Hannes Raggam | Joanneum Research (original) (raw)
Papers by Hannes Raggam
As for any other remote sensing data, the geometric fidelity of Envisat ASAR image products is of... more As for any other remote sensing data, the geometric fidelity of Envisat ASAR image products is of interest to the user community. The Institute of Digital Image Processing is in charge to check and proof the geometric quality of Envisat products acquired in the ASAR image mode. This paper focusses on results, which have been achieved for a data set comprising IMP and IMM products, which represent the precision and the medium resolution mode, respectively, and which have been acquired over the Flevopolder test site. With regard to geometic validation, the a-priori location accuracy of the Envisat products is of particular relevance. As demonstrated through the validation tests, the ASAR products being investigated in general show a highly acceptable geometric performance and promise to be valuable fundamentals for geo-scientific applications. 1
Based on a first prototype, an improved low-cost aerial platform was developed at the Institute o... more Based on a first prototype, an improved low-cost aerial platform was developed at the Institute of Digital Image Processing in order to be used for immediate acquisition and processing of image data wherever necessary. Typically, such requirements arise in case of natural hazards, where the amount of environmental or infrastructural damage has to be rapidly assessed and quantified. In general, the platform comprises a camera as well as GPS and IMU instruments in order to record the position and orientation of the camera. Using a helicopter, first campaigns have been flown with this platform over various urban and sub-urban test sites in Vienna and Graz in order to map buildings, or – more generally- to create digital surface models. Ground control points were measured and used for these test sites to perform aero-triangulation via block adjustment, and to estimate and validate the potential accuracy with respect to 3D mapping. In this paper, pilot mapping applications are presented,...
For several years the technique of radargrammetry with high resolution Synthetic Aperture Radar (... more For several years the technique of radargrammetry with high resolution Synthetic Aperture Radar (SAR) data has been used in scientific and commercial environment for Digital Elevation Modelling (DEM). Compared to repeat pass interferometry, radargrammetry is a robust DEM generation technique for almost all areas on the globe due to phase independent matching algorithms. Particularly in areas with high cloud coverage, SAR systems are the main source to acquire reliable remote sensing data. With the current available SAR satellites, the data typically has a ground resolution in the range of a few meters, e.g. 3 m StripMap data from TerraSAR-X used for the Elevation10 DEM product. With the availability of the new sub-meter Staring SpotLight mode for the TerraSAR-X and TanDEM-X satellites, a new dimension of resolution is available as input for radargrammetric processing. This paper will discuss the results of radargrammetric processing using sub-meter SAR images from TerraSAR-X Staring...
The first German space mission TerraSAR-X was launched on June 15th, 2007. Within the TerraSAR-X ... more The first German space mission TerraSAR-X was launched on June 15th, 2007. Within the TerraSAR-X science program of the German Aerospace Center (DLR), the Institute of Digital Image Processing of Joanneum Research (JRDIB) has gained a principal investigator status with respect to the assessment of the mapping potential of TerraSAR-X data using radargrammetric as well as interferometric techniques. As for topographic mapping, TerraSAR has initiated a new generation of high-resolution spaceborne SAR sensors, as it provides SAR images at very high resolution down to 1 meter, based on variable off-nadir looking angles. Thus, high resolution SAR stereo image pairs can be acquired in different imaging dispositions, stimulating the traditional stereo mapping approach to be used for 3D mapping, either in parallel with or as an alternative to SAR interferometry as the evolving mapping technique of the last decade. In order to assess the potential of TerraSAR-X for 2D and 3D mapping applicati...
The TerraSAR-X mission was launched in June 2007 operating a very high resolution X-band SAR sens... more The TerraSAR-X mission was launched in June 2007 operating a very high resolution X-band SAR sensor. In Spotlight mode images are collected with 0.75m GSD and also at various look angles. The presented paper reports methodologies, algorithms and results emerged from the Austrian research project “Advanced Tools for TerraSAR-X Applications in GMES” with emphasis on retrieval of forest parameters. For deriving forest features like crown closure, vertical stand structure or stand height a digital forest canopy model serves as an important source of information. The procedures to be applied cover advanced stereo-radargrammetric and interferometric data processing, as well as image segmentation and image classification. A core development is the multi-image matching concept for digital surface modelling based on geometrically constrained matching, extending the standard stereo-radargrammetric approach. Validation of surface models generated in this way is made through comparison with LiD...
