JPH10160774A - Microwave radiometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a microwave radiometer in which low temperature and high temperature calibration can be carried out without requiring a reflector for low temperature calibration and a high temperature calibration source. SOLUTION: The microwave radiometer comprises a reflector 12a for reflecting a microwave noise radio wave radiated from the surface of the earth, a drive mechanism 13a for switching the beam direction of the reflector 12a between the direction of the earth and the deep space direction for observing the background radiation of the space, a primary radiator 5 for receiving a radio wave reflected on the reflector 12a, a reflector 12b interposed between the reflector 12a and the primary radiator 5 in order to block input of radio wave to the primary radiator 5, and a mechanism 13b for driving the reflector 12b to pass a radio wave to the primary radiator 5 or block the radio wave.

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 satellite for observing the earth's surface.

[0002]

2. Description of the Related Art FIG. 13 is a view showing a conventional microwave radiometer mounted on an artificial satellite for observing the earth's surface. In FIG.
Is a low-temperature calibration reflector, 4 is a high-temperature calibration source, 5 is a primary radiator,
6 is a low noise receiver, 7 is a signal processing unit, 8 is a rotation mechanism, 9
Is a rotating part, 10 is the earth, and 11 is a deep space that radiates 2.7K cosmic background radiation which is a calibration signal at the time of low-temperature calibration. FIG. 14 is a diagram showing a signal flow at the time of observation. FIG. 15 is a diagram showing a signal flow at the time of low-temperature calibration. FIG.
FIG. 6 is a diagram showing a signal flow at the time of high-temperature calibration. FIG.
It is a figure which shows the example of a timing of observation, low-temperature calibration, and high-temperature calibration.

Next, the operation will be described with reference to FIGS. In order to scan an observation target on the earth surface 10, the microwave radiometer is configured to include an observation reflector 2, a primary radiator 5, a low noise receiver 6, a rotating unit 9 including a signal processing unit 7, and an observation reflector 2. It is rotated by a rotation mechanism 8. Since the gain of the low-noise receiver 6 fluctuates due to the external thermal environment, the low-temperature calibration source and the high-temperature calibration source are observed at regular intervals,
It is necessary to calibrate the input and output of the microwave radiometer. Here, conventionally, a low-temperature calibration reflecting mirror 3 is arranged to use the space background radiation from the deep space 11 of 2.7 K as a low-temperature calibration source, and a radio wave absorber temperature-controlled by a heater as a high-temperature calibration source 4. Was used. Figure 14 shows the signal flow during observation.
This will be described with reference to FIG. At the time of observation, a radio wave radiated from the earth surface 11 is received by the primary radiator 5 via the observation reflector 2. The received signal received by the primary radiator 5 is amplified, detected and integrated by the low noise receiver 6, A / D converted and formatted by the signal processing unit 7, and then transmitted by a transmitter (not shown). It is transmitted to the ground as an observation signal. The signal flow during the low-temperature calibration will be described with reference to FIG. At the time of low-temperature calibration, cosmic background radiation of 2.7 K from deep space is received by the primary radiator 5 via the low-temperature calibration reflector 3. The flow of the signal after reception is the same as at the time of observation. The signal flow during the high-temperature calibration will be described with reference to FIG. At the time of high-temperature calibration, the radiated radio wave from the high-temperature calibration source 4 is received by the primary radiator 5. The flow of the signal after reception is the same as at the time of observation. FIG. 17 shows an example of low-temperature calibration, high-temperature calibration, and observation timing. Low temperature calibration reflector 3
And the high-temperature calibration source 4 is mechanically installed on the scanning arc of the primary radiator 5, and when the primary radiator 5 passes directly below the low-temperature calibration reflecting mirror 3 once per scanning cycle, When a calibration signal is obtained and passes immediately below the high-temperature calibration source 4, a high-temperature calibration signal is obtained.

[0004]

When a conventional microwave radiometer is mounted on a satellite and the reception output is calibrated, a low-temperature calibration reflector 3 and a high-temperature calibration source 4 for inputting cosmic background radiation are used. Separately, and it was necessary to observe them during a constant rotation cycle. For this reason, the observation width in which the earth surface can be observed due to blocking by the low-temperature calibration reflecting mirror 3 and the high-temperature calibration source 4 has been limited. In addition, the low-temperature calibration reflector 3
In addition, it is necessary to rotate all devices except the high-temperature calibration source 4 by the rotation mechanism 8 and control the primary radiator to a position where radio waves from the low-temperature calibration reflector 3 and the high-temperature calibration source 4 can be received.

Further, in order to secure the field of view of the low-temperature calibration reflecting mirror 3, the arrangement of equipment and the position of the satellite are limited. In addition, since the satellite structure, struts for holding the main reflector, and the like enter the field of view of the low-temperature calibration reflecting mirror 3 and a clear view cannot be secured, the low-temperature calibration signal is changed from 2.7K, which is the space background radiation. There was a problem of deviation.
Further, there is a problem that an error occurs in the low-temperature calibration signal due to the uncertainty of the fluctuation amount of the noise temperature of the satellite structure, the strut, and the like in orbit.

Further, in order to control the radio wave absorber, which is the high-temperature calibration source 4, to a constant temperature, it is necessary to mount a heater inside the radio wave absorber to perform temperature control with high accuracy. Further, there is a problem that extra heater power is consumed for heater control. Further, there is a problem that an error occurs in the high-temperature calibration signal due to the temperature distribution of the radio wave absorber.

[0007] Regarding the timing of performing calibration and the number of calibration data, regardless of the necessity, the calibration reflector 3 and the high-temperature calibration source 4 are restricted to a positional relationship that can be observed by the primary radiator. There is a problem that calibration can be performed only once in one rotation cycle by the mechanism 8, and calibration cannot be performed at an optimum calibration timing.

