Proceedings Volume 7110

Remote Sensing for Environmental Monitoring, GIS Applications, and Geology VIII

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Proceedings Volume 7110

Remote Sensing for Environmental Monitoring, GIS Applications, and Geology VIII

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Volume Details

Date Published: 1 October 2008
Contents: 15 Sessions, 54 Papers, 0 Presentations
Conference: SPIE Remote Sensing 2008
Volume Number: 7110

Table of Contents

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Table of Contents

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  • Front Matter: Volume 7110
  • Remote Sensing for Archaeology, Cultural, and Natural Heritage: Geospatial Infrastructure I
  • Remote Sensing for Archaeology, Cultural, and Natural Heritage: Geospatial Infrastructure II
  • Coastal Remote Sensing
  • Urban Remote Sensing I
  • Urban Remote Sensing II
  • Remote Sensing of Hazards
  • Environmental Monitoring: Pollution
  • Data Fusion
  • Land Use and Land Cover
  • Geological Remote Sensing I
  • Geological Remote Sensing II
  • Remote Sensing Modeling
  • Novel Remote Sensing/GIS Applications
  • Poster Session
Front Matter: Volume 7110
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Front Matter: Volume 7110
This PDF file contains the front matter associated with SPIE Proceedings Volume 7110, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
Remote Sensing for Archaeology, Cultural, and Natural Heritage: Geospatial Infrastructure I
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Old high resolution satellite images for landscape archaeology: case studies from Turkey and Iraq
The paper concerns the contribution for Landscape Archaeology from satellite images of 1960s and 1970s, very useful when old aerial photographs are scarce. Particularly, the study concerns the panchromatic photos taken by USA reconnaissance satellites from 1963 to 1972, declassified for civil use in 1995 and 2002, that in the last years are very used in the archaeological research; in fact, a lot of these images have an high geometric resolution, about between 2.74 and 1.83 m (Corona KH-4A and KH-4B), and some have a ground resolution about between 1.20 and 0.60 m (Gambit KH-7). These satellite images allow to examine very in detail ancient urban areas and territories that later are changed or partially destroyed; so, it is possible to detect and examine ancient structures, palaeo-environmental elements and archaeological traces of buried features now not visible. The paper presents some exemplificative cases study in Turkey and Iraq, in which the analysis of these images has made a fundamental contribution to the archaeological researches: particularly, for the reconstruction of the urban layout of the ancient city of Hierapolis of Phrygia and for the surveys in its territory, and for the study of the ancient topography of some archaeological sites of Iraq. In this second case, the research is gained in the context of the Iraq Virtual Museum Project; the comparison with recent high resolution satellite images (Ikonos-2, QuickBird-2, WorldView-1) also provide a fundamental tool for monitoring archaeological areas and for an evaluation of the situation after the first and the second Gulf War.
The biodiversity management of a marine protected area with a geographic information system in China
Huaguo Zhang, Weigen Huang, Dongling li
This paper focus a very representatively marine protected area (MPA), named Nanji Islands National Natural Reserve. The MPA is built for protecting shellfish, algae and their inhabit environment. The MPA is located at East China Sea with 7.6 square kilometers land area, composed of about 50 islands greater than 500 square meters. The waters support particularly high levels of diversity among shellfish, seaweeds, or macro benthic algae and micro-algae. The purpose of the paper is to develop a GIS to manage the biodiversity and to assess the threat. Base geographic data are collected. More than four times survey data are collected since 1992, including shellfish and macro benthic algae. A spatial database is created to store spatial data including base map, survey site and threat factor distribution. Other biodiversity attribute information is stored in database. Aquiculture, tourism, and human over collection are synthesized as threat factors. The condition of biodiversity and threats to biodiversity at Aquaculture, tourism, environment pollution are analyzed and assessed.
Remote Sensing for Archaeology, Cultural, and Natural Heritage: Geospatial Infrastructure II
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Historical and modern aerial photography for cultural heritage and environmental knowledge
The study presented for the session "Remote sensing for archaeology, cultural, natural heritage and Geospatial Infrastructure" concern a large part of the territory between L'Aquila and Capestrano, in Abruzzo (central Italy, close to Gran Sasso Mountain). It has been interested a territory strip including the initial well known route of Tratturo Regio, an ancient pastoral passage of transhumance from high rough grazing of Abruzzo to the largest plains of northern Puglia (Tavoliere). This area has a particularly well preserved environment, very rich in archaeological remains for any chronological period. The study has been realized by direct survey, going through documents in different archives, examination of historical and modern aerial photograph. The outcome of research is a view of ancient occupation of the area, from prehistorical to medieval period. Through the analisys (or reading) of historical and present photos have been identified and localized (geographical positioning) a large amount of cropmarks concerning new sites at most (settlements, necropolis, roads, single structures, etc.).
Coastal Remote Sensing
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Multitemporal spectroradiometry-guided object-oriented classification of salt marsh vegetation
Daniel L. Civco, Martha S. Gilmore, Emily H. Wilson, et al.
This study addresses the use of multitemporal field spectral data, satellite imagery, and LiDAR top of canopy data to classify and map common salt marsh plant communities. Visible to near-infrared (VNIR) reflectance spectra were measured in the field to assess the phenological variability of the dominant species - Spartina patens, Phragmites australis and Typha spp. The field spectra and single date LiDAR canopy height data were used to define an objectoriented classification methodology for the plant communities in multitemporal QuickBird imagery. The classification was validated using an extensive field inventory of marsh species. Overall classification accuracies were 97% for Phragmites, 63% for Typha spp. and 80% for S. patens meadows. Using a fuzzy assessment analysis, these accuracies were 97%, 76%, and 92%, respectively, for the three major species.
Monitoring the invasion of Phragmites australis in coastal marshes of Louisiana, USA, using multisource remote sensing data
Pablo H. Rosso, James T. Cronin, Richard D. Stevens
Phragmites australis a native marshland species to the North American Atlantic Coast is presently expanding to new habitats at very high rates. To understand the causes and consequences of this invasion, monitoring programs, especially at the Gulf Coast, need to be established. The first step to this is to obtain a method for accurate mapping Phragmites distribution. In this study an object oriented classification approach that combines lidar and multispectral imagery is proposed. After segmentation of a dataset of three multispectral bands plus a lidar based digital surface model, two classification methods were explored: a class assignment (CA) and a nearest neighbor classification (NNC). CA requires more involvement and knowledge form the analyst, but the decisions to be made are better understood than in the NNC. Both methods performed similarly, and were able to map most of the Phragmites present in the study area. Results show that the use of multi-source data not only can produce accurate distribution maps for future monitoring, but also guide on present day surveys and even help in the interpretation of old data to map past conditions.
Application of remote sensing in coastal change detection after the tsunami event in Indonesia
H. S. Lim, M. Z. MatJafri, K. Abdullah, et al.
Shoreline mapping and shoreline change detection are critical in many coastal zone applications. This study focuses on applying remote sensing technology to identify and assess coastal changes in the Banda Aceh, Indonesia. Major changes to land cover were found along the coastal line. Using remote sensing data to detect coastal line change requires high spatial resolution data. In this study, two high spatial data with 30 meter resolution of Landsat TM images captured before and after the Tsunami event were acquired for this purpose. The two satellite images was overlain and compared with pre-Tsunami imagery and with after Tsunami. The two Landsat TM images also were used to generate land cover classification maps for the 24 December 2004 and 27 March 2005, before and after the Tsunami event respectively. The standard supervised classifier was performed to the satellite images such as the Maximum Likelihood, Minimum Distance-to-mean and Parallelepiped. High overall accuracy (>80%) and Kappa coefficient (>0.80) was achieved by the Maximum Likelihood classifier in this study. Estimation of the damage areas between the two dated was estimated from the different between the two classified land cover maps. Visible damage could be seen in either before and after image pair. The visible damage land areas were determined and draw out using the polygon tool included in the PCI Geomatica image processing software. The final set of polygons containing the major changes in the coastal line. An overview of the coastal line changes using Landsat TM images is also presented in this study. This study provided useful information that helps local decision makers make better plan and land management choices.
