JP2001160133A - Computer mapping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a computer mapping system enabling a user of the computer mapping system, who does not have know-how about the position coordinates of satellite images, to easily handle map information and the satellite images. SOLUTION: This system is provided with a coordinate managing means 300 managing the position coordinates of digitally computerized map information 60, attaches the position coordinates of the same coordinate system handling the information 60 to the satellite images 50 photographed by a satellite by the means 300 and stores satellite images 70 in a file device 500. Thus, it is possible to handle the satellite images on the mapping system without preparing a dedicated satellite image tool or a coordinate converting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer mapping system for processing map information including digitalized attribute information with a computer.

[0002]

2. Description of the Related Art In general, a computer mapping system for processing map information including digitalized attribute information by a computer is well known. Specifically, car navigation systems, water, gas, electricity,
It has been put to practical use in drawing management systems such as telephones.

A computer mapping system usually comprises a database for storing map information including digitalized attributes, and a mapping means for performing a division process using the map information stored in the database. . By using such a computer mapping system, input, edit,
Correction and display can be performed efficiently.

[0004] Such a computer mapping system is described in, for example, Japanese Patent No. 2656489 and Japanese Patent No. 2753226.

On the other hand, in recent years, various uses of satellite images picked up by observation satellites for wide-area observation have been considered.
Conventionally, a dedicated satellite image processing tool has been used as a computer system for processing satellite images.

In this case, the position information of the satellite image is represented by coordinates used in the satellite image processing tool.
For example, each pixel of the satellite image is managed by row / column numbers or (x, y) coordinates. This is described, for example, in Japanese Patent Application Laid-Open No. H11-109003.

[0007] For the distribution of satellite images, a satellite image file is provided in the form of a data file containing only the satellite image in order to minimize the capacity of the satellite image file, and an additional information file is separately provided as necessary. I have to.

[0008]

Conventional satellite image utilization is often aimed at research, investigation and analysis, and is performed by a user having specialized knowledge using a dedicated satellite image processing tool. However, since a large number of commercial satellites are scheduled to be launched in recent years, the number of satellite image users is expected to increase rapidly. Also, computer mapping systems have been widely spread as systems for processing map information and its attribute information, and users are expanding.

[0009] Since the satellite image also includes detailed information of the target area as well as the map information, it is assumed that the user of the computer mapping system often uses the satellite image. However, since the coordinate system for handling the satellite image is different from the coordinate system in the computer mapping system, there is a problem that it is extremely difficult to use the satellite image in the computer mapping system.

For this reason, there is a strong demand for the development of a system that enables a user of a computer mapping system having no special knowledge about the position coordinates of a satellite image to easily handle map information and a satellite image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable a user of a computer mapping system having no special knowledge about position coordinates of satellite images to easily handle map information and satellite images. It is to provide a computer mapping system which can be used.

[0012]

A feature of the present invention is to provide a coordinate management means for managing position coordinates of digitalized map information, and to map a satellite image taken by a satellite by the coordinate management means. The object is to store satellite images in a file device by assigning position coordinates in the same coordinate system for handling information.

According to the present invention, the satellite image is provided with the position coordinates in the same coordinate system as the map information and managed, so that the satellite image can be handled in the same manner as the map information. Users of computer mapping systems who do not have specialized knowledge about can easily handle map information and satellite images.

In particular, according to the present invention, when a user of a computer mapping system receives and uses a satellite image provided with map information and uses the satellite image, the time and effort of the user can be greatly reduced, and the effect is remarkable.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention deals with satellite images picked up by commercial observation satellites whose use is increasing recently, together with map information.
Landsat satellite and SPOT satellite in France are typical examples.

An embodiment of the present invention will be described below.

FIG. 1 shows the configuration of a computer mapping system according to the present invention. The mapping system shown in FIG. 1 enables handling of satellite images without special external coordinate conversion work, like digital map information.

The main components of the mapping system 100 shown in FIG. 1 are a mapping unit 250, a coordinate management unit 300, and a database 500 as a file device.

In this configuration, based on an operation input from the keyboard 20 as an input operation device, the mapping means 250 refers to the data (map information 60 and satellite image 70) stored in the database 500 and obtains necessary information. After performing the processing, it is displayed on the CRT 10.

The satellite image 50 picked up by a satellite (not shown) is read together with the supplementary information 55 via the coordinate management means 300 and subjected to predetermined conversion and position coordinate addition. be registered. The satellite image 70 after the registration can be handled by the mapping means 250 in the same manner as the map information 60.

