CN115963460A - Phase error compensation method and system between light and small satellite SAR antenna boards - Google Patents
Phase error compensation method and system between light and small satellite SAR antenna boards Download PDFInfo
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Abstract
The invention provides a method and a system for compensating phase errors between light small-sized satellite SAR antenna boards, which comprises the following steps: step S1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state; step S2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data; and step S3: carrying out space distance calibration on the data after data processing and analysis; and step S4: and calculating the phase error between the plates according to the calibrated space distance. The phase error compensation method between the plates of the light and small satellite SAR antenna mainly solves the problem of phase error between the plates caused by the fact that the SAR antenna sub-plates are installed on a satellite cabin body and cables between the plates are reconnected, and the phase error of each channel between the plates is not required to be measured by a near-field scanning system of a microwave darkroom.
Description
Technical Field
The invention relates to the technical field of aerospace systems, in particular to a method and a system for compensating phase errors between light and small satellite SAR antenna boards.
Background
A satellite-borne Synthetic Aperture Radar (SAR) is an all-weather all-day active earth observation means, and plays an important application value in the fields of military high-resolution observation, natural resource monitoring, ocean monitoring and the like. The planar active phased array system antenna adopted by most satellite-borne SAR satellites is structurally composed of a plurality of sub-boards due to the envelope limitation of a carrier rocket, and the SAR antenna is folded and unfolded in the whole satellite testing stage.
The traditional large satellite SAR central electronic equipment and antenna integration test are connected with the whole satellite cabin, so that the occupied whole satellite cabin seriously delays the satellite mounting test time of the platform. For a light small SAR satellite, in order to shorten the development process of the whole satellite, the SAR load product integration test stage can be free from being integrated with a satellite cabin, but the SAR antenna is subjected to inter-board high-frequency cable disassembly and the processes of sub-board transportation, installation, cabin integration and the like in the rotation stage, so that the phase errors between boards can be caused by the fact that antenna sub-boards are installed on the satellite cabin and cables between boards are reconnected, the errors between boards mainly come from main path radio frequency path errors and scaling network errors, and the main radio frequency path errors can influence the load imaging quality. Therefore, the phase error of the cable between the antenna boards must be calibrated and compensated accurately, so as to ensure the phase consistency of all radiation channels of the SAR antenna full array.
For a traditional SAR satellite, an inner calibrator is usually adopted to monitor the relative changes of the amplitude and phase of each active channel of a system in the imaging process, and compensation and calibration are carried out simultaneously, but the conventional wired inner calibration method cannot distinguish whether the phase error between plates comes from a main path or a calibration path; the vector network analyzer is adopted to measure the phase between the measurement boards, cables between the boards need to be disconnected, one end of the vector network is connected with the cables between the boards, and the other end of the vector network is connected with the total power divider, the method does not need to electrify the whole satellite, the method is simple, but when the cables between the boards are restored to the on-satellite state, the shape of the connection position of the cables cannot be avoided to be changed, so that the phase error compensation between the boards is not accurate enough, and meanwhile, the method relates to the operation of cables on the satellite, and the risk is high; a microwave darkroom near-field scanning system is adopted to carry out amplitude and phase monitoring on each T/R channel between the plates, the method is high in measurement accuracy, but the method is complex in operation and high in time consumption, and the development cycle of the light and small satellite can be prolonged.
Through retrieval, although a plurality of invention patents exist in China in the research of phase error compensation methods among light and small satellite SAR antenna boards, the method is essentially different from the realization of the invention, and the specific conditions are as follows:
the invention relates to a method for measuring and compensating amplitude and phase errors among channels of a multi-channel satellite-borne SAR antenna (2022, patent application No. 202210139383.5), which adopts a plane near-field test system to measure the amplitude and phase data of a radiation unit corresponding to each T/R component of a receiving and transmitting feeder link of the SAR antenna, and does not consider the consistency of the amplitude and phase errors of the channels among adjacent sub-plates;
the invention discloses a multi-channel SAR antenna performance detection method based on wireless single T/R calibration (2019, patent application number 201911150553.4), which is used for detecting the performance of an SAR antenna by adopting a wireless internal calibration method, mainly detects the relative variation of the SAR antenna performance before and after a vibration test, and does not introduce the measurement and compensation of inter-plate channel phase errors;
the invention relates to a device for checking the amplitude phase of a T/R channel of a satellite SAR antenna and an operation method thereof (2019, application number 201910689477.8), mainly introduces the operation of a measuring device, and does not propose the measurement and compensation of the phase error of a channel between plates;
the invention mainly detects the relative variation of the amplitude and phase between channels under different working conditions, and does not mention the measurement and compensation of the phase error of the channel between plates; a novel satellite-borne SAR wireless internal calibration method research (2018, reported in the radar), the article provides that a wireless internal calibration method obtains the amplitude-phase characteristics of a T/R channel, and does not mention the measurement and compensation of the phase error of the channel between plates;
according to the method for measuring the phase difference between the whole satellite phases of the patent satellite-borne synthetic aperture radar in the far field (2019, application number 201910291110.0), a data model established by the method is not accurate enough, certain approximate errors exist, and in addition, the method for compensating the phase between the plates is not provided.
