JP3423848B2 - Geographic information system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatial graphic information processing system represented by a geographical information system (GIS), and more particularly to management and utilization 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 required for the system have been prepared. However, at present, map data is being improved by computerization, and it is more advantageous to use existing map data when introducing GIS. In addition, there is an increasing need for unified use of various spatial figures such as superimposition of vector map data according to latitude and longitude and image data from artificial satellites.

In the spatial graphic information having different creation conditions and specifications, the original coordinate system and the mesh definition for partitioning the map leaf are different, so that it has not been possible to manage them in a unified manner.

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

[0005]

SUMMARY OF THE INVENTION Outline of data of various spatial figure information and management by use metadata are still in the stage of studying necessary parameters and have not yet been put to practical use.
Also, only the usage of the data can be understood from the metadata, and a data access program according to the usage must be prepared when using the data.

For example, when it is attempted to superimpose satellite map data and vector map data described in latitude and longitude, it is important under what conditions (projection origin, projection direction, field of view, etc.) the image data was obtained. Become. Also, in general, map data has a clear definition of coordinates, but the representation differs depending on the system. Since vector map data described in latitude and longitude and data such as satellite images are managed with different parameters, different program modules are required to use them simultaneously. Even if the metadata is used as described above, a conversion routine corresponding to a combination of data types is eventually required.

In view of the current state of the art and problems, the object of the present invention is to manage various spatial graphic information such as map data and image data in a unified manner, and to retrieve and overlay them at the same time, which is convenient. To provide a geographical information system.

[0008]

[Means for Solving the Problems] The above-mentioned object is based on map data created according to latitude and longitude lines, image data such as satellites and aerial photographs created according to polar coordinates with a viewpoint in a projected figure as an origin. In a map information system that stores various spatial figure information with different coordinate systems and data formats, and manages it so that it is possible to retrieve data in a desired area for arbitrary spatial figure information, projection based on a predetermined reference coordinate system This is achieved by defining the area of each spatial figure information by the area definition parameters necessary for the projection diagram including the origin, the projection direction, and the field of view, and managing various spatial figure information by the same parameter which is regarded as the projection figure.

An earth-centered polar coordinate system is used as the reference coordinate system. Further, the region definition parameter adjusts the polar coordinate value of the map data in the earth-centered polar coordinate system in order to correct the distortion of the region definition due to the latitude and longitude lines of the map data with respect to the region definition due to the field of view of the image data. It is characterized by the inclusion of polar offsets.

The map information system has a spatial graphic data storage means for storing the map data for each area divided by a latitude / longitude line and an area for storing the image data for each area according to a field of view, and a predetermined reference. Area definition parameter storage means for storing area definition parameters necessary for a projection drawing including a projection origin based on a coordinate system, a projection direction, and a field of view in correspondence with each area of the spatial graphic data, and the projection origin,
According to the input value of the search area in which the projection direction and the field of view are designated, the area definition parameter is referred to search the area corresponding to the definition content, and the spatial figure data searching means for extracting the spatial figure data of the area is provided. 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 an intersection is determined and the area number of the area having the intersection is listed as the inspection area.

It is characterized in that a coordinate system conversion means for converting the spatial graphic data corresponding to the search area into a display coordinate system (pixel coordinates) and displaying it on the screen is provided.

Further, in the case of the embodiment in which the vector map is superposed on the 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 to obtain an earth center orthogonal coordinate. Coordinate conversion means for converting 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 the image is provided, and the image data of the search area and the map data are superposed. The feature is that it can be displayed.

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

With reference 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 image examples.

FIG. 2 shows that both satellite images and map data can be represented by projection. By knowing the projection origin, the projection direction, the field of view, etc., 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 ground surface from the center of the earth.

In the coordinate system of the figure, polar coordinates Σ (r, λ, ψ) centering on the earth are used, where r is the distance from the earth radius,
Define λ as longitude and ψ 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 east longitude 90 degrees, and z
Take the axis toward the North Pole. Defining the projection origin in this coordinate system gives (r, λ, ψ). The position of the satellite S, that is, the shooting origin of the satellite image is (Sr, Sλ, Sψ). In the case of a map, the origin of photography is the earth center (0,0,0).

