JPH08201458A - Microwave radiometer - Google Patents

Abstract

PURPOSE: To reduce the weight of a flying object while enhancing the distance resolution by turning two antennas and turning parts in the opposite directions so that the area between the regions being observed by one antenna is observed by the other antenna. CONSTITUTION: Turning parts 4a, 4b are begun to turn in the opposite directions and the area 12a, between the regions being observed by one antenna 1a provided for one microwave radiometer, is observed by an antenna 1b provided for the other microwave radiometer. Since the volume of data being acquired is increased as compared with the case where only one antenna is employed and the overlapped data is also increased, the distance resolution is enhanced. Furthermore, when the turning parts 4a, 4b are begun to turn in the opposite directions, no rotator is required because the turning part 4b has the function of rotator and the unnecessary weight can be removed from a flying object 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave radiometer mounted on a flying body such as an artificial satellite or an aircraft for observing the ground surface.

[0002]

2. Description of the Related Art A microwave radiometer receives noise power in the microwave band that is naturally radiated from the ground surface and the atmosphere,
By measuring the temperature, which is proportional to the received noise power,
It is a passive remote sensor that measures the physical properties of an observation target. It is mounted on a spacecraft such as an artificial satellite or an aircraft and scans the ground surface. An image is created from the data obtained as a result of this scanning and is used for resource observation and the like.

FIG. 6 is a block diagram of a conventional microwave radiometer. Reference numeral 1 denotes an antenna, which receives noise power in the microwave band radiated from an observation target such as the ground surface or the atmosphere. A receiving unit 2 amplifies, detects, and A / D converts noise power received by the antenna 1. A signal processing unit 3 edits the observation data converted by the receiving unit 2 into a predetermined format. A rotating unit 4 includes the antenna 1, the receiving unit 2, and the signal processing unit 3. Reference numeral 5 denotes a rotation drive unit that controls the rotation of the rotation unit 4. Reference numeral 6 denotes a rotating object that rotates in the opposite direction to the rotating unit 4. An interface unit 7 outputs the data of the signal processing unit 3 to the flying body 9. Reference numeral 8 is a power source, and 9 is a flying object equipped with a microwave radiometer. 10 includes 7 and 8 and is hereinafter referred to as a fixed part.

FIG. 7 is an external view of a conventional microwave radiometer. 1, 4, 5, 6, 9, and 10 are the same as those in FIG. Reference numeral 11 is a beam of the antenna 1, and 12 is a region where the antenna beam 11 illuminates the ground surface or the atmosphere. Reference numeral 13 is a rotating shaft of the rotating unit 4.

In the microwave radiometer, the antenna beam 1
In order to keep the angle θ incident on the ground surface observed by 1 always constant, the antenna 1 is tilted at a constant angle φ with respect to the rotation axis direction of the flying body, and then the rotating portion 4 including the antenna 1 is fixed. It scans the ground surface while rotating at a speed. Here, the rotation axis is a straight line connecting the microwave radiometer and the center of the earth. The ground surface is observed at an angle α centered on the flight direction of the spacecraft. However, due to this rotation, the moment, the center of gravity of the rotating portion, and the number of rotations vary, and unnecessary torque is generated as a disturbance.
Then, the attitude of the flying body 9 is disturbed. In order to cancel this disturbance of posture, the microwave radiometer
At present, a rotating body 6 that has the same angular momentum as the rotating unit 4 and rotates in the opposite direction is required. This rotating object 6
Is required for each rotating unit 4.

[0006]

In the conventional microwave radiometer, one antenna is provided for each microwave radiometer.
Only one is provided. Therefore, there is only one rotating object for the microwave radiometer, and the microwave radiometer is swayed and disturbed in posture at startup. In order to eliminate this, the conventional microwave radiometer contains a rotating object that is not necessary for observation. That is, the unnecessary weight was included. The flying body should be light, and unnecessary weight should be reduced from the flying body. Further, in order to obtain a clearer image, it is necessary to prevent the microwave radiometer itself from shaking and improve the range resolution. The antenna beam has a divergence, and there is a limit to how narrow the width can be. This is because the size of the antenna becomes large in order to squeeze and it becomes difficult to mount the antenna on a flying object. Therefore, in order to improve the distance resolution, it was necessary to collect more data in the vicinity of a certain observation point in detail and improve the overlap ratio of the area where the antenna beam illuminates the ground surface. However, since the number of antennas is one at present, the satellite traveling speed is slowed down in order to improve the overlap rate.