Aiming at the phase compensation method of the channels between the small and light satellite SAR antenna boards, no description or report similar to the technology of the invention is found at present, and similar data at home and abroad is not collected.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a phase error compensation method and a phase error compensation system between light and small satellite SAR antenna boards.
The phase error compensation method between the light small-sized satellite SAR antenna boards provided by the invention comprises the following steps:
step S1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
step S2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
and step S3: carrying out spatial distance calibration on the data after data processing and analysis;
and step S4: and calculating the phase error between the plates according to the calibrated space distance.
Preferably, in the step S1:
aiming the horn antenna probe and the SAR antenna array surface by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array surface and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relation between the laser range finder and the horn probe, and calculating the specific position relation between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, coupling to each T/R assembly receiving channel of an active phased array antenna through space, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R assembly, the transmitting power of the probe is taken from the receiving output signal of the internal calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm, the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r The receiving dynamic state of the T/R component is met;
the receiving scaling signal chain comprises an internal scaling module output power P cal Scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver manual gain control M re Calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
p series connection in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
Preferably, in the step S2:
the load imaging mode is set as a continuous testing calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission while recording and simultaneously placing; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and (3) carrying out pulse pressure processing on the load data on the ground, and extracting phase values of peak points of all the T/R channels.
Preferably, in the step S3:
and inverting the space distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, wherein the method comprises the following steps:
step S3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance from the phase center of the horn antenna to the antenna array surface;
step S3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n For each daughter board channel n phase, k is constant
Preferably, in the step S4:
step S4.1: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are respectively calculated;
step S4.2: after compensating the phase error of each channel of the daughter board, calculating the R of each daughter board by adopting a function fitting mode 0 And a constant c;
step S4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y on two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
step S4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
The invention provides a phase error compensation system between light small-sized satellite SAR antenna boards, which comprises:
a module M1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
a module M2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
a module M3: carrying out space distance calibration on the data after data processing and analysis;
a module M4: and calculating the phase error between the plates according to the calibrated space distance.
Preferably, in said module M1:
aiming the horn antenna probe and the SAR antenna array plane by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array plane and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relationship between the laser range finder and the horn probe, and calculating the specific position relationship between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, receiving channels of all T/R components of an active phased array antenna through spatial coupling, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R component, the transmitting power of the probe is taken from the receiving output signal of the inner calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm and the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r The receiving dynamic state of the T/R component is met;
the receiving scaling signal chain comprises an internal scaling module output power P cal Scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna reception gain G r Microwave combined insertion loss M L Gain G of receiver re Receiver manual gain control M re And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
series connection P in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
Preferably, in said module M2:
the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission and recording and simultaneous discharging; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
Preferably, in said module M3:
and inverting the space distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, wherein the method comprises the following steps:
module M3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance between the phase center of the horn antenna and the antenna array surface;
module M3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n For each daughter board channel n phase, k is constant
Preferably, in said module M4:
module M4.1: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are respectively calculated;
module M4.2: after compensating the phase error of each channel of the daughter board, calculating the R of each daughter board by adopting a function fitting mode 0 And a constant c;
module M4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y on two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
module M4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
Compared with the prior art, the invention has the following beneficial effects:
1. the phase error compensation method between the SAR antenna boards of the light and small SAR satellite mainly solves the problem of phase error between boards caused by the fact that the SAR antenna sub-boards are installed on a satellite cabin body and cables between the boards are reconnected, and the phase error of each channel between the boards is not required to be measured by a near-field scanning system of a microwave darkroom;