The reference coordinate system in the present invention is the earth center coordinate system, and the earth center polar coordinate Σ of a polar coordinate format which is frequently used in projection figures is preferable. However, in principle, it is also possible to use the earth-centered Cartesian coordinate system.

FIG. 3 shows an explanatory view 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 in which the x * axis is transformed so as to match the line-of-sight direction, and then the image is oriented upward. Here, α and β represent viewing angles on the projection surface. If it is a satellite image, bitmap data is projected on the projection surface. 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 latitude and longitude 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. When this is applied to the definition of the boundary of the map data by the latitude / longitude line, the distortion is extremely close as shown in FIG. 5 (c).

Therefore, before defining the field of view, the polar coordinate offset γ is once added in the latitude direction of the polar coordinate. By this operation, the field of view β in the latitude direction is represented as γ ± β. When the field of view is defined after this, the field of view α in the longitudinal 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 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 boundary division can be performed by the latitude and longitude lines as shown in FIG. 5 (c). When γ = 0, FIG.
The field of view is defined in the state of (b) 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. The image data is not always north north. Therefore,
Allows rotation conversion of δ around the x * axis. Further, if the map data is treated as a projected figure on the back side of the ground, the map is normally used and the left and right are reversed, so the correction is performed by adding the reversal parameter ε.

Further, since the area is defined up to infinity only in the projection direction, the maximum value h2 and the minimum value h1 of the depth of field are added to limit the area where the valid data exists. The depth of field h represents 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 the image data of the satellite, which is originally a projected figure, and the map data of the latitude and longitude as projected figure data in the polar coordinate system centered on the earth, and search by the same processing means. Can be displayed and displayed.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. FIG. 1 is a functional block diagram showing the configuration of a geographical information system according to an 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 a region determining means 11, a data selecting means 12, an information acquiring means 13 and a coordinate converting means 14 as functions peculiar to the present system.
Similarly, the storage device 2 includes a spatial graphic data storage unit 21, an area definition parameter storage unit 22, and a system information storage unit 2.
Have three.

The area determining means 11 determines the area to be processed based on the input from the data input device 3. The data selection means 12 determines whether or not the 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 spatial graphic data storage unit 21 based on the result of the data selection unit 12. The coordinate conversion unit 14 performs coordinate conversion of the spatial information obtained from the information acquisition unit 13 based on the information from the area definition parameter storage unit 22 and the system information storage unit 23, adapts the spatial information to the display coordinate system, and displays it. The data is output to the device 4.

The spatial graphic data storage unit 21 stores spatial information such as map data, image data, event occurrence locations such as weather information, and object presence locations. The area definition parameter storage unit 22 stores area definition parameters, notes and the like for each drawing sheet. The system information storage unit 23 stores system information,
Stores the system coordinate system definition, etc.

Below, based on an example of a vector map described by satellite images and latitude and longitude coordinates, a unified management and usage of different spatial figure information will be described. The space map data storage unit 21 stores the bit map of the satellite image and the vector data of the vector map. The area definition parameter that determines the area of these actual data is 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 area number n is given to the area definition parameter of the storage unit 22 corresponding to the actual data of the storage unit 21. In addition to the area number, projection time, data format definition, annotation, etc. can be added as the management information.

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

The area defining parameters of the vector map will be described first. Since the projection origin (r, λ, ψ) is the center of the earth, it is (0, 0, 0). Vector map has two meridians λmin and λmax and two latitude lines ψmin and ψmax
The projection direction (λ ′, ψ ′) when it exists in the area delimited by is expressed by the equation 1 because the vector map is the center point of the existing area.

[0035]

## EQU1 ## V.lamda. '= (. Lamda.min + .lamda.max) / 2 V.psi.' = (. Psi.min + .psi.max) / 2 The field of view (.alpha.,. Beta.) Expresses the longitude and latitude of the region, and is therefore expressed by Formula 2.

[0036]

## EQU2 ## 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 x direction, y
If both directions are represented by values from 0 to 10000, VMx = 10000 and VMy = 10000.

