ID: 58023
Title: Estimation of Indian coastal areas inundated into the sea due to sea-level rise during the 20th century
Author: S Nayak, M Mandal, A Adhikari, R Bhatla
Editor: P Balaram
Year: 2013
Publisher: Current Science Association, Vol 104, No 5, 10 March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE15, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58022
Title: What should we know about the famous Iris data?
Author: Marcin Kozak and Barbara Lotocka
Editor: P Balaram
Year: 2013
Publisher: Current Science Association, Vol 104, No 5, 10 March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE15, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58021
Title: Conserve the endangered science, taxonomy
Author: Pitchaimuthu Mariappan, Chellam Balasundaram
Editor: P Balaram
Year: 2013
Publisher: Current Science Association, Vol 104, No 5, 10 March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE15, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58020
Title: Policy views on conservation and management of wetlands
Author: D Balasubramanian, K Arunachalam, A Arunachalam
Editor: P Balaram
Year: 2013
Publisher: Current Science Association, Vol 104, No 5, 10 March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: TE15, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58019
Title: Wireless sensor networks and its application to three-phase induction motors
Author: Prof Rabi Naryana Parida, Er Bibhu Prasad Nanda and Prof Jibanananda Mishra
Editor: Gopal Krishna Anand
Year: 2013
Publisher: A Chary Publication, Vol 53, No 3, March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Electrical India
Keywords: induction motors, wireless sensors, wireless sensor net-works (WSN)
Abstract: A commonly used technique for the detection of faults in large three-phase induction motors is to measure the supply current to the motor and analyze the signal spectrum. This technique is well established and has been shown to be indicative of a faulty condition. However, current signature analysis is usually used by very skilled technicians using expensive equipment. A cost effective condition monitoring technique is needed for smaller motors (those smaller than 100 HP). A motor ' s heat signature tells more about its quality and condition. For heavy-duty motors, it is very important to detect overheating because hot windings deteriorate rapidly. This article explores the possibilities of using wireless sensors inside the motor. Wireless sensors are gaining popularity in condition monitoring applications because of their relatively low cost and ease of installation. This article proposes a system of condition monitoring of the three-phase induction motor using wireless sensor net-works (WSN) to measure the temperature and the vibration signals. The sensor nodes are placed on the rotor and the stator. The data acquisition is accomplished at a base station located at a distance of 6 feet. Issues related to electromagnetic interferences between the wireless devices and the magnetic fields present within the motor are investigated.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58018
Title: Sensitivity analysis of single-phase induction motor from its equivalent circuit parameters
Author: C S Indulkar
Editor: Gopal Krishna Anand
Year: 2013
Publisher: A Chary Publication, Vol 53, No 3, March 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: Electrical India
Keywords: single-phase induction motor
Abstract: A computer simulation of the performance of a single-phase induction motor from its equivalent circuit is carried out, and the graphs of slip, input power, stator current, power factor, and efficiency against output power are presented. The nomalized sensitivity values of the single-phase motor performance variables with respect to its equivalent circuit parameters when operating near its full load are also presented. The study reveals the effects of each equivalent circuit parameter, applied voltage and frequency on the motor input power, power factor, output power, output torque, and efficiency respectively.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58017
Title: Global seamline networks for orthomosaic generation via local search
Author: Steven Mills, Philip McLeod
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Aerial mosaic generation, Image processing, Graph algorithms, Optimal path finding, Orthomosaic Generation, Seamline networks
Abstract: A novel method for establishing a seamline network for orthomosaic generation is presented. The seamlien network determines the region of the mosaic allocated to each of the original images. Our method allows for optimal network vertices to be selected while avoiding a combinatorial optimisation task. The computational requirements (time and storage) of our proposed method are linear in the number of images. Seamlines between vertices are found using a graph-based approach which finds shortest paths, subject to a constraint which minimises the maximum cost of any single edge. Experiments on synthetic and real-world data sets illustrate the value of the approach compared to native vertex selection and recently proposed methods.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58016
Title: Monitoring seasonal snow dynamics using ground based high resolution photography (Austre Lovenbreen, Svalbard, 790N)
Author: E Bernard, J M Freidt, F Tolle, M Griselin, G Martin, D Laffly, C Marlin
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Ground based camera, Snow cover dynamics, In situ sensing, Geometric correction, digital camera, Svalbard, Glacier, High temporal resolution
Abstract: Arctic glaciers are reliable indicators of global climate changes. However, monitoring snow and ice dynamics in Arctic regions is challenging: some fast but key events can be missed since they are short in time but significant in the hydrological budget.
