AI 中文总结
针对地球观测卫星重访周期延迟问题，提出Stride框架，利用轨道重访特性和图像时间冗余，通过云指示器、参考选择器和变化检测器等组件，提升了重访图像传输分数、降低延迟并扩大覆盖范围，性能达最优。
AI 中文摘要
通常，地球观测卫星遵循重访周期规则，按固定间隔定期飞越地球同一区域，由轨道特性和仪器特性共同决定。但在卫星下行链路带宽有限时，会出现重访周期延迟，即只能传输部分图像，推迟完整数据集的时效性。本文提出用于地球观测的重访感知在轨边缘计算框架Stride。它利用轨道重访特性提供历史参考重访图像，利用重访图像的时间冗余仅传输感兴趣区域。Stride包括单时相和多时相云指示器、粗到精的参考选择器和集成局部变化检测器。在Flat - Sat试验台和星座模拟器上的实验表明，Stride将重访图像传输（RID）分数提高了4.55倍，降低连接延迟5.02倍，扩大映射覆盖范围2.56倍，性能达到最优。
英文摘要
Typically, Earth observation satellites follow a rule of revisiting cycle to periodically pass over the same area of the Earth at regular intervals, which is jointly determined by their orbital properties (e.g., eccentricity, inclination) and instrument characteristics (e.g., off-nadir pointing and swath capabilities). However, we have observed delays in perceived revisiting cycles where limited satellite downlink bandwidth allows only partial images to be delivered, pushing back the timeliness of the full set of data, which we term as revisiting cycle delay. In this paper, we present a revisiting-aware in-orbit edge computing framework for Earth observation termed Stride. Stride leverages the unique orbital revisiting properties to afford historical reference revisiting images onboard, and exploits the inherent temporal redundancy in the revisiting imagery to transmit only the Regions of Interest (RoIs). Specifically, Stride comprises a mono- and multi-temporal cloud indicator to alleviate cloud contamination, a coarse-to-fine reference selector for orbit deviation correction, and an ensemble-local change detector to address inter-band complexities and pixel-level perturbations. Experiments on a Flat-Sat testbed and a constellation simulator demonstrate Stride improves the Revisiting Imagery Delivery (RID) score by up to 4.55X, decreases the connectivity latency by 5.02X, and enlarges the mapping coverage by 2.56X, yielding state-of-the-art performance.
