Geometric external calibration method for the airborne large-view-field infrared scanner considering different effects of left and right pendulum directions
Geometric external calibration method for the airborne large-view-field infrared scanner considering different effects of left and right pendulum directions
An airborne pendulum large-view-field infrared scanner has the advantages of large view field and high-resolution images.However,it may be affected by various factors during sensor installation,transportation,and flight,which may cause the position centers and angles of the sensor and the POS system to be changed.Therefore,geometric calibration must be performed to improve the geometric quality of the images acquired by the sensor.Furthermore,this scanner produces left-pendulum and right-pendulum images,respectively,during the flight.Moreover,the left-pendulum and right-pendulum images have different imaging integration directions,which may cause different influence on imaging quality.Therefore,this study presents an external geometric calibration method considering different influences of the different pendulum directions.By considering different influences of the different pendulum directions of this airborne pendulum large-view-field infrared scanner,a geometric external calibration model is introduced,and it is characterized by the following:(1)The installation errors of the sensor and POS are considered.Moreover,the left-and right-pendulum images are used to calculate the installation parameters.Especially,different calibration parameters are used for the right-and left-pendulum images.The aim is to compensate for the different influences caused by different imaging integration directions.(2)Furthermore,calibration parameters for the installation errors of the sensor and POS are regarded as pseudo-observations because the installation errors of the sensor and POS are generally small.By regarding the calibration parameters as the pseudo-observations,the calibration model can avoid large unreasonable estimated parameters.The proposed method is applied in the calibration of the images collected by this airborne pendulum large-view-field infrared scanner.Experimental results show that the calibration model can effectively improve the geometric positioning accuracy of the images.The absolute average back-projection residuals of the control points in the left-and right-pendulum images are improved to be subpixel level.
维普
万方数据