GPS拒止条件下的景象匹配导航方法研究  

Research on scene matching navigation method under GPS-denied environments

作　　者：李家松 李明磊 魏大洲 李威 吴伯春[2] Li Jiasong;Li Minglei;Wei Dazhou;Li Wei;Wu Bochun(College of Electronic and Information Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;China Aeronautical Radio Electronics Research Institute,Shanghai 200233,China)

机构地区：[1]南京航空航天大学电子信息工程学院,江苏南京210016 [2]中国航空无线电电子研究所,上海200233

出　　处：《电子技术应用》2022年第3期88-93,共6页Application of Electronic Technique

基　　金：南京航空航天大学研究生创新基地开放基金(kfjj20200413);国家自然科学基金(41801342);中央高校基本科研业务费专项资金(NZ2020008)。

摘　　要：提出了一种在GPS拒止条件下使用视觉词袋辅助航空景象匹配导航的方法。在景象匹配导航任务中,基准地图比空中探测的图像具有更大的覆盖范围,当基准地图有大量相似或重复纹理特征出现时,仅依靠特征匹配难以得出正确的对应关系。首先对基准卫星影像地图进行区块划片,并利用视觉词袋技术对每一片区块进行编码,利用统计特性计算局部区块特征矢量,即区块特征直方图;然后,对空中探测图像使用同一词袋进行编码,用于从大量候选区块中筛选出初始对应区块;最后,使用尺度不变特征进行精配准并计算飞行器相对位置。实验使用了直升机拍摄的空中影像与高清卫星影像中提取的基准地图进行实验分析,并与先进技术进行比较,结果表明该方法具有良好的匹配可靠性和配准精度,能够在GPS拒止条件下为基于景象匹配的航空飞行器定位需求提供支持。This paper presents a visual word-based method for scene-matching aided navigation,which can work under GPS-denied environment.Since the reference satellite images may have many similarities and repetitive textures,it is difficult to initialize the correct correspondences between the reference satellite images and the aerial images only by feature matching.The paper proposes a bag of visual word(BOVW)based method to find the initial corresponding region.First,the reference satellite image is divided into blocks and encoded each block by BOVW model to generate a feature vector,namely block feature histogram.Then,the aerial images are encoded with the same model for screening the initial region from a large collection of blocks.Finally,the scale-invariant features are used to refine registration and calculate the accuracy position.In this paper,the aerial images taken by helicopters and the reference maps extracted from high-resolution satellite images are used for experimental analysis,and the performance is validated by extensive comparisons to state-of-the-art techniques.The experimental results show that the proposed method has good matching reliability and registration accuracy,and can provide support for aircraft positioning requirements based on scene-matching under GPS-denied environment.

关 键 词：视觉词袋 飞行器定位 景象匹配 区块匹配 图像配准 

分 类 号：TN967.2[电子电信—信号与信息处理]