Removing atmospheric MTF and establishing an MTF compensation filter for the HJ-1A CCD camera
Removing atmospheric MTF and establishing an MTF compensation filter for the HJ-1A CCD camera
复制标题
HJ-1A CCD相机去除大气MTF并建立MTF补偿滤波器
DOI：
10.1080/01431161.2012.721020
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发表时间：
2013-02
影响因子：
3.4
通讯作者：
Li Liu
中科院分区：
文献类型：
--
作者：
Xiaoying Li;Xingfa Gu;Qiaoyan Fu;Tao yu;Hailiang Gao;Jiaguo Li;Li Liu
总的图像调制传递函数（MTF）包括成像系统的MTF和大气的MTF，这两个都可以产生模糊效应的遥感图像。成像系统MTF是成像系统的重要指标之一，用来表征传感器的辐射响应。大气调制传递函数包括气溶胶调制传递函数和湍流调制传递函数，通常随外界大气条件变化而变化。为了获得成像系统的MTF，必须从总的图像MTF中去除大气MTF。研究了环境一号A星CCD相机大气调制传递函数的消除方法。首先利用暗目标反演的气溶胶光学厚度（AOD）和NCEP/NCAR的再分析资料，对CCD图像中的气溶胶MTF和湍流MTF进行了预测。然后，通过从CCD图像上的线性特征计算的总在轨图像MTF中去除气溶胶和湍流的MTF来恢复CCD相机的MTF。结果表明，对于HJ-1A CCD相机，去除大气调制传递函数后，奈奎斯特频率下的调制传递函数值增加了约10%。当AOD值较大或湍流较强时，图像的MTF会下降约50%。此外，本研究建立了一个调制传递函数补偿（MTFC）滤波器的HJ-1A通过修改的“修正逆滤波器（MIF）”的方法。实验结果表明，该模型的有效瞬时视场（EIFOV）从78 m提高到41 m，同时模型的噪声水平得到了很好的控制。这项研究表明，修改后的方法是有效的传感器与低MTF值。
The total image modulation transfer function (MTF) comprises imaging system MTF and atmospheric MTF, both of which can produce blurring effects in remote-sensing images. Imaging system MTF, one of the important specifications of the imaging system, is used to characterize the radiometric response of the sensor. Atmospheric MTF, which consists of aerosol MTF and turbulence MTF, usually changes with external atmospheric conditions. To obtain the MTF of the imaging system, the atmospheric MTF has to be removed from the total image MTF. This study aims to determine a method for removing the atmospheric MTF for the charge-coupled device (CCD) camera on-board the Huanjing 1A satellite (HJ-1A). The aerosol MTF and the turbulence MTF in the CCD images were first predicted based on the aerosol optical depth (AOD) derived by dark target and reanalysis of data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). Then, the MTFs of the CCD camera were retrieved by removing the aerosol and turbulence MTFs from the total on-orbit image MTFs that were calculated from the linear features on CCD images. For the HJ-1A CCD camera, results show that the MTF values at Nyquist frequency increased by about 10% after the atmospheric MTFs were removed. The total image MTF became degraded by about 50% when AOD was high or turbulence was strong. Furthermore, this study has established an MTF compensation (MTFC) filter for the HJ-1A by modifying the ‘modified inverse filter (MIF)’ approach. Results illustrate that the effective instantaneous field of view (EIFOV) of the restored image improved from 78 to 41 m, while the noise level of the model was well controlled. This research demonstrates that the modified approach is effective for sensors with low MTF values.
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影响因子：
1.9
作者：
C. Coulman;J. Vernin;Y. Coqueugniot;J. Caccia
通讯作者：
C. Coulman;J. Vernin;Y. Coqueugniot;J. Caccia
影响因子：
1.9
作者：
N. Kopeika
通讯作者：
N. Kopeika
DOI：
10.1364/josaa.15.003097
发表时间：
1998-12
影响因子：
1.9
作者：
N. Kopeika;I. Dror;D. Sadot
通讯作者：
N. Kopeika;I. Dror;D. Sadot
影响因子：
1.3
作者：
Y. Yitzhaky;I. Dror;N. Kopeika
通讯作者：
Y. Yitzhaky;I. Dror;N. Kopeika
DOI：
10.1117/12.280598
发表时间：
1997-08
期刊：
--
影响因子：
--
作者：
R. Richter
通讯作者：
R. Richter