[0007]

In the first embodiment of the present invention, an antenna forming an antenna beam for receiving noise power in the microwave band radiated from the surface of the earth or the atmosphere, and an antenna beam input from the antenna. A receiving unit that amplifies, detects, and A / D converts the noise power in the microwave band and outputs the observation data to the signal processing unit, and the observation data from the reception unit is edited into a predetermined format and output to the interface unit. The signal processing unit, the interface unit that outputs the observation data input from this signal processing unit to the aircraft equipped with the microwave radiometer, and the microwave from the aircraft equipped with the microwave radiometer In order to make the angle of incidence of the antenna beam incident on the surface of the earth observed by the power supply unit that supplies power to each of the above units constituting the radiometer constant, Inclination of a certain angle with respect to a straight line connecting the microwave radiometer and the center of the earth, the rotation part that rotates the antenna, the receiving part and the signal processing part together with this straight line as a rotation axis, and the rotation of the rotation part. In a microwave radiometer equipped with a rotation drive unit for performing control so as to be performed at a constant speed, two rotary antennas, a reception unit and a signal processing unit are mounted in the rotation axis direction of the microwave radiometer, and one of them is mounted. Rotate the rotating part in the opposite direction to the other rotating part,
Between the areas observed by the antenna provided on one side of the microwave radiometer, the antenna provided on the other side is used for observation.

Further, in the second embodiment of the present invention, two antennas, a receiving section, a signal processing section, and a rotating section are mounted in a direction perpendicular to the rotation axis of the microwave radiometer, and one rotating section rotates the other. It is rotated in the opposite direction to the section, and one half of the observation area is observed with the antenna provided on one side of the microwave radiometer, and the other half is observed with the antenna provided on the other side.

[0009]

In the first embodiment of the present invention, the disturbance of the attitude of the flying object caused by the rotation of the rotating part is mounted on one microwave radiometer in which two rotating parts are mounted in the rotating shaft direction, and one rotating part is mounted. By rotating the other rotating part in the opposite direction, the two rotating parts erase each other and the rotating object becomes unnecessary,
Reduce unnecessary weight of the flying vehicle. Further, by mounting two rotating parts on one microwave radiometer, the number of acquired observation data can be increased and the range resolution can be improved as compared with the case of observing with one antenna.

In the second embodiment of the present invention, the disturbance of the attitude of the flying object caused by the rotation of the rotating portion
Two rotating parts are mounted on one microwave radiometer in a direction perpendicular to the rotation axis, and one rotating part is rotated in the opposite direction to the other rotating part so that the two rotating parts erase each other, and the rotating object Reduces the unnecessary weight of the flying object.
In addition, one microwave radiometer equipped with two rotating parts,
By observing one half of the observation area with the antenna provided on one side of the microwave radiometer and observing the other half on the other side with the antenna provided on the other side, the observation width is wider than when observing with one antenna. Since the traveling speed of the satellite can be reduced during the observation period, the area where the data overlaps with the traveling direction is increased and the range resolution can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating the present invention. In the figure, 7-10 shows the same thing as FIG. Also, 1a, 1
b is an antenna provided in the axial direction of the rotating shaft 13, 2a,
2b is a receiving unit, 3a and 3b are signal processing units, 4a and 4b are rotating units, and 5a and 5b are rotation driving units.
It corresponds to 1, 2, 3, 4, and 5.

Embodiment 1. FIG. 2 is an external view of a microwave radiometer for explaining the first embodiment of the present invention. In the figure, 1
Reference characters a, 1b, 4a, 4b, 5a, 5b, 9, and 10 denote the same as those in FIG. Moreover, 13 is the same as FIG. By starting the rotations of the rotating unit 4a and the rotating unit 4b in reverse, the rotating unit 4b has the function of the rotating unit 6 in FIG. 6, so that the rotating unit 6 is unnecessary.

FIG. 3 is an external view for explaining the first embodiment of the present invention. In the figure, 1a, 1b, 4a, 4b, 5
Reference numerals a, 5b, 9 and 10 are the same as those in FIG. Also, 1
1a and 11b are 11 and 12a and 12b of FIG. 7 are 1 of FIG.
Same as 2. Here, the rotations of the rotating unit 4a and the rotating unit 4b are started in reverse. Further, by observing between the regions 12a observed by the antenna 1a provided on one side of the microwave radiometer with the antenna 1b provided on the other side, the number of acquired data is increased as compared with the case of observing by one antenna, and Since the overlapping portion increases, the distance resolution improves.

Example 2. FIG. 4 is an external view of a microwave radiometer for explaining the second embodiment of the present invention. In the figure, 1
Reference characters a, 1b, 4a, 4b, 5a, 5b, 9, and 10 denote the same as those in FIG. Moreover, 13a and 13b are the same as 13 of FIG. By starting the rotations of the rotating unit 4a and the rotating unit 4b in reverse, the rotating unit 4b has the function of the rotating unit 6 in FIG. 6, so that the rotating unit 6 is unnecessary. The antennas 1a, 1
b, the rotating portions 4a and 4b, the rotation driving portions 5a and 5b, and the fixed portion 10 are arranged in a direction perpendicular to the rotating shaft 13.