The present invention has been made to solve the above problems, and provides a microwave radiometer which enables calibration without using a low-temperature calibration mirror and a high-temperature calibration source. .

[0009]

SUMMARY OF THE INVENTION A microwave radiometer according to a first aspect of the present invention uses a high-temperature calibration source so that cosmic background radiation from cosmic background radiation can be input without using a low-temperature calibration reflector. A first reflector, a first drive mechanism for driving the first reflector, a primary radiator, and a first reflector and a primary radiator so that a high-temperature calibration input can be performed without using the first reflector. A second reflecting mirror in between, and a second reflecting mirror for driving the second reflecting mirror.
, A low-noise receiver, and a signal processing unit.

Further, the microwave radiometer according to the second aspect of the present invention provides a reflector, a reflector driving mechanism, and a high-temperature mirror so that cosmic background radiation from cosmic background radiation can be input without using a low-temperature calibration reflector. It comprises a calibration source, a rotation mechanism, a primary radiator, a low-noise receiver, and a signal processing unit.

Further, the microwave radiometer according to the third aspect of the present invention includes a first reflecting mirror and a first reflecting mirror for driving the first reflecting mirror so that a high-temperature calibration input can be performed without using a high-temperature calibration element. , A primary radiator, a second reflector between the first reflector and the primary radiator, a second drive mechanism for driving the second reflector, and low-noise reception. And a signal processing unit.

A microwave radiometer according to a fourth aspect of the present invention is capable of inputting a cosmic background radiation from a cosmic background radiation without using a low-temperature calibration reflector, and a high-temperature calibration without using a high-temperature calibration source. In order to enable input, the first single-polarized transmission mirror and the polarization plane of the first mirror are changed to 90.
A first drive mechanism for rotating the first degree, a primary radiator,
A second half-polarized transmission mirror between the first reflector and the primary radiator, a second drive mechanism for rotating the second polarization plane by 90 degrees to change the plane of polarization, and a polarization splitter , A low-noise receiver, and a signal processing unit.

The microwave radiometer according to the fifth aspect of the present invention can input cosmic background radiation from cosmic background radiation without using a low-temperature calibration reflector, and can perform high-temperature calibration without using a high-temperature calibration source. In order to enable input, the first single-polarized transmission mirror and the polarization plane of the first mirror are changed to 90.
A first drive mechanism for rotating the first degree, a primary radiator,
A second half-polarized transmission mirror between the first reflector and the primary radiator, a second drive mechanism for rotating the second polarization plane by 90 degrees to change the plane of polarization, and a polarization splitter , An RF switch, a low-noise receiver, and a signal processing unit.

Further, the microwave radiometer according to the sixth aspect of the present invention can input the cosmic background radiation from the cosmic background radiation without using the low-temperature calibration reflector, and can perform the high-temperature calibration without using the high-temperature calibration source. In order to enable input, the first single-polarized transmission mirror and the polarization plane of the first mirror are changed to 90.
A first drive mechanism for rotating the first degree, a primary radiator,
A second half-polarized transmission mirror between the first reflector and the primary radiator, a second drive mechanism for rotating the second polarization plane by 90 degrees to change the plane of polarization, and a polarization splitter , A low-noise receiver corresponding to each polarization, and a signal processing unit.

A microwave radiometer according to a seventh aspect of the present invention is capable of inputting cosmic background radiation from cosmic background radiation without using a low-temperature calibration reflector, and is also capable of performing high-temperature calibration without using a high-temperature calibration source. A first mesh-type reflecting mirror, a first driving mechanism for changing the mesh roughness of the mesh of the first mesh-type reflecting mirror, a primary radiator, and a first mesh-type mirror so as to allow input. A second mesh reflector between the reflector and the primary radiator, a second drive mechanism for changing the coarseness of the mesh of the second mesh reflector, a low noise receiver, It has a signal processing unit.

A microwave radiometer according to an eighth aspect of the present invention is capable of inputting cosmic background radiation from cosmic background radiation without using a low-temperature calibration reflector, and is also capable of performing high-temperature calibration without using a high-temperature calibration source. A first mesh-type reflecting mirror, a first driving mechanism for changing the mesh roughness of the mesh of the first mesh-type reflecting mirror, a primary radiator, and a first mesh-type mirror so as to allow input. A second mesh-type reflector between the reflector and the primary radiator, a second drive mechanism for changing the coarseness of the mesh of the second mesh-type mirror, a group splitter, It has a low-noise receiver and a signal processing unit.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to Embodiment 1 of the present invention.
Is a microwave radiometer, 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 10 is the earth, 11 is deep space, 12 is
Reference numerals a and 12b denote reflecting mirrors, and reference numerals 13a and 13b denote reflecting mirror driving mechanisms. FIG. 2 is a diagram showing a signal flow at the time of observation by the microwave radiometer of the present invention. FIG. 3 is a diagram showing a signal flow at the time of low-temperature calibration of the microwave radiometer of the present invention. FIG. 4 is a diagram showing a signal flow at the time of high-temperature calibration of the microwave radiometer of the present invention.

Next, the operation will be described with reference to FIGS. First, the flow of signals during observation will be described with reference to FIG. At the time of observation, the reflecting mirror 1 is driven by the reflecting mirror driving mechanism 13a.
The direction of the mirror surface 2a is controlled so that the microwave noise radio wave radiated from the earth surface 10 is reflected by the reflecting mirror 13a and can be received by the primary radiator 5. The reflecting mirror 12b is set in parallel with the beam direction of the primary radiator 5 by the reflecting mirror driving mechanism 13b. In that case, the earth surface 1
Microwave noise radio wave radiated from 0
And is received by the primary radiator 5. The received radio wave is amplified, detected and integrated by the low-noise receiver 6, A / D converted and formatted by the signal processing unit 7, and then sent to the ground as an observation signal by a transmitter (not shown). Transmitted.

