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Theme issue on “Mapping with SAR: Techniques and applications”
ISPRS Journal of Photogrammetry and Remote Sensing 64 (2009) 433
Contents lists available at ScienceDirect
ISPRS Journal of Photogrammetry and Remote Sensing journal homepage: www.elsevier.com/locate/isprsjprs
Editorial
Theme issue on ‘‘Mapping with SAR: Techniques and applications’’ This theme issue is dedicated to the topic ‘‘Mapping with SAR: Techniques and Applications". The objective of this theme issue is to give an overview on recent advances in the field of mapping with synthetic aperture radar (SAR), bringing together participants from the research, industrial, and academic communities who are engaged in mapping projects involving the technologies and techniques of SAR. In fact, during the last two decades SAR became an indispensable source of information in Earth observation since SAR is the only space-borne sensor that has high-resolution all-weather day-and-night imaging capability. In many cases, information extraction from SAR imagery has achieved a mature level, turning SAR technology more and more into an operational tool. In particular this holds for regular monitoring and mapping applications, where high reliability of the remotely sensed data is essential. Today, we are on the edge of a new era of operational SAR systems. Recent years have shown a rapid development of advanced SAR technology; new sensors embody several novel features, such as higher resolution, partial and full polarimetry and new innovative imaging modes. Within the next ten years, more than 20 spaceborne SAR systems from different nations will be launched, bringing these novel SAR concepts into regular operation. New satellite systems like, for example, TanDEM-X, KompSAT-5, Radarsat-3 and TerraSAR-X2 will provide SAR images of unmatched quality, coverage and resolution. They will also significantly outperform existing systems with respect to their flexibility, available imaging modes and number of receiving channels. For this ISPRS theme issue, we obtained a good response to the call for papers: from twenty four original submissions, eight papers have been selected for publication and grouped according to their field of application: land and crop mapping or urban area monitoring. This theme issue on mapping with SAR starts with the paper by McNairn et al. which demonstrates how optical and time series of SAR images can be integrated to deliver annual crop inventories in an operational way. This study shows that combining multitemporal optical and dual-polarization SAR images allows high identification rates and reduces the risk of cloud and haze induced artifacts over an optical-only approach. The second paper, written by Waske and Braun, proposes to use classifier ensembles for land cover mapping using single- and dual polarization multitemporal SAR data and shows that this classification approach has some significant advantages over classical methods. The papers by
Silva et al. and by Ainsworth et al. demonstrate the importance of polarization diversity for land and crop classification. Both articles show that fully polarimetric data provide significant identification improvements compared to single-polarization measurements and study various partially polarimetric configurations and their impact on classification performance. The last paper dealing with land and crop mapping concerns the characterization of ravines using interferometric SAR data sets. Chatterjee et al. show that small-scale variations of the interferometric information can be related to the density, depth and surface cover of ravines and then mapped. The second part of this theme issue concerns urban area monitoring and starts with the paper by Dell’Acqua et al. which proposes to map man-made features, like built-up areas, road networks using high resolution SAR images and multi-scale image processing techniques, such as texture analysis and feature recognition. In their paper, Soergel et al. show how very high resolution stereo SAR images, acquired from orthogonal flight tracks, can be processed to estimate building heights in an accurate way. The final paper of this theme issue concerns the mapping of urban area deformation and its evolution with time using differential interferometry techniques. Herrera et al. compare different processing techniques which successfully estimate deformation velocities of some mm/year. We would like to thank all the reviewers for their time and dedication to the review process. The Guest Editors are also very grateful to Prof. George Vosselman, Editor-in-Chief of the ISPRS Journal of Photogrammetry and Remote Sensing, for his encouragement and support in preparing this theme issue.
Andreas Reigber ∗ Microwaves and Radar Institute, German Aerospace Center (DLR), D-82230 Oberpfaffenhofen, Germany E-mail address: [email protected]. Laurent Ferro-Famil Institut d’Electronique et des Télécommunications de Rennes, University of Rennes 1, F-35042 Rennes, France E-mail address: [email protected]. Available online 23 May 2009 ∗ Corresponding editor.
