GENERATION AND VALIDATION OF HIGH-RESOLUTION DEMS FROM WORLDVIEW-2 STEREO DATA (original) (raw)

Metric Accuracy of Digital Elevation Models from WorldView-3 Stereo-Pairs in Urban Areas

Remote Sensing

WorldView-3 satellite is providing images with an unprecedented combination of high spatial and spectral resolution. The stereo capabilities and the very high resolution of the panchromatic band (0.31 m) have been fostering new applications in urban areas, where the complexity of the morphology requires a higher level of detail. The present technical note aims to test the accuracy of digital elevation models that can be obtained by WorldView-3 stereo-pairs in these particular contexts, with an operational state-of-the-art algorithm. Validation is performed using check points and existing models of the area (from LiDAR data and oblique aerial images). The experiments, conducted over the city of Bologna (Italy) with six images, proved that roof surfaces and open spaces can be reconstructed with an average error of 1–2 pixels, but severe discrepancies frequently occur in narrow roads and urban canyons (up to several metres in average). The level of completeness achievable with only one...

Evaluation of Digital Elevation Models Derived from Multi-Date Satellite Stereo Imagery for Urban Areas

GI_Forum, 2021

High-resolution digital elevation models of urban areas can support humanitarian organisations in their work; especially the 3D reconstruction of buildings is desirable because it can be used for population estimation and damage analysis after crises and disaster events. In this paper, we test the quality of multi-date DEMs with 15 Pléiades images from Port-au-Prince, Haiti using the automatic stereo pipeline s2p. We focus on triplet combinations with images taken from different dates. This study investigates the metaparameters satellite azimuth and incident angle to understand which recording geometry yields a good result in terms of completeness and accuracy. It is assumed that the closer the multi-date constellation gets to an in-orbit triplet, the better the quality of the DEM.

Benchmarking and quality analysis of DEM generated from high and very high resolution optical stereo satellite data

2010

The Working Group 4 of Commission I on “Geometric and Radiometric Modelling of Optical Spaceborne Sensors” will provide on its website several stereo data sets from high and very high resolution spaceborne stereo sensors. Among these are data from the 2.5 meter class like ALOS-PRISM and Cartosat-1 as well as, in near future, data from the highest resolution sensors (0.5 m class) like GeoEye-1 and Worldview-1. The region selected is an area in Catalonia, Spain, including city areas (Terrassa), rural areas and forests in flat and medium undulated terrain as well as steep mountainous terrain. In addition to these data sets, ground truth data like orthoimages from airborne campaigns and Digital Elevation Models (DEM) produced by laser scanning, all data generated by the Institut Cartografic de Catalunya (ICC), are provided as reference for comparison. The goal is to give interested scientists of the ISPRS community the opportunity to test their algorithms on DEM generation, to see how t...

Refinement of urban digital elevation models from very high resolution stereo satellite images

ISPRS. IPI-Workshop, 2009

Digital elevation models (DEM) of high resolution and high quality are required for many applications like urban modeling, readiness for catastrophes or disaster assessment. A good source for the derivation of such DEMs from any place in the world are very high resolution (VHR) satellite stereo images as provided e.g. by Ikonos, QuickBird or WorldView. In this paper a method for the generation and refinement of urban high resolution DEMs from VHR imagery is presented and evaluated. Urban DEMs generated from very high resolution satellite imagery of ground sampling distances of about one meter are normally of resolutions of about three to ten meters. For the above mentioned applications of urban DEMs such results are often too coarse. In this paper an advanced method for the generation of dense digital elevation models is presented and discussed. The method is mainly based on dense stereo algorithms developed for computer vision applications. It is adapted and optimized to earth observation requirements. In the paper the DEM generation together with the additional refinement steps is presented and evaluated using very high resolution stereo imagery from Munich and Athens. The generated DEMs are compared to ground truth data where available and the quality and efficiency of the algorithms are analyzed and discussed.

Generation and analysis of Digital Elevation Model (DEM) using Worldview-2 stereo-pair images of Gurgaon district: A geospatial approach

2017

The use of very high resolution satellite images in photogrammetric tasks is increasing continuously, especially in tasks such as Digital Elevation Models (DEM) generation or ortho-images production. A large number of new photogrammetric uses of Earth Observation data appear due to improvement of the geometric accuracy of the products. Elevation data can be represented as raster DEM (a grid of squares or rectangles) or as a triangular irregular network or as contours. The present study focuses on the generation of DEM and contours of the study area using Worldview-2 stereo pair imagery (with spatial resolution of 0.5 meter). The contours are generated at 5 meter vertical interval. The methods applied in this study are a linear polynomial correction using 3-Dimensional ground control points (GCPs), rational polynomial coefficient (RPC) correction without refinement and RPC correction with linear refinement using 3D GCPs. The GCPs were collected by means of differential global positio...