Based on a first prototype, an improved low-cost aerial platform was developed at the Institute o... more Based on a first prototype, an improved low-cost aerial platform was developed at the Institute of Digital Image Processing in order to be used for immediate acquisition and processing of image data wherever necessary. Typically, such requirements arise in case of natural hazards, where the amount of environmental or infrastructural damage has to be rapidly assessed and quantified. In general, the platform comprises a camera as well as GPS and IMU instruments in order to record the position and orientation of the camera. Using a helicopter, first campaigns have been flown with this platform over various urban and sub-urban test sites in Vienna and Graz in order to map buildings, or – more generally to create digital surface models. Ground control points were measured and used for these test sites to perform aero-triangulation via block adjustment, and to estimate and validate the potential accuracy with respect to 3D mapping. In this paper, pilot mapping applications are presented, ...
The presented study focuses on the derivation and validation of digital surface models and digita... more The presented study focuses on the derivation and validation of digital surface models and digital forest canopy height models using multi-beam TerraSAR-X Spotlight data. The derivation of these elevation models is based on multi-image radargrammetry and the validation is based on a comparison to laser scanner DSM and DTM. It is shown that the resulting DSMs are very accurate (+/- 1 meter) on bare ground, while forest canopy heights are systematically underestimated. This bias is caused as the SAR signal in X-band penetrates into the forest canopy, where the penetration depth depends on the off-nadir look angle.
High resolution space-borne remote sensing image data show a high level of detail and provide man... more High resolution space-borne remote sensing image data show a high level of detail and provide manifold opportunities to be integrated into remote sensing applications. In particular, surface mapping from stereo data sets becomes feasible with a height accuracy in the meter range. Following the focus on forest applications of the Institute, the feasibility to determine tree heights from high resolution space-borne Ikonos stereo data but also from airborne stereo image data acquired by the digital UltraCam camera was investigated. A comparative quality assessment of the achieved results was made with respect to those achieved from laser scanning and with respect to in-situ field measurements.
2017 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images (MultiTemp)
American Journal of Remote Sensing
The Pléiades satellite constellation provides very high resolution multi-spectral optical data at... more The Pléiades satellite constellation provides very high resolution multi-spectral optical data at a ground sampling distance of about 0.7 m at nadir direction. Due to the highly agile pointing angle capacity in the range of ±47 degrees the sensors are optimal for detailed earth observation. They are able to collect stereo and tri-stereo datasets in one overflight with a swath width of 20 km. Such images allow 3D mapping of any region on the Earth's surface at very high resolution with high accuracy, where the reconstruction of the heights is based on along-track stereo. This work presents methodologies and workflows within the fields of remote sensing and computer vision that are used (1) to densely reconstruct digital surface models (DSM), (2) to derive digital terrain models (DTM), and (3) to generate multi-spectral ortho-rectified products. Within this process, the accuracy of the geometric sensor models, given as rational polynomial coefficient (RPC) models, plays a crucial role. Therefore, an assessment is performed on two distinct test sites discussing the initial 2D geo-location accuracy of the given sensor models. An optimization scheme is presented to adjust the given RPC models yielding 3D geo-location accuracies of 0.5 m in planimetry and 1 m in height. In the frame of surface model generation important issues like epipolar rectification, hierarchical stereo matching, and fusion of heights are reported. The main outcomes are that the sensor accuracy is within the range as defined by Astrium, but that a sensor model optimization is obligatory when it comes to highly accurate 3D mapping. The presented workflow generates mapping products with a GSD of 0.5m. The derived DSMs and DTMs show a high level of detail, thus enabling varying applications on a large scale, like land cover and land use classification, change detection, city modelling, or forest assessment.
