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Ramzi A.I.,National Authority of Remote Sensing and Space Science NARSS
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

Monitoring and mapping complex urban features (e.g. roads and buildings) from remotely sensed data multispectral and hyperspectral has gained enormous research interest. Accurate ground truth allows for high quality assessment of classified images and to verify the produced map. Ground truth can be acquired from: field using the handheld Global Positioning System (GPS) device and from Images with high resolution extracted from Google Earth in additional to field. Ground truth or training samples could be achieved from VHR satellite images such as QuickBird, Ikonos, Geoeye-1 and Wordview images. Archived images are costly for researchers in developing countries. Images from GE with high spatial resolution are free for public and can be used directly producing large scale maps, in producing LULC mapping and training samples. Google Earth (GE) provides free access to high resolution satellite imagery, but is the quality good enough to map urban areas. Costal of the Red sea, Marsa Alam could be mapped using GE images. The main objective of this research is exploring the accuracy assessment of producing large scale maps from free Google Earth imagery and to collect ground truth or training samples in limited geographical extend. This research will be performed on Marsa Alam city or located on the western shore of the Red Sea, Red sea Governorate, Egypt. Marsa Alam is located 274 km south of Hurghada. The proposed methodology involves image collection taken into consideration the resolution of collected photographs which depend on the height of view. After that, image rectification using suitable rectification methods with different number and distributions of GCPs and CPs. Database and Geographic information systems (GIS) layers were created by on-screen vectorization based on the requirement of large scale maps. Attribute data have been collected from the field. The obtained results show that the planmetric accuracy of the produced map from Google Earth Images met map scale 10 000 according to (National Map Accuracy Standards).The collect ground truth or training samples from GE images and field help in accuracy assessment of classification process. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. Source


Taha L.G.E.-D.,National Authority of Remote Sensing and Space Science NARSS
Egyptian Journal of Remote Sensing and Space Science | Year: 2014

Nile River has about 144 islands from Aswan to the Mediterranean Sea. In this research remotely sensed images have been used for the assessment of land cover changes in the Al-Monib island as part of an ongoing sustainable development of this island. The island has witnessed high rates of change in land use in the past few years. An urbanization process continues and it causes serious increases in urban areas while decreasing the amount of green areas. The most common use of many of the change detection algorithms has been to identify the change in coarse to medium spatial resolution satellite imagery. Now there is great interest in identifying the change in high spatial resolution multispectral data such as SPOT5 and QuickBird. In order to improve the quality and accuracy, different cues have been extracted such as IHS or PCA and texture derived from color image. Fuzzy classification has been performed several times utilizing from Multi-Cue integration (resulted into six classifications) for each date. Assessment of different approaches of classification (six classifications) has been performed for each date. After that fuzzy post classification comparison has been made for the best case. Value of the urban expansions for the period of 2002-2009 was calculated as 0.11 km2. The urban expansion rate had been realized as 3.04%. Another significant change was the decline in agricultural lands result was estimated to be 8.29%. The changes of landscape pattern were then analyzed using a series of spatial metrics (class level) which were derived from FRAGSTATS software. © 2014 Production and hosting by Elsevier B.V. on behalf of National Authority for Remote Sensing and Space Sciences. Source


Effat H.,National Authority of Remote Sensing and Space Science NARSS
Environmental Earth Sciences | Year: 2011

The Northern Nile Delta coastal zone in Egypt has unique environmentally sensitive conditions. The area contains a coastal lagoon protectorate El Burullus lagoon which is the landing for immigrant birds from Europe. The area contains several urban features such as an international highway, a port and some towns. Several stressors occur in the area. These are reflected by the sea level rise problem ranging between 1.2-1.3 mm/yr. The problem is magnified by land subsidence, sea water intrusion and shoreline erosion. Despite the stress, the Northern Nile Delta coastal zone is exerting severe changes. Those changes are both natural and anthropogenic causing environmental degradation of the area. This paper aims at conducting an analysis for the changes occurring and their causes. The area is studied during a period of 13 years during which major development decisions took place. Two multi-date satellite imageries, Landsat-5TM and Landsat-7 ETM+ acquired in 1987 and 2000 were used. The rectified images were classified to produce the Land use/Land cover maps and a Matrix function is applied to detect and quantify the changes that occurred in each class. A model was used to discriminate the accretion and erosion zones of the shoreline. The results of the study show that the study area is undergoing both anthropogenic and natural changes. The most significant changes are reflected in the transformation of the wetlands either to water bodies used as fish farms or dried up for urbanization amounting to 23.4 km2 or for land reclamation amounting to 25.5 km2. Eroded shoreline amounted to 6.87 km while accreted shoreline amounted to 7.97 km during the study period. The use of Remote Sensing and geographic information system techniques provided an integrated vision for understanding the various trends and patterns of changes in the study area. © Springer-Verlag Berlin Heidelberg 2011. Source


