JP5611113B2 - Temperature control method of high-temperature calibration source for microwave radiometer - Google Patents

Description

  The present invention relates to a temperature control method for a high-temperature calibration source for a microwave radiometer mounted on a spacecraft such as an artificial satellite.

  Conventionally, a structure that is rotatably mounted on a satellite, a main reflector that reflects observation microwaves that are fixed to the structure and incident from an observation target, and a low temperature that is fixed to the satellite and incident from deep space Low-temperature calibration reflector that reflects the calibration microwave, high-temperature calibration source that is fixed to the satellite and emits the high-temperature calibration microwave, and observation that is fixed to the structure and reflected by the main reflector There is known a microwave radiometer including a microwave, a low-temperature calibration microwave reflected by a low-temperature calibration reflector, and a primary radiator that receives a high-temperature calibration microwave emitted by a high-temperature calibration source.

  The high-temperature calibration source includes a radio wave absorber that emits microwaves for high-temperature calibration, a temperature sensor that detects the temperature of the radio wave absorber, a heater attached to the radio wave absorber, and a heater that controls the supply of power to the heater. And a control device. The heater control device compares the temperature detected by the temperature sensor with the target temperature every unit time. If the temperature detected by the temperature sensor is lower than the target temperature, it continues to supply power to the heater for the unit time. When the temperature detected by the temperature sensor is higher than the target temperature, the supply of power to the heater is stopped for a unit time. Thereby, the temperature of the electromagnetic wave absorber becomes a temperature close to the target temperature (see, for example, Patent Document 1).

JP 2006-162287 A

  However, in the conventional microwave radiometer, the power is always supplied to the heater for a unit time, or the power supply to the heater is always stopped, so that the temperature of the radio wave absorber is centered on the target temperature. Overshoot and temperature fluctuation (hunting) occur, and the temperature of the radio wave absorber cannot be controlled with high accuracy.

  The present invention provides a temperature control method for a high-temperature calibration source for a microwave radiometer that can control the temperature of a radio wave absorber with higher accuracy.

A method for controlling a temperature of a high-temperature calibration source for a microwave radiometer according to the present invention includes a structure that is rotatably provided to a base, and is fixed to the structure, and reflects an observation microwave from an observation target. A primary reflector, a primary radiator fixed to the structure, the primary body that rotates and moves as the structure rotates and receives the observation microwave reflected by the main reflector, and fixed to the base A low-temperature calibration reflector that reflects low-temperature calibration microwaves from deep space and makes the low-temperature calibration microwaves incident on the primary radiator located at a low-temperature calibration position, and is fixed to the base, A high-temperature calibration source that emits a high-temperature calibration microwave and causes the high-temperature calibration microwave to be incident on the primary radiator located at a high-temperature calibration position, and the high-temperature calibration source is located at the high-temperature calibration position. A storage box in which an opening facing the radiator is formed; a radio wave absorber that is provided inside the storage box and radiates the high-temperature calibration microwave; and a heat insulating material that covers the outside of the storage box; A first heating device that heats the radio wave absorber when power is supplied; a first switch that opens and closes a circuit that supplies power to the first heating device; and a temperature of the radio wave absorber. A temperature detection device that detects the temperature, and a temperature control device that controls the first switch based on the temperature detected by the temperature detection device so that the temperature of the radio wave absorber becomes a target temperature. The temperature of the observation target is measured using the intensity value of the observation microwave received by the detector, the intensity value of the cryogenic calibration microwave received by the primary radiator, and the temperature of the deep space. Value and the primary radiator receives Using the intensity value of the microwave for high temperature calibration and the value of the detected temperature of the temperature detection device at that time, the intensity value of the observation microwave received by the primary radiator is measured. A temperature control method of a high-temperature calibration source for a microwave radiometer, which is a control method of the high-temperature calibration source in a microwave radiometer that calibrates a temperature value of an observation object, and based on a difference between the detected temperature and the target temperature A supply power amount calculation step of calculating the supply power amount to the first heating device every unit time, and dividing the unit time into a plurality of divided times, and a plurality of power supplies to the first heating device. with power supply pattern table determined in accordance with power supplied pattern to the supply amount of power distributed among the segment time is the unit time, in response to said amount of power supply, the first for each of the divided time Sui And a switch control process for controlling the switch.

  According to the temperature control method of the high-temperature calibration source for a microwave radiometer according to the present invention, the first method for heating the radio wave absorber from the difference between the detected temperature of the temperature detector for detecting the temperature of the radio wave absorber and the target temperature. Supply power amount calculation step for calculating the amount of power supplied to the heating device every unit time, and switch control for controlling the first switch for each divided time divided into a plurality of unit times according to the calculated supply power amount Therefore, compared with the case where the first switch is controlled every unit time, the amount of power supplied to the first heating device can be made closer to the calculated amount of supplied power. As a result, the temperature of the radio wave absorber can be controlled with higher accuracy.

