frequently used. In this embodiment, a homogeneous coordinate transformation matrix used in dynamics is used. The homogeneous coordinate transformation matrix is a 4 × 4 matrix obtained by one-dimensionally extending a simple 3 × 3 primary transformation matrix in three dimensions for translation, and is expressed by Equation 4.

[0053]

(Equation 4)

Here, M in (4-1) has a general form.
Mo (x, y, z) in (4-2) is a translation to (x, y, z). (4-3) Mz (θ) is θ rotation about the z axis, (4-4) My (θ) is θ rotation about the y axis,
Mx (θ) in (4-5) is θ rotation about the x-axis.

As an example, the earth center coordinate system Σ (x, y,
z) is converted into a coordinate system Σ ′ ″ (x ′ ″, y ′ ″, z ′ ″) in which the x ′ ″ axis is matched with the direction of the line of sight from the satellite. Since the x-axis is transformed into the x ′ ″-axis, the transformation into the coordinate system Σ ″ ″ can be said to be the transformation that makes the x-axis coincide with the line-of-sight axis.
This is realized by the following three steps.

The first step is a coordinate system transformation for moving the origin of the earth center coordinate system に to the satellite position (Sx, Sy, Sz). This transformation is a parallel move, and M0 (S
x, Sy, Sz). As a result, the coordinate system Σ is converted into the coordinate system Σ ′ (x ′, y ′, z ′) in FIG.

In the second step, the x 'axis is set to (x' so that the x "axis obtained by converting the x 'axis of the coordinate system Σ' exists in a plane including both the line-of-sight axis and the z 'axis. −y ′) is a coordinate system transformation that rotates on the plane, and considering rotation only on the (x′−y ′) plane, the x ″ axis is in a plane that includes both the viewing axis and the z ′ axis. , A λ ′ rotation about the z ′ axis may be performed. As shown in FIG. 10, the x ″ axis, y ″ axis, z ′
The coordinate system Σ ″ defined by the axis is a coordinate system obtained by rotating the coordinate system Σ ′ by λ ′ around the z ′ axis, and the transformation is represented by Mz (λ ′).

The third step is a coordinate system conversion for making the x "axis of the coordinate system Σ" coincide with the viewing direction. Since the x ″ axis is in a plane that includes both the line-of-sight axis and the z ′ axis, in order to make the x ″ axis coincide with the line-of-sight direction, a rotational transformation on the (x ″ −z ″) plane, ie, y ″ FIG. 11 shows a ψ ′ rotation about the y ″ axis, and this transformation is represented by Mz (ψ ′).

To summarize the above three steps, the transformation for making the x-axis coincide with the line of sight can be summarized into one transformation matrix M, and is expressed by Equation 5.

[0060]

M = My (ψ ′) · Mz (λ ′) · Mo (S
(x, Sy, Sz) Next, coordinate conversion for superimposing a vector map on a satellite image will be described. Here, since the purpose is to superimpose the vector map on the satellite image, the vector map is converted into the display coordinate system. Since the satellite image has the same coordinate system as the display coordinates, there is basically no need for conversion.

FIG. 12 shows a flow of a coordinate transformation method by the coordinate transformation means. First, vector map data is obtained (S201), and pixel coordinate values (VPMx, VPMy) of one of the constituent points of the vector map data are obtained (S201).
202). Next, the coordinate system is converted into a polar coordinate system of a coordinate system V * corresponding to the projection of the vector map coordinates (S203).

The x * axis in this polar coordinate system is in the line of sight of the vector map, as shown in FIG. 4, and points from the center of the earth to the center of the vector map area. The views Vα and Vβ are proportional to the number of pixels VMx in the horizontal direction and the number of pixels VMy in the vertical direction of the map, respectively. Therefore, VPMx, VPMy
To the polar coordinate values (VPγ *, VPλ *, VP}
VPλ * and VPψ * of the components converted into
Required by

[0063]

VPλ * = (VPx−VMx / 2) × 2Vα / VMx VPψ * = (VPy−VMy / 2) × 2Vβ / Vmy Also, since the vector map is on the earth surface, VPr * is the radius R of the earth. And VPr * = R.

Although this embodiment shows an example of conversion of a vector map, Pr * can also be represented by a function of Pλ * and Pψ * in a satellite image, and the satellite image can be displayed in another display coordinate system, for example, a vector map. It is possible to convert to the coordinate system of

Next, γ is added to the polar coordinates VPψ * of the VΣ * coordinate system.
An offset (Vψ ') is added (S204). This makes it possible to match the field of view with the longitude and latitude lines. Also, to correct left-right inversion when projecting from behind,
Multiply the polar coordinates VPλ * by the inversion parameter Vε.