0924-2716/$ – see front matter © 2009 Published by Elsevier B.V. on behalf of International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). doi:10.1016/j.isprsjprs.2009.05.001
Contents lists available at ScienceDirect
ISPRS Journal of Photogrammetry and Remote Sensing journal homepage: www.elsevier.com/locate/isprsjprs
Editorial
Theme issue on ‘‘Mapping with SAR: Techniques and applications’’ This theme issue is dedicated to the topic ‘‘Mapping with SAR: Techniques and Applications". The objective of this theme issue is to give an overview on recent advances in the field of mapping with synthetic aperture radar (SAR), bringing together participants from the research, industrial, and academic communities who are engaged in mapping projects involving the technologies and techniques of SAR. In fact, during the last two decades SAR became an indispensable source of information in Earth observation since SAR is the only space-borne sensor that has high-resolution all-weather day-and-night imaging capability. In many cases, information extraction from SAR imagery has achieved a mature level, turning SAR technology more and more into an operational tool. In particular this holds for regular monitoring and mapping applications, where high reliability of the remotely sensed data is essential. Today, we are on the edge of a new era of operational SAR systems. Recent years have shown a rapid development of advanced SAR technology; new sensors embody several novel features, such as higher resolution, partial and full polarimetry and new innovative imaging modes. Within the next ten years, more than 20 spaceborne SAR systems from different nations will be launched, bringing these novel SAR concepts into regular operation. New satellite systems like, for example, TanDEM-X, KompSAT-5, Radarsat-3 and TerraSAR-X2 will provide SAR images of unmatched quality, coverage and resolution. They will also significantly outperform existing systems with respect to their flexibility, available imaging modes and number of receiving channels. For this ISPRS theme issue, we obtained a good response to the call for papers: from twenty four original submissions, eight papers have been selected for publication and grouped according to their field of application: land and crop mapping or urban area monitoring. This theme issue on mapping with SAR starts with the paper by McNairn et al. which demonstrates how optical and time series of SAR images can be integrated to deliver annual crop inventories in an operational way. This study shows that combining multitemporal optical and dual-polarization SAR images allows high identification rates and reduces the risk of cloud and haze induced artifacts over an optical-only approach. The second paper, written by Waske and Braun, proposes to use classifier ensembles for land cover mapping using single- and dual polarization multitemporal SAR data and shows that this classification approach has some significant advantages over classical methods. The papers by
Silva et al. and by Ainsworth et al. demonstrate the importance of polarization diversity for land and crop classification. Both articles show that fully polarimetric data provide significant identification improvements compared to single-polarization measurements and study various partially polarimetric configurations and their impact on classification performance. The last paper dealing with land and crop mapping concerns the characterization of ravines using interferometric SAR data sets. Chatterjee et al. show that small-scale variations of the interferometric information can be related to the density, depth and surface cover of ravines and then mapped. The second part of this theme issue concerns urban area monitoring and starts with the paper by Dell’Acqua et al. which proposes to map man-made features, like built-up areas, road networks using high resolution SAR images and multi-scale image processing techniques, such as texture analysis and feature recognition. In their paper, Soergel et al. show how very high resolution stereo SAR images, acquired from orthogonal flight tracks, can be processed to estimate building heights in an accurate way. The final paper of this theme issue concerns the mapping of urban area deformation and its evolution with time using differential interferometry techniques. Herrera et al. compare different processing techniques which successfully estimate deformation velocities of some mm/year. We would like to thank all the reviewers for their time and dedication to the review process. The Guest Editors are also very grateful to Prof. George Vosselman, Editor-in-Chief of the ISPRS Journal of Photogrammetry and Remote Sensing, for his encouragement and support in preparing this theme issue.
Andreas Reigber ∗ Microwaves and Radar Institute, German Aerospace Center (DLR), D-82230 Oberpfaffenhofen, Germany E-mail address: [email protected]. Laurent Ferro-Famil Institut d’Electronique et des Télécommunications de Rennes, University of Rennes 1, F-35042 Rennes, France E-mail address: [email protected]. Available online 23 May 2009 ∗ Corresponding editor.
0924-2716/$ – see front matter © 2009 Published by Elsevier B.V. on behalf of International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). doi:10.1016/j.isprsjprs.2009.05.001