ID: 57637
Title: Establishing climate information service system for climate change adaptation in Himalayan region
Author: Manoranjan Mishra, Dinoj Kumar Upadhyay and Shailendra Kumar Mishra
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Climate change, databases, highland areas, information service systems
Abstract: The opportunities available for rural households in the Himalayan region to cope with changing cliamte should involve acting in shorter timescales with development agenda of the region. The present article is an attempt to propose pathways of using available climate information to solve local problems caused by climate change. Existing information systems and databases can be organized to understand the solutions of climate change which can be appropriately implemented in highland areas. The study suggests systematiclly capitalizing the existing indigenous wisdom, current climate variability databases and growing information technology to help highland people cope under the local climatic constraints.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57636
Title: Sandalwood: history, uses, present status and the future
Author: A N Arun Kumar, Geeta Joshi and H Y Mohan Ram
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Heartwood and oil content, phytoplasm, restoration strategies, Santalum album, traditional value
Abstract: Sandalwood (Santalum album L) is a valuable tree asssociated with Indian culture. It is the second most expensive wood in the world. The heartwood of the tree is treasured for its aroma and is one of the finest natural materials for carving. Sandalwood oil is used in perfumes, cosmetics, aromatherapy and pharmaceuticals. The monopoly of sandalwood trade by the Governments of Karnataka, Tamil Nadu and Kerala and its consequences have resulted in severe exploitation, pushing S. album into the vulnerable category of the IUCN Red List. Extensive research has shown that sandalwood exhibits considerable genetic diversity for different traits. However, information pertaining to heartwood adn oil content is meagre mainly because of non-availability of sandalwood plantations. Carrying out further research on these two important traits is difficult as natural populations have dwindled rapidly. We strongly urge that it is essential to encourage the establishment of community/corporate sandalwood plantations in different parts of India with appropriate incentives and adequate protective measures. These plantations can form the base population sources to regain the leadership of India in the sandalwood industry for perfumery and the precious art of carving.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57635
Title: Synchronous reduction in Indian summer and winter monsoon intensity during the northern hemisphere cold episodes: possible implications on climate modelling
Author: M S Srinivasan
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57634
Title: Is Berberis asiatica a good substitute for Berberis aristata in preparation of hepatoprotective drugs?
Author: Harish C Andola, Vijay K Purohit
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57633
Title: Recent cloudburst-induced landslides around Okhimath, Uttarakhand
Author: Naresh Rana, Y P Sundriyal, N Juyal
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57632
Title: Oran of Rohida: an endangered tree species of Rajasthan
Author: Desha Meena, Anil Singh
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, VOl 103, No 12, 25 December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57631
Title: Remote Sensing Digital Image Analysis - An introduction Fourth Edition
Author: None
Editor: John A Richards, Xiuping Jia
Year: 2008
Publisher: Springer (India) Private Limited
Source: Centre for Ecological Sciences
Reference: None
Subject: Remote Sensing
Keywords: None
Abstract: None
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57630
Title: An advanced algorithm for deformation estimation in non-urban areas
Author: Kanika Goel, Nico Adam
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Adaptive spatial phase filtering, Distributed scatterer (DS), L1 norm minimization, Small Baseline Subset Algorithm (SBAS), TerraSAR-X
Abstract: This paper presents an advanced differential SAR interferometry stacking algorithm for high resolution deformation monitoring in non-urban areas with a focus on distributed scatterers (DSs). Techniques such as the Small Baseline Subset Algorithm (SBAS) have been proposed for processing DSs. SBAS makes use of small baseline differential interferogram subsets. Singular value decomposition (SVD), i.e. L2 norm minimization is applied to link independent subsets separated by large baselines. However, the interferograms used in SBAS are multilooked using a rectangular window to reduce phase noise caused for instance by temporal decorrelation, resulting in a loss of resolution and the superposition of topography and deformation signals