ID: 57622
Title: Coherence evaluation of TanDEM - X interferometric data
Author: Michele Martone, Benjamin Brautigam, Paola Rizzoli, Carolina Gonzalez, Markus Bachmann, 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: Synthetic Aperture Radar (SAR), Bistatic SAR, interferometry, Coherence, Digital elevation model (DEM), TanDEM-X
Abstract: The TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) mission comprisses two nearly identical satellites: TerraSAR-X (TSX, launched in 2007), and TanDEM-X (TDX, launched in June 2010). The primary objective of the mission is to generate a worldwide and consistent digital elevation model (DEM) with an unprecedented accuracy. During the first 3 months after its launch, the TDX satellite was tested and calibrated in monostatic configuration with both satellites flying in 20 km along-track distance, and it was proven that the system and acquisition with both satellites flying in 20 km along-track distance, and it was proven that the system and acquisition performance is almost identical to TSX. Both satellites were then brought into close formation of a few hundred meters distance to begin the bistatic commissioning phase. Since then, TSX and TDX have acted as a large single-pass radar interferometer, which overcomes the limitations imposed by repeat-pass interferometry and allow the acquisition of highly accurate cross-and along-track interferograms. In December 2010, TanDEM-X began with operational global acquisition: bistatic and monostatic SAR images are simultaneously acquired in stripmap mode and processed to interferograms, from which a global DEM is derived. The key parameter is estimating interferometric performance is the coherence, which is deeply evaluated in this paper. The impact of different decorrelation sources as well as the performance stability over time is investigated by means of statistical analyses and dedicated acquisitions on defined test sites, demonstrating the outstnding interferometric capabilities of the TanDEM-X mission.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57621
Title: TanDEM-X calibrated Raw DEM generation
Author: Cristian Rossi, Fernando Rodriguez Gonzalez, Thomas Fritz, Nestor Yague-Martinez, Michael Eineder
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: TanDEM-X, Raw DEM, InSAR processing, SAR stereo-radargrammetry, Absolute phase offset estimation, DEM calibration
Abstract: The TanDEM - X mission successfully started on June 21st 2019 with the launch of the German radar satellite TDX, placed in orbit in close formation with the TerraSAR -X (TSX) satellite, and establishing the first spaceborne bistatic interferometer. The processing of SAR raw data to the Raw DEM is performed by one single processor, the Integrated TanDEM-X Processor (ITP). The quality of the Raw DEM is a fundamental parameter for the mission planning. In this paper, a novel quality indicator is derived. It is based on the comparison of the interferometric measure, the unwrapped phase, and the stereo-radargrammetric measure, teh geometrical shifts computed in the coregistration stage. By stating the accuracy of the unwrapped phase, it constitutes a useful parameter for the determination of problematic scenes, which will be resubmitted to the dual baseline phase unwrapping processing chain for the mitigation of phase unwrapping errors. The stereo-radargrammetric measure is also operationally used for the Raw DEM absolute calibration through an accurate estimation of the absolute phase offset. This paper examines the interferometric algorithms implemented for the operational TanDEM - Raw DEM generation, focusing particulalry on its quality assessment and its calibration.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57620
Title: Bistatic system and baseline calibration in TanDEM -X to ensure the global digital elevation model quality
Author: Jaime Hueso Gonzalez, John Mohan Walter Antony, Markus Bachmann, Gerhard Krieger, Manfred Zink, Dirk Schrank, Marco Schwerdt
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: Accuracy, Calibration, digital, interferometer, SAR, satellite, space
Abstract: TanDEM-X is an operational satellite mission with the goal of generating a high quality global digital elevation model (DEM) based on synthetic aperture radar (SAR) interferometry in X-band. In order to ensure the quality of the DEM, the differential range measurements and knowledge of the interferometric baseline have to be extremely accurate. In this paper, the bistatic system calibration strategy implemented in TanDEM-X to achieve the desired DEM quality will be described, focusing on the baseline calibration procedure. The results of the tests, which were performed in parallel to the operational DEM acquisition, verify the suitability of this approach.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57619
Title: Automatic generation of 2.5 D terrain models without occluding routes of interest
Author: Hao Deng, Liqiang Zhang, Jingtao Ma, Liang Zhang, and Dong Chen
Editor: Russell G Congalton
Year: 2012
Publisher: ASPRS, Vol 78, No 11, November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering and Remote Sensing
Keywords: Disocclusion views, temporal coherence
Abstract: When a car drives in mountainous regions, the views based on conventional perspective projection often suffer from features of interest being occluded. We propose a method for generating disocclusion views in mountainous regions. The terrain is segmented to build a potential set of occluders; and then a optimized viewpoint is determined, and elevations are rearranged. To obtain a smooth deformed terrain, a smooth displacement function is introduced to deform terrain, a smooth displacement function is introduced to deform the level-of -detail terrain models. Compared with previous methods, the merit of this study lies in automatically generating disocclusion views with temporal coherence, while keeping the details of the deformed terrain the same as the original terrain. Expeirments performed on the 4098 pixel x 4098 pixel mountainous terrain landscape prove that the disocclusion views can achieve 42 to 58 frames/second. Moreover, the shapes of the features of interest on the driving route without occlusion and the spatial configuration of geographical landmarks in its neighborhood can be easily recognized.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57618
