JPH0552716U - Earth observation device - Google Patents

Abstract

(57) [Summary] [Purpose] A wide area sensor and a high resolution sensor are mounted on the same artificial satellite, and while acquiring a wide area image with the wide area sensor,
An earth observation device aimed at automatically capturing observation areas that require high-resolution images. [Structure] A wide area sensor 6 for observing the forward direction of a satellite is determined, and an observation area for which a high resolution image is required is determined from wide area sensor image data, and a high timing image signal is sent to a high resolution sensor 9 and a movable signal is sent to a movable device 8. It is composed of a calculation device 7 for generation.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a device for acquiring an image of the earth by mounting a plurality of earth observation sensors on an artificial satellite.

[0002]

[Prior Art]

 Conventionally, artificial satellites have been used as an effective means for observing the earth over a wide area. FIG. 4 shows an apparatus for acquiring an image of the earth using a conventional artificial satellite such as the Japanese observation satellite "Momo" or the US observation satellite "LANDSAT". Is an orbiting satellite, 3 is an image data transmission device for transmitting the acquired image data to the ground, 4 is an observation sensor for capturing an image of the earth, and 5 is an arrow indicating the direction of travel of the satellite. It should be noted that, in FIG. 4, there are other devices constituting the artificial satellite, but they are omitted because they are not directly related to the description of the present invention.

Next, the operation will be described. In order to acquire an image of the earth in a conventional earth observation device, the artificial satellite 2 is orbited in advance in a selected orbit, and the scanning width of the observation sensor 4 along the trajectory of the artificial satellite 2 (observation sensor artificial An image corresponding to the visual field width of the ground surface orthogonal to the satellite traveling direction is taken, and the image data is transmitted to the ground by the image data transmission device 3. When trying to acquire a high resolution image with this earth observation device, there is a relationship that the scanning width becomes narrower in inverse proportion to the resolution. For example, the observation sensor's thematic mapper installed in LANDSAT has a resolution of 30 m and a scanning width of Although it is 185 Km, if the resolution is increased to 30 cm, the scanning width becomes 1.85 Km. However, the scanning width is not strictly inversely proportional because it depends on the design of the observation sensor, but the description is omitted because it is not directly related to the present invention.

[0004]

[Problems to be solved by the device]

 Since the conventional earth observation device is configured as described above, it was extremely difficult to put it into practical use because the scanning width was too narrow to acquire a high resolution image of the required observation area. When the required observation area is known in advance, the observation area position is commanded from the ground to the earth observation device of the artificial satellite, the observation sensor 4 is set to high resolution, and a device that can move the direction of the field of view is added to achieve high resolution. Although it may be possible to obtain images, when the pointing accuracy of the observation sensor 4 is estimated, there are problems such as difficulty in achieving the attitude control accuracy and orbit control accuracy of the satellite 2 installed at about 0.01 °. It was

The present invention has been made to solve the above problems, and an object thereof is to obtain an earth observation apparatus capable of acquiring a high resolution image of a necessary observation area.

[0006]

[Means for Solving the Problems]

 The earth observing device according to the present invention is equipped with a wide area sensor and a high resolution sensor on the same artificial satellite, observes the area ahead of the direction of travel of the artificial satellite with a wide area sensor, and acquires high resolution images with an additional computing device. It determines the required position and adds a high-resolution sensor. The movable device changes the field of view to acquire a high-resolution image.

[0007]

[Action]

 In the earth observation device according to this invention, the wide area image data acquired by the wide area sensor is sequentially compared with the target identification parameter stored in advance, and when it is determined that high resolution imaging is necessary, the observation position is calculated from the collation pixel address of the wide area image data. Then, the direction of view of the high-resolution sensor can be changed by the corresponding movable signal and imaging timing signal to obtain a high-resolution image of the required observation area.

[0008]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 to 5 are the same as those of the conventional device. 6 is a wide area sensor that performs wide area observation in front of the satellite traveling direction 5, 7 is a high resolution sensor that performs high resolution observation, 8 is a movable device that changes the direction of the visual field of the high resolution sensor, and 9 is an image of the wide area sensor 6. It is an arithmetic unit that determines a region where a high-resolution image is required from data, calculates the image capturing timing of the high-resolution sensor 7 and the direction of the movable unit 8 that changes the direction of the visual field, and generates respective signals.

FIG. 2 is a conceptual diagram of an embodiment of the present invention, in which 10 is an observation area and pixels scanned by the wide area sensor 6, 11 is an arrow indicating a scanning width, and 12 is a traveling direction of the artificial satellite 2. An arrow indicating the scanning direction, 13 is a target identification area for which a high-resolution image is required, and 14 is an arrow indicating the movement of the high-resolution sensor 9 to change the direction of the visual field.

FIG. 3 is a flowchart showing the operation of the arithmetic unit 7. Reference numeral 15 is an image data input section of the wide area sensor 6, 16 is an image processing section for processing the wide area sensor image data, and 17 is an attitude signal of the artificial satellite 2. Reference numeral 18 denotes a target discriminating unit for discriminating an area where a high resolution image is required in an image acquired by a wide area sensor, 19 is a portion for discriminating a high resolution image is required, and 20 is a photographing timing of the high resolution sensor 9 from the target discriminating area. A geometric conversion calculation unit for calculating a movable angle for changing the visual field direction of the high resolution sensor 9, 21 is a photographing timing signal generation unit of the high resolution sensor 9, and 22 is a movement signal generation unit for the movable device 8.

