ID: 54247
Title: Object-based image analysis through nonlinear scale-space filtering
Author: Angelos Tzotsos, Konstantinos Karantzalos, Demetre Argialas
Editor: George Vosselman
Year: 2011
Publisher: Elsevier, Vol 66, No 1, January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: ISPRS Journal of Photogrammetry and Remote Sensing
Keywords: Automation, Analysis, Simplification, Segmentation, Classification
Abstract: In this research, an object-oriented image classification framework was developed which incorporates nonlinear scale-space filtering into the multi-scale segmentation and classification procedures. Morphological levelings, which posses a number of desired spatial and spectral properties, were associated with anisotropically diffused markers towards the construction of nonlinear scale spaces. Image objects were computed at various scales and were connected to a kernel-based learning machine for the classification of various earth-observation data from both active and passive remote sensing sensors. Unlike previous object-based image analysis approaches, the scale hierarchy is implicitly derived from scale-space representation properties. The developed approach does not require the tuning of any parameter-of those which control the multi-scale segmentation and object extraction procedure, like shape, color, texture, etc. The developed object-oriented image classification framework was applied on a number of remote sensing data from different airborne and spaceborne sensors including SAR images, high and very high resolution panchromatic and multispectral aerial and satellite datasets. The very promising experimental results along with the performed qualitative and quantitative evaluation demonstrate the potential of the proposed approach.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54246
Title: Utilizing temporally invariant calibration sites to classify multiple dates and types of satellite imagery
Author: Joe Fortier, John Rogan, Curtis E Woodcock, and Daniel Miller Runfola
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: retrospective mapping, satellite imagery
Abstract: Mapping past time periods (retrospective mapping) using remotely sensed data is hindered by a lack of coincident calibration and validation information. The identification of features of same ground cover invariant across time and their use as calibration and validation data addresses this challenge by: (a) streamlining the process of image calibration for multiple dates, and (b) allowing each image to generate its own spectral signature. This study investigates the use of temporally invariant calibration and validation data to map land-cover in Massachusetts, employing five satellite images collected from five separate dates and different sensors. The results indicate that this technique can be used to produce land cover classifications of similar overall map accuracy to published mapping studies. Classification accuracy using this method is highly dependent on the characteristics (radiometric, spectral, and spatial) of the satellite imagery.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54245
Title: A genetic algorithm approach to moving threshold optimization for Binary change detection
Author: Jungho Im, Zhenyu Lu, and John R Jensen
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: genetic algorithm (GA), moving threshold window (MTW), bi-temporal QuickBird imagery, ymmetric threshold window (STW)
Abstract: This study investigated the use of a genetic algorithm (GA) approach, a widely used optimization method, to identify optimum thresholds for remote sensing-based binary change detection. Automated GA-based calibration models using a moving threshold window (MTW) were developed and tested using a case study. Two sets of the bi-temporal QuickBird imagery were used to evaluate the new optimizatin models. The GA-based models using MTW were free from the assumption of symmetry of thresholds for difference-or ratio-type of change-enhanced images, unlike traditional binary change detection methods, allowing more flexibility and efficiency in selecting optimum thresholds. Exhaustive search techniques using symmetric threshold window (STW) and MTW were evaluated for comparison. The stability of the GA-based models in terms of accuracy variation was also examined. The GA-based calibration models successfully identified optimum thresholds without a significant decrease in accuracy. The GA-based models using MTW outperformed the GA-based model using STW in both calibration and validation, revealing that optimum thresholds tended to be asymmetric. Multiple change-enhanced images generally resulted in better performance than single change-enhanced images based on the GA-based models.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54244
Title: Validation of ASTER GDEM for the area of Greece
Author: N Chrysoulakis, M Abrams, Y Kamarianakis, and M Stanislawski
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), Global Digital Elevation Model (GDEM), Geodetic Control Points (GCP)