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences
The Pléiades satellites provide very high resolution optical data at a swath width of 20 km and a... more The Pléiades satellites provide very high resolution optical data at a swath width of 20 km and a ground sampling distance of about 0.7 m at nadir direction. The sensors are remarkable agile as their pointing angle can be changed in a range of ±47 degrees. Thus, they are able to collect three images in one over flight representing tri-stereo data. In the presented work the mapping potential of Pléiades stereo and tri-stereo data is assessed in detail. The assessment is performed on two test sites and contains discussions on 2D initial geo-location accuracy, sensor model optimization, 3D geo-location accuracy, and a novel workflow for dense reconstruction of digital surface models (DSMs). The main outcomes are that the sensor accuracy is within the range as defined by Astrium, however a sensor model optimization is obligatory when it comes to highly accurate 3D mapping. The derived DSMs show a high level of detail thus enabling varying applications on a large scale, like chang...
Abstract : Radargrammetric techniques, developed to support stereo mensuration and data capture f... more Abstract : Radargrammetric techniques, developed to support stereo mensuration and data capture from synthetic aperture radar (SAR) imagery, have been extended to enable map-to-image correspondence for computer-assisted radar image analysis. This mechanism projects existing digital map data into the image space of a new SAR image rigorously accounting for the sensor imaging geometry and terrain configuration. Prerequisites for SAR map-to-image correspondence include (1) an analytical sensor model, (2) recovery of the image acquisition parameters and (3) three-dimensional (3d) digital map data. Analytical radar mapping techniques address the first two issues. Suitable 3d planimetric map data can be compiled directly from stereo photography using analytical plotters or indirectly using elevation data interpolated from digital elevation models to augment conventional two-dimensional map data derived from manuscripts. The approach is illustrated by selected examples from a case study conducted for a test area near Frieburg, West Germany. Here, 3d digital data for transportation and landcover maps were assembled from cartographic sources using planimetric augmentation.
2015 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 2015
Radargrammetry is a well-established technique for deriving digital surface models (DSMs) from sy... more Radargrammetry is a well-established technique for deriving digital surface models (DSMs) from synthetic aperture radar images. This work focuses on the novel Staring Spotlight mode of the TerraSAR-X satellite which delivers images with a GSD down to 16 cm. Employing such images, the 2D and 3D geo-location accuracy of the physical sensor models - integrated into SAR range/Doppler equations - is assessed and an automated workflow for DSM extraction is presented. An analysis of the mapping potential completes this study by evaluating the DSM accuracies w.r.t. reference LiDAR data.
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003
Coregistration and geocoding are standard methods to generate registered stacks of multiple remot... more Coregistration and geocoding are standard methods to generate registered stacks of multiple remote sensing image data. It is shown that pixel-based image matching is a useful tool to automate these procedures. Demonstration examples are provided for a multi-temporal set of ERS SAR images.
On the Spot 5 satellite stereo data can be acquired simultaneously from the HRS (high resolution ... more On the Spot 5 satellite stereo data can be acquired simultaneously from the HRS (high resolution stereoscopic) instrument, which comprises 2 cameras looking forward and backward, respectively, at an off-nadir angle of ± 20 degrees. Enhanced along-track pixel resolution of 5 meters shall further assure a high accuracy with respect to 3D data extraction. In this concern, an HRS study team was installed and specific test sites designated in order to validate the geometric performance of Spot 5 HRS stereo data. This paper summarizes the results which have been achieved from the validation activities of the Institute of Digital Image Processing. The investigations were carried out using a test data set acquired over the city of Barcelona. Study areas showing different topographic characteristics have been investigated. Beside pure HRS stereo data, a glimpse has been further made onto the joint use of the HRS stereo data and a supermode THR image, which is basically a nadir scene with a pixel size of 2.5 meters.