from different objects. Moreover, these have to be individually phase unwrapped and this can be especially difficult in natural terrains. An improved deformation estimation technique is presented here which exploits high resolution SAR data and is suitable for rural areas. The implemented method makes use of small baseline differential interferograms and incorporates an object adaptive spatial phase filtering and residual topography removal for an accurate phase and coherence estimation, while preserving the high resolution provided by modern satellites. This is followed by retrieval of deformation via the SBAS approach, wherein, the phase inversion is performed using an L1 norm minimization which is more robust to the typical phase unwrapping errors encountered in non-urban area. Meter resolution TerraSAR-X datra of an underground storage reservoir in Germany is used for demonstrating the effectiveness of this newly developed technique in rural areas.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57629
Title: Retrieval of phase history parameters from distributed scatterers in urban areas using very high resolution SAR data
Author: Yuanyuan Wang, Xiao Xiang Zhu, Richar Bamler
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Phase history, distributed scatterer, covariance matrix, SAR, PSI, TerraSAR-X
Abstract: In a recent contribution Ferretti and co-workers (Ferretti, A., Fumagalli, A., Novali, F., Prati, C, Rocca, F., Rucci, A., 2011. A new algorithm for processing interfermetric data-stacks: SqueeSAR IEEE Transactions on Geoscience and Remote Sensing 49(9), pp. 3460-3470) have proposed the SqueeSAR method, a way to exploit temporally coherent distributed scatterers in coherent SAR data stacks. Elevation and deformation or subsidence estimates are obtained with accuracy similar as in the well known persistent scatterer interferometry (PSI).
In this paper we propose an alternative approach and provide a first demonstration of the optimal estimation of distributed scatterers ' pahse histories in urban areas. Different to SqueeSAR, we derive phase histories for each distributed scatterer pixel rather than for groups of pixels. We kuse the Anderson-Darling statistical test to identify neighboring samples of the same distribution. Prior to covariance matrix estimation required for maximum likelihood estimation we apply a multi-resolution defringe technique. By using TerraSAR-X high resolution spotlight data, it is demonstrated that we are able to retrieve reliable phase histories and motion parameter estimates from distributed scatterers with signal-to-noise-ratio far below the common range.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57628
Title: Grouping of persistent scatterers in high-resolution SAR data of urban scenes
Author: Alexander Schunert, Uwe Soergel
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: SAR, persistent Scatterer Interferometry, Urban, Grouping, TerraSAR-X
Abstract: Persistent Scatterer Interferometry (PSI) is a technique to simultaneously estimate surface deformation and 3D structure from stacks of SAR images. It was proposed first about one decade ago to monitor preferably urban areas, where in general the highest numbers of PS are found. At that time no high-resolution satellite SAR data were available. Instead, for example, stacks of ERS imagery were used providing ground range resolution of about 25 m. In data of such kind only the strongest PS can be detected, which are usually caused by corner reflectors built by orthogonal building and road planes of considerable size wereas smaller structures causing weaker ones signal are averaged by clutter or mutually interfere with others in the same resolution cell. Thus, if any, only a few or even just one single PS are found per building. The advent of a new senor generation of systems like TerraSAR-X and COSMO-Skymed in 2007 led to a significant improvement of spatial resolution of about one order of magnitude. This comes along with a dramatic rise of PS density: In some cases tens to hundreds are detected at large buildings, which offers the possibility to monitor even individual urban objects.
In addition, especially at building facades the distribution of those PS is often quite regular. A reason for that is the usually rectilinear arrangement of facde structures inducing the PS like windows or balconies. Those patterns contain a lot of information about the objects under investigation, which is mostly ignored in current in current PSI processing schemes. For example, consider a regular structure of windows on a certain facade of a multi-story building. Assuming the same kind of structure generates one single PS at each window, the phase centers of all scatterers caused by windows of each floor share the same height. This means, we may benefit from such kind of redundancy, for instance, to improve the height estimate by averaging over PS having the same elevation.
