CN114994622A - Static boresight method of airborne radar system based on POS - Google Patents

Static boresight method of airborne radar system based on POS Download PDF

Info

Publication number
CN114994622A
CN114994622A CN202210564654.1A CN202210564654A CN114994622A CN 114994622 A CN114994622 A CN 114994622A CN 202210564654 A CN202210564654 A CN 202210564654A CN 114994622 A CN114994622 A CN 114994622A
Authority
CN
China
Prior art keywords
prism
angle
measurement unit
pos
radar system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210564654.1A
Other languages
Chinese (zh)
Inventor
王飞
沈明星
王燕宇
张明
刘莎莎
杨毅
廉云龙
蒋千
胡松涛
张虞健
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CETC 38 Research Institute
Original Assignee
CETC 38 Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CETC 38 Research Institute filed Critical CETC 38 Research Institute
Priority to CN202210564654.1A priority Critical patent/CN114994622A/en
Publication of CN114994622A publication Critical patent/CN114994622A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/40—Means for monitoring or calibrating
    • G01S7/4004—Means for monitoring or calibrating of parts of a radar system
    • G01S7/4026—Antenna boresight

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Navigation (AREA)

Abstract

The invention discloses a static boresight method of an airborne radar system based on POS, belonging to the technical field of unmanned airborne SARMTI reconnaissance monitoring radar; the static target calibration method of the unmanned airborne radar system based on the POS efficiently and conveniently solves the problems that the traditional unmanned airborne SARMTI reconnaissance monitoring radar needs to carry out calibration of installation errors when each set of equipment is installed, so that the system maintenance time and cost are high, and even the operational efficiency of the equipment is reduced, so that the equipment maintenance time and cost are greatly saved, and the maintainability and the operational efficiency of the equipment are improved.

