CN112526227A - Method and device for measuring antenna direction characteristics of satellite-borne microwave radiometer - Google Patents
Method and device for measuring antenna direction characteristics of satellite-borne microwave radiometer Download PDFInfo
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- G—PHYSICS
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Abstract
The invention discloses a method and a device for measuring the antenna direction characteristic of a satellite-borne microwave radiometer. The measuring method comprises the following steps: acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun; aligning a yaw axis of the satellite-borne microwave radiometer with the sun, planning a stationary orbit satellite to rotate for a circle by taking the sun as a center in a horizontal plane and a vertical plane which are vertical to each other, and collecting and storing a rotation angle of the stationary orbit satellite and a voltage value of the satellite-borne microwave radiometer; after the data acquisition is finished, aligning the yaw axis of the satellite-borne microwave radiometer to the geocenter, and transmitting the data stored on the geostationary orbit satellite to the ground; processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value; and obtaining a main lobe directional diagram and a side lobe directional diagram of the satellite-borne microwave radiometer antenna according to the processed data.
Description
Technical Field
The invention relates to a method for measuring the antenna direction characteristic of a satellite-borne microwave radiometer, and simultaneously relates to a corresponding measuring device, belonging to the technical field of satellite remote sensing.
Background
The satellite-borne microwave radiometer is a high-sensitivity receiving device which can judge temperature and humidity curves by passively receiving microwave signals of temperature radiation transmitted from various heights and can quantitatively measure low-level microwave radiation of targets (such as ground objects and various components of the atmosphere).
In the prior art, the convenience of satellite-borne microwave radiometers in acquiring global data from the altitude of geostationary orbit satellites has become an important means for observing the earth from geostationary orbit satellites. In microwave and millimeter wave bands, a satellite-borne microwave radiometer carried by a stationary orbit satellite observes the directional characteristics (also called directional diagram) of an antenna through a near field in a ground laboratory, and determines the gain of a main lobe and a side lobe.
After a satellite-borne microwave radiometer loaded by a geostationary orbit satellite enters a geostationary orbit, the directional characteristic of an antenna of the satellite-borne microwave radiometer after the satellite-borne microwave radiometer is in orbit can be changed undoubtedly through the vibration in the rocket launching process and the stress change in the space under the microgravity state. If the actual directional diagram can be obtained, quantitative correction can be carried out on the data acquired in the on-orbit process; or the directional characteristic of the antenna is known in advance, such as the side lobe condition deviating from the main lobe within a certain angle range, and when the sun enters a certain side lobe to reach an interference threshold, the avoidance is carried out when the working mode of the geostationary orbit satellite is designed.
In order to meet the above requirements, it is a key of the satellite-borne microwave radiometer to realize on-orbit measurement of the antenna direction, and one of the technical problems to be solved at present is urgent.
Disclosure of Invention
The invention aims to solve the primary technical problem of providing a method for measuring the antenna directional characteristic of a satellite-borne microwave radiometer.
The invention aims to solve another technical problem of providing a device for measuring the antenna directional characteristic of a satellite-borne microwave radiometer.
In order to achieve the purpose, the invention adopts the following technical scheme:
according to a first aspect of the embodiments of the present invention, there is provided a method for measuring antenna directional characteristics of a satellite-borne microwave radiometer, including the following steps:
acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun;
aligning the yaw axis of the satellite-borne microwave radiometer with the sun, planning the geostationary orbit satellite to rotate for a circle by taking the sun as a center in a horizontal plane and a vertical plane which are vertical to each other, and collecting and storing the rotation angle of the geostationary orbit satellite and the voltage value which is output by the satellite-borne microwave radiometer and changes along with time and corresponds to the rotation angle;
after the data acquisition is finished, aligning the yaw axis of the satellite-borne microwave radiometer with the geocentric, and transmitting data which are stored on the geostationary orbit satellite and comprise the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value to the ground;
processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
and obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
Preferably, in the process of collecting the rotation angle of the geostationary orbit satellite and the voltage value which is output by the satellite-borne microwave radiometer and changes along with the time and corresponds to the rotation angle, the data sampling of the satellite-borne microwave radiometer and the data sampling of the geostationary orbit satellite are kept synchronous in time.
Preferably, during the process of acquiring data in the horizontal plane: aligning a yaw axis of the geostationary orbit satellite with the sun, and controlling a pitch axis rotation angular velocity of the geostationary orbit satellite to bring the geostationary orbit satellite into a plane with the sun, comprising the sub-steps of:
if the rotation direction of the pitching axis is consistent with the running direction of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
the rotating angular speed in the same direction T1 time is 360/T1-360/T
If the pitch axis rotation is opposite to the direction of the operation of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
the rotation angular speed in the reverse T1 time is 360/T1+360/T
Wherein T is the time of one rotation of the earth; t1 is the time for the geostationary orbit satellite to complete one revolution; the unit of the rotation angular velocity of the pitch axis of the stationary orbit satellite is degree/second.