It is a perspective view which shows the microwave radiometer which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the high-temperature calibration source main body and thermal control panel apparatus of FIG. It is a block diagram which shows the principal part of the microwave radiometer of FIG. It is a figure which shows the time change of the electric power supplied to the 1st heating apparatus of FIG. 3, and the time change of the temperature of a radio wave absorber. It is a figure which shows the 1st supply electric power pattern table memorize | stored in the temperature control apparatus of FIG. It is a figure which shows the time change of the electric power supplied to a heating apparatus by the conventional apparatus. It is a figure which shows the time change of the electric power supplied to the 1st heating apparatus by the electric power supply control apparatus of FIG. It is a flowchart which shows operation | movement of the temperature control apparatus of FIG. It is a figure which shows the time change of the measured value of the temperature of the electromagnetic wave absorber of FIG. It is a figure which shows the time change of the actual value of the electric energy supplied to the 1st heating apparatus of FIG. It is a figure which shows the modification of the 1st power supply pattern table of FIG. It is a figure which shows the 1st supply electric power pattern table memorize | stored in the temperature control apparatus of the microwave radiometer which concerns on Embodiment 2. FIG. It is a figure which shows the time change of the electric power supplied to a 1st heating apparatus by the 1st supply electric power pattern table of FIG. FIG. 6 is a configuration diagram showing a main part of a microwave radiometer according to a third embodiment. It is a figure which shows the 1st supply electric power pattern table memorize | stored in the temperature control apparatus of FIG. It is a figure which shows the 2nd supply electric power pattern table memorize | stored in the temperature control apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding members and parts will be described with the same reference numerals.

Embodiment 1 FIG.
1 is a perspective view showing a microwave radiometer according to Embodiment 1 of the present invention. In the figure, the microwave radiometer receives the observation microwave radiated from the observation object such as the earth surface and the atmosphere, and measures the wavelength component of this observation microwave, thereby the amount of water vapor, sea surface temperature, This is a luminance temperature distribution measuring device for the purpose of calculating the distribution of physical quantities such as sea ice density.

  The microwave radiometer includes a structure 2 attached to an artificial satellite (base) 1, a connecting rod 3 of a truss structure attached to the structure 2, and a main reflector that reflects observation microwaves radiated from an observation target. 4, a low-temperature calibration reflector 5 that reflects low-temperature calibration microwaves emitted from deep space, and a high-temperature calibration source body 6 that emits high-temperature calibration microwaves. The microwave radiometer includes an observation microwave reflected by the main reflector 4, a low-temperature calibration microwave reflected by the low-temperature calibration reflector 5, and a high-temperature calibration microwave emitted by the high-temperature calibration source body 6. A primary radiator 7 for receiving waves and a thermal control panel device 8 for heating the high-temperature calibration source body 6 are provided.

  The structure 2 is rotatable with respect to the artificial satellite 1 about a rotation center axis 9 passing through the center of the structure 2. The structure 2 is provided with a power supply control device 20 that supplies power to the high-temperature calibration source body 6 and the thermal control panel device 8.

  The high-temperature calibration source body 6, the thermal control panel device 8, and the power supply control device 20 constitute a high-temperature calibration source 100.

  The main reflecting mirror 4 is fixed to the structure 2 via the connecting rod 3. Therefore, the main reflecting mirror 4 rotates around the rotation center axis 9 in conjunction with the rotation of the structure 2.

  Each of the low-temperature calibration reflector 5 and the high-temperature calibration source body 6 is fixed to the artificial satellite 1. Accordingly, the relative positions of the low-temperature calibration reflector 5 and the high-temperature calibration source body 6 with respect to the structure 2 change as the structure 2 rotates.

  The primary radiator 7 is fixed with respect to the structure 2. Therefore, the primary radiator 7 rotates around the rotation center axis 9 in conjunction with the rotation of the structure 2. The position of the primary radiator 7 includes the observation position where the primary radiator 7 receives the observation microwave reflected by the main reflector 4 as the primary radiator 7 rotates about the rotation center axis 9, and the low-temperature calibration reflector 5. The low-temperature calibration position for receiving the low-temperature calibration microwave reflected by the high-temperature calibration source body 6 and the high-temperature calibration position for receiving the high-temperature calibration microwave radiated by the high-temperature calibration source body 6 are changed.

  The thermal control panel device 8 is fixed to the structure 2 so as to be disposed between the structure 2 and the high-temperature calibration source body 6. The thermal control panel device 8 is formed in an annular shape. The thermal control panel device 8 is arranged so that the rotation center axis 9 passes through the center of the thermal control panel device 8. The thermal control panel device 8 rotates about the rotation center axis 9 in conjunction with the rotation of the structure 2.

  FIG. 2 is a longitudinal sectional view showing the high-temperature calibration source body 6 and the thermal control panel device 8 of FIG. The high-temperature calibration source body 6 includes a storage box 61 fixed to the artificial satellite 1 (FIG. 1), a plurality of radio wave absorbers 62 stored in the storage box 61, and a radio wave that detects the temperature of the radio wave absorber 62. The absorber temperature sensor 63, a plurality of storage box heaters 64 for heating the storage box 61, a plurality of storage box temperature sensors 65 for detecting the temperature of the storage box 61, and a heat insulating material that covers the storage box 61 from the outside. And an MLI (Multilayer Insulator) 66.