In the above-described embodiment, a wide area image is taken by the wide area sensor 3 arranged on the artificial satellite 2 toward the front in the traveling direction 5, and the image data is input to the arithmetic unit 7. As shown in FIG. 3, the calculation device sequentially compares the wide area image data with the target parameter stored in advance in the target identification unit 18, and if the determination unit 19 determines that high resolution imaging is required, the conversion unit Calculation is performed at 20. There is an image processing unit 16 for processing image data in the meantime, but it is omitted because it is not directly related to the present invention. As shown in FIG. 2, the geometric transformation calculation unit 20 calculates the movable angle and the photographing timing of the high resolution sensor 9 corresponding to the scanning address 11 and the scanning direction 12 at the pixel address of the wide area sensor image, and the movable signal generation unit 22. A movable signal is generated from the movable angle calculation data, and a photographing timing signal is generated from the photographing timing signal generation unit 21 from the photographing timing calculation data. A movable signal is input to the movable device 8 to operate it, and the field of view of the high-resolution sensor 9 is directed so as to be in the target discrimination region. When the artificial satellite is located in the target discrimination area, the high-resolution sensor is activated by the imaging timing signal to capture a high-resolution image. The wide area image data and the high resolution image data are transmitted to the ground by the image data transmission device 3.

Example 2. In the first embodiment, the target discriminating unit 18 determines the target discriminating area 13 for which a high resolution image is required by collating with the target discriminating parameter stored in advance, but in the present embodiment, the wide area sensor 3 is used as a multi-spectral band optical sensor. Then, the target discriminating unit 18 is made to store a spectrum and a level for eye marker discrimination and a combination of a plurality of spectra, and the multiband spectral optical sensor image data is collated to judge the target discriminating area 13. did.

Example 3. In the first embodiment, the wide area sensor 3 is used as an optical sensor in the present embodiment, and a two-dimensional pattern for target identification is stored in the eye mark identifying unit 18 and is compared with the secondary image of the optical sensor. I made it work.

Example 4. In the first embodiment, the same applies to the case where the wide area sensor 3 is a microwave radar in the present embodiment and a two-dimensional pattern is stored in the target identifying section for target identification and collated with the two-dimensional image of the microwave radar. I made it work.

Example 5. In the first embodiment, in this embodiment, the wide area sensor 3 is used as a microwave radar, and the target discriminating unit stores the reflection level of the microwave radar for target discrimination, and collates it with the image data of the microwave radar. The same operation was performed.

[0016]

[Effect of the device]

 As described above, according to the present invention, the forward direction of the artificial satellite is observed by the wide area sensor, the target identification area in it is automatically determined, and the high resolution image of the necessary area is acquired by the high resolution sensor. With this configuration, it is possible to use a sensor with a narrow scanning width but high resolution.In addition, in the conventional satellite of the earth observation device, the view direction of the observation sensor changes due to attitude changes and orbit changes, and the observation position is changed. Although there was a problem of misalignment, this earth observation device has the effect of avoiding the above problem because only the relative accuracy of the high-resolution sensor and the wide-area sensor in the direction of the field of view is the main cause of the displacement of the observation position. ..

[Brief description of drawings]

FIG. 1 is a block diagram showing an earth observation apparatus according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of an embodiment of the present invention.

FIG. 3 is a flowchart of an arithmetic unit according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional earth observation device.

[Explanation of symbols]

 1 Earth 2 Artificial satellite 3 Image data transmission device 4 Observation sensor 5 Arrow indicating the direction of travel of artificial satellite 6 Wide area sensor 7 Computing device 8 Mobile device 9 High resolution sensor 10 Observation area and pixel 11 Arrow indicating scanning width 12 Scanning direction Shown arrow 13 Target identification area 14 Arrow indicating movement 15 Input section 16 Image processing section 17 Artificial satellite attitude signal 18 Target identification section 19 Judgment section 20 Geometric transformation calculation section 21 Imaging timing signal generation section 22 Movable signal generation section

Claims (4)

[Scope of utility model registration request] 1. An earth observation apparatus for mounting an earth observation sensor on an artificial satellite to acquire an image of the ground surface, and a wide area sensor for scanning an artificial satellite over a wide area to acquire an image,
A high-resolution sensor that acquires a high-resolution image, a movable device that moves the visual field direction of the high-resolution sensor, and an arithmetic device that gives a movable signal to the movable device are provided, and the visual field of the wide-area sensor is in front of the traveling direction of the artificial satellite. The image data acquired by the wide area sensor is input to the arithmetic unit,
The image data is collated by the target identification parameter stored in advance in the arithmetic unit, the visual field target position corresponding to the pixel address of the target identified image data is calculated, and the movable signal of the visual field target position is input to the movable device. The earth observation apparatus is characterized in that the high resolution sensor arranged from the area directly below the artificial satellite toward the rear in the traveling direction is directed to the target area to acquire a high resolution image. 2. The apparatus according to claim 1, wherein the wide area sensor is a multi-spectral band optical sensor, and the arithmetic unit stores a spectrum and a level for identifying a target and a combination of a plurality of spectra as a target identification parameter. An earth observing device, characterized in that the target area of interest is determined and a high-resolution image of the target area is acquired by collating with the image data of the multispectral band optical sensor. 3. The apparatus according to claim 1, wherein the wide area sensor is an optical sensor or a microwave radar, and image data of the optical sensor or data of the microwave radar is input to the arithmetic unit to generate a two-dimensional image. Storing a two-dimensional pattern for identifying a target in the arithmetic device as a target identification parameter, collating with a two-dimensional image of the optical sensor to determine a target target area and acquiring a high resolution image of the target area. Earth observation device featuring. 4. A reflection level of a microwave radar for identifying a target is stored as a target identification parameter in the arithmetic unit, and is compared with data of the microwave radar to determine a target target area to determine a target area height. Earth observation device characterized by acquiring high resolution images.