Preferably, in the process of acquiring data in a vertical plane, the yaw axis of the geostationary orbit satellite is aligned with the sun, and the roll axis rotation angular velocity of the geostationary orbit satellite is controlled to enable the geostationary orbit satellite and the sun to be in a plane, and the method comprises the following sub-steps:
if the pitch axis rotation is opposite to the direction of the operation of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
angular velocity of rotation 360/T in reverse T1 time
Wherein T is the time of one rotation of the earth; t1 is the time for the geostationary orbit satellite to complete one revolution; the unit of the rotational angular velocity of the roll axis of the stationary orbiting satellite is degrees/second.
Preferably, in the process of collecting the antenna main lobe data of the satellite-borne microwave radiometer, when the geostationary orbit satellite enters the sun, the attenuator is connected in advance by 10% -20% of the sun aperture angle;
accordingly, the attenuator is switched out after the geostationary orbit satellite passes the sun with a lag of 10% to 20% of the sun opening angle.
Preferably, the attenuator is not added in all angular ranges except for the alignment of the antenna with the sun in the process of collecting the antenna sidelobe data of the satellite-borne microwave radiometer.
Preferably, the step of processing the data including the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value includes the following sub-steps:
restoring the voltage value of the satellite-borne microwave radiometer during the period of accessing the attenuator;
removing a corresponding voltage value and an angle during the field angle of the sun from data comprising a horizontal observation voltage value and a vertical observation voltage value of the satellite-borne microwave radiometer;
and obtaining a two-dimensional function sigma (VH, theta H.) of the voltage and the angle of the satellite-borne microwave radiometer on the horizontal plane and a two-dimensional function sigma (VV, theta V.) of the voltage and the angle of the vertical plane.
Preferably, the step of obtaining the main lobe and side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer comprises the following substeps:
a rectangular coordinate system is established, in which a two-dimensional function Σ (VH, θ H.) of voltage and angle for the horizontal plane and a two-dimensional function Σ (VV, θ V.) of voltage and angle for the vertical plane are illustrated, the horizontal axis of the rectangular coordinate system is the angle θ and the vertical axis thereof is the voltage value V.
Preferably, the satellite-borne microwave radiometer is mounted in a manner that when the rotation angle of the antenna is set to be 0 degree, the main lobe direction of the antenna is consistent with the yaw axis direction of the geostationary orbit satellite pointing to the earth center.
According to a second aspect of the embodiments of the present invention, there is provided a device for measuring antenna directional characteristics of a satellite-borne microwave radiometer, including a processor and a memory, where the processor reads a computer program in the memory, and is configured to perform the following operations:
acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun;
acquiring data comprising the rotation angle value of the stationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
and obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
Compared with the prior art, the invention creatively utilizes the energy provided by the sun and the sun to realize data acquisition, restores the yaw axis to be aligned with the geocentric state after observation is finished, and transmits the data which are stored on the geostationary orbit satellite and comprise the rotation angle of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle to the ground. The invention can effectively solve the technical problem of on-orbit measurement of the antenna directional pattern of the satellite-borne microwave radiometer.
Drawings
FIG. 1 is a flowchart of a method for measuring the antenna directional characteristic of a satellite-borne microwave radiometer according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a geostationary orbit satellite rotating 360 degrees around the sun in a horizontal plane and a vertical plane, respectively, according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a horizontal plane and a vertical plane of an antenna directional diagram of a satellite-borne microwave radiometer according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a directional diagram of an antenna of a satellite-borne microwave radiometer obtained through data processing according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a device for measuring the directional characteristic of an antenna of a satellite-borne microwave radiometer according to an embodiment of the present invention.
Detailed Description
The technical contents of the invention are described in detail below with reference to the accompanying drawings and specific embodiments.
The sun is the sidereal closest to the earth and is the central celestial body of the solar system. 99.87% of the solar system is concentrated in the sun, and the strong attraction of the solar system controls the movement of planets such as big planets, comets and the like. For measuring the antenna direction of the satellite-borne microwave radiometer, the sun can be used for providing energy which is stable and not too strong. Therefore, the overall technical concept of the invention is as follows: based on the sun, which is the running center of each planet including the earth, the method for measuring the antenna direction characteristic of the satellite-borne microwave radiometer by using the sun is creatively provided, and the problem of on-orbit measurement of the antenna directional pattern of the satellite-borne microwave radiometer is solved. Here, the satellite-borne microwave radiometer means that the satellite-borne microwave radiometer is installed on an orbiting stationary orbit satellite.
