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提出了一种以有效区域约束的Voronoi图为拼接线网络,利用GPU-CPU协同处理航空影像快速拼接方法。首先,基于成像有效区域生成有效区域约束的Voronoi图拼接线网络,解决了传统Voronoi图拼接线网络在低重叠度条件下拼接后影像局部区域不被覆盖的问题,然后利用GPU-CPU协同处理将正射纠正嵌入到影像拼接的过程中,并且只对每张影像的有效区域进行纠正,再通过选择配置优化和存储层次性优化进一步提高拼接效率。实验表明,对237张高分辨率航空影像进行快速正射纠正和拼接,本文算法较传统先纠正再拼接的方法效率提高近20倍,同时保证很高的拼接精度,可以满足应急测绘要求。 相似文献
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研究了移动测量系统宽幅影像的拼接与量测算法。通过建立三幅影像柱面全景投影的几何关系,能够直接拼接完成宽幅影像。利用宽幅影像和原始影像间反投影变换关系以及三幅原始影像的同、异步立体像对,可建立宽幅影像与物方空间坐标间一一对应关系,从而实现宽幅影像目标的量测算法。宽幅影像的投影拼接和量测实验表明,利用柱面全景投影拼接得到宽幅影像的方法可应用于移动测量平台宽幅影像序列的拼接;在原始影像具备同步立体像对的条件下,宽幅影像量测的绝对精度可达1 m以内,相对精度可达0.2 m以内,满足城市环境实景目标量测的精度需求。 相似文献
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针对传统影像拼接方法需要控制点的问题,该文提出一种基于位姿信息的小型无人机影像拼接方法。首先从机载GPS和惯性导航单元获取无人机拍摄的位置姿态参数,利用Harris算法提取特征点,采用SIFT描述方法计算特征向量,通过近似最近邻算法和PROSAC算法对匹配的同名点对精化。然后根据同名点对像平面坐标和航拍时的位置姿态信息,计算影像之间的变换矩阵,通过最小二乘原理平差计算以提高变换矩阵精度。最后利用变换矩阵实现无人机多幅影像的拼接,得到兴趣区域全景图。实验结果验证了该方法在拼接效果方面具有优势。 相似文献
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仅用虚拟控制点的超大区域无控制区域网平差 总被引:2,自引:1,他引:1
利用光学卫星影像进行无控制测图是摄影测量追求的目标。针对超大区域无控制测图的需求,本文提出了一种以单景影像为平差单元,基于虚拟控制点的光学卫星影像超大规模无控制区域网平差方法。该方法利用待平差影像的初始RPC模型生成虚拟控制点,并将其作为带权观测值引入平差模型中以改善平差模型的状态,克服了在无控制点条件下平差精度不稳定、误差过度累积引起的网的扭曲变形等问题。为了验证本方法的有效性和精度,利用资源三号卫星获取的覆盖全国的26 406景影像进行区域网平差试验,并利用全国范围内分布的约8000个高精度控制点对平差后自动生产的DOM和DSM产品的几何精度进行验证。试验结果表明,平面和高程中误差均达到了4m以内,同时,区域网内部相邻影像之间的几何拼接精度优于1个像素,满足无缝拼接的要求。 相似文献
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根据WorldView高分辨率卫星影像的特点,结合数字空中三角测量原理,为了减少外业像控点工作量,进行稀少控制多模型区域网平差方法进行卫星影像的数字空中三角测量生产试验。在数字空三完成后,进行模型拼接检查,使用一定数量的检查点检查立体模型成果精度,最终得出对卫星影像使用稀少控制多模型区域网平差方法可达到的精度指标。最终为WorldView卫星影像的稀少控制数字空三作业提供可靠的理论依据和合理的作业方法。 相似文献
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针对目前使用数字正射影像图(DOM)作为控制资料,纠正卫星影像,容易造成几何形变的误差传递的问题,该文提出了构建原始影像基准网,进行大区域卫星影像区域网平差的方法。该方法使用外业控制点作为地面控制资料,激光点云生产的数字高程模型(DEM)数据作为高程资料,利用区域网平差技术解算基准网影像的有理多项式系数(RPC)文件,配合DEM辅助弱连接点检测技术增强基准网的稳健性,而后利用高精度连接点匹配基准网解算同源待平差影像的RPC文件。该文使用该方法建立了基于39景高分二号影像的河南安阳、鹤壁地区的基准网,并对两景新增影像进行平差处理。结果表明,平面中误差为1.6m,达到1∶10 000数字正射影像生产的精度要求,相邻影像之间的几何拼接精度优于1个像素,满足了无缝拼接。 相似文献
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采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的
污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体
污染变化曲线,得出污染物浓度随着远离上游而增加。 相似文献
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Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data 总被引:5,自引:0,他引:5
C. Bhuiyan R.P. Singh F.N. Kogan 《International Journal of Applied Earth Observation and Geoinformation》2006,8(4):289-302
The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw. 相似文献
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Piyoosh Rautela Ramesh Chandra Lakhera 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies. 相似文献
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ZHAN F. Benjamin 《地球空间信息科学学报》2011,(1)
Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200... 相似文献
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GNSS系统及其技术的发展研究 总被引:3,自引:1,他引:2
阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议. 相似文献
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“4D”技术及其应用 总被引:13,自引:0,他引:13
介绍“4D”(即数字地面模型、数字正射影像、数字栅格地图和数字线划地图)系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):66-87
Abstract Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised. 相似文献
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自动车辆定位导航系统中传感器的误差分析 总被引:1,自引:0,他引:1
对国界定位导航系统中几种常见的辅助传感器所产生的误差进行了分析,导出了不同传感器的误差模型。这些误差模型是估计车辆位置的扩展卡尔曼滤波器的基础,同时也为选择适当的传感器提供了理论根据。 相似文献