2. the phase error compensation method between the SAR antenna boards of the light and small SAR satellite is simple to operate, the precision is guaranteed, the development period of the small satellite is obviously shortened, the whole satellite testing efficiency is improved, an important technical guarantee is provided for the mass production of the light and small satellite, and the development progress of the mass small satellite is accelerated;
3. the phase error compensation method between the light small SAR satellite SAR antenna boards makes up the defect that an internal calibration system cannot monitor a semi-steel cable and a waveguide which are connected with a T/R component and a waveguide subarray, and can also monitor the amplitude-phase change condition caused by the whole link of each T/R channel of the SAR antenna daughter board along with the whole satellite integration test process (transition and mechanical vibration);
4. the phase error compensation method between the SAR satellite antenna boards of the light and small SAR satellite is also suitable for phase error compensation between all the SAR satellite boards adopting the planar active phased array antenna.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic flow diagram of the process of the present invention;
FIG. 2 is a top view of the SAR antenna layout of the method of the present invention;
FIG. 3 is a front view of the SAR antenna array layout of the method of the present invention;
FIG. 4 is a schematic diagram of the spherical wave principle of the antenna according to the method of the present invention;
FIG. 5 is a graph showing the phase error distribution between the front plates compensated by the method of the present invention;
FIG. 6 is a graph of the phase error distribution between the compensated back plates according to the method of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
Example 1:
the invention discloses a phase error compensation method between light and small satellite SAR antenna boards, and belongs to the technical field of aerospace systems. The method mainly comprises the following steps: step 1, accurately calibrating the position of a horn antenna; step 2, calculating the level of the radio frequency link; step 3, establishing a wireless internal setting test state; step 4, setting a radar load working parameter instruction packet mode and parameters, starting up the load for imaging, and processing and analyzing data; step 5, accurately calibrating the spatial distance according to the phase data; and 6, compensating and verifying the phase error between the plates. According to the phase error compensation method between the light and small-sized satellite SAR antenna boards, simple and efficient testing is achieved through the standard horn antenna, complex testing operation of a traditional darkroom plane near-field scanning system is not needed, time consumption is greatly reduced, precision is guaranteed, the development period of the light and small-sized SAR satellite is obviously shortened, the whole satellite testing efficiency is improved, and important technical guarantee is provided for batch production of the light and small-sized satellite.
As shown in fig. 1 to 6, the method for compensating phase errors between the light small-sized satellite SAR antenna boards provided by the present invention includes:
step S1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
specifically, in the step S1:
aiming the horn antenna probe and the SAR antenna array plane by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array plane and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relationship between the laser range finder and the horn probe, and calculating the specific position relationship between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, receiving channels of all T/R components of an active phased array antenna through spatial coupling, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R assembly, the transmitting power of the probe is taken from the receiving output signal of the internal calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm, the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r Satisfy T/R groupA piece receiving dynamic state;
the receiving scaling signal chain comprises an internal scaling module output power P cal Scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver manual gain control M re And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
series connection P in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
Step S2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
specifically, in the step S2:
the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission and recording and simultaneous discharging; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
And step S3: carrying out spatial distance calibration on the data after data processing and analysis;
specifically, in the step S3:
and inverting the space distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, wherein the method comprises the following steps:
step S3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance between the phase center of the horn antenna and the antenna array surface;
step S3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n For each daughter board channel n phase, k is constant
And step S4: and calculating the phase error between the plates according to the calibrated space distance.
Specifically, in the step S4:
step S4.1: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are respectively calculated;
step S4.2: after the phase errors of the channels of the daughter boards are compensated, the R of each daughter board is calculated by adopting a function fitting mode 0 And a constant c;
step S4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
step S4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
Example 2:
example 2 is a preferred example of example 1, and the present invention will be described in more detail.
The invention also provides a phase error compensation system between the light small-sized satellite SAR antenna boards, which can be realized by executing the flow steps of the phase error compensation method between the light small-sized satellite SAR antenna boards, namely, the phase error compensation method between the light small-sized satellite SAR antenna boards can be understood as the preferred implementation mode of the phase error compensation system between the light small-sized satellite SAR antenna boards by the technical personnel in the field.