The flow of signals during low-temperature calibration will be described with reference to FIG. At the time of low-temperature calibration, the mirror surface of the reflecting mirror 12a is made parallel to the beam direction of the primary radiator by using the reflecting mirror driving mechanism 13a. Further, the reflecting mirror 12b is slid in a direction parallel or lateral to the beam direction of the primary radiator using the reflector driving mechanism 13b to release the input of the primary radiator. Reflector 12
By making the mirror surface of a and the mirror surface of the reflecting mirror 12b parallel to the beam direction of the primary radiator 5, the beam of the primary radiator 5 is directed to the zenith direction opposite to the earth 10, and The cosmic background radiation is received directly by the primary radiator 5. Since the low-temperature calibration signal, which is the cosmic background radiation, can be received from the zenith direction, the received signal received by the satellite structure is transmitted to the ground by the same processing as the observation.

The signal flow during high-temperature calibration will be described with reference to FIG. At the time of high-temperature calibration, the mirror surface of the reflector 12b is controlled by the reflector driving mechanism 13b in a direction perpendicular to the beam direction of the primary radiator. At this time, the direction of the reflecting mirror 12a is not particularly limited. The mirror surface of the reflecting mirror 12b is used
Thus, the beam is made perpendicular to the beam direction of the primary radiator, so that no external radio wave is input to the primary radiator 5. Therefore, the radio wave received by the primary radiator 5 is only the thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. By controlling the physical temperature of the primary radiator 5 to 300 K using a heater, a radio wave corresponding to 300 K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation. As described above, the timing at which the low-temperature and high-temperature calibrations are performed depends on the mirror driving mechanisms 13a and 13
The drive timing is determined by the drive timing of b, but the drive timing can be set arbitrarily.

Embodiment 2 FIG. FIG. 5 is a diagram showing Embodiment 2 of the present invention. In the figure, 1 is a microwave radiometer, 4 is a high-temperature calibration source, 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 8 is a rotation mechanism, 9 is a rotation unit, 10
Is the earth, 11 is a deep space, 12 is a reflecting mirror, and 13 is a reflecting mirror driving mechanism.

Next, the operation will be described with reference to FIG. In order to receive the observation signal, the low-temperature calibration signal, and the high-temperature calibration signal, the rotating unit 9 and the reflecting mirror 12 are rotated by the rotating mechanism 8. The high-temperature calibration source 4 does not rotate. The rotating unit 9 includes a primary radiator 5, a low-noise receiver 6, and a signal processing unit 7. The primary radiator 5 is rotated by a rotating mechanism 8, and is switched to a position where radio waves from the high-temperature calibration source 4 are not input to the primary radiator 5. .
At the time of observation, the mirror surface direction of the reflector 12 is controlled by the reflector driving mechanism 13, and the microwave noise radio wave radiated from the earth surface 10 is reflected by the reflector 12 and is reflected by the primary radiator 5.
Set in the direction that can be received with. At this time, the primary radiator 5 is set at a position where the radio wave from the high-temperature calibration source 4 is not input by the rotating mechanism 8. In that case, the microwave noise radio wave radiated from the earth surface 11 is reflected by the reflector 12 and received by the primary radiator 5. The received radio wave is amplified, detected and integrated by the low-noise receiver 6, A / D converted and formatted by the signal processing unit 7, and then sent to the ground as an observation signal by a transmitter (not shown). Transmitted. During low-temperature calibration, the mirror drive mechanism 1
3 is used to make the mirror surface of the reflecting mirror 12 parallel to the beam direction of the primary radiator. At this time, the primary radiator 5 is set at a position where the radio wave from the high-temperature calibration source 4 is not input by the rotating mechanism 8. By making the mirror surface of the reflecting mirror 12 parallel to the beam direction of the primary radiator 5, the beam of the primary radiator 5
It will face the zenith direction opposite to 0, and the deep space 11
The cosmic background radiation from is directly received by the primary radiator 5.
The received signal is transmitted to the ground by the same processing as the observation. At the time of high-temperature calibration, a radio wave from the high-temperature calibration source 4 is input to the primary radiator 5. At this time, the primary radiator 5
Is set so that the rotating mechanism 8 is located at a position where radio waves from the high-temperature calibration source 4 are input. The direction of the reflecting mirror 12 is not particularly limited. The received signal received by the primary radiator 5 is transmitted to the ground by the same processing as at the time of observation.

Embodiment 3 FIG. FIG. 6 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a high-temperature calibration source according to Embodiment 3 of the present invention, wherein 1 is a microwave radiometer, and 5 is a primary radiator. , 6 is a low noise receiver,
7 is a signal processing unit, 10 is the earth, 11 is deep space, 12a,
12b is a reflecting mirror, and 13a and 13b are reflecting mirror driving mechanisms.

Next, the operation will be described with reference to FIG. At the time of observation, the reflecting mirror 12b is connected to the reflecting mirror driving mechanism 13b.
Is set in parallel with the beam direction of the primary radiator 5.
That is, the reflecting mirror 12b is set at the position 12b '.
The reflecting mirror 12a reflects the microwave noise radio wave radiated from the earth surface 10 on the primary radiator 5
The direction is fixed so that it can be received. In that case, the microwave noise radio wave radiated from the earth surface 10
It is received by the primary radiator 5 via 2a. The received radio wave is amplified, detected and integrated by the low noise receiver 6, and then
After A / D conversion and formatting are performed by the signal processing unit 7, the signals are transmitted to the ground as observation signals by a transmitter (not shown). At the time of low-temperature calibration, the mirror surface of the reflecting mirror 12a is set to a position where radio waves from the deep space direction are input using the reflecting mirror driving mechanism 13a. That is,
The reflector 12b is set at the position 12b ". In this case, the cosmic background radiation from the deep space 11 is received by the primary radiator 5 via the reflector 12b. The received signal is the same as that at the time of observation. During high-temperature calibration, the mirror surface of the reflecting mirror 12b is moved to the reflecting mirror driving mechanism 13b.
Control in a direction perpendicular to the beam direction of the primary radiator 5. That is, the reflecting mirror 12b is set at the position of 12b. At this time, the mirror surface of the reflecting mirror 12b is moved to the reflecting mirror driving mechanism 1
By making the beam direction of the primary radiator perpendicular to the primary radiator 3b, the primary radiator 5 does not receive an external radio wave. Therefore, the radio wave received by the primary radiator 5 is only the thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. By controlling the physical temperature of the primary radiator 5 to 300 K using a heater, a radio wave corresponding to 300 K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation.

