共查询到20条相似文献，搜索用时 156 毫秒
1.
1∶2000地形图地面点高程精度是15cm,北京东部地区地面沉降每年约5cm,每年造成已有的地形图三分之一不合格。本文比较了地形图高程测量的方法:水准测量、GPS测量、航空摄影测量、LiDAR、InSAR等,提出了建立沉降区高程改正模型的观点。即利用外业施测的高程改正控制点的沉降量(改正值)和平面坐标,通过插值算法进行高程拟合,得到高程改正模型,作为内业建立高程改正数学模型的依据。 相似文献
2.
介绍了余姚市城区大比例尺地形图高程改正项目的实施,通过分析余姚市地面沉降的情况．提出了基于TIN的地面沉降模型实施高程改正的思路,并就项目的具体实施进行了简要剖析。 相似文献
3.
讨论对LIDAR点云的高程值进行再次改正的必要性和改正方法,提出构建Delaunay三角网对LIDAR点云的高程值进行再次改正的方法,实例改正结果表明,改正后的LIDAR点云的高程精度能够大幅度提高。 相似文献
4.
张克非 《武汉大学学报(信息科学版)》1990,(3)
本文在顾及局部地形改正、椭球改正及大气改正的情况下,采用实测数据,应用Meissel方法和Wenzel频谱分析方法,对某盆地边缘的高程异常进行了实际计算。并将计算结果同多普勒高程异常进行了比较,证明结果是良好的。此外还对我国精确高程异常的确定提出了一些建议。 相似文献
5.
利用GPS载波相位差分测量技术，借助时间偏差改正、姿态改正、高程转换、信号处理和吃水改正，获得了测船处精密在航潮位。该方法已在几个GPS在航潮位测量实验中得到了验证，并取得了理想的结果。 相似文献
6.
7.
8.
介绍了1∶50 000重力勘查中提高测地工作的新思路,提出了采用GPS-RTK方法,利用CORS网站测定重力测点点位3维坐标的作业方法、消除高程异常影响而建立似大地水准面模型的方法及建立DTM数字高程模型在计算机上进行地形改正方法等。 相似文献
9.
以《张涿高速公路1∶2 000数字地形图及数字高程模型项目》为例介绍了一种山地高程控制测量的方法,为带状地形测区提供了一种有效的高程控制测量方法。 相似文献
10.
11.
12.
Void filling and anomaly replacement in conjunction with auxiliary sources of data have been widely used to improve the quality of existing problematic high-resolution digital elevation models. However, the traditional interpolation methods used for this purpose have always failed to eliminate the discrepancies between different data-sets. In this paper, an improved ANUDEM method is presented for DEM interpolation, which incorporates the idea of topographic correction using high correlation of topological structure between contour lines (CLs) from multi-scale digital elevation models (DEM). Firstly, the terrain topological structure is extracted from the CLs of a low-resolution DEM. The topographic surface correction is then undertaken based on the extracted structure, which recovers the topographic information of the sharp depressions and eminences to fit the high-resolution representation. Finally, the breaklines of the terrain surface are distilled and integrated into the denser DEM generation. The experiments undertaken confirmed the superiority of the proposed method over the other DEM interpolation methods. It is shown that the proposed method can provide results with a higher accuracy, as well as a better visual quality. 相似文献
13.
论述了数字地形图中产生高程点与等高线错误的可能原因,分析了高程点和等高线在地形图中的空间位置关系及作为判断条件的数学关系,论述了解决问题的办法和判断规则,展示了通过编制计算机程序实现找出其错误的核心代码,此研究对于减轻质检人员在检查数字地形图的高程点与等高线错误时的劳动强度和提高工作效率很有意义。 相似文献
14.
15.
Topographic corrections of synthetic aperture radar (SAR) images over hilly regions are vital for retrieval of correct backscatter values associated with natural targets. The coarse resolution external digital elevation models (DEM) available for topographic corrections of high resolution SAR images often result into degradation of spatial resolution or improper estimation of backscatter values in SAR images. Also, many a times the external DEMs do not spatially co-register well with the SAR data. The present study showcases the methodology and results of topographic correction of ALOS-PALSAR image using high resolution DEM generated from the same data. High resolution DEMs of Jaipur region, India were generated using multiple pair SAR images acquired from ALOS-PALSAR using interferometric (InSAR) techniques. The DEMs were validated using differential global positioning system measured elevation values as ground control points and were compared with photogrammetric DEM (advanced spaceborne thermal emission and reflection radiometer – ASTER) and SRTM (Shuttle Radar Topography Mission) DEM. It was observed that ALOS-PALSAR images with optimum baseline parameters produced high resolution DEM with better height accuracy. Finally, the validated DEM was used for topographic correction of ALOS-PALSAR images of the same region and were found to produce better result as compared with ASTER and SRTM-DEM. 相似文献
16.
17.
Arseny Zhogolev 《国际地球制图》2018,33(6):573-586
The digital elevation model based on SRTM is very convenient for a wide range of studies but requires correction due to the influence of forest vegetation. The present study was conducted to analyse the effect of boreal forests on altitudes, aspects and slopes calculated from the SRTM. A DEM based on topographic maps at 1:100 000 scale was used as a reference. The linear regression analysis showed low data correlation in forested areas. The presence of different types of forests and felling in the woods leads to a complex distribution of deviations from the SRTM. A simple correction method was proposed, using a forest mask, built according to Landsat, and forest heights indicated on the topographic maps. After correction, the correlation coefficient between the altitudes increased by 0.05–0.14, the share of matching aspects by 1–4% and the share of matching slopes by 2–8%. 相似文献
18.
联合使用位模型和地形信息的陆区航空重力向下延拓方法 总被引：1，自引：0，他引：1
为了规避传统逆Poisson积分向下延拓解算过程的不适定性问题,借鉴导航定位中的"差分"概念,利用超高阶位模型直接计算海域航空重力测量向下延拓改正数的方法。本文在此基础上提出联合使用重力位模型和地形高数据,计算陆部航空重力向下延拓总改正数的改进方案,以飞行高度面与地面对应点的位模型差分信息表征总改正数的中长波分量,以相对应的局部地形改正差分修正量表征总改正数的中高频成分,从而实现航空重力数据点对点向地面的全频段延拓。在地形变化不同区域,联合使用EGM2008位模型、地面实测重力和高分辨率高程数据进行了实际数值计算和精度评估,验证了该方法的有效性。 相似文献
19.
基于特征点的高程点自动抽稀法 总被引：1，自引：0，他引：1
针对传统地形图缩编中高程点抽稀存在的问题,提出基于特征点的高程点抽稀的方法,使用此方法一方面可以保留特征点处的高程点,另外可以实现高程点的自动抽稀。 相似文献
20.
三维可视化技术的发展日益成熟,本文以ERDAS IMAGINE软件为基础,利用Arc GIS软件将该地形图的高程数据转换为高精度的数字高程模型,通过影像的几何校正后,将DEM影像与该区域的多光谱影像图进行叠加,从而实现了三维地形的可视化。几何校正后的三维地形真实感更强,并在此基础上分析了三维地形可视化的应用,对于虚拟现实技术的迅速发展有着重要的意义。 相似文献