A geosynchronous orbit SAR satellite phase consistency correction compensation system and method

Abstract

The present invention relates to a geosynchronous orbit SAR satellite phase consistency correction and compensation system and method, and in particular to the implementation of geosynchronous orbit SAR satellite phase consistency correction and compensation, and can also be applied to other spacecraft using the method, belonging to the field of SAR imaging technology. The present invention performs phase compensation on the transmitting channel on the +Y deck and the transmitting channel on the -Y deck, and at the same time performs phase compensation on the receiving channel on the +Y deck and the receiving channel on the -Y deck. When imaging is performed under this condition, the degree of deterioration of the imaging sensitivity index is reduced; the present invention performs phase compensation on the transmitting channel on the +Y deck and the transmitting channel on the -Y deck, and at the same time performs phase compensation on the receiving channel on the +Y deck and the receiving channel on the -Y deck. When imaging is performed under this condition, the degree of deterioration of the imaging fuzziness is reduced, which greatly improves the image quality.

Description

Technical Field

[0001] The present invention relates to a system and method for phase consistency correction and compensation of a geosynchronous orbit SAR satellite, and in particular to implementation of phase consistency correction and compensation of a geosynchronous orbit SAR satellite. The system and method can also be applied to other spacecraft using the method, and belong to the technical field of SAR imaging. Background Art

[0002] Geosynchronous SAR satellite (referred to as high-orbit SAR satellite) is a synthetic aperture radar satellite operating in geosynchronous orbit (orbit height of 35786km from the ground). The satellite orbit is high, the imaging mechanism is complex, and the imaging conditions are relatively high, especially the phase consistency requirements between the transmission and reception of multiple channels are relatively stringent. SAR satellite imaging can choose a reflector antenna system or a flat-panel phased array system, but because high-orbit SAR satellites require a larger antenna aperture, the current reflector antenna unit area weight is lighter than the phased array antenna, so the existing high-orbit SAR satellites that have entered engineering are mostly reflector systems. However, the existing high-orbit SAR satellite reflector antenna system payload imaging has the following deficiencies in phase consistency:

[0003] First, if the SAR payload system adopts a reflective surface system, the transmitting channel and the receiving channel are fed by spatial synthesis. Due to the large number of payload equipment and limited satellite layout space, the transmitting channel and the receiving channel need to be arranged on different satellite cabins to meet the thermal control requirements of not concentrating high-power equipment on one cabin.

[0004] Second, in order to meet the requirement that the SAR imaging radar beam must have relative motion with the earth's surface, geosynchronous orbit SAR satellites generally have a certain orbital inclination (in very rare cases, the orbital inclination is zero, but the orbital eccentricity is not zero). At the same time, the SAR payload is required to perform attitude guidance during imaging (that is, the satellite attitude needs to change continuously), which results in a large difference in heat flow outside different panels of the satellite, and ultimately leads to a large temperature difference between multiple payload panels when the SAR payload is working.

[0005] Third, the actual layout and thermal balance test results of the geosynchronous orbit SAR satellite (orbital inclination is 16°) show that the maximum instantaneous temperature difference between the two payload cabin panels in two directions of the satellite (for example, the +Y / -Y cabin panels) can reach 40C°, and the instantaneous temperature difference is constantly changing. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a geosynchronous orbit SAR satellite phase consistency correction and compensation system and method, which can compensate for the phase difference caused by temperature difference in quasi-real time and reduce the decline of SAR image indicators caused by phase difference.

