光学成像载荷空间分辨率的球面靶标直接检测法  

Direct Detection Method for Spatial Resolution of Optical Imaging Loads Based on Spherical Target

作　　者：纪松[1] 张永生[1] 李凯 范大昭[1] 杨伟铭 Ji Song;Zhang Yongsheng;Li Kai;Fan Dazhao;Yang Weiming(Institute of Geospatial Information,Information Engineering University,Zhengzhou 450001,Henan,China;Institute of System Engineering,Academy of Military Sciences,Beijing 100044,China)

机构地区：[1]信息工程大学地理空间信息学院,河南郑州450001 [2]军事科学院系统科学研究院,北京100044

出　　处：《光学学报》2023年第18期270-285,共16页Acta Optica Sinica

基　　金：国家自然科学基金(41971427);高分遥感测绘应用示范系统(二期)(42-Y30B04-9001-19/21);嵩山实验室项目(纳入河南省重大科技专项管理体系)(221100211000-4);遥感与空间智能系统中原学者首席科学家工作室专项(2018007)

摘　　要：空间分辨率是衡量遥感载荷光学成像性能的重要指标。传统二维扇形靶标影像难以直接用于载荷空间分辨率检测,精度受限于载荷构像模型以及影像校正处理方法。本文结合圆球球面数学模型,设计了扇形与网格混合的球面靶标,提出了一种直接在球面靶标影像上进行光学成像载荷空间分辨率检测方法。该方法针对球面同心圆移动椭圆成像以及偏心率局部一致特点,沿球面同心圆圆心直线方向进行多尺度椭圆拟合,并通过多尺度拟合椭圆长半轴的相对比例关系来精确计算遥感载荷空间分辨率,达到直接基于球面靶标中心投影影像进行载荷空间分辨率检测的效果。采用仿真球面靶标进行检测方法准确性验证,实验结果表明,本文方法具有优于传统检测方法的检测精度。进一步采用中国(嵩山)卫星遥感定标场中布设的实体球面靶标,开展了光学成像载荷空间分辨率检测实验,验证了本文方法的空间分辨率直接检测能力和检测结果有效性。Objective In the context of intelligent surveying and mapping,the quality of remote sensing imagery directly determines the intelligent interpretation level,the accuracy of image products,and ability of application services.Before processing and application,effective evaluation of remote sensing imagery or payload is required.Spatial resolution is an important index to measure the imaging performance of optical remote sensing payload,which is usually detected by three-bar targets or fan-shaped targets deployed in the remote sensing calibration.The three-bar detection method features simplicity and directness.However,due to discrete deployment,the detection results are easily affected by the phase difference factor,with low accuracy of the method.Fan-shaped targets are usually deployed on a two-dimensional plane.Due to the influence of perspective imaging and geometric distortion,the spatial resolution detection method should be carried out under the condition of vertical photography or geometric correction.Thus,during imaging at a large angle,the method cannot be directly employed for resolution detection due to large geometric deformation.Even under the condition of geometric correction,the resolution detection accuracy will be greatly reduced due to edge reduction or pixel mixing effect.Therefore,according to the isotropic characteristics of the three-dimensional spherical surface,this paper proposes to construct a fan-shaped resolution detection target on a spherical surface,which is called a spherical target.It also hopes that the spherical target can be helpful in solving the problems brought by three-bar or fan-shaped radial targets,and can be directly adopted for spatial resolution detection of high-resolution optical imaging loads under non-vertical imaging and nongeometric correction conditions.Methods Firstly,this paper builds a mathematical model of the spherical target and analyzes the design modes of the spherical target under equal and unequal conditions,with deployment strategies of spherical targe

关 键 词：扇形靶标 球面靶标 光学成像载荷 空间分辨率 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]