Wassim Katerji - Academia.edu (original) (raw)
Papers by Wassim Katerji
Location-based services (LBS) highly rely on the location of the mobile user in order to provide ... more Location-based services (LBS) highly rely on the location of the mobile user in order to provide the service tailored to that location. This location is calculated differently depending on the technology available in the used mobile device. No matter which technology is used, the location will never be calculated 100% correctly; instead there will always be a margin of error generated during the calculation, which is referred to as positional accuracy. This research has reviewed the eight most common positioning technologies available in the major current smart-phones and assessed their positional accuracy with respect to its usage by LBS applications. Given the vast majority of these applications, this research classified them into thirteen categories, and these categories were also classified depending on their level criticality as low, medium, or high critical, and whether they function indoor or outdoor. The accuracies of different positioning technologies are compared to these ...
The objective of this paper is to demonstrate the usage of Geographic Information Systems (GIS) i... more The objective of this paper is to demonstrate the usage of Geographic Information Systems (GIS) in optimally distributing a set of permanent stationary sensors to ensure the reliable functioning of a wireless sensors network (WSN) in the case of forest fires. Once a fire occurs, an additional set of sensors are air-dropped over the area. Both stationary and airdropped sensors will form a network that will transmit back to the base critical real-time information. Collected information, such as temperature, wind direction, humidity, pressure and pollution level, will enable the fire fighters to accurately assess the situation before heading on-site. A GIS based, as well as a terrain and obstacle aware procedure is presented in this paper which enables the optimal distribution of the stationary nodes and permits the calculation of several performance parameters such as the network connectivity in 2D and 3D, the total number of generated sub-networks. The proposed procedure is based on ...
Analisis de precision en modelos digitales de elevacion globales. ABSTRACT: Terrain-Based Analysi... more Analisis de precision en modelos digitales de elevacion globales. ABSTRACT: Terrain-Based Analysis results in derived products from an input DEM and these products are needed to perform various analyses. To efficiently use these products in decision-making, their accuracies must be estimated systematically. This paper proposes a procedure to assess the accuracy of these derived products, by calculating the accuracy of the slope dataset and its significance, taking as an input the accuracy of the DEM. Based on the output of previously published research on modeling the relative accuracy of a DEM, specifically ASTER and SRTM DEMs with Lebanon coverage as the area of study, analysis have showed that ASTER has a low significance in the majority of the area where only 2% of the modeled terrain has 50% or more significance. On the other hand, SRTM showed a better significance, where 37% of the modeled terrain has 50% or more significance. Statistical analysis deduced that the accuracy of ...
International Journal of Science and Research (IJSR), Jan 5, 2016
To understand the cropped areas and assess seasonal water supply for irrigation, remote sensing-b... more To understand the cropped areas and assess seasonal water supply for irrigation, remote sensing-based crop classification was conducted on satellite imagery data for a pilot area in the Bekaa Valley, Lebanon, during the 2011-2012 growing years. The crop classification was achieved using three sets of RapidEye and Landsat7 ETM+ (Enhanced Thematic Mapper Plus) images acquired in early (May), mid (July) and late (September) of 2011 and 2012 growing years, respectively. Field crop data were obtained throughout the growing seasons in well-defined farmers' plots before the images acquisitions using a hand-held GPS (Global Positioning System) Unit. Ten crop classification profiles and three non-crop profiles were derived for each year from the different class signatures in the preselected bands of the two satellite data. Then, image-derived results were checked for accuracy and used to produce cropping maps within GIS (Geographic Information System).These maps enabled us to define different cropping calendars and determine seasonal irrigation water requirements (IWRs) at the pilot area level. IWRs were calculated for the surveyed crops as the product of the produced cropping maps and net irrigation requirements (NIR)calculated by means of MOPECO(Economic Optimization Model for Irrigation Water Management). The results were compared with the Litani River Authority Database (LRAD) and found a good agreement. The classification results of RapidEye images (2011) compared quite well in the whole test area with Landsat derived crop maps (2012). The overall accuracy of the classification against the field data ranges from 84% to 95%. In addition, crop classification profiles appeared consistent with field crop observations, even though a slight variation was noted. The examination of the crop maps showed decreases of as much as 7%, 30% and 5%inbareland, woodland and fallow areas, respectively, in 2012 when compared to 2011. Data showed that these decreases were reported as increases in wheat (15%), fruit trees (11%), olive (6%), and vineyard (3%). The increased cropland that was observed in 2012 was accompanied by an increase in the amount of water allocated from the Canal 900 irrigation conveyor in comparison with that of 2011. This study presented an example of remote sensing application for water allocation in agriculture. It was concluded that satellite imagery was essential for the definition of the existing cropping patterns in the pilot area and helped better estimate seasonal irrigation needs at the scheme level. The proposed methodology may help irrigation deciders to better assess water resources with respect to the surveyed cropped areas.
Open Geosciences, 2016
Global and nation-wide DEM do not preserve the same height accuracy throughout the area of study.... more Global and nation-wide DEM do not preserve the same height accuracy throughout the area of study. Instead of assuming a single RMSE value for the whole area, this study proposes a vario-model that divides the area into sub-regions depending on the land-use / landcover (LULC) classification, and assigns a local accuracy per each zone, as these areas share similar terrain formation and roughness, and tend to have similar DEM accuracies. A pilot study over Lebanon using the SRTM and ASTER DEMs, combined with a set of 1,105 randomly distributed ground control points (GCPs) showed that even though the inputDEMs have different spatial and temporal resolution, and were collected using difierent techniques, their accuracy varied similarly when changing over difierent LULC classes. Furthermore, validating the generated vario-models proved that they provide a closer representation of the accuracy to the validating GCPs than the conventional RMSE, by 94% and 86% for the SRTMand ASTER respectiv...
