Mervat Refaat

Benha University

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Maher Amin

Benha University

Ali El Sagheer

Benha University

Omayma Obada

Benha University

Mohamed Freeshah

Benha University

Mohamed Elshewy

Al-Azhar University

Ayman El-Shehaby

Benha University

Ebtesam Nafie

City of Hope

Xiaodong Ren

Wuhan University

M. H. Awwad

Al-Azhar University

A. Rayan

National Research Institute of Astronomy and Geophysics

Cooperative Institutions

Benha University

Wuhan University

Al-Azhar University

State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing

National Authority for Remote Sensing and Space Sciences

Al-Azhar University

National Research Institute of Astronomy and Geophysics

Cairo University

State University of Land Use Planning

City of Hope

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Shark Liver Oil Protects the Chromosome and Sperm of Mice against the Cytotoxicity of Taxotere

Benha Journal of Applied Sciences (2018)

Mohamed Zowail Mervat Refaat M. H. Awwad Eman Khater Ebtesam Nafie

The natural ether-lipids 1-O-alkylglycerols from shark liver oil (SLO) supposed to improve sperm motility and fertility.Also, they reduce the side effects of radiotherapy, inhibit tumor growth and both stimulate and modulate immune responses.This study aimed to show the protective effect of SLO against the side effects of Taxotere on mice chromosomes and sperms.Thirty adult male mice weight (23-27gm) were used in this study.The animals were housed in plastic cages at the same temperature and humidity conditions.They were divided into 6 groups each one contains 5 male mice that were used for studying chromosomal abnormalities and sperm head and tail morphology by using classical cytogenetic methods.The administered doses of Taxotere were 8 mg/kg.Mice injected SLO at a dose of (10 mg/kg/day).Results showed that Taxotere caused structural and numerical chromosomal aberration including deletion, centromeric attenuation, ring, monoploidy, and polyploid.It also caused sperm head and tail abnormalities such as without hook, amorphous, hummer head and sperm with a coiled tail.Our results proved the efficiency of SLO to protect mice chromosomes and sperms against the cytotoxic effect of Taxotere.

10.21608/bjas.2018.191064

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Developing Updated Basemap for River Nile in Egypt Using Free Sources Satellite Images

American Journal of Geographic Information System (2018)

Ali El Sagheer Maher Amin Mervat Refaat Omayma Obada

The uses of the River Nile can be improved in transportation, tourism and other important fields by using Geographical Information System (GIS) and Remote Sensing techniques as creating River Nile basemap for monitoring River Nile resources. In order to develop an updated base map for River Nile in Egypt, it was necessary to address, review, assesses and evaluates the available different free sources satellite images. In this paper, four study areas over Egypt were chosen and definite points were observed for those areas using GPS techniques. The same specified points were determined on the available free satellite images. Assessment for free sources satellite images, in terms of horizontal accuracy, and depending on the available images resolution, has been evaluated. The obtained results of Root Mean Square Error (RMSEr) for horizontal coordinate differences in small areas vary from 1.57 m to 5.06 m, and large area varies from 8.52 m to 9.15 m. Image registration techniques were applied using two dimensional transformations process in the previous four study areas between the two free sources satellite images (Image-to-Image registration) and between satellite image and GPS points (Image-to-Ground registration) to get the register image points with suitable accuracy comparable with GPS accuracy and images resolution. The transformation parameters (Scale (s), Rotation (θ) and Translations (ΔX, ΔY)) are calculated for the areas under consideration. The Root Mean Square Error (RMSEr) obtained from the transformation process in small areas varies from 1.94 m to 2.86 m and in large area varies from 7.428 m to 8.586 m. Then these calculated transformation parameters used to transform other points onto the required system. This approach can be used in different areas which have lack of GPS observed points to calculate semi-ground points from transformed measured free imagery points with suitable accuracy compared with the accuracy of GPS and images resolution. Finally, using free sources satellite images with Geographic Information System Application to building an updated basemap for River Nile in Egypt.

