bluuebunny/crossref_metadata_2025 huggingface dataset:
ADVANCING THE DOCUMENTATION OF BURIED ARCHAEOLOGICAL LANDSCAPES
Authors: Neubauer W. , Doneus M. , Trinks I.
Published: August 2012

Abstract. The future demands on professional archaeological prospection will be its ability to cover large areas in a time and cost efficient manner with very high spatial resolution and accuracy. The objective of the 2010 in Vienna established Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, in collaboration with its nine European partner organisations, is the advancement of the state-of-the-art. This goal will be achieved by focusing on the development of remote sensing, geophysical prospection and virtual reality applications. Main focus will be placed on novel integrated interpretation approaches combining cutting-edge near-surface prospection methods with advanced computer science.
RECORDING APPROACH OF HERITAGE SITES BASED ON MERGING POINT CLOUDS FROM HIGH RESOLUTION PHOTOGRAMMETRY AND TERRESTRIAL LASER SCANNING
Authors: Grussenmeyer P. , Alby E. , Landes T. , Koehl M. , Guillemin S. , Hullo J. F. , Assali P. , Smigiel E.
Published: August 2012

Abstract. Different approaches and tools are required in Cultural Heritage Documentation to deal with the complexity of monuments and sites. The documentation process has strongly changed in the last few years, always driven by technology. Accurate documentation is closely relied to advances of technology (imaging sensors, high speed scanning, automation in recording and processing data) for the purposes of conservation works, management, appraisal, assessment of the structural condition, archiving, publication and research (Patias et al., 2008). We want to focus in this paper on the recording aspects of cultural heritage documentation, especially the generation of geometric and photorealistic 3D models for accurate reconstruction and visualization purposes. The selected approaches are based on the combination of photogrammetric dense matching and Terrestrial Laser Scanning (TLS) techniques. Both techniques have pros and cons and recent advances have changed the way of the recording approach. The choice of the best workflow relies on the site configuration, the performances of the sensors, and criteria as geometry, accuracy, resolution, georeferencing, texture, and of course processing time. TLS techniques (time of flight or phase shift systems) are widely used for recording large and complex objects and sites. Point cloud generation from images by dense stereo or multi-view matching can be used as an alternative or as a complementary method to TLS. Compared to TLS, the photogrammetric solution is a low cost one, as the acquisition system is limited to a high-performance digital camera and a few accessories only. Indeed, the stereo or multi-view matching process offers a cheap, flexible and accurate solution to get 3D point clouds. Moreover, the captured images might also be used for models texturing. Several software packages are available, whether web-based, open source or commercial. The main advantage of this photogrammetric or computer vision based technology is to get at the same time a point cloud (the resolution depends on the size of the pixel on the object), and therefore an accurate meshed object with its texture. After matching and processing steps, we can use the resulting data in much the same way as a TLS point cloud, but in addition with radiometric information for textures. The discussion in this paper reviews recording and important processing steps as geo-referencing and data merging, the essential assessment of the results, and examples of deliverables from projects of the Photogrammetry and Geomatics Group (INSA Strasbourg, France).
THE HUAIHE BASIN WATER RESOURCE AND WATER QUALITY MANAGEMENT PLATFORM IMPLEMENTED WITH A SPATIO-TEMPORAL DATA MODEL
Authors: Liu Y. , Zhang W. , Yan C.
Published: August 2012

Abstract. Presently, planning and assessment in maintenance, renewal and decision-making for watershed hydrology, water resource management and water quality assessment are evolving toward complex, spatially explicit regional environmental assessments. These problems have to be addressed with object-oriented spatio-temporal data models that can restore, manage, query and visualize various historic and updated basic information concerning with watershed hydrology, water resource management and water quality as well as compute and evaluate the watershed environmental conditions so as to provide online forecasting to police-makers and relevant authorities for supporting decision-making. The extensive data requirements and the difficult task of building input parameter files, however, has long been an obstacle to use of such complex models timely and effectively by resource managers. Success depends on an integrated approach that brings together scientific, education and training advances made across many individual disciplines and modified to fit the needs of the individuals and groups who must write, implement, evaluate, and adjust their watershed management plans. The centre for Hydro-science Research, Nanjing University, in cooperation with the relevant watershed management authorities, has developed a WebGIS management platform to facilitate this complex process. Improve the management of watersheds over the Huaihe basin through the development, promotion and use of a web-based, user-friendly, geospatial watershed management data and decision support system (WMDDSS) involved many difficulties for the development of this complicated System. In terms of the spatial and temporal characteristics of historic and currently available information on meteorological, hydrological, geographical, environmental and other relevant disciplines, we designed an object-oriented spatiotemporal data model that combines spatial, attribute and temporal information to implement the management system. Using this system, we can update, query and analyze environmental information as well as manage historical data, and a visualization tool was provided to help the user interpret results so as to provide scientific support for decision-making. The utility of the system has been demonstrated its values by being used in watershed management and environmental assessments.
ASSESSMENT OF COASTAL VULNERABILITY TO SEA LEVEL RISE OF BOLINAO, PANGASINAN USING REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEMS
Authors: Reyes S. R. C. , Blanco A. C.
Published: August 2012