  The storage box 61 includes a top plate 611 that is provided apart from the structure 2 and serves as a ceiling portion of the storage box 61, and four side plates 612 that extend from the top plate 611 toward the structure 2 and serve as side walls of the storage box 61. It is configured. That is, the shape of the storage box 61 is a hollow rectangular parallelepiped shape in which the opening 613 is formed on the structure 2 side. The storage box 61 is disposed such that the opening 613 faces the thermal control panel device 8. In addition, even if the thermal control panel device 8 rotates in conjunction with the rotation of the structure 2, the storage box 61 has the opening 613 always facing the thermal control panel device 8.

  The wave absorber 62 has a quadrangular pyramid shape. The radio wave absorber 62 is fixed to the top plate 611 so that the bottom surface of the radio wave absorber 62 is in surface contact with the top plate 611. In addition, the radio wave absorber 62 is arranged so that the tip of the radio wave absorber 62 is directed to the opening 613. The material constituting the radio wave absorber 62 is a dielectric material. Therefore, unnecessary reflection of radio waves by the radio wave absorber 62 is suppressed.

  The radio wave absorber temperature sensor 63 is attached to the surface of the radio wave absorber 62. The radio wave absorber temperature sensor 63 may be attached inside the radio wave absorber 62.

  The storage box heater 64 and the storage box temperature sensor 65 are respectively attached to the top plate 611 and the side plate 612. Each of the storage box heater 64 and the storage box temperature sensor 65 is arranged outside the storage box 61. Each of the storage box heater 64 and the storage box temperature sensor 65 is arranged so as to be sandwiched between the storage box 61 and the MLI 66. The storage box heater 64 and the storage box temperature sensor 65 may be disposed inside the storage box 61.

  The radio wave absorber 62 is heated when the storage box heater 64 heats the storage box 61. That is, the storage box heater 64 indirectly heats the radio wave absorber 62. Since the storage box heater 64 heats the radio wave absorber 62 through the storage box 61, it is possible to suppress variations in the temperature of the radio wave absorber 62 as compared with the case where the radio wave absorber 62 is directly heated. . Heat exchange is performed between the storage box 61 and the radio wave absorber 62 by heat conduction or radiation. Therefore, the storage box temperature sensor 65 detects the temperature of the radio wave absorber 62 via the storage box 61. That is, the storage box temperature sensor 65 indirectly detects the temperature of the radio wave absorber 62.

  The MLI 66 uses silver-deposited PEI (polyetherimide) having a low sunlight absorption rate as the outermost layer. Thereby, the temperature rise of MIL66 by sunlight entering MLI66 is controlled. Note that the outermost layer of the MLI 66 is not limited to silver vapor deposition PEI, and for example, silver vapor deposition Teflon (Teflon is a registered trademark) may be used. Since the MLI 66 covers the storage box 61, the storage box heater 64, and the storage box temperature sensor 65, the heat of sunlight is suppressed from affecting the storage box 61, the storage box heater 64, and the storage box temperature sensor 65. The heat of the storage box 61, the storage box heater 64 and the storage box temperature sensor 65 is prevented from leaking into deep space.

  The thermal control panel device 8 includes a thermal control panel main body 81, a plurality of thermal control panel heaters 82 that heat the thermal control panel main body 81, a thermal control panel temperature sensor 83 that detects the temperature of the thermal control panel main body 81, and a structure. 2 and a spacer 84 of a heat insulating material that supports the heat control panel main body 81. Each of the thermal control panel heater 82 and the thermal control panel temperature sensor 83 is attached to the surface of the thermal control panel main body 81 on the structure 2 side. The thermal control panel heater 82 and the thermal control panel temperature sensor 83 may be attached to the surface of the thermal control panel main body 81 on the radio wave absorber 62 side.

  The thermal control panel body 81 is surface-treated with a white paint having a low solar absorptance and a high infrared emissivity. Thereby, the temperature rise of the thermal control panel body 81 when sunlight enters the thermal control panel body 81 is suppressed.

  The radio wave absorber 62 is heated when the heat control panel heater 82 heats the heat control panel main body 81. That is, the thermal control panel heater 82 indirectly heats the radio wave absorber 62. Since the thermal control panel heater 82 heats the radio wave absorber 62 via the thermal control panel main body 81, the variation in temperature of the radio wave absorber 62 is suppressed as compared with the case where the radio wave absorber 62 is directly heated. be able to. Heat exchange is performed between the radio wave absorber 62 and the heat control panel main body 81 by radiation. Therefore, the thermal control panel temperature sensor 83 detects the temperature of the radio wave absorber 62 via the thermal control panel main body 81. That is, the thermal control panel temperature sensor 83 indirectly detects the temperature of the radio wave absorber 62.

