共查询到20条相似文献，搜索用时 189 毫秒
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在实际工作中我们采用GPS、全站仪结合航测影像图的作业方法进行了外业快速数据采集,并利用南方CASS软件对数据进行内业成图工作。本文介绍了GPS(RTK)配合全站仪在湟中县土门关乡农村集体土地所有权确权登记和发证工作中的作业流程,此方法具有速度快、效率高和精度高等优点。 相似文献
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三维激光扫描仪在道路竣工测量中的应用 总被引：1，自引：1，他引：0
三维激光扫描仪在道路竣工测量中的应用相对于常规作业方式极大地提高了作业效率,降低了外业劳动量和劳动强度。由于三维激光扫描仪能够迅速采集大量的点云数据,实景再现了测区的地形地势,相对于传统的作业方法具有无法比拟的优势。全文概略介绍了三维激光扫描技术的工作原理,详细介绍了三维激光扫描技术在道路竣工测量中的内外业作业方法,同时进行了多方面的精度检验,为三维激光扫描技术在其他相关工程中应用的提供了很好的借鉴作用。 相似文献
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无人机低空航空摄影测量是近几年发展的新兴测绘技术,eBee是近几年才从国外引进的,属于轻小型固定翼无人机系统,在国内测绘领域应用还处于探索和发展阶段。据此,以生产大比例尺地形图为目标,设置实验项目并拟定多套测试方案,对该无人机系统进行相关试验性数据生产,实施精度检测和数据分析,得出相关几何精度等数据指标,并根据试验实践总结出利用eBee无人机航摄系统应用于大比例尺成图可行的作业技术路径。提出了相关作业技术方法,从中总结经验,发表了自己的技术观点,对无人机系统和低空航空摄影测量技术应用于测绘生产具有较好的参考和借鉴作用。 相似文献
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介绍了互联网地图在公路测量中的找点、选线、测图、绘图环节中的应用方法,阐述了传统纸质地图和互联网地图在公路测量中各环节的作业流程、技术方法、投入的人员等各自特点,同时对二者的优缺点进行了分析比较,得出了互联网地图较纸质地图在成图、作业效率、质量保障等方面的明显优势,同时还探讨了互联网地图作业中的涉密问题和作业员在测量中应遵循的保密法则。互联网地图内容丰富形象,具有可与GPS定位联动的实时性。互联网地图的应用改变了传统作业模式,提高了公路测量的工作效率和作业质量,降低了项目成本,对公路测量工作具有重要的现实意义。 相似文献
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对手持GPS接收机配合CORS的技术方案应用于土地开发验收过程的作业方法和步骤进行了详细阐述,并对测量结果的精度进行了验证分析,对类似测量工作具有一定的指导意义。 相似文献
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论述了数字航测技术应用于土地利用详查工作的技术流程和作业方法,重点阐述了在立体模型上测绘图斑地类界线制作外业调绘底图开展土地详查的作业流程和方法,以及采用此方法对于提高土地详查工作的作业效率、成果质量以及提高成果的数字化水平所具有的突出优势。 相似文献
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论述了数字航测技术应用于土地利用详查工作的技术流程和作业方法,重点阐述了在立体模型上测绘图斑地类界线制作外业调绘底图开展土地详查的作业流程和方法,以及采用此方法对于提高土地详查工作的作业效率、成果质量以及提高成果的数字化水平所具有的突出优势。 相似文献
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局部均值分解方法降噪过于粗糙,将认定为噪声的乘积函数(PF)分量直接剔除,导致有用信息丢失.为了有效提取GNSS站坐标时间序列的有用信息,该文提出一种局部均值分解和小波阈值相结合的降噪方法.通过局部均值分解将坐标时间序列分解为一系列PF分量和余项,依据消除趋势波动分析方法计算各PF分量的Hurst指数,利用小波阈值提取H≤1的PF分量中的有用信息,将提取出的信息与剩余PF分量叠加重构获得最终降噪的坐标时间序列.通过对5个测站的坐标时间序列进行实验,结果表明局部均值分解和小波阈值相结合的方法能够有效提取噪声分量中的有用信息,信噪比提高了27.8％,从而验证了该方法的有效性. 相似文献
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Li‐Yang Xiong Ru‐Qiao Jiang Qing‐Hui Lu Bi‐Sheng Yang Fa‐Yuan Li Guo‐An Tang 《Transactions in GIS》2019,23(2):259-274
Depression filling is a critical step in distributed hydrological modeling using digital elevation models (DEMs). The traditional Priority‐Flood (PF) approach is widely used due to its relatively high efficiency when dealing with a small‐sized DEM. However, it seems inadequate and inefficient when dealing with large high‐resolution DEMs. In this work, we examined the relationship between the PF algorithm calculation process and the topographical characteristics of depressions, and found significant redundant calculations in the local micro‐relief areas in the conventional PF algorithm. As such calculations require more time when dealing with large DEMs, we thus propose a new variant of the PF algorithm, wherein redundant points and calculations are recognized and eliminated based on the local micro‐relief water‐flow characteristics of the depression‐filling process. In addition, depressions and flatlands were optimally processed by a quick queue to improve the efficiency of the process. The proposed method was applied and validated in eight case areas using the Shuttle Radar Topography Mission digital elevation model (SRTM‐DEM) with 1 arc‐second resolution. These selected areas have different data sizes. A comparative analysis among the proposed method, the Wang and Liu‐based PF, the improved Barnes‐based PF, the improved Zhou‐based PF, and the Planchon and Darboux (P&D) algorithms