摘要
合成孔径雷达(SAR)能够不受天气、时间影响地获取高分辨率图像,因此,被广泛用于测绘、灾害监测、环境监测、资源侦察等领域。由于SAR是侧视成像,在复杂的地形中雷达波束会被障碍物遮挡,从而形成叠掩和阴影,这样不仅会造成数据的缺失,而且会加重后续对数据处理的工作负担。针对以上问题,在进行无人机航线规划时,通常要保证相邻航带的重叠率来减少叠掩和阴影对图像质量的影响。为了在减少重叠率的同时保证高质量的成像,研究了考虑地形起伏的SAR测绘航线规划问题,将旁向重叠度、覆盖率和叠掩阴影率作为评价指标,提出了基于模拟退火算法的机载SAR测绘航线规划方法,并展开仿真实验对提出的方法进行验证。实验结果表明:所提出的方法能够将航带的旁向重叠度均控制在设定值以内,并使覆盖率达到90%以上;航线数量相比以平均高度面为基准设计航线的方法降低了31.21%,测区覆盖率相比完全不考虑地形的航线设计方法提高了84.80%;相比Greedy算法,其几何形变率降低了8.73%,其冗余航线数量减少了100%。
Synthetic Aperture Radar(SAR)can obtain high-resolution images regardless of the influence of weather and time;therefore,it is widely used in mapping,disaster monitoring,environmental monitoring,resource reconnais⁃sance,etc.Due to the side-view imaging of SAR,the radar beam will be blocked by obstacles in some complex ter⁃rains,resulting in layover and shadow.This will not only cause data missing but also aggravate the workload of subse⁃quent data processing.To address the above problems,it is usually necessary to ensure the overlap ratio of adjacent flight swaths to reduce the influence of layover and shadow on image quality when planning the path of the Unmanned Aerial Vehicle(UAV)-borne SAR.To reduce the overlap ratio while ensuring high-quality images,this paper studies the SAR mapping path planning problem considering terrains.Taking the lateral overlap ratio,coverage ratio,and overlap ratio as evaluation targets,a UAV-borne SAR mapping path planning method is proposed based on simulated annealing.Simulation experiments are carried out to verify the proposed method.The experimental results show that the method proposed can control the lateral overlap ratio of flight swath within the set value,and make the coverage ratio reach more than 90%.The number of paths decreased by 31.21%compared with that of the method based on the average altitude plane,and the coverage ratio of test area increased by 84.8%compared with that of the method without considering the terrain.The geometric deformation ratio and the number of redundant paths are also reduced by 8.73%and 100%respectively compared with that of the Greedy algorithm.
作者
肖友刚
满香娜
伍国华
罗启章
XIAO Yougang;MAN Xiangna;WU Guohua;LUO Qizhang(College of Traffic and Transportation Engineering,Central South University,Changsha 410073,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2023年第17期213-229,共17页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(62073341)。
关键词
区域覆盖
航线设计
无人机测绘
机载SAR
地形起伏
模拟退火
area coverage
path planning
UAV surveying and mapping
UAV-borne SAR
terains
simulated annealing