高行频混合域TDI累加成像技术研究  

Research on Mixing Domain TDI Accumulation Imaging Technology with High Line Frequency

作　　者：梁楠[1] 贺强民[1] 李博[1] 李涛[1] LIANG Nan;HE Qiangmin;LI Bo;LI Tao(Beijing Institute of Space Mechanics&Electricity,Beijing 100094,China)

机构地区：[1]北京空间机电研究所,北京100094

出　　处：《航天返回与遥感》2020年第1期39-46,共8页Spacecraft Recovery & Remote Sensing

基　　金：航天五院杰出青年人才基金。

摘　　要：随着航天遥感领域高分辨率时间延迟积分成像中行频的提高,在一个积分时间内入瞳能量逐渐减少,在弱光条件下成像品质下降,需要采用增大积分级数的方法弥补能量的不足。现有传统数字域累加势必会导致叠加引入过多噪声,而模拟域又受到器件工艺的影响无法实现大级数累加。文章首先提出了一种基于电荷域和数字域混合的累加方式,并阐述了具体成像方案。同时,结合相机在轨成像方式,对混合域累加方式下的信噪比和调制传递函数(Modulation Transfer Function,MTF)进行了理论推导。文章最后搭建实验环境对混合域累加方式下信噪比和MTF进行测试,并与传统电荷域进行比较,验证了混合域累加理论的正确性以及实现方法的可行性。根据分析与验证,文章所提方法有效的解决了单纯电荷域与数字域的主要瓶颈,为超高分辨率成像领域提供了有效的解决方案。With the increase of the line frequency in high-resolution Time Delay Integration(TDI)imaging in the field of space remote sensing,the camera's input energy is gradually reduced in one integration time,and the camera's imaging ability is reduced under weak illumination.It is necessary to increase the integral number to compensate for the lack of energy.The existed traditional digital domain accumulation methods will inevitably lead to excessive noise introduced by the superposition,and the analog domain is affected by the device process and cannot achieve large-scale accumulation.This paper first proposes an accumulation method based on the mixture of charge domain and digital domain,and describes the specific imaging scheme.At the same time,the paper makes a theoretical analysis on the signal noise ratio(SNR)and modulation transfer function(MTF)in the mixed domain accumulation mode combining with the on-orbit imaging mode of the camera.Finally,the experimental environment is built to test the SNR and MTF in the mixed domain accumulation mode.compared with the traditional charge domain,the correctness of the mixed domain accumulation theory and the feasibility of the implementation method are verified.According to the analysis and verification results,the proposed method effectively solves the main bottleneck in charge domain and digital domain TDI,and provides an effective solution in the high resolution field.

关 键 词：高分辨率 混合域时间延迟积分 信噪比 调制传递函数 航天遥感 

分 类 号：TN401[电子电信—微电子学与固体电子学]