Title: Integrating landsat-7 imagery with physics-based models for quantitative mapping of coastal waters near river discharges
Author: Nima Pahlevan, Alfred J Garrett, Aaron D Gerace, and John R Schott
Editor: Russell G Congalton
Year: 2012
Publisher: ASPRS, Vol 78, No 11, November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering and Remote Sensing
Keywords: Landsat Data Continuity Mission (LDCM),Enhanced Thematic Mapper Plus (ETM+), Look-Up-Tables (LUTs), root-mean-squared-error (RMSE)
Abstract: Remote sensing has traditionally been used to retrieve water constituents by establishing a relationship between in situ measured quantities and image-derived products. Motivated by the dramatically improved potential of the Landsat Data Continuity Mission (LDCM), this paper describes a different approach for water constituent retrieval where both thermal and visible spectral bands of the Enhanced Thematic Mapper Plus (ETM+) instrument on board Landsat-7 are utilized. In this effort, Landsat data is integrated with a 3D hydrodynamic model to obtain profiles of particles and dissolved matter in the near shore zone in the vicinity of two river discharges. The procedure is based upon performing many hydrodynamic simulations by adjusting input environmental/ physical variables and generating Look-Up-Tables (LUTs). The best match, obtained using optimization, demonstrated an average root-mean-squared-error (RMSE) of 0.68 percent, i.e., 0.0068 reflectance units, calculated over the two river plumes. It is concluded that calibraing a physical-based model using the Landsat-7 imagery can provide a more lucid insight into the dynamics of spatially non-uniform waters.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57617
Title: Mapping nighttime flood from MODIS observations using support vector machines
Author: Rui Zhang, Donglian Sun, Yunyue Yu, and Mitchell D Goldberg
Editor: Russell G Congalton
Year: 2012
Publisher: ASPRS, Vol 78, No 11, November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering and Remote Sensing
Keywords: Moderate Resolution Imaging Spectroradiometer (MODIS), support vector machines (SVM)
Abstract: This work proposes a nighttime flood mapping method for Moderate Resolution Imaging Spectroradiometer (MODIS) data. Brightness temperatures at 3.9 ? m, and 11 ? m channels (BT 3.9 and BT 11, respectively) and differences of brighness temperatures between 3.9 ? m and 4.0 ?m and between 11?m and 12 ?m (BT 3.9 -BT4.0 and BT 11-BT 12, respectively) are used to identify nighttime water pixels by a support vector machines (SVM) classifier. Prominent flood locations are detected by a change detection process using a reference water-land map. To test the effectivenss of the proposed method, two flood cases caused by heavy rains were chosen as trial scenarios. The nighttime mapping results are validated with the flood maps, which are obtained from the visual interpretation based on the daytime flood identification results. The experimental results indicate that the proposed method is effective for the delineation of inundated areas with standing water during the nighttime.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57616
Title: Aerial image mosaicking with the aid of vector roads
Author: Dongliang Wang, Youchuan Wan, Jianhua Xiao, Xudong Lai, Wenli Huang, and Jinghong Xu
Editor: Russell G Congalton
Year: 2012
Publisher: ASPRS, Vol 78, No 11, November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering and Remote Sensing
Keywords: vector roads, raster-based representative, vector - based approach
Abstract: This paper proposes a novel approach for using vector roads to aid in the generation of seamline networks for aerial image mosaicking. A representative seamline is extracted as follows. First, the straight skeleton of the overlapping area of adjacent images is extracted. Second, vector roads in the overlapping regions are overlaid with the extracted skeleton to build a weighted graph G (V,E). Dijkstra ' s algorithm is applied to find the lowest-cost path that connects two intersections of the polygons of two adjacent images. The lowest-cost path is considered as a seamline candidate. Finally, the seamline candidate is refined by considering its surrounding pixels. The refined seamline is employed as the final seamline. The resultant seamline is employed as the final seamline. The resultant seamlines commonly follow the centerlines of roads as much as possible, and the mosaic image appears more seamless. Moreover, the vector-based approach is typically more efficient than the existing raster-based approaches: the vector-based approach is nearly ten times faster than a raster-based representative.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57615
Title: A method for detecting windows from mobile Lidar data
Author: Ruisheng Wang, Frank P Ferrie, and Jane Macfarlane
Editor: Russell G Congalton
Year: 2012
Publisher: ASPRS, Vol 78, No 11, November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering and Remote Sensing
Keywords: Mobile lidar, mutiple georeferenced sensors
Abstract: Mobile lidar (light detection and ranging) data collection is a rapidly emergining technology in which multiple georeferenced sensors (e.g., laser scanners cameras) are mounted on a moving vehicle to collect real world data. The photorealistic modeling of large-scale rela world scenes such as urban environments has become increasingly interesting to the vision, graphics, and photogrammetry communities. In this paper, we present an automatic approach to window and facade detection from mobile lidar data. The proposed ,method combines bottom-up with top-down strategies to extract facade planes from noisy lidar point clouds. The window detection is achieved through a two-step approach: potential window point detection and window localization. The facade pattern is automatically inferrd to enhance the robustness of the window detection. Experimental results on six datasets result in 71.2 percent and 88.9 percent in the first two datasets, 100 percent for the rest four datasets in terms of completeness rate, and 100 percent correctness rate for all the tested datasets, which demonstrate the effectiveness of the proposed solution for planar facades with rectilinear windows. The application potential includes generation of building facade models with street-level details and texture synthesis for producing realistic occlusion-free facade texture.