Abstract. A number of studies assessing the vulnerability of Southeast Asia to climate change have classified the Philippines as one of the vulnerable countries in the region. Bolinao, Pangasinan is a municipality located in northwestern Luzon, situated in the western part of the Lingayen Gulf and is bounded on the north and west by the South China Sea (West Philippine Sea). Recent studies have verified the varying trends in sea level across the South China Sea, which is considered as one of the largest, semi-enclosed marginal seas in the northwest Pacific Ocean. Three barangays (villages) were included in the study: (1) Luciente 1.0, (2) Concordia and (3) Germinal. The Socioeconomic Vulnerability Index (SVI) was computed based on population, age, gender, employment, source of income and household size, which were gathered through a qualitative survey in the selected barangays. The Coastal Vulnerability Index (CVI) described the physical vulnerability of these coastal communities based on recorded sea level anomalies and significant wave heights of multiple satellite altimetry missions, coastal topography derived from the 25-m SRTM digital elevation model (DEM), bathymetry from WorldView-2 and additional elevation data from terrestrial laser scanning surveys. The research utilized merged satellite altimetry data downloaded from the Radar Altimetry Database System (RADS), which covered the period from 1991–2010. The SVI and CVI were calculated and evaluated in ArcGIS. The SVI and CVI were integrated to determine the Total Vulnerability Index (TVI), which characterized the vulnerability of the three barangays in five classes, from very low to very high vulnerability.
LIDAR AND VHRS DATA FOR ASSESSING LIVING QUALITY IN CITIES – AN APPROACH BASED ON 3D SPATIAL INDICES
Authors: Tompalski P. , Wężyk P.
Published: August 2012

Abstract. Modern spatial data acquisition technologies like airborne laser scanning and satellite images can be used to automatically map land cover classes. The layers representing spatial extent of various terrain objects are very valuable, especially when the 3D geometrical information stored in the ALS point clouds is taken into consideration. The paper describes a research aimed to develop a way to characterize the urban areas concerning the amount of vegetation and the relation between the vegetated areas and buildings. This relation can be used to characterize the living quality. Two proposed 3D spatial indices describe the relationship between the volume of the high vegetation and volume of buildings (VV2BV) or a relationship between the volume and area of vegetated and built-up areas (UVI). These indices can be calculated for a grid of user-defined cell size or for each building separately. In the second case, a user-defined buffer zone around each building is created to specify the calculation area. The fact that the indices are based on the 3D information, introduces a new method of mapping the urban green space and is suitable for characterizing the living conditions.
AN ASSESSMENT OF SHADOW ENHANCED URBAN REMOTE SENSING IMAGERY OF A COMPLEX CITY – HONG KONG
Authors: Wan C.-Y. , King B. A. , Li Z.
Published: August 2012

Abstract. Large portions of shadowed areas in satellite images of urban areas can affect the accuracy of classification and thus reduce an image's effectiveness in urban remote sensing applications. This is particularly acute in cities such as Hong Kong where dense high-rise buildings cast many long shadows across a variety of different surface types. One solution to this problem is to enhance shadowed areas so their spectral range becomes closer to their corresponding non-shadowed areas. Shadowed areas were automatically selected and two techniques, Gamma correction and Linear Correlation Correction, were applied to three study sites of a 2.4 m Quickbird image. The selected study sites represent typical urban types of Hong Kong, ranging from high-rise commercial to low-rise residential areas. The shadow detection algorithm is based on the spectral shape index and its limitation is discussed. The histograms of the corresponding non-shadowed areas, the original and the enhanced shadow areas are used to compare the spectral range. The results show that the enhanced areas, in band ratios such as NDVI, show greater similarity after enhancement, but they also look darker than the non-shadowed areas. Where continuous shadowed areas such as in commercial areas, the spectral range cannot be restored.
AUTOMATED MULTI-SOURCE REMOTE SENSING IMAGE REGISTRATION BASED ON PHASE CONGRUENCY
Authors: Ye Y. , Xiong L. , Shan J.
Published: August 2012

Abstract. Automated registration of multi-source remote sensing data, e.g., optical, SAR, LiDAR data, could be difficult due to their heterogeneity. This paper proposes a method based on the concept of phase congruency, a measure of feature significance robust to change in illumination and contrast. We first calculate the phase congruencies respectively for the input image and the reference image to reduce local illumination and contrast difference caused by the heterogeneity or radiometric variation. Minimum moment of phase congruency is used to select feature points in the input image, followed by a normalized cross correlation to determine their correspondences in the reference image. Prior georeferencing information and image pyramid guide the above matching process, which is then refined by means of least squares matching (LSM) method. The proposed method uses random sample consensus (RANSAC) to remove the large correspondence errors caused by e.g., shadow and shielding. Finally, image registration is achieved by determining a projective transformation between the two images based on the final set of correspondences. The proposed method is evaluated with multi-source remote sensing images, including optical images, SAR images and LiDAR data. The registration quality is evaluated by using manually collected check points. The results demonstrate that the proposed method is robust and can achieve a registration accuracy which can be comparable to that produced by manual registration.
E-LEARNING – BEST PRACTICE IN PHOTOGRAMMETRY, REMOTE SENSING AND GIS – STATUS AND CHALLENGES
Authors: König G. , Shih P. T. Y. , Katterfeld C.
Published: August 2012