Embodiment 4 FIG. 7 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to a fourth embodiment of the present invention. 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 10 is the earth,
11 is a deep space, 14a and 14b are single polarization transmission type mirrors,
Reference numerals 15a and 15b denote single-polarized reflection mirror driving mechanisms, and reference numeral 16 denotes a polarization splitter. FIG. 8 is a diagram showing the polarization planes of the primary radiator and the first and second single-polarization transmission mirrors during observation, low-temperature calibration, and high-temperature calibration.

Next, the operation will be described with reference to FIGS. At the time of observation, as shown in FIG. 8 (c), the single polarization transmission mirror 14a is driven by the single polarization reflection mirror driving mechanism 15a.
Is rotated so as to form 90 degrees with the polarization direction desired to be received through the primary radiator 5, and the microwave noise radio wave radiated from the earth surface 10 is reflected by the single polarization transmission type reflection mirror 13a. It is received by the primary radiator 5. Also,
At this time, the single polarization transmission mirror 14b is rotated by the single polarization reflection mirror driving mechanism 15b so that the polarization direction received by the primary radiator 5 is transmitted. In this case, the microwave noise radio wave radiated from the earth surface 10 is reflected only by the polarized wave received through the primary radiator 5 by the single polarization transmission type reflector 14 a and received by the primary radiator 5. The received signal goes to the low noise receiver 6 after the polarization splitter 16 separates the polarization desired to be received by the primary radiator. After being amplified, detected and integrated by the low-noise receiver 6, the signal processing unit 7 performs A / D conversion and formatting, and then transmits to the ground as an observation signal by a transmitter (not shown).

At the time of low-temperature calibration, the single-polarization reflecting mirror driving mechanism 1
8A, the transmission polarization direction of the single polarization transmission type reflection mirror 14a is rotated in the same direction as the polarization direction desired to be received through the primary radiator as shown in FIG. Transmit 2.7K. At this time, the single polarization transmission mirror 14b is rotated by the single polarization reflection mirror driving mechanism 15b so that the polarization direction received by the primary radiator 5 is transmitted. In this case, the transmission polarization direction of the single-polarization transmission type reflector 14a, the transmission polarization direction of the single-polarization transmission type reflector 14b, and the reception polarization direction of the primary radiator 5 become equal to each other. Cosmic background radiation is directly the primary radiator 5
Received at. The received signal is transmitted to the ground by the same processing as the observation.

At the time of high-temperature calibration, the single-polarization transmission type reflection mirror 14 is used.
As shown in FIG. 8A, the transmission polarization direction b is rotated by the single-polarization reflection mirror driving mechanism 15b in a direction perpendicular to the polarization direction received by the primary radiator 5. At this time, the transmission polarization direction of the single polarization transmission type reflection mirror 14a is not particularly limited. By making the transmission polarization direction of the single-polarization transmission type reflector 14b perpendicular to the polarization direction received by the primary radiator by the single-polarization reflector driving mechanism 15b, the primary radiator 5 receives radio waves from outside. There is no input. Therefore, the radio wave received by the primary radiator 5 is only the thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. By controlling the physical temperature of the primary radiator 5 to 300 K using a heater, 3
A radio wave corresponding to 00K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation. As described above, the timing at which the low-temperature and high-temperature calibrations are performed is determined by the timing at which the single-polarization reflecting mirror driving mechanisms 15a and 15b are driven, but the driving timing can be arbitrarily set.

Embodiment 5 FIG. 9 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to a fifth embodiment of the present invention. 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 10 is the earth,
11 is a deep space, 14a and 14b are single polarization transmission type mirrors,
Reference numerals 15a and 15b denote single-polarized reflection mirror driving mechanisms, 16 denotes a polarization splitter, and 17 denotes an RF switch.

Next, the operation will be described with reference to FIGS. At the time of observation, as shown in FIG. 8C, the transmission polarization direction of the single polarization transmission type mirror 14a is made 90 degrees with the polarization direction desired to be received through the primary radiator 5 by the single polarization reflection mirror driving mechanism 15a. And the microwave noise radio wave radiated from the earth surface 10
The light is reflected by 3 a and received by the primary radiator 5. At this time, the single polarization transmission mirror 14b is rotated by the single polarization reflection mirror driving mechanism 15b so that the polarization direction received by the primary radiator 5 is transmitted. In this case, the microwave noise radio wave radiated from the earth surface 10 is reflected only by the polarized wave received through the primary radiator 5 by the single polarization transmission type reflector 14 a and received by the primary radiator 5. The received signal is transmitted to the RF switch 17 after the polarization splitter 16 separates the polarization of the received signal received by the primary radiator 5. The RF switch 17 selects the polarization direction of the radio wave to be received, and only the reception signal of the selected polarization component goes to the low noise receiver 6. After being amplified, detected and integrated by the low-noise receiver 6, the signal processing unit 7 performs A / D conversion and formatting, and then transmits to the ground as an observation signal by a transmitter (not shown).

