Accuracy improvement of ASTER stereo satellite generated DEM using texture filter (original) (raw)
Related papers
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.
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...
Towards automated DEM generation from high resolution stereo satellite images
International Society for …, 2008
High resolution stereo satellite imagery is well suited for the creation of digital surface models (DSM). In this paper, a system for highly automated DSM and orthoimage generation based on CARTOSAT-1 imagery is presented. The proposed system processes photometrically corrected level-1 stereo scenes using the rational polynomial coefficients (RPC) universal sensor model. The RPC are derived from orbit and attitude information and have a much lower accuracy than the ground resolution of approximately 2.5 m. Ground control points are used to estimate affine RPC correction. Accurate GCP are not always available, especially for remote areas and large scale reconstruction. In this paper, GCP are automatically derived from lower resolution reference images (Landsat ETM+ Geocover and SRTM DSM). It is worthwhile to note that SRTM has a much higher lateral accuracy than the Landsat ETM+ mosaic, which limits the accuracy of both DSM and orthorectified images. Thus, affine RPC correction parameters are estimated by aligning a preliminary DSM to the SRTM DSM, resulting in significantly improved geolocation of both DSM and orthoimages. Robust stereo matching and outlier removal techniques and prior information such as cloud masks are used during this process. DSM with a grid spacing of 10 m are generated for 9 CARTOSAT-1 scenes in Catalonia. Checks against independent ground truth indicate a lateral error of 3-4 meters and a height accuracy of 4-5 meters. Independently processed scenes align at subpixel level and are well suited for mosaicing.
ACCURACY OF DEM GENERATION FROM TERRA-ASTER STEREO DATA
In this work we studied the accuracy of DEMs generated from ASTER stereoscopic images by automated stereo-matching techniques with two different softwares (OrthoBase PRO and OrthoEngine). We compare several DEMs generated for a test area of 23 km x 28 km situated in the province of Granada (south Spain). This is an area was selected because its variable and complex topography with elevations ranging from 300m up to 2800 m.
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...
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.
Use of Aerial and Satellite Imagery for DEM Extraction and GIS Applications
2020
Digital Object Identifier 10.32754/JMT.2019.1.06 37 12Abstract—This paper describes a workflow for digital terrain model extraction from aerial and satellite stereo imagery and its integration in GIS applications. The results obtained using aerial and satellite stereo scenes are presented and commented. Stereo scenes are oriented using an approximate model named parallel projection which is a model that gained popularity due to simplicity and precision. For the digital terrain model generation the points are automatically extracted in the images using a modified Harris correlation operator and their 3D coordinates are then calculated with parallel projection parameters. After the 3D surface generation the terrain model is used further for visibility analysis.
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system embarked on the Terra (EOS AM-1) satellite has been a source of stereoscopic images covering the whole globe at a 15m resolution at a consistent quality for over 15 years. The potential of this data in terms of geomorphological analysis and change detection in three dimensions is unrivaled and needs to be exploited. However, the quality of the DEMs and ortho-images currently delivered by NASA (ASTER DMO products) is often of insufficient quality for a number of applications such as mountain glacier mass balance. For this study, the use of Ground Control Points (GCPs) or of other ground truth was rejected due to the global " big data " type of processing that we hope to perform on the ASTER archive. We have therefore developed a tool to compute Rational Polynomial Coefficient (RPC) models from the ASTER metadata and a method improving the quality of the matching by identifying and correcting jitter induced cross-track parallax errors. Our method outputs more accurate DEMs with less unmatched areas and reduced overall noise. The algorithms were implemented in the open source photogrammetric library and software suite MicMac.
ASSESSMENT OF DEMS PRODUCED BY MEDIUM RESOLUTION OPTICAL SENSORS CONSIDERING LAND COVER CLASSES
A digital elevation model (DEM) presents immense data proving three dimensional terrain structure of any part of the Earth. DEMs are obtained by two main methods in space-borne remote sensing as stereoscopy using optical or radar imagery and interferometric synthetic aperture radar (InSAR) technology. In fact, the primary product of space-borne remote sensing techniques is a digital surface model (DSM) that contains points located on the top of ground objects. By removing these points that do not belong to the bare ground, the DEM is obtained. In optical imagery, DSMs are generated based on stereo matching using ground control points and co-located clear tie points at stereo image-pair with high correlation. In this case, correlation comes into prominence and affects the success of DSM acquired by stereoscopy. This investigation aims to assess the quality of DEMs produced by medium resolution spatial data derived from optical imagery depending upon the effect of correlation in stereoscopy correspondingly the land cover types. Towards this purpose, land cover classes have been generated such as open, forest, built-up, road network and rocky regions, DSM-DEM conversion was applied by optimal filtering methods and DEM accuracies have been achieved separately. The analyses were realized using actual ASTER GDEM Version 2 with 30m original grid spacing in Zonguldak, Turkey including rugged topography and suitable land cover classes. For the verification, a reference DEM derived from 1/1000 scaled aerial photos was employed.
Potential of Dense Matching for the Generation of High Quality Digital Elevation Models
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2011
Until recently, the acquisition of high quality Digital Elevation Models was dominated by the use of airborne LiDAR. However, the increasing quality of digital airborne cameras in combination with recent improvements in matching algorithms meanwhile allow for the automatic image based collection as a suitable alternative. Within the paper, these progresses will be demonstrated on the example of photogrammetric DEM generation using the Semi-Global Matching (SGM) stereo method. Since this approach aims at a pixel-wise matching, dense 3D point clouds can be generated. The tests described in the paper are based on data collected from different digital airborne cameras at various flight scenarios during a recent test on photogrammetric 3D data capture. By these means, the impact of different stereo configurations on the quality of the final outcome can be evaluated and compared to already available test results. Special interest is also paid to the analysis and combination of multiple stereo image pairs with different baseto-height ratios, which can be used efficiently to increase the accuracy and reliability of the matching result.