Since the vector map is divided into regions by latitude and longitude, the field of view (α, β) is curved along the latitude and longitude lines as shown in FIG. 5 (c). For this reason, it is not possible to correctly represent the area using the same method as that for normal photographic projection. In this embodiment, the polar coordinate system is rotated by the offset γ before being converted into the rectangular coordinates. Therefore, the converted polar coordinate value is corrected by the offset γ. By this correction, when Vγ = Vψ ′, boundary division by the latitude / longitude line can be performed as shown in FIG.

Since the north is always on the top in the vector map,
The coordinate rotation angle δ = 0. On the other hand, the projection on the vector map looks at the ground surface from the back side, so that it is in the state of left-right reversal from the normal map. The inversion parameter ε is used for this correction, and Vε = −1. Further, since the information represented by the vector map is from the ground surface to the maximum altitude within the area, the depth of field h is the radius R of the earth and the maximum altitude Vd within the area.
Is used, Vh1 = R and Vh2 = R + Vd.

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

The projection direction (λ ', ψ') is the imaging direction (Sλ ', Sψ') from the satellite S, and is represented by the equation 3 if the ground surface directly below is viewed, for example.

[0041]

## EQU3 ## 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) depends on the resolution of the satellite. For example, the satellite image is 5000 in the x direction.
If the pixel is composed of 3000 pixels in the y direction, SMx = 5000 and SMy = 3000.

The satellite image is treated as a projected image itself when used. Therefore, it is not necessary to adjust the field of view unlike the vector map, and the parameter γ becomes 0. However, since the satellite image is not always in the north upward direction, the coordinate rotation angle parameter δ is the inclination Sδ of the satellite image.

Since the projection on the satellite image sees the surface of the earth from the front side, the parameter ε becomes 1 without being in a horizontally inverted state unlike a vector map. In addition, 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, Sh1 = 0, S
h2 = Sd.

With regard to these parameters, in consideration of extensibility, only a keyword is set by using a structure such as a text file, and a metadata format describing what value an item indicated by the keyword takes is used. Good. The advantages of using a metadata format are:
This means that it is easy to handle changes in items and has a high degree of freedom. For example, it is possible to mix different structures depending on the meaning of the keyword, and it is not necessary to write an object that does not need to be described.

Next, a method of selecting data required for calculation (retrieval) and display will be described using the area definition parameters described above. For example, in order to display the satellite image and the vector map in an overlapping manner, the satellite position (Sr, Sλ, Sψ), the direction (Sλ ′, Sψ ′), the field of view (Sα, Sβ), the depth of field (from the data input device 3 are displayed. Sh1, Sh2) is designated to acquire vector map data corresponding to the corresponding satellite image data.

FIG. 8 shows a processing flow by the data selecting means. The data selection means 12 acquires the search area input from the input device 3 (S101), and represents this search area with 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 (S103), and whether or not each cube of the search area intersects the area of the area number n specified by the area definition parameter is determined. Is determined (S104 to S1
06).

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

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

As described above, in the data selection processing of the present embodiment, among the n definition areas of the area definition parameter, the ones that partially include the input search area are listed, so that all the data can be obtained. Definition parameters required for processing can be acquired efficiently without accessing. In addition, the intersection determination process can be simplified by representing the search region by a set of cubes. At this time, the finer the cube, the higher the accuracy of determination, and the more the search area is 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 the data selection means 1
Obtain the area number list from 2. Since all real data is managed by the area number n, the real data can be specified from the area number n. Therefore, the actual data is acquired based on the area number list and sent to the coordinate conversion means 14. In this way, it is possible to select only the data of the leaf necessary for the calculation and display processing from many leaf having the non-regular outline.

Next, a method for 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 from the coordinate system of actual data to the display coordinate system via the earth center coordinate system and the like, translation and rotation of the coordinate system are often used. In this embodiment, a homogeneous coordinate transformation matrix used in mechanics is used. The homogeneous coordinate transformation matrix is a 4 × 4 matrix in which a simple 3 × 3 linear transformation matrix in three dimensions is extended one dimension for translation, and is represented by Formula 4.