At the time of low-temperature calibration, as shown in FIG. 8 (b), the transmission polarization direction of the single-polarization transmission type reflector 14a is received through the primary radiator using the single-polarization reflection mirror driving mechanism 15a. In the same direction as above, and 2.7 K of cosmic background radiation from the deep space 11 is transmitted. At this time, the single-polarization transmission mirror 14b is connected to the single-polarization reflection mirror driving mechanism 15b.
, So that the polarization direction received by the primary radiator 5 is transmitted. In this case, the transmission polarization direction of the single-polarization transmission type reflector 14a, the transmission polarization direction of the single-polarization transmission type reflector 14b, and the reception polarization direction of the primary radiator 5 become equal to each other. Cosmic background radiation is directly received by the primary radiator 5. The received signal is transmitted to the ground by the same processing as the observation. At the time of high temperature calibration,
As shown in (a), the transmission polarization direction of the single-polarization transmission type reflector 14b is rotated by the single-polarization reflector drive mechanism 15b in a direction perpendicular to the polarization direction received by the primary radiator 5. At this time, the transmission polarization direction of the single polarization transmission type reflection mirror 14a is not particularly limited. By making the transmission polarization direction of the single-polarization transmission type reflector 14b perpendicular to the polarization direction received by the primary radiator 5 by the single-polarization reflector driving mechanism 15b, an external radio wave is transmitted to the primary radiator 5. Input disappears. Therefore, the radio wave received by the primary radiator 5 is only the thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, the primary radiator 5
The radio wave corresponding to the physical temperature is input to the primary radiator 5. The physical temperature of the primary radiator 5 is set to 300K using a heater.
, A radio wave corresponding to 300K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation.

Embodiment 6 FIG. FIG. 10 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to Embodiment 6 of the present invention, in which 1 is a microwave radiometer. 5 is a primary radiator, 6a and 6b are low noise receivers, 7 is a signal processing unit, 10
Is the earth, 11 is the deep space, 14a and 14b are single polarization transmission mirrors, 15a and 15b are single polarization reflection mirror driving mechanisms, 16
Is a polarization splitter.

Next, the operation will be described with reference to FIG. At the time of observation, the transmission polarization direction of the single polarization transmission mirror 14a is changed by the single polarization reflector driving mechanism 15a to the primary radiator 5.
The microwave noise radio wave radiated from the earth surface 10 is reflected by the single-polarization transmission type reflection mirror 13 a and received by the primary radiator 5. At this time, the single polarization transmission mirror 14b is rotated by the single polarization reflection mirror driving mechanism 15b so that the polarization direction received by the primary radiator 5 is transmitted. In this case, the microwave noise radio wave radiated from the earth surface 10 is reflected only by the polarized wave received through the primary radiator 5 by the single polarization transmission type reflector 14 a and received by the primary radiator 5. The received signal is separated from the received signal received by the primary radiator 5 by the polarization splitter 16, and then the low-noise receivers 6a and 6b provided for each polarization are separated.
Head for. In the low-noise receiver 6a, amplification, detection, and integration of a received signal having one polarization component separated by the polarization splitter 16 are performed. In the low-noise receiver 6b, amplification, detection, and integration of the received signal having the other polarization component are performed. The received signals detected by the low noise receivers 6a and 6b are subjected to A / D conversion and formatting by the signal processing unit 7, and then transmitted to the ground as observation signals by a transmitter (not shown).

At the time of low-temperature calibration, the single-polarization reflecting mirror driving mechanism 15 is used.
The transmission polarization direction of the single-polarization transmission mirror 14a is rotated in the same direction as the polarization direction desired to be received through the primary radiator using a, so that the space background radiation 2.7K from the deep space 11 is transmitted. At this time, the single polarization transmission mirror 14b is rotated by the single polarization reflection mirror driving mechanism 15b so that the polarization direction received by the primary radiator 5 is transmitted. in this case,
When the transmission polarization direction of the single polarization transmission type reflector 14a, the transmission polarization direction of the single polarization transmission type reflector 14b, and the reception polarization direction of the primary radiator 5 become equal, the space background from the deep space 11 is obtained. The radiation is received directly at the primary radiator 5. The received signal is transmitted to the ground by the same processing as the observation.

At the time of high-temperature calibration, the single-polarization transmission type reflection mirror 14 is used.
The transmission polarization direction b is rotated in a direction perpendicular to the polarization direction received by the primary radiator 5 by the single polarization reflector driving mechanism 15b. At this time, the transmission polarization direction of the single polarization transmission type reflection mirror 14a is not particularly limited. By making the transmission polarization direction of the single-polarization transmission type reflector 14b perpendicular to the polarization direction received by the primary radiator 5 by the single-polarization reflector driving mechanism 15b, an external radio wave is transmitted to the primary radiator 5. Input disappears. Therefore,
Radio waves received by the primary radiator 5 are only thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. The physical temperature of the primary radiator 5 is adjusted to 3 using a heater.
By controlling to 00K, a radio wave corresponding to 300K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation.

Embodiment 7 FIG. 11 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to a seventh embodiment of the present invention. 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 10 is the earth,
11 is a deep space, 18a and 18b are mesh reflectors, 1
9a and 19b are mesh driving mechanisms.

Next, the operation will be described with reference to FIG. At the time of observation, the mesh driving mechanism 19a adjusts the mesh roughness of the mesh of the mesh-type reflector 18a to the mesh roughness at which radio waves of the frequency desired to be received through the primary radiator 5 are reflected, and is radiated from the earth surface 10. The microwave noise radio wave is reflected by the mesh-type reflecting mirror 18 a and received by the primary radiator 5. At this time, the mesh-type reflecting mirror 18b is adjusted by the mesh driving mechanism 19b so that radio waves of the frequency received by the primary radiator 5 are transmitted. In this case, the microwave noise radio wave radiated from the earth surface 10 is reflected by the single polarization transmission type reflector 18 a through the primary radiator 5 and received by the primary radiator 5. The received signal goes to the low noise receiver 6. Low noise receiver 6
After being amplified, detected, and integrated by the A / D converter, A / D conversion and formatting are performed by the signal processor 7, and then transmitted to the ground as observation signals by a transmitter (not shown).