Description

Static boresight method of airborne radar system based on POS
Technical Field
The invention relates to the technical field of unmanned airborne SARMTI reconnaissance monitoring radars, in particular to a static boresight method of an airborne radar system based on POS.
Background
With the rapid development of electronic communication technology, the SARMTI reconnaissance surveillance radar technology suitable for the unmanned aerial vehicle platform is rapidly developed, the functions and the performance are continuously enhanced, and the combat efficiency and the survival capability of the unmanned battlefield in the future are greatly improved. The unmanned airborne SARMTI reconnaissance surveillance radar system has the characteristics of all-weather, long distance, large range, high resolution and the like, is developing towards the direction of multifunction, light weight and high reliability, and is one of indispensable information acquisition equipment in future unmanned combat scenes.
However, due to strict installation position and space limitations of the aerial platform, installation errors inevitably exist in the installation of the radar device and the aerial platform, the high-precision positioning and tracking of the radar system on a target are influenced, errors are calibrated and corrected when each set of equipment is installed, the maintenance time and cost of the aerial radar system can be greatly improved, the combat effectiveness of the equipment is reduced, and an efficient and convenient base-level internal field static calibration target calibration method needs to be provided urgently. Therefore, a static boresight method of the airborne radar system based on the POS is provided.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: how to solve the problems of long calibration and maintenance time, high cost, low combat effectiveness and the like of the installation error of the unmanned airborne radar system and the airborne platform, and provides a static target calibration method of the airborne radar system based on POS.
The invention solves the technical problems through the following technical scheme, and the invention comprises the following steps:
s1: a prism is arranged on an inertial measurement unit of the POS system, and the installation errors of the orientation posture of the prism X, Y, Z and the orientation posture of the inertial measurement unit X, Y, Z are calibrated;
s2: the normal direction of an antenna array surface of the radar system is controlled through the servo turntable, the radar is rotated in the azimuth direction by 360 degrees, and the initial zero control correction of the antenna is carried out;
s3: and adjusting the initial zero pointing angle of the antenna by measuring and calculating the error angle between the normal direction of the antenna array surface of the radar system and the X-axis direction when the prism on the inertia measurement unit is installed, until the calibration precision requirement is met, and realizing the static target calibration of the radar system in the internal field.
Furthermore, the radar system comprises an antenna unit, a servo turntable and a processing unit; the antenna unit is used for generating and radiating electromagnetic waves and receiving reflected electromagnetic wave signals; the servo turntable is used for controlling the pointing direction and the azimuth direction of the antenna unit to rotate for 360 degrees; the processing unit is used for processing signals and data, distributing remote control and remote measuring instructions and monitoring equipment states.
Further, in step S1, the POS system is installed inside the servo turntable, and includes an inertial measurement unit, a navigation solution module, and a satellite navigation antenna; the inertial measurement unit is used for measuring angular velocity and acceleration information of the radar, collecting real-time motion information of the airborne platform and providing the real-time motion information to the navigation resolving module; the navigation resolving module is used for performing real-time combination resolving by using the measurement value of the satellite navigation antenna and the measurement information of the inertial measurement unit to obtain the position, course, speed and attitude information of the airborne platform, and transmitting the position, course, speed and attitude information to the radar system in real time for storage and processing.
Further, in the step S1, the prism is a hexahedral prism, each surface of which is a plane, and two connected surfaces are perpendicular to each other.
Further, the specific process of step S1 is as follows:
s11: fixing an inertia measurement unit provided with a prism on a servo turntable, and measuring a north included angle between a normal line of the prism corresponding to a certain surface and a geographic coordinate system by using an auto-collimation theodolite, wherein the normal line of the surface is vertical to the X-axis direction of the inertia measurement unit;