[0007] The technical solution of the present invention is:

[0008] A phase consistency correction and compensation system for a geosynchronous orbit SAR satellite, the correction and compensation system comprising a transmitting channel located on a +Y deck of a geosynchronous orbit SAR satellite, a receiving channel located on a +Y deck of a geosynchronous orbit SAR satellite, a transmitting channel located on a -Y deck of a geosynchronous orbit SAR satellite, a receiving channel located on a -Y deck of a geosynchronous orbit SAR satellite, and a transmitting and receiving common antenna;

[0009] The transmitting channel of the +Y cabin board includes a transmitting phase shifter and a transmitting unit;

[0010] The receiving channel of the +Y deck includes a receiving phase shifter and a receiving unit;

[0011] The transmitting channel of the -Y cabin board includes a transmitting phase shifter and a transmitting unit;

[0012] The receiving channel of the -Y cabin board includes a receiving phase shifter and a receiving unit;

[0013] On the +Y cabin board, the signal emitted by the transmitting signal source first enters the transmitting phase shifter, which shifts the phase of the incoming signal and then enters the transmitting unit. The phase-shifted signal is transmitted by the transmitting unit and then transmitted to the transmitting and receiving common antenna through the transmitting channel. The transmitting and receiving common antenna irradiates the signal to the ground; the transmitting and receiving common antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving unit through the receiving channel. The receiving unit then transmits the scattered echo signal to the receiving phase shifter, and the receiving phase shifter outputs the received signal after phase shifting.

[0014] On the -Y cabin board, the signal emitted by the transmitting signal source first enters the transmitting phase shifter, which shifts the phase of the incoming signal and then enters the transmitting unit. The phase-shifted signal is transmitted by the transmitting unit and then transmitted through the transmitting channel to the transmitting and receiving shared antenna, which irradiates the signal onto the ground; the transmitting and receiving shared antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving unit via the receiving channel. The receiving unit then transmits the scattered echo signal to the receiving phase shifter, which shifts the phase of the received signal and then outputs it.

[0015] Preferably, the method for determining the +Y deck and -Y deck of the geosynchronous orbit SAR satellite is:

[0016] A three-axis coordinate system is established on the satellite body, with the satellite's center of mass as the origin of the coordinate system, the Z axis pointing to the ground, the X axis pointing to the satellite's flight direction, and the Y axis direction is obtained according to the right-hand rule to obtain the +Y deck and -Y deck.

[0017] A method for phase consistency correction and compensation of a geosynchronous orbit SAR satellite, comprising the following steps:

[0018] The first step is to compare the temperatures of the +Y deck and the -Y deck, and then heat the deck with the lower temperature to make the temperature of the deck with the lower temperature close to that of the deck with the higher temperature.

[0019] The second step is to determine the phase values ​​of all transmitting units and all receiving units under different temperature conditions through ground tests, obtain the relationship curve between temperature and phase value and store it on the satellite;

[0020] The third step is to collect the temperatures of all transmitting units and all receiving units on orbit, and obtain the phase value of the transmitting unit or receiving unit collected on orbit according to the relationship curve between temperature and phase value obtained in the second step;

[0021] Step 4: Add the phase values ​​of all the transmitting units on the transmitting channel of the +Y cabin board obtained in the step 3 to obtain the phase value of the transmitting channel of the +Y cabin board;

[0022] The phase values ​​of all the transmitting units on the transmitting channel of the -Y deck obtained in the third step are added together to obtain the phase value of the transmitting channel of the -Y deck;

[0023] The phase values ​​of all the receiving units on the receiving channel of the +Y deck obtained in the third step are added together to obtain the phase value of the receiving channel of the +Y deck;

[0024] The phase values ​​of all the receiving units on the receiving channel of the -Y deck obtained in the third step are added together to obtain the phase value of the receiving channel of the -Y deck;

[0025] Step 5: Subtract the phase value of the transmitting channel of the +Y deck obtained in step 4 from the phase value of the transmitting channel of the -Y deck to obtain a transmitting channel compensation value;

[0026] Step 6: Subtract the phase value of the receiving channel of the +Y deck obtained in step 4 from the phase value of the receiving channel of the -Y deck to obtain a receiving channel compensation value;

[0027] In the seventh step, the transmitting phase shifter performs phase compensation on the signal transmitted by the transmitting signal source according to the transmitting channel compensation value obtained in the fifth step, and the receiving phase shifter performs phase compensation on the received signal according to the receiving channel compensation value obtained in the sixth step;

[0028] In the eighth step, after the phase compensation of the transmitting channel and the receiving channel, SAR starts to image the ground to obtain an image with better image indicators.