The providing of basic data for decision procedures in disaster management is carried out to an e... more The providing of basic data for decision procedures in disaster management is carried out to an ever increasing extent by means of remote sensing methods. Here, not only the accuracy and availability of data, but also an easy and affordable evaluation represents an important factor. That is why the automation of all sorts of processes in data preparation and analysis gains increasingly more importance. Within the framework of this contribution it will be described how basic data are acquired and visualized automatedly by means of remote sensing methods for areas, where existing maps and geodata are available only to a small extent. Here, a continuous production line starting from the creation of an elevation model, geo-referencing and classification up to the automated 3D-visualization of test areas in the Mediterranean area is described. The data processing ranges from the calculation of surface models, digital elevation models (DEMs) and geocoding of high resolution satellite images to classification of vegetation and biomass calculation. Based on these DEMs as well as on optimized parametric sensor models, multispectral as well as panchromatic Quickbird images are geocoded. The classification of vegetation makes use of "pan-sharpened" Quickbird images resulting from data fusion of panchromatic and multispectral images. Biomass data can be calculated from the classification results and forest heights, which are extracted from surface models in order to support fire prevention carried out by local forest managements. For the presentation of these results 3D landscape visualization plays a crucial role because classification results which may be raster or vector maps using specific colours for different classes are not easy to understand for all users involved into fire prevention. The construction of photo-realistic 3D views and 3D animations based on artificial textures and on artificial ecosystems allows us to realise an easily understandable presentation of the current vegetation situation and possible changes in the future. Thus the automatic 3D visualization of raster and vector data will be the main aspect of this paper. Based on the landscape model constructed from the above described DEMs and classification results, a strategy will be described making possible the automatic 3D visualization of every vegetation analysis and change simulation without additional effort. Thus the fire fighting services will get an additional innovative tool for planning and decision making.
The German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) is an element in... more The German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) is an element in the network of the Multimission Facilities of ESA and responsible among other tasks for SAR processing. The DLR has implemented a service for value added products over land. This service can support the user community with preceise geocoded products in addtion to the standard products of ESA. The Envisat GEOcoding system (EGEO) support the highresolution image modes, the medium resolution and the global mode from ENVISAT, product examples will be presented. The user service includes also the integration of national geodetic maping parameter to the products. Different datumshift parameter sets are implemeted. New parameter sets can be easily integrated, if the user can deliver the required geodetic parameters. Two major types of geocoded products are available: · Enhanced Ellipsoid Corretced (EEC) · Enhanced Geocoded Terrain Corrected (ETC) The EEC generation is a fully automated process...
As for any other remote sensing data, the geometric fidelity of Envisat ASAR image products is of... more As for any other remote sensing data, the geometric fidelity of Envisat ASAR image products is of interest to the user community. The Institute of Digital Image Processing is in charge to check and proof the geometric quality of Envisat products acquired in the ASAR image mode. This paper focusses on results, which have been achieved for a data set comprising IMP and IMM products, which represent the precision and the medium resolution mode, respectively, and which have been acquired over the Flevopolder test site. With regard to geometic validation, the a-priori location accuracy of the Envisat products is of particular relevance. As demonstrated through the validation tests, the ASAR products being investigated in general show a highly acceptable geometric performance and promise to be valuable fundamentals for geo-scientific applications. 1
Based on a first prototype, an improved low-cost aerial platform was developed at the Institute o... more Based on a first prototype, an improved low-cost aerial platform was developed at the Institute of Digital Image Processing in order to be used for immediate acquisition and processing of image data wherever necessary. Typically, such requirements arise in case of natural hazards, where the amount of environmental or infrastructural damage has to be rapidly assessed and quantified. In general, the platform comprises a camera as well as GPS and IMU instruments in order to record the position and orientation of the camera. Using a helicopter, first campaigns have been flown with this platform over various urban and sub-urban test sites in Vienna and Graz in order to map buildings, or – more generally- to create digital surface models. Ground control points were measured and used for these test sites to perform aero-triangulation via block adjustment, and to estimate and validate the potential accuracy with respect to 3D mapping. In this paper, pilot mapping applications are presented,...