In the context of long term monitoring with high temporal and spatial resolutions of the snow cover dynamics, automated digital cameras were installed around the Austre Lovenbreen glacier basin (Spitsbergen, Norway, 790N). Despite data losses due to rough weather conditions and control electronics failure, a dataset of 2411 pictures (out of an expected 3294) was gathered over a 1 year hydrological period to assess the snow coverage of the glacier as a function of time with daily resolution. 73% of the total number of expected images was thus recorded, with gaps associated with temporary electronics or data storage failure.
The six camera stations oriented so as to observe the glacier itself provide a surface coverage of 96%. Futhermore, geometric corrections of the pictures, using reference ground control points lcoated on the glacier through GPS receivers, yield a quantitiative information from initially qualitative images. Projecting the resulting mosaic of the images gathered from six cameras on a GIS allows for the precise monitoring of ice-related processes, and especially the snow coverage evolution over time. This paper summarizes our current understanding of such dynamics, based on the analysis of daily mosaics of images allowing for the observation of both long term evolution on the seasonal scale and the short term events on a weekly scale. Such results demonstrated over one typical full hydrological season (April-October 2009) that snow coverage evolves following discrete steps, either due to water precipitation or warm events, with a snow coverage ranging from 100% (april) to 37% (september).
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58015
Title: Perception - based shape retrieval for 3D building models
Author: Man Zhang, Liqiang Zhang, P Takis Mathiopoulos, Yusi Ding, Hao Wang
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: 3D building model, shape matching, perception, retrieval
Abstract: With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at thier main axes, but appear similar when one of them is rotated. TO resolve this problem, we present a novel upright - based normalization method which not only correctly rotates such building models but also greatly simplifies and accelerates the abstraction and the matching of building models ' shape descriptors. Moreover, the abundance of architectural styles signifcantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance evaluation results have verified that the proposed methodology does not sacrifice the matching accuracy while significantly improves the efficiency when matching 3D building models.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58014
Title: Individual tree biomass estimation using terrestrial laser scanning
Author: Ville Kankare, Markus Holopainen, Mikko Vastaranta, Eetu Puttonen, Xiaowei Yu, Juha Hyyppa, Matti Vaaja, Hannu Hyyppa, Petteri Alho
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Terrestrial laser scanning, Aboveground biomass, Individual tree, features, stem volume, stem curve
Abstract: Determination of stem and crown biomass requires accurate measurements of individual tree stem, bark, branch and needles. These measurements are time-consuming especially for mature trees. Accurate field measurements can be done only in a destructive manner. Terrestrial laser scanning (TLS) measurements are a viable option for measuring the reference information needed. TLS measurements provide dense point clouds in which features describing biomass can be extracted for stem form and canopy dimensions. Existing biomass models do not utilise canopy size information and therefore TLS-based estimation methods should improve the accuracy of biomass estimation. The main objective of this study was to estimate single-tree-level aboveground biomass (AGB), based on models developed using TLS data. The modelling dataset included 64 laboratory-measured trees. Models were developed for total AGB, tree stem-, living branch- and dead branch biomass. Modellilng results were also compared with existing individuals tree-level biomass models and showed that AGB estimation accuracies were improved, compared with those of existing models. However, current biomass models based on diameter-at-breast height (DBH), tree height and species worked rather well for stem- and total biomass. TLS-based models improved estimation accuracies, especially estimation of branch biomass. We suggest the use of stem curve and crown size geometric measurements from TLS data as a basis for allometric biomass models rather than statistical three-dimensional point metrics, since TLS statistical metrics are dependent on various scanning parameters and tree neighbourhood characteristics.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58013
Title: Super-resolution image analysis as a means of monitoring bracken (Pteridium aquilinum) distributions
Author: Jennie Holland, Paul Aplin
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Bracken, Super-resolution, classification, monitoring, vegetation, scale
