资源一号02B卫星影像几何外检校研究及应用

针对资源一号02B卫星,建立影像的严密成像几何模型,研究系统误差的补偿方法.实验采用GPS和AOCS的观测数据,将资源一号02B高分辨率影像的定位精度从860个像素(RMS)提高到216个像素(RMS).分析误差产生的根源,求解俯仰、滚动2个旋转角度和俯仰、滚动、偏航3个旋转角度时,均明显提高了影像的几何定位精度,对于沿轨道方向的误差加入偏航角校正优于不加偏航角校正.     

Level study on fractal characteristics of tidal creeks and information of seashell habitats in the Gaizhou Beach based on high-resolution satellite images

The fractal characteristics of tidal creeks in the Gaizhou Beach are analyzed based on high-resolution images fusion of Landsat TM and ERS-2, and then the graphic models and characteristics of converse information tree of tidal creeks in the Gaizhou Beach are established. A calculation model is established based on the above results, and at the same time, quantitative calculation of the evolution characteristics and the diversity between the northern and the southern parts of the Gaizhou Beach is carried out. By the supervised classification of these images, distribution and areas of high tidal flats, middle tidal flats and low tidal flats in the Gaizhou Beach are studied quantitatively, and image charactistics of seashell habitats in the Gaizhou Beach and the correlation between mudflat distribution and seashell habitats are studied. At last, the engineering problems in the Gaizhou Beach are discussed.     

A new family of non-linear filters for background subtraction of wide-field surveys

In this paper the definitions and properties of a newly dedicated set of high-frequency filters based on smoothing-and-clipping are briefly described. New applications for the reduction of wide-field 2048x2048 CCD spectral and direct images of a new deep survey KISS are also presented.     

黄河下游游荡段不同畸形河湾的演变特点

1980s中期以来,黄河下游游荡段经常出现畸形河湾,分析其演变过程及特点对游荡段治理具有重要意义.本研究采用黄河下游游荡段的遥感影像和实测断面地形资料,描述了不同畸形河湾的演变过程并分析其河湾形态参数和断面形态的变化.研究表明,黄河下游游荡段的畸形河湾具有演变周期短、扭曲程度较大和易发生自然裁弯等特点.游荡段不同位置畸形河湾的演变特点不同：游荡段上段的畸形河湾演变缓慢,裁弯历时长;中段的畸形河湾演变速率较高,河湾扭曲程度大;下段的畸形河湾演变速率高,容易发生自然裁弯.河湾形态参数可反映畸形河湾的演变过程,其变化特点与畸形河湾的形成和裁弯过程相对应.在畸形河湾形成过程中,曲率半径和河湾间距减小,弯曲度、水流夹角和河湾振幅增大.游荡段3个畸形河湾弯曲度的最大值分别为1.20、2.10和1.61,反映了不同畸形河湾的扭曲程度.“Ω”形畸形河湾裁弯后的曲率半径、水流夹角、河湾振幅和河湾间距约为其演变过程中最值的605%、59%、27%和133%.“M”形畸形河湾裁弯后水流夹角、河湾振幅和河湾间距约为其最值的37%、83%和152%.在畸形河湾形成时期,伊洛河口断面位于畸形河湾凹岸侧的滩地以94 m/a的速率崩塌.裁弯后,河槽冲刷,两岸滩地崩退,河槽展宽速率为148 m/a.河床底部的冲刷从深泓点逐渐向两边发展.     

Development of a flood water level estimation method using satellite images and a digital elevation model for the Mekong floodplain

We have developed a flood water level estimation method that only employs satellite images and a DEM. The method involves three steps: (1) discriminating flood areas and identifying clumps of each flood area, (2) extracting the edges of the identified flood area using a buffering technique, and (3) performing spatial interpolation to transform the extracted elevation to flood water levels. We compared the estimated flood water levels with the observed ones. The RMSE using the RADARSAT was 1.99 and 1.30 m at river and floodplain points, respectively, whereas the RMSE using the MODIS was 4.33 and 1.33 m at the river and floodplain points, respectively. Given that most errors are attributed to the DEM, the method exhibited good performance. Furthermore, the method reproduced the flow directions and flood water level changes during the flooding period. Thus, we demonstrated that the characteristics of flood inundation can be understood even when ground observation data cannot be obtained.     