At the time of low-temperature calibration, the mesh driving mechanism 19a is used to adjust the mesh roughness of the mesh-type reflecting mirror 18a so that radio waves of the frequency desired to be received through the primary radiator 5 are transmitted. Space background radiation 2.7
K is transmitted. At this time, the mesh type mirror 1
8b adjusts the mesh roughness of the mesh so that the radio wave of the frequency received by the primary radiator 5 is transmitted by the mesh driving mechanism 19b. In this case, the cosmic background radiation from the deep space 11 passes through the mesh reflectors 18a and 18b and is received by the primary radiator 5. The received signal is transmitted to the ground by the same processing as the observation.

At the time of high-temperature calibration, the mesh type reflecting mirror 18b
Is adjusted by the mesh driving mechanism 19b so that radio waves of the frequency received by the primary radiator are reflected. At this time, the mesh roughness of the mesh-type reflecting mirror 18a is not particularly limited. By adjusting the coarseness of the mesh of the mesh-type reflecting mirror 18b and reflecting the radio wave of the frequency received by the primary radiator, the primary radiator 5 receives no external radio wave. Therefore, the primary radiator 5
Is only the thermal noise generated from the primary radiator 5. Since the thermal noise generated from the primary radiator 5 is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. By controlling the physical temperature of the primary radiator 5 to 300 K using a heater, a radio wave corresponding to 300 K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation.

Embodiment 8 FIG. FIG. 12 is a diagram showing a configuration of a microwave radiometer capable of performing calibration without using a low-temperature calibration reflector and a high-temperature calibration source according to Embodiment 8 of the present invention. 5 is a primary radiator, 6 is a low noise receiver, 7 is a signal processing unit, 10 is the earth,
11 is a deep space, 18a and 18b are mesh reflectors, 1
9a and 19b are mesh driving mechanisms, and 20 is a group branching filter.

Next, the operation will be described with reference to FIG. At the time of observation, the mesh driving mechanism 19a adjusts the mesh roughness of the mesh of the mesh-type reflector 18a to the mesh roughness at which radio waves of the frequency desired to be received through the primary radiator 5 are reflected, and is radiated from the earth surface 10. The microwave noise radio wave is reflected by the mesh-type reflecting mirror 18 a and received by the primary radiator 5. At this time, the mesh-type reflecting mirror 18b is adjusted by the mesh driving mechanism 19b so that radio waves of the frequency received by the primary radiator 5 are transmitted. In this case, the microwave noise radio wave radiated from the earth surface 10 is reflected by the single polarization transmission type reflector 18 a through the primary radiator 5 and received by the primary radiator 5. The received signal is subjected to frequency separation by the group splitter 20 for each frequency of the received signal. The received signal separated for each frequency by the group branching filter 20 is a low noise receiver 6a provided for each frequency.
And 6b. In the low-noise receiver 6a, amplification, detection, and integration of a received signal with respect to one frequency component frequency-separated by the group branching filter are performed. Also, the low noise receiver 6b
Then, amplification, detection, and integration of the received signal with respect to the other frequency component are performed. The received signals detected by the low noise receivers 6a and 6b are subjected to A / D conversion and formatting by the signal processing unit 7, and then transmitted to the ground as observation signals by a transmitter (not shown).

At the time of low-temperature calibration, the mesh driving mechanism 19a
1. The mesh roughness of the mesh-type reflector 18a is adjusted so that radio waves of a frequency desired to be received through the primary radiator 5 are transmitted, and the cosmic background radiation from the deep space 11 is used.
Transmit 7K. At this time, the mesh type reflecting mirror 18b adjusts the mesh roughness of the mesh so that the radio wave of the frequency received by the primary radiator 5 is transmitted by the mesh driving mechanism 19b. In this case, the cosmic background radiation from the deep space 11 passes through the mesh reflectors 18a and 18b and is received by the primary radiator 5. The received signal is transmitted to the ground by the same processing as the observation. At the time of the high-temperature calibration, the mesh roughness of the mesh-type reflecting mirror 18b is adjusted by the mesh driving mechanism 19b so that the radio wave of the frequency received by the primary radiator is reflected. At this time, the mesh roughness of the mesh-type reflecting mirror 18a is not particularly limited. By adjusting the coarseness of the mesh of the mesh-type reflecting mirror 18b and reflecting the radio wave of the frequency received by the primary radiator, the primary radiator 5 receives no external radio wave. Therefore, the radio wave received by the primary radiator 5 is only the thermal noise generated from the primary radiator 5. Primary radiator 5
Is equivalent to the physical temperature of the primary radiator 5, a radio wave corresponding to the physical temperature of the primary radiator 5 is input to the primary radiator 5. By controlling the physical temperature of the primary radiator 5 to 300 K using a heater,
A radio wave corresponding to K is input to the primary radiator 5 as a high-temperature calibration signal. The received signal is transmitted to the ground by the same processing as the observation.

In the above description, the case where the two frequencies separated by the group splitter 20 are observed and calibrated simultaneously has been described. However, the mesh roughness of the mesh-type reflecting mirrors 18a and 18b is adjusted and the group splitting is performed. Mesh driving mechanism 19 so that only one of the frequencies separated by the wave filter 20 is transmitted or reflected.
If a and 19b are driven, observation and calibration can be performed at different timings for each frequency separated by the group splitter. Also, here, the case where the frequency band has two frequencies has been described, but it goes without saying that the three frequencies may be the above-mentioned multiple frequencies.

