Do you want to publish a course? Click here

Accuracy of interpolation methods for the derivation of digital elevation models based on gridding observations

دقة طرق الاستيفاء في إنتاج النماذج الارتفاعية الرقمية من قياسات شبكية حقلية

1528   2   52   0 ( 0 )
 Publication date 2017
and research's language is العربية
 Created by Shamra Editor




Ask ChatGPT about the research

In this study, we focused on the interpolation methods for the derivation of digital elevation models, based on field gridding observations with different spacing.

References used
AGUILAR, F and et al 2005 Effects of Terrain Morphology, Sampling Density, and Interpolation Methods on Grid DEM Accuracy, Photogrammetric Engineering and Remote Sensing, 71(7).805-816
CARTER, J.R 1988 Digital representations of topographic surfaces, Photogrammetric Engineering and Remote Sensing, 54(11).1577–1580
CHAPLOT, V DARBOUX, F BOURENNANE, H LEGUÉDOIS, S SILVERA, N PHACHOMPHON, K 2006 Accuracy of interpolation techniques for the derivation of digital elevation models in relation to landform types and data density, Geomorphology ,77(1). 126-140
rate research

Read More

In this paper, we describe an algorithm to register the retinal images by employing a relatively cross-correlation function. Pixel to pixel accuracy has been investigated and evaluated among registered images by calculating the local cross-correla tion between extracted vessels profiles along tracked vessels after transforming the images into alignment.
This research aimed for using Geographic Information System (GIS) in producing Digital Elevation Model (DEM) for Dimas District, By applying various methods: Spatial Analyst, Geo Statistical Analyst, Triangulated Irregular Network (TIN), and interp olating DEM from contour lines. The study showed that the best methods for interpolating DEM is Kriging method, Which interpolated an evaluated surface for scattered points which had (Z values) whether they were closed or scattered from each other. And (TIN) method which required less area on hard disc to be stored comparing with other methods, and it's perfect for representing surfaces in wide areas, Also generating DEM from contour lines produced DEM which had very accurate representing for surfaces.
3D GIS can be realized as an actual building platform of the urban space. This research develops automated 3D urban models that fit large-scale digital photogrammetry. Originally, modeling used manual or semi-manual techniques, and there is a need to for a development of an approach that automates the transformation of vector linear data, optimized by digital photogrammetry stations to create the 3D volume model in 3DGIS. This approach consists of three main phases: roof modeling, wall modeling and volume structuring. During the first phase, local and conditional "Delaunay Triangulation" method is used to deal with the majority of roof types regardless of its geometry. The second phase is completely automated to create the walls by the vertical projection (Top-Down) of the outer line of the roof into the Digital Terrain Model (DTM), and then by the selection of the bottom base level as the default level. Finally, different elements of the structure can be aggregated using spatial relationships (many-to-many) already supported by GIS software. The new approach is created and completely automated. It doesn't require roof geometric-types library, which asserts the GIS is a valid platform to build, to view and to store 3D urban models.
International river basins are characterized by their wide extent where mapping earth surface features and drawing contours by topographic team become–somehow- impossible because the cost and efforts consumed to execute it become very high and may exceed reasonable limits. Here it becomes necessary to use digital elevation models (DEM) inferred by specialized scientific organizations using remote sensing. There are several DEMs available on the internet and downloadable for free. The primary factor in defining the models efficiency in building hydrological models not the least cost but the maximum reliable results and better resolution that adequate to the capabilities of the PCs. In this study, three DEMs were used to derive and build hydrological models for the Euphrates-Tigris basin using Geographic information system techniques. The resulted boundaries of Euphrates-Tigris basin were compared with three boundaries implemented by international research organizations (UNEP, ESCWA, and FAO). As a conclusion of this comparison, the SRTM—3arc DEM was the most efficient model among used models. In addition, this study indicated the necessity to reevaluate Basin’s boundaries and correct the spatial distribution of proportion for basin area between the riparian countries.
Deep learning models exhibit a preference for statistical fitting over logical reasoning. Spurious correlations might be memorized when there exists statistical bias in training data, which severely limits the model performance especially in small da ta scenarios. In this work, we introduce Counterfactual Adversarial Training framework (CAT) to tackle the problem from a causality perspective. Particularly, for a specific sample, CAT first generates a counterfactual representation through latent space interpolation in an adversarial manner, and then performs Counterfactual Risk Minimization (CRM) on each original-counterfactual pair to adjust sample-wise loss weight dynamically, which encourages the model to explore the true causal effect. Extensive experiments demonstrate that CAT achieves substantial performance improvement over SOTA across different downstream tasks, including sentence classification, natural language inference and question answering.
comments
Fetching comments Fetching comments
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا