Creation and Evaluation of Digital Elevation Models from Ground Surveying Measurements (original) (raw)
Related papers
A comparision of interpolation methods for producing digital elevation models at the field scale
Earth Surface Processes and Landforms, 2009
Digital elevation models have been used in many applications since they came into use in the late 1950s. It is an essential tool for applications that are concerned with the Earth's surface such as hydrology, geology, cartography, geomorphology, engineering applications, landscape architecture and so on. However, there are some differences in assessing the accuracy of digital elevation models for specific applications. Different applications require different levels of accuracy from digital elevation models. In this study, the magnitudes and spatial patterning of elevation errors were therefore examined, using different interpolation methods. Measurements were performed with theodolite and levelling. Previous research has demonstrated the effects of interpolation methods and the nature of errors in digital elevation models obtained with indirect survey methods for small-scale areas. The purpose of this study was therefore to investigate the size and spatial patterning of errors in digital elevation models obtained with direct survey methods for large-scale areas, comparing Inverse Distance Weighting, Radial Basis Functions and Kriging interpolation methods to generate digital elevation models. The study is important because it shows how the accuracy of the digital elevation model is related to data density and the interpolation algorithm used. Cross validation, split-sample and jack-knifing validation methods were used to evaluate the errors. Global and local spatial auto-correlation indices were then used to examine the error clustering. Finally, slope and curvature parameters of the area were modelled depending on the error residuals using ordinary least regression analyses. In this case, the best results were obtained using the thin plate spline algorithm.
2014
Light Detection and Ranging (LiDAR) is a recently established remote sensing technology, however its capabilities have not been fully exploited. Airborne Laser Scanning (LiDAR) is characterized by high density of point measurements that can be utilized in creation of digital elevation model (DEM) with levels centimetre accuracy. Since LiDAR measurements are always in discrete point data format, there is always a need for interpolation operations in order to create a continuous surface forming a DEM. As different interpolation techniques are expected to provide different quality DEMs it has been important to analyze the outcomes from those techniques. This research is focused towards evaluation of DEMs generated from raw airborne LiDAR measurements in bare lands using the Inverse Distance Weighting (IDW) and the spline interpolation approaches. A sample of raw LiDAR data for Gilmer county, USA has been exploited in the study. Digital elevation models have been generated from the data...
2009
GIS (Geographical Information System) is one of the most striking innovation for mapping applications supplied by the developing computer and software technology to users. GIS is a very effective tool which can show visually combination of the geographical and non-geographical data by recording these to allow interpretations and analysis. DEM (Digital Elevation Model) is an inalienable component of the GIS. The existing TM (Topographic Map) can be used as the main data source for generating DEM by amanual digitizing or vectorization process for the contours polylines. The aim of this study is to examine the DEM accuracies, which were obtained by TMs, as depending on the number of sampling points and grid size. For these purposes, the contours of the several 1/1000 scaled scanned topographical maps were vectorized. The different DEMs of relevant area have been created by using several datasets with different numbers of sampling points. We focused on the DEM creation from contour line...
Impact of interpolation techniques on the accuracy of large-scale digital elevation model
Open Geosciences
There is no doubt that the tremendous development of information technology was one of the driving factors behind the great growth of surveying and geodesy science. This has spawned modern geospatial techniques for data capturing, acquisition, and visualization tools. Digital elevation model (DEM) is the 3D depiction of continuous elevation data over the Earth’s surface that is produced through many procedures such as remote sensing, photogrammetry, and land surveying. DEMs are essential for various surveying and civil engineering applications to generate topographic maps for construction projects at a scale that varies from 1:500 to 1:2,000. GIS offers a powerful tool to create a DEM with high resolution from accurate land survey measurements using interpolation methods. The aim of this research is to investigate the impact of estimation techniques on generating a reliable and accurate DEM suitable for large-scale mapping. As a part of this study, the deterministic interpolation al...
ACCURACY ACCESSMENT & COMPARISON OF DEM INTERPOLATION TECHNIQUES IN GIS
DEM (Digital Elevation Model) interpolation techniques are approaches used to predict elevation values at unsampled points, improving the accuracy and completeness of the terrain representation. The precision of the generated terrain model relies on the chosen interpolation method, so it is essential to evaluate and compare the effectiveness of various interpolation techniques. This report presents an accuracy assessment and comparison of various DEM interpolation techniques within a GIS (Geographic Information System) framework. The study aims to evaluate the performance of six interpolation methods: Natural Neighbor, Inverse Distance Weighting (IDW), Spline, ANUDEM, Triangulated Irregular Network (TIN), and Kriging. The project was conducted using spatial data from Thaha Municipality, with the primary objective of determining the most accurate interpolation technique for this area. The methodology involved data acquisition, preprocessing, and implementation of the interpolation techniques, followed by error assessment using statistical measures such as Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). The results indicate that TIN was the most accurate method, followed closely by Natural Neighbor and Kriging. ANUDEM and IDW exhibited moderate accuracy, while Spline showed the highest errors and the lowest model fit. This study provides valuable insights into the selection of appropriate DEM interpolation techniques for different terrains and data characteristics, contributing to improved accuracy in spatial analyses and decision-making processes in geomatics engineering.
