Multispectral registration method based on stellar trajectory fitting

Liu, Yan; Yang, Lin; Chen, Fansheng

doi:10.1007/s11082-018-1458-4

Cited by 13 publications

(3 citation statements)

References 16 publications

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“…Theoretically, the trajectory should be a smooth curve. However, affected by the disturbance of satellite platform, the instability of the pointing mirror, and error in discrete sampling, the actual trajectory generally presents as a series of irregular scattered points [ 45 ], which results in a centroid position error and affects the subsequent positioning accuracy. Therefore, in order to improve the accuracy of the star’s position, a smoothing spline is adopted to fitting the trajectory of the scattered star imaging points.…”

Section: Methodsmentioning

confidence: 99%

On-Orbit Geometric Calibration from the Relative Motion of Stars for Geostationary Cameras

Jiang

et al. 2021

Sensors

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Affected by the vibrations and thermal shocks during launch and the orbit penetration process, the geometric positioning model of the remote sensing cameras measured on the ground will generate a displacement, affecting the geometric accuracy of imagery and requiring recalibration. Conventional methods adopt the ground control points (GCPs) or stars as references for on-orbit geometric calibration. However, inescapable cloud coverage and discontented extraction algorithms make it extremely difficult to collect sufficient high-precision GCPs for modifying the misalignment of the camera, especially for geostationary satellites. Additionally, the number of the observed stars is very likely to be inadequate for calibrating the relative installations of the camera. In terms of the problems above, we propose a novel on-orbit geometric calibration method using the relative motion of stars for geostationary cameras. First, a geometric calibration model is constructed based on the optical system structure. Then, we analyze the relative motion transformation of the observed stars. The stellar trajectory and the auxiliary ephemeris are used to obtain the corresponding object vector for correcting the associated calibration parameters iteratively. Experimental results evaluated on the data of a geostationary experiment satellite demonstrate that the positioning errors corrected by this proposed method can be within ±2.35 pixels. This approach is able to effectively calibrate the camera and improve the positioning accuracy, which avoids the influence of cloud cover and overcomes the great dependence on the number of the observed stars.

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Section: Methodsmentioning

confidence: 99%

On-Orbit Geometric Calibration from the Relative Motion of Stars for Geostationary Cameras

Jiang

et al. 2021

Sensors

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“…The complete transformation from the image coordinate system of ði; jÞ to the geocentric geodetic coordinate system (GGCS) of (latitude, longitude) can be expressed by Eqs. (1)- (5) as follows: E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 1 ; 1 1 6 ; 6 9 9…”

Section: Rigorous Imaging Modelmentioning

confidence: 99%

“…3 The characteristics of the sensors, distortions of the optical system, alignment matrix from the instrument to the satellite, attitude derived from star trackers and gyros, and the satellite position and velocity vectors play a significant role in determining the navigation accuracy of satellites. [4][5][6] In addition, suffering from the spatial thermal elastic deformation, the geometric positioning model of geostationary satellites changes greatly, 1,2,7 which inevitably has a bad effect on the positioning accuracy. Hence, an efficient method for promoting navigation accuracy is very important for geostationary satellites.…”

Section: Introductionmentioning

confidence: 99%

On-orbit installation matrix calibration and its application on AGRI of FY-4A

Chen

Zhang

et al. 2020

J. Appl. Rem. Sens.

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Image navigation is a primary process for on-orbit optical payloads involving environmental disaster monitoring, meteorological observation, and the positioning and tracking of space-aeronautics targets. However, because they are affected by solar illumination and orbital heat flux, as well as shock and vibration during launch, the installation structures between the instruments and satellite platform, especially for geostationary satellites, will inevitably generate a displacement resulting in the reduction of positioning accuracy. During the application of FengYun-4A (FY-4A), it is found that the further away from the subsatellite point, the greater the positioning error of Advanced Geostationary Radiation Imager (AGRI) on FY-4A will be. The positioning error can reach 14 pixels at the Arabian Peninsula in operational images. In addition, compared with orbital and attitude measurement errors, long-term observations show that the installation matrix is likely to be the most significant factor determining the navigation accuracy of AGRI. Therefore, an on-orbit installation matrix calibration approach as well as a high-precision navigation algorithm is proposed to modify the positioning error of AGRI. Experimental results show that the navigation error of the processed images corrected by the proposed method can be reduced to 1.3 pixels, which greatly improves the navigation procession of AGRI. In general, this method could be a supplement to the correction of positioning error for geostationary payloads.

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