[0044]

According to the first aspect of the present invention, a reflecting mirror for reflecting radio waves from the ground, a driving mechanism for driving the reflecting mirror, a reflecting mirror in front of the primary radiator, and a driving mechanism for driving the reflecting mirror When,
The provision of the primary radiator, the low-noise amplifier, and the signal processing unit enables input of low-temperature calibration noise without using a low-temperature calibration reflector. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Also, primary radiators,
Since there is no need to rotate the low-noise receiver and the signal processing unit together with the reflector, there is an effect that the rotation mechanism can be simplified.

Further, according to the second invention, a reflecting mirror for reflecting a radio wave from the ground, a driving mechanism for driving the reflecting mirror,
By including a high-temperature calibration source, a primary radiator, a low-noise amplifier, and a signal processing unit, it becomes possible to input low-temperature calibration noise without using a low-temperature calibration reflector.
There is an effect that observation without restriction of the observation width by the low-temperature calibration reflecting mirror can be performed. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing.

According to the third aspect of the invention, a reflector for reflecting radio waves from the ground, a low-temperature calibration source, a reflector and a reflector driving mechanism before the primary radiator, a primary radiator, a low-noise amplifier By providing the signal processing unit, it is possible to input high-temperature calibration noise without using a high-temperature calibration source, so that there is an effect that observation without restriction on the observation width by the high-temperature calibration source can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing.

According to the fourth aspect of the invention, the first single-polarization transmission type reflecting mirror for reflecting radio waves from the ground, the driving mechanism for changing the polarization direction of the first reflecting mirror, and the primary radiation A first single-polarized transmission mirror, a driving mechanism for changing the polarization direction of the second mirror, a primary radiator, a polarization splitter, a low-noise amplifier, and a signal processor. By providing the unit, it becomes possible to input low-temperature calibration noise without using a low-temperature calibration reflector. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Further, there is no need to rotate the primary radiator, the low-noise receiver, and the signal processing unit together with the reflecting mirror, so that there is an effect that the rotation mechanism can be simplified.

According to the fifth aspect of the present invention, the first single-polarization transmission type reflecting mirror for reflecting radio waves from the ground, the driving mechanism for changing the polarization direction of the first reflecting mirror, and the primary radiator Before the second
, A driving mechanism for changing the polarization direction of the second reflector, a primary radiator, a polarization splitter, and an RF
The provision of the switch, the low-noise amplifier, and the signal processing unit enables input of low-temperature calibration noise without using a low-temperature calibration reflector. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Further, there is no need to rotate the primary radiator, the low-noise receiver, and the signal processing unit together with the reflecting mirror, so that there is an effect that the rotation mechanism can be simplified. Furthermore, it is possible to switch and receive both horizontally and vertically received signals by the RF switch.

According to the sixth aspect of the invention, the first single-polarization transmission mirror for reflecting radio waves from the ground, the driving mechanism for changing the polarization direction of the first mirror, and the primary radiation A first single-polarized transmission mirror, a driving mechanism for changing the polarization direction of the second mirror, a primary radiator, a polarization splitter, a low-noise amplifier, and a signal processor. By providing the unit, it becomes possible to input low-temperature calibration noise without using a low-temperature calibration reflector. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Further, there is no need to rotate the primary radiator, the low-noise receiver, and the signal processing unit together with the reflecting mirror, so that there is an effect that the rotation mechanism can be simplified. Further, by providing a receiver for each polarization, it is possible to receive a reception signal of both horizontal and vertical polarizations.

According to the seventh aspect, the first mesh-type reflecting mirror for reflecting radio waves from the ground, the driving mechanism for changing the mesh roughness of the mesh of the first reflecting mirror, and the primary radiator A second mesh-type reflecting mirror, a second driving mechanism for changing the mesh size of the mesh of the second reflecting mirror, a primary radiator, a low-noise amplifier, and a signal processing unit. Accordingly, the low-temperature calibration noise can be input without using the low-temperature calibration reflector. In addition, since the beam is directed to the zenith direction at the time of low-temperature calibration, there is an effect that a clear field of view can be secured for the antenna beam at the time of low-temperature calibration, and the accuracy of low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Further, there is no need to rotate the primary radiator, the low-noise receiver, and the signal processing unit together with the reflecting mirror, so that there is an effect that the rotation mechanism can be simplified.

According to the eighth invention, the first mesh-type reflecting mirror for reflecting radio waves from the ground, the driving mechanism for changing the mesh roughness of the mesh of the first reflecting mirror, and the primary radiation A second mesh-type mirror in front of the vessel, a second drive mechanism for changing the coarseness of the mesh of the second mirror, a primary radiator, a group splitter, a low-noise amplifier, , The signal processing unit enables input of low-temperature calibration noise without using a low-temperature calibration mirror. Also, the beam points to the zenith direction during low-temperature calibration, so that a clear field of view can be secured for the antenna beam during low-temperature calibration.
There is an effect that the accuracy of the low-temperature calibration input can be improved. Further, since high-temperature calibration noise can be input without using a high-temperature calibration source, there is an effect that observation without restriction on the observation width can be performed. Further, the calibration timing can be set irrespective of the scanning cycle, and there is an effect that data can be acquired at the optimal calibration timing. Further, there is no need to rotate the primary radiator, the low-noise receiver, and the signal processing unit together with the reflecting mirror, so that there is an effect that the rotation mechanism can be simplified. Further, it is possible to observe the multi-frequency by the group splitter and to set the optimum calibration timing for each frequency.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a microwave radiometer according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which the microwave radiometer according to the first embodiment of the present invention is observed.

FIG. 3 is a diagram illustrating a time of low-temperature calibration of the microwave radiometer according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a state in which the microwave radiometer according to the first embodiment of the present invention is calibrated at a high temperature.

FIG. 5 is a diagram illustrating a configuration example of a microwave radiometer according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration example of a microwave radiometer according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration example of a microwave radiometer according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing polarization directions of a primary radiator and a reflector during observation, low-temperature calibration, and high-temperature calibration of a microwave radiometer according to Embodiment 4 of the present invention.