The invention provides a phase error compensation system between light small-sized satellite SAR antenna boards, which comprises:
a module M1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
specifically, in the module M1:
aiming the horn antenna probe and the SAR antenna array surface by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array surface and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relationship between the laser range finder and the horn probe, and calculating the specific position relationship between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, coupling to each T/R assembly receiving channel of an active phased array antenna through space, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R assembly, the transmitting power of the probe is taken from the receiving output signal of the internal calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm, the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r The receiving dynamic state of the T/R component is met;
the receiving scaling signal chain comprises an internal scaling module output power P cal And scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver manual gain control M re And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
series connection P in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
A module M2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
in particular, in said module M2:
the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission and recording and simultaneous discharging; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
A module M3: carrying out space distance calibration on the data after data processing and analysis;
in particular, in said module M3:
and inverting the space distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, wherein the method comprises the following steps:
module M3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance from the phase center of the horn antenna to the antenna array surface;
module M3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n K is constant for each phase of the daughter board channel n
A module M4: and calculating the phase error between the plates according to the calibrated space distance.
Specifically, in the module M4:
module M4.1: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are respectively calculated;
module M4.2: after the phase errors of the channels of the daughter boards are compensated, the R of each daughter board is calculated by adopting a function fitting mode 0 And a constant c;
module M4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
module M4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
Example 3:
example 3 is a preferred example of example 1, and the present invention will be described in more detail.
The method comprises the steps of disconnecting the internal calibration system from an antenna calibration network port, connecting a fixed attenuator with a horn probe through a ground high-frequency test cable with a certain length to form a wireless external calibration network, forming a transceiving loop with the SAR antenna, and establishing a wireless internal calibration state. Obtaining main path phase data of each single T/R channel between sub-boards by adopting a wireless internal calibration method, and accurately calibrating the R of each sub-board by adopting a function fitting mode based on the obtained phase data of each sub-board channel 0 And a constant c; r is to be 0 Substituting the sum constant c into a spherical wave equation, respectively fitting two curves between the phases and Y at two sides of each plate, and then calculating the phases of the two curves at the middle point, wherein the phase difference is the phase difference between adjacent plates; between the daughter boardsAfter the phase error of the channel is compensated, the R of each daughter board is accurately calibrated again by adopting a function fitting mode 0 And a constant c; r is to be 0 Substituting the sum constant c into a spherical wave equation, and calculating the compensated phase difference between the plates; and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
The invention adopts a wireless internal calibration mode to realize the phase compensation among the SAR antenna boards, and can monitor the phase error among the boards only through a radio frequency transceiving path without an antenna calibration network, thereby carrying out the phase error compensation among the boards. The method does not need to carry out complicated test operation of the traditional darkroom plane near-field scanning system, greatly reduces time consumption, ensures the precision, obviously shortens the development period of the light small SAR satellite, improves the whole satellite test efficiency, and provides important technical support for the mass production of the light small SAR satellite. In addition, the invention makes up the defect that the internal calibration system can not monitor the semi-steel cable and the waveguide connected with the T/R component and the waveguide subarray through a wireless internal calibration testing method, and can monitor the amplitude-phase change condition caused by the full link of each T/R channel of the SAR antenna daughter board along with the whole satellite integration testing process (transition and mechanical vibration).
In order to achieve the above object, the present invention is achieved by the following technical solutions.
Referring to fig. 1, fig. 1 is a block flow diagram of a phase error compensation method between antenna plates of a light and small SAR satellite according to this embodiment, and the specific process steps are as follows:
a phase error compensation method between light small satellite SAR antenna boards comprises the following steps:
step 2, calculating the level of the radio frequency link;
step 3, establishing a wireless internal setting test state;
step 4, setting a radar load working parameter instruction packet mode and parameters, starting up the load for imaging, and processing and analyzing data;
and 6, compensating and verifying the phase error between the plates.
Wherein step 1 is the preparation of the whole pre-test site.
Step 2 is the calculation of the level of the whole radio frequency link, which is equal to the evaluation of the system level.
And step 3, establishing the whole test state, including the connection of the ground cable and the satellite cable.
And step 4, setting an instruction packet at the beginning of the test, starting up the load for imaging, and processing and analyzing data.
And 5, calibrating the space distance according to the data processed in the step 4.
And 6, calculating and compensating and verifying the phase error between the plates according to the space distance calibrated in the step 5.