Abstract: The ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) Global Digital Elevation Model (GDEM), which was released in June 2009, provides elevation data for over 99 percent of Earth ' s land area. GDEM was found to contain significant anomalies mainly caused by residual clouds in the ASTER scenes, or by the algorithm used to generate the final GDEM from the variable number of individual DEMs. In this paper, the GDEM, for the whole area of Greece was validated by comparing it with reference DEMs with higher resolution derived either from aerial stereo imagery, or from ASTER raw data analysis; as well as with elevation values provided by a number of Geodetic Control Points (GCP) and GPS measurements. The vertical accuracy (at 95 percent confidence) was calculated to be more than 30 m (RMSE = 16.01 m) when compared to teh GCPs, whereas the vertical accuracy was calculated around 20 m (RMSE = 11.08 m) when compared with the GPS derived elevations. It can be therefore stated that the current version of ASTER GDEM overall does not meet its pre-production estimated vertical accuracy of 20 m at 95 percent confidence over Greece, however, it can be used in several applications, such as topographic analysis, hydrological and geomorphological modeling, landscape visualization, and energy balance studies.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54243
Title: Sub-canopy soil moisture modeling in n-Dimensional spectral feature space
Author: Abduwasit Ghulam, Timothy M Kusky, Tashpolat Teyip, and Qiming Qin
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: Extended Fourier Amplitude Sensitivity Test (eFAST), Enhanced Thematic Mapper Plus (ETM +), Moderate Resolution Imaging Spectroradiometer (MODIS)
Abstract: This paper attempts to quantify soil moisture in various canopy cover conditions using n-dimensional spectral signatures, including land surface temperature, vegetation index, albedo, and others. First, the feature vector between the pixels and various moisture contents was indentified. Normalization of the varying distance from a user-defined initial state to any pixel location, and coefficients related with n-dimensional spectral feature space were calculated, assigning weights to each parameter. Then, a soil moisture index was developed using a linear combination of the first order polynomials. The Extended Fourier Amplitude Sensitivity Test (eFAST) was used to calculate the relative variance contribution of model input parameters to the variance of soil moisture predictions. Results derived from satellite data including Enhanced Thematic Mapper Plus (ETM +) and the Moderate Resolution Imaging Spectroradiometer (MODIS) imagery demonstrated significant correlations between the index and soil moisture obtained for different ecosystem and vegetation cover. The best agreement, the coefficient of determination (R2), between the index and soil moisture were 0.58 amd 0.65 for ETM + and MODIS data, respectively. eFAST sensitivity analysis indicates that land surface temperature might be the most determinant factor in soil moisture estimation, then albedo, followed by NDVI.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54242
Title: National Land-cover data and census of Agriculture estimates of agricutural land-use area differ in the Northeastern United States
Author: Sarah C Goslee
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: National Land-Cover Data (NLCD), Census of Agriculture (COA) , cropland, grassland
Abstract: The landscape of the northeastern United States is a complex mixture of forest, agriculture and development. Many urgent social and environmental issues require spatially-referenced information on land-use, a need potentially met by the National Land-Cover Data (NLCD). NLCD non-site-specific accuracy from 1992 and 2001 was assessed by comparing country proportions of cropland and agricultural grassland (pasture/hay) area to those recorded in the USDA Census of Agriculture (COA) for 1992 and 2002. Estimates of total agricultural area corresponded closely (r2 = 0.91 for 1992; 0.85 for 2001/2), but NLCD performed poorly at distinguishing between cropland and grassland (r2 = 0.64 adn 0.80 for cropland in 1992 and 2001; 0.50 and 0.44 for grassland in those years). High forest cover reduced accuracy. Landscape complexity and patch size may impede classification accuracy. Accuracy varied greatly by state, even within a single mapping region. The NLCD is the best available source of spatial land-cover, but may not be suitable for applications requiring agricultural subclass data.,
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54241
Title: 3D building model reconstruction from multi-view aerial imagery and Lidar Data
Author: Liang Cheng, Jianya Gong, Manchun Li and Yongxue Liu
Editor: Russell G Congalton
Year: 2011
Publisher: ASPRS, Vol 77, No 2, February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Photogrammetric Engineering & Remote Sensing
Keywords: 3D building models, multi-view aerial imagery , lidar data
Abstract: A novel approach by integrating multi-view aerial imagery and lidar data is proposed to reconstruct 3D building models with accurate geometric position and fine details. First, a new algorithm is introduced for determination of principal orientations of a building, thus benefiting to improve the correctness and robustness of boundary segment extraction in aerial imagery. A new dynamic selection strategy based on lidar point density analysis and K-means clustering is then proposed to identify boundary segments from non-boundary segments. Second, 3D boundary segments are determined by incorporating lidar data and the 2D segments extracted from multi-view imagery. Finally, a new strategy for 3D building model reconstruction including automatic recovery of lost boundaries and robust reconstruction of rooftop patches is introduced. The experimental results indicate that the proposed approach can provide high quality 3D models with high-correctness, high-completeness, and good geometric accuracy.