The outline of the mapping system 100 has been described above. Next, each component will be described.

The mapping means 250 stores the map information 60 stored in the database (file device) 500.
And the satellite image 70 and the like are processed. Mapping means 250
Is to output a map of an area designated and input by the user via the keyboard 20 to the CRT 10 and to overlay display the attribute information of the map information 60. At the time of such a display process, the mutual coordinates of the terrain, boundaries, buildings, and the like (collectively referred to as “features”) on the map are managed by the position coordinates given to the map information (attribute information) 60. Then, a map (thematic map) reflecting the real world is generated.

As a coordinate system for expressing a geographical position, latitude and longitude are typical. In addition, there are several coordinate systems for maps. In creating a map, it is necessary to project a spherical terrestrial portion of the earth onto a plane, so that a unique distortion occurs due to the selected projection method. As the map projection method, there is the Mercator projection method or the like in which the azimuth on the map (the correctness of the positional relationship between east, west, north and south) is guaranteed.

A universal transverse Mercator (UTM) projection, which is an improved version of the Mercator projection, is known as a map projection method employed in a digital map for mapping. The coordinates based on this projection are the UTM coordinate system,
Widely used as a coordinate system in mapping systems.

In the ordinary Mercator projection, the earth surface is projected with the center of the earth as the center of projection on a cylinder which is covered in a north-south direction so as to be in contact with the equator. Therefore, the error in the distance increases as the latitude increases. On the other hand, in the UTM projection, the ground surface is projected on a cylinder which covers the meridian in the east-west direction. At this time, a central meridian is set for each latitude of 6 °, and only a range of longitude of ± 3 ° from this is projected on a cylinder corresponding to each central meridian, thereby suppressing an error. The projection range for each meridian is the zone number (No.1 to No.60)
Is identified by For example, the UTM zone near Japan is No.
52 to No. 55.

The mapping means 250 has not only a display function but also a function of adding and correcting map information and various analysis operations. The results of information processing by these functions are output to a map information database (DB) 6 included in the database 500.
It is stored together with the coordinate information as the map information 60 in 00.

Next, the coordinate management means 300, which is a feature of the present invention, will be described. Coordinate management means 30
0 reads a satellite image 50 managed in a coordinate system different from the coordinate system of the mapping system 100, newly assigns position coordinates that can be handled by the mapping system 100 by coordinate conversion, A satellite image 70 with position coordinates is registered in an image database (DB) 700.

The satellite image 50 is raster-type information in which pixels are arranged in a matrix as shown in FIG. Each pixel has numerical data (referred to as a CCT value, a DN value, or the like) representing the density of brightness, which is the substance of satellite image information, and coordinate information. Generally, these coordinates are not absolute geographic coordinates that uniquely represent a geographical position, but a matrix system (also referred to as an XY coordinate system) that indicates only relative positions between pixels in an image. Can be

When the satellite image 50 is used alone, it is sufficient that only the positional relationship between the pixels can be managed. However, if it is intended to use the map information 60 together with the map information 60, it is indispensable to superimpose the two positions, and it is necessary to add a coordinate system in the mapping system 100 to the satellite image 50.

The procedure for the coordinate management means 300 to give position coordinates to the satellite image 50 will be described with reference to the flowchart of FIG.

The coordinate management means 300 comprises a satellite image reading means 320, a coordinate conversion means 340 and a satellite image registration means 360 as shown in FIG.

The satellite image reading means 320 executes processing in two steps 320 and 324 in FIG. In the satellite image file reading step 322, a file of the satellite image 50 is read. Next supplementary information file reading step 32
In step 4, a process of reading a file of the additional information 55 corresponding to the satellite image 50 is performed. The supplementary information 55 includes the satellite image 50
, The imaging sensor position, the sensor characteristic parameter value, and the like, and in some cases, the position coordinates of the scene center or scene corner of the satellite image 50 are included.

The coordinate conversion means 340 creates or selects a coordinate conversion formula for adding new position coordinates to the satellite image 50 using the supplementary information 55 and the like read by the satellite image reading means 320. Mapping coordinate system reference step 34
In step 2, the type of the coordinate system adopted in the mapping system 100 is referred to from the database 500. A plurality of coordinate systems can be prepared in the mapping system 100 according to the type of the map information 60 on which the mapping is based. However, only one coordinate system is effective for each display.