  Since the spacer 84 is disposed between the structure 2 and the heat control panel main body 81, the heat of the structure 2 may affect the heat control panel main body 81, the heat control panel heater 82, and the heat control panel temperature sensor 83. In addition, the heat of the thermal control panel body 81, the thermal control panel heater 82, and the thermal control panel temperature sensor 83 is suppressed from leaking to the structure 2. Thereby, the temperature of the thermal control panel main body 81 can be controlled independently from the structure 2.

  The storage box heater 64 and the thermal control panel heater 82 are configured by members that can heat the member to be heated by supplying electric power, such as an electric heater or a Peltier element.

  FIG. 3 is a block diagram showing a main part of the microwave radiometer of FIG. In the figure, a first heating device 101 for heating the radio wave absorber 62 is constituted by the storage box heater 64 (FIG. 1) and the thermal control panel heater 82 (FIG. 1). The storage box temperature sensor 65 and the thermal control panel temperature sensor 83 constitute a temperature detection device 102 that detects the temperature of the radio wave absorber 62. The power supply control device 20 includes a power supply device 21 that supplies power to the first heating device 101, and a first switch 22 that opens and closes a circuit that supplies power from the power supply device 21 to the first heating device 101. And a temperature control device 23 for controlling the first switch 22. When the state of the first switch 22 is ON, power is supplied from the power supply device 21 to the first heating device 101, and when the state of the first switch 22 is OFF state, the first heating is performed from the power supply device 21. The supply of power to the apparatus 101 is stopped.

  A temperature detected by the temperature detection device 102 is input to the temperature control device 23. A temperature control program 231 for controlling the first switch 22 is incorporated in the temperature control device 23. The temperature control device 23 sets the state of the first switch 22 to the ON state or the OFF state based on the temperature detected by the temperature detection device 102 so that the temperature of the radio wave absorber 62 becomes the target temperature by the temperature control program 231. ON / OFF control which is switching control is performed. The temperature control device 23 can control the temperatures of the top plate 611 (FIG. 2), the side plate 612 (FIG. 2), and the thermal control panel body 81 (FIG. 2) independently.

  Next, calibration of the microwave radiometer will be described. As shown in FIG. 1, the structure 2 rotates about the rotation center axis 9 with respect to the artificial satellite 1 at a speed of one rotation per 1.5 seconds. As a result, the primary radiator 7 moves around the rotation center axis 9, and the main reflector 4 and the thermal control panel device 8 further rotate around the rotation center axis 9.

  When the primary radiator 7 moves and the position of the primary radiator 7 reaches the high temperature calibration position, the primary radiator 7 receives the high temperature calibration microwave radiated from the high temperature calibration source body 6. Thereafter, when the primary radiator 7 moves and the position of the primary radiator 7 becomes the low-temperature calibration position, the primary radiator 7 receives the low-temperature calibration microwave reflected by the low-temperature calibration reflector 5. To do.

  The microwave radiometer includes the intensity value of the microwave for high temperature calibration received by the primary radiator 7, the temperature value of the radio wave absorber 62 detected by the radio wave absorber temperature sensor 63 at that time, and the primary radiator 7. The correlation value between the intensity of the observation microwave and the temperature of the observation object is calculated using the value of the intensity of the low-temperature calibration microwave received and the value of the deep space temperature.

  The microwave radiometer calibrates the temperature value of the observation target measured from the intensity value of the observation microwave received by the primary radiator 7 using the calculated correlation equation. While the structure 2 makes one revolution, the primary radiator 7 receives the observation microwave, the high-temperature calibration microwave, and the low-temperature calibration microwave, and thus the observation microwave received by the primary radiator 7 The temperature value of the observation object measured from the intensity value is calibrated repeatedly every 1.5 seconds. Thereby, the accuracy of the temperature of the observed object to be measured is improved.

  Next, control of power supply to the first heating device 101 will be described. FIG. 4 is a diagram showing a time change of the power supplied to the first heating device 101 of FIG. 3 and a time change of the temperature of the radio wave absorber 62. FIG. 4 shows the temperature detected by the temperature detection device 102 at an arbitrary time and the power supplied to the first heating device 101. The temperature control device 23 (FIG. 3) calculates the amount of power supplied to the first heating device 101 (FIG. 3) every unit time Δt. Hereinafter, the unit time Δt is referred to as a frame. One frame is further divided into i pieces. Hereinafter, the divided part is referred to as a segment. The length (time) of each segment is Δt / i.

  In this example, the numbers of three consecutive frames are n-1, n, and n + 1. However, n is an arbitrary natural number. The array names and variable names used in this example are only examples, and any other array name or variable name may be used. In this example, the description will be made using an array such as T (n) having one variable. This is for ease of explanation, and if there is no problem in the program, a plurality of variables are selected. Even if it is the arrangement | sequence used, there is no problem.

  The temperature detected by the temperature detector 102 (FIG. 3) is sampled at each sample time n−1, n, n + 1..., Which is the start time of each frame, and input to the temperature controller 23. Here, the time is measured by time information from the artificial satellite 1. Note that the time measurement is not limited to this, and for example, a time measurement device may be provided in the temperature control device 23, and time measurement by the time measurement device may be performed.