Location: TE 12, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57614
Title: The evaluation of environmental hazards of Urban squatter settlements based on GIS, The case study: North squatter settlements of Tabriz city, Iran
Author: Dr Saeed Maleki, Dr Akbar Asghari Zamani
Editor: Prof Natarajan Gajendran
Year: 2012
Publisher: Indian Society for Education and Environment, Vol 5, Issue 12, December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Indian Journal of Science and Technology
Keywords: Environmental hazards, squatter settlements, GIS, Tabriz city, Iran
Abstract: In the past decades urban areas of Iran have grown very rapidly. According to statistics bureau of Iran, in 1996, 61.31% of the population lived in 614 urban centers-some 36 million. By 2020, this figure is estimated to rise to 80%. This rise in urban population has resulted in continuous creation and growth of squatter settlements and in spreading of civil services until the breaking point. Serious shelter shortages, overcrowding, decreasing of the starndards of public health and sanitary services, deterioration in the quality of living are the bitter fruits of the urban expansion in Iran. In this article based on a broad field study, we try to show some of physical environmental bitters which informal settlements in Iranian cities are faced with, especially in Tabriz city as a fourth biggest metropoliltan area based on GIS analysis. This research is prepared in 3 parts: Part 1 the case of Tabriz city, Part 2: physical and man-made hazards, Part 3: Evaluation of land tenures and dwellings.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57613
Title: Salinity and seawater intrusion into the ground water
Author: Funda Dokmen
Editor: Prof Natarajan Gajendran
Year: 2012
Publisher: Indian Society for Education and Environment, Vol 5, Issue 12, December 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Indian Journal of Science and Technology
Keywords: Borehole and pumping, Catchments management, ecohydrology, reservoir, water quality
Abstract: Many shallow and deep wells were dug on the coastal plains to meet drinking water needs, and to satisfy industrial and irrigation requirements of private establishments. The excess water drawn for drinking and irrigating purposes affects the water reservoir resulting in a lowering of the "water table". Consequently, there is intrusion of seawater into the reservoir, which results in salinity problems. The negative effects of using salt water on agricultural crops and seawater intrusion occurred because of excessive abstraction of water from the bore-holes located in the coastal plains of Hersek, Taskopru, and Altinova and Yalova region, Turkey. Previous studies have shown that the depth of shallow wells ranged from 5 m to 20 m in depth and deep wells ranged between 16 m and 243 m. Seawater intursion was found withing a 1km radius of the coastal line of the research area.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57612
Title: Reproductive assurance through unusual autogamy in hte absence of pollinators in Passiflora edulis (Passion fruit)
Author: K R Shivanna
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 103, No 9, 10 November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Autogamy, Passiflora edulis, Passion fruit, reproductive assurance
Abstract: Passiflora edulis (passion fruit), a native of Brazil, is widely grown in frost-free areas around the world. In its native habitat and many other areas, the species is self-incompatible and carpenter bees are the effective pollinators. In India, it is cultivated in North East and southern states. In two of the populations of P. edulis F . flavicarpa (yellow passion fruit) in Karnataka, there was good fruit set, although there were no effective pollinators. Studies were carried out on reproductive ecology of yellow passion fruit to understand the mode of fruit set in the absence of pollinators and the breeding system. Although several floral visitors, Apis cerana, Trigona sp. and an ant (Camponotus sp.) visited the flowers, they were all nectar robbers and not the pollinators. There is a unique autonomous self-pollination, involving hte movement of anthers and stigmas, during flower opening which provides reproductive assurance to the species even in the absence of pollinators. The populations used in the present study are self-compatible. Thus, the species is able to produce constant fruit set even when teh population size is small and pollinators are absent; evolution of these features seems to be the main factor for its wide distribution around the world.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57611
Title: Attributable deaths from smoking in the last 100 years in India
Author: Pranay G Lal, Nevin C Wilson and Prakash C Gupta
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 103, No 9, 10 November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Bidis, cigarettes, premature mortality smoking, tobacco
Abstract: Tobacco use, and in particular smoking, is the largest cause of prventable death among adults in India, as it is globally. Bidi, an indigenous, leaf-rolled cigarette made from coarse sun-cured tobacco, tied with a coloured string at one end, is the dominant form among all smoked products. More than eigth to ten bidis are consumed for every cigarette in India. We present mortality estimates from smoking cigarettes and bidis manufactured over the last 100 years in India. There are currently no estimates of mortality, over a period of time, in India that can be directly attributed to cigarettes/bidis manufactured in the country. The objective of this study is to estimate the number of premature deaths that can be attributable to cigarette and bidi manufactured and consumed over the last 100 years in India. Nearly 4.52 trillion cigarettes and 40.3 trillion bidis have been produced between 1910 and 2010, which are estimated to be responsible for nearly 100 million premature deaths (in which bidis contributed 77 million deaths) in adult men of 35 years. Some of these deaths will occur up to the middle of the century. These estimates are derived from the most conservative datasets and yet present alarming mortality estimates. This communication calls for greater emphasis on epidemiological research and a review of existing tobacco control measures in India, which together need to inform measures needed for reducing tobacco use and restricting the proliferation of the tobacco industry.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57610
Title: A novel haloarchaeal lineage widely distributed in the hypersaline marshy environment of Little and Great Rann of Kutch in India
Author: Manesh Thomas, Kamal K Pal, Rinku Dey, Anil K Saxena and Sahilesh R Dave
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 103, No 9, 10 November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Diversity, haloarchaea, marshy environment, novel lineage, phylogeny
Abstract: Archaea (Archaebacteria) are a phenotypically diverse group of microorganims distributed mainly in extreme environments throughout the world. To study the community of archaea present in the extreme salty marshes of the Rann of Kutch, Gujarat, India culture-dependent approach was employed for isolating archaea by mimicking extreme hypersaline environment and 25 extreme halophilic archaea were obtained. Phylogenetic analysis revealed the presence of a number of uncultivated and unidentified members of archaea among the isolates present. Phylogenetic analysis involving the sequence data of 16S rRNA of 25 haloarchaeal isolates, keeping Methanospirillium hungatei DSM864 (M60880) as the out-group, also identified a novel lineage of three isolates. The 16S rRNA sequences of the strains 3A1-DGR, H9-DGR and 2ANA-DGR showed less than 93% similarity with the available known type strains and these three strains belong to a distinct novel lineage within the family Halobacteriaceae, near an uncultivated environmental cluster.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57609
Title: Regulating the dual-use and dual-impact life science research: influenza virus versus biotech crops
Author: P K Gupta
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 103, No 9, 10 November 2012
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Bacillus thuringensis, dual-use and dual-impact, genetically modified crops, recombinant DNA
Abstract: Dual-use research of concern (DURC) is the research that is intended for legitimate benefits, but also carries a risk of being misused. In this article, the work related to regulation of dual-use influeza virus research involving genetic engineering of the subtype H5N1 has been compared with the research involving regulation of biotech crops including Bt cotton and Bt brinjal in India, which the author likes to describe as dual-impact research of concern. The growth of biotech crops globally has been briefly described to highlight that no harmful effects of any biotech crop grown and utilized during the last more than 15 years have been reported. The contrast between the responsible manner in which scientists dealt with the regulation of DURC and the manner in which the civil societies and some NGOs have been spreading misinformation, thus creating obstacles in commercialization of biotech crops meant for public good is revealing indeed. Therefore, major efforts are needed on the part of scientists and the media to develop good communication system involving newspapers, extension workers and TV programmes, which should highlight the merits and safety of biotech crops. Scientists should also work hard to convince the government that there is a need to reduce the burden of regulation for biotech crops, so that the benefit of this technology could reach the masses.
Location: TE 15, Biologicalsciences Building, IISc
Literature cited 1: None
Literature cited 2: None
ID: 57608
Title: Gender and climate resilient agriculture: an overview of issues
Author: G Nirmala and B Venkateswarlu
Editor: P Balaram
Year: 2012
Publisher: Current Science Association, Vol 103, No 9, 10 November 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