Next, the polar coordinates (VPγ *,
VPψ *, VPλ *) is converted into a rectangular coordinate system of the VΣ * coordinate system according to Equation 7 (S205).

[0067]

VPx * = VPr * · cosVPψ * · cosVPλ * VPy * = VPr * · cosVPψ * · sinVPλ * VPz * = VPr * · sinVPψ * Next, from the VΣ * coordinate system, x ′ ″ The conversion to the coordinate system VΣ ″ with the axis coinciding with the viewing direction is performed using the matrix of Expression 8 (S206). This transformation returns -N to the north pole over the image by rotating -Vδ about the x * axis.
By rotating by −Vγ around the y ′ ″ axis, the shift of the center axis due to the addition of the γ offset is corrected.

[0068]

M = My (−Vγ) · Mx (−Vδ) Next, a transformation is performed from the rectangular coordinate system of VΣ ″ to the earth center coordinate system （(S207). Since this is a system, there is no difference in the coordinate system between the vector map and the satellite image, and the vector map and the satellite image can be represented by the same symbol 。.

This conversion is an inverse conversion of the conversion for making the x-axis coincide with the line of sight, and is based on the conversion matrix of Expression 9. That is,
Rotate -V '' around y '"axis and around z' axis-
Perform Vλ 'rotation and move parallel to the center of the earth.

[0070]

M = Mo (0,0,0) · Mz (−Vλ ′) ·
My (−Vψ ′) As a result, one pixel of the vector map data is expressed in the earth center coordinate system.

Next, the x-axis of the earth center coordinate system Σ is converted into a coordinate system SΣ ″ that matches the line of sight of the satellite image (S208). Is performed using a matrix of Equation 10.
Translate the origin to the satellite position (Sx, Sy, Sz),
Perform Sλ ′ rotation about the z axis and perform S ′ ′ rotation about the y ″ axis.

[0072]

M = My (SＭ ′) · Mz (Sλ ′) · Mo
(Sx, Sy, Sz) Next, the SΣ ″ coordinate system is transformed into a coordinate system SΣ * corresponding to the projection of the satellite image (S209). This transformation is performed by rotating Sγ about the y ″ axis, The shift of the center axis due to the subtraction of the γ offset is corrected, and the upper side of the image is turned upward by rotating Sδ about the x ′ ″ axis. The conversion is performed using the conversion matrix of Expression 11.

[0073]

M = Mx (Sδ) · My (Sγ) By the way, all the conversions from S206 to S209 are matrix operations, and all parameters are known. This can be combined into a single matrix operation and used for transforming all pixels. Transformation M that combines matrices of equations 8 to 11
all is represented by Expression 12.

[0074]

## EQU12 ## Mall = Mx (Sδ) · My (Sγ) · My (Sψ ′) · Mz (Sλ ′) · Mo (Sx, Sy, Sz) · Mo (0,0,0) · Mz (−Vλ ') My (-Vψ') My (-Vγ) Mx (-Vδ) The coordinate transformation using this matrix is obtained by Expression 13.

[0075]

(SPx *, SPy *, SPz *) T = Ma
11 · (VPx *, VPy *, VPz *) T Next, the rectangular coordinate system of the SΣ * coordinate system is converted into polar coordinates of the SΣ * coordinate system (S210). This conversion is represented by Equation 14.

[0076]

SPr * = √ (SPx * ² + SPy * ² + SPz * ² ) SPψ * = sin ~ ¹ (SPz * / SPr *) SPλ * = tan ~ ¹ (SPy * / SPx *) Next, SΣ * In the polar coordinates of the coordinate system, γ is given by Equation 15
Remove the offset and change the inversion parameter Sε to SPλ *
(S211).

[0077]

SPψ * = SPψ * −Sψ ′ SPλ * = SPλ * × Sε Next, the polar coordinates of the SΣ * coordinate system are converted into pixel coordinates of display coordinates by Expression 16 (S212).

[0078]

SPMx = SPλ * × SMx / 2Sα + SMx / 2 SPMy = SPψ * × SMy / 2Sβ + SMy / 2 As a result, the pixel coordinates (SPM) in the satellite image are calculated.
x, SPMy).

Next, it is determined whether the conversion has been performed at all points of the vector map (S213), and when the conversion of all points has been completed, the conversion result is output and the processing is terminated (S214). By performing the above-described conversion of S202 to S212 for all points of the vector map, a vector map intersecting with the satellite image can be displayed on the satellite image in a superimposed manner.

According to this embodiment, it is possible to handle various spatial information such as map information and spatial information prepared by various organizations, such as raster data including aerial photographs and paper maps, in a unified manner. .

