CN-115932906-B - On-orbit calibration method for multi-antenna phase center of satellite-borne navigation receiver

CN115932906BCN 115932906 BCN115932906 BCN 115932906BCN-115932906-B

Abstract

The invention provides a multi-antenna phase center on-orbit calibration method of a satellite-borne navigation receiver, which comprises the steps of S1, selecting an on-orbit rough measurement target antenna from antennas to be calibrated, adjusting the gesture of a satellite platform, enabling a reference antenna and the on-orbit rough measurement target antenna to deviate to the direction of a finger, S2, resolving to generate an RTK rough measurement vector, acquiring original measurement data by the satellite platform, S3, downloading on-orbit measurement information of the on-orbit rough measurement target antenna to a ground station, S4, repeating the steps S1-S3, traversing all the antennas to be calibrated, S5, carrying out off-line processing by the ground station based on the on-orbit measurement information, resolving phase center position deviation of each antenna to be calibrated, and S6, uploading the satellite platform to complete on-orbit calibration. The invention utilizes the on-orbit differential positioning of the double antennas and the real-time satellite attitude measurement information, and can effectively avoid the influence of the multipath effect of the ground environment by means of post ground processing and uploading, thereby solving the technical problem that the absolute phase center cannot be accurately calibrated after the satellite mounting of the multiple antennas.

Inventors

AI QI
LU SHAN
LI HUIXIONG
ZHU YUMENG
ZHANG XIAOTONG

Assignees

上海航天控制技术研究所

Dates

Publication Date: 20260508
Application Date: 20221221

Claims (7)

1. An on-orbit calibration method for a multi-antenna phase center of a satellite-borne navigation receiver, wherein the satellite-borne navigation receiver is arranged on a satellite platform, the satellite platform also comprises a navigation receiving antenna which is electrically connected with the satellite-borne navigation receiver, the navigation receiving antenna comprises 1 reference antenna and a plurality of antennas to be calibrated, and the on-orbit calibration method is used for on-orbit calibrating the relative phase centers of the antennas to be calibrated and the reference antenna by taking the phase center of the reference antenna as a reference; the satellite platform can be communicated with a ground station and is characterized by comprising the following steps: S1, selecting an on-orbit rough measurement target antenna from the antennas to be calibrated, and adjusting the gesture of the satellite platform to enable the reference antenna and the on-orbit rough measurement target antenna to deviate to the direction of a finger antenna, so that the reference antenna and the on-orbit rough measurement target antenna have enough common-view satellites; S2, based on the reference antenna and the on-orbit rough measurement target antenna, the satellite-borne navigation receiver carries out calculation according to a double-antenna RTK technology to generate an RTK rough measurement vector of the on-orbit rough measurement target antenna; S3, taking the generated RTK rough measurement vector of the on-orbit rough measurement target antenna, the acquired original measurement data of the reference antenna and the on-orbit rough measurement target antenna, ephemeris information, satellite platform attitude information and reference antenna absolute position information as on-orbit measurement information of the on-orbit rough measurement target antenna, and downloading the on-orbit measurement information of the on-orbit rough measurement target antenna to the ground station; S4, repeating the steps S1-S3 until all the antennas to be calibrated are traversed; s5, the ground station performs off-line processing based on-orbit measurement information of each antenna to be calibrated, and calculates phase center position deviation of each antenna to be calibrated relative to a reference antenna; S6, uploading the phase center position deviation of each antenna to be calibrated to a satellite platform in a parameter uploading mode, and completing on-orbit calibration.
2. The on-orbit calibration method according to claim 1, wherein step S5 comprises: S51, selecting a ground optimization target antenna from the antennas to be calibrated, performing post-optimization processing on RTK rough measurement vectors of the ground optimization target antenna according to a dual-antenna RTK technology based on-orbit measurement information of the ground optimization target antenna, and removing outlier smoothing to obtain a ground-based fixed system accurate measurement vector S52, based on the observation data issued by the IERS at regular intervals, calculating and obtaining a conversion matrix from a fixed system to an inertial system at the UTC moment of a certain epoch according to an IAU 2000A/B time difference nutation model S53, on-orbit measurement information and ground fixation accurate measurement vector of the ground optimization target antenna Conversion matrix from ground-fixed system to inertial system Calculating the vector of the ground optimization target antenna relative to the reference antenna under the body coordinate system The solution formula is as follows: Wherein, the The gyroscope attitude in the satellite platform attitude information in the in-orbit measurement information is obtained by measuring a satellite platform attitude sensor; S54, based on the reference antenna absolute position information in the on-orbit measurement information of the ground optimization target antenna and the vector of the ground optimization target antenna relative to the reference antenna under the body coordinate system Calculating the phase center position deviation of the ground optimization target antenna relative to a reference antenna; and S55, repeating the steps S51-S54 until all the antennas to be calibrated are traversed.
3. The on-orbit calibration method according to claim 2, wherein the calculation formula of step S52 is: Wherein W (t), R (t) and Q (t) are respectively a polar motion matrix, an earth rotation matrix and a time difference nutation conversion matrix, and t is a time variable; further, the calculation formula of the polar-shift matrix W (t) in the formula (1) is as follows: W(t)=R z (-s′)R y (x p )R x (y p ); (2) s′=0.047mas×t; The polar motion x p 、y p is regularly published by the ier according to astronomical observation, and R x (θ)、R y (θ)、R z (theta) is a transformation matrix in the process of coordinate system transformation, as follows: further, the calculation formula of the earth rotation matrix R (t) in the formula (1) is as follows: Wherein, the Available in fortran source programs provided by ies for earth self-rotation angle; further, the calculation formula of the time lapse nutation matrix Q (t) in the formula (1) is as follows: wherein α=1/2+1/8 (X 2 +Y 2 ), formula (4) (X, Y) = (X, Y) IAU2000 +(dX,dY) IERS , wherein (X, Y) IAU2000 and s can be solved according to the fortran source program provided by the ier, and (dX, dY) IERS is a correction term of the high-frequency motion of the ground axis, and is periodically published by the ier according to astronomical observation.
4. The method of on-orbit calibration as claimed in claim 1, wherein said biasing the reference antenna and the on-orbit rough target antenna toward the direction of the reference antenna in step S1 means, The first included angle between the axis direction of the reference antenna and the direction opposite to the geocentric vector is equal to the second included angle between the axis direction of the on-orbit rough measurement target antenna and the direction opposite to the geocentric vector, and the first included angle and the second included angle are smaller than or equal to 90 degrees.
5. The on-orbit calibration method according to claim 1, wherein the RTK rough measurement vector of the on-orbit rough measurement target antenna is an under-ground-fixed-system RTK result vector of the on-orbit rough measurement target antenna which is not optimized with respect to the reference antenna.
6. The on-orbit calibration method according to claim 1, wherein the raw measurement data comprises pseudorange, carrier phase, doppler data.
7. The method of on-orbit calibration according to claim 1, wherein the satellite platform attitude information is a satellite platform attitude quaternion of the body system relative to the inertial system at each epoch.

