嫦娥四号动力下降段图像可视化传输方案

针对嫦娥四号降落相机在动力下降段的图像可视化传输需求和深空通信下行数传信道带宽受限的矛盾，文章提出了一种动力下降段速率自适应的可视化图像传输方案，对如何保证降落相机图像下传的实时性、完整性、速率自适应性等关键问题进行了讨论，并对方案中涉及的抽帧回放算法、帧格式识别方法、合路调度算法等关键技术进行了详细说明。同时，文中给出了该方案在嫦娥四号在轨的验证情况，结果表明，在数传通信速率受限的情况下该方案实现了降落相机图像的存储管理和可视化下传，具有实时性高、速率自适应、图像下传完整等特点，可以为其他航天器数据管理系统设计提供参考。

Visual Image Transmission Scheme of Chang’E-4 Powered Descending Phase

In view of the contradiction between the visual image transmission demand of Chang’E 4 landing camera (LCAM) in the powered descending phase and the limited bandwidth of the transmission channel in deep space communications, a visual image transmission scheme is proposed in this paper. The key issues such as real time, integrity and adaptive rate are discussed. The key technologies, such as frame extraction, playback algorithm, frame format identification method, and joint scheduling algorithm, are described in detail. At the same time, the verification of the scheme onboard Chang’E 4 is given in the paper. The results show that the storage management and visual download of the LCAM images under the condition of the limited data communications rate are realized, with the characteristics of good real time, rate adaptation and image integrity, providing reference for the design of spacecraft data management systems.