Preferably, in the step 1, a level is adopted to accurately aim at the horn antenna probe and the SAR antenna array surface, so that the horn antenna probe is ensured to be parallel to the SAR antenna array surface, and the horn antenna probe is ensured to be vertical to the ground; and fixing the laser range finder on the horn antenna probe, and measuring the relative position relationship between the laser range finder and the horn probe so as to calculate the specific position relationship between the horn probe and the SAR antenna array surface. The invention ensures that the radiation pattern of each unit of the horn antenna and the SAR antenna is in the main lobe of the wave beam; the distance between the horn probe and each unit of the SAR antenna is ensured to meet the far field condition; the phase measurement between the plates is carried out by ensuring that the horn antenna is aligned with the mechanical center between the sub-plates of the SAR antenna array surface.
Preferably, in step 2, the method uses a receiving scaling signal link, and the output signal of the frequency modulation signal source is transmitted to the horn antenna through the internal scaler and the scaling test cable, and is synthesized and sent to the radar receiver through each T/R component receiving channel spatially coupled to the active phased array antenna. The safe power range of the calibration signal is primarily determined by the horn probe transmit power and the reception P-1 of the T/R assembly. The transmitting power of the probe is directly taken from the receiving output signal of the inner calibrator, and according to the radar equation:
r is the distance between the phase center of the horn antenna and the antenna array surface, lambda is the wavelength, the value is 0.03125, and C is about the insertion loss of the connecting cable according to the transmitting power Pt dBm L dB. The gain of the antenna unit is Gr dB, the gain of the probe is about Gt dB, and the transmission loss of the additional space is about S L dB, calculating T/R receiving end input power P r dBm，P r The T/R component reception dynamics are to be satisfied.
The method of the invention receives the scaling signal link and mainly comprises an internal scaling module output power P cal And scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver Manual Gain Control (MGC) (M) re ) And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
in order to balance the level of the receiving signal link of the whole system, P is connected in series in the ground test cable link r dB fixed attenuator.
Preferably, in step 3, compared with the conventional wired internal calibration method, the method disconnects the internal calibrator from the antenna calibration network port, and connects the attenuator with the horn antenna probe through a ground high-frequency test cable with a certain length to form a wireless internal calibration network, which forms a transceiver loop with the SAR antenna. In a traditional wired internal calibration method, an internal calibrator is often used for monitoring the relative changes of the amplitude and phase of each active channel of a system in an imaging process and simultaneously performing compensation and calibration, but the conventional wired internal calibration method cannot distinguish whether an inter-plate phase error comes from a main channel or a calibration channel. The invention adopts a wireless internal calibration testing method, only passes through a radio frequency transceiving link, and does not pass through an antenna calibration network, so the influence of the error of the antenna calibration network is not considered. Meanwhile, the wireless internal calibration method adopted by the invention can monitor the amplitude-phase characteristics of passive array surfaces from the T/R component to the antenna, such as a semi-rigid cable, a waveguide antenna and the like besides the amplitude-phase characteristics of the active T/R component.
Preferably, in step 4, the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receive-only, and the whole star task mode is set as earth data transmission while recording and playing; setting proper PRF and working pulse width to meet the limitation of maximum duty ratio; setting parameters such as appropriate signal bandwidth, sampling rate, sampling start, compression ratio and the like to select appropriate frame length, and meeting the limits of the maximum frame length and the minimum frame length and the data rate; setting the comprehensive service parameters of the load task starting time, the task duration, the file number, the file playback duration, the data transmission task mode and the like. And the load subsystem is used for starting up and imaging according to the parameter setting of the instruction packet, and the effective load data is transmitted underground through the data transmission channel. And the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
Preferably, in the step 5, according to engineering experience, the installation of the horn bracket and the horn antenna probe inevitably introduces measurement errors. Therefore, the spatial distance R cannot be set 0 The phase between the plates is calculated by directly substituting the phase into the spherical wave equation. The invention inverses the space distance between the horn antenna probe and the SAR antenna according to the T/R channel phase data extracted by testing or simulation, and comprises the following steps:
step 5.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance from the phase center of the horn antenna to the antenna array surface;
step 5.2: according to the phase data of each channel of each daughter board input by testing or simulation, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n K is constant for each phase of the daughter board channel n
Preferably, the step 6 mainly includes the following steps:
step 6.1: r is to be 0 Substituting the sum constant c into the formula (2), respectively fitting two curves between the phases phi and Y at two sides of each plate, and then respectively calculating the phases (Y = 0) of the two curves at the middle point, wherein the phase difference is the phase difference between the adjacent plates;
step 6.2: after compensating the phase error of each channel of the daughter board, calculating the R of each daughter board by adopting a function fitting mode 0 And a constant c;
step 6.3: r is to be 0 Substituting the sum constant c into the formula (2), respectively fitting two curves between the phases phi and Y at two sides of each plate, and then respectively calculating the phases (Y = 0) of the two curves at the middle point, wherein the phase difference is the phase difference between the adjacent compensated plates;
step 6.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
The compensated inter-plate phase error result meets the system error requirement, and the channel is verified to be stable to the system state after the inter-plate phase error compensation.