[0053]

[Equation 4]

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

As an example, the earth center coordinate system Σ (x, y,
The coordinate conversion for converting z) into a coordinate system Σ '"(x'", y '", z'") in which the x '"axis is aligned with the line of sight from the satellite will be described. Since the x-axis is converted to the x '"axis, it can be said that the conversion to this coordinate system Σ'" is a conversion to match the x-axis with the line-of-sight axis.
It is realized by the following three steps.

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

The second step is to set the x'axis to (x 'so that the x "axis obtained by converting the x'axis of the coordinate system Σ'is present in the plane including both the line-of-sight axis and the z'axis. -Y ') This is a coordinate system transformation that rotates on the plane.Since the rotation only on the (x'-y') plane is considered, the x "axis is in the plane including both the line-of-sight axis and the z'axis. For this purpose, λ ′ rotation around the z ′ axis may be performed. As shown in FIG. 10, x "axis, y" axis, z '
The coordinate system Σ ″ defined by the axes is a coordinate system obtained by rotating the coordinate system Σ ′ about the z ′ axis by λ ′, and the conversion is represented by Mz (λ ′).

The third step is a coordinate system conversion in which the x "axis of the coordinate system Σ" coincides with the line-of-sight direction. Since the x "axis is in a plane including both the line-of-sight axis and the z'axis, in order to match the x" -axis with the line-of-sight direction, a rotational transformation on the (x "-z") plane, that is, y " It is sufficient to perform ψ ′ rotation about the axis, and FIG. 11 shows ψ ′ rotation about the y ″ axis, and this conversion is represented by Mz (ψ ′).

When the above three steps are put together, the transformations for matching the x-axis with the line-of-sight direction can be aggregated into one transformation matrix M, which is expressed by equation 5.

[0060]

[Equation 5] M = My (ψ ′) · Mz (λ ′) · Mo (S
x, Sy, Sz) Next, the coordinate conversion for superimposing the vector map on the 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, basically no conversion is necessary.

FIG. 12 shows the flow of the coordinate conversion method by the coordinate conversion means. First, vector map data is acquired (S201), and the pixel coordinate value (VPMx, VPMy) of one of the constituent points of the vector map data is acquired (S201).
202). Next, it is converted into the polar coordinate system of the coordinate system VΣ * corresponding to the projection of the vector map coordinates (S203).

The x * axis in this polar coordinate system is the line-of-sight direction of the vector map, as shown in FIG. 4, and extends from the center of the earth toward the center of the vector map area. The fields of view Vα and Vβ are proportional to the number of pixels in the horizontal direction VMx and the number of pixels in the vertical direction VMy, respectively. Therefore, VPMx, VPMy
Is the polar coordinate value of the Σ * coordinate system (VPγ *, VPλ *, VPψ
Of the components converted to *), VPλ * and VPψ * are expressed by
Required by.

[0063]

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

Although this embodiment shows an example of vector map conversion, Pr * can be expressed by a function of Pλ * and Pψ * even 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 coordinate VPψ * of the VΣ * coordinate system.
An offset (Vψ ') is added (S204). This allows the field of view to be aligned with the latitude and longitude lines. Also, to correct the left-right reversal when projecting from the back side,
The polar coordinate VPλ * is multiplied by the inversion parameter Vε.

Next, the polar coordinates of the VΣ * coordinate system (VPγ *,
VPψ *, VPλ *) is converted to the Cartesian coordinate system of the VΣ * coordinate system by the equation 7 (S205).

[0067]

VPx * = VPr * · cosVPψ * · cosVPλ * VPy * = VPr * · cosVPψ * · sinVPλ * VPz * = VPr * · sinVPψ * Next, from the orthogonal coordinate system of the VΣ * coordinate system, x ′ ” The conversion to the coordinate system VΣ ′ ″ with the axes aligned with the line-of-sight direction is performed using the matrix of Equation 8 (S206). This transformation returns the top of the image to the North Pole by rotating -Vδ around the x * axis,
By rotating −Vγ around the y ′ ″ axis, the deviation of the central axis due to the addition of the γ offset is corrected.

