Comparison between Plane and Stereo Block Adjustment for ZY-3 Satellite Images

Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method.First,a rational function model with affine transformation is selected as the mathematical model of the satellite image plane block adjustment.Second,to update the ground coordinates of tie points(TPs),the plane coordinates of TPs are only solved in the adjustment process.Elevation values are obtained by using DEM interpolation.Finally,the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment.A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1∶50 000 DEM and stereo block adjustment for ZY-3 images.For ZY-3 nadir images,almost no loss of plane block adjustment accuracy occurred when global DEM with 1 km grid and SRTM with 90 m grid replaced the 1∶50 000 DEM as elevation control,.Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.

国产GF-2和ZY-3卫星数据在活动断裂定量研究中的应用——以哈思山南麓断裂带为例

利用国产GF-2和ZY-3卫星数据,以海原断裂带哈思山南麓断裂为例,应用目视综合解译、三维立体解译,结合野外验证,定量分析国产高分数据在活动构造定量研究中的应用潜力。GF-2融合影像展示了清晰的断层陡坎、冲沟左旋断错及同震破裂等现象,依据解译结果哈思山南麓断裂可分为正走滑型的荒凉滩—沙葱沟段、左旋走滑型的沙葱沟—黄河段以及以左旋运动为主黄河—沈家庄段。沿断裂带进行的1∶50 000遥感解译工作在地层边界、构造微地貌细节信息提取等方面均有较大的改进,解译得到的最小左旋水平位移量4.3m,反映1920年海原地震的水平同震位移量,而最大左旋水平位移量333.5m,则反映该段晚第四纪的持续运动。研究表明,海量国产高分辨率卫星数据在中国西部活动构造定量研究中可替代国外同等分辨率的数据,具有较强的应用价值。

双CMOS仿生3D视觉传感器电路设计

针对目前3D相机中出现的图像数据易丢失、左右图像同步难等问题,提出一种可精确采集左右格式立体对图像的仿生3D传感器实现方法,可为仿生3D传感器的光路系统的检验及目标物三维重建提供精确三维坐标信息。为更好协调3D传感器在光信号处理中的点像素同步,采用现场可编程门阵列处理双OV3640图像传感器各信号,初始化后在像素时钟的准确控制下采集图像数据并完成输出图像格式转换、缓存、左右格式立体对图像拼接及输出显示验证。结果表明,3D传感器工作可靠、集成度高、体积小,可精确采集左右格式立体对图像。

基于WorldView-3遥感影像与机载LiDAR的单木树高提取

基于WorldView-3影像与机载LiDAR数据,结合地面每木定位调查,采用冠层高度模型法提取天山云杉单木树高,比较分析不同数据源提取单木树高的精度,为山地天然林单木高度提取提供方法依据。以新疆农业大学实习林场天山云杉为研究对象,实测单木树高,并用RTK每木定位。以WorldView-3遥感影像、LiDAR点云为数据源,分别通过立体像对与布料模拟滤波分类的方法提取LiDAR与WorldView-3两种数字表面模型(DSM),以LiDAR点云生成的数字高程模型(DEM)为基础,解算两种数据的冠层高度模型(CHM)获取单木高度。基于LiDAR与WorldView-3数据的天山云杉单木识别率较高,平均识别率为96.3%和93.7%,平均漏检率为3.7%和6.3%;利用LiDAR提取树高的精度较高,平均精度为90.50%,而采用WorldView-3提取树高的精度略低于前者,平均精度为83.28%。通过对机载激光雷达点云数据进行布料模拟滤波分类,能够获得高精度的DEM数据,通过二者叠加运算是一种提取单木树高可行的方法;基于WorldView-3影像进行立体像对可以获得精度较高的DSM,在拥有高精度DEM基础数据的情况下,可以作为调查范围较大、成本有限的森林资源调查树高提取方法。