Abstract: The bracken (Pteridium aquilinum) fern in environmentally significant due to its great abundance and swift colonisation, and its perception as a problem plant in degrading agricultural or ecologically sensitive land. Various attempts have made to map bracken using remote sensing, but these have proved relatively unsucceful, often apparently constrained by the lack of spatial detail associated with medium spatial resolution satellite sensors such as the Landsat series. In this study, bracken was characterised using a combination of 30 m Landsat sensor imagery and 4 m IKONOS imagery. Different classification techniques were compared, including hard maximum likelihood classification and a super-resolution approach comprising soft classification and sub-pixel contouring. These techniques were applied to a range of image dates, including summer, winter and multitemporal images. Image analysis was supported by extensive field data collection, comprising both a land cover survey and stakeholder interviews. For the hard classified Landsat sensor imagery, the summer image proved least able to characterise bracken, due largely to the spectral similarity between (green) growing bracken and grasses and other vegetation. The winter images were more successful for identifying bracken due to the strong contrast between dead (brown/red) bracken and other vegetation. However, the multitempral Landsat image was considerably more accurate than any of the single data images. The hard classified IKONOS image was more accurate overall than the Landsat sensor images for classifying land cover. Surprisingly, though, it was not comprehensively more accurate for mapping the bracken class. Notably, the producers accuracy of bracken was lower for the IKONOS image than the Landsat sensor images. This suggests image spatial resolution, although influential on the success of bracken characterisation, is not necessarily the sole or main determinant of classification accuracy. Also important are the temporal nature of image acquisition (here the multitemporal Landsat sensor image proved of considerable benefit) and the spectral characteristics of the imagery (here IKONOS ' s four visible and near infrared spectral wavebands proved limited compared to the Landsat sensor ' s six visible, near and shortwave infrared bands). Following soft classification of the multitemporal Landsat image, super-resolution sub-pixel contouring was applied to identify the boundary of bracken patches. Predicted bracken boundaries were assessed against actual boundaries identified using field observation and IKONOS imager interpretation. For comparison, the bracken boundaries identified through hard classification (i.e. using pixel edges) were also assessed against the actual boundaries. Overall, the spatial accuracy of the super-resolution approach proved considerably higher than that of hard classification.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58012
Title: Combination of overlap-driven adjustment and Phong model for LiDAR intensity correction
Author: Qiong Ding, Wu Chen, Bruce King, Yanxiong Liu, Guoxiang Liu
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Airborne laser scanning, intensity, least squares, overlapping strips, reflection
Abstract: Airborne laser scanning LiDAR systems deliver not only geometric (X,Y,Z) information of the scanned surfaces but also the returned intensity of the laser pulse. Recetn studies have shown the potential of using intensity data for many applications. However, there are limitations in using the raw intensity data because of radiometric system bias, reflectance noise and variations between adjacent strips. To overcome these limitations, a three-step LiDAR intensity correction algorithms is proposed. Following corrections for environmental and surface effects, an overlap-driven least-squares adjustment model that does not rely on the selection of homologous points minimizes intensity differences in the overlap area of strips. Finally, the Phong reflection model, which describes both diffuse and specular reflectance, is used to attenuate the effects of strong reflections that typically occur over wet or water dominated areas. The algorithm was applied to a multi-strip LiDAR dataset that covers wetlands in the estuary of the Yellow River, People ' s Republic of China. Results demonstrated a significant reduction in radiometric differences in the overlap areas, and strong specular reflections in the nadir regions were reduced. Objects which were obscured by the specular reflection in the original intensity data were clearly identifiable after the adjustment.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58011
Title: Mapping the distribution of ferric iron minerals on a vertical mine face using derivative analysis of hyperspectral imagery (430-970 nm)
Author: Richard J Murphy, Sildomar T Monteiro
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Mining, Iron ore, Remote sensing, Hyperspectral, derivative analysis, banded iron formation
Abstract: Hyperspectral imagery is used to map the distribution iron and separate iron ore from shale ( a waste product) on a vertical mine face in an open-pit mine in the Pilbara, Western Australia. Vertical mine faces have complex surface geometries which cause large spatial variations in the amount of incident and reflected light. methods used to analyse imagery must minimise these effects whilst preserving any spectral variations between rock types and minerals. Derivative analysis of spectra to the 1st-, 2nd - and 4th- order is uksed to do this. To quantify the relative amounts and distribution of iron, the derivative spectrum is integrated across the visible and near infrared spectral range (430-970 nm) and over those wavelength regions containing individual peaks and troughs associated with specific iron absorption features. As a test of this methodology, results from laboratory spectra acquired from representative rock samples were compared with total amounts of iron minerals from X-ray diffraction (XRD) analysis. Relationships between derivatives integrated over the visible near-infrared range and total amounts (% weight) of iron minerals were strongest for the 4th- and 2nd - derivative (R2 = 0.77 and 0.74, respectively) and weakest for the 1st - derivative (R2 =0.56). Integrated values of individual peaks and troughs showed moderate to strong relationships in 2nd - (R2 =0.68-0.78) and 4th - derivative (R2 = 0.49-0.78) spectra. The weakest relationships were fouind for peaks or troughs towards longer wavelength.
