基于物方一致性的珞珈三号01星视频数据在轨实时稳像

Object-Space-Consistency-Based Real-Time Stabilization Approach for Luojia3-01 Video Data

利用高分辨率敏捷光学卫星的凝视观测能力,对特定区域或目标进行连续观测,从而实现区域监测、目标跟踪等应用,是高分辨率光学卫星的应用热点之一。获取的凝视观测数据经过几何与稳像处理后,能得到稳定的高质量视频数据。但受制于过程中需要的大量运算,星载设备计算与存储能力难以满足,该处理只能由地面系统在事后完成,信息获取的时效性低。针对该问题,基于珞珈三号01星数据特点与星载硬件计算能力,提出一种基于物方一致性的在轨视频帧实时稳像方法。所提方法利用实时几何定位,在卫星成像过程中实时提取并对目标区域影像进行几何校正;同时利用影像帧之间地理信息的一致性,对相邻影像帧进行实时配准,保证帧间相对精度;在此基础上,通过构建算法并行流水线,实时生成带有地理编码的兴趣区视频帧序列。使用珞珈三号01星真实数据与帧率(6帧/s)进行实验,结果表明,基于珞珈三号01星嵌入式星载处理硬件,所提方法能够实现快于6帧/s的处理速度,同时获得的视频帧序列带有地理编码,且帧间稳像精度达0.328像素,可满足星载实时服务需求。

Objectives High-resolution agile optical satellites can continuously observe specific regions or targets,thereby realizing applications such as regional monitoring and target tracking.In order to obtain stable and high-quality video data,continuous observation data need to be geographically corrected and stabilized.This process requires a large amount of calculation,but the on-board computing and storage device cannot meet the demand.Therefore,this process can only be completed afterwards by on-ground system,resulting in a significant delay in information acquisition.Methods This paper proposes an object-space-consistency-based real-time stabilization approach for Luojia3-01 satellite video data,which is based on data characteristics and computing capability of embedded on-board hardware.The proposed approach employs real-time geometric positioning to extract and correct the region of interest(ROI)in real-time during satellite imaging.Additionally,it employs the consistency of geographical information in real-time align adjacent image frames to ensure the relative accuracy between sequence frames.On the basis,it generates a sequence of video frames of ROI with geographical encoding in real-time through the construction of a parallel pipeline of algorithms.Results The experiments are conducted by the actual data of Luojia3-01 satellite with the frame rate of 6 frame per second,and the proposed approach can realize the faster processing based on the embedded on-board processing hardware.Furthermore,the obtained video frame sequence with geographic encoding and the inter-frame stabilized accuracy is better than 0.328 pixels.Conclusions The proposed approach can meet the requirements of on-board real-time service.