For several years the technique of radargrammetry with high resolution Synthetic Aperture Radar (... more For several years the technique of radargrammetry with high resolution Synthetic Aperture Radar (SAR) data has been used in scientific and commercial environment for Digital Elevation Modelling (DEM). Compared to repeat pass interferometry, radargrammetry is a robust DEM generation technique for almost all areas on the globe due to phase independent matching algorithms. Particularly in areas with high cloud coverage, SAR systems are the main source to acquire reliable remote sensing data. With the current available SAR satellites, the data typically has a ground resolution in the range of a few meters, e.g. 3 m StripMap data from TerraSAR-X used for the Elevation10 DEM product. With the availability of the new sub-meter Staring SpotLight mode for the TerraSAR-X and TanDEM-X satellites, a new dimension of resolution is available as input for radargrammetric processing. This paper will discuss the results of radargrammetric processing using sub-meter SAR images from TerraSAR-X Staring...
The first German space mission TerraSAR-X was launched on June 15th, 2007. Within the TerraSAR-X ... more The first German space mission TerraSAR-X was launched on June 15th, 2007. Within the TerraSAR-X science program of the German Aerospace Center (DLR), the Institute of Digital Image Processing of Joanneum Research (JRDIB) has gained a principal investigator status with respect to the assessment of the mapping potential of TerraSAR-X data using radargrammetric as well as interferometric techniques. As for topographic mapping, TerraSAR has initiated a new generation of high-resolution spaceborne SAR sensors, as it provides SAR images at very high resolution down to 1 meter, based on variable off-nadir looking angles. Thus, high resolution SAR stereo image pairs can be acquired in different imaging dispositions, stimulating the traditional stereo mapping approach to be used for 3D mapping, either in parallel with or as an alternative to SAR interferometry as the evolving mapping technique of the last decade. In order to assess the potential of TerraSAR-X for 2D and 3D mapping applicati...
The TerraSAR-X mission was launched in June 2007 operating a very high resolution X-band SAR sens... more The TerraSAR-X mission was launched in June 2007 operating a very high resolution X-band SAR sensor. In Spotlight mode images are collected with 0.75m GSD and also at various look angles. The presented paper reports methodologies, algorithms and results emerged from the Austrian research project “Advanced Tools for TerraSAR-X Applications in GMES” with emphasis on retrieval of forest parameters. For deriving forest features like crown closure, vertical stand structure or stand height a digital forest canopy model serves as an important source of information. The procedures to be applied cover advanced stereo-radargrammetric and interferometric data processing, as well as image segmentation and image classification. A core development is the multi-image matching concept for digital surface modelling based on geometrically constrained matching, extending the standard stereo-radargrammetric approach. Validation of surface models generated in this way is made through comparison with LiD...
Based on a first prototype, an improved low-cost aerial platform was developed at the Institute o... more Based on a first prototype, an improved low-cost aerial platform was developed at the Institute of Digital Image Processing in order to be used for immediate acquisition and processing of image data wherever necessary. Typically, such requirements arise in case of natural hazards, where the amount of environmental or infrastructural damage has to be rapidly assessed and quantified. In general, the platform comprises a camera as well as GPS and IMU instruments in order to record the position and orientation of the camera. Using a helicopter, first campaigns have been flown with this platform over various urban and sub-urban test sites in Vienna and Graz in order to map buildings, or – more generally to create digital surface models. Ground control points were measured and used for these test sites to perform aero-triangulation via block adjustment, and to estimate and validate the potential accuracy with respect to 3D mapping. In this paper, pilot mapping applications are presented, ...
The presented study focuses on the derivation and validation of digital surface models and digita... more The presented study focuses on the derivation and validation of digital surface models and digital forest canopy height models using multi-beam TerraSAR-X Spotlight data. The derivation of these elevation models is based on multi-image radargrammetry and the validation is based on a comparison to laser scanner DSM and DTM. It is shown that the resulting DSMs are very accurate (+/- 1 meter) on bare ground, while forest canopy heights are systematically underestimated. This bias is caused as the SAR signal in X-band penetrates into the forest canopy, where the penetration depth depends on the off-nadir look angle.
High resolution space-borne remote sensing image data show a high level of detail and provide man... more High resolution space-borne remote sensing image data show a high level of detail and provide manifold opportunities to be integrated into remote sensing applications. In particular, surface mapping from stereo data sets becomes feasible with a height accuracy in the meter range. Following the focus on forest applications of the Institute, the feasibility to determine tree heights from high resolution space-borne Ikonos stereo data but also from airborne stereo image data acquired by the digital UltraCam camera was investigated. A comparative quality assessment of the achieved results was made with respect to those achieved from laser scanning and with respect to in-situ field measurements.