Urban Remote Sensing I
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Urban structure analysis of mega city Mexico City using multisensoral remote sensing data
H. Taubenböck, T. Esch, M. Wurm, et al.
Mega city Mexico City is ranked the third largest urban agglomeration to date around the globe. The large extension as well as dynamic urban transformation and sprawl processes lead to a lack of up-to-date and area-wide data and information to measure, monitor, and understand the urban situation. This paper focuses on the capabilities of multisensoral remotely sensed data to provide a broad range of products derived from one scientific field - remote sensing - to support urban managing and planning. Therefore optical data sets from the Landsat and Quickbird sensors as well as radar data from the Shuttle Radar Topography Mission (SRTM) and the TerraSAR-X sensor are utilised. Using the multi-sensoral data sets the analysis are scale-dependent. On the one hand change detection on city level utilising the derived urban footprints enables to monitor and to assess spatiotemporal urban transformation, areal dimension of urban sprawl, its direction, and the built-up density distribution over time. On the other hand, structural characteristics of an urban landscape - the alignment and types of buildings, streets and open spaces - provide insight in the very detailed physical pattern of urban morphology on higher scale. The results show high accuracies of the derived multi-scale products. The multi-scale analysis allows quantifying urban processes and thus leading to an assessment and interpretation of urban trends.
Building height retrieval from airborne VHR SAR imagery based on an iterative simulation and matching procedure
The new spaceborne very high resolution (VHR) synthetic aperture radar (SAR) sensors onboard the TerraSARX and COSMO-SkyMED satellites have a spatial resolution of up to 1 meter. In VHR SAR data, features from individual urban structures (like buildings) can be identified in their characteristic settings in urban settlement patterns. In this paper, we present a novel methodology for the height estimation for generic man made structures from single power SAR data. The proposed approach is based on the definition of a hypothesis on the height of the building and on the simulation of a SAR image for testing that hypothesis. Then a matching procedure is applied between the estimated and the actual SAR images in order to validate the height assumption. The process is iterated for different initial height assumptions until the matching function is satisfied and thus the building height is estimated. The efficiency and the properties of the proposed method are demonstrated for the height estimation of a set of 38 flat- and gable roof buildings using a VHR airborne SAR scene for a residential area in Dorsten, Germany.
Urban Remote Sensing II
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Reconstruction of residential buildings by detail analysis of multi-aspect InSAR data
State-of-the-art SAR sensors suggest utilizing InSAR-Data for the analysis of dense urban areas. The appearance of buildings in SAR or InSAR data is characterized by the effects of the inherent oblique scene illumination, such as layover, occlusion by radar shadow and multipath signal propagation. Therefore, especially in dense built-up areas reconstruction quality can be improved by a combined analysis of multi-aspect data. The presented approach focuses on reconstruction of buildings in residential districts supported by knowledge based analysis considering the mentioned SAR-specific effects. The algorithm of building extraction starts with the segmentation of primitives, such as lines and edges, followed by the assembly of building hypotheses based on typical building features like linearity and right-angularity. The subsequent post-processing of building hypotheses contains the analysis of InSAR phases to improve footprint or to detect roof-type of buildings. The results are presented by using optical data and a high resolution LIDAR surface model as ground truth data.
Feature extraction of bridges for change detection in high resolution SAR data
Erich Cadario, Hermann Gross, Horst Hammer, et al.
SAR is a remote sensing technique capable to deliver actual data at any time and under bad weather conditions. Before launch of TerraSAR-X, RADARSAT-2, or COSMO-SkyMed, the rather coarse resolution of operational SAR satellite systems allowed an analysis of spaceborne SAR data in case of disaster management only for medium scale products. The new generation of spaceborne SAR satellites permits a more detailed analysis at the object level even for urban areas, which was before restricted to airborne SAR sensors. Change detection in SAR images is an important field of research. In general, the appearance of objects in SAR images strongly depends on the viewing angle and look direction. This makes a comparison of images on a pixel level difficult. The changeover from pixel- to object level leads to the possibility, to look for object-features that are more stable concerning different imaging constellations. Bridges are keyelements of man made infrastructure. In this paper the appearance of bridges in SAR data is analyzed and features are derived that are exploitable for change detection. Here the focus is on analysis at the object level to derive features that are either stable concerning the imaging constellations or that can be predicted based on a given imaging constellation. Thereby, the usage of different sensors will be possible to achieve the goal of real time information. The investigations are supported by simulations, which allow the creation of SAR images for different imaging constellations, bridge materials, and even for situations with destroyed bridges.
An approach to enhanced fidelity of airborne radar site-specific simulation
Geographical information systems (GIS) have been the base for radar ground echo simulations for many years. Along with digital elevation model (DEM), present GIS contain characteristics of terrain. This paper proposes a computationally sensible simulation procedure to produce realistic radar terrain signatures in a form of raw data of airborne pulse Doppler radar. For backscattering simulation, the model of the ground is based on DEM and built with point-form backscattering objects. In addition to the usual DEM utilization for xyz coordinates and shadowed region calculation, we assume that each data point in GIS describes several scatterers in reality. Approaching the ground truth, we distribute individual scatterers with adjustable attributes to produce authentic response of areas such as sea, fields, forests, and built-up areas. This paper illustrates the approach through an airborne side-looking synthetic aperture radar (SAR) simulation. The results prove the enhanced fidelity with realistic SAR image features.
Urban land use/land cover mapping with high-resolution SAR imagery by integrating support vector machines into object-based analysis
This paper investigates the capability of high-resolution SAR data for urban landuse/land-cover mapping by integrating support vector machines (SVMs) into object-based analysis. Five-date RADARSAT fine-beam C-HH SAR images with a pixel spacing of 6.25 meter were acquired over the rural-urban fringe of the Great Toronto Area (GTA) during May to August in 2002. First, the SAR images were segmented using multi-resolution segmentation algorithm and two segmentation levels were created. Next, a range of spectral, shape and texture features were selected and calculated for all image objects on both levels. The objects on the lower level then inherited features of their super objects. In this way, the objects on the lower level received detailed descriptions about their neighbours and contexts. Finally, SVM classifiers were used to classify the image objects on the lower level based on the selected features. For training the SVM, sample image objects on the lower level were used. One-against-one approach was chosen to apply SVM to multiclass classification of SAR images in this research. The results show that the proposed method can achieve a high accuracy for the classification of high-resolution SAR images over urban areas.
Remote Sensing of Hazards
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Integrated geospatial system for seismic hazard assessment in Vrancea area, Romania
Geospatial information forms the basis for comprehensive seismic risk assessments and better-informed mitigation planning, disaster assessment and response prioritization. Mainly due to the subcrustal earthquakes located at the sharp bend of the Southeast Carpathians, Vrancea zone in Romania is considered one of the most seismically active area in Europe, having a relatively high potential of seismic hazard, being placed at conjunction of four tectonic blocks which lie on the edge of the Eurasian plate. Integrated in situ monitoring seismological, geologic, geophysics, satellite (IKONOS; LANDSAT TM and ETM, SAR-ERS 1/2, ASTER) and GPS data provide a better monitoring of different geophysical-geochemical parameters and long-term deformation in relation with earthquake activity.Multispectral and multitemporal satellite images over a period 1975-2007 have been analyzed for recognizing the continuity and regional relationships of active faults as well as for geologic and seismic hazard mapping. GPS Romanian network stations data revealed a displacement of about 5 or 6 millimeters per year in horizontal direction relative motion, and a few millimeters per year in vertical direction. As Vrancea area has a significant regional tectonic activity, the joint analysis of geospatial and in-situ geophysical information is revealing new insights in the field of hazard assessment.