Example 4:
example 4 is a preferred example of example 1, and the present invention will be described in more detail.
The effect of the present invention will be further described with reference to the simulation data.
Typical parameters of the X-band spaceborne SAR are taken in the test and are shown in the table 1. Firstly, a wireless internal calibration state is established, a standard BJ100 model X wave band horn probe and a set of fine tuning support are selected, the horn probe is accurately aimed at the geometric mechanical position centers of an A point and a B point, the distance between the horn probe and an antenna array surface is about 3m, SAR antennas are arranged and the horn probe is arranged as shown in a figure 2-3, wherein the A point is positioned at the geometric position center of a 60 th channel of the daughter board 1 and a 61 th channel of the daughter board 2, and the B point is positioned at the geometric position center of a 121 th channel of the daughter board 3 and a 120 th channel of the daughter board 2.
Table 1 example input parameters
According to the input system requirement parameters given in the table 1, after the horn probe is aimed at the A-B position, the method is utilized to fit R to the input T/R channel phase data 0 And constant c, completing the spatial distance R 0 And (5) accurately calibrating.
TABLE 2 spatial distance R 0 Accurate calibration result
| Point number | Sub-board | Number of channels | R 0 | c |
| A | 1 | 1-60 | 3.06 | 654.8 |
| A | 2 | 61-120 | 2.876 | 579.2 |
| B | 2 | 61-120 | 2.991 | 644.6 |
| B | 3 | 121-180 | 2.918 | 585.8 |
R is to be 0 And the constant c is substituted into the formula (2), and two curves between the phases phi and Y are respectively fitted at the two sides between the plates, as shown in the following figure 5. When Y =0, the phase between each plate is calculated, and the phase difference is the phase difference between the adjacent plates.
TABLE 3 center phase difference measurement between plates
By monitoring the phase error of the main path of the single T/R channel between the daughter boards, the invention finds that the phase error of two adjacent channels between the daughter board 1 and the daughter board 2 is about 0.905654rad to the maximum, the phase error between the daughter boards 1 is higher than that of the daughter boards 2, and the phase error of the daughter board 3 is lower than that of the daughter board 2. Therefore, the present invention can trim the inter-board phase error by subtracting 0.905654rad from the channel phase original value of the daughter board 1 (1-60) and adding 0.14024rad to the channel phase original value of the daughter board 3 (121-180).
Accurately calibrating the spatial distance of the trimmed original phase data of each channel, and calculating R by fitting 0 And a constant c.
TABLE 4 compensated rear spatial distance R 0 Accurate calibration result
| Point number | Sub-board | Channel | R 0 | c | |
| | Daughter board | 1 | 1-60 | 3.06 | 653.9 |
| B | Daughter board 3 | 121-180 | 2.918 | 585.9 |
R is to be 0 And the constant c is brought into equation (2), and two curves between the phase and Y are respectively fitted on both sides of the plate, as shown in fig. 6 below. When Y =0, the phase between each plate is respectively calculated, and the phase difference is the phase difference between the compensation rear plates.
TABLE 5 center phase difference measurement results between compensated backplates
The phase error between the SAR antenna boards is measured and compensated through the method, the phase error between the daughter board 1 and the daughter board 2 after compensation is better than 0.00565rad, the phase error between the daughter board 2 and the daughter board 3 is better than 0.04024rad and is less than 5.625 degrees, and the system state is stable. Therefore, the effectiveness of the phase error compensation method between the light small SAR satellite antenna plates provided by the invention can be verified through simulation analysis.