s12: measuring a vertical angle between the normal lines of two adjacent vertical surfaces of the prism (which are in the same direction with the X axis of the IMU) and the horizontal plane of the geographic coordinate system by using the auto-collimation theodolite, and calculating to obtain an attitude angle in the direction of the prism X, Y, Z;
s13: acquiring an attitude angle of the initial position X, Y, Z direction by adopting a four-position method and an inertial measurement unit;
s14: and calibrating and correcting the installation error of the prism and the inertial measurement unit in the direction X, Y, Z by using the prism attitude angle and the inertial measurement unit attitude angle obtained by measurement and calculation and the mutual difference.
Further, in the step S12, the attitude angle θ between the prism carrier coordinate system and the geographic coordinate system is recorded according to the relative rotation relationship between the geographic coordinate system and the prism carrier coordinate system 0 ,γ 0 ,
Figure BDA0003657393060000021
Then:
Figure BDA0003657393060000022
wherein:
Figure BDA0003657393060000023
then there are:
Figure BDA0003657393060000024
according to the above formula, x b0 And y b0 Calculating x according to the projection relation of the axis in the geographic coordinate system b0 And y b0 The axes included the following angles to the geographic horizontal plane:
Figure BDA0003657393060000031
Figure BDA0003657393060000032
Figure BDA0003657393060000033
wherein, the angle alpha 1 and the angle alpha 2 are the elevation angles measured by the autocollimation theodolite;
the auto-collimation theodolite obtains a vertical included angle and a horizontal included angle between a vertical plane of the prism and a geographical horizontal plane through measurement by receiving collimated light reflected by the prism;
fixing the inertia measurement unit with the prism on an X, Y, Z triaxial rotary table, so that the ABCD surface of the prism points to the 0 degree direction of the triaxial rotary table, namely when the outer frame shaft of the triaxial rotary table points to the self scale ring by 0 degree, the mirror surface normal of the outer frame reflector of the triaxial rotary table coincides with the true north direction, the horizontal angle of the auto-collimation theodolite passing through the collimation outer frame reflector is less than phi 1, the horizontal angle of the auto-collimation theodolite re-collimation prism surface is less than phi 2, and the horizontal component of the prism surface normal and the north included angle of the geographic coordinate system are as follows:
Figure BDA0003657393060000034
assuming that the normal line and the hexahedral prism mirror y b0 If the axes are parallel, the north included angle between the normal horizontal component and the geographic coordinate system is:
Figure BDA0003657393060000035
obtaining the attitude angle theta of the prism in a certain measurement 0 ,γ 0 ,
Figure BDA0003657393060000036
And obtaining the attitude angle of the inertial measurement unit at the same time, namely obtaining the installation deviation angle of the prism and the inertial measurement unit.
Further, in the step S13, the specific process of the four-position method is as follows:
the angular velocity components of the course axis of the fiber-optic gyroscope are respectively measured at positions separated by 90 degrees by utilizing the IMU, namely omega 1 ，ω 2 ，ω 3 ，ω 4 The following formula is provided:
Figure BDA0003657393060000037
the following formulas are obtained:
Figure BDA0003657393060000038
finishing to obtain:
Figure BDA0003657393060000041
wherein θ is the course angle of the inertial measurement unit, and the horizontal attitude angle of the inertial measurement unit is calculated by the measurement value of the accelerometer, and the formula is as follows:
Figure BDA0003657393060000042
Figure BDA0003657393060000043
where phi is roll angle, gamma is pitch angle, A xg 、A yg The measurements of the accelerometers are x-axis and y-axis, respectively, and g is the acceleration of gravity.
Furthermore, in step S3, four points are marked with a cross target on the antenna array surface of the antenna unit as object points, the position of a cursor reflected by the autocollimation theodolite to the wall is marked as image points, X, Y, Z direction attitude values of the object points and the image points are respectively measured by using the autocollimation theodolite, and a deviation angle between a normal of a certain surface of the prism and a normal of the antenna array surface is obtained through processing and calculation, wherein the normal of the surface is perpendicular to the X-axis direction of the inertial measurement unit.
Compared with the prior art, the invention has the following advantages: when each set of equipment of the traditional unmanned airborne SARMTI reconnaissance monitoring radar is installed, installation errors need to be calibrated, so that the system maintenance time and the cost are high, and even the fighting efficiency of the equipment is reduced; the static target calibration method of the unmanned airborne radar system based on the POS efficiently and conveniently solves the problem, greatly saves the equipment maintenance time and cost, improves the maintainability and the combat effectiveness of equipment, and is worthy of being popularized and used.