Integrated remotely sensed datasets for disaster management
Timothy McCarthy, Ronan Farrell, Andrew Curtis, et al.
Video imagery can be acquired from aerial, terrestrial and marine based platforms and has been exploited for a range of remote sensing applications over the past two decades. Examples include coastal surveys using aerial video, routecorridor infrastructures surveys using vehicle mounted video cameras, aerial surveys over forestry and agriculture, underwater habitat mapping and disaster management. Many of these video systems are based on interlaced, television standards such as North America's NTSC and European SECAM and PAL television systems that are then recorded using various video formats. This technology has recently being employed as a front-line, remote sensing technology for damage assessment post-disaster. This paper traces the development of spatial video as a remote sensing tool from the early 1980s to the present day. The background to a new spatial-video research initiative based at National University of Ireland, Maynooth, (NUIM) is described. New improvements are proposed and include; low-cost encoders, easy to use software decoders, timing issues and interoperability. These developments will enable specialists and non-specialists collect, process and integrate these datasets within minimal support. This integrated approach will enable decision makers to access relevant remotely sensed datasets quickly and so, carry out rapid damage assessment during and post-disaster.
Integration of remote sensing with GIS for grassland snow cover monitoring and snow disaster evaluating in Tibet
Maofang Gao, Sanchao Liu, Zhihao Qin, et al.
As an important pasture region, Tibet has about 82 million hectares of natural grassland, accounting for 68.11% of its total territory. Above 90% of Tibetan grassland belongs to the types of alpine meadow steppe and alpine steppe with highly nutritious forage plant. Animal husbandry constitutes a major part of agricultural economy in Tibet. It is believed that snow disaster become a significant threat to the development of animal husbandry in Tibet. The disaster often happens in winter and spring as a result of complicated mountainous features and mutable climatic conditions. Statistics indicates that, on average, there is a slight snow disaster for each 3-year, a medium disaster within 5 to 6 years, and a big disaster in 8-10 years. Large numbers of animals died of hungry and cold during the disaster period. Huge economic loss due to the disaster had brought giant difficulties to local herdsmen in Tibet. Accurate and timely monitoring of snow cover for snow disaster evaluating is very important to provide the required information for decision-making in anti-disaster campaigns. Remote sensing has many advantages in snow disaster monitoring hence been extensively applied as the main approach for snow cover monitoring. In this paper we present our study of snow cover monitoring and snow disaster evaluating in Tibet. An applicable approach has been developed in the study for the monitoring and evaluating. The approach is based on the normalize difference of snow index (NDSI) and DEM retrieved from MODIS and GIS data. Using the approach, we analyzed the snowstorm occurring in mid-March 2007 in southern Tibet. Results from our analysis indicated that the new approach is able to provide an accurate estimate of snow cover area and snow depth in southern Tibet. Thus we may conclude that the approach can be used as an efficient alternative for snow cover monitoring and snow disaster evaluating in Tibet.
Environmental Monitoring: Pollution
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The application of hyperspectral image techniques on MODIS data for the detection of oil spills in the RSA
Fahad Alawadi, Carl Amos, Valborg Byfield, et al.
Oil spills pose a serious threat to the sensitive marine ecosystem of the RSA. The study aims to detect and identify oil spills using remote sensing data provided by ROPME MODIS receiving station. MODIS data of confirmed incidents of oil spills via in-situ observations were processed to produce radiometrically corrected L1B data. Algal mats were further eliminated as look-alike, when the distinct oil pattern was not visible in the standard MODIS algorithm for Chlorophyll a. Shape analysis based on the operators' prior knowledge of the region was also used as a method for discriminating oil from other look-alikes. Oil spills exhibit different levels of contrast in relation to the viewing angle geometry and sun position. The Spectral Contrast Shift (SCS) is an empirical relationship that was derived to identify sea surface patterns including oil spills using the maximum and minimum spectral radiance values at the 250m spatial resolution bands. Results were combined with GIS based information of oil platform locations and daily tanker routes to aid interpretation and improve the probability for an accurate identification of oil spills, and avoiding false positives.
Geospatial modelling of metocean and environmental ancillary data for the oil spill probability assessment in SAR images
Oliver Müllenhoff, Barbara Bulgarelli, Guido Ferraro, et al.
The confidence level of oil spill detections in satellite Synthetic Aperture Radar (SAR) imagery requires the analysis of many different factors. Unfortunately, oil slicks are not the only phenomena which can appear as a dark feature in a SAR image. These include a number of parameters like wind speed, currents, internal waves, upwelling sea areas, algae bloom, mixing water areas, et cetera. These phenomena are called look-alikes. The largest challenge in detecting oil spills in SAR images remains in the accurate discrimination between oil spills and look-alikes. This study introduces the vantages of using geospatial analysis of various metocean data (e.g. wind speed and direction, sea surface temperature, wave direction, ocean colour data) and environmental ancillary data (e.g. vessel traffic, port locations) as a supplementary information source for the oil spill probability assessment in SAR imagery. The analysed data exists in different formats with different value scales. In addition, the parameters of the metocean data analysis are not equally important for a reliability of oil spill detection. The weight of metocean parameters depends on the impact of natural phenomena on SAR systems (e.g. wind and currents have pro rata more influence on the probability than sea surface temperature and chlorophyll-a) and the area of interest (e.g. chlorophyll-a is a more important value for the Baltic Sea than for the Mediterranean Sea). The derived oil spill probability categorisation based on the weighted analysis of metocean environmental ancillary data could be a useful tool for authorities for an efficient planning of cost-intensive verification flights.
Numerical simulation of the pollutant transportation in Chinese Hangzhou Bay with QSCAT/NCEP wind data
Hangzhou Bay in China is an important conveyor transporting contaminants from surrounding cities in Yangtze Delta. A numerical hydrodynamic model based on COHERENS (Coupled Hydrodynamical Ecological model for Regional Shelf seas) has been employed to simulate the pollutant transport trajectory and to obtain the retention ratio in the Bay. The forcing of the model include tides and freshwater. The influence of wind was explored by imposing the QSCAT/NCEP Blend Wind data into the numerical simulation. The bay was divided into 8 subdomains (S1-S8) and the simulation was performed in two months: March (the dry season) and July (the wet season). Two sets of numerical experiment were carried out with or without wind. Results indicated that wind plays a more important role on pollutant transport in the wet season than in the dry season. The influences of wind on the pollutant transport in 8 subdomians are different, especially in wet season. The retention ratio of S1 is most significantly affected by wind compared with other subdomains.