Description

On-orbit calibration method for multi-antenna phase center of satellite-borne navigation receiver Technical Field The invention relates to a navigation receiver multi-antenna fusion RTK (carrier phase measurement) technology, in particular to an on-orbit calibration method for a satellite-borne navigation receiver multi-antenna phase center. Background With the wide application of various GNSS (global navigation satellite system) such as beidou, GPS (global positioning system) and the like, a navigation receiver becomes a main sensor for absolute and relative navigation of satellites. The method is limited by the navigation positioning principle of GNSS, and continuous high-precision navigation measurement is needed to be realized by means of a multi-antenna fusion RTK technology when a satellite platform is frequently maneuvered in posture. RTK is millimeter-scale measurement method taking antenna phase center position as reference, for formation satellite system with on-orbit frequent attitude maneuver, based on the characteristic of conventional antenna near hemispherical coverage pattern, navigation receiver is often required to configure multiple antennas in different quadrants and different orientations to perform multiple antenna fusion RTK. The antenna phase center is the center of curvature of a curve where the equiphase plane of the far-zone radiation field intersects with a plane passing through the antenna axis, i.e., the center of the radiation source where the antenna radiates electromagnetic waves equivalently. At present, three methods of simulation calculation, darkroom measurement and receiver system test are available for calibrating the antenna phase center. The simulation calculation method cannot accurately evaluate the distortion, the darkroom measurement method has high requirements on measurement sites, is generally suitable for small-volume independent antennas, is too large in size and is not suitable for satellite navigation receiver systems with multiple antennas after satellite installation, and the receiver system test method is affected by multipath effects of the ground environment, so that the calibration accuracy is poor. Disclosure of Invention The invention aims to provide an on-orbit calibration method for a multi-antenna phase center of a satellite-borne navigation receiver, which utilizes double-antenna on-orbit differential positioning to combine real-time satellite attitude measurement information, can effectively avoid the influence of multipath effect of ground environment by means of post ground processing and uploading, and solves the problem that the absolute phase center cannot be accurately calibrated after the multi-antenna satellite mounting. In order to achieve the above purpose, the present invention is realized by the following technical scheme: the on-orbit calibration method for the multi-antenna phase center of the satellite-borne navigation receiver is characterized in that the satellite-borne navigation receiver is arranged on a satellite platform, the satellite platform further comprises a navigation receiving antenna electrically connected with the satellite-borne navigation receiver, the navigation receiving antenna comprises 1 reference antenna and a plurality of antennas to be calibrated, the on-orbit calibration method is used for calibrating the relative phase center of each antenna to be calibrated and the reference antenna on the basis of the phase center of the reference antenna, and the satellite platform can communicate with a ground station, and comprises the following steps: S1, selecting an on-orbit rough measurement target antenna from the antennas to be calibrated, and adjusting the gesture of the satellite platform to enable the reference antenna and the on-orbit rough measurement target antenna to deviate to the direction of a finger antenna, so that the reference antenna and the on-orbit rough measurement target antenna have enough common-view satellites; S2, based on the reference antenna and the on-orbit rough measurement target antenna, the satellite-borne navigation receiver carries out calculation according to a double-antenna RTK technology to generate an RTK rough measurement vector of the on-orbit rough measurement target antenna; S3, taking the generated RTK rough measurement vector of the on-orbit rough measurement target antenna, the acquired original measurement data of the reference antenna and the on-orbit rough measurement target antenna, ephemeris information, satellite platform attitude information and reference antenna absolute position information as on-orbit measurement information of the on-orbit rough measurement target antenna, and downloading the on-orbit measurement information of the on-orbit rough measurement target antenna to the ground station; S4, repeating the steps S1-S3 until all the antennas to be calibrated are traversed; s5, the ground station performs off-line processing based on-orbit measure