[0081]

According to the present invention, since the area definition of spatial information such as map data and image data is converted into a projected figure using the viewpoint in the center coordinate system of the earth as the projection origin, it is performed.
Various spatial graphic data can be unified and managed. As a result, information retrieval and display can be processed by the same program module, and the system configuration is simple and easy to use. In particular, superimposition of map data and image data, aggregation and analysis of various types of data, and the like can be efficiently processed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a geographic information system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing that map data and image data can be handled with the same parameters on the earth center polar coordinate system.

FIG. 3 is an explanatory diagram showing a definition of a projection direction.

FIG. 4 is an explanatory diagram showing the definition of a field of view.

FIG. 5 is an explanatory diagram showing a difference between a region division by latitude and longitude and a field of view of a projected image.

FIG. 6 is an explanatory diagram showing rotation of a coordinate system and depth of field.

FIG. 7 is a format diagram of an area definition parameter according to one embodiment.

FIG. 8 is a flowchart illustrating a data search method for a designated area according to one embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a depth of field and a search area.

FIG. 10 is an explanatory diagram showing rotation about the z-axis for adjusting the x-axis to the line of sight.

FIG. 11 is an explanatory diagram showing rotation about a y ″ axis for adjusting an x axis to a line of sight.

FIG. 12 is a flowchart showing a coordinate conversion method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Operation processing device, 2 ... Storage device, 3 ... Input device, 4 ...
Display device, 11 area determination means, 12 data selection means, 13 information acquisition means, 14 coordinate conversion means, 21 ...
Space graphic data storage unit, 22... Area definition parameter storage unit, 23.

Claims (7)

[Claims] 1. Map data created according to longitude and latitude lines, satellite or aerial image data created according to polar coordinates whose origin is a viewpoint in a projected figure, and the like.
In a map information system that stores a variety of spatial graphic information with different base coordinate systems and data formats, and manages it so that data retrieval of a desired area for arbitrary spatial graphic information can be performed, a predetermined reference coordinate system is used. It is characterized by defining the area of each spatial figure information by the area definition parameters necessary for the projection view including the projection origin, projection direction, and field of view based on the same, and managing various spatial figure information by the same parameter that is regarded as a projected figure. Geographic Information System. 2. The geographic information system according to claim 1, wherein an earth center polar coordinate system is used as the reference coordinate system. 3. The method according to claim 2, wherein a distortion of an area definition by latitude and longitude lines of the map data with respect to an area definition by a field of view of the image data is corrected.
A geographic information system, wherein a polar offset for adjusting a polar coordinate value of the map data in the earth center polar coordinate system is defined and included in the area definition parameter. 4. It is possible to accumulate map data created in accordance with latitude and longitude lines and spatial graphic data including image data created in accordance with polar coordinates with a viewpoint as an origin in a projected graphic, thereby enabling data search in a desired area. A map information system that manages the map data for each area divided by latitude and longitude lines and the image data for each area corresponding to the field of view; Area definition parameter storage means for storing area definition parameters required for a projection view including a projection origin, a projection direction, and a field of view based on the reference coordinate system for each area of the spatial graphic data; and According to the input values of the search area specifying the direction and the field of view, the area definition parameter is searched for a corresponding area by referring to the area definition parameter. A geographic information system comprising a spatial graphic data search unit for extracting spatial graphic data of a region. 5. The spatial graphic data searching means according to claim 4, wherein the search area is represented by a set of cubes, and the intersection of each of the cubes and each area defined by the area definition parameter is sequentially determined. A geographic information system which determines presence / absence and lists an area number of an area having an intersection as the search area. 6. The geographic information according to claim 4, further comprising a coordinate system conversion unit for converting the space graphic data corresponding to the search area into a display coordinate system (pixel coordinates) and displaying the converted data on a screen. system. 7. Data retrieval and display of spatial graphic data between map data generated as vector data according to latitude and longitude lines and image data generated as digital data according to polar coordinates with the origin being the viewpoint of a projected graphic. In the map information system that manages the map data, the map data is provided for each area divided by latitude and longitude lines, and the image data is stored for each area corresponding to the field of view, Area definition parameter storage means for storing area definition parameters including a projection origin, a projection direction, and a field of view based on the earth-centered polar coordinate system in correspondence with each area of the map data and each area of the image data; Based on the input values of the search area specifying the origin, projection direction, and field of view, the area definition A spatial graphic data search unit for searching for a corresponding area by referring to the parameters and the area definition parameters of the image data, and extracting map data and image data of the corresponding area; and respective constituent points in the map data of the search area Are converted to polar coordinate values in the earth-centered polar coordinate system, converted to polar coordinate values corresponding to the projection of the image data via the earth-centered rectangular coordinate system, and the coordinates for converting the polar coordinate values to pixel coordinates of an image. A geographic information system comprising a conversion unit, wherein image data and map data of the search area can be displayed in a superimposed manner.