In the coordinate transformation formula search step 344, a transformation formula from the coordinate system designated by the supplementary information 55 to the coordinate system confirmed to be adopted in the mapping coordinate system reference step 342 is searched. The conversion formula searched here is stored in the database 500, and is, for example, a conversion formula from latitude / longitude coordinates (φ, λ) to UTM coordinates (N, E) as shown in Expression 1. .

[0035]

N = F1 (φ, λ) E = F2 (φ, λ) (Equation 1) where F1, F2: Conversion formula N: Northing (m) in UTM coordinates, E: Easting (UTM coordinates) m), φ: latitude (deg), λ: longitude (deg) The coordinate conversion formulas F1 and F2 are known formulas including the longitude λo of the central meridian and the equatorial radius Re as parameters (for example,
"Earth Observation Data Handbook-Landsat Edition, Revised Edition", Remote Sensing Technology Center, 1990
Year) is used. A conversion formula from UTM coordinates (N, E) to latitude / longitude coordinates (φ, λ) can be used as a known formula.

If a conversion formula is found in the coordinate conversion formula search step 344, the coordinate conversion formula generation step 346 is skipped and the process proceeds to the satellite image registration means 360.

If no usable conversion formula is found in the coordinate conversion formula search step 344, or if the read satellite image 5
If the supplementary information 55 of 0 does not include information on the position coordinates, the coordinate conversion means 340 executes a coordinate conversion formula generation step 346 to generate a new conversion formula.

The coordinate transformation formula generation step 346 is composed of a total of three steps. In the corresponding point setting step 348, the map information 60 including the same area as the imaging range of the satellite image 50 is searched from the map information DB 600. The search at this time is performed based on the information on the place name included in the supplementary information 55, but the search can also be performed manually by inputting from the keyboard 20.

The map information 60 and the satellite image 55 read by the search are subjected to a position matching process, and each overlapping position is moved little by little.
The correlation coefficient between data is calculated. The superimposed position that maximizes the correlation coefficient can be determined as the corresponding position between the two. Set arbitrary multiple points at this overlapping position,
It will be the corresponding point of both.

In addition to the automatic setting of the corresponding points as described above, the satellite image 5
By using 0 and the map information 60, the user can also position the structures such as buildings, bridges, and the like which are characteristic terrain and landmarks as landmarks, and designate corresponding points.

In the conversion formula selection step 350, the corresponding point i (i
= 1, 2, 3, ...) of the satellite image 50 (xi, y
A model of a conversion formula for formulating the relationship between i) and the coordinates (si, ti) of the map information 60 is selected. The model is registered in the database 500 in advance. As a model,
For example, a rubber sheet model or an affine transformation model shown in Expression 2 can be applied.

[0042]

S = a1 · x + b1 · y + c1 t = a2 · x + b2 · y + c2 ... (Equation 2) where a1, a2, b1, b2, c1, c2: Model parameters Conversion equation parameters In the setting step 352, the parameters of the model selected in the previous step are identified by the coordinates (xi, yi) and (si, ti) of the corresponding point. In the example of the affine transformation model shown in Equation 2, in the same manner as the estimation of the partial regression coefficient of the linear multiple regression model, the residual is minimized for a plurality of pairs of (xi, yi) and (si, ti). Parameters a1, a2, b1, b
2, c1, c2 can be identified. By the processing so far, a conversion formula for converting the satellite image 50 into the same coordinate system as the map information 60 used in the mapping system 100 can be prepared.

The satellite image registration means 360 calculates the coordinates of the coordinate system of the map information 60 from the coordinates of each pixel of the satellite image 50 read using the coordinate conversion formula. The calculated coordinate position data is assigned to each pixel as new position coordinates. In the satellite image output step 364 with mapping coordinates,
The satellite image 50 with the converted position coordinates added is registered in the satellite image DB 700 as a satellite image 70 with coordinates.
The satellite image with coordinates 70 is handled by the mapping means 250 in exactly the same manner as the raster format data of the map information 60.

As described above, the coordinate-added satellite image 70 assigned with the position coordinates by the coordinate management means 300 and registered in the satellite image DB 700 can be handled as it is on another mapping system. Therefore, if it is assumed that the satellite image 70 is used in a mapping system, it is more effective to distribute the satellite image 70 with coordinates.

FIG. 4 shows an example of a file format for distributing the satellite image 70 (50). Generally, satellite image 5
In the case of distributing 0, the satellite image file and the supplementary information file related to the coordinates and the like are distributed as separate files. In the satellite image file device 800 according to the present invention, the satellite image data and the coordinate data of each pixel thereof are stored in the same file and distributed as one file.

