JPS63278179A - Earth observing device - Google Patents

Abstract

PURPOSE:To increase the obtaining frequency of a high definition picture and to constitute a picture obtaining system searching a mobile object by a wide area type optical sensor, controlling the visual field direction of a high resolution type sensor immediately at the time of detecting and obtaining an enlarged picture. CONSTITUTION:The image of the earth 1 by the wide area type optical sensor A3 is reproduced in a picture data transmitter 5, a picture data receiver 7 and a passing picture reproducing device 8, displayed on a display or the like to recognize the moving target object visually. At the time of recognizing a current position, a partially enlarged image is immediately obtained by the high resolution type sensor B4. This is executed by transmitting a predetermined signal to the command device 11 of an artificial satellite 2 from the earth station 6 according to a picture obtaining command device 10 by instructing an obtaining position through the display or the like, decoding it by the device 11 and transmitting this command to a visual field direction controller 12 for controlling to direct the visual field direction of the sensor B4 according to the instruction. Thereby, the high resolution picture of the mobile object can be obtained in a real time without wastefulness.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention acquires images of the earth by mounting an optical sensor on an artificial satellite, transmits them to the ground, receives the image data on the ground, and reproduces images of the earth. This relates to a device for

[Conventional technology]

BACKGROUND ART Incoming satellites have been used as an effective means of observing the Earth over a wide area, as seen in the United States' Landsat satellite and Japan's ocean observation satellites.

Figure 2 shows a device that uses conventional artificial satellites to obtain images of the earth. In Figure 9, 111 is the earth, (2
) is an artificial satellite orbiting the earth, (3) is an optical sensor that acquires images of the earth, (5) is an image data transmission device that transmits the images acquired by sensor (3) to the ground, (
6) is the earth station that receives and reproduces image data from the incoming satellite +21, (the sword is the image data receiving device that constitutes the earth station (6), (8) is the image reproducing device, and A is the direction of travel of the satellite. 9
The mouth is the earth direction of the sensor (3). Although FIG. 2 requires other devices 2 in the artificial satellite, such as a power supply device, an attitude control device, a tracking and telemetry command device, a gas jet device, or a structure, these are not directly relevant to the explanation of this invention. Therefore, it is omitted.

In order to obtain an image of the Earth using such a device, the incoming satellite (2) is flown into a pre-selected orbit (usually a sun-synchronous orbit), and the optical sensor A is placed along the earth trace of the incoming satellite. (3) swidth width (the earth image of the middle part of the field of view on the ground surface of the optical sensor perpendicular to the traveling direction A is detected using a CCD, and the data is transmitted to the ground and reproduced by the system shown in Figure 2). That's what we do.

Data is usually transmitted from satellites to the ground using radio waves.

In order to cover a wider area with this artificial satellite, it is necessary to increase the swath width, but this generally results in a decrease in resolution.

The higher the ground resolution, the narrower the swath width.

The image acquisition area will be limited.

[Problem to be solved by the invention 3 When using the above-mentioned device to acquire images when the target area on the earth's surface is dispersed over many areas, if the position is fixed, the acquisition position can be determined in advance by the incoming satellite. Images can be acquired sequentially by commanding . However, when the ground target moves, for example when you want to quickly acquire images of a ship moving in the ocean, it is unknown where the ship has moved from the position that was acquired @ times, so the above method is the same as how many times. Even if an image is acquired when an incoming satellite arrives on Earth Trace, it will not be possible to obtain an image of the ship.

In other words, the utilization efficiency of inbound satellites is that it is necessary to acquire images over a wide range of moving targets.

It must be said that "data processing on the ground" is extremely inefficient and uneconomical.

The present invention was made to solve these conventional problems, and an object of the present invention is to obtain an earth observation device that can acquire high-resolution images while confirming the moving position of a target object in real time.

[Means for solving problems]

The earth observation device according to the present invention uses a wide-area optical sensor and a high-resolution optical sensor to discover the position of a moving object while acquiring images over a wide area with the wide-area optical sensor, and quickly acquires an image with the position enlarged. The aim is to obtain high-resolution images while checking the moving position of a target object in real time by controlling the viewing direction of a high-resolution optical sensor.

[For production]

In this invention, a wide-area optical sensor and a high-resolution optical sensor are mounted on the same artificial satellite, and the wide-area optical sensor is arranged so that the wide-area optical sensor observes the direction perpendicular to the direction of travel, and images are reproduced in real time. Check the current position of the target object.

The position of this target object is transmitted to the satellite, and an image of the specified position is acquired by a high-resolution optical sensor placed so that the field of view is backward relative to the direction of travel, and high-resolution images are displayed while searching for the moving target object. Since it is something to be obtained, the target object of the surface description.

In the case of a ship sailing on the sea, the position of the ship can be searched over a wide range and a high-resolution image of the vicinity of the position can be obtained.

〔Example〕

Figure 1 shows an earth observation device according to this invention.

In FIG. 1, (3) is optical sensor A, which is a wide-area optical sensor, and (4) is optical sensor B, which is a high-resolution optical sensor.

[I7J is a viewing direction control device for varying the viewing direction of optical sensor B (4), (9) is from the reproduced image.

A target position determination device that finds the position to be enlarged using a high-resolution optical sensor, CLI is an image acquisition command device that instructs the high-resolution optical sensor to obtain an image acquisition target position, and OJ) is a visual field that receives commands from the image acquisition command device α1. Directional control device σ2
A command device that sends commands to.

a and b are viewing directions of optical sensors A and B. The rest is the same as the device shown in FIG.