Those skilled in the art will appreciate that, in addition to implementing the systems, apparatus, and various modules thereof provided by the present invention in purely computer readable program code, the same procedures can be implemented entirely by logically programming method steps such that the systems, apparatus, and various modules thereof are provided in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system, the apparatus, and the modules thereof provided by the present invention may be considered as a hardware component, and the modules included in the system, the apparatus, and the modules for implementing various programs may also be considered as structures in the hardware component; modules for performing various functions may also be considered to be both software programs for performing the methods and structures within hardware components.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (10)
1. A phase error compensation method between light small satellite SAR antenna boards is characterized by comprising the following steps:
step S1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
step S2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
and step S3: carrying out space distance calibration on the data after data processing and analysis;
and step S4: and calculating the phase error between the plates according to the calibrated space distance.
2. The light small-sized satellite SAR antenna inter-board phase error compensation method of claim 1, characterized in that in the step S1:
aiming the horn antenna probe and the SAR antenna array plane by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array plane and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relationship between the laser range finder and the horn probe, and calculating the specific position relationship between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, coupling to each T/R assembly receiving channel of an active phased array antenna through space, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R assembly, the transmitting power of the probe is taken from the receiving output signal of the internal calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm, the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r The receiving dynamic state of the T/R component is met;
the receiving scaling signal chain comprises an internal scaling module output power P cal And scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver manual gain control M re And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
series connection P in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
3. The light small-sized satellite SAR antenna inter-board phase error compensation method of claim 1, characterized in that in the step S2:
the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission and recording and simultaneous discharging; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
4. The light small-sized satellite SAR antenna inter-board phase error compensation method of claim 1, characterized in that in the step S3:
and inverting the spatial distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, and comprising the following steps of:
step S3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance between the phase center of the horn antenna and the antenna array surface;
step S3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n For each daughter board channel n phase, k is constant
5. The light small-sized satellite SAR antenna inter-board phase error compensation method of claim 1, characterized in that in the step S4:
step S4.1: r is to be 0 And a constant c is substituted into the formula, and the two sides between the plates are respectivelyFitting two curves between the phases phi and Y, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are calculated;
step S4.2: after the phase errors of the channels of the daughter boards are compensated, the R of each daughter board is calculated by adopting a function fitting mode 0 And a constant c;
step S4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y on two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
step S4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
6. A phase error compensation system between light small-sized satellite SAR antenna boards is characterized by comprising:
a module M1: calibrating the position of a horn antenna, calculating the level of a radio frequency link, and establishing a wireless internal calibration test state;
a module M2: setting a radar load working parameter instruction packet mode and parameters, carrying out load starting imaging, and processing and analyzing load data;
a module M3: carrying out spatial distance calibration on the data after data processing and analysis;
a module M4: and calculating the phase error between the plates according to the calibrated space distance.
7. The system for phase error compensation between light small satellite SAR antenna panels as claimed in claim 6, characterized in that in the module M1:
aiming the horn antenna probe and the SAR antenna array plane by adopting a gradienter, ensuring that the horn antenna probe is parallel to the SAR antenna array plane and ensuring that the horn antenna probe is vertical to the ground; fixing a laser range finder on the horn antenna probe, measuring the relative position relation between the laser range finder and the horn probe, and calculating the specific position relation between the horn probe and the SAR antenna array surface;
receiving a calibration signal link, transmitting an output signal of a frequency modulation signal source to a horn antenna through an inner calibrator and a calibration test cable, coupling to each T/R assembly receiving channel of an active phased array antenna through space, and sending the synthesized signal to a radar receiver; the safe power range of the calibration signal is determined by the transmitting power of the horn probe and the receiving of the T/R assembly, the transmitting power of the probe is taken from the receiving output signal of the internal calibrator, and according to the radar equation:
wherein, R is the distance between the phase center of the horn antenna and the antenna array surface, and lambda is the wavelength;
according to the transmitting power Pt dBm, the insertion loss C of the connecting cable L dB. The gain of the antenna unit is Gr dB, the gain of the probe is Gt dB, and the transmission loss of the additional space is S L dB, calculating T/R receiving end input power P r dBm，P r The receiving dynamic state of the T/R component is met;
the receiving scaling signal chain comprises an internal scaling module output power P cal Scaling test cable insertion loss C L Horn antenna gain G t Probe to antenna array coupling attenuation S L Antenna receiving gain G r Microwave combined insertion loss M L Receiver gain G re Receiver manual gain control M re And calculating the total power of the receiving levels of the whole link as follows:
P r ＝P cal +C L +G t +S L +G r +M L +G re +M re
p series connection in ground test cable link r A fixed attenuator in dB;
and disconnecting the internal calibrator from the antenna calibration network port, connecting the attenuator with the horn antenna probe through a ground high-frequency test cable with a preset length to form a wireless internal calibration network, and forming a transceiving loop with the SAR antenna.
