22,156 research outputs found

    Change Detection in Multi-temporal Images Using Multistage Clustering for Disaster Recovery Planning

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    Change detection analysis on multi-temporal images using various methods have been developed by many researchers in the field of spatial data analysis and image processing. Change detection analysis has many benefit for real world applications such as medical image analysis, valuable material detector, satellite image analysis, disaster recovery planning, and many others. Indonesia is one of the most country that encounter natural disaster. The most memorable disaster was happened in December 26, 2004. Change detection is one of the important part management planning for natural disaster recovery. This article present the fast and accurate result of change detection on multi-temporal images using multistage clustering. There are three main step for change detection in this article, the first step is to find the image difference of two multi-temporal images between the time before disaster and after disaster using operation log ratio between those images. The second step is clustering the difference image using Fuzzy C means divided into three classes. Change, unchanged, and intermediate change region. Afterword the last step is cluster the change map from fuzzy C means clustering using k means clustering, divided into two classes. Change and unchanged region. Both clustering\u27s based on Euclidian distance

    CHANGE DETECTION IN MULTI-TEMPORAL IMAGES USING MULTISTAGE CLUSTERING FOR DISASTER RECOVERY PLANNING

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    Change detection analysis on multi-temporal images using various methods have been developed by many researchers in the field of spatial data analysis and image processing. Change detection analysis has many benefit for real world applications such as medical image analysis, valuable material detector, satellite image analysis, disaster recovery planning, and many others. Indonesia is one of the most country that encounter natural disaster. The most memorable disaster was happened in December 26, 2004. Change detection is one of the important part management planning for natural disaster recovery. This article present the fast and accurate result of change detection on multi-temporal images using multistage clustering. There are three main step for change detection in this article, the first step is to find the image difference of two multi-temporal images between the time before disaster and after disaster using operation log ratio between those images. The second step is clustering the difference image using Fuzzy C means divided into three classes. Change, unchanged, and intermediate change region. Afterword the last step is cluster the change map from fuzzy C means clustering using k means clustering, divided into two classes. Change and unchanged region. Both clustering’s based on Euclidian distance

    Development of an UAS for Earthquake Emergency Response and Its Application in Two Disastrous Earthquakes

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    To support humanitarian action after a disaster, we require reliable data like high-resolution satellite images for analyses aimed to define the damages of facilities and/or infrastructures. However, we cannot obtain satellite images in few days after an event. Thus, in situ surveys are preferred. Advances in unmanned aircraft system (UAS) have promoted them to become precious tools for capturing and assessing the extents and volume of damages. Safety, flexibility, low cost, and ease of operation make UAS suitable for disaster assessment. In this chapter, we developed an example of UAS for swiftly acquiring disaster information. With the selected fixed-wing UAS, we successfully performed data acquisition at specified scales. For the image analysis, we applied a photogrammetric workflow to deal with the very high resolution of the images obtained without ground control points. The results obtained from two destructive earthquakes demonstrated that the presented system plays a key role on the processes of investigating and gathering information about a disaster in the earthquake epicentral areas, like road detection, structural damage survey, secondary disaster investigation, and quick disaster assessment. It can effectively provide disaster information in hardly entered areas to salvation headquarters for rapidly developing the relief measures

    Urban damage assessment using multimodal QuickBird images and ancillary data: the Bam and the Boumerdes earthquakes

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    International audienceRemote sensing has proved its usefulness for the crisis mitigation through situation report and damage assessment. Visual analysis of satellite images is conducted by analysts, however automatic or decision aid method are desired. We propose a semi-automatic damage assessment method based on a pair of very high spatial resolution (VHR) images and some ancillary data. It is applied to two disaster cases, for which the QuickBird images acquisition conditions differ. For each case, the two images also have very different viewing and illumination angles. Hence their comparison requires a preliminary registration; an automatic method adapted to VHR images is described. Then several change features are extracted from the buildings, and their relevance to assess damage on buildings is evaluated. Some textural features allow a damage assessment, but correlation coefficients are more efficient. Finally, a step toward the full automation of the method is done, skipping the supervision step of the classification process. We show the robustness of the global approach for both disaster cases with average performances closed to 75 % when 4 damage classes are discriminated, up to 90 % for a intact/damaged detection