In this work, we first discuss the regular appearance of PS at urban facades for an urban test scene in TerraSAR-X spotlight mode data. Then, we show how PS analysis could benefit by exploitation of the redundancy due to repetitive patterns of man-made objects. Finally, we propose a PS grouping scheme based on a production system and discuss first results achieved for the test area.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57627
Title: Deformation monitoring of single buildings using meter-resolution SAR data in PSI
Author: Stefan Gernhardt, Richard Bamler
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Urban, monitoring, SAR, high resolution
Abstract: In this paper the feasibility to monitor the shape and deformation of single buildings from space is investigated. The methodology is based on a fusion of persistent scatterer (PS) point clouds obtained from several stacks of meter-resolution synthetic aperture radar (SAR) data. This kind of high resolution imagery as well as accurate orbit information is available from, e.g TerraSAR-X. The stacks are preocessed individually applying persistent scatterer interferometry (PSI), which provides deformation and height estimates for the PS. However, the geocoded PS point clouds cannot be simply merged in one common coordinate system, like UTM, by reason of residual offsets with respect to their final true positions. These deviations originate from the height uncertainty of the reference point, which has to be chosen during PSI processing of each stack. The presented methodology allows for a fusion of several PS point clouds, i.e., the correct reference point heights can be recovered. The algorithm is based on a point cloud matching procedure that consists of a determination of apporpriate point correspondences and a minimization of the distances between all selected pairs of points in a least-squares sense.
In addition, the reconstruction of the original motion vector from the deformation measurements in line of sight provided by PSI is desirable. The availability of separated motion components in vertical and horizontal directions greatly enhances the insights into deformation events at buildings and ground. To this end, the fused point clouds are used for a decomposition of motion components. By reason of the limited sensitivity of ascending and descending stacks of TerraSAR-X to deformation in north-southern directions the reconstruction of motion vector components is restricted to components in west-eastern and vertical directions. The latter are estimated in a least-squares adjustment including all PS within a spatially limited area. Deformation estimates of stacks from ascending and descending tracks must be included in order to separate motion components. The latter cannot be determined precisely from a combination of solely equal heading tracks, as the line of sight does not differ enough. Finally, deformation maps of the urban area are available that separately show seasonal and linear deformation in horizontal as well as vertical directions. These maps comprise important information on subsidence or uplift as well as structural stress at buildings due to thermal dilation. As a result of the presented methodology (and for the first time) sufficient and precise motion estimates are available for a detailed monitoring of single objects using meter-resolution SAR data in PSI. Several examples are discussed using the results of motion component estimation based on the fusion of four data stacks evaluated by PSI.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57626
Title: Shanghai subway tunnels and highways monitoring through Cosmo-SkyMed persistent scatterers
Author: Daniele Perissin, Zhiying Wang, Hui Lin
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Persistent Scatterers, Urban subsidence monitoring, Subways, Highways, Shanghai
Abstract: Synthetic Aperture Radar Interferometry (InSAR) is an alternative technique to obtain measurements of surface displacement providing better spatial resolution and comparable accuracy at an extremely lower cost per area than conventional surveying methods. InSAR is becoming more and more popular in monitoring urban deformations, however, the technique requires advanced tools and high level competence to be successfully applied. In this paper we report important results obtained by analyzing new high resolution SAR data in the Shanghai urban area. The data used in this work have been acquired by the Italian X-band sensor Cosmo-SkyMed. About 1.2 million of individual and independent targets have been detected in 600 sq km, revealing impressive details of the ground surface deformation. Using the SAR-PROZ InSAR tool and integrating the results with Google Earth, we were able to track subway tunnels recently excavated and several highways. Tunnels are visible due to very localized subsidence of the above surface along their path. On the other hand, highways, standing over the ground, in most cases show higher stability than the surrounding areas. The density of targets is so high to allow studying the profile of the tunnel subsidence, which is very useful to predict building damage. Finally, the identification of targets on high buildings helps checking the stability of high constructions along the subway lines, highlighting possible risky situations.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57625