Drawings
FIG. 1 is a schematic structural diagram of an unmanned airborne SARMTI surveillance radar system in an embodiment of the invention;
FIG. 2 is a schematic diagram of a POS system according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a radar system cross-linking with a POS device in an embodiment of the present invention;
FIG. 4a is a schematic view of a hexahedral prism structure according to an embodiment of the present invention;
FIG. 4b is a schematic view of the mounting of a hexahedral prism structure on an IMU according to an embodiment of the present invention;
fig. 5a is a schematic diagram of projection of ═ α 1 under X, Y, Z geographic coordinate system in the embodiment of the invention;
fig. 5b is a schematic diagram of projection of ═ α 2 under X, Y, Z geographic coordinate system in the embodiment of the invention;
FIG. 6a is a schematic diagram of a right normal component projection of a prism in an embodiment of the present invention;
fig. 6b is a schematic plan view of a X, Y, Z three-axis turret in an embodiment of the invention;
FIG. 7 is an axial schematic view of an IMU gyroscope according to an embodiment of the present invention;
FIG. 8 is a schematic representation of the cross-hair transfer of an antenna array prism in an embodiment of the present invention;
FIG. 9 is a schematic diagram of a layout of a "cross" target of a radar antenna array in an embodiment of the present invention;
FIG. 10 is a schematic diagram of a boresight process in an embodiment of the invention.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
As shown in fig. 1, which is a schematic structural diagram of the unmanned airborne SARMTI surveillance radar system according to the present invention, the unmanned airborne SARMTI surveillance radar system is installed on an unmanned aerial vehicle (airborne platform), and the system includes an antenna unit, a servo turntable (including a POS system), and a processing unit, wherein the antenna unit mainly functions to generate and radiate electromagnetic waves and receive reflected electromagnetic wave signals; the servo turntable is used for controlling the pointing direction and the azimuth direction of the antenna unit to rotate for 360 degrees; the processing unit is mainly used for performing functions of signal and data processing, remote control and remote measurement instruction distribution, equipment state monitoring and the like.
Fig. 2 is a schematic structural diagram of the integrated navigation, positioning and orientation system (POS system) of the present invention, and fig. 3 is a schematic cross-linking diagram of the radar system and the POS device in fig. 1.
The combined navigation positioning and orientation system (POS system) is installed in the servo turntable and comprises an Inertial Measurement Unit (IMU), a navigation resolving module (PCS) and a satellite navigation antenna. The power module of the radar system outputs +5V to supply power to the POS system, the satellite navigation antenna is used for receiving Beidou/GPS/GNSS satellite information in real time, the inertial measurement unit is used for measuring angular velocity and acceleration information of the radar, the real-time motion information of the aerial carrier platform is collected and provided to the navigation resolving module, the navigation resolving module utilizes the measurement value of the antenna receiver (the satellite navigation antenna) and the measurement information of the inertial measurement unit to carry out real-time combined resolving, the high-precision position, course, speed and attitude information of the aerial carrier platform is obtained, and the information is transmitted to the radar system in real time for storage and processing.
Fig. 4a is a schematic view showing a hexahedral prism structure, and fig. 4b is a schematic view showing an installation of the IMU and the hexahedral prism in the POS system shown in fig. 2.
Hexahedral prism ABCD-A 1 B 1 C 1 D 1 Each face of (2) all is a plane, and no matter where light shines from, the total reflection prism that uses when being different from the survey and drawing, the light of reflection all can parallel reflection go back:
1) wherein the face ABCD is approximately perpendicular to x of the IMU b Axis, denoted face 1;
2) side BB 1 C 1 Y with C approximately perpendicular to IMU b Axis, denoted face 2;
3) the perpendicularity between adjacent faces of the hexahedral prism is known to be within 2 "(strictly orthogonal perpendicularity);
4) the attitude angle of the hexahedral prism is three-axis A 1 A，A 1 B 1 ，A 1 D 1 The formed body coordinate system has three deviation angles relative to the geographic coordinate system.
The hexahedral prism and the IMU are fixedly installed through a designed installation bracket (the specific installation form is shown in figure 4 b), and the ABCD plane is vertical to the x of the IMU b And the axis needs to be subjected to installation error calibration, and the specific implementation method is illustrated in figures 5-7.