8. The system for phase error compensation between light small satellite SAR antenna panels as claimed in claim 6, characterized in that in said module M2:
the load imaging mode is set as a continuous test calibration mode, the calibration mode is set as continuous single T/R calibration, the load working mode is set as receiving only, and the whole satellite task mode is set as earth data transmission and recording and simultaneous discharging; setting PRF and working pulse width to meet the limitation of maximum duty ratio; setting signal bandwidth, sampling rate, sampling start and compression ratio, selecting frame length, and satisfying the limitation of maximum frame length, minimum frame length and data rate; setting comprehensive service parameters including load task starting time, task duration, file number, file playback duration and data transmission task mode; the load subsystem carries out startup imaging according to the parameter setting of the instruction packet, and effective load data are transmitted underground through a data transmission channel; and the ground extracts the phase value of the peak value point of each T/R channel by carrying out pulse pressure processing on the load data.
9. The system for phase error compensation between light small satellite SAR antenna panels as claimed in claim 6, characterized in that in said module M3:
and inverting the space distance between the horn antenna probe and the SAR antenna according to the extracted T/R channel phase data, wherein the method comprises the following steps:
module M3.1: according to the geometrical relationship among the horn probe, the center between the plates and the waveguide, the following relationship is established:
wherein R is n Representing the distance between the phase center of the horn and the nth waveguide; y is n Denotes the distance between the center O' of the plate and the nth waveguide, R 0 The distance between the phase center of the horn antenna and the antenna array surface;
module M3.2: according to the input phase data of each channel of each daughter board, fitting the R of each daughter board by adopting a function fitting mode 0 And a constant c;
wherein phi is n For each daughter board channel n phase, k is constant
10. The system for phase error compensation between light small satellite SAR antenna panels as claimed in claim 6, characterized in that in the module M4:
module M4.1: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, and respectively calculating the phase difference between adjacent plates when the phases at the middle points are respectively calculated;
module M4.2: after the phase errors of the channels of the daughter boards are compensated, the R of each daughter board is calculated by adopting a function fitting mode 0 And a constant c;
module M4.3: r is to be 0 Substituting the sum constant c into a formula, respectively fitting two curves between the phases phi and Y at two sides of each plate, respectively calculating the phase at the midpoint, wherein the phase difference is the phase difference between adjacent compensated plates;
module M4.4: and generating a wave control code by the inter-plate error, and injecting the wave control code to the load subsystem in a remote control mode.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116299246A (en) * | 2023-05-19 | 2023-06-23 | 中国科学院空天信息创新研究院 | Method for evaluating internal calibration precision of synthetic aperture radar system |
| CN117518109A (en) * | 2024-01-04 | 2024-02-06 | 中国科学院空天信息创新研究院 | Temperature change characteristic measurement method for calibration network of azimuth multichannel spaceborne SAR antenna |
| CN118191767A (en) * | 2024-05-16 | 2024-06-14 | 中国科学院空天信息创新研究院 | Dynamic measurement method for amplitude-phase error among multichannel spaceborne SAR channels |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116299246A (en) * | 2023-05-19 | 2023-06-23 | 中国科学院空天信息创新研究院 | Method for evaluating internal calibration precision of synthetic aperture radar system |
| CN116299246B (en) * | 2023-05-19 | 2023-07-21 | 中国科学院空天信息创新研究院 | Method for evaluating internal calibration precision of synthetic aperture radar system |
| CN117518109A (en) * | 2024-01-04 | 2024-02-06 | 中国科学院空天信息创新研究院 | Temperature change characteristic measurement method for calibration network of azimuth multichannel spaceborne SAR antenna |
| CN117518109B (en) * | 2024-01-04 | 2024-03-12 | 中国科学院空天信息创新研究院 | Temperature change characteristic measurement method for calibration network of azimuth multichannel spaceborne SAR antenna |
| CN118191767A (en) * | 2024-05-16 | 2024-06-14 | 中国科学院空天信息创新研究院 | Dynamic measurement method for amplitude-phase error among multichannel spaceborne SAR channels |
| CN118191767B (en) * | 2024-05-16 | 2024-07-19 | 中国科学院空天信息创新研究院 | Dynamic measurement method for amplitude-phase error among multichannel spaceborne SAR channels |
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