TDI CCD全景航空相机前向像移补偿的DSP实现

航空相机拍照的过程中沿着飞行的方向，景物与感光介质之间存在着相对运动，此种运动称为前向像移。为了提高航空相机的照相分辨率，必须对该像移进行补偿，从而以使景物与感光介质在拍照的过程中相对静止。本文首先分析了TDI CCD(Time Delay and Integration Charge-Coupled Devices)全景航空相机前向像移的产生原因，像移补偿精度与伺服系统指标之间的关系，以及补偿机构－反射镜的工作方式，然后提出了一种基于定点DSP(Digital Signal Processing)芯片的像移补偿控制系统，将前向像移的补偿算法用DSP芯片实时实现。本文深入讨论了DSP伺服控制系统中的补偿精度、算法选择、相位计算、时间约束等关键问题，最后给出了一种适合于工程实际的硬件结构与软件流程。

Research On Forward Motion Compensation In Panoramic Aerial Camera With TDI CCD Based On DSP

It will inevitably bring motion, which is called forward motion, to aerial images due to relative movement between scenes and sensitive medium. In order to improve aerial image resolutions, the motions must be compensated, so the scene and sensitive medium will keep relative stillness when photographing. First, this paper analyzes causes of image forward motions, relationships between compensation precision and requirements for servo control system, and operations of compensation structure-scanning mirror, then proposes a novel kind of forward motion compensation system using DSP chip, which implements control algorithm digitally. Meanwhile this paper also discusses some critical issues, such as compensation precision, algorithms selection, phase calculation and time constrains in servo control system when using DSP. Finally this paper describes hardware architecture and software flow chart suiting for engineering.