Example 1:
the embodiment 1 of the invention provides a method for measuring the antenna directional pattern of a satellite-borne microwave radiometer in an on-orbit mode and measuring the antenna directional characteristic of the satellite-borne microwave radiometer by using the sun. The measuring method comprises a plurality of steps, and all the steps are mutually related.
As shown in fig. 1, the method for measuring the antenna directional characteristic of the satellite-borne microwave radiometer mainly comprises the following steps:
step S1) obtains data including orbit parameters and attitudes of the geostationary orbit satellite, and obtains a position, a movement direction, and a movement speed of the sun.
The satellite-borne microwave radiometer is arranged on a static orbit satellite. The geostationary orbit satellite is also called a 24-hour orbit, which means that an orbital plane coincides with an equatorial plane, the orbital period of the geostationary orbit satellite is equal to the rotation period of the earth in an inertial space (23 hours, 56 minutes and 4 seconds), and the direction of the geostationary orbit satellite is consistent with the rotation period, namely, the geostationary orbit satellite is located in an orbit with a relatively unchanged position with respect to the ground, so the orbit is also called a geostationary satellite orbit.
The ephemeris (position in inertial space) of the sun can be accurately predicted. In this step, data including orbit parameters and attitudes of the geostationary orbit satellite are acquired, so that the position, direction and speed of the sun can be accurately predicted according to the orbit parameters, attitudes and the like of the geostationary orbit satellite. The orbital parameters herein are understood to mean the position of the geostationary orbit satellite in space, and the attitude is understood to mean the orientation of the geostationary orbit satellite.
The position of the geostationary orbit satellite in space at any time in the future can be accurately forecasted by using the orbit parameters of the geostationary orbit satellite, and the attitude of the geostationary orbit satellite can be acquired in real time by using an attitude measurement device carried by the geostationary orbit satellite. The earth revolves around the sun and rotates (synchronously rotates with a stationary orbit satellite), the observation of the antenna directional diagram of the satellite-borne microwave radiometer is finished in a short time (in hours), so that the position of the sun can be regarded as fixed and the rotation factor of the earth is only considered. The observation is based on a stationary orbit satellite as a reference and is equivalent to the movement of the sun, so that the position, the movement direction and the movement speed of the sun are predicted in advance.
Step S2) aligning the yaw axis of the satellite-borne microwave radiometer with the sun, planning the rotation of the geostationary orbit satellite in a horizontal plane and a vertical plane which are vertical to each other by taking the sun as a center, and collecting and storing the rotation angle value of the geostationary orbit satellite and the voltage value which is output by the satellite-borne microwave radiometer and changes along with time and corresponds to the rotation angle value.
The instrument coordinate system of the satellite-borne microwave radiometer is assumed to be coincident with the body coordinate system of the geostationary orbit satellite, and the geostationary orbit satellite is planned to rotate for a circle (360 degrees) on two planes (a horizontal plane and a vertical plane) which are perpendicular to each other by taking the sun as the center. During the data acquisition process in the step, the data sampling of the voltage value of the satellite-borne microwave radiometer and the data sampling of the motion angle value of the geostationary orbit satellite are kept synchronous in time, namely, the acquired data comprises the angle of the geostationary orbit satellite during the rotation process and the corresponding voltage value output by the satellite-borne microwave radiometer. The task process of this step please refer to fig. 2. In fig. 2, the geostationary orbit satellite rotates 360 degrees around the sun in the horizontal plane and the vertical plane, respectively.
In order to ensure the earth observation, the satellite-borne microwave radiometer is generally installed such that when the antenna rotation angle is 0 degree, the maximum gain direction of the antenna, i.e., the main lobe direction, coincides with the axis (yaw axis) of the geostationary orbit satellite pointing to the earth center. The origin of the main lobe is related to the antenna directivity, and the "antenna directivity" refers to the relation between the relative value of the antenna radiation field and the spatial direction under the condition of the same distance r in the far zone. The antenna directivity is expressed by an antenna directional diagram, the antenna directional diagram is generally in a petal shape, and a beam within the first zero radiation direction line on two sides of the maximum radiation direction is called a main lobe. As shown in fig. 3, a yaw axis of the geostationary orbit satellite is defined to point to the center of the sun, and a plane formed by rotation around a pitch axis of the geostationary orbit satellite is defined as a horizontal plane; the yaw axis of the geostationary orbit satellite points to the center of the sun, and the plane formed by the rotation around the rolling axis of the geostationary orbit satellite is a vertical plane. Thus, a horizontal plane directional diagram and a vertical plane directional diagram are obtained respectively through observation.
According to the definition, during the course of one revolution of the geostationary orbit satellite, the sun moves relative to the geostationary orbit satellite due to the synchronous motion of the geostationary orbit satellite and the earth rotation, and the sun is ensured to be in the horizontal plane and the vertical plane during the whole 360-degree rotation observation process. Therefore, the geostationary orbit satellite is controlled to compensate for the movement of the sun during observation, resulting in a different method of observation compensation for the horizontal and vertical planes, as will be described in detail below.
Firstly, horizontal plane observation task planning:
when the horizontal plane is observed, after the yaw axis of the geostationary orbit satellite is aligned to the sun, the geostationary orbit satellite and the sun can be controlled to be in the same plane, and observation is completed by controlling the rotation of the pitch axis. Since the satellite is far away from the sun, the change in rotation angle between the sun and the satellite can be equivalent to the rotational angular velocity of the earth:
angular velocity of the earth 360/T (1)
Wherein, T is the time of one revolution of the earth, namely the time of one day, and the unit of the rotational angular velocity of the earth is degree/second.
If the planned pitch axis rotation is consistent with the direction of the satellite in the stationary orbit and is completed within the time T1, the rotation angular velocity is controlled as follows:
rotation angular velocity in the same direction T1 time 360/T1-360/T (2)
If the planned pitch axis rotation is completed within the time T1, opposite to the direction of travel of the stationary orbit satellite, the angular velocity of rotation is controlled to be:
angular velocity of rotation in reverse T1 time 360/T1+360/T (3)
The whole link of the satellite-borne microwave radiometer receiving and outputting the sun signals cannot generate saturated or nonlinear response, so that special design needs to be made for observation to meet the requirement, and observation distortion can be caused. If the main lobe of the antenna is aligned with the sun during observation, the output signal is distorted due to over-strong input signal. It can be calculated analytically in advance for this case. In the embodiment of the invention, through system design, distortion can be caused to appear in a circuit part after frequency conversion instead of a radio frequency front end, and the authenticity of observed data can be ensured by accessing an attenuator (the attenuation is A decibel and is about 10 decibels). And the attenuator access and switch-out control plan is automatically executed by the control of the geostationary orbit satellite in the whole observation process. The solar field angle is about 31 '59' (about 0.5 degree), the attenuator is connected in advance by 10 percent to 20 percent (preferentially 20 percent) of the solar field angle, so that the attenuator plays a role in data attenuation; correspondingly, after passing through the sun, the attenuator is switched out at the solar opening angle with 10% -20% (preferably 20%), and the data attenuation function of the attenuator is switched off.
The bright temperature of the sun in the microwave band is about 5500K. In the embodiment of the invention, whether the antenna passes through the sun can be accurately calculated in advance. In order to ensure that the main lobe of the antenna of the satellite-borne microwave radiometer is not distorted when passing through the sun, an A decibel attenuator is connected into a static orbit satellite circuit under proper time control. And when the main lobe of the antenna passes through the sun, the attenuator is turned on, so that the whole link works in a linear region. Whereas the side lobe gain is low and can only be measured when receiving a high radiation source. Therefore, in the process of observing the antenna side lobe of the satellite-borne microwave radiometer, no attenuator is added in all the angular ranges except the range where the antenna is aligned with the sun. That is to say, when measuring the antenna side lobe of the satellite-borne microwave radiometer, the attenuator is closed, the characteristic of high flux radiation (high radiation energy) of the sun is just utilized, and the side lobe characteristic which is dozens of decibels lower than the main lobe can be directly measured. It should be understood that the high flux radiant energy is not as high as possible, and is selected based on the performance of the microwave radiometer itself.
In the embodiment of the invention, attenuation and on-off control design is specially carried out for observation by utilizing the sun. The attenuator is a conventional device in the industry, and the working principle of the attenuator is not described in detail here. By using the attenuator, the main lobe of the antenna can be prevented from being saturated when passing through the sun, and the side lobe of the antenna can be observed by using the high radiation flux of the sun.
And controlling the geostationary orbit satellite to complete observation in a horizontal plane. In the horizontal plane observation process, the satellite-borne microwave radiometer obtains a group of remote sensing data, including a horizontal observation voltage Value (VH) of the satellite-borne microwave radiometer, a rotation angle value (theta H) corresponding to the VH, and time (t). Since the observed voltage Value (VH) and the rotation angle value (θ H) are functions of time (t), and the attenuator access and cut-out control is planned in advance, the time and angle of accessing the attenuator and passing through the sun are known.