Abstract. In addition to professional training, computer aided teaching has long tradition. The difficult economic situation, however, forced many customers to take drastic austerity measures in the field of learning. Cost pressure encouraged a new openness to innovative and tailored learning concepts. As a result e-learning gained more interest and importance promising great benefit to the user. Around the world a variety of well-designed e-learning products exist. The web pages of Commission VI/2 (http://www.igg.tuberlin. de/ISPRS/) provide a decision aid to locate relevant material. Links to websites known to the authors are listed; a search function allows selective access, taking account of quality criteria. This article describes best practice e-learning applications in photogrammetry, remote sensing and GIS. The rating is based on results of the Computer Assisted Teaching CONtest (CATCON) initiated by ISPRS, and on observation of recent developments.
REFLECTANCE CALIBRATION SCHEME FOR AIRBORNE FRAME CAMERA IMAGES
Authors: Beisl U.
Published: August 2012

Abstract. The image quality of photogrammetric images is influenced by various effects from outside the camera. One effect is the scattered light from the atmosphere that lowers contrast in the images and creates a colour shift towards the blue. Another is the changing illumination during the day which results in changing image brightness within an image block. In addition, there is the so-called bidirectional reflectance of the ground (BRDF effects) that is giving rise to a view and sun angle dependent brightness gradient in the image itself. To correct for the first two effects an atmospheric correction with reflectance calibration is chosen. The effects have been corrected successfully for ADS linescan sensor data by using a parametrization of the atmospheric quantities. Following Kaufman et al. the actual atmospheric condition is estimated by the brightness of a dark pixel taken from the image. The BRDF effects are corrected using a semi-empirical modelling of the brightness gradient. Both methods are now extended to frame cameras. Linescan sensors have a viewing geometry that is only dependent from the cross track view zenith angle. The difference for frame cameras now is to include the extra dimension of the view azimuth into the modelling. Since both the atmospheric correction and the BRDF correction require a model inversion with the help of image data, a different image sampling strategy is necessary which includes the azimuth angle dependence. For the atmospheric correction a sixth variable is added to the existing five variables visibility, view zenith angle, sun zenith angle, ground altitude, and flight altitude – thus multiplying the number of modelling input combinations for the offline-inversion. The parametrization has to reflect the view azimuth angle dependence. The BRDF model already contains the view azimuth dependence and is combined with a new sampling strategy.
SENSITIVITY ANALYSIS IN THE RETRIEVAL OF TURBID COASTAL WATER BATHYMETRY USING WORLDVIEW-2 SATELLITE DATA
Authors: Liew S. C. , Chang C. W. , Kwoh L. K.
Published: August 2012

Abstract. The recently launched Worldview-2 satellite provides high resolution (2-m multispectral) data in eight spectral bands in the visible to near-infrared region. The additional spectral bands provide an opportunity to test several algorithms for retrieving the water depth, bottom albedo and intrinsic optical properties of coastal sea water. In a previous work (Liew et al., 2011) we reported our attempts in retrieving water depth and bottom albedo using WorldView-2 data for the purpose of coastal habitat mapping. In this paper, we investigate the sensitivity and limitations in using WorldView-2 spectral bands for bathymetry retrieval in turbid coastal waters. For typical coastal waters with a dark seabed, the most sensitive band is the Green Band which is sensitive to water depth up to about 5.3 m. For coastal waters with a bright sandy seabed, the Red and Yellow Bands are the most sensitive, but the maximum sensitive depth is reduced to about 2.4 m.
ANOMALY DETECTION AND COMPARATIVE ANALYSIS OF HYDROTHERMAL ALTERATION MATERIALS TROUGH HYPERSPECTRAL MULTISENSOR DATA IN THE TURRIALBA VOLCANO
Authors: Rejas J. G. , Martínez-Frías J. , Bonatti J. , Martínez R. , Marchamalo M.
Published: August 2012