The temperature control device 23 sends a signal to the first switch 22 based on the preset target temperature T ₀ and the temperature detected by the temperature detection device 102 by the temperature control program 231, and the first heating from the power supply device 21. Controls the supply of power to the apparatus 101.

  Here, the state of the first switch 22 is an ON state in which power is supplied from the power supply device 21 to the first heating device 101 and power supply from the power supply device 21 to the first heating device 101. Since only one of the OFF state to be cut off is provided, the power supplied from the power supply device 21 to the first heating device 101 is either 0% or 100% of the power of the power supply device 21.

  The operation of the temperature control device 23 is basically similar to the operation by a general PID control program. In the present invention, the amount of power supplied to the first heating device 101 is calculated for each frame at each sample time n, and the first switch 22 is controlled for each segment according to the calculated amount of supplied power. As described above, it is characterized by being patterned in advance.

The temperature control device 23 is set with a target temperature T ₀ , gain K _P , integration time τ _I , and differentiation time τ _D , which are temperature control parameters. Although the values of these temperature control parameters have optimum values, they need to be optimized for each temperature control case because they differ depending on the heat capacity and heat dissipation characteristics of the radio wave absorber 62.

The temperature control device 23 determines the difference (deviation) e _n−2 , e _n−1 , e _n between the target temperature T ₀ and the temperature detected by the temperature detection device 102 at each sample time n−2, n−1, and _n. It calculates, using the calculated difference _{e n-2, e n-1, e n,} the following equation (1), (2), the amount of power supplied to the first heating device 101 in the frame n Q _n is calculated.

Q _n = Q _n-1 + ΔQ _n (1)
_{ΔQ n = KP {(e n} -e n-1) + (Δt / τ I) e n + (ΔD / Δt) (e n -2e n-1 + e n-2)} (2)

  The temperature control device 23 stores a first supply power pattern table for the first switch 22. FIG. 5 is a diagram showing a first supply power pattern table stored in the temperature control device 23 of FIG. In this example, the number of segments per frame is i = 5. The accuracy of temperature control by the temperature control device 23 improves as the number of segments increases. The upper limit value of the number of segments is determined by the processing capacity of the temperature control device 23, the switching speed of the first switch 22, and the like.

In the figure, Q _max is when power is supplied to the first heating device 101 over the entire time of one frame, that is, when the state of the first switch 22 is ON in all the segments. This is the amount of power supplied per frame. Therefore, Q _max is the maximum amount of power that can be supplied to the first heating apparatus 101 in one frame.

According to the ratio between the supplied power amount Q _n and the maximum supplied power amount Q _max calculated from the above formulas (1) and (2), the first power is supplied to the first heating device 101 in each segment. A supply power pattern is determined from the first supply power pattern table. In this example, in the first power supply pattern, as the value of Q _n / Q _max increases, the number of segments that turn the first switch 22 in the ON state increases from 0 by one. The number of patterns of the first supply power pattern is the number of segments + 1, and in this example, the number of patterns is 6.

  FIG. 6 is a diagram showing the time change of the power supplied to the heating device by the conventional device, and FIG. 7 is a diagram showing the time change of the power supplied to the first heating device 101 by the power supply control device 20 of FIG. is there. 6 and 7 show the average power for each frame. In the conventional apparatus, a switch that opens and closes a circuit that supplies power to the heating apparatus is controlled for each frame. Therefore, in the frame in which power is supplied to the heating device, power is always supplied to the heating device. That is, the average value of the supplied power in the frame is 100% of the power of the power supply device 21. Further, in a frame in which power is not supplied to the heating device, the average value of the supplied power is 0% of the power of the power supply device 21.

On the other hand, in the power supply control device 20, the first switch 22 is controlled for each segment into which the frame is divided. Therefore, the average value of the power supplied to the first heating device 101 for each frame has an intermediate value between 0% and 100% of the power of the power supply device 21 unlike the conventional device. That is, by controlling the first switch 22 for each segment, the amount of power supplied to the first heating device 101 can be brought close to the calculated amount of supplied power Q _n , and general PID control can be performed. Similar temperature control of the electromagnetic wave absorber 62 is possible. As a result, temperature overshoot and temperature fluctuation (hunting) of the radio wave absorber 62 are less likely to occur, so that the temperature of the radio wave absorber 62 can be controlled with high accuracy.

  FIG. 8 is a flowchart showing the operation of the temperature control device 23 of FIG. First, the sampling time interval Δt, which is the frame length, and the number of segments i per frame are determined (step S1). Further, since the detected temperatures of the temperature detecting device 102 at the sample times n−2, n−1, and n are input, T (n−2), T (n−1), and T (n) are arrayed. The initial value is input to T (n-2) and T (n-1) (step S2). Here, there is no problem even if the initial value input to T (n-2) and T (n-1) is any temperature.

