航天TDICCD相机谱间串扰分析与处理

Spectral Crosstalk Analyzing and Processing for Aerospace TDICCD Camera

摘要:

为了提高航天TDICCD遥感相机信噪比和成像质量,对TDICCD遥感相机成像谱段间相互串扰进行了深入研究。在高密TDICCD成像电路设计过程中,由于PCB电路板空间有限,布局布线密集,导致信号间隔离度差,引起谱段间信号相互串扰。这种串扰的存在严重影响各个谱段有效信号的采集,当各谱段工作频率不同时,图像即产生明显的串扰条纹。本文首先根据信号处理流程介绍了成像系统的组成,给出两种串扰现象；然后,分析串扰产生原因及其边界条件,并给出成像串扰抑制的方案。最后,对改进后的TDICCD成像系统进行成像和信噪比测试。实验结果表明,采取的措施有效地去除了TDICCD成像谱间串扰条纹,相机信噪比得到了显著的提高,在相机辐亮度为133.729W/(m2*Sr)的条件下,相机信噪比提高了6.92dB,达到了47.83dB,满足实际工程的需求。

Abstract:

In order to improve the signal-to-noise ratio and imaging quality of aerospace TDICCD remote sensing cameras, in-depth research was conducted on the crosstalk between the imaging spectral bands of TDICCD remote sensing cameras. In the design process of high-density TDICCD imaging circuits, due to the limited space and dense layout and wiring of PCB circuit boards, the isolation between signals is poor, resulting in crosstalk between spectral bands of signals. The existence of this kind of crosstalk seriously affects the collection of effective signals in various spectral bands. When the working frequencies of each spectral band are different, the image generates obvious crosstalk stripes. This article first introduces the composition of the imaging system based on the signal processing process, and provides two types of crosstalk phenomena; Then, analyze the causes of crosstalk and its boundary conditions, and provide a solution for suppressing imaging crosstalk. Finally, conduct imaging and signal-to-noise ratio testing on the improved TDICCD imaging system. The experimental results show that the measures taken effectively remove the crosstalk stripe between TDICCD imaging spectra bands, and the camera signal-to-noise ratio has been significantly improved. Under the condition of camera radiance of 133.729W/(m2 * Sr), the camera signal-to-noise ratio has increased by 6.92dB, reaching 47.83dB, meeting the needs of practical engineering.