As shown in fig. 5a and 5b, the diagrams are respectively the projection diagrams of angle α 1 and angle α 2 under X, Y, Z geographic coordinate systems in the present invention. Wherein the X axial direction represents the east direction, the Y axial direction represents the sky direction, the Z axial direction represents the north direction, and the angle alpha 1 and the angle alpha 2 are prisms BB 1 C 1 C. The angle between the ABCD plane and the horizontal plane of the geographic coordinate system.
When the autocollimation theodolite is perpendicular to the hexahedron prism surface, it emits a light beam S 0 S 1 From perpendicular to S 0 S 1 When the hexahedron prism plane is reflected back to the autocollimation theodolite, the yellow cross can be seen in the autocollimation theodolite to coincide with the black cross in the autocollimation theodolite, at the moment, the optical axis is simultaneously vertical to the hexahedron prism surface and the autocollimation theodolite mirror surface, and the vertical angle alpha 1 rotated by the autocollimation theodolite is the surface BB 1 C 1 C included angle with geographical horizontal plane, also plane BB 1 C 1 The included angle between the normal AB of the C and the geographic horizontal plane is the included angle between a horizontal axis of the hexahedral prism carrier system and the horizontal plane of the geographic coordinate system; the other face is aligned in the same way.
According to the process of collimating the mirror surface of the prism by the auto-collimation theodolite, the included angle between two mutually perpendicular mirror surfaces of the prism and the horizontal plane of the geographic coordinate system can be obtained and recorded as ≈ α 1 and ≈ α 2, and simultaneously ≈ α 1 and ≈ α 2 are the included angle between two horizontal axes of a carrier system formed by hexahedral prisms and the horizontal plane of the geographic coordinate system.
Recording the hexahedral prism carrier system (ox) according to the relative rotation relationship between the geographic coordinate system and the hexahedral prism carrier system b0 y b0 z b0 Right front upper) and a geographical coordinate system at an attitude angle theta 0 ,γ 0 ,
Figure BDA0003657393060000061
Then:
Figure BDA0003657393060000062
wherein:
Figure BDA0003657393060000063
then there are:
Figure BDA0003657393060000064
according to formula (2), x b0 And y b0 The projection relation of the axis under the geographic coordinate system can be calculated to obtain x b0 And y b0 The included angles of the axes with the geographic horizontal plane are as follows:
Figure BDA0003657393060000065
Figure BDA0003657393060000066
Figure BDA0003657393060000071
in formula (3), angle α 1 and angle α 2 are the elevation angles measured by the auto-collimation theodolite.
The auto-collimation theodolite can measure and obtain a vertical included angle and a horizontal included angle between a vertical surface of the prism and a geographical horizontal plane by receiving collimated light reflected by the prism.
FIG. 6a is a schematic diagram of the right normal projection of the prism of the present invention; fig. 6b is a schematic plan view of X, Y, Z three-axis turret according to the present invention.
Fixing an inertia measurement unit provided with a hexahedral prism on an X, Y, Z three-axis turntable (three-axis turntable, for customizing measurement equipment), enabling the ABCD surface of the prism to point to the 0-degree direction of the three-axis turntable, namely when the outer frame shaft of the three-axis turntable points to the self scale ring for 0 degree, the normal line of the outer frame reflector of the three-axis turntable just coincides with the true north direction, the horizontal angle of an auto-collimation theodolite passing through the collimation outer frame reflector is phi 1, the horizontal angle of the auto-collimation theodolite re-collimation prism surface of the prism is phi 2, and the normal line of the prism surface at the moment (x-axis hexahedral prism carrier system x) is the normal line of the prism surface at the moment b0 Or y b0 Axis) and the north of the geographic coordinate system:
Figure BDA0003657393060000072
assuming that the normal line and the hexahedral prism mirror y b0 If the axes are parallel, the north included angle between the normal horizontal component and the geographic coordinate system is:
Figure BDA0003657393060000073
attitude angle θ of prism obtained according to equations (3) to (5) in a certain measurement 0 ,γ 0 ,
Figure BDA0003657393060000074
And obtaining the attitude angle of the IMU at the same time, namely obtaining the installation deviation angle of the prism and the IMU.
Fig. 7 is an axial schematic view of an IMU gyroscope according to the present invention.
The attitude angle of the IMU is obtained by calculation by adopting a four-position north-seeking method, and the specific principle of the four-position method is as follows:
the angular velocity components of the course axis of the fiber-optic gyroscope are respectively measured at positions separated by 90 degrees by utilizing the IMU, namely omega 1 ，ω 2 ，ω 3 ，ω 4 The following formula is given:
Figure BDA0003657393060000075
from the above equations, it follows:
Figure BDA0003657393060000076
finishing to obtain:
Figure BDA0003657393060000077