Secondly, planning of observation tasks of the vertical plane:
during observation of the vertical surface, after the yaw axis is aligned to the sun, the observation is completed by controlling the rolling axis of the stationary orbit satellite to rotate 360 degrees, and the observation is also completed within the time T1. Due to the relative motion between the sun and the geostationary orbit satellite, the yaw axis pointing to the sun gradually deviates, and in order to ensure that the yaw axis does not deviate, the yaw axis and the operation direction of the geostationary orbit satellite rotate in opposite directions by controlling the pitch axis, and the rotation angular speed is as follows:
angular velocity of rotation 360/T (4) in reverse T1 time
In addition, as with the level observation mission planning, attenuator on and off controls are planned as the geostationary orbit satellite enters or passes the sun, and are not described in detail herein.
And controlling the geostationary orbit satellite to complete observation on a vertical plane. In the process of observing the vertical surface, the satellite-borne microwave radiometer obtains a group of remote sensing data, including the vertical observation Voltage Value (VV) of the satellite-borne microwave radiometer, and the rotation angle value (theta V) and the time (t) corresponding to the vertical observation Voltage Value (VV).
Step S3), after the data acquisition is finished, aligning the yaw axis of the satellite-borne microwave radiometer with the geocentric, and transmitting the data which are stored on the geostationary orbit satellite and comprise the rotation angle of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle to the ground.
According to the method for measuring the antenna direction characteristics of the satellite-borne microwave radiometer, data acquisition is achieved by means of the energy provided by the sun and the energy provided by the sun, after observation is completed, the yaw axis is restored to be aligned with the geocentric state, and data including the rotation angle of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle of the geostationary orbit satellite are stored on the geostationary orbit satellite and transmitted to the ground. It should be understood here that the observation of the horizontal plane and the vertical plane of the satellite-borne microwave radiometer can be completed in sequence, and the sequence is not limited; meanwhile, the position of the sun is also changing during the observation of the rotating yaw axis. In the step, after the data acquisition is finished, the earth observation and communication state of the satellite-borne microwave radiometer is recovered, and data such as a horizontal observation voltage Value (VH) of the satellite-borne microwave radiometer, a rotation angle value (theta H) corresponding to the VH, time (t), a vertical observation Voltage Value (VV) of the satellite-borne microwave radiometer, a rotation angle value (theta V) corresponding to the VV, time (t) and the like are transmitted to the ground.
The on-board microwave radiometer is always located on a stationary orbiting satellite, only to transmit data back to the surface during this step. In the above steps, the control of the horizontal plane, the vertical plane and the ground state is realized by the maneuvering control of the geostationary orbit satellite, and the detailed description is omitted.
Step S4) processing the data including the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value.
When the horizontal plane and the vertical plane rotate for one circle to observe the sun, the satellite-borne microwave radiometer obtains a group of remote sensing data, including an observation voltage value (V) of the satellite-borne microwave radiometer, a rotation angle value (theta) corresponding to the observation voltage value (V) and the rotation angle value (theta) and corresponding time t. After the data are transmitted to the ground, the data including the horizontal observation voltage Value (VH) of the satellite-borne microwave radiometer, the rotation angle value (theta H) corresponding to the horizontal observation voltage Value (VH), the time (t), the vertical observation Voltage Value (VV) of the satellite-borne microwave radiometer, the rotation angle value (theta V) corresponding to the vertical observation Voltage Value (VV) and the time (t) are processed, the data are restored to normal values, and the relationship among the voltage value, the sun and the rotation angle is accurately calculated.
The recovery data at least comprises A decibels compressed by a circuit of the satellite-borne microwave radiometer within the range of the field angle of the observation sun, and the A decibels are amplified and restored after reaching the ground. As mentioned above, it is not a point source due to the sun's opening angle of about 0.5 degrees. The width of the main lobe of the antenna of the satellite-borne microwave radiometer is far less than 0.5 degree, so that a constant-amplitude voltage value with a certain width can be generated when the antenna sweeps across the sun. The voltage value is compressed by A decibels in amplitude and then multiplied by an amplification factor in the subsequent calculation process.
In this step, the data is sent to the surface for processing. When observing on a horizontal plane and a vertical plane, a main lobe and a side lobe need to be distinguished, and multiple groups of data corresponding to the number of antenna lobes are processed. The specific treatment process comprises the following steps:
step S41): and recovering the voltage value of the satellite-borne microwave radiometer during the access of the attenuator.
In this step, the voltage value during the switching in of the attenuator is restored, i.e. the data is multiplied by 10 (A/10).
Step S42): and removing the corresponding voltage value and angle during the field angle of the sun from the data comprising the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
In this step, the voltage values and angles corresponding to the sun during the sun's opening angle (31 ' 59 ") are removed and the remaining data minus the sun's opening angle are concatenated with the previous data.
Step S43): and obtaining a two-dimensional function sigma (VH, theta H.) of the voltage and the angle of the satellite-borne microwave radiometer on the horizontal plane and a two-dimensional function sigma (VV, theta V.) of the voltage and the angle of the vertical plane.
In this step, two arrays Σ (VH, θ H.) and Σ (VV, θ V.) of the space-borne microwave radiometer observed in the horizontal plane and the vertical plane are obtained, respectively, each array being a two-dimensional function of voltage and angle.
Step S5), obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
In this step, a rectangular coordinate system is established, and a two-dimensional function Σ (VH, θ H.) of voltage and angle corresponding to the horizontal plane of the satellite-borne microwave radiometer and a two-dimensional function Σ (VV, θ V.) of voltage and angle corresponding to the vertical plane are illustrated. And (5) carrying out graphic representation on the processed data through a rectangular coordinate system to obtain a directional diagram of the antenna of the satellite-borne microwave radiometer. The horizontal axis of the rectangular coordinate system is an angle theta, the vertical axis of the rectangular coordinate system is a voltage value V, and a directional diagram, namely directional characteristics, of the satellite-borne microwave radiometer antenna can be displayed. Fig. 4 shows the directional diagram of the antenna of the satellite-borne microwave radiometer obtained through data processing.
It should be noted that the sun is a natural source of radiation. Due to its high temperature, the radiation energy in the microwave and terahertz bands is strong. The directional diagram observation of the on-orbit satellite-borne microwave radiometer by the sun needs to consider the following problems: the main lobe of the antenna of the satellite-borne microwave radiometer is aligned with the sun, so that the condensation effect cannot be caused, otherwise, high-temperature damage can be caused by long-time irradiation, and therefore, the antenna in the offset feed mode is more suitable for being used in the embodiment of the invention. The method for measuring the antenna directional characteristic of the satellite-borne microwave radiometer is suitable for the application of microwave remote sensing, terahertz technology and radiometric calibration.
In addition, the method for measuring the antenna direction characteristic of the satellite-borne microwave radiometer is considered according to the orbit of a stationary orbit satellite, and the greatest meaning is that a real antenna directional diagram of the satellite-borne microwave radiometer can be obtained by utilizing the sun. In the case of other tracks, other factors are taken into consideration as appropriate.
Example 2:
embodiment 2 of the invention provides a device for measuring the directional characteristic of an antenna of a satellite-borne microwave radiometer. As shown in fig. 5, the measuring device includes a memory 51 and a processor 52, and may further include a communication component, a sensor component, a power supply component, and an input/output interface according to actual needs. The memory, communication components, sensor components, power components, and input/output interfaces are all connected to the processor 52.
In the above apparatus, the processor 52 reads the computer program in the memory 51 for performing the following operations:
acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun;
acquiring data comprising a rotation angle value of a stationary orbit satellite and a horizontal observation voltage value and a vertical observation voltage value of a satellite-borne microwave radiometer corresponding to the rotation angle value;
processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
and obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
The measuring device provided by the embodiment of the invention can be matched with a satellite-borne microwave radiometer to realize the method for measuring the antenna direction characteristic of the satellite-borne microwave radiometer by using the sun, so that the problem of on-orbit measurement of the antenna directional diagram of the satellite-borne microwave radiometer is solved.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The specific embodiments are specific examples of implementing the technical solutions of the present invention. Also, the term "comprises/comprising" when used herein refers to the presence of a feature, integer or component, but does not preclude the presence or addition of one or more other features, integers or components.
The method and the device for measuring the antenna directional characteristic of the satellite-borne microwave radiometer provided by the invention are explained in detail above. It will be apparent to those skilled in the art that any obvious modifications thereof can be made without departing from the spirit of the invention, which infringes the patent right of the invention and bears the corresponding legal responsibility.
Claims (10)
1. A method for measuring the antenna direction characteristic of a satellite-borne microwave radiometer is characterized by comprising the following steps:
acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun;
aligning the yaw axis of the satellite-borne microwave radiometer with the sun, planning the geostationary orbit satellite to rotate for a circle by taking the sun as a center in a horizontal plane and a vertical plane which are vertical to each other, and collecting and storing the rotation angle of the geostationary orbit satellite and the voltage value which is output by the satellite-borne microwave radiometer and changes along with time and corresponds to the rotation angle;
after the data acquisition is finished, aligning the yaw axis of the satellite-borne microwave radiometer with the geocentric, and transmitting data which are stored on the geostationary orbit satellite and comprise the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value to the ground;
processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
and obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
2. The method for measuring the directional characteristic of the antenna of the satellite-borne microwave radiometer according to claim 1, wherein the data samples of the satellite-borne microwave radiometer and the data samples of the geostationary orbit satellite are kept synchronized in time during the process of collecting the rotation angle of the geostationary orbit satellite and the voltage value of the output of the satellite-borne microwave radiometer corresponding to the rotation angle with time.