The same derivative methods were then applied to imageyr to quantify relative amounts of iron minerals on a mine face. Before analyses, predictions were made about the relative abundances of iron in the different geological zones on the mine face, as mapped from field surveys. Integration of the whole spectral curve (430-970 nm) from the 2nd - and 4th derivative gave results which were entirely consistent with predictions. Conversely, integration of the 1st-derivative gave results that did not fit with predictions nor distinguish between zones with very large and small amounts of iron oxide.
Classified maps of ore and shale were created using a simple level-slice of the 1st - derivative reflectance at 702, 765 and 809 nm. Pixels classified as shale showed a similar distribution to kaolinite (an indicator of shales in the region), as mapped by the depth of the diagnostic kaolinite absorption feature at 2196 nm. Standard statistical measures of classification performance (accuracy, precision, recall and the Kappa coefficient of agreement) indicated that nearly all of the pixels were classified correctly using 1st-derivative reflectance at 765 and 809 nm. These results indicate that data from the VNIR (430-970 nm) can be used to quantify, without a priori knowledge, the total amount of iron minerals and to distinguish ore from shale on vertical mine faces.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58010
Title: A review of EO image information mining
Author: Marco Quartulli, Igor G Olaizola
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Remote sensing, Database, Content - based image retrieval, EO minig, Information retrieval
Abstract: We analyze the star of the art of content-based retrieval in Earth observation image archives focusing on complete systems showing promise for operational implementation. The different paradigms at the basis of the main system families are introduced. The approaches takne are considered, focussing in particular on the phases after primitive feature extraction. The solutions envisaged for the issues related to feature simplification and synthesis, semantic labeling are reviewed. The methodologies for query specification and execution are evaluated. Conclusions are drawn on the state of published research in Earth observation (EO) mining.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None
ID: 58009
Title: Joint estimation of moving target reflectivity and velocity via AT-InSAR systems based on complex interferometric data
Author: Alessandra Budillon, Vito Pascazio, Gilda Schirinzi
Editor: George Vosselman
Year: 2013
Publisher: Elesevier, Vol 75, January 2013
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Synthetic aperture radar, Along-track interferometry, Velocity estimation
Abstract: In this paper a technique for the joint estimation of the complex reflectivity and of the radial velocity of ground moving targets, by means of Along-Track Interferometric Synthetic. Aperture Radar (AT-InSAR) systems, is presented. It is essentially based on statistical estimation techniques and exploits the complex interferometric SAR images, contrarily to other conventional AT-InSAR methods, which estimate the target radial velocity exploiting only the interferometric phases. The performances of the method are evaluated both for single baselien and for dual-baseline satellite systems. In terms of Cramer Rao Lower Bounds and of Root Mean Square Errors obtained in numerical experiments, with reference to all target parameters to be estimated, which are the amplitude and phase of the target reflectivity and the target radial velocity. It is shown that for single baseline systems the obtained radial velocity estimation accuracy is comparable with the one achievable with AT-InSAR methods exploiting phase-only data, and is very high for high values of signal to cluster ratio. For dual-baseline systems, instead, the use of amplitude and phase data allows a performance significnatly better than the one achievable exploiting phase-only data. Moreover, in the dual baseline case, high velocity estimation accuracy can be obtained also with lower signal to clutter ratios.
Location: TE12, New Biological Sciences, IISc
Literature cited 1: None
Literature cited 2: None