2017 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images (MultiTemp)
American Journal of Remote Sensing
The Pléiades satellite constellation provides very high resolution multi-spectral optical data at... more The Pléiades satellite constellation provides very high resolution multi-spectral optical data at a ground sampling distance of about 0.7 m at nadir direction. Due to the highly agile pointing angle capacity in the range of ±47 degrees the sensors are optimal for detailed earth observation. They are able to collect stereo and tri-stereo datasets in one overflight with a swath width of 20 km. Such images allow 3D mapping of any region on the Earth's surface at very high resolution with high accuracy, where the reconstruction of the heights is based on along-track stereo. This work presents methodologies and workflows within the fields of remote sensing and computer vision that are used (1) to densely reconstruct digital surface models (DSM), (2) to derive digital terrain models (DTM), and (3) to generate multi-spectral ortho-rectified products. Within this process, the accuracy of the geometric sensor models, given as rational polynomial coefficient (RPC) models, plays a crucial role. Therefore, an assessment is performed on two distinct test sites discussing the initial 2D geo-location accuracy of the given sensor models. An optimization scheme is presented to adjust the given RPC models yielding 3D geo-location accuracies of 0.5 m in planimetry and 1 m in height. In the frame of surface model generation important issues like epipolar rectification, hierarchical stereo matching, and fusion of heights are reported. The main outcomes are that the sensor accuracy is within the range as defined by Astrium, but that a sensor model optimization is obligatory when it comes to highly accurate 3D mapping. The presented workflow generates mapping products with a GSD of 0.5m. The derived DSMs and DTMs show a high level of detail, thus enabling varying applications on a large scale, like land cover and land use classification, change detection, city modelling, or forest assessment.
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences
The Pléiades satellites provide very high resolution optical data at a swath width of 20 km and a... more The Pléiades satellites provide very high resolution optical data at a swath width of 20 km and a ground sampling distance of about 0.7 m at nadir direction. The sensors are remarkable agile as their pointing angle can be changed in a range of ±47 degrees. Thus, they are able to collect three images in one over flight representing tri-stereo data. In the presented work the mapping potential of Pléiades stereo and tri-stereo data is assessed in detail. The assessment is performed on two test sites and contains discussions on 2D initial geo-location accuracy, sensor model optimization, 3D geo-location accuracy, and a novel workflow for dense reconstruction of digital surface models (DSMs). The main outcomes are that the sensor accuracy is within the range as defined by Astrium, however a sensor model optimization is obligatory when it comes to highly accurate 3D mapping. The derived DSMs show a high level of detail thus enabling varying applications on a large scale, like chang...
Abstract : Radargrammetric techniques, developed to support stereo mensuration and data capture f... more Abstract : Radargrammetric techniques, developed to support stereo mensuration and data capture from synthetic aperture radar (SAR) imagery, have been extended to enable map-to-image correspondence for computer-assisted radar image analysis. This mechanism projects existing digital map data into the image space of a new SAR image rigorously accounting for the sensor imaging geometry and terrain configuration. Prerequisites for SAR map-to-image correspondence include (1) an analytical sensor model, (2) recovery of the image acquisition parameters and (3) three-dimensional (3d) digital map data. Analytical radar mapping techniques address the first two issues. Suitable 3d planimetric map data can be compiled directly from stereo photography using analytical plotters or indirectly using elevation data interpolated from digital elevation models to augment conventional two-dimensional map data derived from manuscripts. The approach is illustrated by selected examples from a case study conducted for a test area near Frieburg, West Germany. Here, 3d digital data for transportation and landcover maps were assembled from cartographic sources using planimetric augmentation.
2015 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 2015
Radargrammetry is a well-established technique for deriving digital surface models (DSMs) from sy... more Radargrammetry is a well-established technique for deriving digital surface models (DSMs) from synthetic aperture radar images. This work focuses on the novel Staring Spotlight mode of the TerraSAR-X satellite which delivers images with a GSD down to 16 cm. Employing such images, the 2D and 3D geo-location accuracy of the physical sensor models - integrated into SAR range/Doppler equations - is assessed and an automated workflow for DSM extraction is presented. An analysis of the mapping potential completes this study by evaluating the DSM accuracies w.r.t. reference LiDAR data.