Next, it is determined whether or not the target temperature T ₀ , the gain K _P , the integration time τ _I , and the differentiation time τ _D that are temperature control parameters used by the temperature control device 23 are changed (step S3). When the temperature control parameter is changed in S3, the target temperature T ₀ , gain K _P , integration time τ _I , and differentiation time τ _D are input (step S4). If there is no change in the temperature control parameter in step S3, step S4 is omitted and the process proceeds to the next.

  Thereafter, the temperature control device 23 reads the temperature detected by the temperature detection device 102 (step S5), and further, the temperature control device 23 reads the current time TIME from the artificial satellite 1 (step S6). Thereafter, the temperature control device 23 determines whether or not the sample time interval Δt has elapsed from the previous sample time n−1 (step S7). If the temperature control device 23 determines in step S7 that the sample time interval Δt has not elapsed since the previous sample time n-1, the process returns to step S5.

  On the other hand, if the temperature controller 23 determines in step S7 that the sample time interval Δt has elapsed from the previous sample time n−1 in step S7, the time that has passed the sample time interval Δt from the sample time n−1. Is the sample time n, the temperature detected by the temperature detection device 102 at the sample time n is entered in T (n), and the sample time n is entered in the variable STIME (step S8).

Thereafter, the target temperature T ₀ at each sample time n−2, n−1, n and T (n−2), T, which are detected temperatures of the temperature detection device 102 at each sample time n−2, n−1, n. (n-1), each of the difference between T (n) a (deviation) and _{e n-2, e n-} 1, e n ( step S9), and power supply to the first heating device 101 in the frame n wherein the amount _{Q n} of the (1), determined from the equation (2) (supplied electric power amount calculation step) (step S10, step S11).

By the ratio of the supply power amount Q _n and the maximum amount of power supply Q _max obtained, the first power supply pattern is determined (step S12), the each segment, the first switch 22 is controlled (switch control step ), Electric power is supplied to the first heating device 101 (step S13). Finally, the value of T (n-1) is input to T (n-2), the value of T (n) is input to T (n-1) (step S14), and the process returns to step S3.

FIG. 9 is a diagram showing a change over time of the measured value of the temperature of the radio wave absorber 62 in FIG. 3, and FIG. 10 is a diagram showing a change over time in the measured value of the power supply amount Q _n supplied to the first heating device 101 in FIG. It is. FIG. 9 shows the difference (deviation) e between the temperature of the radio wave absorber 62 and the target temperature T _0, and FIG. 10 shows the power supply amount Q _n and the maximum power supply amount Q to the first heating device 101 per frame. A value obtained by multiplying the ratio with _max by 100 is shown.

9 and 10, the response when heat is applied to the radio wave absorber 62 from the outside at time 0 seconds is measured. As shown in FIG. 9, the difference between the temperature of the radio wave absorber 62 and the target temperature T ₀ is within ± 0.2 K regardless of whether heat is input to the radio wave absorber 62 from the outside. The temperature of the radio wave absorber 62 is controlled with high accuracy by the supply control device 20. As shown in FIG. 10, after the external heat input, a decrease in the value of Q _n / Q _max is seen, the temperature rise of the radio wave absorber 62 due to heat input from the outside is suppressed, and the radio wave absorber 62 Temperature control is performed normally. The value of Q _n / Q _max × 100 per frame takes an intermediate value of 0 to 100, and is either 0 or 100 as in the conventional device that opens and closes a circuit that supplies power to the heating device for each frame. It turns out that it doesn't take.

As described above, according to the microwave radiometer according to the first embodiment of the present invention, the temperature control device 23 is based on the difference between the temperature detected by the temperature detection device 102 and the target temperature T _0. The power supply amount Q _n to the frame 101 is calculated for each frame, and the first switch 22 is controlled for each segment according to the calculated power supply amount Q _n , so the first switch 22 is controlled for each frame. If compared with the amount of power supplied to the first heating device 101, the calculated can be made closer to the supply power amount Q _n. As a result, the temperature of the radio wave absorber 62 can be controlled with higher accuracy.

According to the temperature control method of the high-temperature calibration source for the microwave radiometer according to the present invention, the first heating is performed based on the temperature difference between the detected temperature of the temperature detector 102 that detects the temperature of the radio wave absorber 62 and the target temperature T _0. It includes a supply power amount calculating step of calculating the supply power amount Q _n to the apparatus 101 for each frame, calculated in accordance with the supply power amount Q _n, and a switch control step of controlling the first switch 22 for each segment since it has, as compared with the case of controlling the first switch 22 for each frame, the amount of power supplied to the first heating device 101 can be brought close to the supply power amount Q _n calculated. As a result, the temperature of the radio wave absorber 62 can be controlled with higher accuracy.

In the first embodiment, the first supply power pattern table in which the value of Q _n / Q _max is divided as 0 to 0.2, 0.2 to 0.4, etc. is used. For example, as shown in FIG. 11, the first supply power pattern table obtained by dividing the value of Q _n / Q _max as 0 to 0.1, 0.1 to 0.3,... There is no particular problem, and the method of dividing the value of Q _n / Q _max is arbitrary. However, the temperature control accuracy can be improved by dividing the value of Q _n / Q _max evenly.