FIG. 5 is an external view of observation for explaining the second embodiment of the present invention. In the figure, 1a, 1b, 4a, 4b, 5
Reference numerals a, 5b, 9 and 10 are the same as those in FIG. Also, 1
1a and 11b are 11 and 12a and 12b of FIG. 7 are 1 of FIG.
Same as 2. Here, the rotations of the rotating unit 4a and the rotating unit 4b are started in reverse. Also, with the antenna 1a provided on one side of the microwave radiometer, one half on the one side equipped with the microwave radiometer is observed from the traveling direction of the flying object to the angle α, and with the antenna 1b provided on the other side Observe one half from the direction of travel up to angle α. As a result, the observation angle becomes 2 ^* α, and when the observation is performed with one antenna, that is, the observation width increases from the observation angle α. Therefore, in the conventional observation cycle, the traveling speed of the satellite can be reduced, so that the area where the data overlaps increases and the range resolution improves.

[0016]

According to the first embodiment of the present invention, in the microwave radiometer, two rotary parts and antennas are mounted in the rotary axis direction of the microwave radiometer, and one rotary part is opposite to the other rotary part. Since it is rotated in the same direction, the disturbance of the posture of the flying object caused by the rotation of the rotating part can be erased by the two rotating parts without using extra weight, and the unnecessary weight of the flying object can be reduced. There is an effect. In addition, since the area between the areas to be observed by the antenna provided on one side of the microwave radiometer is observed by the antenna provided on the other side, the number of acquired data per unit time will be increased compared to the case of observation with one antenna. There is an effect that the resolution can be improved.

In the second embodiment of the present invention, two rotating parts and antennas are mounted in a direction perpendicular to the rotation axis of the microwave radiometer, and one rotating part is rotated in the opposite direction to the other rotating part. Since there is no extra weight, it can be erased by the two rotating parts without using an extra weight, and the unnecessary weight of the flying object can be reduced. In addition, since the antenna provided on one side of the microwave radiometer observes one half of the observation area and the antenna provided on the other side observes the other half, the observation width is wider than when using one antenna. Since the traveling speed of the satellite can be reduced in the observation period of 3, there is an effect that the overlap of data in the traveling direction can be increased and the range resolution can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of the present invention.

FIG. 2 is an external view of a radiometer for explaining the first embodiment of the present invention.

FIG. 3 is an external view of observation for explaining the first embodiment of the present invention.

FIG. 4 is an external view of a radiometer for explaining a second embodiment of the present invention.

FIG. 5 is an external view of observation for explaining the second embodiment of the present invention.

FIG. 6 is a configuration diagram of a conventional microwave radiometer.

FIG. 7 is an external view of a conventional microwave radiometer.

[Explanation of symbols]

1 antenna, 2 receiving part, 3 signal processing part, 4 rotating part, 5 rotating drive part, 6 rotating object, 7 interface part, 8 power supply, 9 flying object, 10 fixed part, 11
Antenna beam, 12 Antenna beam illuminated area,
13 rotation axis, 1a antenna, 1b antenna, 2a
Receiver, 2b Receiver, 3a Signal processor, 3b Signal processor, 4a Rotator, 4b Rotator, 5a Rotation driver, 5b Rotation driver, 11a Antenna beam, 1
1b antenna beam, 12a antenna beam illuminated area, 12b antenna beam illuminated area, 13a rotation axis, 13b rotation axis.

Claims (2)

[Claims] 1. An antenna that forms an antenna beam for receiving noise power in the microwave band radiated from the ground surface or the atmosphere, and a signal received by the antenna is amplified / detected / detected.
A receiving unit for A / D converting and outputting observation data, a signal processing unit for editing the observation data from the receiving unit into a predetermined format, and a constant incident angle of the antenna beam on the ground surface observed. For this purpose, the antenna is attached at a certain angle with respect to a straight line connecting the microwave radiometer and the center of the earth, and at least a rotating portion for rotating the antenna with the straight line as a rotation axis and the rotating portion is rotated at a constant speed. In a microwave radiometer mounted on a flying object, the rotation driving section is controlled so that the antenna and two rotation sections are provided in the rotation direction, and the rotation directions of the antenna are opposite to each other. So that the area between the regions observed by the one antenna is observed by the other antenna. Systeme. 2. An antenna that forms an antenna beam for receiving noise power in the microwave band radiated from the ground surface or the atmosphere, and a signal received by the antenna is amplified / detected / detected.
A receiving unit for A / D converting and outputting observation data, a signal processing unit for editing the observation data from the receiving unit into a predetermined format, and a constant incident angle of the antenna beam on the ground surface observed. For this purpose, the antenna is attached at a certain angle with respect to a straight line connecting the microwave radiometer and the center of the earth, and at least a rotating portion for rotating the antenna with the straight line as a rotation axis and the rotating portion is rotated at a constant speed. In a microwave radiometer mounted on a flying body, the rotation driving unit for controlling so that the antenna and the rotation unit are provided in the direction perpendicular to the rotation axis, and the rotation direction of the antenna is changed. Set the antennas so that they are in opposite directions, and one half of the observation area is observed with one antenna and the other half is observed with the other antenna. Microwave radiometer, characterized in that the.