Data Fusion
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Quality assessment for multitemporal and multisensor image fusion
Manfred Ehlers, Sascha Klonus
Generally, image fusion methods are classified into three levels: pixel level (iconic), feature level (symbolic) and knowledge or decision level. In this paper we focus on iconic techniques for image fusion. There exist a number of established fusion techniques that can be used to merge high spatial resolution panchromatic and lower spatial resolution multispectral images that are simultaneously recorded by one sensor. This is done to create high resolution multispectral image datasets (pansharpening). In most cases, these techniques provide very good results, i.e. they retain the high spatial resolution of the panchromatic image and the spectral information from the multispectral image. These techniques, when applied to multitemporal and/or multisensoral image data, still create spatially enhanced datasets but usually at the expense of the spectral consistency. In this study, a series of nine multitemporal multispectral remote sensing images (seven SPOT scenes and one FORMOSAT scene) is fused with one panchromatic Ikonos image. A number of techniques are employed to analyze the quality of the fusion process. The images are visually and quantitatively evaluated for spectral characteristics preservation and for spatial resolution improvement. Overall, the Ehlers fusion which was developed for spectral characteristics preservation for multi-date and multi-sensor fusion showed the best results. It could not only be proven that the Ehlers fusion is superior to all other tested algorithms but also the only one that guarantees an excellent color preservation for all dates and sensors.
Multidirectional decomposition and directional contrast based remote sensing images fusion
Yan Na, Manfred Ehlers, Jie Meng, et al.
Multi-directional decomposition and directional contrast based remote sensing images fusion algorithm is presented in this paper. Based on the properties of band contrast processing and contrast orientation of visual receptive fields, multi-directional contrast is introduced. The fusion procedure is as follows: first, Nonsubsampled Contourlet Transform of Panchromatic and multi-spectral images, second, construction of directional contrast sequences at different decomposition levels and different directions, third, construction of fused Nonsubsampled Contourlet Transform coefficients with multi-directional contrast fusion rule. Finally, a fused high spatial resolution multi-spectral image can be obtained with inverse Nonsubsampled Contourlet Transform. Experiment results show that multi-directional decomposition and directional contrast based remote sensing images fusion method can provide a very good fusion image. This method is better than ordinary wavelet transform based directional contrast fusion method. The fused multi-spectral image can provides more spatial information and preserve more spectral information.
Land Use and Land Cover
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Finnish CORINE 2006 project: determining changes in land cover in Finland between 2000 and 2006
Markus Haakana, Suvi Hatunen, Pekka Härmä, et al.
The European Comission introduced the CORINE Programme in 1985 in order to gather information relating to the environment for the European Union. CORINE land cover classification is produced using satellite images and visual interpretation. In Finland, CORINE has been made differently in order to produce more detailed national land cover information at the same time. Finnish CORINE 2000 was based on automated interpretation of satellite images and data integration with existing digital map data. Same process will be repeated with CORINE 2006 as well as possible. The outputs are IMAGE2006 satellite images and mosaics, CORINE 2006 land cover classification and changes 2000-2006. These will be produced in different spatial resolutions: national raster data with spatial resolution of satellite images and European LC and LC changes with MMU of 25 and 5 hectares produced using mainly automated generalization procedures.
Classification of natural areas in northern Finland using remote sensing images and ancillary data
Suvi Hatunen, Pekka Härmä, Minna Kallio, et al.
SYKE is performing new CORINE 2006-classification for Finland. One of the aims is to make CORINE classification in Northern Finland, meaning that classes like Natural grasslands and Moors and heathlands should be classified with higher accuracy. Also, some specific classes need to be interpreted for national purposes like mountain birch forests. This paper documents the first experiments made using decision tree classifier, optical and microwave remote sensing data as well as DEM and soil information. Classes are pine, spruce, deciduous tree forests, two classes of mountain birch, open bog, grasslands, heathlands and open rocks. The best overall accuracies were about 73%, when the overall accuracy of Maximum Likelihood Classification was about 58%.
Knowledge-based land use mapping integrated GIS and time-series MODIS NDVI data in Lhasa River basin, Tibet
Shengwei Zhang, Yuping Lei, Li Zheng, et al.
Tibet Plateau plays an important role in global changing and ecosystem studies because of its unique geographical location and topography. Lhasa river basin which locates in the center of Tibet Plateau is a typical and important region for agriculture and stockbreeding in Tibet. In this study a method of land cover mapping from 250m MODIS (Moderate Resolution Imaging Spectroradiometer) product Normalized Difference Vegetation Index (NDVI) MOD13Q1 data is presented. This knowledge-based method combines phenophase character of plants with time-series remote sensing data and Geographic Information System spatial analysis. A quality assessment analysis is performed to time-series data by temporal and spatial interpolation of invalid and missing data. The NDVI value is converted into a relative NVDI to avoid the misclassification arising by data change of spatial and temporal. The preliminary results are compared with both field observation points and classification mapped from Landsat TM imagery. The comparison indicates the result of classification is promising.
Geological Remote Sensing I
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EO-1 Hyperion and ALI bands simulation to Landat 7 ETM+ bands for mineral mapping in Milos Island
During the last two decades, airborne hyperspectral sensors such as the AVIRIS or DAIS have been proved very useful but quite expensive tool for the detection and mapping of earth surface minerals. On November 2000 the launch of the Earth Observing 1 (EO-1) satellite, which included Hyperion, the first spaceborne imaging spectrometer, provided a new low cost tool in remote sensing research. This study evaluates hyperspectral data from Hyperion, as well as multispectral data from the EO-1 Advanced Land Imager (ALI) and the Landsat 7 ETM+ for mineral mapping in Milos Island. The three sensors examined in this study have similar spatial resolution, totally different spectral resolution and radiometric quality characteristics. All the data were collected the same day within one-minute time. As a result the atmospheric conditions were exactly the same and that make the data ideal for comparison. The performance of the EO-1 Hyperion imaging spectrometer with the Advanced Land Imager (ALI) and the Landsat 7 ETM+ sensor was compared using a method that aggregated portions of the Hyperion 10 nm bands to simulate the broader multispectral bands of ALI and ETM+. The general process was to calculate a weighted sum of the Hyperion bands that covered each Landsat band. The weights used in the sum were derived, by comparing the spectral response of the hyperspectral bands with the respective multispectral band. Different band ratios like the TM3/TM1 sensitive on the iron oxide detection, or different combinations sensitive on mineral (TM5/7, TM5/4, TM3/1) or hydrothermal anomalies (TM5/7, TM3/1, TM4/3) detection were used for the comparison of the three data sets and the results are presented in this study.
Tunable mechanical monolithic sensor with interferometric readout for low frequency seismic noise measurement
F. Acernese, R. De Rosa, G. Giordano, et al.
This paper describes a mechanical horizontal monolithic sensor for geophysical applications developed at the University of Salerno. The instrument is basically a monolithic tunable folded pendulum, shaped with precision machining and electric-discharge-machining, that can be used both as seismometer and, in a force-feedback configuration, as accelerometer. It is a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises, whose main characteristics are the tunability of the resonance frequency and the integrated laser optical readout, consisting of an optical lever and an interferometer. The theoretical sensitivity curves are in a very good agreement with the measurements. A direct comparison of its performances with the STS-2 ones shows that better performances have been reached with the interferometric readout (≈10-12 m/square root Hz in the band 10-1 ÷10Hz as seismometer. The first results as accelerometer (force feed-back configuration) are also presented and discussed.
Spatial database for the management of "urban geology" geothematic information: the case of Drama City, Greece
Eustathios Pantelias, Alexandra D. Zervakou, Panagiotis I. Tsombos, et al.