[0068]

[Formula 8] M = My (−Vγ) · Mx (−Vδ) Next, conversion from the Cartesian coordinate system of VΣ ′ ″ to the earth center coordinate system Σ is performed (S207). Since it is a system, there is no difference in the coordinate system between the vector map and the satellite image, and they can be represented by the same symbol Σ.By passing through this earth center coordinate system, it is possible to convert the vector map and the satellite image.

This conversion is an inverse conversion of the conversion in which the x axis coincides with the line-of-sight direction, and is based on the conversion matrix of equation (9). That is,
Rotate -Vψ 'around y'"axis and rotate around z'-axis
Vλ ′ rotation is performed and parallel movement is performed to the center of the earth.

[0070]

[Equation 9] M = Mo (0,0,0) · Mz (−Vλ ′) ·
My (−Vψ ′) As a result, one pixel of the vector map data is represented by the earth center coordinate system.

Next, the x-axis of the earth-centered coordinate system Σ is converted into a coordinate system SΣ ′ ″ in which the line-of-sight direction of the satellite image is matched (S208). This conversion matches the above-mentioned x-axis with the line-of-sight direction. This conversion is performed using the matrix of Equation 10. First,
Translate the origin to the satellite position (Sx, Sy, Sz),
Sλ ′ rotation is performed around the z axis, and Sψ ′ rotation is performed around the y ″ axis.

[0072]

[Equation 10] M = My (Sψ ′) · Mz (Sλ ′) · Mo
(Sx, Sy, Sz) Next, conversion from the SΣ ′ ″ coordinate system to the coordinate system SΣ * corresponding to the projection of the satellite image is performed (S209). This conversion is performed by rotating Sγ around the y ″ axis. The shift of the central axis due to the subtraction of the γ offset is corrected, and the image is turned upward by rotating Sδ around the x ′ ″ axis. The conversion is performed by using the conversion matrix of Expression 11.

[0073]

## EQU00009 ## M = Mx (S.delta.). My (S.gamma.) By the way, all the transformations from S206 to S209 are matrix operations, and all parameters are known. This can be combined into one matrix operation and used for conversion of all pixels. Transformation M that summarizes the matrices of equations 8 to 11
all is represented by Expression 12.

[0074]

[Expression 12] Mall = Mx (Sδ) · My (Sγ) · My (Sψ ′) · Mz (Sλ ′) · Mo (Sx, Sy, Sz) · Mo (0,0,0) · Mz (−Vλ ') * My (-V [psi]') * My (-V [gamma]) * Mx (-V [delta]) The coordinate conversion by this matrix is obtained by Expression 13.

[0075]

(13) (SPx *, SPy *, SPz *) T = Ma
ll · (VPx *, VPy *, VPz *) T Next, the Cartesian coordinate system of the SΣ * coordinate system is converted into polar coordinates of the SΣ * coordinate system (S210). This conversion is expressed by Expression 14.

[0076]

[Formula 14] SPr * = √ (SPx * ² + SPy * ² + SPz * ² ) SP ψ * = sin ~ ¹ (SPz * / SPr *) SPλ * = tan ~ ¹ (SPy * / SPx *) Next, SΣ * In polar coordinates in the coordinate system, γ
Remove the offset and set the inversion parameter Sε to SPλ *
(S211).

[0077]

[Formula 15] SPψ * = SPψ * −Sψ ′ SPλ * = SPλ * × Sε Next, the polar coordinates of the SΣ * coordinate system are converted into the pixel coordinates of the display coordinates by Expression 16 (S212).

[0078]

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

Next, it is determined whether or not the conversion is performed at all points of the vector map (S213), and if the conversion of all points is completed, the conversion result is output and the processing is completed (S214). By performing the above-described conversion of S202 to S212 for all points of the vector map, it is possible to display the vector map intersecting the satellite image in a superimposed manner on the satellite image.

According to the present embodiment, it is possible to handle a variety of spatial information such as map information, spatial information, raster data including aerial photographs and paper maps prepared by various organizations by a unified method. .

[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 having the viewpoint of the earth center coordinate system as the projection origin,
Various spatial figure 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, it is possible to efficiently process superposition of map data and image data, aggregation and analysis of various data, and the like.

[Brief description of 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-centered polar coordinate system.

FIG. 3 is an explanatory diagram showing the 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 based on longitude and latitude 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 area definition parameters according to an embodiment.