[0029] Preferably, in the first step, the cabin plate with a lower temperature is heated by thermal control heating.

[0030] Preferably, in the first step, a method for determining that the temperature of the lower temperature deck is close to the temperature of the higher temperature deck is:

[0031] In the process of heating the lower temperature deck, as the temperature of the lower temperature deck increases, the temperature of the higher temperature deck will also increase. When the heating rate of the lower temperature deck is not greater than the heating rate of the higher temperature deck, the heating of the lower temperature deck is stopped. At this time, the temperature of the +Y deck is T1, the temperature of the -Y deck is T2, and the temperature difference T0 between the +Y deck and the -Y deck is the absolute value of the difference between T1 and T2. T0 is greater than 0. At this time, it is considered that the temperature of the lower temperature deck is close to that of the higher temperature deck.

[0032] Preferably, in the second step, the temperature selected when determining the phase values ​​of all transmitting units and all receiving units under different temperature conditions through ground tests is: from -35°C to 70°C, and a phase value is determined every 5°C.

[0033] Preferably, after the SAR starts imaging the ground in the eighth step, the first to seventh steps are repeated before the next imaging, and imaging is performed after phase compensation is completed.

[0034] Beneficial Effects

[0035] The method of the present invention can bring the following benefits:

[0036] (1) The present invention performs phase compensation on the transmitting channel on the +Y deck and the transmitting channel on the -Y deck, and simultaneously performs phase compensation on the receiving channel on the +Y deck and the receiving channel on the -Y deck. Under such conditions, the imaging sensitivity index deterioration is reduced (before compensation, the system sensitivity deteriorates by 2.56 dB at a temperature difference of 40°C, and after compensation, the system sensitivity deteriorates by only 0.50 dB at a temperature difference of 5°C; theoretically, after compensation, the system sensitivity will no longer deteriorate at a temperature difference of 0°C).

[0037] (2) The present invention performs phase compensation on the transmitting channel on the +Y deck and the transmitting channel on the -Y deck, and simultaneously performs phase compensation on the receiving channel on the +Y deck and the receiving channel on the -Y deck. Under such conditions, when imaging is performed, the degree of deterioration of imaging blur is reduced, thereby greatly improving the image quality (before compensation, the image blur deteriorates by 3.93 dB at a temperature difference of 40°C, and only deteriorates by 0.80 dB at a temperature difference of 5°C after compensation; theoretically, after compensation, the image blur no longer deteriorates at a temperature difference of 0°C). BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0039] Figure 2A schematic diagram of the system composition of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] A geosynchronous orbit SAR satellite phase consistency correction and compensation system, the correction and compensation system comprising a transmitting phase shifter, a receiving phase shifter, a transmitting unit, and a receiving unit;

[0042] A three-axis coordinate system is established on the satellite body, with the satellite's center of mass as the origin of the coordinate system, the Z axis pointing to the ground, the X axis pointing to the satellite's flight direction, and the Y axis direction obtained according to the right-hand rule;

[0043] The +Y cabin of the geosynchronous orbit SAR satellite is provided with a transmitting unit and a receiving unit;

[0044] The -Y cabin of the geosynchronous orbit SAR satellite is provided with a transmitting unit and a receiving unit;

[0045] The signal transmitted by the transmitting signal source first enters the transmitting phase shifter, which shifts the phase of the incoming signal and then enters the transmitting unit. The signal transmitted by the transmitting signal source is transmitted by the transmitting unit and then transmitted to the transmitting and receiving common antenna through the transmitting channel. The transmitting and receiving common antenna irradiates the signal transmitted by the transmitting signal source onto the ground.

[0046] The transmitting and receiving shared antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving unit through the receiving channel. The receiving unit then transmits the scattered echo signal to the receiving phase shifter, and the receiving phase shifter outputs the received signal after phase shifting.

