宽视场遥感相机像移速度模型及补偿策略

宽视场遥感相机在轨成像期间,受地球自转、卫星颤振、姿态机动等因素影响而产生像移,导致成像质量降低。为此,提出了一种适用于宽视场遥感相机的像移速度模型,并考虑了离轴角对计算精度的影响,推导了离轴三反相机像移速度和偏流角解析式。以某卫星为例,仿真分析了3种典型成像模式下像移速度和偏流角在焦面的分布情况,仿真结果与定性分析结果一致,验证了像移速度模型的正确性。在此基础上,针对侧摆兼具俯仰成像模式,提出了相应的像移补偿策略。补偿效果表明,卫星侧摆35°兼具俯仰35°成像时,采用全局优化偏流角匹配策略能保证整个焦面区域的调制传递函数（modulation transfer function,MTF）均大于0.95（16级）;采用局部优化偏流角匹配策略能保证焦面重点观测目标的MTF大于0.95（96级）;采用提出的像移速度匹配策略在分11组调节行周期情况下,能保证整个焦面区域的MTF均大于0.95（16级）。仿真结果表明,提出的像移补偿策略能有效解决侧摆兼具俯仰成像时的像质下降问题,可为宽视场遥感相机像移补偿提供可靠依据。     

空间CCD相机的高速多通道图像高可靠光纤传输系统

为了提高空间CCD相机中数字视频图像信息的传输带宽,增强图像传输抗电磁干扰能力并提高光纤链路的整体性能,开发了应用于大视场空间相机的数字视频图像信息高可靠光纤传输系统。首先,根据CCD成像单元特点和相机在轨工作环境得出了传输系统的输入速率,在此基础上并结合CCD视频处理结构设计并实现了9通道CCD图像数据光纤并行传输系统。然后,阐述了系统设计思想,并说明了高速串化器和光模块的设计理念。接着,提出了(16,8)纠错编码算法,阐述了该算法思想和实现电路。最后,在XX-X空间多光谱相机样机的传输系统上进行了试验验证。实验结果表明:该传输系统图像传输正确、工作稳定、可靠性高、实时强、无误码,单路有效数据率达到2.44Gbit/s。(16,8)纠错编码算法纠错能力强、易于硬件实现、占用资源少。纠错算法在3043Byte内可以纠正191bit错误。该传输系统满足了空间相机图像传输的要求。     

Spatial pattern reconstruction of regional habitat quality based on the simulation of land use changes from 1975 to 2010

Reconstruction of the spatial pattern of regional habitat quality can revivify the ecological environment background at certain historical periods and provide scientific support for revealing the evolution of regional ecological environmental quality.In this study,we selected 10 driving factors of land use changes,including elevation,slope,aspect,GDP,population,temperature,precipitation,river distance,urban distance,and coastline distance,to construct the CA-Markov model parameters and acquired the land use spatial data for 1975,1980,1985,1990,and 1995 by simulation based on the land use status map for 2010.On this basis,we used the InVEST model to reconstruct the spatial pattern of habitat quality in the study area and conducted classification division and statistical analysis on the computed habitat degradation degree index and the habitat quality index.(1)The results showed that from 1975 to 2010,the habitat degradation degree gradually increased,and the habitat degradation grade spatially presented a layered progressive distribution.Habitat quality presented a constantly decreasing trend.The high-value zones were mainly distributed in the mountainous areas,while the low-value zones were mostly located in built-up areas.During the period of 1975-2010,low-value zones gradually expanded to their surrounding high-value zones,and the high-value zones of habitat quality tended to be fragmented.(2)The spatial-temporal variation characteristics of habitat quality from 1975 to 2010 showed that the regions with low habitat quality were difficult to be restored and mostly maintained their original state;the regions with poor habitat quality,which accounted for 6.40%of the total study area,continued to deteriorate,mainly around built-up areas;the regions with good and superior habitat quality,which accounted for 5.68%of the total study area,were easily converted to regions with bad or poor habitat quality,thus leading to the fragmentation of the regional habitat.(3)From 1975 to 2010,land use changes in the study area were significant and had a huge influence on habitat quality;the habitat quality in the study area decreased consistently,and the area of the regions with bad and poor habitat quality accounted for more than 60%of the total study area.Construction land was the largest factor threatening habitat quality.     

农用地集约利用潜力评价方法研究

土地集约利用是新一轮土地利用总体规划修编前期研究的重要内容.土地利用潜力评价方法是研究土地集约利用的关键技术.从农用地分等成果入手,用农用地集约利用潜力系数对其集约利用潜力进行评价,界定了农用地集约利用潜力内涵,阐述了农用地集约利用潜力系数的概念,提出了利用产能潜力系数和效益潜力系数计算集约利用潜力系数的方法.利用农用地集约利用潜力系数,对临沂市农用地的集约利用潜力进行了评价分析.