FIG. 9 is a diagram illustrating a configuration example of a microwave radiometer according to a fifth embodiment of the present invention.

FIG. 10 is a diagram illustrating a configuration example of a microwave radiometer according to a sixth embodiment of the present invention.

FIG. 11 is a diagram showing a configuration example of a microwave radiometer according to a seventh embodiment of the present invention.

FIG. 12 is a diagram illustrating a configuration example of a microwave radiometer according to an eighth embodiment of the present invention.

FIG. 13 is a diagram illustrating a configuration example of a conventional microwave radiometer.

FIG. 14 is a diagram showing a state in which a conventional microwave radiometer is observed.

FIG. 15 is a diagram showing a conventional microwave radiometer at the time of low-temperature calibration.

FIG. 16 is a diagram showing a conventional microwave radiometer at the time of high-temperature calibration.

FIG. 17 is a diagram showing observation timing of a conventional microwave radiometer.

[Explanation of symbols]

1 microwave radiometer, 2 observation mirror, 3 low temperature calibration mirror, 4 high temperature calibration source, 5 primary radiator, 6 low noise receiver, 7 signal processing unit, 8 rotating mechanism, 9 rotating unit, 10 earth , 11 deep space, 12 reflector, 13
Reflector driving mechanism, 14 single polarization transmission mirror, 15 single polarization reflector driving mechanism, 16 mesh type reflector, 17
Mesh drive mechanism, 18 polarization splitter, 19 RF switch, 20 group splitter.

Claims (8)

[Claims] 1. A microwave radiometer mounted on a satellite for observing the earth's surface, a first reflector for reflecting microwave noise radio waves from the earth's surface, and a beam of the first reflector. A first driving mechanism for switching a direction between the earth direction and a deep space direction in which cosmic background radiation can be observed, a primary radiator for receiving a radio wave reflected by the first reflecting mirror, and a first radiator; A second reflector positioned between the reflector and the primary radiator for blocking an input to the primary radiator; and a second reflector for driving the second reflector, A second drive mechanism for switching the radio wave input to pass or cut off, a low noise amplifier for amplifying, detecting and integrating the received signal, and an A of the detected received signal
And a signal processing unit for performing / D conversion and formatting. 2. A microwave radiometer mounted on a satellite for observing the earth's surface, comprising: a reflecting mirror for reflecting microwave noise radio waves from the earth's surface; A driving mechanism for switching to a deep space direction in which background radiation can be observed, a primary radiator for receiving radio waves reflected by the first reflector, a high-temperature calibration source, and the first reflector. A second radiator located between the primary radiator and the input to the primary radiator;
And a second driving mechanism for driving the second reflecting mirror to switch the radio wave input to the primary radiator to pass or cut off, and a low drive for amplifying, detecting and integrating the received signal. A noise amplifier and A / D of the detected received signal
A signal processing unit for performing conversion and formatting, and a rotation driving unit for rotating and driving an apparatus other than the high-temperature calibration source and switching between an input from the high-temperature calibration source and an input from the reflecting mirror. Features microwave radiometer. 3. A microwave radiometer mounted on a satellite for observing the earth's surface, comprising: a first reflector for reflecting microwave noise radio waves from the earth's surface; A primary radiator for receiving the received radio wave, a second reflector positioned between the first reflector and the primary radiator, and driving the second reflector to form the primary radiation A drive mechanism for switching the input of radio waves to the detector in the deep space direction or the cutoff of radio wave input where radio waves or space background radiation from the first reflector can be observed, and low noise for amplifying, detecting and integrating the received signal A microwave radiometer comprising: an amplifier; and a signal processing unit for performing A / D conversion and formatting of the detected reception signal. 4. A microwave radiometer mounted on a satellite for observing the earth's surface, which reflects only one horizontal or vertical polarization for reflecting microwave noise radio waves from the earth's surface and the other polarization. Waves are reflected by a first single-polarized transmission mirror, a first driving mechanism for switching the polarization direction of the first mirror, and the first single-polarized transmission mirror. A primary radiator for receiving the transmitted radio wave, a second single-polarization transmission reflector located between the first single-polarization transmission reflector and the primary radiator, A second drive mechanism for driving the single-polarization transmission type reflecting mirror, switching the transmission polarization direction, and switching between passing or blocking the input of radio waves to the primary radiator, and a horizontal and vertical Polarization splitter for separating polarization, low noise for amplification, detection and integration of received signal A microwave radiometer comprising: an amplifier; and a signal processing unit for performing A / D conversion and formatting of the detected reception signal. 5. An RF for switching the polarization of a received signal.
5. The microwave radiometer according to claim 4, further comprising a switch. 6. The microwave radiometer according to claim 4, wherein a receiver for each polarization is added. 7. A microwave radiometer mounted on a satellite for observing the earth's surface, wherein the mesh for reflecting microwave noise radio waves from the earth's surface has a variable mesh roughness. A first mesh-type reflecting mirror whose frequency of transmission and reflection is variable, a first driving mechanism for switching the mesh roughness of the mesh of the first reflecting mirror, and a radio wave reflected by the reflecting mirror A first mesh radiator for receiving the first and second mesh-type reflectors located between the first mesh-type reflector and the primary radiator;
A second drive mechanism for switching the mesh coarseness of the mesh and switching the radio wave input to the primary radiator to pass or cut off, and a switch for performing amplification, detection, and integration of a reception signal of only one polarization. A microwave radiometer comprising: a polarization low-noise amplifier; and a signal processing unit for performing A / D conversion and formatting of the detected reception signal. 8. The microwave radiometer according to claim 7, further comprising a group splitter for splitting a received signal according to a frequency, and a receiver for each frequency.