was conducted to evaluate the accuracy and efficiency of the proposed algorithm. The results showed that the proposed algorithm is 43.2% (maximum) faster than Wang and Liu's variant of the PF method, with an average of 31.8%. In addition, the proposed algorithm achieved similar performance to the improved Zhou‐based PF algorithm, though our algorithm has the advantage of being simpler. The optimal strategies using the proposed algorithm can be employed in various landforms with high efficiency. The proposed method can also achieve good depression filling, even with large amounts of DEM data. 相似文献
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Guiying Li Emilio Moran Miquéias Freitas Calvi Luciano Vieira Dutra Mateus Batistella 《地理信息系统科学与遥感》2019,56(2):161-183
This research aims to understand the difference of major land-cover change results caused in various time periods and to examine the impacts of human-induced factors on land-cover changes along the TransAmazon Highway region. The Landsat Thematic Mapper and Operational Land Imager data from 2011, 2014, and 2017 and our previous land-cover classification results in 1991, 2000, and 2008 were used to examine land-cover dynamics. A classification system consisting of five land-cover classes – primary forest (PF), secondary forest (SF), agropasture (AP), urban area, and water – were chosen. The hierarchical-based classification method was used to generate land-cover classification results, and the post-classification comparison approach was used to produce detailed “from-to” conversions for each detection period. The emphasis was on deforestation of PF, dynamic change of SF and AP, and urbanization over time. The impacts of human-induced factors such as population and economic conditions on urban expansion, AP expansion, and deforestation were examined. This research indicated that selection of a suitable time period was critical for effectively detecting land-cover changes; that is, too long time period (i.e., 9 years) cannot accurately capture some land-cover changes such as the AP and SF in this research. Although deforestation – the conversion from PF to SF and AP – accounted for a large proportion of land-cover changes, the changes between SF and AP became more important than PF conversion, and required a short time period (i.e., 3 years here) for effectively reflecting their dynamics. Human-induced factors play important roles in deforestation, dynamic changes between AP and SF, and urbanization. 相似文献
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Dead reckoning techniques such as inertial navigation and odometry are integrated with GPS to avoid interruption of navigation
solutions due to lack of visible satellites. A common method to achieve a low-cost navigation solution for land vehicles is
to use a MEMS-based inertial measurement unit (IMU) for integration with GPS. This integration is traditionally accomplished
by means of a Kalman filter (KF). Due to the significant inherent errors of MEMS inertial sensors and their time-varying changes,
which are difficult to model, severe position error growth happens during GPS outages. The positional accuracy provided by
the KF is limited by its linearized models. A Particle filter (PF), being a nonlinear technique, can accommodate for arbitrary
inertial sensor characteristics and motion dynamics. An enhanced version of the PF, called Mixture PF, is employed in this
paper. It samples from both the prior importance density and the observation likelihood, leading to an improved performance.