[0047] A geosynchronous orbit SAR satellite phase consistency correction and compensation method, the method steps comprising:

[0048] The first step is to compare the temperatures of the +Y deck and the -Y deck, and then heat the deck with the lower temperature by means of thermal control heating. In the process of heating the deck with the lower temperature, as the temperature of the deck with the lower temperature increases, the temperature of the deck with the higher temperature will also increase. When the heating rate of the deck with the lower temperature is not greater than the heating rate of the deck with the higher temperature, the heating of the deck with the lower temperature is stopped. At this time, the temperature of the +Y deck is T1, the temperature of the -Y deck is T2, and the temperature difference T0 between the +Y deck and the -Y deck is the absolute value of the difference between T1 and T2, and T0 is greater than 0.

[0049] The second step is to determine the phase values ​​of all transmitting units and all receiving units under different temperature conditions through ground tests and store them on the satellite; different temperature conditions refer to temperatures ranging from -35°C to 70°C, with a phase value determined every 5°C to obtain a relationship curve between temperature and phase value;

[0050] The third step is to collect the temperatures of all transmitting units and all receiving units on orbit, and obtain the phase value of the transmitting unit or receiving unit collected on orbit according to the relationship curve between temperature and phase value obtained in the second step;

[0051] The fourth step is to add the phase values ​​of all the transmitting units on the transmitting channel obtained in the third step to obtain the phase value of the transmitting channel, and to add the phase values ​​of all the receiving units on the receiving channel to obtain the phase value of the receiving channel;

[0052] Step 5: Subtract the phase value of the transmitting channel on the +Y deck obtained in step 4 from the phase value of the transmitting channel on the -Y deck to obtain a transmitting channel compensation value;

[0053] Step 6: Subtract the phase value of the receiving channel on the +Y deck obtained in step 4 from the phase value of the receiving channel on the -Y deck to obtain a receiving channel compensation value;

[0054] In the seventh step, the transmitting phase shifter performs phase compensation on the signal transmitted by the transmitting signal source according to the transmitting channel compensation value obtained in the fifth step, and the receiving phase shifter performs phase compensation on the received signal according to the receiving channel compensation value obtained in the sixth step;

[0055] In the eighth step, SAR starts imaging the ground. After the imaging is completed, steps one to seven are repeated before the next imaging, and imaging is performed again after phase compensation is completed.

[0056] The phase difference between the transmitting channel and the receiving channel caused by the temperature difference will lead to a serious decline in imaging indicators (imaging sensitivity, imaging ambiguity, etc.). The following table is a table of image indicator deterioration under different temperature difference conditions for a certain model of geosynchronous SAR satellite.

[0057] Table 1 Image index deterioration under different temperature difference conditions

[0058] Temperature difference of cabin 0℃ 5℃ 10℃ 20℃ 30℃ 40℃ System sensitivity deterioration-dB 0 0.50 0.95 1.49 2.1 2.56 Image blur degradation - dB 0 0.80 1.45 2.42 3.63 3.93

[0059] Example

[0060] A phase consistency correction and compensation system for geosynchronous orbit SAR satellites, such as Figure 2 As shown, the correction and compensation system includes transmitting phase shifter 1, transmitting phase shifter 1, receiving phase shifter 1, receiving phase shifter 2, transmitting unit 1, transmitting unit 2, transmitting unit 3, transmitting unit 4, transmitting unit 5, transmitting unit 6, receiving unit 1, receiving unit 2, receiving unit 3, receiving unit 4, receiving unit 5, and receiving unit 6.

[0061] A three-axis coordinate system is established on the satellite body, with the satellite's center of mass as the origin of the coordinate system, the Z axis pointing to the ground, the X axis pointing to the satellite's flight direction, and the Y axis direction obtained according to the right-hand rule.

[0062] The +Y cabin board of the geosynchronous orbit SAR satellite is provided with a transmitting unit 1, a transmitting unit 2, a transmitting unit 3 and a receiving unit 1, a receiving unit 2, and a receiving unit 3.

[0063] The -Y cabin board of the geosynchronous orbit SAR satellite is provided with a transmitting unit 4, a transmitting unit 5, a transmitting unit 6 and a receiving unit 4, a receiving unit 5, a receiving unit 6.