The aggregation of population in big cities leads to the concentration of human activities, economic wealth, over consumption of natural resources and urban growth without planning and sustainable management. As a result, urban societies are exposed to various dangers and threats with economical, social, ecological - environmental impacts on the urban surroundings. Problems associated with urban development are related to their geological conditions and those of their surroundings, e.g. flooding, land subsidence, groundwater pollution, soil contamination, earthquakes, landslides, etc. For these reasons, no sustainable urban planning can be done without geological information support. The first systematic recording, codification and documentation of "urban geology" geothematic information in Greece is implemented by the Institute of Geological and Mineral Exploration (I.G.M.E.) in the frame of project "Collection, codification and documentation of geothematic information for urban and suburban areas in Greece - pilot applications". Through the implementation of this project, all geothematic information derived from geological mapping, geotechnical - geochemical - geophysical research and measurements in four pilot areas of Greece Drama (North Greece), Nafplio & Sparti (Peloponnesus) and Thrakomakedones (Attica) is stored and processed in specially designed geodatabases in GIS environment containing vector and raster data. For the specific GIS application ArcGIS Personal Geodatabase is used. Data is classified in geothematic layers, grouped in geothematic datasets (e.g. Topography, Geology - Tectonics, Submarine Geology, Technical Geology, Hydrogeology, Soils, Radioactive elements, etc) and being processed in order to produced multifunctional geothematic maps. All compiled data constitute the essential base for land use planning and environmental protection in specific urban areas. With the termination of the project the produced geodatabase and other digital data (thematic maps, DEMs) will be available to all, public or private sector, concerning geological environment in urban and suburban areas, being in charge of protection and improvement of natural and human made environment.
Geological Remote Sensing II
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Toward new methodology for improvement of topographic and anisotropic correction of desert bare soil
Ali I. Alomran, M. J. McCullagh
Desert bare soil has been found in literature to exhibit anisotropic reflectance behaviour. Anisotropy is described by Bidirectional Reflectance Distribution function (BRDF). Literature studies have limited their investigations to the behaviour of the topographic corrections of Minnaert and C models (simple forms of the empirical type of BRDF) with terrain variables (slope and orientation). Yet, none of these studies, especially for desert bare soil, has investigated the behaviour of the coefficient values of Minnaert and C with terrain variables. The investigation in this study has revealed that the relation between terrain slope (derived from both DEM level-1 and level-2) of desert bare soil in Saudi Arabia and K and C values follow closely a 2nd order polynomial trend. K curves have taken convex shapes, whereas C curves were concave. The Minnaert (K) and C coefficients trends have shown that surface Lambertian behaviour is more pronounced on slopes facing away from the sun than on sun facing slopes. This author's newly developed terrain slope, aspect and phase angle dependant's C and Minnaert coefficients produced promising results compared to the global K and C.
Integrated and multiscale NDT for the study of architectural heritage
Luigia Nuzzo, Nicola Masini, Enzo Rizzo, et al.
The restoration of artistic and architectural heritage represents a bench mark of the cultural development of a society. To this end it is necessary to develop a suitable methodology for the analysis of the material and building components which are usually brittle and in a poor state of conservation. The paper outlines the advantages and the drawbacks in the use of Non-Destructive Testing (NDT) techniques and the need to integrate them in order to obtain a reliable reconstruction of the internal characteristics of the building elements as well as the detection of defects. In the study case we used Ground Penetrating Radar (GPR), infrared thermography (IRT), sonic and ultrasonic tests to analyze a 13th century precious rose window in Southern Italy, affected by widespread decay and instability problems. The theoretical capabilities and limitations of NDT are strictly related to the frequency content of the signals used by the different techniques. Therefore, integrating several physical methods and using different frequency bands allowed as a comprehensive, multi-scale approach to the restoration problem. This revealed to be a proper strategy in order to get high-resolution information on the building characteristics and the state of decay which could support a careful structural restoration.
Evaluation of adequacy of DEM level-1 as an alternative to level-2: in a context of a case study for radiometric normalization of desert bare soil in Saudi Arabia
Ali. I. Alomran, M. J. McCullagh
The Kingdom of Saudi Arabia has not yet had a full (national) land cover mapping survey. The very limited areas in Saudi Arabia covered by the 30m resolution DEM level-2 that is compatible with the fine and medium resolution (SPOT and TM) imagery makes it unreliable as a topographic source. The validity of the lower spatial resolution (100m) DEM level- 1 of full coverage of the Kingdom as a substitute is tested for that purpose. Two approaches to assessment were considered for this purpose. The first approach, implemented in this paper, involved a comparison between the two DEMs data with the aid of reference data, whereas in the second, not published yet, the assessment was performed on the radiometrically corrected image data using the two DEMs data. Visual and statistical analyses have revealed that differences (discrepancies) between the two DEMs increase with increase of terrain slope, indicating that possibility of DEM level-1 to replace level-2 decreases with increase in terrain slope. The possibility of DEM level-1 to be an adequate alternative to level-2 would apply in flat to moderate terrain (0° - 5°) only, and is expected to decrease as terrain orientation turns away from north (highest differences at 271° - 360°). The differences between the two DEMs for west facing slopes (i.e., 181° - 360°) are significantly higher than those for east oriented slopes (i.e., 0° - 180°).
Ring structure characteristics of South Ordos basin and its control factors in the deep
Fengjie Yang, Baiquan Xu, Hongkui Li, et al.
According to the synthetical analysis of remote sensing information and geophysical data, the late-reformation characteristics of the South Ordos basin in the Late Mesozoic and the Cenozoic is researched with the former research results and the field work. The result shows that the margin and inside of the basin are all reformed since late Mesozoic. Two different kinds of structure belt exist around the Ordos Basin. They are compressional thrust nappe belt and extensional faulted depression belt. The ring structure which is found in the southern Ordos basin has a diameter of more than 300km, and its movement and rotation are on the assumption that the ring has dominated by the mantle plume in the deep earth and relative movement on the surface of earth. It is testified that the ring structure is a relatively independent block, and it is significant for the coexistence of multi-energy resources in the same basin. There are also differences between the south and north part of Ordos basin in large scale lifting. That is the reason why there are differences between the south and north part of Ordos basin in the distribution of mineral resources. The seismic profile and the magnetotelluric sounding data of the ring structure show that there is a high depth of the Moho boundary comparing with the north part of Ordos basin, it convinced us that the mantle plume lifting does exist in the location of ring structure in the south part of Ordos basin. The lifting movement of Ordos basin in the Late Mesozoic and the Cenozoic may be an important factor of the changing channel of Yellow River cross the Ordos basin, it is significant for the formation and evolution of Yellow River.
Remote Sensing Modeling
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A satellite AOT derived from the ground sky transmittance measurements
H. S. Lim, M. Z. MatJafri, K. Abdullah, et al.
The optical properties of aerosols such as smoke from burning vary due to aging processes and these particles reach larger sizes at high concentrations. The objectives of this study are to develop and evaluate an algorithm for estimating atmospheric optical thickness from Landsat TM image. This study measured the sky transmittance at the ground using a handheld spectroradiometer in a wide wavelength spectrum to retrieve atmospheric optical thickness. The in situ measurement of atmospheric transmittance data were collected simultaneously with the acquisition of remotely sensed satellite data. The digital numbers for the three visible bands corresponding to the in situ locations were extracted and then converted into reflectance values. The reflectance measured from the satellite was subtracted by the amount given by the surface reflectance to obtain the atmospheric reflectance. These atmospheric reflectance values were used for calibration of the AOT algorithm. This study developed an empirical method to estimate the AOT values from the sky transmittance values. Finally, a AOT map was generated using the proposed algorithm and colour-coded for visual interpretation.
Retrieving spatial-temporal variation of land surface temperature in Tibetan Plateau for the years 2005-2006 from MODIS satellite data
Maofang Gao, Zhihao Qin, Jianjun Qiu, et al.