Abstract. The aim of this work is the comparative study of the presence of hydrothermal alteration materials in the Turrialba volcano (Costa Rica) in relation with computed spectral anomalies from multitemporal and multisensor data adquired in spectral ranges of the visible (VIS), short wave infrared (SWIR) and thermal infrared (TIR). We used for this purposes hyperspectral and multispectral images from the HyMAP and MASTER airborne sensors, and ASTER and Hyperion scenes in a period between 2002 and 2010. Field radiometry was applied in order to remove the atmospheric contribution in an empirical line method. HyMAP and MASTER images were georeferenced directly thanks to positioning and orientation data that were measured at the same time in the acquisition campaign from an inertial system based on GPS/IMU. These two important steps were allowed the identification of spectral diagnostic bands of hydrothermal alteration minerals and the accuracy spatial correlation. Enviromental impact of the volcano activity has been studied through different vegetation indexes and soil patterns. Have been mapped hydrothermal materials in the crater of the volcano, in fact currently active, and their surrounding carrying out a principal components analysis differentiated for a high and low absorption bands to characterize accumulations of kaolinite, illite, alunite and kaolinite+smectite, delimitating zones with the presence of these minerals. Spectral anomalies have been calculated on a comparative study of methods pixel and subpixel focused in thermal bands fused with high-resolution images. Results are presented as an approach based on expert whose main interest lies in the automated identification of patterns of hydrothermal altered materials without prior knowledge or poor information on the area.
GEOSTATISTICAL ANALYSIS OF SURFACE TEMPERATURE AND IN-SITU SOIL MOISTURE USING LST TIME-SERIES FROM MODIS
Authors: Sohrabinia M. , Rack W. , Zawar-Reza P.
Published: August 2012

Abstract. The objective of this analysis is to provide a quantitative estimate of the fluctuations of land surface temperature (LST) with varying near surface soil moisture (SM) on different land-cover (LC) types. The study area is located in the Canterbury Plains in the South Island of New Zealand. Time series of LST from the MODerate resolution Imaging Spectro-radiometer (MODIS) have been analysed statistically to study the relationship between the surface skin temperature and near-surface SM. In-situ measurements of the skin temperature and surface SM with a quasi-experimental design over multiple LC types are used for validation. Correlations between MODIS LST and in-situ SM, as well as in-situ surface temperature and SM are calculated. The in-situ measurements and MODIS data are collected from various LC types. Pearson’s r correlation coefficient and linear regression are used to fit the MODIS LST and surface skin temperature with near-surface SM. There was no significant correlation between time-series of MODIS LST and near-surface SM from the initial analysis, however, careful analysis of the data showed significant correlation between the two parameters. Night-time series of the in-situ surface temperature and SM from a 12 hour period over Irrigated-Crop, Mixed-Grass, Forest, Barren and Open- Grass showed inverse correlations of -0.47, -0.68, -0.74, -0.88 and -0.93, respectively. These results indicated that the relationship between near-surface SM and LST in short-terms (12 to 24 hours) is strong, however, remotely sensed LST with higher temporal resolution is required to establish this relationship in such time-scales. This method can be used to study near-surface SM using more frequent LST observations from a geostationary satellite over the study area.
EVALUATION OF TERRESTRIAL LASER SCANNING FOR RICE GROWTH MONITORING
Authors: Tilly N. , Hoffmeister D. , Liang H. , Cao Q. , Liu Y. , Lenz-Wiedemann V. , Miao Y. , Bareth G.
Published: August 2012

Abstract. The rapidly growing world population and the resulting pressure on the efficiency of agriculture require a sustainable development of intensive field management with regard to natural resources. In this context, the use of non-destructive remote sensing technologies to monitor status and change detection of plant growth is in the focus of research and application. In this contribution, we evaluate the applicability of multitemporal terrestrial laser scanning (TLS) for rice growth monitoring. The test sites are located around Jiansanjiang in Heilongjiang Province in the far northeast of China. The focus of the field experiment was on different nitrogen fertilizer inputs during the growing period in 2011. To realize the monitoring approach, three campaigns were carried out during the vegetative stage of rice plants. For all campaigns the terrestrial laser scanner Riegl VZ-1000 was used. The achieved knowledge can be described in two parts. First, for each date the variability of plant height and biomass is detectable for the whole experiment field and – more important – between the plots. Furthermore, differences in height and biomass related to edge effects can be investigated for every single plot. The spatial distribution is visualized by Crop Surface Models (CSM), which are digital surface models with a high resolution and accuracy achieved by the interpolation of the 3D point clouds. Secondly, the multitemporal surveying approach enables the monitoring of the growth rate of the rice plants. Additionally, it is possible to detect and analyze as well the spatial distribution of the changes by comparing the CSMs. Our results show that TLS is a suitable and promising method for rice growth monitoring. Furthermore, the contemporaneous surveying with other sensors enables us to validate our measurements and bares opportunities for further enhancements.
ACCURACY IMPROVEMENT OF CHANGE DETECTION BASED ON COLOR ANALYSIS
Authors: Wang J. , Koizumi H. , Kamiya T.
Published: August 2012

Abstract. Change detection is one of the most important topics in the application field of aerial images and satellite images. In this paper, a novel framework for accuracy improvement on change detection is proposed. The proposed framework consists of three parts. Firstly, the location difference between the two orthoimages for change detection is rectified globally. Secondly, the illumination change of the orthoimages from two different times is adjusted to produce the orthoimages with more unified illumination condition. Thirdly, the location difference between the two orthoimages is adjusted in more precise level of local regions. Experimental results show that the detection accuracy of change detection is greatly improved through the pre-processing of the proposed framework.
INTEGRATED FUSION METHOD FOR MULTIPLE TEMPORAL-SPATIAL-SPECTRAL IMAGES
Authors: Shen H.
Published: August 2012