Title: An analysis of terrain properties and the location of surface scatterers from persistent scatterer interferometry
Author: S N Riddick, D A Schmidt, N I Deligne
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: InSAR, Persistent scatterers, StaMPS, Cascades, Three Sisters, LiDAR, SAR, Geology, Land cover, vegetation, volcanoes
Abstract: Standard interferometry poses a challenge in heavily vegetated areas due to decorrelation of the radar signal. To alleviate this problem, we implement StaMPS, a persistent scatterer (PS) technique, to obtain a more spatially complete signal in the Cascade Range of the Pacific Northwest. In addition to comparing the spatial extent of the signal from standard interferometric systhetic Aperture Radar (InSAR) and StaMPS, we further analyze the selection of scatterers over several terrain types in the Cascades, and systematically vary StaMPS parameters to minimize the selection of false positives and negatives. Utilizing the best parameters, we correlate the location of persistent scatters to geologic units, and vegetation density derived from Light Detection and Ranging (LiDAR) data. Our findings indicate that persistent scatterers most frequently occur on young, rough basaltic to andesitic lava flows and to a lesser extent on older, reworked basaltic andesitic lava flows exposed as boulder fields in the forests. Very few or no scatterers were found over water, permanent snowfields, evergreen forest, or unconsolidated pyroclastics. Over 90% of the scatterers are located in areas with no or very sparse vegetation cover. Based on surface roughness and the percentage of bare earth within the radar footprint, we are abole to predict where PS InSAR is most likely to be successful on natural terrains.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57624
Title: Operational TanDEM-X DEM calibration and first validation results
Author: Astrid Gruber, Birgit Wessel, Martin Huber, Achim Roth
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Block adjustment, DEM, calibration, InSAR, TanDEM-X
Abstract: In June 2010, the German TanDEM-X satellite was launched. Together with its twin satellite TerraSAR-X it flies in a close formation enabling single-pass SAR itnerferometry. The primary goal of the TanDEM-X mission is the derivation of a global digital elevation model (DEM) with unprecedented global accuracies of 10m in absolute and 2m in relative height. A significant calibration effort is required to achieve this high quality world-wide. In spite of an intensive instrument calibration and a highly accurate orbit and baseline determination, some systematic height errors like offsets and tilts in the order of some meters remain in the interferometric DEMs and have to be determined and removed during the TanDEM-X DEM calibration. The objective of this article is the presentation of an approach for the estimation of correction parameters for remaining systematic height errors applicalbe to interferometric height models. The approach is based on a least-square block adjustment using the elevation of ICESat GLA 14 data as ground control points and connecting points of adjacent, overlaping DEMs as tie-points. In the first part its implementation in DLR ' s ground segment is outlined. In the second part the approach is applied and validated for two of the first TanDEM-X DEM test sites. Therefore, independent reference data, in particular high resolution reference DEMs and GPS tracks, are used. The results show that the absolute height errors of the TanDEM-X DEM are small in these cases, mostly in the order of 1-2 m. An additional benefit of the proposed block adjustment method is that it improves the relative accuracy of adjacent DEMs.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57623
Title: Relative height error analysis of TanDEM-X elevation data
Author: Paola Rizzoli, Benjamin Brautigam, Thomas Kraus, Michele Martone, Gerhard Krieger
Editor: George Vosselman
Year: 2012
Publisher: Elsevier, Vol 73, September 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: SAR interferometry, Digital elevation model, relative height error, TanDEM - X
Abstract: The primary objective of the TanDEM-X mission is the generation of a global high resolution digital elevation model (DEM) with single-pass SAR interferometry. Within the mission, the Earth ' s land masses will be mapped at least twice to achieve vertical accuracies in the order to two meters. This paper presents an analysis of the mission performance in terms of the relative height error showing first results obtained from TanDEM-X interferometric data. For critical areas characterized by strong volume decor-relation phenomena or mountainous terrain, different approaches to improve the final height error are investigated as well.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None