Location-based services (LBS) highly rely on the location of the mobile user in order to provide ... more Location-based services (LBS) highly rely on the location of the mobile user in order to provide the service tailored to that location. This location is calculated differently depending on the technology available in the used mobile device. No matter which technology is used, the location will never be calculated 100% correctly; instead there will always be a margin of error generated during the calculation, which is referred to as positional accuracy. This research has reviewed the eight most common positioning technologies available in the major current smart-phones and assessed their positional accuracy with respect to its usage by LBS applications. Given the vast majority of these applications, this research classified them into thirteen categories, and these categories were also classified depending on their level criticality as low, medium, or high critical, and whether they function indoor or outdoor. The accuracies of different positioning technologies are compared to these ...
The objective of this paper is to demonstrate the usage of Geographic Information Systems (GIS) i... more The objective of this paper is to demonstrate the usage of Geographic Information Systems (GIS) in optimally distributing a set of permanent stationary sensors to ensure the reliable functioning of a wireless sensors network (WSN) in the case of forest fires. Once a fire occurs, an additional set of sensors are air-dropped over the area. Both stationary and airdropped sensors will form a network that will transmit back to the base critical real-time information. Collected information, such as temperature, wind direction, humidity, pressure and pollution level, will enable the fire fighters to accurately assess the situation before heading on-site. A GIS based, as well as a terrain and obstacle aware procedure is presented in this paper which enables the optimal distribution of the stationary nodes and permits the calculation of several performance parameters such as the network connectivity in 2D and 3D, the total number of generated sub-networks. The proposed procedure is based on ...
Analisis de precision en modelos digitales de elevacion globales. ABSTRACT: Terrain-Based Analysi... more Analisis de precision en modelos digitales de elevacion globales. ABSTRACT: Terrain-Based Analysis results in derived products from an input DEM and these products are needed to perform various analyses. To efficiently use these products in decision-making, their accuracies must be estimated systematically. This paper proposes a procedure to assess the accuracy of these derived products, by calculating the accuracy of the slope dataset and its significance, taking as an input the accuracy of the DEM. Based on the output of previously published research on modeling the relative accuracy of a DEM, specifically ASTER and SRTM DEMs with Lebanon coverage as the area of study, analysis have showed that ASTER has a low significance in the majority of the area where only 2% of the modeled terrain has 50% or more significance. On the other hand, SRTM showed a better significance, where 37% of the modeled terrain has 50% or more significance. Statistical analysis deduced that the accuracy of ...
International Journal of Science and Research (IJSR), Jan 5, 2016
To understand the cropped areas and assess seasonal water supply for irrigation, remote sensing-b... more To understand the cropped areas and assess seasonal water supply for irrigation, remote sensing-based crop classification was conducted on satellite imagery data for a pilot area in the Bekaa Valley, Lebanon, during the 2011-2012 growing years. The crop classification was achieved using three sets of RapidEye and Landsat7 ETM+ (Enhanced Thematic Mapper Plus) images acquired in early (May), mid (July) and late (September) of 2011 and 2012 growing years, respectively. Field crop data were obtained throughout the growing seasons in well-defined farmers' plots before the images acquisitions using a hand-held GPS (Global Positioning System) Unit. Ten crop classification profiles and three non-crop profiles were derived for each year from the different class signatures in the preselected bands of the two satellite data. Then, image-derived results were checked for accuracy and used to produce cropping maps within GIS (Geographic Information System).These maps enabled us to define different cropping calendars and determine seasonal irrigation water requirements (IWRs) at the pilot area level. IWRs were calculated for the surveyed crops as the product of the produced cropping maps and net irrigation requirements (NIR)calculated by means of MOPECO(Economic Optimization Model for Irrigation Water Management). The results were compared with the Litani River Authority Database (LRAD) and found a good agreement. The classification results of RapidEye images (2011) compared quite well in the whole test area with Landsat derived crop maps (2012). The overall accuracy of the classification against the field data ranges from 84% to 95%. In addition, crop classification profiles appeared consistent with field crop observations, even though a slight variation was noted. The examination of the crop maps showed decreases of as much as 7%, 30% and 5%inbareland, woodland and fallow areas, respectively, in 2012 when compared to 2011. Data showed that these decreases were reported as increases in wheat (15%), fruit trees (11%), olive (6%), and vineyard (3%). The increased cropland that was observed in 2012 was accompanied by an increase in the amount of water allocated from the Canal 900 irrigation conveyor in comparison with that of 2011. This study presented an example of remote sensing application for water allocation in agriculture. It was concluded that satellite imagery was essential for the definition of the existing cropping patterns in the pilot area and helped better estimate seasonal irrigation needs at the scheme level. The proposed methodology may help irrigation deciders to better assess water resources with respect to the surveyed cropped areas.
Open Geosciences, 2016
Global and nation-wide DEM do not preserve the same height accuracy throughout the area of study.... more Global and nation-wide DEM do not preserve the same height accuracy throughout the area of study. Instead of assuming a single RMSE value for the whole area, this study proposes a vario-model that divides the area into sub-regions depending on the land-use / landcover (LULC) classification, and assigns a local accuracy per each zone, as these areas share similar terrain formation and roughness, and tend to have similar DEM accuracies. A pilot study over Lebanon using the SRTM and ASTER DEMs, combined with a set of 1,105 randomly distributed ground control points (GCPs) showed that even though the inputDEMs have different spatial and temporal resolution, and were collected using difierent techniques, their accuracy varied similarly when changing over difierent LULC classes. Furthermore, validating the generated vario-models proved that they provide a closer representation of the accuracy to the validating GCPs than the conventional RMSE, by 94% and 86% for the SRTMand ASTER respectiv...