Abstract. Data fusion techniques have been widely researched and applied in remote sensing field. In this paper, an integrated fusion method for remotely sensed images is presented. Differently from the existed methods, the proposed method has the performance to integrate the complementary information in multiple temporal-spatial-spectral images. In order to represent and process the images in one unified framework, two general image observation models are firstly presented, and then the maximum a posteriori (MAP) framework is used to set up the fusion model. The gradient descent method is employed to solve the fused image. The efficacy of the proposed method is validated using simulated images.
SPACEBORNE SAR IMAGERY STEREO POSITIONING BASED ON RANGE-COPLANARITY EQUATION
Authors: Cheng C. Q. , Zhang J. X. , Huang G. M. , Luo C. F.
Published: August 2012

Abstract. Stereo positioning is a important content for Spaceborne SAR imagery mapping, which is still lack of investigation depend on exterior orientation elements. In this paper, we firstly introduced the Range-Coplanarity (R-Cp) geometric imaging equation and its character for radar imagery, compared the difference and relationship between R-Cp and R-D model, and build stereo positioning rigorous model for spaceborne SAR imagery based on the R-Cp equation, satellite orbit, and pose refinement model. Then separate taking TerraSAR-X images in mountainous terrain observed from same and opposite side-looking direction as test data, we presented the initial attitude value acquirement method for TerraSAR-X image after moving compensation, analyzed stereo positioning precision according to amounts and spatial distributions of GCPs and lengths of baseline between SAR antennas, and also compared the precision with R-D model. the proposed stereo positioning model avoids SAR signal imaging parameters during the geometric processing, with one GCP it could improved the plan and height precision from (17.9m,29.2m) to (10.3m,6.1m) in the test of opposite side-looking direction images, and even had a better accuracy than R-D model when more GCPs were used, which indicate that R-Cp model have a potential application in spaceborne SAR image stereo positioning.
THE PERFORMANCE ANALYSIS OF AN AKF BASED TIGHTLY-COUPLED INS/GPS INTEGRATED POSITIONING AND ORIENTATION SCHEME WITH ODOMETER AND NON-HOLONOMIC CONSTRAINTS
Authors: Peng K.-Y. , Lin C.-A. , Chiang K.-W.
Published: August 2012

Abstract. INS/GPS integration scheme can overcome the shortcoming of GPS or INS alone to provide superior performance, thus this study implements a tightly-coupled INS/GPS integration scheme using AKF as the core estimator by tuning the measurement noise matrix R adaptively. The AKF is based on the maximum likelihood criterion for choosing the most appropriate weight and thus the Kalman gain factors. The conventional EKF implementation suffers uncertain results while the update measurement noise matrix R and/or the process noise matrix Q does not meet the case. The primary advantage of AKF is that the filter has less relationship with the priori statistical information because R and/or Q vary with time. The innovation sequence is used to derive the measurement weights through the covariance matrices, innovation-based adaptive estimation (IAE) in this study. The covariance matrices R are adapted in the study when measurements update with time. A window based approach is implemented to update the quality of GPS pseudo-range measurements by adaptively replace the measurement weights through the latest estimated covariance matrices R. The use of odometer is particularly recommended when a low cost and precise vehicle localization system has to be implemented and there is the risk of GPS coverage failure, which is prone to happen when the vehicle enters a tunnel or cross deep valleys. Odometers are applied in land-vehicle navigation to provide augmented host velocity observations for standalone INS system in this study. There are two non-holonomic constraints (NHC) available for land vehicles. Land vehicles will not jump off the ground or slid on the ground under normal condition. Using these constraints, the velocity of the vehicle in the plane perpendicular to the forward direction is almost zero. EKF and AKF based tightly-coupled scheme with NHC is implemented in the study. To validate the performance of AKF based tightly-coupled INS/GPS integration scheme with odometer and NHC, field scenarios were conducted in the downtown area of Tainan city. The data fusion of INS/GPS/Odometer/NHC can be used as stand-alone positioning tool during GPS outages of over 1 minute, and AKF based tightly-coupled INS/GPS integration scheme can be more stable combined with odometer and NHC during GPS outages of over 1 minute likewise.
DIRECT GEOREFERENCING WITH ON BOARD NAVIGATION COMPONENTS OF LIGHT WEIGHT UAV PLATFORMS
Authors: Pfeifer N. , Glira P. , Briese C.
Published: August 2012

Abstract. Unmanned aerial vehicles (UAV) are a promising platform for close range airborne photogrammetry. Next to the possibility of carrying certain sensor equipment, different on board navigation components may be integrated. These devices are getting, due to recent developments in the field of electronics, smaller and smaller and are easily affordable. Therefore, UAV platforms are nowadays often equipped with several navigation devices in order to support the remote control of a UAV. Furthermore, these devices allow an automated flight mode that allows to systematically sense a certain area or object of interest. However, next to their support for the UAV navigation they allow the direct georeferencing of synchronised sensor data. This paper introduces the direct georeferencing of airborne UAV images with a low cost solution based on a quadrocopter. The system is equipped with a Global Navigation Satellite System (GNSS), an Inertial Measurement Unit (IMU), an air pressure sensor, a magnetometer, and a small compact camera. A challenge using light weight consumer-grade sensors is the acquisition of high quality images with respect to brightness and sharpness. It is demonstrated that an appropriate solution for data synchronisation and data processing allows a direct georeferencing of the acquired images with a precision below 1m in each coordinate. The precision for roll and pitch is below 1° and for the yaw it is 2.5°. The evaluation is based on image positions estimated based on the on board sensors and compared to an independent bundle block adjustment of the images.
ATMOSPHERIC LIDAR NOISE REDUCTION BASED ON ENSEMBLE EMPIRICAL MODE DECOMPOSITION
Authors: Li J. , Gong W. , Ma Y.
Published: August 2012

Abstract. As an active remote sensing instrument, lidar provides a high spatial resolution vertical profile of aerosol optical properties. But the effective range and data reliability are often limited by various noises. Performing a proper denoising method will improve the quality of the signals obtained. The denoising method based on ensemble empirical mode decomposition (EEMD) is introduced, but the denoised results are difficult to evaluated. A dual field-of-view lidar for observing atmospheric aerosols is described. The backscattering signals obtained from two channels have different signal-to-noise ratios (SNR). To overcome the drawback of the simulation experiment, the performance of noise reduction can be investigated by comparing the high SNR signal and the denoised low SNR signal. With this approach, some parameters of the denoising method based on EEMD can be determined effectively. The experimental results show that the EEMD-based method with proper parameters can effectively increase the atmospheric lidar observing ability.
SHALLOW-WATER BATHYMETRY OVER VARIABLE BOTTOM TYPES USING MULTISPECTRAL WORLDVIEW-2 IMAGE
Authors: Doxani G. , Papadopoulou M. , Lafazani P. , Pikridas C. , Tsakiri-Strati M.
Published: August 2012

Abstract. Image processing techniques that involve multispectral remotely sensed data are considered attractive for bathymetry applications as they provide a time- and cost-effective solution to water depths estimation. In this paper the potential of 8-bands image acquired by Worldview-2 satellite in providing precise depth measurements was investigated. Multispectral image information was integrated with available echo sounding and GPS data for the determination of the depth in the area of interest. In particular the main objective of this research was to evaluate the effectiveness of high spatial and spectral resolution of the new imagery data on water depth measurements using the Lyzenga linear bathymetry model. The existence of sea grass in a part of the study area influenced the linear relationship between water reflectance and depth. Therefore the bathymetric model was applied in three image parts: an area with sea grass, a mixed area and a sea grass-free area. In the last two areas the model worked successfully supported by the multiplicity of the imagery bands.
YANGON RIVER GEOMORPHOLOGY IDENTIFICATION AND ITS ENVIROMENTAL IMAPACTS ANALSYSI BY OPTICAL AND RADAR SENSING TECHNIQUES
Authors: Lwin A. , Khaing M. M.
Published: August 2012

Abstract. The Yangon river, also known as the Rangoon river, is about 40 km long (25miles), and flows from southern Myanmar as an outlet of the Irrawaddy (Ayeyarwady) river into the Ayeyarwady delta. The Yangon river drains the Pegu Mountains; both the Yangon and the Pathein rivers enter the Ayeyarwady at the delta. Fluvial geomorphology is based primarily on rivers of manageable dimensions. The emphasis is on geomorphology, sedimentology of Yangon river and techniques for their identification and management. Present techniques such as remote sensing have made it easier to investigate and interpret in details analysis of river geomorphology. In this paper, attempt has been made the complicated issues of geomorphology, sedimentation patterns and management of river system and evolution studied. The analysis was carried out for the impact of land use/ land cover (LULC) changes on stream flow patterns. The hydrologic response to intense, flood producing rainfall events bears the signatures of the geomorphic structure of the channel network and of the characteristic slope lengths defining the drainage density of the basin. The interpretation of the hydrologic response as the travel time distribution of a water particle randomly injected in a distributed manner across the landscape inspired many geomorphic insights. In 2008, Cyclone Nargis was seriously damaged to mangrove area and its biodiversity system in and around of Yangon river terraces. A combination of digital image processing techniques was employed for enhancement and classification process. It is observed from the study that middle infra red band (0.77mm – 0.86mm) is highly suitable for mapping mangroves. Two major classes of mangroves, dense and open mangroves were delineated from the digital data.
SHADOW EFFECT ON PHOTOVOLTAIC POTENTIALITY ANALYSIS USING 3D CITY MODELS
Authors: Alam N. , Coors V. , Zlatanova S. , Oosterom P. J. M.
Published: August 2012