where θ is the heading angle of the IMU, and the horizontal attitude angle of the IMU can be calculated from the accelerometer measurements, as follows:
Figure BDA0003657393060000081
Figure BDA0003657393060000082
wherein φ is a roll angle, γ is a pitch angle, A xg 、A yg The measurements of the accelerometers are x-axis and y-axis, respectively, and g is the acceleration of gravity.
And directly carrying out difference according to the attitude value of the IMU obtained by the four-position method and the prism attitude value obtained by calibration calculation to obtain an installation error angle between the IMU and the prism, and carrying out error calibration.
Fig. 8 is a schematic view of the cross-hair between the antenna array and the prism of the present invention, and fig. 9 is a schematic view of the layout of the "cross" target of the radar antenna array of the present invention:
the method comprises the steps of installing an IMU with a prism on a servo turntable, marking four points on a radar antenna array surface by using a cross target as object points, marking the positions of the targets on a wall body by using a collimation theodolite through the prism as image points, respectively measuring X, Y, Z attitude values of the object points and the image points by using the collimation theodolite according to a four-position method, and obtaining a deviation angle between a normal line (the same direction as the X axis of the IMU) of one surface of the prism and a normal line of the antenna array surface through processing and calculation.
FIG. 10 is a flow chart of static zero calibration of the antenna installation based on POS according to the present invention.
According to the method, according to the flow of the steps, firstly, the mounting error between the IMU and the prism is calibrated, then, the zero-position error between the prism and the antenna array surface is calibrated, the mounting error between the IMU and the antenna array surface is calibrated through prism error transmission, and the system mounting accuracy is met after multiple measurements.
The unmanned aerial vehicle-mounted reconnaissance monitoring radar system adopts a two-dimensional active phased array + azimuth mechanical scanning system, and the unmanned aerial vehicle-mounted reconnaissance monitoring radar system comprises an antenna unit, a servo turntable and a processing unit, so that the hardware level is high, the unit composition is simple, and the volume and the weight of the system are reduced;
the radar system is provided with a combined navigation positioning and orientation system (POS system) of an MEMS (micro-electromechanical system), and comprises an Inertial Measurement Unit (IMU), a navigation resolving module (PCS), a satellite navigation antenna and other equipment, and outputs high-speed and high-precision position, course, speed and attitude information of an unmanned aerial vehicle platform in real time;
the invention uses the servo turntable to control the normal direction of the antenna array surface, and realizes the 360-degree rotation of the radar azimuth direction and the control and correction of the initial zero position (the direction of the aircraft nose) of the antenna;
the method adopts a four-position method, the prism is fixed on the IMU through the mounting bracket, the IMU is fixed on the servo turntable through the mounting hole position, and the accurate initial position X, Y, Z attitude value of the IMU is obtained by using the collimation theodolite for measurement; measuring and calculating the obtained prism attitude angle and IMU attitude angle, and calibrating and correcting the X and Y, Z direction installation errors of the prism and the IMU by the mutual difference;
the X axial direction of IMU installation is parallel to the normal direction of the antenna array surface, the collimation theodolite is used for measuring the object point and the image point X, Y, Z attitude value of the antenna array surface respectively, and the deviation angle between the normal of a certain surface of the prism (the same as the X axial direction of the IMU) and the normal of the antenna array surface is obtained through processing and calculation;
the calculation and control of the invention adopt software design, the measured deviation angle value is input through software, the servo turntable adjusts the normal direction of the antenna array surface, and the initial zero position (the direction of the machine head of the carrier) of the antenna array surface is corrected until the requirement of the calibration precision of the system is met.
In summary, when each set of equipment of the traditional unmanned airborne SARMTI reconnaissance surveillance radar is installed, installation errors need to be calibrated, so that the system maintenance time and the cost are high, and even the fighting efficiency of the equipment is reduced; the static target calibration method of the unmanned airborne radar system based on the POS of the embodiment efficiently and conveniently solves the problem, greatly saves the equipment maintenance time and cost, improves the maintainability and the combat effectiveness of equipment, and is worthy of being popularized and used.
Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (8)

