JP2765002B2 - Radiometer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiometer, and more particularly to a radiometer mounted on a satellite.

[Conventional technology]

Conventionally, this type of radiometer has a focus position
A method of maintaining a stable focus position with respect to the environment such as temperature, a method of performing focus adjustment based on the data of the movement amount of the focus position with respect to the environment acquired in advance, or an artificial adjustment while observing an image in real time In this method, the focus position is confirmed by statistical processing of image data for different targets.

[Problems to be solved by the invention]

The conventional radiometer described above has a drawback that stability of the focal position cannot be obtained when the environmental conditions are severe or when the focal position fluctuates sensitively to the environment. In addition, there are disadvantages that the accuracy of the environmental characteristic data is not sufficient, the characteristic value changes due to other factors, and a stable good focus position cannot be maintained. Further, there is a disadvantage that it takes a long time to confirm the focal position and, when a shift has occurred, it is not possible to determine whether the shift is before or after.

[Means for solving the problem]

The radiometer of the present invention is a radiometer including a line sensor that images a continuously moving target, and an optical system that forms light from the target on a light receiving surface of the line sensor.
A first transparent plate whose two opposing faces are parallel and can be inserted and removed in the middle of the optical path between the line sensor and the optical system, and can be inserted and removed in the middle of the optical path between the line sensor and the optical system A second transparent plate having two opposing surfaces inclined along the imaging direction of the line sensor, the first transparent plate being inserted into the optical path at the time of imaging, and the second transparent plate being inserted at the time of focus position detection. It comprises a moving mechanism inserted into the optical path, and a rotating mechanism for changing the imaging direction of the line sensor by 90 ° at the time of detecting the focal position.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

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

As shown in FIG. 1, a line sensor 2 for imaging a continuously moving target, an optical system 1 for imaging light from the target on a light receiving surface of the line sensor 2, a line sensor 2 and an optical system 1, And a glass plate 6 as a first transparent plate having two parallel surfaces facing each other, which can be inserted and removed in the middle of the optical path; A glass plate 3 as a second transparent plate whose two surfaces are inclined in a wedge shape along the imaging direction of the line sensor 2,
The moving mechanism 4 inserts the glass plate 6 into the optical path when capturing an image and inserts the glass plate 3 into the optical path when detecting the focal position.
A body case 7 that is housed in the body and attached to artificial hygiene;
The rotation mechanism 5 is configured to rotate the main body case 7 by 90 ° compared to the time of imaging when the focal position is detected.

Next, FIG. 2 is a perspective view of a main part of the radiometer at the time of imaging for explaining the operation of the embodiment of FIG. 1, and FIG. 3 is a focus position for explaining the operation of the embodiment of FIG. It is a principal part perspective view of the radiometer at the time of detection. The operation of the embodiment shown in FIG. 1 will be described below with reference to FIGS. 2 and 3.

At the time of imaging the object 10, as shown in FIG. 2, the imaging direction of the line sensor 2 is set in a direction orthogonal to the moving direction 8 of the artificial satellite. A glass plate 6 is inserted in the middle of the optical path between the optical system 1 and the line sensor 2. When the focus position is detected, the entire body case 7 is
As shown in the drawing, the line sensor 2 is rotated by 90 °, and the imaging direction of the line sensor 2 is set parallel to the moving direction 8 of the artificial satellite. or,
At the same time, the glass plate 6 is replaced with the glass plate 3 by the moving mechanism 4.

Now, in the state shown in FIG. 3, the edge of the object 10 is imaged. At this time, assuming that the imaging cycle is the same as that at the time of the imaging shown in FIG. 2, the relationship between the speed of the artificial satellite in the moving direction 8 and the imaging cycle is one of the line sensors 2 on the target 10 in one imaging cycle.
The movement corresponds to the imaging trajectory 9 corresponding to the pixel.

Therefore, if the imaging is continued in the state of FIG. 3, the edge image of the object 10 is obtained in each line data in a state shifted by one pixel per line. Edge image of each line image is glass plate 3
By the effect of (1), the focus is adjusted from the out-of-focus state, and the state is shifted again.

FIGS. 4A and 4B are characteristic diagrams showing the correlation between the output level and the pixel number of the line sensor of the image data at the time of detecting the focal position in FIG.

FIG. 4 (a) shows a state where the focus is shifted, and FIG. 4 (b) shows a state where the focus is almost adjusted. The vertical axis indicates the output level 11 and the horizontal axis indicates the pixel number of the line sensor 2.

As described above, by obtaining the image data in various focusing positions by the effect of the glass plate 3, it is possible to determine which thickness of the glass plate 3 corresponds to the best focus position, and to determine the thickness and the glass plate 6. From the relationship of the thickness, it is possible to obtain data on how much the focus position should be adjusted at the time of imaging shown in FIG.

〔The invention's effect〕

As described above, the present invention makes the line sensor parallel to the traveling direction of the satellite and replaces the parallel flat glass in front of the line sensor with wedge-shaped glass, so that the image data from the line sensor can be used directly and in a short time. There is an effect that the best focus position can be detected. Further, since it can be confirmed by the data of the main body itself, the detection accuracy becomes very high, and therefore, there is an effect that the focus adjustment accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
FIG. 3 is a perspective view of a main part of the radiometer at the time of imaging for explaining the operation of the embodiment of FIG. 3, and FIG. 3 is a perspective view of a main part of the radiometer at the time of detecting the focus position for explaining the operation of the embodiment of FIG. FIGS. 4 (a) and 4 (b) are characteristic diagrams showing the correlation between the output level and the pixel number of the line sensor of the image data at the time of detecting the focal position in FIG. 3, respectively. DESCRIPTION OF SYMBOLS 1 ... Optical system, 2 ... Line sensor, 3 ... Wedge-shaped glass plate, 4 ... Moving mechanism, 5 ... Rotation mechanism, 6 ... Flat glass plate, 7 ... Body case, 8 ... …Direction of movement,
9: imaging locus corresponding to one pixel, 10: target, 11:
Output level, 12: Pixel number.

Claims (1)

(57) [Claims] 1. A radiometer comprising: a line sensor for imaging a continuously moving target; and an optical system for imaging light from the target on a light receiving surface of the line sensor, wherein the line sensor and the optical system are provided. A first transparent plate whose two opposing surfaces that can be inserted and removed in the middle of the optical path between the first sensor and the two parallel surfaces that can be inserted and removed in the middle of the optical path between the line sensor and the optical system have the line A second transparent plate inclined along the imaging direction of the sensor, a moving mechanism that inserts the first transparent plate into the optical path at the time of imaging and inserts the second transparent plate into the optical path at the time of focus position detection; A rotation mechanism that changes the imaging direction of the line sensor by 90 ° when the focal position is detected.