Abstract. Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases performance of the Photovoltaic system and it always changes due to the movement of the sun. Solar radiation incident on earth's atmosphere is relatively constant but the radiation at earth's surface varies due to absorption, scattering, reflection, change in spectral content, diffuse component, water vapor, clouds and pollution etc. In this research, it is being investigated that how efficiently real-time shadow can be detected for both direct and diffuse radiation considering reflection and other factors in contrast with the existing shadow detection methods using latest technologies and what is the minimum quality of data required for this purpose. Of course, geometric details of the building geometry and surroundings directly affect the calculation of shadows. In principle, 3D city models or point clouds, which contain roof structure, vegetation, thematically differentiated surface and texture, are suitable to simulate exact real-time shadow. This research would develop an automated procedure to measure exact shadow effect from the 3D city models and a long-term simulation model to determine the produced energy from the photovoltaic system. In this paper, a developed method for detecting shadow for direct radiation has been discussed with its result using a 3D city model to perform a solar energy potentiality analysis.
REGIONALIZATION OF AGRICULTURAL MANAGEMENT BY USING THE MULTI-DATA APPROACH (MDA)
Authors: Bareth G. , Waldhoff G.
Published: August 2012

Abstract. Regional process-based (agro-)ecosystem modelling depends mainly on data availability of land use, weather, soil, and agricultural management. While land use, weather, and soil data are available from official sources or can be captured with monitoring systems, management data are usually derived from official statistics for administrative units. For numerous spatial modeling approaches, these data are not satisfying. Especially for process-based agro-ecosystem modeling on regional scales, spatially disaggregated and land use dependent information on agricultural management is a must. Information about date of sowing, dates of fertilization, dates of weeding etc. are required as input parameters by such models. These models consider nitrogen (N)- and carbon (C)-matter fluxes but essential amounts of N-/C-input and N-/C-output are determined by crop management. Therefore, in this contribution a RS- and GIS-based approach for regional generation of management data is introduced. The approach is based on the Multi-data Approach (MDA) for enhanced land use/land cover mapping. The MDA is a combined RS and GIS approach. The retrieved information from multitemporal and multisensoral remote sensing analysis is integrated into official land use data to enhance both the information level of existing land use data and the quality of the land use classification. The workflow of the MDA to generate enhanced land use and land cover data consists basically of two components: (a) the methods and data of the remote sensing analysis and (b) the methods and data of the GIS analysis. The MDA results in disaggregated land use data which can be used to link crop management information about the major crops and especially crop rotations like date of sowing, fertilization, irrigation, harvest etc. to the derived land use classes. Consequently, depending on the land use, a distinct management is given in a spatial context on regional scale. In this contribution, three case studies of different regions in Germany will be presented: (i) the dairy farm region "Württembergisches Allgäu", (ii) the arable land region "Kraichgau", and (iii) the diverse Rur-Watershed in Western Germany. For each of the study regions, a different MDA-based approach for regionalizing agricultural management is applied and will be discussed.
ESTABLISHING CROP PRODUCTIVITY USING RADARSAT-2
Authors: McNairn H. , Shang J. , Jiao X. , Deschamps B.
Published: August 2012

Abstract. Crop productivity is influenced by a number of management and environmental conditions, and variations in crop growth can occur in-season due to, for example, unfavourable meteorological conditions. Consequently information on crop growth must be temporally frequent in order to adequately characterize crop productivity. Leaf Area Index (LAI) is a key indicator of crop productivity and a number of methods have been developed to derive LAI from optical satellite data. Integration of LAI estimates from synthetic aperture radar (SAR) sensors would assist in efforts to monitor crop production through the growing season, particularly during periods of persistent cloud cover. Consequently, Agriculture and Agri-Food Canada has assessed the capability of RADARSAT-2 data to estimate LAI. The results of a sensitivity analysis revealed that several SAR polarimetric variables were strongly correlated with LAI derived from optical sensors for small grain crops. As the growing season progressed, contributions from volume scattering from the crop canopies increased. This led to the sensitivity of the intensity of linear cross-polarization backscatter, entropy and the Freeman-Durden volume scattering component, to LAI. For wheat and oats, correlations above 0.8 were reported. Following this sensitivity analysis, the Water Cloud Model (WCM) was parameterized using LAI, soil moisture and SAR data. A look up table inversion approach to estimate LAI from SAR parameters, using the WCM, was subsequently developed. This inversion approach can be used to derive LAI from sensors like RADARSAT-2 to support the monitoring of crop condition throughout the cropping season.
TEMPORAL INDICES DATA FOR SPECIFIC CROP DISCRIMINATION USING FUZZY BASED NOISE CLASSIFIER
Authors: Musande V. , Kumar A. , Kale K. , Roy P. S.
Published: August 2012

