In-orbit calibration method of star sensor lens distortion and satellite attitude determination method based on starlight vector correction

A technology of lens distortion and star sensor, which is applied in the field of satellite attitude determination, can solve the problems of low precision and inability to calibrate the lens temperature distortion term of the star sensor, and achieves the effect of eliminating satellite attitude determination errors.

CN103234556AInactive Publication Date: 2013-08-07HARBIN INST OF TECH
2 Cites 19 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2013-08-07
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention relates to an in-orbit calibration method of star sensor lens distortion and a satellite attitude determination method based on starlight vector correction. The invention relates to an in-orbit calibration method of star sensor lens distortion and a satellite attitude determination method. The invention aims at solving a problem of incapability of calibrating a temperature distortion term of an existing calibration method, and a problem of low precision of an existing satellite attitude determination. The star sensor lens distortion in-orbit calibration method comprises the steps that: an included angle between fixed star incident light and a lens optical axis is obtained by calculation according to target fixed star imaging point coordinates and a star sensor lens distortion formula; a light vector direction of the target fixed light is obtained according to the included angle of the incident light and the lens optical axis; and in-orbit calibration of star sensor lens distortion is carried out according to a principle that the included angles of light vector directions of a plurality of target fixed stars are fixed. The attitude determination method comprises the steps that: a target fixed star starlight vector is obtained by calculation according to the target fixed star imaging point coordinates and the star sensor lens distortion formula obtained by calibration; and satellite attitude is determined through star map matching. The methods provided by the invention are applied in the technical field of satellite attitude determination.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of satellite attitude determination, in particular to a method for on-orbit calibration of star sensor lens distortion based on starlight vector correction and a satellite attitude determination method. Background technique

[0002] Among various satellite attitude sensors, star sensors have the highest attitude determination accuracy. With the further exploration of space, higher requirements are placed on satellite attitude determination and control accuracy. Therefore, star sensors are used in satellite attitude determination. The system is used more and more. The star sensor lens will produce serious lens distortion after working for a long time in the harsh space working environment. In addition, the drastic change of ambient temperature in space will cause real-time changes in the degree of distortion of the star sensor lens. However, the existing star sensor lens distortion calibration method cannot ...

Examples

specific Embodiment approach 1

[0040] Embodiment 1: The present invention corrects multiple star sensor lens distortions including temperature distortion coefficients by using the principle of equal star angle distance, and the method for on-orbit calibration of star sensor lens distortion based on starlight vector correction is carried out in the following steps :

[0041] Step 1. Calculate the derivative of the measured star angle distance between the i-th target star and the j-th target star to the lens distortion coefficient, the specific expression is as follows, where a is the lens distortion coefficient, x i 、x j 、y i 、y j are the x and y coordinates of the imaging points of the i-th target star and the j-th target star respectively, α i 、α j are the angles between the incident light of the i-th target star and the j-th target star and the optical axis of the lens,

[0042] ∂ ∂ a W i T ...

specific Embodiment approach 2

[0056] Specific implementation mode two: the present invention introduces a lens distortion model in the process of determining the target star starlight vector by the coordinates of the star sensor imaging point, and its process is shown in the appendix figure 1 , the satellite attitude determination method based on star sensor lens distortion proceeds in the following steps:

[0057] Step 1. The star sensor images the target star to obtain the coordinates (x, y, f) of the imaging point in the star sensor coordinate system, where x and y are the coordinates of the imaging point in the x and y directions respectively, and f is the star sensor The focal length of the device lens; the angle β between the outgoing light of the lens and the optical axis of the lens is obtained from the coordinates of the imaging point, and the specific calculation formula is:

[0058] β = arccos f x 2 ...