    Damage assessment on buildings using very high resolution multimodal images and GIS

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    Satellite images are more and more used to prevent natural disasters and mitigate their impact on populations. Their analysis is usually manually conducted by operators. Automatic processing of very high resolution (VHR) images is critical when the images to analyse are acquired with very different acquisition angles; however, this situation is frequent in an operational scope of a natural disaster. We propose a method to assess damage on buildings using a pair of VHR images whose dates of acquisition encompass the disaster, and a geographical information system that contains the buildings footprints. It takes into account the acquisition parameters of the images. We assess its robustness as a function of the difference between the acquisition angles of the images. For this purpose, we adopt the framework of an operational scope and use six different VHR images that have been acquired successively before and during the period of interest. We show that the rate of false-alarms increases with this difference of acquisition angles. However, even in extreme conditions, damaged buildings are well detected. Our methodology leads to a global performance of the damage detection from 69 % with a difference angle of 80o, to 90 % for a difference angle around 24o

    Working towards an Improved Monitoring Infrastructure to support Disaster Management, Humanitarian Relief and Civil Security

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    Within this paper experiences and results from the work in the context of the European Initiative on Global Monitoring for Environment and Security (GMES) as they were gathered within the German Remote Sensing Data Center (DFD) are reported. It is described how data flows, analysis methods and information networks can be improved to allow better and faster access to remote sensing data and information in order to support the management of crisis situations. This refers to all phases of a crisis or disaster situation, including preparedness, response and recovery. Above the infrastructure and information flow elements, example cases of different crisis situations in the context of natural disasters, humanitarian relief activities and civil security are discussed. This builds on the experiences gained during the very active participation in the network of Excellence on Global Monitoring for Stability and Security (GMOSS), the GMES Service Element RESPOND, focussing on Humanitarian Relief Support and supporting the International Charter on Space and Major Disasters as well as while linking closely to national, European and international entities related to civil human security. It is suggested to further improve the network of national and regional centres of excellence in this context in order to improve local, regional and global monitoring capacities. Only when optimum interoperability and information flow can be achieved among systems and data providers on one hand side and the decision makers on the other, efficient monitoring and analysis capacities can be established successfully

    Investigating SAR algorithm for spaceborne interferometric oil spill detection

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    The environmental damages and recovery of terrestrial ecosystems from oil spills can last decades. Oil spills have been responsible for loss of aquamarine lives, organisms, trees, vegetation, birds and wildlife. Although there are several methods through which oil spills can be detected, it can be argued that remote sensing via the use of spaceborne platforms provides enormous benefits. This paper will provide more efficient means and methods that can assist in improving oil spill responses. The objective of this research is to develop a signal processing algorithm that can be used for detecting oil spills using spaceborne SAR interferometry (InSAR) data. To this end, a pendulum formation of multistatic smallSAR carrying platforms in a near equatorial orbit is described. The characteristic parameters such as the effects of incidence angles on radar backscatter, which support the detection of oil spills, will be the main drivers for determining the relative positions of the small satellites in formation. The orbit design and baseline distances between each spaceborne SAR platform will also be discussed. Furthermore, results from previous analysis on coverage assessment and revisit time shall be highlighted. Finally, an evaluation of automatic algorithm techniques for oil spill detection in SAR images will be conducted and results presented. The framework for the automatic algorithm considered consists of three major steps. The segmentation stage, where techniques that suggest the use of thresholding for dark spot segmentation within the captured InSAR image scene is conducted. The feature extraction stage involves the geometry and shape of the segmented region where elongation of the oil slick is considered an important feature and a function of the width and the length of the oil slick. For the classification stage, where the major objective is to distinguish oil spills from look-alikes, a Mahalanobis classifier will be used to estimate the probability of the extracted features being oil spills. The validation process of the algorithm will be conducted by using NASA’s UAVSAR data obtained over the Gulf of coast oil spill and RADARSAT-1 dat
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