3. The method for measuring the directional characteristic of the antenna of the space-borne microwave radiometer according to claim 1, wherein the yaw axis of the geostationary orbit satellite is directed to the sun during the data acquisition process in the horizontal plane, and the angular velocity of the pitch axis of the geostationary orbit satellite is controlled to make the geostationary orbit satellite and the sun be in the same plane, comprising the sub-steps of:
if the rotation direction of the pitching axis is consistent with the running direction of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
the rotating angular speed in the equidirectional T1 time is 360/T1-360/T;
if the pitch axis rotation is opposite to the direction of the operation of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
the rotation angular speed in the reverse T1 time is 360/T1+ 360/T;
wherein T is a time when the earth rotates one turn, and T1 is a time when the geostationary orbit satellite completes one turn.
4. The method for measuring the directional characteristic of the antenna of the satellite-borne microwave radiometer according to claim 1, characterized in that during the data acquisition process in the vertical plane: aligning the yaw axis of the geostationary orbit satellite with the sun, and controlling the roll axis rotation angular velocity of the geostationary orbit satellite to make the geostationary orbit satellite and the sun be in one plane, comprising the following sub-steps:
if the pitch axis rotation is opposite to the direction of the operation of the stationary orbit satellite, the rotation angular velocity is controlled as follows:
angular velocity of rotation 360/T in reverse T1 time
Wherein T is a time when the earth rotates one turn, and T1 is a time when the geostationary orbit satellite completes one turn.
5. The method for measuring the antenna directional characteristic of the satellite-borne microwave radiometer according to claim 1, wherein in the process of collecting the antenna main lobe data of the satellite-borne microwave radiometer,
when the geostationary orbit satellite enters the sun, the attenuator is accessed by 10-20% of the advance of the sun field angle;
and switching out the attenuator by the sun opening angle with 10% -20% lag after the geostationary orbit satellite passes through the sun.
6. The method for measuring the directional characteristic of the antenna of the satellite-borne microwave radiometer according to claim 5, characterized in that:
and in the process of collecting the antenna side lobe data of the satellite-borne microwave radiometer, the attenuator is not added in all the angle ranges except the range where the antenna is aligned with the sun.
7. The method for measuring the directional characteristic of the antenna of the satellite-borne microwave radiometer according to claim 5, wherein the step of processing the data including the rotation angle value of the geostationary orbit satellite and the corresponding horizontal observation voltage value and vertical observation voltage value of the satellite-borne microwave radiometer comprises the following sub-steps:
restoring the voltage value of the satellite-borne microwave radiometer during the period of accessing the attenuator;
removing a corresponding voltage value and an angle during the field angle of the sun from data comprising a horizontal observation voltage value and a vertical observation voltage value of the satellite-borne microwave radiometer;
and obtaining a two-dimensional function sigma (VH, theta H.) of the voltage and the angle of the satellite-borne microwave radiometer on the horizontal plane and a two-dimensional function sigma (VV, theta V.) of the voltage and the angle of the vertical plane.
8. The method for measuring the antenna directional characteristic of the space-borne microwave radiometer according to claim 1, wherein in the step of obtaining the main lobe and side lobe directional diagram of the antenna of the space-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the space-borne microwave radiometer, a rectangular coordinate system is established, and the rectangular coordinate system is graphically represented by a two-dimensional function Σ (VH, θ H.) of the voltage and the angle corresponding to the horizontal plane and a two-dimensional function Σ (VV, θ V.) of the voltage and the angle corresponding to the vertical plane, wherein the horizontal axis of the rectangular coordinate system is the angle θ and the vertical axis thereof is the voltage value V.
9. The method for measuring the directional characteristic of the antenna of the satellite-borne microwave radiometer according to any of claims 1-8, characterized in that:
the satellite-borne microwave radiometer is mounted in a mode that when the rotation angle of the antenna is set to be 0 degree, the main lobe direction of the antenna is consistent with the yaw axis direction of the geostationary orbit satellite pointing to the geocentric.