Tibetan Plateau serves as the sources of several big rivers such as Yangtze River and Yellow River. Due to the high elevation of the plateau, it has profound thermal and dynamical influence on both local and global climate and atmospheric circulation. Land surface temperature (LST) plays a significant role in climate change and glacier melting. In this paper we present our study on mapping land surface temperature variations for the years 2005-2006 in the plateau using MODIS satellite data. Since the plateau has a very rough ground surface that is difficult to estimate the necessary parameters for the mapping, we have developed a practical approach for LST retrieval from the MODIS thermal band data. The approach was alternated from the split window algorithm proposed by Qin et al. (2001) for NOAA-AVHRR data. Detailed methods for atmospheric transmittance and ground emissivity have been presented in the paper. Results from our study indicate that ground temperature in the plateau is featured with obvious spatial and temporal variations. Generally the temperature in winter and spring is less than 0°C and it is also not very high in summer, due to the high altitude. Because of topological form, Chaidamu Basin of the plateau has the highest temperature in summer, usually high up to above 40°C. Our study provides an alternative to understand the environmental changes in the plateau that shape significant impacts on atmospheric dynamics of East Asia and South Asia.
Novel Remote Sensing/GIS Applications
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Geoinformatics paves the way for a zoo information system
The use of modern electronic media offers new ways of (environmental) knowledge transfer. All kind of information can be made quickly available as well as queryable and can be processed individually. The Institute for Geoinformatics and Remote Sensing (IGF) in collaboration with the Osnabrueck Zoo, is developing a zoo information system, especially for new media (e.g. mobile devices), which provides information about the animals living there, their natural habitat and endangerment status. Thereby multimedia information is being offered to the zoo visitors. The implementation of the 2D/3D components is realized by modern database and Mapserver technologies. Among other technologies, the VRML (Virtual Reality Modeling Language) standard is used for the realization of the 3D visualization so that it can be viewed in every conventional web browser. Also, a mobile information system for Pocket PCs, Smartphones and Ultra Mobile PCs (UMPC) is being developed. All contents, including the coordinates, are stored in a PostgreSQL database. The data input, the processing and other administrative operations are executed by a content management system (CMS).
Aviation obstacle auto-extraction using remote sensing information
N. Zimmer, W. Lugsch, D. Ravenscroft, et al.
An Obstacle, in the aviation context, may be any natural, man-made, fixed or movable object, permanent or temporary. Currently, the most common way to detect relevant aviation obstacles from an aircraft or helicopter for navigation purposes and collision avoidance is the use of merged infrared and synthetic information of obstacle data. Several algorithms have been established to utilize synthetic and infrared images to generate obstacle information. There might be a situation however where the system is error-prone and may not be able to consistently determine the current environment. This situation can be avoided when the system knows the true position of the obstacle. The quality characteristics of the obstacle data strongly depends on the quality of the source data such as maps and official publications. In some countries such as newly industrializing and developing countries, quality and quantity of obstacle information is not available. The aviation world has two specifications - RTCA DO-276A and ICAO ANNEX 15 Ch. 10 - which describe the requirements for aviation obstacles. It is essential to meet these requirements to be compliant with the specifications and to support systems based on these specifications, e.g. 3D obstacle warning systems where accurate coordinates based on WGS-84 is a necessity. Existing aerial and satellite or soon to exist high quality remote sensing data makes it feasible to think about automated aviation obstacle data origination. This paper will describe the feasibility to auto-extract aviation obstacles from remote sensing data considering limitations of image and extraction technologies. Quality parameters and possible resolution of auto-extracted obstacle data will be discussed and presented.
Poster Session
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Historical aerial photographs: the territory of Caere
The study on the Caere territory has been realized by examination of the first historical aerial photographs (1929-1930) of this area, geographical positioning and mosaic, identify and draw all the archaeological cropmarks and remains. A 3D of the ancient environmental territory has been even realized. The study will develope adding to its wealth of unknown data, those from R.A.F., fifthies-sixthies and more recent aerial photos.
Evaluation of impacts of ecological water conveyances on hydrological processes and land cover in Tarim River basin, China, using groundwater levels and MODIS vegetation indices
Qi Shen, Jianhua Xu, Yuping Lei
Lower reaches of Tarim River, Western China is a very serious arid and desertification region. During 2000-2006, 2.36 billion cubic meters water has been transported to this area by nine terms to control regional desertification. We apply grey correlation analysis for temporal and spatial variations of groundwater levels from nine monitoring sections and corresponding MODIS vegetation indices (VI) in the third, fourth, and seventh terms of water conveyance to evaluate the impacts of ecological water conveyances on basin hydrological processes and land cover. During the terms of water conveyance, both groundwater level and VI along the canal are rising and a calculated grey incidence degree reaches 0.9. However, the increases of groundwater levels and VI gradually reduce from the source of water input in the direction of the canal and calculated grey incidence degrees were below the level of significance for a single term of water conveyance. At same time, the incidence degrees reduced significantly with increasing distances from the canal. The analysis results shows that spatial variations of changes of hydrological processes and land cover conditions caused by water input were very large, which may reduce the use efficiency of precious water resource in this region.
Drought remote sensing monitoring based on the Modified Perpendicular Drought Index method
Soil moisture and vegetation growth are the most important and direct index for drought. The interpreting to vegetation and spectrum analysis of soil are two important elements in the judgment of drought. Recently, Abduwasit Ghulam and other researchers, on the basis of the spatial distribution characters of soil moisture in near infrared spectrum, adopt the expansion analysis method and establish PDI. Later, vegetation index is introduced by establishing a new drought monitoring method MPDI after comprehensively considering about the soil moisture and vegetation growth characters. The article, directing against the drought in different periods of Henan Province, adopts the MODIS image data to undertake PDI and MPDI calculations and compares with the soil moisture data with that of the same period, concluding that: PDI and MPDI are closely related with the original data from land observation, among which the relations between MPDI and 0-20cm calculation is the closest; PDI and MPDI are all close to the drought situation concluded from the calculation of bared land and the early growth period of vegetations; MPDI is more suitable for the areas with vegetations.
Removing long-term errors from the AVHRR observation based on Normalized Difference Vegetation Index (NDVI)
Md. Z. Rahman, Leonid Roytman, Atiqur Rahman, et al.
This paper investigates Normalized Difference Vegetation Index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003. Advanced Very High Resolution Radiometer (AVHRR) weekly data for the five NOAA afternoon satellites for the China dataset is studied, for it includes a wide variety of different ecosystems represented globally. It was found that data for the years 1988, 1992, 1993, 1994, 1995 and 2000 are not stable enough compared to other years because of satellite orbit drift, and AVHRR sensor degradation. It is assumed that data from NOAA-7 (1982, 1983), NOAA-9 (1985, 1986), NOAA-11 (1989, 1990), NOAA-14 (1996, 1997), and NOAA-16 (2001, 2002) to be standard because these satellite's equator crossing time fall within 1330 and 1500, and hence maximizing the value of coefficients. The crux of the proposed correction procedure consists of dividing standard year's data sets into two subsets. The subset 1 (standard data correction sets) is used for correcting unstable years and then corrected data for this years compared with the standard data in the subset 2 (standard data validation sets). In this paper, we apply empirical distribution function (EDF) to correct this deficiency of data for the affected years. We normalize or correct NDVI data by the method of EDF compared with the standard. Using these normalized values, we estimate new NDVI time series which provides NDVI data for these years that match in subset 2 that is used for data validation.