Location: 231
Literature cited 1: None
Literature cited 2: None
ID: 54240
Title: Recent records of the endemic Kerala mud snake, Enhydris dussumierii (Dumeril, Bibron & Dumeril, 1854) from India
Author: A Biju Kumar and Ashok Captain
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Diet, homalopsidae, Enhydris dussumierii, taxonomic characters, Vellayani Lake
Abstract: A rare, little known and endangered species of mud snake, Enhydris dussumierii (Dumeril, Bibron and Dumeril, 1854), has been reported from Vellayani Lake, Kerala, India. Some taxonomic characters are redescribed, with notes on its colour pattern, diet and occurrence.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54239
Title: New record of bumble bee, Bombus breviceps Smith as a pollinator of large cardamom
Author: T N Deka, M R Sudharshan and K A Saju
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Amomum subulatum, Bombus breviceps, heterostylic flowers, pollinator
Abstract: Large cardamom (Amomum subulatum Roxb.) belonging to the family Zingiberaceae, is the main cash crop and spice cultivated in the sub-Himalayan state of Sikkim, and Darjeeling District, West Bengal, India. It is essentially a cross-pollinated crop due to the heterostylic nature of its flowers, though they are self-fertile. Effective cross pollination occurs with the help of bumble bees due to their compatible body size within the cavity of the floral tube (corolla), bringing the upper part of the thorax in contact with the stigma and anther of the flower. The thorax carries the pollen from distant flowers. Here we report the bumble bee Bombus breviceps Smith as an effective pollinator of large cardamom during the initial flowering period at different altitudes of cultivations.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54238
Title: Hydrogen generation by gamma irradiation of aqueous turbid solution of titanium
Author: A G Kumbhar, A D Belapurkar, G Venkatewaran, S Bera, D B Naik, K Kishore, A Sanjukta and R Mythili
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: H2 generation, methanol, radiolysis, gamma - radiation dose, water
Abstract: Irradiation of titanium metal turbidity (aqueous suspension) by Co gamma-radiation generated a significant quantity of hydrogen. Titanium turbidity containing particles of micron/submicron size was generated by stirring titanium metal powder at 700C in water and was exposed to gamma-radiation dose. Yield of radiolytic hydrogen, G(H2) was estimated by gas chromatography. In the presence of Ti turbidity, 10-20 times increase in hydrogen generation was observed as compared to that in plain or pristine water. G (H2) was found to increase with concentration of Ti turbidity. Gas to liquid volume ratio (G/L) of 1.0 was found to be optimum for maximum hydrogen yield. Effect of gamma -radiation dose on total H2 yield and G (H2) was studied. Interference with hydrogen and hydroxyl radical recombination due to the reactivity of Ti3+ with hydroxyl radical seems to be the primary reason for enhanced radiolytic hydrogen production. Methanol addition to Ti turbid solution appears to increase hydrogen generation by almost 100 times. An outlay for medium scale hydrogen generation using gamma- radiation energy is also being worked out.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54237
Title: Arsenic and chromium hyperaccumulation by an ecotype of Pteris vittata- prospective for phytoextraction from contaminated water and soil
Author: Shweta Kalve, Bijaya Ketan Sarangi, Ram Awatar Pandey and Tapan Chakrabarti
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Arsenic, chromium, hyperaccumulation, Pteris vittata, remediation
Abstract: This study was carried out to identify Pteris vittata plant in India, which is reported elsewhere as an arsenic hyperaccumulator. This is the first report of characterization of arsenic (As) accumulation in an Indian ecotype, which also shows chromium (Cr) hyperaccumulation in addition to As. Intact plantlets were grown in 20% Hoagland solution amended with up to 200 mg As or Cr l-1 medium. Plants absorbed and accumulated a significant amount of As and Cr in their biomass with high bioenrichment factor. As and Cr tolerance by spores and gametophytes under in vitro was also assessed. As and Cr accumulation in the gametophyte biomass was more when spores were directly germinated on As- and Cr- supplemented media. As and Cr accumulation in the gametophyte biomass was less when spores were germinated first on media devoid of As and Cr but subsequently grown on As- and Cr- amended media.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54236
Title: To split or not to split: the case of the African elephant
Author: Nandini R Shetty and T N C Vidya
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54235
Title: Nepenthes khasiana: the pitcher plant needs attention for conservation
Author: Banani Mandal, Arunava Mukherjee
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54234
Title: Indian Bullfrog Hoplobatrachus tigerinus (Daudin, 1803) of Ousteri Lake, Puducherry
Author: R Alexandar
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 6, 25 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54233
Title: Characterization of reflectance spectra of lunar analog rocks: gabbro and norite
Author: S Arivazhagan and S Anbazhagan
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Gabbro, norite, reflectance spectra, lunar analog
Abstract: Gabbro and noritic rocks are of particular interest to lunar scientists because they stratigraphically represent the deeper zones of the lunar crust. This communication reports reflectance spectra under 350-2500 nm for lunar analog rocks like gabbro and norite and a comparison with mineralogy and chemical composition. The gabbro and norite distinctly vary in terms of albedos of reflectance spectra. However, these rocks have common absorption bands in the visible-near infrared and SWIR spectral range. Norite has pyroxene absorption at 1072 nm, whereas this absorption is absent in gabbro. Similarly, the broader absorption band at 1200 nm in gabbro is probably due to overlapping absorption by crystalline plagioclase feldspar and the presence of pyroxene. Overall, minor variation in absorption bands, percentage of albedos and band depth are the diagnostic features useful for remote mapping of similar rock types on the lunar surface.
Location: 241
Literature cited 1: None
Literature cited 2: None