Assessment of DEM derived from very high-resolution stereo satellite imagery for geomorphometric analysis

European Journal of Remote Sensing

Very high-resolution satellite stereo images play an important role in cartographical and geomorphological applications, provided that all the processing steps follow strict procedures and the result of each step is carefully assessed. We outline a general process for assessing a reliable analysis of terrain morphometry starting from a GeoEye-1 stereo-pair acquired on an area with different morphological features. The key steps were critically analyzed to evaluate the uncertainty of the results. A number of maps of morphometric features were extracted from the digital elevation models in order to characterize a landslide; on the basis of the contour line and feature maps, we were able to accurately delimit the boundaries of the various landslide bodies.

Performance evaluation of global and absolute DEMs generated from ASTER stereo imagery

2011

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital stereo image could be used to generate Digital Elevation Model (DEM), which represents the terrain elevation in discrete three dimensional (3D) forms. In this research, the performance of the absolute and Global DEMs generated from ASTER stereo image is evaluated for the area of Universiti Teknologi Malaysia (UTM). In doing so, 25 Ground Control Points (GCPs) collected by Global Positioning System (GPS) instrument are used to extract an absolute ASTER DEM. Furthermore, the ASTER Global DEM (GDEM) is acquired for the study area. The accuracy of the DEMs is assessed by comparing them with 20 high accuracy points which were collected using GPS technology. Some statistical parameters such as the Mean Error (ME), Standard Deviation (SD) and Root Mean Square Error (RMSE) are determined for this purpose. The achieved results indicated that the estimated vertical accuracy of the ASTER GDEM is less than 5 m at 80% confidence for the study area while the vertical accuracy of less than 15 m is obtained for the ASTER absolute DEM, which is less than the pixel size of ASTER image. Finally, according to the achieved results, 15 m resolution of ASTER image and the selected number of check points, it can be concluded that the accuracy of DEMs is acceptable for the study area, and could be used for various geoinformation applications.

Generation and quality assessment of stereo-extracted DSM from geoeye-1 and worldview-2 imagery

IEEE Transactions on Geoscience and Remote Sensing, 2014

Digital surface models (DSMs) extracted from 15 different stereo pairs attained by the combination of GeoEye-1 (GE1) and WorldView-2 (WV2) panchromatic very high resolution (VHR) satellite images are tested. Two of them are pure same-date along-track stereo pairs, one from each VHR satellite, whereas the rest are mixed multidate across-track ones. A quality assessment on the DSMs extracted from the aforementioned stereo pairs, involving both accuracy and completeness, is carried out. Several factors are tested such as sensor model used in the bundle adjustment, number of ground control points (GCPs), radiometric characteristics, satellite imaging geometry, time between acquisition dates, and target land cover. A highly accurate light detection and ranging elevation data is used as ground truth. Overall, 3-D rational functions refined by a zero-order polynomial adjustment by using 7 or 12 GCPs performed slightly better regarding both DSM vertical accuracy and completeness. In relation to the pure stereo pairs, the DSM extracted from the GE1 stereo pair attained better vertical accuracy over the whole study area (90th percentile linear error, LE90, of 2.04 m) but lower completeness (74.50%) than the WV2 one (2.56 m and 83.35%, respectively). The undergoing hypothesis is that the blurrier images from WV2 could have influenced in the improvement of the matching success rate while reducing the vertical accuracy of extracted points. When all the 15 stereo pairs are considered, the vertical accuracy mainly depends on the convergence angle. In addition, the temporal difference between acquisition dates turned out to be the most influential factor regarding completeness values.

Designing high resolution countrywide DEM for Turkey

International Journal of Engineering and Geosciences, 2018

Digital Elevation Models (DEM) are widely used in many different applications such as orthophoto production, 3D city models, hydrological modeling, visibility, flood, flood analysis and etc. The densest grid spacing DEM covering Turkey is the DTED-2 data produced by the General Command of Mapping with a grid spacing of 1 second (approximately 30 m). Denser and more accurate DEM is produced by several institutions in only required areas but not covering whole country. Governmental institutions need denser, more accurate, homogeneous and countrywide DEM. This study is conducted to meet DEM demands with optimum accuracy and density by stereo aerial photos. In order to investigate the optimal resolution for a countrywide DEM, test DEMs are produced in three different areas representing the general topographic structure of Turkey by using 45 cm ground sampling distance stereo aerial photos. The Root Mean Square Error (RMSE) of the heights of three areas are respectively ± 2.51 m, ± 1.38 ...

DEM Accuracy of High Resolution Satellite Images

Lecture Notes in Computer Science

The aim of this research is to study the accuracy of Digital Elevation Models (DEMs) generated from two different satellite data namely OrbView-3 and IKONOS stereo images. 21 GCPs (Ground Control Points), 182 CPs (Check Points) and selected transects representing different land covers and topography were used for the accuracy analysis. Two DEMs were generated from OrbView-3 and one DEM from IKONOS stereo data. The accuracy of the used model for DEM generation was quantified using the RMSE (Root Mean Square Error) values of GCPs derived from Global Positioning System survey and error analysis over research area was performed using 182 CPs derived from traditional field survey. Several transects were formed over different parts of the study area and height values along these transects obtained from different DEMs were compared to determine and examine the accuracy. The results are analyzed with the empirical accuracy criterion for heights on analog maps.