10. An apparatus for measuring antenna directional characteristics of a satellite-borne microwave radiometer, comprising a processor and a memory, wherein the processor reads a computer program stored in the memory, and is configured to:
acquiring data comprising orbit parameters and postures of a geostationary orbit satellite to obtain the position, the movement direction and the movement speed of the sun;
acquiring data comprising the rotation angle value of the stationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
processing data comprising the rotation angle value of the geostationary orbit satellite and the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer corresponding to the rotation angle value;
and obtaining a main lobe directional diagram and a side lobe directional diagram of the antenna of the satellite-borne microwave radiometer according to the processed data of the horizontal observation voltage value and the vertical observation voltage value of the satellite-borne microwave radiometer.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113341238A (en) * | 2021-06-08 | 2021-09-03 | 北方天穹信息技术（西安）有限公司 | Method for measuring antenna directional diagram by utilizing solar radiation |
| CN116068285A (en) * | 2022-12-28 | 2023-05-05 | 中国电信股份有限公司卫星通信分公司 | Satellite antenna network access test method and device and nonvolatile storage medium |
| TWI814539B (en) * | 2022-08-16 | 2023-09-01 | 筑波醫電股份有限公司 | Cylindrical shell detection method and cylindrical shell detection device |
| CN117572326A (en) * | 2024-01-17 | 2024-02-20 | 国家卫星气象中心(国家空间天气监测预警中心) | Radiometric calibration method and device for microwave remote sensing instrument and computer storage medium |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6031498A (en) * | 1995-09-26 | 2000-02-29 | Centre National D'etudes Spatiales | Antenna pattern measurement method and device |
| CN101975971A (en) * | 2010-09-30 | 2011-02-16 | 中国科学院国家天文台 | On-star calibration method for lunar microwave sounder |
| CN106249057A (en) * | 2016-07-28 | 2016-12-21 | 西安空间无线电技术研究所 | A kind of large-scale around focus rotation beam scanning antennas radiation characteristic equivalent detecting method |
| US20170017534A1 (en) * | 2015-07-16 | 2017-01-19 | U.S.A. As Represented By The Administrator Of The National Aeronautics And Space Administration | Method and apparatus of back lobe correction to antenna temperature for earth-observing microwave instruments |
| CN106569186A (en) * | 2015-10-13 | 2017-04-19 | 中国科学院国家空间科学中心 | Offset correction method for spaceborne microwave radiometer |
| CN109212496A (en) * | 2018-09-26 | 2019-01-15 | 西安空间无线电技术研究所 | A kind of satellite-borne microwave radiometer antenna error bearing calibration |
| CN110018364A (en) * | 2019-05-07 | 2019-07-16 | 中国人民解放军32039部队 | Antenna radiation pattern Orbital detection method, system and electronic equipment |
-
2020
- 2020-11-20 CN CN202011315028.6A patent/CN112526227B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6031498A (en) * | 1995-09-26 | 2000-02-29 | Centre National D'etudes Spatiales | Antenna pattern measurement method and device |
| CN101975971A (en) * | 2010-09-30 | 2011-02-16 | 中国科学院国家天文台 | On-star calibration method for lunar microwave sounder |
| US20170017534A1 (en) * | 2015-07-16 | 2017-01-19 | U.S.A. As Represented By The Administrator Of The National Aeronautics And Space Administration | Method and apparatus of back lobe correction to antenna temperature for earth-observing microwave instruments |
| CN106569186A (en) * | 2015-10-13 | 2017-04-19 | 中国科学院国家空间科学中心 | Offset correction method for spaceborne microwave radiometer |
| CN106249057A (en) * | 2016-07-28 | 2016-12-21 | 西安空间无线电技术研究所 | A kind of large-scale around focus rotation beam scanning antennas radiation characteristic equivalent detecting method |
| CN109212496A (en) * | 2018-09-26 | 2019-01-15 | 西安空间无线电技术研究所 | A kind of satellite-borne microwave radiometer antenna error bearing calibration |
| CN110018364A (en) * | 2019-05-07 | 2019-07-16 | 中国人民解放军32039部队 | Antenna radiation pattern Orbital detection method, system and electronic equipment |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113341238A (en) * | 2021-06-08 | 2021-09-03 | 北方天穹信息技术（西安）有限公司 | Method for measuring antenna directional diagram by utilizing solar radiation |
| TWI814539B (en) * | 2022-08-16 | 2023-09-01 | 筑波醫電股份有限公司 | Cylindrical shell detection method and cylindrical shell detection device |
| CN116068285A (en) * | 2022-12-28 | 2023-05-05 | 中国电信股份有限公司卫星通信分公司 | Satellite antenna network access test method and device and nonvolatile storage medium |
| CN117572326A (en) * | 2024-01-17 | 2024-02-20 | 国家卫星气象中心(国家空间天气监测预警中心) | Radiometric calibration method and device for microwave remote sensing instrument and computer storage medium |
| CN117572326B (en) * | 2024-01-17 | 2024-05-03 | 国家卫星气象中心(国家空间天气监测预警中心) | Radiometric calibration method and device for microwave remote sensing instrument and computer storage medium |
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|---|---|
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