Furthermore, in order to enhance the performance of MEMS-based IMU/GPS integration during GPS outages, the use of pitch and
roll calculated from the longitudinal and transversal accelerometers together with the odometer data as a measurement update
is proposed in this paper. These updates aid the IMU and limit the positional error growth caused by two horizontal gyroscopes,
which are a major source of error during GPS outages. The performance of the proposed method is examined on road trajectories,
and results are compared to the three different KF-based solutions. The proposed Mixture PF with velocity, pitch, and roll
updates outperformed all the other solutions and exhibited an average improvement of approximately 64% over KF with the same
updates, about 85% over KF with velocity updates only, and around 95% over KF without any updates during GPS outages. 相似文献
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在农村土地承包经营权确权过程中,利用图解法在分辨率高的数字正射影像图基础上进行调绘可以节省大量的劳动力和工作经费。在调绘时,一个地块往往会分给多个承包方,根据村组提供的合同面积以及影像来图解出实际面积。针对此情况,本文提出一种地块面积自动分割的方法,并基于Arc GIS Engine和C#语言实现了该算法,结合实例表明,该方法快速而有效,大大提高了绘制过程的工作效率,节省了时间,具有较好的实用价值。 相似文献
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第二次土地调查工作时间紧、任务重,如何提高外业作业效率成为整个工作的关键.文章在论述传统方法缺陷的基础上,提出了提高土地二调外业作业效率的方法,极大地方便了地籍补测工作,其精度好、效率高,是一种全新的外业测量方式. 相似文献
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城市现状建筑容积率的分类提取对于有效把握城市用地开发强度以及制定科学合理的控制性详细规划具有重要参考意义。提出了一种主成分分量、主方向、边界指数以及矩形拟合度等多特征分量相结合的超高分辨率卫星影像建筑容积率贝叶斯分类提取方法。基于分类结果，采用阴影面积法与阴影长度法计算容积率并进行精度对比验证。利用WorldView-3卫星影像进行提取实验，并对实验区建筑逐一进行实地调查，结果表明，在容积率计算中，阴影面积法总体精度为93.90%，阴影长度法总体精度为85.19%，阴影面积法较阴影长度法在容积率分类提取精度上优势更突出。 相似文献
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为了进一步提高冬小麦产量估测的精度,基于集合卡尔曼滤波算法和粒子滤波（particle filter, PF）算法,对CERES–Wheat模型模拟的冬小麦主要生育期条件植被温度指数（vegetation temperature condition index,VTCI）、叶面积指数（leaf area index, LAI）和中分辨率成像光谱仪（moderate-resolution imaging spectroradiometer, MODIS）数据反演的VTCI、LAI进行同化,利用主成分分析与Copula函数结合的方法构建单变量和双变量的综合长势监测指标,建立冬小麦单产估测模型,并通过对比分析选择最优模型,对2017—2020年关中平原的冬小麦单产进行估测。结果表明,单点尺度的同化VTCI、同化LAI均能综合反映MODIS观测值和模型模拟值的变化特征,且PF算法具有更好的同化效果;区域尺度下利用PF算法得到的同化VTCI和LAI所构建的双变量估产模型精度最高,与未同化VTCI和LAI构建的估产模型精度相比,研究区各县（区）的冬小麦估测单产与实际单产的均方根误差降低了56.25 kg/hm2,平均相对误差降低了1.51%,表明该模型能有效提高产量估测的精度,应用该模型进行大范围的冬小麦产量估测具有较好的适用性。 相似文献