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003
Coregistration and geocoding are standard methods to generate registered stacks of multiple remot... more Coregistration and geocoding are standard methods to generate registered stacks of multiple remote sensing image data. It is shown that pixel-based image matching is a useful tool to automate these procedures. Demonstration examples are provided for a multi-temporal set of ERS SAR images.
On the Spot 5 satellite stereo data can be acquired simultaneously from the HRS (high resolution ... more On the Spot 5 satellite stereo data can be acquired simultaneously from the HRS (high resolution stereoscopic) instrument, which comprises 2 cameras looking forward and backward, respectively, at an off-nadir angle of ± 20 degrees. Enhanced along-track pixel resolution of 5 meters shall further assure a high accuracy with respect to 3D data extraction. In this concern, an HRS study team was installed and specific test sites designated in order to validate the geometric performance of Spot 5 HRS stereo data. This paper summarizes the results which have been achieved from the validation activities of the Institute of Digital Image Processing. The investigations were carried out using a test data set acquired over the city of Barcelona. Study areas showing different topographic characteristics have been investigated. Beside pure HRS stereo data, a glimpse has been further made onto the joint use of the HRS stereo data and a supermode THR image, which is basically a nadir scene with a pixel size of 2.5 meters.
The providing of basic data for decision procedures in disaster management is carried out to an e... more The providing of basic data for decision procedures in disaster management is carried out to an ever increasing extent by means of remote sensing methods. Here, not only the accuracy and availability of data, but also an easy and affordable evaluation represents an important factor. That is why the automation of all sorts of processes in data preparation and analysis gains increasingly more importance. Within the framework of this contribution it will be described how basic data are acquired and visualized automatedly by means of remote sensing methods for areas, where existing maps and geodata are available only to a small extent. Here, a continuous production line starting from the creation of an elevation model, geo-referencing and classification up to the automated 3D-visualization of test areas in the Mediterranean area is described. The data processing ranges from the calculation of surface models, digital elevation models (DEMs) and geocoding of high resolution satellite images to classification of vegetation and biomass calculation. Based on these DEMs as well as on optimized parametric sensor models, multispectral as well as panchromatic Quickbird images are geocoded. The classification of vegetation makes use of "pan-sharpened" Quickbird images resulting from data fusion of panchromatic and multispectral images. Biomass data can be calculated from the classification results and forest heights, which are extracted from surface models in order to support fire prevention carried out by local forest managements. For the presentation of these results 3D landscape visualization plays a crucial role because classification results which may be raster or vector maps using specific colours for different classes are not easy to understand for all users involved into fire prevention. The construction of photo-realistic 3D views and 3D animations based on artificial textures and on artificial ecosystems allows us to realise an easily understandable presentation of the current vegetation situation and possible changes in the future. Thus the automatic 3D visualization of raster and vector data will be the main aspect of this paper. Based on the landscape model constructed from the above described DEMs and classification results, a strategy will be described making possible the automatic 3D visualization of every vegetation analysis and change simulation without additional effort. Thus the fire fighting services will get an additional innovative tool for planning and decision making.
The German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) is an element in... more The German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) is an element in the network of the Multimission Facilities of ESA and responsible among other tasks for SAR processing. The DLR has implemented a service for value added products over land. This service can support the user community with preceise geocoded products in addtion to the standard products of ESA. The Envisat GEOcoding system (EGEO) support the highresolution image modes, the medium resolution and the global mode from ENVISAT, product examples will be presented. The user service includes also the integration of national geodetic maping parameter to the products. Different datumshift parameter sets are implemeted. New parameter sets can be easily integrated, if the user can deliver the required geodetic parameters. Two major types of geocoded products are available: · Enhanced Ellipsoid Corretced (EEC) · Enhanced Geocoded Terrain Corrected (ETC) The EEC generation is a fully automated process...