The research of East China seacoast remote sensing image and vector data fusion
Data fusion is always a hot field in remote sensing research. It mainly includes checking, correlating, integrating and estimating multiple kinds of Data. Integration of global remote sensing image and local vector data is often necessary. In this paper, for global east Chinese high resolution remote sensing coast zone image and local vector data about ocean planning, we will introduce one way based on ArcGIS, in which the two kinds of data would be rapidly integrated. First, we change the vector data into raster data, then adjust these raster data precisely by Georeferencing module of ArcGIS, then vector and integrate data which we needed by Arcscan module of ArcGIS, at last, we program custom codes to solve the conflict between integrated new data and old data in VBA of ArcGIS. In the process, we wish to improve efficiency through a good management of map raster data.
SPOT/VEGETATION NDVI reconstruction and season monitoring in China
Multi-temporal series of satellite SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) has long time-series from 1998 to present. The convenient downloading policy make those data can be widely used all through the world. The data is used for global vegetation monitoring and variation analysis. The spring onset date reflects the vegetation growth and its feedback to climate and human activity, and become an important variable for the global climatic change and production monitoring. In this paper, the spatial spring onset date information in south and central China is portrayed, and the spring onset frequency distribution map is sketched by using the multi-year 10-days composite SPOT/VGT NDVI data. First, the long time series NDVI is reconstructed. Then a relative threshold value method is given to determine whether the vegetation begins to resuscitate. The spring onset frequency map mainly parallels the latitude. But because of the heterogeneity of vegetation and monsoon, the spring onset movements do not parallel the latitude completely.
Study of snow cover area and depth variation of the Tianshan Mountains
Based on the image characteristics of Tianshan Mountains, using multi-temporal multi-band NOAA/AVHRR, MODIS images, combined with high resolution CBERS-1/2 and ETM images, a model for estimating the area of snow cover and the depth of snow cover at different places was proposed. The snow cover variation characteristics including the distribution of snow cover, the depth of snow cover and the drawing method for snow cover were focused. Based on the model, the snow cover of the area along Tianshan Highway from 1996-2006 was studied.
Identification of mafic-ultramafic rocks using fuzzy logic classification of airborne geophysical data in the Anapu-Tuerê region, Brazilian Amazon
Cleyton de C. Carneiro, Alvaro P. Crósta, Adalene M. Silva, et al.
The Anapu-Tuerê region, in the Brazilian Amazon, is known for the occurrence of mineral deposits associated with mafic-ultramafic rocks. The spatial distribution of these rocks was investigated by integrating airborne magnetic and gamma ray spectrometry data using Geographic Information System (GIS) and fuzzy logic classification. Highest values of relevance fuzzy were associated with mafic-ultramafic rocks mapped regionally by the Brazilian Geological Survey (CPRM). Furthermore, mineral occurrences mapped by the CPRM showed good spatial correlation with the higher values of relevance fuzzy presented in this paper.
Reflectance properties and physiological responses of bulrush in wetland parks to heavy metal contamination
Wetland park ecosystems of Yangtze River Delta are located in highly populated areas and subject to high levels of contamination. Monitoring of wetlands to assess degrees of pollution damage requires periodic retrieval of information over large areas, which can be effectively accomplished by remote sensing technologies. The biophysical principles of remote sensing of vegetation under stress need to be understood in order to correctly interpret the information obtained at the scale of canopies. To determine the potential to remotely characterize and monitor pollution, plants of Bulrush, a major component of wetland park communities in Yangtze River Delta, were treated with two metals to study their sensitivity to pollutants and how this impacted their reflectance characteristics. Several growth and physiological parameters, as well as their reflectance were measured. Significant differences between treatments were found in at least some of the measured parameters in pollutants. Reflectance was sensitive to early stress levels only for cadmium. Pollutants that differ in their way of action also had different plant reflectance signatures. The high degree of correlation between spectral reflectance and plant stress by heavy metal contamination showed the potential of using remote sensing to assess the type and degree of pollution damage.
Multisource remote sensing archaeology of the Ancient Canal in Zhejiang, China
This paper was to address an issues of human settlement and environmental interaction on the archaeological Ancient Canal sites in Zhejiang province using Hyperspectral Remote Sensing technology. The reflectance spectra within the visible-near-infrared (VNIR) region of Ancient Canal ground soil samples were measured in the lab. High-resolution satellite remote sensing provides cheap and quick data resources for delineating the Ancient Canal. In this paper, the remote sensing mechanism and spectral characteristics of the Ancient Canal in remote sensing imagery were analyzed. A gray-slope algorithm is introduced, which can extract Ancient Canal information effectively and easily. Due to the extensive destroy to the Ancient Canal, it is only 1 or 2 pixels wide in IKONOS imagery. And the gray level between Ancient Canal and other objects around it is very different, that is, the change of gray level along Ancient Canal is greater than that of road and sand. Our study results showed that the feature absorption band center of Ancient Canal around 2288nm, and the bandwidth was between 2098-2335nm. The absorption features of background soils were at 2180nm and 2350nm, which were caused by clay minerals and carbonate, respectively. The Ancient Canal could be distinguished from the background soils by reflectance spectra. These two characteristics and bands threshold, the gray-slope method makes road and sand separated from the Ancient Canal easily.
The spectral and image characteristics of vegetation in the presence of heavy metals in southern China
Fengjie Yang, Na Li, Guangzhu Zhou, et al.
The principle and methodology to monitor the heavy metal pollution using hyperspectral remote sensing are put forward based on the study areas, copper mine in De-Xing and tin ore in GeJiu, and selected plants, China Sumac, Sweet Wormwood Herb, and Nephrolepis Cordifolia. In the areas defined by former information, vegetation samples and corresponding spectral data are gathered. The samples are then analyzed in chemical lab, telling us to what extent the vegetation is polluted by heavy metal. The spectral curves are also processed, and some spectral parameters are extracted, such as reflectance, blue-shift extent, position of red-edge, vegetation index, band-depth. Then the regression model from spectral characteristic parameters to heavy metal content can be built. At last, the conclusion can be attained. In copper mine area, the vegetation is polluted by seven kinds of heavy metals. As far as China Sumac, the reflectance of red band correlates the Pb content well. The reflectance of all study plants at 1240nm and 725/675(nm) correlates heavy metal content well. The reflectance of 450nm, 550nm, 670nm, 760nm, and 1240nm can be liner combined as a parameter to monitor heavy metal pollution. Besides, some band-depth can also be combined as parameters using "Enter". In a word, as an advanced technique to monitor environmental pollution, hyperspectral remote sensing has wild perspective.
Calculating geomorphic indices in SE Asia using a SRTM derived DEM: a worked example from West Sulawesi, Indonesia
Geomorphic indices like stream length gradient index (SL), mountain front sinuosity (Smf) and ratio of valley floor width to valley height (Vf) have previously been used to detect active tectonic features from observations of first order rivers and regional fault systems in areas where accurate topographic maps were available. However, areas in equatorial South East Asia present many problems, being remote, covered by dense forest and lacking full, detailed topographic surveys. Here a new approach is attempted, using results coming from the comparison of SRTM derived DEM's (SRTM-DEM) to traditional topographic 1:50,000 survey derived DEM's (TS-DEM). Neo-tectonic activity on the Palu-Koro fault in West Sulawesi was assessed using geomorphic indices calculated for major river systems (3rd up to 7th strahler order) derived from SRTM-DEM. Mountain front sinuosity indices are similar whether derived from SRTM-DEM or TS-DEM. Likewise, although the ranges differ, valley floor width to valley height ratios returns the same average value. The stream length index was influenced by systematic sensor errors in areas of extreme local relief on SRTM-DEM. A visual classification of river deflections and water gaps was performed in order to identify the best locations for wider application of geomorphic indices on the SRTM-DEM. While geomorphic calculations on SRTM-DEM's break down for flood plain valleys, yielding erroneous results, geomorphic indices may be successfully used to identify secondary fault systems in other parts of West Sulawesi.