Abstract. Evaluation of fuzzy based classifier to identify and map a specific crop using multi-spectral and time series data spanning over one growing season. The temporal data is pre-processed with respect to geo-registration and five spectral indices SR (Simple Ratio), NDVI (Normalized Difference Vegetation index), TNDVI (Transformed Normalized Difference Vegetation Index), SAVI (Soil- Adjusted Vegetation Index) and TVI (Triangular Vegetation Index). The noise classifier (NC) is evaluated in sub pixel classification approach and accuracy assessment has been carried out using fuzzy error matrix (FERM). The classification results with respect to the additional indices were compared in terms of image to image maximum classification accuracy. The overall accuracy observed in dataset 2 was 96.03% for TNDVI indices, using NC. Data used for this study was AWIFS for soft classification and LISS-III data for soft testing generated from Resourcesat-1(IRS-P6) satellite. The research indicates that appropriately used indices can incorporate temporal variations while extracting specific crop of interest with soft computing techniques for images having coarser spatial and temporal resolution remote sensing data.
NDVI FROM ACTIVE OPTICAL SENSORS AS A MEASURE OF CANOPY COVER AND BIOMASS
Authors: Perry E. M. , Fitzgerald G. J. , Poole N. , Craig S. , Whitlock A.
Published: August 2012

Abstract. Commercially available proximal sensors are being used in precision agriculture to provide non-destructive, real-time spatial information on 'green biomass' that may be of interest to the remote sensing community. The sensors are described as biomass sensors, but questions remain on which canopy characteristics can be best estimated by the sensor measurements. In this study Normalized Difference Vegetation Index (NDVI) measurements from active optical sensors were examined across multiple datasets, representing different active optical sensors, different years, and different sites for wheat and barley. The NDVI values were compared with spatially and temporally coincident measurements of fractional green cover and above ground biomass, expressed as dry matter in kg ha-1. Direct comparison of NDVI measurements from the different sensors for the same plots over a range of canopy cover demonstrates differences for plot means of NDVI. Canopy fractional green cover values were well described by NDVI using a linear model. Using all of the datasets, the linear regression of fractional green cover on NDVI yielded an r2 of 0.71 and a standard error of 0.12. NDVI measured by the sensors did not explain as much of the variance in dry matter as for fractional cover. Dry matter was related to NDVI using a non-linear model. For all sensors, sites and dates with green biomass, the model was fitted with r2 value of 0.27, and standard error of 2133 kg ha-1. The relationship between NDVI and dry matter was nearly linear at levels of biomass less than 1000 kg ha-1. Results for these datasets indicate that the active optical sensors may be a useful surrogate for fractional cover, but not for above ground biomass.
CHANGE ANALYSIS OF THE SPECTRAL CHARACTERISTICS OF RUBBER TREES AT CANOPY AND LEAF SCALES DURING THE BRAZILIAN AUTUMN
Authors: Amaral C. H. , Almeida T. I. R. , Quitério G. C. M. , Alves M. N. , Souza Filho C. R.
Published: August 2012

Abstract. The objective of this work is to investigate the hyperspectral remote sensing potential to detect spectral changes undergone by clones of two rubber trees within Brazilian Autumn, with decrease of rain, temperature and photoperiod between May and June. Indirectly, we also analyze the ability of the data to help discriminating the clones at two dates in autumn. The average canopy spectra of the stands were obtained with two overpasses of the ProSpecTIR-VS airborne hyperspectral sensor (357 bands between 400–2,500 nm; spatial resolution of 1m) by 14th May and 17th June, in 2010 year. Additionally measurements of leaf spectra were taken in the same dates, but in the 2011 year. Considering the analysis of the spectra measured from the three stands, this indicates that spectral differences in the VIS (400–700 nm) region are of genetic origin and occur regardless of environmental conditions and period of data collection. In the NIR (700–1,300 nm) range, the environmental factors predominate in the two periods of data collection. The SWIR (1,300–2,500 nm) displayed the largest differences between the months of data collection. In May, the relationship between stands indicated the prevalence of environmental aspects. However, in June, the stands and clones spectral behaviour indicates that as the temperature, the rainfall and the photoperiod are lower closer to winter, the SWIR can be effectively used to discriminate and map these clones separately.
BUSHFIRES IN THE KRACHI DISTRICT: THE SOCIO-ECONOMIC AND ENVIRONMENTAL IMPLICATIONS
Authors: Kusimi J. M. , Appati J. W.
Published: August 2012

Abstract. Bushfires are becoming one of the environmental challenges confronting Ghana and increasingly it has become difficult for the Government to control it because this activity is deeply rooted in the socio-cultural and economic systems of the people. The effects of bushfire on rural livelihoods and on the ecosystem in Ghana are extensive and damaging. Bushfires have accelerated environmental degradation especially in the fragile savannah ecosystem, yet there is very little in the form of public education, published data and information concerning the frequency, intensity, duration and effects of bushfire on the environment and human welfare in Ghana. The study did a change detection of biomass cover using pre and post fire normalized burnt ratio of Landsat TM+ imageries of 2002 and 2003 to determine fire severity on vegetative cover. The socio-economic impact of this disaster was collected using social survey approaches such as interviews and focus group meetings. Some of the consequences of the bushfire include the burning of food stuffs, houses as well as domestic animals. The environmental impacts of these bushfires have been very devastating and these involve the lost of biodiversity (plants and animals) and the depletion of organic matter of the soil thus impoverishing the soils. The research found out that, the continuous prevalence of this activity was due to the laxity in the implementation of bye-laws regulating bushfire burning due to the lack of personnel and logistics to state agencies in the District to combat the problem.