Investigation of Sampling and Interpolation Techniques for DEMs Derived from Different Data Sources
2005
The Digital Elevation Model (DEM) is an important part of mapping technology. It is used for several purposes including contours derivation, geometric correction of photogrammetric and remote sensing images and Geographic Information System (GIS) applications. There are different procedures and techniques for collecting the data to generate DEMs. These techniques include digitizing contour maps, direct field observations using ground surveying methods, photogrammetric and remote sensing procedures and recently by Global Positioning System (GPS) and laser profiling and laser scanning. Interpolation is often required to create DEM from sparse number of points. In this paper the interpolation accuracy of four methods namely: 1) Inverse distance to a power, 2) Kriging, 3) Radial basis function and 4) Triangulation with linear interpolation are investigated. The investigation was practically performed using GPS and Total Station observations of the same test area for comparative purposes...
Evaluation of methods for digital elevation model interpolation of tillage systems
There are very little attempts of DEM evaluation in such a disturbed or discontinuous surface (e.g., in tillage area). Present study aims to evaluate common interpolation methods (triangulation, nearest neighbor, natural neighbor, minimum curvature, multiquadratic radial basis function (MRBF), ordinary kriging, and inverse distance weight) in representing the detail topography of two different tillage types, namely bench terrace and furrow. Evaluation procedure was conducted through a stepwise analysis by using combination between the accuracy level (coefficient of determination (R 2), mean error (ME) and standard deviation error (S)) and the shape similarity analysis. This study also shows the application of break-line function during the interpolation process in order to optimize some interpolation methods and the usage of drainage sink area as another step in evaluating DEM quality. To achieve the aim of this study, two field-size of dry-land agriculture (tegalan) were observed by using a set of total station Nikon DTM 322 with 3" angle accuracy. These plots, namely Tieng (1652 m²) and Buntu (673 m²), are situated in the upper part of Wonosobo District, Central Java Province, Indonesia. Tieng plot represents the bench terrace system embedded with stones on its terrace risers and showing relatively smooth ground surface. On the other side, Buntu plot shows the ridges and furrows system that lays perpendicularly to the contour lines. In terms of R², ME and S, there were slight differences in results between each method, except the multiquadratic radial basis function which was failed to generate terrace form in Tieng. The final result shows that triangulation is the best fit method followed by natural neighbour at representing the bench terraces in Tieng plot. In the case of furrow in Buntu plot, natural neighbour is the most accurate method. Despite its superiority at representing the bench terrace, triangulation has larger sink drainage area compared to natural neighbour. This study has confirmed the robustness of a stepwise analysis between quantitative and qualitative assessment techniques for DEM accuracy. A fine value of quantitative parameter does not necessarily mean that it will fairly possess a good spatial accuracy. Detain topography Digital elevation model Interpolation Tillage systems
2014
ABSTARCT Ground surveying methods are main sources for digital elevation data that is usually utilized in the creation of a Digital Elevation Model (DEM). DEM usually is a main input in many Engineering and Environmental applications. The quality of the DEM is a vital issue that controls the qualities of outputs in different applications. Different factors including the data source, the data density, the sampling method, the spatial resolution and the interpolation scheme control the quality of the DEM. This research is focused towards investigating the effects of the spatial resolution of the DEMs generated from ground surveying data on their qualities where digital elevation data has been collected from a test area of corrugated terrain using ground surveying methods. Qualitative and quantitative analyses have been applied on DEMs created from digital elevation data with different resolutions through; visual analysis, statistical analysis, profile analysis and finally accuracy ass...
Generation and Accuracy Assessment of Digital Elevation Models in Mountain Area
2015
Nowadays DEMs are indispensable tools in studies and analysis regarding Earth’s surface. Generating DEMs closely to the true surfaces and with high accuracy represent a main issue. The aim of the study is to improve the geomorphometric analysis based on DEMs. In this study a statistical approach was used to assess various DEMs generated with different methods to compare their accuracy. DEMs were created on the base of a topographic map using classical interpolation methods (Spline, IDW, Kriging, Simple linear interpolation) and simulated surfaces. The results suggest that data source is more important in error propagation, followed by interpolation methods.