Image registration

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Crustal movement and crustal structure of the Gulf of Suez margins

Journal of Spatial Science (2015)

Ahmed Hosny Mervat Refaat A. Rayan

In this study, the crustal movement and structures beneath the Gulf margins are investigated by applying Global Positioning System (GPS) and receiver function techniques. Our results revealed the symmetrical crustal thickness beneath west and east Gulf margins with average crustal thickness of 26 km near the coast and 32–35 km inland. The crustal movements through the three parts of the Gulf of Suez (north, middle and south) are measured with an average rate of displacement 11 ± 2 mm/yr on the eastern side and 11.8 ± 2 mm/yr on the western side, while in the middle part a higher displacement rate is observed on the east bank than on the west. When considering the average measurement, a symmetric displacement rate is observed at the two Gulf of Suez margins. In fact, our study produced a new idea and contributed to proving the symmetrical rift system of the Gulf of Suez.

10.1080/14498596.2015.1007174

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Developing a Soil Salinity Model from Landsat 8 Satellite Bands Based on Advanced Machine Learning Algorithms

Journal of the Indian Society of Remote Sensing (2024)

Mohamed Elshewy Mostafa Mohamed Mervat Refaat

Abstract Soil salinity is a significant challenge in numerous regions across the globe, including Egypt. The potential consequences encompass negative impacts on crop yield, human well-being, and eco-logical systems. The utilization of remote sensing and machine learning techniques is increasingly becoming recognized as cost-effective methodologies for the cartographic representation of soil salinity. The present work employed Landsat 8 satellite imaging data and sophisticated machine learning techniques to delineate and assess soil salinity levels in Sharkia Governorate, Egypt. In this work, several machine learning techniques were employed to forecast the salinity values of Total Dissolved Solids (TDS) in the designated geographical region. These algorithms encompassed support vector machines (SVM), regression trees, Gaussian linear regression, and tree-based ensemble in addition to linear regression analysis. A variety of instances were generated to develop an optimal model that accurately characterizes the salinity TDS values within the study area. This was achieved by utilizing the band values extracted from the Landsat 8 satellite imagery. The approach that demonstrated the highest performance was observed when employing the Blue, Red, and shortwave infrared bands in conjunction with the SVM-Quadratic SVM model. This particular configuration yielded an R2 value of 0.86 and an RMSE value of 175.98. The findings of this work demonstrate the feasibility of precisely mapping soil salinity through the utilization of Landsat 8 satellite imaging data and machine learning techniques. The provided data can be utilized to identify regions characterized by elevated levels of soil salinity, as well as for the formulation of effective approaches aimed at addressing this issue.

10.1007/s12524-024-01841-1

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Water Resources Management Using Satellite Remote Sensing (Case study in Lake Tana and Lake Nasser)

AUSTRALIAN JOURNAL OF BASIC AND APPLIED SCIENCES (2018)

Ali El Sagheer Maher Amin Mervat Refaat Omayma Obada

10.22587/ajbas.2018.12.7.1

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A novel approach for optimizing regional geoid modeling over rugged terrains based on global geopotential models and artificial intelligence algorithms

The Egyptian Journal of Remote Sensing and Space Science (2024)

Mohamed Elshewy Phung Trung Thanh Amr M. Elsheshtawy Mervat Refaat Mohamed Freeshah

Geopotential

Geopotential height

10.1016/j.ejrs.2024.09.002

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Analysis of Atmospheric and Ionospheric Variations Due to Impacts of Super Typhoon Mangkhut (1822) in the Northwest Pacific Ocean

Remote Sensing (2021)

Mohamed Freeshah Xiaohong Zhang Erman Şentürk Muhammad Arqim Adil B. G. Mousa

The Northwest Pacific Ocean (NWP) is one of the most vulnerable regions that has been hit by typhoons. In September 2018, Mangkhut was the 22nd Tropical Cyclone (TC) over the NWP regions (so, the event was numbered as 1822). In this paper, we investigated the highest amplitude ionospheric variations, along with the atmospheric anomalies, such as the sea-level pressure, Mangkhut’s cloud system, and the meridional and zonal wind during the typhoon. Regional Ionosphere Maps (RIMs) were created through the Hong Kong Continuously Operating Reference Stations (HKCORS) and International GNSS Service (IGS) data around the area of Mangkhut typhoon. RIMs were utilized to analyze the ionospheric Total Electron Content (TEC) response over the maximum wind speed points (maximum spots) under the meticulous observations of the solar-terrestrial environment and geomagnetic storm indices. Ionospheric vertical TEC (VTEC) time sequences over the maximum spots are detected by three methods: interquartile range method (IQR), enhanced average difference (EAD), and range of ten days (RTD) during the super typhoon Mangkhut. The research findings indicated significant ionospheric variations over the maximum spots during this powerful tropical cyclone within a few hours before the extreme wind speed. Moreover, the ionosphere showed a positive response where the maximum VTEC amplitude variations coincided with the cyclone rainbands or typhoon edges rather than the center of the storm. The sea-level pressure tends to decrease around the typhoon periphery, and the highest ionospheric VTEC amplitude was observed when the low-pressure cell covers the largest area. The possible mechanism of the ionospheric response is based on strong convective cells that create the gravity waves over tropical cyclones. Moreover, the critical change state in the meridional wind happened on the same day of maximum ionospheric variations on the 256th day of the year (DOY 256). This comprehensive analysis suggests that the meridional winds and their resulting waves may contribute in one way or another to upper atmosphere-ionosphere coupling.

Typhoon

10.3390/rs13040661

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Evaluation of Land Use Maps Using Remote Sensing and GIS

AUSTRALIAN JOURNAL OF BASIC AND APPLIED SCIENCES (2018)

Maher Amin Ayman El-Shehaby Mervat Refaat Gehad Elsayad

Land information system

10.22587/ajbas.2018.12.3.6

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Estimating Earth’s Surface Deformation from GPS and DInSAR Data Integration

AUSTRALIAN JOURNAL OF BASIC AND APPLIED SCIENCES (2018)

A Saad Ayman El-Shehaby Mervat Refaat Reda Fekry

Earth surface

10.22587/ajbas.2018.12.6.1

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Building Automated Navigation System for River Nile in Egypt Using Remote Sensing and GIS Techniques

American Journal of Geographic Information System (2018)

Ali El Sagheer Maher Amin Mervat Refaat Omayma Obada

In recent years the Government of Egypt initiated the efforts towards developing a navigation system in River Nile in Egypt. These efforts will increase the revenue from tourism; reduce the cost of shipping and the load on transportation network and overcome tourism ships which stuck near Luxor and Aswan city that happed every year during the peak of the tourism season between November-February due to decrease in water level that can affect 300 tourism boats with a capacity for accommodating over 60,000 tourists per week. Developing River Nile navigation system depends on the availability of updated data and information for River Nile depths all over the year in order to identify the best route that can be used for ships. River Nile water level always changes that effect changing of River Nile depths. This point is critical and has entertained thinking about using remote sensing technology that can derive bathymetric data from high-resolution multispectral satellite imagery. In this paper, Stumpf algorithm for estimating shallow water depth from multispectral data is applied in our study area near Esna district. This methodology is based on linear logarithm ratio model between image bands; the retrieved bathymetry is compared with echo sounder data. The validation results show that the applied method has acceptable performance, and the Root Mean Square Error (RMSEr) is 0.79 m. Then the second part in this paper building an automated navigation system for River Nile fleet in Egypt using Linear Reference and Dynamic Segmentation techniques based on the above retrieved bathymetry data and the other available collected data from different resources. The developed application is integration between Geomatics Engineering and Software Engineering on how maps, data, functions and information were used in a useful way using programming language to allow operation of all inertial navigation.

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