Predicting biomass dynamics at the national extent from digital aerial photogrammetry

The demand for precise mapping and monitoring of forest resources, such as above ground biomass (AGB), has increased rapidly. National accounting and monitoring of AGB requires regularly updated information based on consistent methods. While remote sensing technologies such as airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) have been shown to deliver the necessary 3D spatial data for AGB mapping, the capacity of repeat acquisition, remotely sensed, vegetation structure data for AGB monitoring has received less attention. Here, we use vegetation height models (VHMs) derived from repeat acquisition DAP data (with ALS terrain correction) to map and monitor woody AGB dynamics across Switzerland over 35 years (1983-2017 inclusive), using a linear least-squares regression approach. We demonstrate a consistent relationship between canopy height derived from DAP and field-based NFI measures of woody AGB across four inventory periods. Over the environmentally heterogeneous area of Switzerland, our models have a comparable predictive performance (R² = 0.54) to previous work predicting AGB based on ALS metrics. Pearson correlation coefficients between measured and predicted changes in woody AGB over time increased with shorter time gaps (< 2 years) between image capture and field-based measurements, ranging between 0.76 and 0.34. A close temporal match between field surveys and remote sensing data acquisition is thus key to reliable mapping and monitoring of AGB dynamics, especially in areas where forest management and natural disturbances trigger relatively fast canopy dynamics. We show that VHMs derived from repeat DAP capture constitute a cost effective and reliable approach to map and monitor changes in woody AGB at a national extent and can provide an important information source for national carbon accounting and monitoring of ecosystem service provisioning.     

基于国产卫星影像的自然资源动态监测

准确及时地掌握山、水、林、田、湖、草系统变化状况,是自然资源管理重点关注的问题。卫星遥感技术具有宏观、综合、动态、快速的特点,能够应用于自然资源领域开展目标识别、信息采集与处理、分析与评估等工作,可作为自然资源监测的有效手段。本文以“土地、矿产、海洋”等重要自然资源要素为动态监测研究目标,基于多源多时相国产卫星遥感影像数据和各类审批、规划专题资料数据,开展自然资源动态监测研究。研究结果表明,深入挖掘国产卫星影像资源潜力,实现自然资源精细遥感监测服务模式是切实可行与高效的。     

基于eCognition的遥感图像面向对象分类方法研究

随着高分辨率遥感图像越来越普及,传统的面向像元的图像分类方法不能满足对高分辨率遥感图像区域分类的需求,高分辨率遥感图像对图像处理的软件与硬件都有了更高的要求,因此,出现了相较于面向像元有着更高精度更为合理的面向对象分类方法,也更加适用于高分辨率遥感影像。本文通过采用面向对象分类的基本方法,运用eCognition软件,以山东省胶州市地区遥感影像为例,进行多尺度分割和面向对象分类。并用ENVI做监督分类,基于目视解译精度评定,对不同方法作出分析评价。结果表明:面向对象分类方法精度更高,更具有可靠性。     

基于多源信息的水资源立体监测研究综述

水资源监测是水资源管理的基础和支撑。随着中国最严格水资源管理制度的实施,从水量、水质、用水效率3方面的水资源管理开始向精细化和动态化管理转变。水资源要素具有时空变异大、通量变化快等特点,单独依靠地面监测手段难以开展大范围动态高效监测。目前中国水资源监测体系的建设,总体上以地面监测为主,还不具备水资源精细化和动态化管理需求的监测能力。随着卫星遥感等数据资源的不断丰富和陆面同化系统的不断发展,建立地面观测、卫星遥感和陆面同化系统三位一体的立体监测体系,探讨不同监测方式、多要素的协同监测机理、水资源监测要素的组织机制,对提升中国水资源监控能力具有参考价值。     

基于数码航空影像的平地区域高程精度分析研究

研究了新疆范围内1∶10000基础测绘使用航空影像进行数字化测图平地区域高程精度的问题,通过外业区域网布设像控点及全野外布设像控点,检测位于平地区域DLG数据高程精度超限及精度放宽的问题,最后,得出航空影像在新疆范围内的平地区域DLG数据采集的高程中误差的限差值。