The Experts below are selected from a list of 24330 Experts worldwide ranked by ideXlab platform
Ting Sun - One of the best experts on this subject based on the ideXlab platform.
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an accuracy Measurement method for star trackers based on direct astronomic observation
Scientific Reports, 2016Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu Wang, Daping ChuAbstract:Star tracker is one of the most promising optical Attitude Measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy Measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy Measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the Measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental Measurements confirm that this method is effective and convenient to implement. Such a Measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.
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smearing model and restoration of star image under conditions of variable angular velocity and long exposure time
Optics Express, 2014Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu WangAbstract:The star tracker is one of the most promising Attitude Measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.
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optical system error analysis and calibration method of high accuracy star trackers
Sensors, 2013Co-Authors: Ting Sun, Fei Xing, Zheng YouAbstract:The star tracker is a high-accuracy Attitude Measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and Measurement of high-accuracy star trackers.
Zheng You - One of the best experts on this subject based on the ideXlab platform.
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an accuracy Measurement method for star trackers based on direct astronomic observation
Scientific Reports, 2016Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu Wang, Daping ChuAbstract:Star tracker is one of the most promising optical Attitude Measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy Measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy Measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the Measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental Measurements confirm that this method is effective and convenient to implement. Such a Measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.
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smearing model and restoration of star image under conditions of variable angular velocity and long exposure time
Optics Express, 2014Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu WangAbstract:The star tracker is one of the most promising Attitude Measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.
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optical system error analysis and calibration method of high accuracy star trackers
Sensors, 2013Co-Authors: Ting Sun, Fei Xing, Zheng YouAbstract:The star tracker is a high-accuracy Attitude Measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and Measurement of high-accuracy star trackers.
Fei Xing - One of the best experts on this subject based on the ideXlab platform.
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an accuracy Measurement method for star trackers based on direct astronomic observation
Scientific Reports, 2016Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu Wang, Daping ChuAbstract:Star tracker is one of the most promising optical Attitude Measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy Measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy Measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the Measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental Measurements confirm that this method is effective and convenient to implement. Such a Measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.
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smearing model and restoration of star image under conditions of variable angular velocity and long exposure time
Optics Express, 2014Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu WangAbstract:The star tracker is one of the most promising Attitude Measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.
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optical system error analysis and calibration method of high accuracy star trackers
Sensors, 2013Co-Authors: Ting Sun, Fei Xing, Zheng YouAbstract:The star tracker is a high-accuracy Attitude Measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and Measurement of high-accuracy star trackers.
Xiaochu Wang - One of the best experts on this subject based on the ideXlab platform.
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an accuracy Measurement method for star trackers based on direct astronomic observation
Scientific Reports, 2016Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu Wang, Daping ChuAbstract:Star tracker is one of the most promising optical Attitude Measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy Measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy Measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the Measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental Measurements confirm that this method is effective and convenient to implement. Such a Measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.
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smearing model and restoration of star image under conditions of variable angular velocity and long exposure time
Optics Express, 2014Co-Authors: Ting Sun, Fei Xing, Zheng You, Xiaochu WangAbstract:The star tracker is one of the most promising Attitude Measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.
Jie Li - One of the best experts on this subject based on the ideXlab platform.
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Attitude Measurement based on imaging ray tracking model and orthographic projection with iteration algorithm
Isa Transactions, 2019Co-Authors: Jun Tang, Jie Li, Chong ShenAbstract:Abstract In the field of vision-based Attitude estimation, camera model and Attitude solving algorithm are the key technologies, which determine the Measurement accuracy, effectiveness and applicability. Aiming at this issue, in this paper we probe into the generic imaging model and then develop a corresponding generic camera calibration method using two auxiliary calibration planes. The camera model is named as imaging ray tracking model. Based on the imaging ray tracking camera model and with the knowledge of the calibration parameters, an advanced Attitude solving algorithm, imaging ray tracking model and Attitude from orthographic projection with iterations algorithm, is deeply investigated, which is inspired by the classical POSIT algorithm. The initial Attitude value is provided by the orthographic projection of the object on the two calibration planes and then refined by iteration to approximate the true object Attitude. Experimental platform is setup to conduct the imaging ray tracking camera calibration procedure and further evaluate our Attitude estimation algorithm. We show the effectiveness and superiority of our proposed Attitude estimation algorithm by thorough testing on real-data and by comparison with the POSIT algorithm.
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Attitude measuring method adapted to high speed rotary body
2010Co-Authors: Yongfeng Ren, Jie Li, Yunbo Shi, Wei Yang, Jijun Xiong, Wendong Zhang, Guoying Liu, Tao Guo, Guoyong Zeng, Liu JunAbstract:The invention is the Attitude Measurement method for the high-speed revolving solid. It can be proper for the axial high-speed revolving solid. It installs the three accelerometers of Ax, Ay and Az which the gauging spindle is coincidence with the vertical axis, the cross axis and the vertical axis; also it installs two speed gyroscopes of Gy and Gz which the gauging spindle is coincidence with the cross axis and the vertical axis. The assistant accelerometer A'y which the gauging spindle is coincidence with the negative direction of the cross axis is installed in the carrier. The angular velocity Omegax of the high-speed revolving solid vertical axis is computed by the above expression, the next Attitude and navigation resolving are finished by the theory and the method in the strapdown inertial navigation equipment.
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semi strapdown type Attitude measuring method adapted to high speed rotary body
2007Co-Authors: Wendong Zhang, Jie Li, Yongfeng Ren, Yunbo Shi, Wei Yang, Jijun Xiong, Liu Jun, Jinming Li, Wenyi Liu, Tao GuoAbstract:The invention is a semi-strapdown Attitude Measurement method for the high-speed revolving solid. It can be proper for the axial high-speed revolving solid. It installs the inertial navigation system in the carrier which the inside wall is fixed with the rigid supporter. The rolling bearing is supported on the supporter which supports the rotating shaft whose axes is in the same direction with the rolling axis of the carrier coordinate. The inertial navigation system is connected in one end of the rotating shaft and the other is the stud and the heavy punch which is the same direction with the pitch axis of the carrier coordinate. So it can be used for measuring the Attitude of the high-speed revolving solid by the present MEMS inertial sense organ-speed gyroscope.