FIG. 8 is a flowchart showing a data search method for a designated area according to an 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 around the z axis for aligning the x axis with the line of sight.

FIG. 11 is an explanatory diagram showing rotation around the y ″ axis for aligning the x axis with the line of sight.

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

[Explanation of symbols]

1 ... Arithmetic 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 ...
Spatial figure data storage unit, 22 ... Area definition parameter storage unit, 23 ... System information storage unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-319984 (JP, A) JP-A-60-15776 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G09B 29/00-29/14 G06T 17/50

Claims (7)

(57) [Claims] And map data created in accordance with claim 1] Coordinates line, the image data from satellite or aerial photographs made in accordance with polar coordinates as the origin viewpoint in projected figure
Land accumulate spatial graphic information, managed so as to enable data retrieval of a desired area for any spatial graphic information including
In the physical information system , the map data is divided into areas divided by latitude and longitude lines.
, And the image data is
The spatial figure information storage means stored in each and the projection origin, projection direction, and field of view based on a predetermined reference coordinate system
Area definition parameters required for the projection including
Area definition parameters to be stored corresponding to each area of shape information
Storage means, processing hand defines the area of each spatial graphic information by the region definition parameter, to not search or overlapped by the same parameter with the spatial graphic information on projected figure
A geographical information system characterized by comprising steps . 2. The geographic information system according to claim 1, wherein an earth-centered polar coordinate system is used as the reference coordinate system. 3. The correction according to claim 2, wherein distortion of the area definition by the latitude and longitude lines of the map data with respect to the area definition by the field of view of the image data is corrected.
A geographic information system wherein a polar coordinate offset for adjusting a polar coordinate value of the map data in the earth-centered polar coordinate system is defined and included in the area definition parameter. 4. Spatial figure data including map data created according to latitude and longitude lines and image data created according to polar coordinates with a viewpoint in a projected figure as an origin is accumulated, and data search of a desired area is possible. In the geographic information system managed as described above, the map data is stored for each area divided by a latitude / longitude line, and the image data is stored for each area according to a field of view. Area definition parameter storage means for storing the area definition parameters necessary for the projection drawing including the projection origin, the projection direction, and the field of view based on the reference coordinate system of the space figure data, and the projection origin and the projection. According to the input value of the search area in which the direction and field of view are specified, the area definition parameters are referenced to search for the corresponding area of the definition contents, and the corresponding area is searched. A geographical information system characterized by comprising a spatial graphic data search means for extracting spatial graphic data of a region. 5. The spatial graphic data search means according to claim 4, wherein the search region is represented by a set of cubes, and the cubes are sequentially intersected with each region defined by the region definition parameter. A geographical information system characterized by determining the presence / absence and listing the area numbers of intersecting areas as the search areas. 6. The geographical information according to claim 4, further comprising coordinate system conversion means for converting the spatial graphic data corresponding to the search area into a display coordinate system (pixel coordinates) and displaying the screen. system. 7. Data search and display of these spatial graphic data, map data created as vector data according to the latitude and longitude lines, and image data created as digital data according to polar coordinates with the viewpoint of the projection figure as the origin. In the geographic information system that manages so as to enable the map data, the map data is stored for each region divided by the latitude and longitude lines, and the image data is stored for each region according to the field of view. An area definition parameter that stores a space graphic data storage means and an area definition parameter including a projection origin, a projection direction, and a field of view based on a polar coordinate system of the earth in association with each area of the map data and each area of the image data. Based on the storage means and the input value of the search area in which the projection origin, the projection direction, and the field of view are specified, the area of the map data is determined. Spatial figure data searching means for searching the corresponding area by referring to the parameter and the area definition parameter of the image data, and extracting map data and image data of the corresponding area, and each constituent point in the map data of the search area. Is converted into polar coordinate values in the earth-centered polar coordinate system, converted into polar coordinate values corresponding to the projection of the image data via the earth-centered Cartesian coordinate system, and the polar coordinate values are converted into pixel coordinates of the image. A geographic information system characterized in that conversion means is provided so that the image data of the search area and the map data can be displayed in an overlapping manner.