Embodiment 2. FIG.
FIG. 12 is a diagram illustrating a first supply power pattern table stored in the temperature control device 23 of the microwave radiometer according to the second embodiment, and FIG. 13 is a diagram illustrating the first supply power pattern table of FIG. It is a figure which shows the time change of the electric power supplied to the heating apparatus 101 of this. In the first supply power pattern in which there are a plurality of segments to which power is supplied to the first heating device 101, the segments to which power is supplied to the first heating device 101 are evenly distributed in the frame. That is, when there are a plurality of segments in which the first switch 22 is in the ON state in the same frame, each segment in which the first switch 22 is in the ON state is biased in the same frame. Is arranged so that there is no. Other configurations are the same as those in the first embodiment. Note that the first supply power pattern may be any supply power pattern as long as segments to which power is supplied to the first heating apparatus 101 are evenly distributed in the frame.

  As described above, according to the temperature control method of the high-temperature calibration source for a microwave radiometer according to the second embodiment of the present invention, the plurality of segments to which electric power is supplied to the first heating device 101 is a frame. In the frame, power is distributed and supplied to the first heating device 101 in the frame. Thereby, the temperature fluctuation (hunting) of the radio wave absorber 62 is reduced, and the temperature of the radio wave absorber 62 can be controlled with higher accuracy than the microwave radiator according to the first embodiment.

Embodiment 3 FIG.
FIG. 14 is a configuration diagram showing a main part of the microwave radiometer according to the third embodiment. In the figure, the high-temperature calibration source 100 further includes a second heating device 103 that heats the radio wave absorber 62. The second heating device 103 may indirectly heat the radio wave absorber 62 like the first heating device 101, or, unlike the first heating device 101, the radio wave absorber 62 directly. May be heated. The calorific value of the second heating device 103 is approximately 1/5 of the calorific value of the first heating device 101.

  The power supply device 21 supplies power to the second heating device 103. The power supply control device 20 further includes a second switch 24 that opens and closes a circuit that supplies power from the power supply device 21 to the second heating device 103. When the state of the second switch 24 is ON, power is supplied from the power supply device 21 to the second heating device 103, and when the state of the second switch 24 is OFF, the second heating is performed from the power supply device 21. The supply of power to the device 103 is stopped. The temperature control device 23 sets each of the first switch 22 and the second switch 24 according to the temperature control program 231 so that the temperature of the radio wave absorber 62 becomes the target temperature based on the temperature detected by the temperature detection device 102. ON / OFF control. The temperature control device 23 stores a first supply power pattern table for the first switch 22 and a second supply power pattern table for the second switch 24. The temperature control program 231 controls both the first switch 22 and the second switch 24.

15 shows a first supply power pattern table stored in the temperature control device 23 of FIG. 14, and FIG. 16 shows a second supply power pattern table stored in the temperature control device 23 of FIG. FIG. The first power supply pattern in which electric power is supplied to the first heating device 101, similarly as in the first embodiment, is determined by the ratio of the supply power amount Q _n and the maximum supply power amount Q _max.

The number of second supply power patterns in which power is supplied to the second heating device 103 is 30, which is larger than the number of patterns of the first supply power pattern. The second power supply pattern, similarly to the first power supply pattern is determined by the ratio of the supply power amount Q _n and the maximum supply power amount Q _max. The smaller the heat generation amount of the second heating device 103 with respect to the heat generation amount of the first heating device 101, the larger the number of patterns of the second supply power pattern. Thereby, the second supply power pattern can be detailed.

  The temperature control device 23 controls the temperature of the radio wave absorber 62 by combining the first heating device 101 and the second heating device 103. Other configurations are the same as those in the first embodiment. As in the second embodiment, a plurality of segments to which power is supplied to the first heating device 101 and a plurality of segments to which power is supplied to the second heating device 103 are dispersed in the frame. It may be a configuration.

As described above, according to the temperature control method of the high-temperature calibration source for a microwave radiometer according to the third embodiment of the present invention, the high-temperature calibration source 100 heats the radio wave absorber 62 by supplying power. A second heating device 103 that generates less heat than the first heating device 101, and a second switch 24 that opens and closes a circuit that supplies power to the second heating device 103, and further calculates a supply power amount. In the process, the temperature control device 23 calculates the amount of power Q _n supplied to the first heating device 101 and the second heating device 103 from the difference between the detected temperature of the temperature detection device 102 and the target temperature for each frame. the switch control step, calculated in accordance with the supply power amount Q _n, and controls the first switch and the 21 second switch 24 for each segment, high-temperature microwave radiometer according to a first embodiment Compared to temperature control method of Seiminamoto, the amount of power delivered can be further closer to the supply power amount Q _n calculated. As a result, the temperature of the radio wave absorber 62 can be controlled with higher accuracy.

