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影响无人机航测高程精度因素的研究 总被引：1，自引：0，他引：1
《现代测绘》2021,(3)
随着高科技无人机技术应用于水利测绘越来越广泛,对数据获取精度要求也越来越高,数据精度主要分为平面精度与高程精度,一般航测平面精度都能保证,如何提高航测高程精度成为数据整体精度保证的关键。航测数据获取过程主要包括外业航飞及内业数据处理,通过外业航飞及内业数据处理流程来分析影响航测立体建模高程精度影响因素,结合实验数据对比确定像片质量、像片重叠度、像主点落水三大因素对航测高程精度会产生较大影响,调整野外航飞时段、优化航飞参数设置及数据处理方式来提高无人机航测高程精度,为水利测绘进一步获取高精度影像数据提供有力的技术指导意义。 相似文献
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系统密切结合目前电力生产实际,对采用各种新仪器、应用各种先进作业手段自动采集的野外测绘原始文件进行自动预处理,实现与各种成图软件的无缝接口。内业处理部分能够接收外业、航测等采集的数据,自动生成平断面图或水文断面图,实现测绘设计一体化。 相似文献
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本文通过航测外业像控点正常高的拟合试验,对在深山峡谷地区航测外业控制点的高程拟合做了初步探讨。 相似文献
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作为"云控制"摄影测量理论和方法的发展,研究了DEM约束的立体卫星影像区域网平差方法。与DEM仅作为高程控制信息使用,或者是通过DEM表面匹配实现绝对定向的间接定位方法不同,DEM作为平高控制信息被直接引入至基于RFM模型的卫星影像区域网平差之中。本文方法将连接点地面高程与DEM格网内插高程之差作为虚拟观测值构建约束方程,不仅利用了DEM高程信息,并且利用了其地形曲面包含的平面信息,以"云控制"方式在区域网平差过程中有效消除卫星影像RPC参数中包含的整体偏移及区域网内部的扭曲变形,实现了无地面控制点条件下卫星影像平面及高程绝对定位精度的大幅提升。使用覆盖山东全境的330景天绘一号立体卫星影像进行试验,分别以AW3D30、ASTER GDEM和SRTM GL3共3种开源DEM作为控制信息,并使用100个外业实测控制点进行精度评测。试验表明,以DEM作为控制可显著提高区域网平差的平面与高程精度,卫星影像绝对定位精度与DEM自身精度有关。当使用AW3D30作为控制时,可以取得与使用100个外业控制点平差同等精度,平面中误差为5.0 m(约1像素),高程中误差为2.9 m。试验结果证明了DEM替代外业控制点作为平差控制信息的有效性与可行性。 相似文献
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随着GPS的引进推广与应用,大大缩短了控制测量的时间,提高了工作效率。由于城市大比例尺航测数字化成图法成图的需要,CPS必将代替以往繁杂的平高点的常规测量工序。 1994年国测二院承担了广州黄埔新港测区68Km~2的1∶500比例尺航测数字化成图方法的成图任务。平面控制点采用平高区域布设,用GPS测定,地面铺标、标志点。高程控制点采用全能法全野外布点,常规外业施测高程点。 相似文献
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经纬仪高程导线是航测外业中控制点高程联测的主要方法之一,在1:10000航测外业规范中对其测算及检查均有详尽的阐述。然而,起伏地区施测高程导线的实践表明,规范中的有关规定有待研究和修订补充。本文提出以下几点看法请读者指正。 相似文献
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低空无人机航测是当前我国测绘领域的研究与应用热点。在概述无人机航测外业和内业数据处理流程的基础上,进行了基于无人机航测数据的1∶2000DLG数据快速生产实践。经精度检验,成果数据影像分辨率、平面位置精度能满足1∶2000测图需求,而高程采用无人机POS系统自动解算结果。最后针对植被茂密区的高程数据如何获取和去除树高以及无控制测图提出了自己的思考。本文为偏远的茂密森林区快速获取大比例尺测图数据提供了方法,也能够为无人机航测在其他领域的应用提供参考。 相似文献
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《武汉大学学报(信息科学版)》2021,(10)
提高稀少甚至无地面控制点的区域网平差精度,是实现境外和外业测控困难区域高精度测图的核心问题之一,也是主要的技术难点。为了充分利用高分七号激光测高数据与立体影像同步获取、相对精度较高、高程精度极高的特点,充分发挥足印影像作用,提出了一种激光测高数据辅助的高分七号卫星立体影像区域网平差方法。通过足印影像实现了激光高程控制点在立体影像上的自动量测,利用其极高的高程精度对区域网立体影像进行高程控制,经过联合区域网平差实现区域网影像高程精度提升。通过覆盖不同地形类型的山东测区激光测高数据与立体影像联合平差实验表明,仅使用激光测高数据作为高程控制,实验区高程中误差可由原始7.97 m提高到0.79 m,高程最大误差优于1.5 m,高程精度改善明显。 相似文献
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Photogrammetric and laser altimetric reconstruction of water levels for extreme flood event analysis 总被引：1，自引：0，他引：1
Stuart N. Lane Timothy D. James Hamish Pritchard Mark Saunders 《The Photogrammetric Record》2003,18(104):293-307
This paper assesses the feasibility of estimating water levels using digital photogrammetry. A common problem during an extreme flood event is that automated water level recorders do not record the highest water levels, as a result of instrument malfunctioning. This paper explores two possible solutions to this problem based upon data acquired using synoptic remote sensing methods. The first method requires: (a) high-resolution elevation data (for example, in the form of a digital elevation model for the floodplain); and (b) information on the planimetric position of the maximum flood extent, such as from debris lines (known as wrack lines) visible on aerial imagery flown after the event. The planimetric data can then be used to segment the topographic data in order to identify water level elevations. The second method uses a digitial photogrammetric approach and is suitable where no topographic data are available, but aerial imagery is available, flown after the event. Provided this imagery is of the right scale, digital photogrammetric analysis may be used to identify the elevations of wrack lines visible on the imagery. In this paper, the second of these options is compared with the first. The research shows that desktop photogrammetric methods, using 1:4500 scale imagery, can yield water level estimates that are precise to ±0·147 m, on the basis of check data obtained from lidar data. This is a worst possible estimate of the acquired precision given uncertainties in the lidar data. When compared with the first option, based upon segmenting lidar data using flood outlines, the photogrammetric approach was found to be preferable given both the quality of the lidar and uncertainties over how to segment it. 相似文献