By configuring the satellite image file device 800 in this manner, the number of distribution files can be minimized, and even in a computer mapping system having no means such as the coordinate management means 300 according to the present invention, an external special Satellite image data can be handled without requiring coordinate transformation.

Next, considering that the handling of the satellite image 70 with coordinates in the mapping system 100 is often performed in combination with the map information 60, both of which have been aligned in advance are collectively distributed. It is more advantageous to do so. FIG. 5 shows an example of a satellite image file format with a map layer.

The satellite image file 900 shown in FIG.
The map information 60 including the information of the same area and the satellite image 70 with coordinates are stored as separate layers. As a result, both the satellite image 70 and the map information 60, which are expected for many mapping system users, can be provided by distributing the minimum necessary files, as well as positioning and coordinate conversion. This eliminates the need for the user to perform complicated processing.

The map information and the satellite image are handled as described above. A coordinate management means for managing the position coordinates of the digitally converted map information is provided. A satellite image is stored in a file device by giving position coordinates of the same coordinate system for handling map information. Therefore, since the satellite image is managed by adding the position coordinates in the same coordinate system as the map information, the satellite image can be handled in the same manner as the map information. Users of computer mapping systems can easily handle map information and satellite images.

In particular, according to the present invention, when a user of the computer mapping system receives and uses a satellite image to which map information is added and uses it, the labor and the like of the user can be greatly reduced, and the effect is remarkable.

[0051]

According to the present invention, since the satellite image is managed by adding the position coordinates in the same coordinate system as the map information, the satellite image can be handled similarly to the map information. A user of a computer mapping system having no special knowledge about the position coordinates of an image can easily handle map information and satellite images.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a coordinate format of a satellite image and map information.

FIG. 3 is a flowchart illustrating processing steps of a coordinate management unit of the mapping system.

FIG. 4 is a diagram showing an example configuration of a satellite image file.

FIG. 5 is a diagram showing another example configuration of a satellite image file.

[Explanation of symbols]

10 CRT, 20 keyboard, 50 satellite image, 5
5: supplementary information, 60: map information, 70: satellite image with coordinates, 100: mapping system, 250: mapping means, 300: coordinate management means, 320: satellite image registration means, 340: coordinate conversion means, 360: satellite image Reading means, 500: database, 600: map information database, 700: satellite image database, 800: satellite image file, 900: satellite image file.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuo Tsutsui 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Omika Works, Hitachi, Ltd. F-term (reference) 2C032 HB03 HB11 HB22 HC05 HC23 5B050 BA02 BA17 EA20 5B075 ND06 ND35 PP02 PQ02 UU13 9A001 JJ11

Claims (5)

[Claims] 1. A computer mapping system for converting map information into digital information and processing it by a computer, comprising: a coordinate management means for managing position coordinates of the digitalized map information; A computer mapping system, comprising: a file device that stores the satellite image by assigning position coordinates in a coordinate system handled by a coordinate management unit; and a mapping unit that performs information processing of the map information and the satellite image. . 2. A file device for assigning and storing position coordinates to digitalized map information, and a file device for assigning position coordinates of the same coordinate system as the position coordinates of the map information to a satellite image taken by a satellite. A computer mapping system comprising: coordinate management means stored in a device; and mapping means for processing the map information and the satellite image stored in the file device and displaying the information on a display device. 3. A file device for assigning position coordinates to digitalized map information and storing it in a hierarchical manner, and assigning position coordinates of the same coordinate system as the position coordinates of the map information to a satellite image taken by a satellite. A computer mapping system comprising: coordinate management means for hierarchically storing the file information in the file device; and mapping means for distributing the map information and the satellite image stored in the file device. 4. A database storing digitally converted map information by assigning position coordinates thereto and storing it in a hierarchical manner, and a coordinate system of a satellite image photographed by a satellite, which is subjected to coordinate conversion, and a position in the same coordinate system as that of the map information. A computer comprising: coordinate management means for assigning coordinates and hierarchically storing the information together with supplementary information in the database; and mapping means for performing information processing of the map information and the satellite image stored in the database. Mapping system. 5. A database in which a plurality of layers of digitalized map information and a plurality of layers of a satellite image photographed by a satellite are provided with the same position coordinate in the same coordinate system and stored, and a satellite photographed by the satellite. Coordinate management means for performing coordinate conversion of an image, giving position coordinates in the same coordinate system as the position coordinates of the map information, and hierarchically storing the additional information and the additional information in the database, and the map information and the satellite stored in the database A computer mapping system comprising: a mapping unit that performs image information processing.