Correction of reflectance characteristics of chosen natural and anthropogenic materials for an airborne laser scanning system
Miroslawa Kaszczuk, Marek Zygmunt, Jadwiga Mierczyk
In the work, analyses of chosen materials were presented in order to analyze the possibility of development of a laser scanning system. One showed results of research and analyses of data related to reflection characteristics of various materials with consideration of different ranks of composition and structure complication. Analyses were carried out for three wavelengths of electromagnetic radiation: λ1 = 850 nm, λ2 = 900 nm, λ3 = 1500 nm in reference to both natural and anthropogenic materials. The influence of atmospheric extinction on values of received proportions of signals for the chosen wavelengths was investigated and the method of signal correction was compiled. Correction was made taking into account character of reflection obtained from materials, various atmospheric conditions stated by the atmospheric visibility, and spectral characteristics of the atmospheric extinction. The proposed method of atmospheric extinction correction provides minimization of real values falsification and decrease in obtained measurement errors, which does not exceed the value of 5% for the analyses from a distance of 0.5 km with atmospheric visibility of 10 km, and for the analyses from a distance of 1 km with atmospheric visibility of 20 km.
Seismic waves velocity measurement with laser interferometric sensors
F. Acernese, R. Romano, F. Barone
Laser interferometry is one of the most sensitive methods for small displacement measurement for scientific and industrial applications. Interferometric techniques have been already successfully applied also to the design and implementation of very sensitive sensors for geophysical applications, like monolithic accelerometers. In this paper we describe the architecture and the expected theoretical performances of a laser interferometric velocimeter for seismic waves measurement. We analyze and discuss the experimental performances of the interferometric system, comparing the experimental results with the theoretical predictions and with the performances of a state-of the art commercial accelerometer. The results obtained are very encouraging, such as the sensitivity and stability of the interferometric system, that have been improved.
Hybrid control and acquisition system for remote control systems for environmental monitoring
Fabio Garufi, Fausto Acernese, Alfonso Boiano, et al.
In this paper we describe the architecture and the performances of a hybrid modular acquisition and control system prototype for environmental monitoring and geophysics. The system, an alternative to a VME-UDP/IP based system, is based on a dual-channel 18-bit low noise ADC and a 16-bit DAC module at 1 MHz. The module can be configured as stand-alone or mounted on a motherboard as mezzanine. Both the modules and the motherboard can send/receive the configuration and the acquired/correction data for control through a standard EPP parallel port to a standard PC for the real-time computation. The tests have demonstrated that a distributed control systems based on this architecture exhibits a delay time of less than 25 us on a single channel, i.e a sustained sampling frequency of more than 40 kHz (and up to 80 kHz). The system is now under extensive test in the remote controls of seismic sensors (to simulate a geophysics networks of sensors) of a large baseline suspended Michelson interferometer.
Multispectral and multitemporal satellite data fusion for coastal zone dynamics assessment
L. F. V. Zoran, C. Ionescu Golovanov, M. A. Zoran
This study focuses on the assessment of coastal zone land cover changes based on fusion technique of satellite remote sensing data. The evaluation of coastal zone landscapes is based upon different sub-functions which refer to landscape features such as water, soil, land-use, buildings, groundwater, biotope types. A newly proposed sub-pixel mapping algorithm was applied to a set of multispectral and multitemporal satellite data for Constantza and Black Sea coastal zone areas in Romania. A land cover classification and subsequent environmental quality analysis for change detection was done based on satellite images over a period of time from 1986 to 2006 , from Landsat TM , Landsat ETM, MODIS , IKONOS, Quickbird. Spectral signatures of different terrain features were used to separate and classify surface units of coastal zone and sub-coastal zone area.The change in the position of the coastline in Constantza area is examined in relation with the urban expansion. A distinction is made between landfill/sedimentation processes on the one hand and dredging/erosion processes on the other. A quasi-linear model was used to model the rate of shoreline change linked to anthropogenic and coastal erosion.
Merging radar data with geographic data for visual land clutter source recognition
In the recent years, radar land clutter modelling and processing have been aided with Geographic Information Systems (GIS) and geodata in a few recognised researches such as in the Lincoln Laboratory. In our clutter research, one aspect is to study the possibilities of using GIS in clutter classification in Finnish environment. Since the automation of this process causes inaccurate results and a need to identify and label various types of land clutter sources through geographic data (geodata) exists, we propose an approach based on the visual interpretation of clutter. We have created a graphical visualisation tool for merging geodata with radar data interactively, including an option to select the shown type(s) of geodata. The source identification is based on the visual observation of the output. The tool can also be utilised when verifying simulated data. In an example case, we have used the following geodata items: a base map, a terrain model, a database of tall structures, and a digital elevation model, but other types of geodata can be used as well. Although the potential to enhance the model is higher when more types of geodata are utilised, even with few carefully selected geodata items, clutter sources can be recognised adequately. This paper presents an illustrative demonstration using an air surveillance radar recording. This visual approach with the data merging tool has been useful, and the results have verified the practicability. The contribution of this paper focuses on supporting clutter classification research and improving the understanding of land clutter.
Monitoring rangeland plant community composition using spectral mixture analysis of hyperspectral remote sensing data
Nadia Rochdi, Peter Eddy, Karl Staenz, et al.
This paper investigates the abundance mapping of rangeland plant communities using hyperspectral remote sensing data. Spectral Mixture Analysis (SMA) was used to estimate the cover fraction of five rangeland components: green grass, yellow grass, litter, shrubs and soil. Two types of endmembers were assessed using canopy reflectance modeling and tested over real data. The first type is the leaf endmember based on the laboratory reflectance measurements of different samples of leaves. The second is the canopy endmember based on reflectance simulation using the canopy radiative transfer model SAIL. These two endmember types were first assessed in SMA using a number of homogenous canopy simulations with different Leaf Area Index (LAI). Subsequently, the leaf and the canopy endmembers were evaluated using ground spectra, and cover fractions were compared to actual data. Finally, both endmember types were applied in SMA to CHRIS/PROBA data to estimate the rangeland component cover fractions. Performances of leaf and canopy endmembers were evaluated based on the field knowledge of the area of interest. Results showed overall that the cover fraction estimates using the canopy endmembers tend to better agree with actual data.
Satellite-based enhancement of archaeological marks through data fusion techniques
The application of space technology to archaeological research has been paid great attention worldwide, mainly because the current availability of very high resolution (VHR) satellite imagery, such as, IKONOS (1999) and QuickBird (2001), provide valuable data for searching large areas to find potential archaeological sites. Data from VHR satellite can be very useful for the identification, management and documentation of archaeological resources. Archaeological investigation based on the use of VHR satellite images may take benefits from the integration and synergic use of both panchromatic and multispectral data. This can be achieved by using pansharpening techniques, which allow multispectral and panchromatic images to be merged. The two basic frameworks of pansharpening techniques are Component Substitution (CS), such as Intensity-Hue-Saturation (IHS) Gram-Schmidt (GS), and multiresolution analysis (MRA), such as wavelets and Laplacian pyramids (LP). In this paper, both Gram-Schmidt and Laplacian pyramids with context adaptive (CA) detail injection models were used. QB images were processed for a relevant archaeological area in Southern Italy, the ancient Siris-Heraclea, a very significant test area because it is characterized by the presence of both surface and subsurface ancient remains. Outcomes of different pansharpening techniques have been qualitatively evaluated for both surface and subsurface remains. The visual inspection clearly suggests that the quantitative evaluation of the fusion performance for archaeological applications is a critical issue, and "ad hoc" local (i.e. context-adaptive) indices need to be developed.