1. A static boresight method of an airborne radar system based on POS is characterized by comprising the following steps:
s1: a prism is arranged on an inertial measurement unit of the POS system, and the installation errors of the orientation posture of the prism X, Y, Z and the orientation posture of the inertial measurement unit X, Y, Z are calibrated;
s2: the normal direction of an antenna array surface of the radar system is controlled through the servo turntable, the radar is rotated in the azimuth direction by 360 degrees, and the initial zero control correction of the antenna is carried out;
s3: and adjusting the initial zero pointing angle of the antenna by measuring and calculating the error angle between the normal direction of the antenna array surface of the radar system and the X-axis direction when the prism on the inertia measurement unit is installed, until the calibration precision requirement is met, and realizing the static target calibration of the radar system in the internal field.
2. The static boresight method of the POS-based airborne radar system as claimed in claim 1, wherein: the radar system comprises an antenna unit, a servo turntable and a processing unit; the antenna unit is used for generating and radiating electromagnetic waves and receiving reflected electromagnetic wave signals; the servo turntable is used for controlling the pointing direction and the azimuth direction of the antenna unit to rotate by 360 degrees; the processing unit is used for carrying out signal and data processing, remote control and remote measurement instruction distribution and equipment state monitoring.
3. The static boresight method of the POS-based airborne radar system according to claim 2, characterized in that: in step S1, the POS system is installed inside the servo turntable, and includes an inertial measurement unit, a navigation solution module, and a satellite navigation antenna; the inertial measurement unit is used for measuring angular velocity and acceleration information of the radar, collecting real-time motion information of the airborne platform and providing the real-time motion information to the navigation resolving module; the navigation resolving module is used for performing real-time combination resolving by using the measurement value of the satellite navigation antenna and the measurement information of the inertial measurement unit to obtain the position, course, speed and attitude information of the airborne platform, and transmitting the position, course, speed and attitude information to the radar system in real time for storage and processing.
4. The static boresight method of the POS-based airborne radar system according to claim 3, characterized in that: in the step S1, the prism is a hexahedral prism, each surface of which is a plane, and two connected surfaces are perpendicular to each other.
5. The static boresight method of the POS-based airborne radar system according to claim 4, characterized in that: the specific process of step S1 is as follows:
s11: fixing an inertia measurement unit provided with a prism on a servo turntable, and measuring a north included angle between a normal line of the prism corresponding to a certain surface and a geographic coordinate system by using an auto-collimation theodolite, wherein the normal line of the surface is vertical to the X-axis direction of the inertia measurement unit;
s12: measuring the vertical angle between the normal lines of two adjacent vertical surfaces of the prism and the horizontal plane of the geographic coordinate system by using an auto-collimation theodolite, and calculating to obtain the attitude angle of the prism X, Y, Z in the direction;
s13: acquiring an initial position X, Y, Z direction attitude angle by adopting a four-position method to acquire an inertial measurement unit;
s14: and calibrating and correcting the installation error of the prism and the inertial measurement unit in the direction X, Y, Z by using the prism attitude angle and the inertial measurement unit attitude angle obtained by measurement and calculation and the mutual difference.
6. The static boresight method of the POS-based airborne radar system according to claim 5, characterized in that: in step S12, the attitude angle between the prism carrier coordinate system and the geographical coordinate system is recorded as θ according to the relative rotation relationship between the geographical coordinate system and the prism carrier coordinate system 0 ,γ 0 ,
Figure FDA0003657393050000028
Then:
Figure FDA0003657393050000021
wherein:
Figure FDA0003657393050000022
then there are:
Figure FDA0003657393050000023
according to the above formula, x b0 And y b0 Calculating the projection relation of the axis in the geographic coordinate system to obtain x b0 And y b0 The included angles of the axes with the geographic horizontal plane are as follows:
Figure FDA0003657393050000024
Figure FDA0003657393050000025
Figure FDA0003657393050000026
wherein, the angle alpha 1 and the angle alpha 2 are the elevation angles measured by the autocollimation theodolite;
the auto-collimation theodolite obtains a vertical included angle and a horizontal included angle between a vertical plane of the prism and a geographical horizontal plane through measurement by receiving collimated light reflected by the prism;
fixing the inertia measurement unit with the prism on an X, Y, Z triaxial rotary table, so that the ABCD surface of the prism points to the 0 degree direction of the triaxial rotary table, namely when the outer frame shaft of the triaxial rotary table points to the self scale ring by 0 degree, the mirror surface normal of the outer frame reflector of the triaxial rotary table coincides with the true north direction, the horizontal angle of the auto-collimation theodolite passing through the collimation outer frame reflector is less than phi 1, the horizontal angle of the auto-collimation theodolite re-collimation prism surface is less than phi 2, and the horizontal component of the prism surface normal and the north included angle of the geographic coordinate system are as follows:
Figure FDA0003657393050000027
assuming that the normal line and the hexahedral prism mirror y b0 If the axes are parallel, the north included angle between the normal horizontal component and the geographic coordinate system is:
Figure FDA0003657393050000031
obtaining the attitude angle theta of the prism in a certain measurement 0 ,γ 0 ,
Figure FDA0003657393050000037
With attitude of inertial measurement unit obtained at the same timeAnd (4) obtaining the installation deviation angle of the prism and the inertial measurement unit.
7. The static boresight method of the POS-based airborne radar system according to claim 6, characterized in that: in step S13, the specific procedure of the four-position method is as follows:
the fiber-optic gyroscope of the inertia measurement unit is used for measuring angular velocity components of the course axis at positions which are separated by 90 degrees, namely omega 1 ，ω 2 ，ω 3 ，ω 4 The following formula is given:
Figure FDA0003657393050000032
the following formulas are obtained:
Figure FDA0003657393050000033
finishing to obtain:
Figure FDA0003657393050000034
wherein θ is the course angle of the inertial measurement unit, and the horizontal attitude angle of the inertial measurement unit is calculated by the measurement value of the accelerometer, and the formula is as follows:
Figure FDA0003657393050000035
Figure FDA0003657393050000036
where phi is roll angle, gamma is pitch angle, A xg 、A yg The measurements of the accelerometers are x-axis and y-axis, respectively, and g is the acceleration of gravity.
8. The static boresight method of the POS-based airborne radar system according to claim 7, characterized in that: in step S3, four points are marked with a cross target on the antenna array surface of the antenna unit as object points, the autocollimation theodolite is reflected to the wall by the prism to mark a cursor position as an image point, the autocollimation theodolite is used to measure the X, Y, Z attitude angles of the object points and the image points, respectively, and the deviation angle between the normal of a certain surface of the prism and the normal of the antenna array surface is obtained through processing and calculation, and the normal of the surface is perpendicular to the X-axis direction of the inertia measurement unit.
CN202210564654.1A 2022-05-23 2022-05-23 Static boresight method of airborne radar system based on POS Pending CN114994622A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210564654.1A CN114994622A (en) 2022-05-23 2022-05-23 Static boresight method of airborne radar system based on POS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210564654.1A CN114994622A (en) 2022-05-23 2022-05-23 Static boresight method of airborne radar system based on POS