[0064] That is, the transmitting channel 1 (transmitting units 1 to 3 and their connecting cables) and the receiving channel 1 (receiving units 1 to 3 and their connecting cables) are arranged on the +Y direction cabin board; the transmitting channel 2 (transmitting units 4 to 6 and their connecting cables) and the receiving channel 2 (receiving units 4 to 6 and their connecting cables) are arranged on the -Y direction cabin board;

[0065] The signal transmitted by the transmitting signal source 1 first enters the transmitting phase shifter 1, which shifts the phase of the incoming signal and then transmits it to the transmitting and receiving common antenna through the transmitting channel 1. The transmitting and receiving common antenna irradiates the signal transmitted by the transmitting signal source 1 onto the ground;

[0066] The transmitting and receiving common antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving phase shifter 1 via the receiving channel 1. The receiving phase shifter 1 shifts the phase of the received signal and then outputs it.

[0067] The signal transmitted by the transmitting signal source 2 first enters the transmitting phase shifter 2, which shifts the phase of the incoming signal and then transmits it to the transmitting and receiving shared antenna through the transmitting channel 2. The transmitting and receiving shared antenna irradiates the signal transmitted by the transmitting signal source 2 onto the ground;

[0068] The transmitting and receiving common antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving phase shifter 2 via the receiving channel 2. The receiving phase shifter 2 shifts the phase of the received signal and then outputs it.

[0069] A phase consistency correction compensation method for geosynchronous orbit SAR satellites, such as Figure 1 As shown, the method steps include:

[0070] In the first step, the temperatures of the +Y cabin board and the -Y cabin board are collected. The temperature of the +Y cabin board is 40°C and the temperature of the -Y cabin board is 0°C. The -Y cabin board is added by thermal control heating. When the temperature of the -Y cabin board is heated to 30°C, the temperature of the +Y cabin board rises to 45°C. At this time, the heating rate of the -Y cabin board is lower than that of the +Y cabin board, and the heating of the -Y cabin board is stopped.

[0071] The second step is to determine the phase values ​​of the transmitting unit 1-6 and the receiving unit 1-6 under different temperature conditions through ground tests and store them on the satellite;

[0072] The temperature ranges from -35°C to 70°C in steps of 5°C: T = Tn = [-35 -30 -25 -20 -15-10 -5 0 5 10 15 20 25 30 40 45 50 55 60 65 70] (°C), n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, a total of 21 temperature values;

[0073] According to the experimental measurements, the phase values ​​of the transmitters 1-6 at different temperatures are obtained, and the temperature-phase value curves of the transmitters 1-6 are obtained by curve fitting based on the obtained phase values. TX11 (T),φ TX12 (T),φ TX13 (T),φ TX24 (T),φ TX25 (T),φ TX26 (T);

[0074] According to the experimental measurements, the phase values ​​of the receiving units 1-6 at different temperatures are obtained, and the temperature-phase value curves of the receiving units 1-6 are obtained by curve fitting based on the obtained phase values. RX11 (T),φ RX12 (T),φ RX13 (T),φ RX24 (T),φ RX25 (T),φ RX26 (T);

[0075] In the third step, the temperatures of the transmitting units 1-6 and the receiving units 1-6 collected on-orbit were 50°C, 52°C, 51°C, 35°C, 37°C, 36°C, 45°C, 47°C, 46°C, 30°C, 32°C, and 31°C respectively;

[0076] According to the relationship curve between temperature and phase value obtained in the second step, the phase values ​​of the transmitters 1-6 and the receivers 1-6 are as follows: 20°, 21°, 20.5°, 13°, 14°, 13.5°, 15°, 16°, 15.5°, 8°, 9°, 8.5°:

[0077] The fourth step is to add the phase values ​​of all the transmitting units on the transmitting channel obtained in the third step to obtain the phase value of the transmitting channel, and add the phase values ​​of all the receiving units on the receiving channel to obtain the phase value of the receiving channel; the phase value of the transmitting channel on the +Y deck is 20°+21°+20.5°=61.5°; the phase value of the transmitting channel on the -Y deck is 13°+14°+13.5°=40.5°; the phase value of the receiving channel on the +Y deck is 15°+16°+15.5°=46.5°; the phase value of the receiving channel on the -Y deck is 8°+9°+8.5°=25.5°;

[0078] Step 5: Subtract the phase value of the transmitting channel on the +Y board obtained in step 4 from the phase value of the transmitting channel on the -Y board to obtain a transmitting channel compensation value; the transmitting channel compensation is 61.5°-40.5°=21°;

[0079] Step 6: Subtract the phase value of the receiving channel on the +Y board obtained in step 4 from the phase value of the receiving channel on the -Y board to obtain a receiving channel compensation value; receiving channel compensation 46.5°-25.5°=21°

[0080] In the seventh step, without loss of generality, it can be assumed that the initial phase shifts of the transmitting phase shifters 1, 2 and the receiving phase shifters 1, 2 are all 0°; the transmitting phase shifter performs phase compensation on the signal transmitted by the transmitting signal source according to the transmitting channel compensation value obtained in the fifth step (the phase value of the transmitting phase shifter 2 can be set to 21°); the receiving phase shifter performs phase compensation on the received signal according to the receiving channel compensation value obtained in the sixth step (the phase value of the receiving phase shifter 2 can be set to 21°), and the phase consistency correction compensation of the geosynchronous orbit SAR satellite is completed;

[0081] In the eighth step, SAR starts to image the ground and obtain an image. After the imaging is completed, steps one to seven are repeated before the next imaging, and imaging is performed again after phase compensation is completed.

[0082] According to the data in Table 1, the phase error caused by the initial 40°C temperature difference can improve the image quality degradation through phase correction compensation (the system sensitivity deteriorates from 2.5dB to no deterioration in theory; the image blur deteriorates from 3.93dB to no deterioration in theory).

Claims

1. A geosynchronous orbit SAR satellite phase consistency correction and compensation system, characterized by: The correction and compensation system includes a transmitting channel located on the +Y deck of a geosynchronous orbit SAR satellite, a receiving channel located on the +Y deck of a geosynchronous orbit SAR satellite, a transmitting channel located on the -Y deck of a geosynchronous orbit SAR satellite, a receiving channel located on the -Y deck of a geosynchronous orbit SAR satellite, and a transmitting and receiving common antenna; The transmitting channel of the +Y cabin board includes a transmitting phase shifter and a transmitting unit; The receiving channel of the +Y deck includes a receiving phase shifter and a receiving unit; The transmitting channel of the -Y cabin board includes a transmitting phase shifter and a transmitting unit; The receiving channel of the -Y cabin board includes a receiving phase shifter and a receiving unit; On the +Y cabin board, the signal emitted by the transmitting signal source first enters the transmitting phase shifter, which shifts the phase of the incoming signal and then enters the transmitting unit. The phase-shifted signal is transmitted by the transmitting unit and then transmitted to the transmitting and receiving common antenna through the transmitting channel. The transmitting and receiving common antenna irradiates the signal to the ground; the transmitting and receiving common antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving unit through the receiving channel. The receiving unit then transmits the scattered echo signal to the receiving phase shifter, and the receiving phase shifter outputs the received signal after phase shifting. On the -Y cabin board, the signal emitted by the transmitting signal source first enters the transmitting phase shifter, which shifts the phase of the incoming signal and then enters the transmitting unit. The phase-shifted signal is transmitted by the transmitting unit and then transmitted through the transmitting channel to the transmitting and receiving shared antenna, which irradiates the signal onto the ground; the transmitting and receiving shared antenna receives the scattered echo of the ground signal, and the scattered echo signal is transmitted to the receiving unit via the receiving channel. The receiving unit then transmits the scattered echo signal to the receiving phase shifter, which shifts the phase of the received signal and then outputs it.

2. A geosynchronous orbit SAR satellite phase consistency correction and compensation system according to claim 1, characterized in that: The method for determining the +Y deck and -Y deck of the geosynchronous orbit SAR satellite is as follows: A three-axis coordinate system is established on the satellite body, with the satellite's center of mass as the origin of the coordinate system, the Z axis pointing to the ground, the X axis pointing to the satellite's flight direction, and the Y axis direction is obtained according to the right-hand rule to obtain the +Y deck and -Y deck.

3. A method for phase consistency correction and compensation of a geosynchronous orbit SAR satellite using the system described in claim 1 or 2, characterized in that the steps include: The first step is to compare the temperatures of the +Y deck and the -Y deck, and then heat the deck with the lower temperature to make the temperature of the deck with the lower temperature close to that of the deck with the higher temperature. The second step is to determine the phase values ​​of all transmitting units and all receiving units under different temperature conditions through ground tests, obtain the relationship curve between temperature and phase value and store it on the satellite; The third step is to collect the temperatures of all transmitting units and all receiving units on orbit, and obtain the phase value of the transmitting unit or receiving unit collected on orbit according to the relationship curve between temperature and phase value obtained in the second step; Step 4: Add the phase values ​​of all the transmitting units on the transmitting channel of the +Y cabin board obtained in the step 3 to obtain the phase value of the transmitting channel of the +Y cabin board; The phase values ​​of all the transmitting units on the transmitting channel of the -Y deck obtained in the third step are added together to obtain the phase value of the transmitting channel of the -Y deck; The phase values ​​of all the receiving units on the receiving channel of the +Y deck obtained in the third step are added together to obtain the phase value of the receiving channel of the +Y deck; The phase values ​​of all the receiving units on the receiving channel of the -Y deck obtained in the third step are added together to obtain the phase value of the receiving channel of the -Y deck; Step 5: Subtract the phase value of the transmitting channel of the +Y deck obtained in the fourth step from the phase value of the transmitting channel of the -Y deck to obtain a transmitting channel compensation value; Subtract the phase value of the receiving channel of the +Y deck obtained in the fourth step from the phase value of the receiving channel of the -Y deck to obtain a receiving channel compensation value; In the sixth step, the transmitting phase shifter performs phase compensation on the signal transmitted by the transmitting signal source according to the transmitting channel compensation value obtained in the fifth step, and the receiving phase shifter performs phase compensation on the received signal according to the receiving channel compensation value obtained in the fifth step.

4. The method for phase consistency correction and compensation of geosynchronous orbit SAR satellite according to claim 3, characterized in that: In the first step, the cabin plate with a lower temperature is heated by thermal control heating.

5. The method for phase consistency correction and compensation of geosynchronous orbit SAR satellite according to claim 3 or 4, characterized in that: In the first step, the method for determining whether the temperature of the lower temperature deck is close to the temperature of the higher temperature deck is as follows: In the process of heating the lower temperature panel, as the temperature of the lower temperature panel increases, the temperature of the higher temperature panel will also increase. When the heating rate of the lower temperature panel is not greater than the heating rate of the higher temperature panel, the heating of the lower temperature panel is stopped. At this time, the temperature of the +Y panel is T1, the temperature of the -Y panel is T2, and the temperature difference T0 between the +Y panel and the -Y panel is the absolute value of the difference between T1 and T2. T0 is greater than 0. At this time, it is considered that the temperature of the lower temperature panel is close to that of the higher temperature panel.

6. The phase consistency correction and compensation method for geosynchronous orbit SAR satellite according to claim 3 or 4, characterized in that: In the second step, the temperature selected when determining the phase values ​​of all transmitting units and all receiving units under different temperature conditions through ground tests is: from -35°C to 70°C, and a phase value is determined every 5°C.

7. The phase consistency correction and compensation method for geosynchronous orbit SAR satellite according to claim 3 or 4, characterized in that: After completing the phase compensation of the transmitting channel and the receiving channel, SAR starts to image the ground and obtain images with better image indicators.

8. The method for phase consistency correction and compensation of geosynchronous orbit SAR satellite according to claim 7, characterized in that: After SAR starts imaging the ground, steps one to seven are repeated before the next imaging, and imaging is performed after phase compensation is completed.

Images