  In each of the above-described embodiments, the storage box heater 64 is provided in the storage box 61. When the storage box heater 64 heats the storage box 61, the radio wave absorber 62 is indirectly heated, and thermal control is performed. Although the panel main body 81 is provided with the thermal control panel heater 82, and the thermal control panel heater 82 heats the thermal control panel main body 81, the configuration in which the radio wave absorber 62 is indirectly heated has been described. 62 may be provided with a radio wave absorber heater, and the radio wave absorber heater may heat the radio wave absorber 62 directly. In this case, a circuit for supplying power to the radio wave absorber temperature sensor so that the temperature of the radio wave absorber 62 becomes a target temperature based on the temperature detected by the radio wave absorber temperature sensor that detects the temperature of the radio wave absorber 62 is provided. A switch for opening and closing is controlled by the temperature control device 23.

  In each of the above embodiments, the first heating device 101 configured from the storage box heater 64 and the thermal control panel heater 82 has been described. However, the first heating apparatus 101 includes either the storage box heater 64 or the thermal control panel heater 82. The first heating device 101 may be used.

  In each of the above embodiments, the temperature detection device 102 detects the temperature of the radio wave absorber 62, and the configuration in which the temperature of the radio wave absorber 62 is controlled so that the detected temperature becomes the target temperature has been described. The detection device 102 may detect the temperature of the storage box 61 and the thermal control panel body 81, and the temperature of the storage box 61 and the thermal control panel body 81 may be controlled so that the detected temperature becomes the target temperature. .

  1 Artificial satellite (base), 2 structures, 3 connecting rods, 4 main reflector, 5 low temperature calibration reflector, 6 high temperature calibration source body, 7 primary radiator, 8 thermal control panel device, 9 rotation center axis, 20 power Supply control device, 21 power supply device, 22 first switch, 23 temperature control device, 24 second switch, 61 storage box, 62 radio wave absorber, 63 radio wave absorber temperature sensor, 64 storage box heater, 65 storage box temperature Sensor, 66 MLI, 81 Thermal control panel body, 82 Thermal control panel heater, 83 Thermal control panel temperature sensor, 84 Spacer, 100 High temperature calibration source, 101 First heating device, 102 Temperature detection device, 103 Second heating device 231 Temperature control program, 611 Top plate, 612 Side plate, 613 Opening.

Claims (2)

A structure provided rotatably with respect to the base;
A main reflector that is fixed to the structure and reflects the observation microwave from the observation object;
A primary radiator that is fixed with respect to the structure and that receives the observation microwave reflected by the main reflector as the structure rotates and moves;
A low-temperature calibration reflector that is fixed to the base, reflects the low-temperature calibration microwave from deep space, and causes the low-temperature calibration microwave to enter the primary radiator at a low-temperature calibration position;
A high-temperature calibration source fixed to the base, radiating high-temperature calibration microwaves, and causing the high-temperature calibration microwaves to enter the primary radiator at a high-temperature calibration position;
The high temperature calibration source is:
A storage box formed with an opening facing the primary radiator at the high temperature calibration position;
A radio wave absorber that is provided inside the containing box and emits the microwave for high-temperature calibration;
A heat insulating material covering the outside of the storage box;
A first heating device that heats the radio wave absorber by being supplied with power;
A first switch for opening and closing a circuit for supplying power to the first heating device;
A temperature detecting device for detecting the temperature of the radio wave absorber;
A temperature control device that controls the first switch based on the temperature detected by the temperature detection device so that the temperature of the radio wave absorber becomes a target temperature;
Measure the temperature of the observation object using the intensity value of the observation microwave received by the primary radiator,
The value of the intensity of the low-temperature calibration microwave received by the primary radiator, the value of the deep space temperature, the value of the intensity of the high-temperature calibration microwave received by the primary radiator, and In the microwave radiometer that calibrates the temperature value of the observation object measured from the intensity value of the observation microwave received by the primary radiator using the detected temperature value of the temperature detection device A temperature control method for a high-temperature calibration source for a microwave radiometer, which is a control method for a high-temperature calibration source,
A power supply amount calculating step of calculating the power supply amount to the first heating device from the difference between the detected temperature and the target temperature every unit time;
The unit time is divided into a plurality of segment times, and a supply power pattern in which the plurality of segment times during which power is supplied to the first heating device is distributed in the unit time is determined according to the amount of power supplied. using the electric power supplied pattern table in response to said amount of power supply, the microwave radiometer for hot calibration source, characterized in that a switch control step of controlling the first switch to each of the segment time Temperature control method. The high temperature calibration source is:
A second heating device that heats the radio wave absorber by being supplied with electric power, and generates a smaller amount of heat than the first heating device;
A second switch for opening and closing a circuit for supplying power to the second heating device;
In the supply power amount calculation step, the supply power amount to the first heating device and the second heating device is calculated for each unit time from the difference between the detected temperature and the target temperature,
2. The temperature control method for a high-temperature calibration source for a microwave radiometer according to claim 1, wherein, in the switch control step, the second switch is controlled for each of the divided times according to the amount of supplied power. .

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