El Bastawesy M.,National Authority of Remote Sensing and Space Science NARSS | El Bastawesy M.,University of Umm Al - Qura | Ali R.R.,National Research Center of Egypt
Hydrological Processes | Year: 2013

This paper investigates the interplay of the hydrogeological characteristics, soil properties and recent land reclamation projects on the distribution of waterlogging and salinization within the Farafra Oasis. The multi-temporal remote sensing data and field observations show that new reclaimed areas have been recently cultivated in distant areas from the old agricultural land. These new cultivations have developed widespread waterlogging, seepage channels and soil salinization. Analyses of the Shuttle Radar Topography Mission digital elevation model (DEM) showed that both old and new agricultural areas are located within same closed drainage basin. The fluvial channels of these catchments, which were developed during wet climatic pluvial, have largely been obliterated by the prevailing aridity and often buried under aeolian deposits. However, the new cultivations have been developed on the fingertips of these fluvial channels, while the old fields occupy the low-level playas. The soil of the new cultivated areas is mainly lithic with a high calcium carbonate content, thus limiting the downward percolation of excess irrigation water and therefore developing perched water table and seepage through the palaeo-channels. The automatically extracted drainage networks from DEM resemble fluvial patterns and coincide with the seepage channels slowly heading toward old cultivation. The inactive alluvial channels and landforms have to be considered when planning for new cultivation in dryland catchments to better control waterlogging and salinization hazard. It is highly recommended that newly developed seepage channels have to be detected and intercepted before reaching old agriculture areas. Therefore, the 'dry-drainage' concept can be implemented as the seepage water can be conveyed into nearby playas reserved for evaporation. © 2012 John Wiley & Sons, Ltd. Source


Salem S.M.,National Authority of Remote Sensing and Space Science NARSS | Arafa S.A.,National research Institute for Astronomy and Geophysics | Ramadan T.M.,National Authority of Remote Sensing and Space Science NARSS | El Gammal E.S.A.,National Authority of Remote Sensing and Space Science NARSS
Arabian Journal of Geosciences | Year: 2013

Three types of hydrothermal alterations are recorded in Wadi El Regeita area, argillic, phyllic, and propylitic. Whole-rock analysis of representative samples of the alteration halo (1) shows a Cu, Au, and Ag content up to 1.7 wt.%, 1.6 g/t, and 4 g/t, respectively; in the alteration halo (2), these metal contents are up to 1.3 wt.%, 1.4 g/t, and 3 g/t, following the same order. The integrated remote sensing and geophysical data, as well as geological field verification, show that Wadi El Regeita area includes promising Cu ores within two hydrothermal alteration haloes. Spatial data analyses of lineaments from Landsat Enhanced Thematic Mapper (ETM) band ratio image (7/5, 5/4, 3/1) reveal the presence of alteration haloes that potentially may host Cu mineralization at south and north of El Regita Cu mine. Gravity interpretation indicates that the surveyed area is dissected by NE-SW fault zones in the central part, near Wadi El Regeita Cu mine. Ground magnetic survey data revealed that the surveyed area includes six magnetic bodies at depths ranging from 32 to 90 m, possibly recording the presence of mineralized and hydrothermally altered andesitic dykes. The half length of these dykes ranges from 600 to 1,070 m; their half thickness from 30 to 123 m and their half width from 48 to 531 m. Dyke locations coincide with surface alteration haloes (1) and (2) as indicated by the ETM band ratio image processing. The final assessment of the area, however, needs more detailed geological and geophysical studies with contributions of remote sensing techniques. © 2011 Saudi Society for Geosciences. Source

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