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This paper discusses the use of near vertical aerial photographs archived onto Kodak Photo CD in the production of a digital elevation model of the Isle of May, Scotland. Control for the survey was obtained using differential GPS receivers and the photogrammetric processing was carried out using low cost PC hardware and software. The elevation model is being used in a GIS to enable the spatial analysis of the island's seal population. 相似文献
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利用小型低空航摄平台和非量测小相幅相机,搭载动态GNSS/INS组合系统进行空三加密,研究无人机搭载GNSS/INS辅助在不同分辨率、不同基线数量条件下的像控点布设以及空三加密,并对其平面精度、高程精度进行分析,以实现利用少量地面控制点进行大比例尺地形图测图。 相似文献
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Using a multidisciplinary project studying surging glaciers in Svalbard as a reference, this paper examines some of the ways in which photogrammetry can be used as a research tool by glaciologists. Photogrammetric compilations of two of the glaciers under study were produced from 1990 aerial photography. Photogrammetry was regarded primarily as a source of digital elevation models in this project, rather than as a cartographic tool. Problems encountered in applying photogrammetry to the arctic terrain are considered and a methodology devised to ameliorate these problems by maximizing the available data is described. The results of the photogrammetric work are presented and difficulties in quantifying the accuracy of the photogrammetric data are examined. Examples of the ways in which the photogrammetrically derived digital data have been used for glaciological analysis and visualization are discussed. 相似文献
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Evaluation of Lidar and Medium Scale Photogrammetry for Detecting Soft-Cliff Coastal Change 总被引：3，自引：0，他引：3
Lidar and photogrammetry have both been evaluated for detecting shortterm coastal change using the Black Ven mudslide, Dorset as a case study. A lidar-generated digital elevation model (DEM) was obtained and initially compared with a DEM generated using available 1:7500 scale aerial photography and automated digital photogrammetry. The quality of these two data sets was assessed using a third DEM, derived using a total station and conventional ground survey methods. The vertical accuracies (rms error) of the lidar and photogrammetry were 0.26m and 0.43m respectively, although both data sets displayed a tendency to generate heights slightly lower than the elevation of the terrain surface. The quality of the two data sets was then assessed with respect to local slope angle. The accuracy of photogrammetrically derived elevations varied with slope and more so than in the case of lidar
From these basic tests, lidar has proved to be more accurate than photogrammetry for soft-cliff. monitoring. Further research is required to establish whether this trend is applicable to other data sets and specifically for photogrammetric data acquired using larger scale imagery 相似文献
From these basic tests, lidar has proved to be more accurate than photogrammetry for soft-cliff. monitoring. Further research is required to establish whether this trend is applicable to other data sets and specifically for photogrammetric data acquired using larger scale imagery 相似文献
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通过分析航空摄影测量规范和像点位移误差对航测成图精度的影响,认为造成这一问题的主要原因是我国航空摄影测量规范没有对像点位移误差做出相应的合理限制,而由像点位移误差导致的。 相似文献
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新疆伊犁河谷土地开发整理现状图测绘由于其作业范围广,精度要求高,采用了ADS 40数字航空摄影数据。本文主要阐述了基于ADS 40数据进行航测外业和内业完成伊犁河谷4 000 km2的现状图测绘的生产过程。 相似文献
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谭金石 《测绘与空间地理信息》2021,44(1):28-31
介绍了A3航空摄影测量系统的构成、成像方式及原理,并将其与常规航空摄影测量系统进行多方面比较分析。具体的工程实验表明,A3在航空影像获取、数据处理,生产高质量、高精度的数据产品等方面具有显著的优势,对后续的工程应用与研究具有一定的借鉴意义。 相似文献