Publications (1)

Publication Number Publication Date
CN114994622A true CN114994622A (en) 2022-09-02

Family

ID=83027193

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210564654.1A Pending CN114994622A (en) 2022-05-23 2022-05-23 Static boresight method of airborne radar system based on POS

Country Status (1)

Country Link
CN (1) CN114994622A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114325607A (en) * 2021-11-25 2022-04-12 中国电子科技集团公司第三十八研究所 Sea detection function equivalent assessment test method for airborne radar
CN114325607B (en) * 2021-11-25 2024-05-14 中国电子科技集团公司第三十八研究所 Equivalent assessment test method for sea detection function of airborne radar

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114325607A (en) * 2021-11-25 2022-04-12 中国电子科技集团公司第三十八研究所 Sea detection function equivalent assessment test method for airborne radar
CN114325607B (en) * 2021-11-25 2024-05-14 中国电子科技集团公司第三十八研究所 Equivalent assessment test method for sea detection function of airborne radar

Similar Documents

Publication Publication Date Title
US9194954B2 (en) Method for geo-referencing an imaged area
US6208937B1 (en) Method and apparatus for generating navigation data
CN113311436B (en) Method for correcting wind measurement of motion attitude of laser wind measuring radar on mobile platform
KR101809294B1 (en) Method and system of determining spatial orientation information of a body from multiple electromagnetic signals
US6784840B2 (en) Method for determining azimuth and elevation angles using a single axis direction finding system
CN106500731B (en) A kind of Calibration Method of the boat-carrying theodolite based on fixed star simulation system
KR100860767B1 (en) Apparatus and method for digital mapping manufacture using airborne laser surveying data
CN105549060A (en) Object positioning system based on position and attitude of airborne photoelectric gondola
US5463402A (en) Motion measurement system and method for airborne platform
CN110926468A (en) Communication-in-motion antenna multi-platform navigation attitude determination method based on transfer alignment
CN103323855A (en) Method for obtaining accuracy of reference line dynamic measurement system
CN110297220B (en) Method for measuring baseline vector of dual-antenna InSAR system
CN111366913A (en) Calibration method for optical axis pointing measurement error of satellite-borne laser radar
US6594582B1 (en) GPS compound eye attitude and navigation sensor and method
RU2303229C1 (en) Method for formation of stabilization and homing signal of movable carrier and on-board homing system for its realization
CN110220533A (en) A kind of onboard electro-optical pod misalignment scaling method based on Transfer Alignment
CN106602263A (en) Strapdown-type high-precision stabilized platform system built based on integrated navigation
CN109470274B (en) Vehicle-mounted photoelectric theodolite vehicle-mounted platform deformation measurement system and method
RU2723199C1 (en) Method and system for determining orientation of spacecraft in space with autonomous correction of light aberration effect
CN107807375B (en) Unmanned aerial vehicle attitude tracking method and system based on multiple GPS receivers
Li et al. Airborne position and orientation system for aerial remote sensing
CN114994622A (en) Static boresight method of airborne radar system based on POS
Kim Motion measurement for high-accuracy real-time airborne SAR
US11015758B2 (en) Gimbal radial counterbalance systems and methods
CN111380563A (en) Detection device, photoelectric theodolite detection system and aviation airborne optical platform detection system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination