Creating of Digital Surface Model and Orthophoto from ASTER Satellite Data and their Application in Land/Water Research (original) (raw)
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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.
Accuracy Analysis of Dems Derived from Aster Imagery
ASTER acquires along track stereoscopic imagery, with a spatial resolution of 15 meters. Automatic generation of Digital Elevation Models (DEMs) from these images is a well established process, implemented in many commercial software packages. It can provide relief information for areas with poor coverage of topographic mapping. This paper presents a study of the accuracy achieved in DEMs extracted from ASTER, for an area in Portugal, using the PCI OrthoEngine software. Images were orientated with ground control points (GCP) obtained from topographic maps. Experiments were carried out in reducing the number of GCPs. A number of 5 or 6 GCPs was always required to orient the images, in order to keep the accuracy achieved with larger numbers of points. It was possible to conclude that more use could have been done of the approximate orientation provided in the image header. A grid of points derived from the sensor position and attitude, estimated by onboard equipment, is given in the i...
DTMs generation from satellite stereo images: accuracy tests in mountain region
2004
Digital Terrain Models (DTM) represent an effective tool for many applications and in particular for terrain morphology investigation and orthoimages generation. The availability of satellite stereo images allows to generate updated DTMs through digital photogrammetric algorithms especially in those areas where old and poor maps exist. In this work we show some quality tests results about DEMs obtained from ASTER
DSM extraction from IKONOS and EROS A stereo imagery: methodology, accuracy and problems
The goal of this work was to evaluate the mean accuracy and its dependency on morphology and land cover types of the digital surface models (DSMs) extracted from IKONOS-II and EROS-A highresolution satellite in-track stereo imagery. DSMs were generated by the software PCI Geomatica OrthoEngine v. 9.0, which implements the well-known 3D rigorous (physical) model developed at the Canada Centre for Remote Sensing, Natural Resources Canada (CCRS). The paper illustrates the encountered problems and the achieved results during three experiments regarding two stereo IKONOS-II panchromatic images (with a small overlapping) of the Pozzuoli area (Naples, Southern Italy) and one stereo EROS-A image of the Tivoli area (Rome, Central Italy). Ground control points (GCPs) were collected by GPS: in the Pozzuoli area 29 GCPs were rapid-static surveyed with a mean 3D accuracy of 0.2-0.3 m; in the Tivoli area 23 GCPs with a mean 3D accuracy of 0.1 m were collected by RTK survey assisted by the GPS permanent network of the Lazio Region, managed by the Area di Geodesia e Geomatica-Università di Roma "La Sapienza". Three types of comparison were carried out when possible, in order to assess both mean accuracy and its dependency on morphology and land cover types: sample comparison, based on significant numbers of Independent Check Points (ICP) with a mean 3D accuracy of 0.3-0.5 m collected by kinematic GPS surveys; local and global comparisons with DEM generated from available maps, considering both contour lines and single points with photogrammetric derived heights; in this last respect, local comparisons were especially devoted to evaluate the accuracy dependency on morphology and land cover types (residential areas, dense forests, volcanic craters, bare soils, lakes, sea shoreline, Travertino quarries). A mean sample accuracy (RMS) of 1.9 and 6.0 m were achieved for IKONOS-II and EROS-A respectively. It has to be underlined that mean accuracy decreases remarkably in residential areas and forests, so that it is supposed that the intrinsic accuracy is better represented by the results obtained on bare soil and lakes, where RMS of 1.9 and 5.0 m were achieved for IKONOS-II and EROS-A respectively. The poorer results for EROS-A are probably mainly due to its asynchronous acquisition mode and to the extremely critical radiometric situation occurring on Travertino quarries, which appear almost uniformly white. Concerning the DEM/DSM classification criteria established by the Technical Steering Committee of the Italian State-Region Conference for GIS under the direction of O. Köebl, IKONOS-II derived DSMs have a quality at level 2-3, EROS-A at level 1-2.
MORPHOLOGIC QUALITY OF DSMs BASED ON OPTICAL AND RADAR SPACE IMAGERY
Digital Surface Models (DSMs) are representing the visible surface of the earth by the height corresponding to its X-, Y-location and height value Z. The quality of a DSM can be described by the accuracy and the morphologic details. Both depend upon the used input information, the used technique and the roughness of the terrain. The influence of the topographic details to the DSM quality is shown for the test fields Istanbul and Zonguldak. Zonguldak has a rough mountainous character with heights from sea level up to 1640m, while Istanbul is dominated by rolling hills going up to an elevation of 435m. DSMs from SPOT-5, the SRTM C-band height models and ASTER GDEM have been investigated. The DSMs have been verified with height models from large scale aerial photos being more accurate and including morphologic details. It was necessary to determine and respect shifts of the height models caused by datum problems and orientation of the height models. The DSM quality is analyzed depending upon the terrain inclination. The DSM quality differs for both test fields. The morphologic quality depends upon the point spacing of the analyzed DSMs and the terrain characteristics.
Aster Digital Elevation Model and orthorectified images generated on the GEO Grid
2010 IEEE International Geoscience and Remote Sensing Symposium, 2010
(AIST) developed an on-demand processing service on the GEO Grid system [1] to generate a Digital Elevation Model and orthorectified images from an ASTER data [2]. It is designed to support the latest algorithms for radiometric and atmospheric corrections developed by researchers as well as the geometric correction and other DEM processing options. The functions and options in this service are developed and implemented as modules, so that they can be arranged as the user requires. Although the system is an experimental, it can provide higher quality data sets than the standard products. In this paper, we present an overview of ASTER DEM and orthoimage data set (ASTER Data BETA).
Airborne pushbroom systems for the direct acquisition of digital imagery enable the simultaneous capture of high quality 3D and multispectral information of a scene. The combination of geometric and radiometric information should improve tasks like DTM generation-usually solely based on stereo imagery-and landuse classification, which is traditionally restricted to the interpretation of spectral information. Within this paper these assumptions are confirmed utilizing datasets of the DPA (Digital Photogrammetric Assembly), a scanning airborne sensor which records simultaneously high spatial resolution stereo and multispectral image. Since the surface reconstruction and ortho image generation from airborne scanner imagery, which is a prerequisite for the proposed approach is different to standard procedures using full frame images, this process will be described in the first part of the paper. Afterwards the benefits of a combined evaluation of stereo and multispectral data will be demonstrated for two tasks, the generation of Digital Terrain Models and the landuse classification for thematic mapping.
Int. Journal of Advances in Remote Sensing and GIS, 2016
Abstract: A Digital Elevation Model (DEM) is a representation of a land surface in a 3 dimensional space with elevation as the third dimension along X (horizontal coordinates) and Y (vertical coordinates) dimensions. DEM is a useful data source in hilly areas terrain analysis; DEM plays an important role in various areas like disaster management, hydrology and watershed management, geomorphology, urban development, map creation and resource management etc. Cartosat 1 or IRS P5 (Indian Remote Sensing Satellite) is a state of the art remote sensing satellite developed and launched by ISRO (May 5, 2005). It has been designed for terrain modeling and large scale mapping applications. This high resolution stereo data has great potential to produce high quality DEM. The high resolution Cartosat 1 stereo image data is capable to provide significant impact in topographic mapping and watershed applications. The objective of the present study is to generate high resolution DEM (10 m and 30 m) and ortho rectified image through Cartosat 1 stereo pair, quality evaluation in different elevation strata, generation of terrain parameters. Aglar watershed in Tehri Garhwal and Dehradun district has been used as the test site. The present study reveals that DEM generated (10 m and 30 m) using CARTOSAT 1 stereo pair is of high quality. The derived terrain parameters like slope, aspect, drainage, watershed boundaries etc., are also of good quality. A comparison of the DEM and the parameter derived from it reveals significant improvement in the quality as compared to the freely available DEM in internet. Keywords: ASTER DEM, CARTO DEM, CARTOSAT 1, Digital Elevation Model, Ortho rectified Image, Photogrammetry, Rational Polynomial Coefficient, Stereo Pair, Terrain Parameters.
Accuracy Assessment of Different Digital Surface Models
ISPRS International Journal of Geo-Information
Digital elevation models (DEMs), which can occur in the form of digital surface models (DSMs) or digital terrain models (DTMs), are widely used as important geospatial information sources for various remote sensing applications, including the precise orthorectification of high-resolution satellite images, 3D spatial analyses, multi-criteria decision support systems, and deformation monitoring. The accuracy of DEMs has direct impacts on specific calculations and process chains; therefore, it is important to select the most appropriate DEM by considering the aim, accuracy requirement, and scale of each study. In this research, DSMs obtained from a variety of satellite sensors were compared to analyze their accuracy and performance. For this purpose, freely available Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) 30 m, Shuttle Radar Topography Mission (SRTM) 30 m, and Advanced Land Observing Satellite (ALOS) 30 m resolution DSM data were obtained. Additionally, 3 m and 1 m resolution DSMs were produced from tri-stereo images from the SPOT 6 and Pleiades high-resolution (PHR) 1A satellites, respectively. Elevation reference data provided by the General Command of Mapping, the national mapping agency of Turkey-produced from 30 cm spatial resolution stereo aerial photos, with a 5 m grid spacing and ±3 m or better overall vertical accuracy at the 90% confidence interval (CI)-were used to perform accuracy assessments. Gross errors and water surfaces were removed from the reference DSM. The relative accuracies of the different DSMs were tested using a different number of checkpoints determined by different methods. In the first method, 25 checkpoints were selected from bare lands to evaluate the accuracies of the DSMs on terrain surfaces. In the second method, 1000 randomly selected checkpoints were used to evaluate the methods' accuracies for the whole study area. In addition to the control point approach, vertical cross-sections were extracted from the DSMs to evaluate the accuracies related to land cover. The PHR and SPOT DSMs had the highest accuracies of all of the testing methods, followed by the ALOS DSM, which had very promising results. Comparatively, the SRTM and ASTER DSMs had the worst accuracies. Additionally, the PHR and SPOT DSMs captured man-made objects and above-terrain structures, which indicated the need for post-processing to attain better representations.