Calibration method for equivalent extinction ratio of polarized pixel in integrated micropolarizer array camera

Author(s):  
Bin Feng ◽  
Zelin Shi ◽  
Haizheng Liu ◽  
Yaohong Zhao ◽  
Jianting Liu
2016 ◽  
Vol 45 (6) ◽  
pp. 612003 ◽  
Author(s):  
吴培 WU Pei ◽  
王延杰 WANG Yan-jie ◽  
孙宏海 SUN Hong-hai ◽  
姚志军 YAO Zhi-jun ◽  
武治国 WU Zhi-guo

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3779
Author(s):  
Haonan Ren ◽  
Jian Yang ◽  
Xin Liu ◽  
Panpan Huang ◽  
Lei Guo

The performance of camera-based polarization sensors largely depends on the estimated model parameters obtained through calibration. Limited by manufacturing processes, the low extinction ratio and inconsistency of the polarizer can reduce the measurement accuracy of the sensor. To account for the challenges, one extinction ratio coefficient was introduced into the calibration model to unify the light intensity of two orthogonal channels. Since the introduced extinction ratio coefficient is associated with degree of polarization (DOP), a new calibration method considering both azimuth of polarization (AOP) error and DOP error for the bionic camera-based polarization sensor was proposed to improve the accuracy of the calibration model parameter estimation. To evaluate the performance of the proposed camera-based polarization calibration model using the new calibration method, both indoor and outdoor calibration experiments were carried out. It was found that the new calibration method for the proposed calibration model could achieve desirable performance in terms of stability and robustness of the calculated AOP and DOP values.


Author(s):  
Wei Liu ◽  
Fangming Qian ◽  
Yuzhe Miao ◽  
Rongjian Wang

At present, the on-orbit calibration of the geometric parameters of a space surveying camera is usually processed by data from a ground calibration field after capturing the images. The entire process is very complicated and lengthy and cannot monitor and calibrate the geometric parameters in real time. On the basis of a large number of on-orbit calibrations, we found that owing to the influence of many factors, e.g., weather, it is often difficult to capture images of the ground calibration field. Thus, regular calibration using field data cannot be ensured. This article proposes a real time self-calibration method for a space linear array camera on a satellite using the optical auto collimation principle. A collimating light source and small matrix array CCD devices are installed inside the load system of the satellite; these use the same light path as the linear array camera. We can extract the location changes of the cross marks in the matrix array CCD to determine the real-time variations in the focal length and angle parameters of the linear array camera. The on-orbit status of the camera is rapidly obtained using this method. On one hand, the camera’s change regulation can be mastered accurately and the camera’s attitude can be adjusted in a timely manner to ensure optimal photography; in contrast, self-calibration of the camera aboard the satellite can be realized quickly, which improves the efficiency and reliability of photogrammetric processing.


Author(s):  
Wei Liu ◽  
Fangming Qian ◽  
Yuzhe Miao ◽  
Rongjian Wang

At present, the on-orbit calibration of the geometric parameters of a space surveying camera is usually processed by data from a ground calibration field after capturing the images. The entire process is very complicated and lengthy and cannot monitor and calibrate the geometric parameters in real time. On the basis of a large number of on-orbit calibrations, we found that owing to the influence of many factors, e.g., weather, it is often difficult to capture images of the ground calibration field. Thus, regular calibration using field data cannot be ensured. This article proposes a real time self-calibration method for a space linear array camera on a satellite using the optical auto collimation principle. A collimating light source and small matrix array CCD devices are installed inside the load system of the satellite; these use the same light path as the linear array camera. We can extract the location changes of the cross marks in the matrix array CCD to determine the real-time variations in the focal length and angle parameters of the linear array camera. The on-orbit status of the camera is rapidly obtained using this method. On one hand, the camera’s change regulation can be mastered accurately and the camera’s attitude can be adjusted in a timely manner to ensure optimal photography; in contrast, self-calibration of the camera aboard the satellite can be realized quickly, which improves the efficiency and reliability of photogrammetric processing.


2009 ◽  
Vol 29 (4) ◽  
pp. 982-986
Author(s):  
Jun ZHANG ◽  
Bang-ping WANG ◽  
Cheng YI ◽  
Xiao-feng LI ◽  
Hui LI

2013 ◽  
Vol 34 (7) ◽  
pp. 1558-1561 ◽  
Author(s):  
Gui-bao Wang ◽  
Hai-hong Tao ◽  
Lan-mei Wang

ROBOT ◽  
2013 ◽  
Vol 35 (5) ◽  
pp. 600 ◽  
Author(s):  
Wenbin GAO ◽  
Hongguang WANG ◽  
Yong JIANG ◽  
Xin'an PAN

ROBOT ◽  
2013 ◽  
Vol 35 (5) ◽  
pp. 521
Author(s):  
Feng WANG ◽  
Kai CHEN ◽  
Xiaoping CHEN

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