航空相机动态调制传递函数分析与研究

影像位移是影响航空相机分辨率的主要因素。用MTF对动态成像质量做出评价，确立合理的稳定系统性能指标，是设计过程中常用的手段。为此研究了匀速运动，变速运动和正弦运动条件下的动态MTF，针对目前无法准确评价的低频正弦运动，提出了基于离散相位区间的动态MTF计算方法。分析结果表明，在像模糊斑大小相同的情况下，高频振动对像质的破坏最严重，直线运动次之，低频振动最轻。根据所作分析可以针对给定的影像位移计算出相应的动态MTF，为航空相机像质评价提供了准确定量的参考。

LIAO Jing-yu1,2,GAO Xiao-dong1,LIANG Wei1

 Using Modulation Transfer Function(MTF) method to evaluate image quality and establish reasonable stabilization system performance standard,is a serious problem during the design process.Based on transfer function theory of linear optical system,dynamic image process during uniform,accelerated and sinusoidal motions were studied and numerically analyzed.The relationship between image motion and dynamic image quality was established.And a new method based on discrete phase intervals was especially developed to evaluate low frequency sinusoid motion.The analysis and results indicate that with the same image blur of 0.5 pixel,MTFs of high frequency sinusoid motion,linear motion and low frequency motion can respectively reach 0.85,0.9 and 0.998,to obtain good dynamic images.The conclusion was made that high frequency vibration damages the image quality most,linear motion less and low frequency does the least.According to analysis given,dynamic MTF can be solved for a certain image motion,to offer quantitative reference for the image evaluation of aerial camera.