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无人机影像具有数量多、畸变大、POS数据不准确等特点,导致其在拼接过程中会产生大量的累积误差,要快速地获得大范围准确的全景图有一定的困难。基于此,提出一种既精确又高效的无人机序列影像拼接方法。首先计算大致的影像匹配区域,减少特征搜索和匹配的时间,同时记录匹配区域中心位置的特征点坐标,引入平差理论,区分平地、丘陵、山区等不同区域加权纠正匹配特征点的坐标位置。同时针对航带间重叠率小、姿态差异大等特点,采用"先航带间再航带内、旁边航带向中间航带靠拢"的拼接方式,减少整体区域的累积误差产生,最终完成全局影像的拼接。 相似文献
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基于Harris与RANSAC算法的无人机影像拼接方法研究 总被引：1，自引：0，他引：1
针对Harris算法在进行无人机影像拼接时的特征点误匹配问题,利用RANSAC算法对误匹配的特征点进行剔除,进而实现无人机影像的无缝拼接。首先,基于Harris算法提取兴趣点,利用最短欧式距离进行特征匹配;然后,利用RANSAC算法实现对特征点的精确匹配;最后,利用RANSAC算法得到的单应性矩阵完成无人机影像拼接。实验结果表明:本文方法能够较好地剔除无人机影像拼接时误匹配的特征点,实现对无人机影像的拼接,拼接效果良好。 相似文献
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针对无人机影像受成像角度倾斜、光照不均匀等影响,导致常规匹配方法拼接效果较差的问题,该文提出一种基于现有卫星影像的由粗到精无人机图像自动拼接方法。首先,在对图像进行粗匹配阶段,提出了一种基于环状描述子的尺度不变特征变换,用于解决图像间旋转和尺度的差异,较好地克服了SIFT算法描述子维度较高且计算量大的不足。其次,引入分块互信息进行精匹配,减少拼接过程中的累计误差。最后,采用该文提出算法对无人机图像进行拼接,实验结果表明,该文提出的无人机图像拼接算法在满足实时性要求的同时可以达到较高精度。 相似文献
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为提高无人机航摄影像快速拼接速度和精度,文章针对无人机影像处理特点,提出重叠区分块并行处理策略;通过对不同图像分辨率和尺度下的特征匹配情况进行分析,提出分块阈值自适应调节方法来改进SIFT算法;利用匹配点距离中误差进行粗差去除,获取最优RANSAC样本,得到更精确匹配点对。实验结果证明,改进策略既保证拼接的精度,又提高了拼接的效率。 相似文献
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基于SURF算法的无人机遥感影像拼接技术 总被引：2，自引：0，他引：2
在影像匹配的研究上,SIFT算法在特征匹配方面的应用一直是国内外学者关注的热点之一。最近几年,有研究者提出了SURF算法,该算法是在SIFT算法基础上作了一些改进后得到的新算法。为了比较这两种算法在影像特征点提取上的优劣性,本文开发了相应的软件程序,并采用无人机遥感影像数据进行了算法的实例验证。发现相比于SIFT算法,SURF算法在影像特征点提取中无论是运算速度还是提取的特征点数量都有较大进步。基于此将SURF算法应用到无人机遥感影像拼接中,并通过高斯滤波对拼接影像进行平滑处理,获得了令人满意的拼接影像。 相似文献
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结合SIFT特征点和泊松融合的无人机遥感影像拼接技术 总被引：1，自引：0，他引：1
针对无人机遥感影像拼接技术的研究,本文提出了一种结合尺度不变的SIFT特征点和重叠过渡泊松融合的无人机遥感影像无缝拼接方法。该方法首先采用SIFT算法对影像进行特征点提取,根据特征描述符间的欧氏距离对特征点进行粗匹配;然后使用随机采样一致性（RANSAC）算法剔除误匹配点对,为防止计算出的单适应矩阵线性结构不稳定,引入LM算法对单适应矩阵进行优化;最后采用重叠过渡泊松融合算法对影像进行拼接融合,以实现影像的无缝拼接。试验结果表明,该方法在无人机遥感影像拼接方面具有优势,能够获得良好的拼接影像。 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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Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services
Kohei OGAWA Edward VERBREE Sisi ZLATANOVA Naohiko KOHTAKE Yoshiaki OHKAMI 《地球空间信息科学学报》2011,14(2):109-118
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders. 相似文献
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地理数据库的关系模型及其实现 总被引：1，自引：0，他引：1
本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。 相似文献