Since the optical sensor A (3) is a wide-area optical sensor, images of the Earth 11) within this range are reproduced by the image data transmission device (5), the image data reception device (7), and the via image reproduction device (8). can. Where the target object has moved in this reproduced image is displayed on a display or the like and visually confirmed. At this time, a computer compares the current image with the previous images of the same ground surface and detects the changes.
The amount of change in a certain area exceeds a predetermined threshold (it may be displayed in multiple stages).
In case.

By using a target position determination device (9) that displays the area on a display or the like, it becomes easy to visually confirm changes in the target position. Next, since the image obtained here has a large swath width, detailed recognition of the target object is often insufficient in terms of 9-resolution, so the current position of the moving target object can be determined using the above method. After checking, optical sensor B
(4) That is, a partially enlarged image is taken using a high-resolution optical sensor. This is done by indicating the acquisition position on a display, etc., and the image acquisition system a1 sends a predetermined signal from the earth station (6) to the command device 0υ of the artificial satellite (2), which is decoded by the command device aυ. , change the viewing direction of optical sensor B (4) as instructed.
This is executed by sending this command signal to the viewing direction control device a2, which controls the direction of the camera.

This viewing direction control can be performed by changing the angle of the mirror or one reflecting mirror of the optical system used in the optical sensor B (4) with respect to its optical axis.

In addition, the time required to acquire and reproduce images of optical sensor A (3), and confirm changes, and the time required for optical sensor B (4)
The incoming satellite (2) flies for the time (several seconds to several tens of seconds) that is the sum of the time required to direct the optical sensor A (3) toward the target field of view (several tens of kilometers to hundreds of kilometers). The viewing direction of optical sensor B (4) is the distance that the above-mentioned artificial satellite flies from the viewing direction of optical sensor B (4). It is necessary to set it so that

This changes the viewing direction of the optical sensor A (3) to the satellite 11.
) Optical sensor A ( 3 ) is attached to the artificial satellite ] 11 so that the viewing direction of optical sensor B ( 4 ) is behind the advancing direction of the artificial satellite 11 ). 4) can be achieved by attaching it to the artificial satellite i11.

Also, Fig. 1 shows other devices that make up the artificial satellite.

For example, a power supply device, a posture control device 9 a position determining device.

Although there are telemetry devices, they are omitted because they are not directly relevant to the explanation of this invention. Furthermore, here, an optical sensor At31. is used as a sensor for earth observation. I would like to explain about Kyugaku Sensor B (4).

This does not preclude mounting other observation sensors, such as synthetic aperture radar, on the same satellite.

If synthetic aperture radar is also used, the influence of clouds, which is a disadvantage of optical sensors, can be eliminated.

〔Effect of the invention〕

As described above, the earth observation device according to the present invention is provided.

Since the moving target object is searched for using a wide-area optical sensor, a wide area can be searched. Furthermore, after specifying the position, it immediately controls the high-resolution optical sensor to take an image of the specified position.

High-resolution images of moving objects can be acquired in real time and without waste, and images with high information value can be acquired more frequently within the life of an artificial satellite, making it possible to construct an economical image acquisition system.

Note that the orbital positions of nine artificial satellites are not only for moving targets as in the above example, but also for fixed targets.

Since the attitude angle has an error, the viewing direction of the optical sensor will deviate from the previously predicted position. is determined only by the relative directional accuracy with respect to the wide-area optical sensor9
It will also be possible to avoid the difficulty of achieving accurate attitude accuracy for artificial satellites.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an earth observation device according to the present invention, and FIG. 2 is a diagram for explaining a conventional earth observation device using an artificial satellite. In the figure, 11) is the earth, (2) is the satellite, and (3)
is optical sensor A, f5+ is image data transmission device, (6)
is an earth station, (7) is an image data receiving device, and (8) is an image reproducing device. FIG. 1 is a diagram for explaining the earth observation device according to the present invention, and (4) is an optical sensor B, αυ
is a command device, a is a viewing direction control device, (9) is a target position determination device, and al is an image acquisition command device. Note that the same or corresponding parts in FIG. 9 are designated by the same reference numerals.

Claims (1)

[Claims] In earth observation equipment that obtains images of the earth's surface by installing optical sensors on artificial satellites, acquiring images of the earth's surface, transmitting them to the ground, and reproducing the images on the ground, narrow-range high-resolution optical sensors and their field of view are used. a wide-area optical sensor arranged such that the direction is in front of the field of view of the optical sensor with respect to the advancing direction of the artificial satellite, an image data transmission device that transmits image data acquired by the optical sensor, and the high resolution An artificial satellite equipped with a viewing direction control device that changes the viewing direction of an optical sensor and a command device that receives and decodes commands from the ground that give instructions to the control device, and receives image data from the image data transmission device. a receiving device for reproducing an image of the output of the receiving device; a target position determining device for detecting a change in the position of a target object using the image reproduced by the reproducing device and finding a partial area to be acquired by an optical sensor; an image acquisition command device that transmits the image acquisition command to the command device based on the output of the target position determination device; the image data receiving device and the image reproduction device reproduce the image of the wide-area optical sensor; From the image, find the partial area that you want to acquire with the high-resolution optical sensor visually or by using a target position determination device, and then set the viewing direction of the high-resolution optical sensor by instructing the viewing direction control device via the image acquisition command device and the command device. An earth observation device equipped with an earth station directed toward a target position.