高分辨率遥感卫星立体影像RPC模型定位的算法及其优化

介绍了高分辨率遥感卫星影像的RPC模型,重点探讨了基于RPC模型的立体定位算法,并给出了补偿RPC模型系统误差的物方方案和像方方案.针对IKONOS卫星数据的实验结果表明,这些方案能有效地消除RPC模型的系统误差,达到的定位精度能满足1:10000比例尺的地形图测绘要求.     

Comparing 1D and combined 1D/2D hydraulic simulations using high-resolution topographic data: a case study of the Koiliaris basin,Greece

The development of high spatial resolution digital elevation models takes place via the use of GeoEye-1 stereo-pair imagery, providing highly accurate geometrical representations of complex riverine systems. The combination of geographic information systems with hydraulic models facilitates the exploitation of satellite topographic information throughout the cross-section extraction process. One-dimensional HEC-RAS and combined 1D/2D HEC-RAS models are adjusted by making use of the resulting high-resolution input. Several hydraulic simulations are effectuated in order to test how significantly DEM resolution affects hydraulic modelling results, with regard also to the model dimensionality. The ability of the combined 1D/2D model, based mainly on the high-accuracy input data, provides an accurate estimate of the flood hazard area. Flood-prone areas could take advantage of high-accuracy results and facilitate the effective management of extreme events and sufficient decision making.     

Universal algorithm for water depth refraction correction in through-water stereo remote sensing

In through-water stereo remote sensing, the correction of the effect of light refraction on water depth determination is an unsolved problem. The challenge is that no solution exists for apparent positions when the conjugate image rays are non-intersecting. This paper proposes a new water depth refraction correction algorithm for through-water stereo remote sensing. The midpoint of the shortest line segment between two non-intersecting conjugate image rays is used as the apparent position, so that the mathematical relationship between the apparent and actual depths is established under the “no solution condition”. The new algorithm is reasonable and applicable whether or not conjugate image rays are intersecting. Compared with the existing algorithms, the new algorithm can improve bathymetric accuracy in different degrees. The improvement becomes more significant as the off-nadir view angle difference and the depth increase. Results for Area 1 showed that, compared with the three existing algorithms, the new algorithm improved RMSE accuracy by about 22%, 29% and 24% respectively. The new algorithm enables reasonable water depth refraction correction to be implemented in any case (whether conjugate image rays are intersecting or not).     

微分纠正法生成立体辅助影像探讨

针对数字正射影像(DOM)的二维平面形式,没有三维立体信息,对高层建筑等细部高度不能量测的问题,探讨通过数字微分纠正的方法,引入固定平行角度投影光线的视差函数,制作立体辅助影像,并与原正射影像共同构成立体正射影像对,构建与实地相似的几何模型,进行立体观察,量测地物高度信息,为城市规划等部门的实际应用提供解决方案。最后给出了实验结果,并对其量测的高度结果也进行了检测。     

地面序列影像的高陡边坡高精度三维建模方法

本文针对高陡边坡地形特点,介绍一种基于普通数码相机的多基线地面摄影测量方法,重点研究了普通数码相机的量测化方法和高陡边坡序列数码影像的匹配方法。通过对普通数码相机的量测化,提高了高陡边坡地区数据采集的效率,降低了作业对影像控制和算法的要求;采用种子点与多重约束相结合的多基线匹配方式,解决了高陡边坡序列数码影像匹配中存在的遮挡多、左右片变形大、比例尺不一致等匹配难题。上述建模过程快速且能获得很高精度,实验表明三维建模的相对精度达1/8000~1/12000。     

Modeling and sensitivity analysis of navigation parameter errors for airborne synthetic aperture radar stereo geolocation

For the high-resolution airborne synthetic aperture radar (SAR) stereo geolocation application, the final geolocation accuracy is influenced by various error parameter sources. In this paper, an airborne SAR stereo geolocation parameter error model, involving the parameter errors derived from the navigation system on the flight platform, has been put forward. Moreover, a kind of near-direct method for modeling and sensitivity analysis of navigation parameter errors is also given. This method directly uses the ground reference to calculate the covariance matrix relationship between the parameter errors and the eventual geolocation errors for ground target points. In addition, utilizing true flight track parameters’ errors, this paper gave a verification of the method and a corresponding sensitivity analysis for airborne SAR stereo geolocation model and proved its efficiency.     

利用IKONOS卫星影像测制新疆边境1∶10000比例尺地形图

在不能实施基础航空摄影的新疆边境地带,利用高分辨率遥感卫星影像来弥补无航空摄影资料区域对1∶10000地形图的需求。本文简要介绍利用IKONOS立体卫星影像,在平地、丘陵地及山地测制1∶10000比例尺地形图的技术方案,并对不同数量控制点进行定向精度分析。     

多角度卫星影像的DEM制作

随着卫星传感器的不断发展,不同传感器的应用也随之更加广泛,其中可以进行单轨立体测绘的多角度影像产品的发布为DEM生产提供了更多选择。由于多角度观测卫星可同时提供多角度观测数据,提供立体像对,从而可以在较少的信息中提取较高精度的DEM产品。本文基于Carto SAT-1卫星获取的多角度卫星影像,对DEM生产方法进行了论述,对其发展前景做了展望。     

浅谈基于全景立体的智慧校园智慧教学研究——以江西应用技术职业学院为例

智慧校园建设同智慧小区建设一样,是智慧城市、智慧中国,乃至智慧地球建设的基础部分。本文以江西应用技术职业学院为例,主要探讨了基于全景立体的智慧校园智慧教学研究的基本概念、研究内容、技术路线流程、特色和创新点及实现的可行性,为智慧校园的进一步研究和实现提供了理论与技术支撑,同时也为智慧社区等类似的研究提供技术和实践借鉴。     

Fine‐scale patterns in the day,night and crepuscular composition of a temperate reef fish assemblage

The distribution, abundance and composition of marine fish assemblages are influenced by changes in behaviour and movement associated with the diel cycle. The majority of studies exploring day–night differences have demonstrated that there is a greater abundance and diversity of fishes during diurnal compared with nocturnal hours, and that fish assemblage composition varies with time of day or night. We investigated fine‐scale (hourly) diel cycles in the composition and relative abundance of temperate reef fishes using unbaited remote underwater video systems. We observed short crepuscular changeover periods with the hours around dawn and dusk sharing many species, some of which are nocturnal and others diurnal. Diurnal surveys recorded a greater number of individuals (16,990) and species (70) than nocturnal surveys (1053 individuals and 19 species). There was a clear difference between the diurnal assemblage, which was characterized by benthic invertivores, and the nocturnal assemblage composition, which contained zooplanktivores and generalist feeders. Within the diurnal period the hourly temporal variation was relatively homogenous, indicating that standardization of diurnal sampling to a particular time of day may not be necessary.