A5027275580- GNSS positioning and interference
- Inertial Sensor and Navigation
- Geophysics and Gravity Measurements
- Advanced Optical Sensing Technologies
- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Remote Sensing and LiDAR Applications
- Optical Systems and Laser Technology
- Solar and Space Plasma Dynamics
- Perovskite Materials and Applications
- Space Satellite Systems and Control
- ZnO doping and properties
- Photocathodes and Microchannel Plates
- Chaos-based Image/Signal Encryption
- Ionosphere and magnetosphere dynamics
- Advanced Measurement and Metrology Techniques
- Ocular and Laser Science Research
- Biometric Identification and Security
- Digital Holography and Microscopy
- Advanced Frequency and Time Standards
- High-Temperature Coating Behaviors
- Optical Wireless Communication Technologies
- Orbital Angular Momentum in Optics
- Optical Polarization and Ellipsometry
- Organic Light-Emitting Diodes Research
National Research Institute of Astronomy and Geophysics
2003-2024
Changchun University of Science and Technology
2022
Assiut University
2021
Hokkaido University
1998
Three samples of ZnO doped with CuO as additive were prepared by solid state reaction from the calcined oxides and characterized SEM, EDX, AFM. The results revealed presence intergranular phase. Additives found to be between grains. conductivity three was measured frequency up 100KHz LCR circuit. calculated coefficients nonlinearity are shown highly dependent on frequency, concentration copper oxide, surface morphology, microstructure varistor samples. temperature dependence these will...
Abstract Bismuth and manganese oxides were mixed as source-materials using the mechanochemical technique followed by heat treatment to prepare phase Bi 2 Mn 4 O 10 . The X-Ray Diffraction (XRD) analysis was carried out obtain formed phases during process. oxide with chemical formula at 1073 K partially decomposed γ-Bi 12.8 19.2 α-Mn 3 after 5 h of milling time. variation crystallite size is obtained different time (1 h, 15 30 50 h). temperature dependency DC electrical conductivity observed...
Zinc oxide (ZnO) disc samples doped with copper as the main impurity were prepared and irradiated for 2 min by 1.064 μm semi-train of 20 ps pulses having energy 80 mJ in a spot size 5 mm diameter average pulse power density about 1.3 GW/cm .X-ray diffraction reveals large increase crystallite after laser irradiation min, which leads to consequent decrease dislocation it is inversely proportional square size.Scanning electron microscopy images show presence inter-granular phase CuO particles...
The paper concerns on the satellite laser ranging (SLR) in Egypt. three generations which can be loosely defined by their single shot root mean square precision, are discussed. generators used at Helwan half automatic and full stations described. equipments for operation of upgrading presented. observations carried out from Helwan-SLR mentioned. importance Egypt contributions to SLR network explained. modification requested increasing performance station is given.
We report about our observations during one of the major storms solar cycle, so-called St. Patrick's Day storm, which happened on 17 March 2015. The storm was first current cycle that reached level "Severe" NOAA geomagnetic scale. CME arrived at Earth 04:30UT 17th, sudden commencement (SSC) recorded ∼04:45UT followed by a quick drop SYM-H index. Kp planetary index activity had maximum value 8. z-component interplanetary magnetic field (IMF) strongly northward storm's day and altered to...
In many cases, we have few optical observations over a short time span, and most of the information generated is too limited to compute full orbit according angles-only method. This study aims develop mathematical model determine precise from observation data by least squares We used set Global Navigational Satellite Systems, which are tracked Optical Tracking Station (OSTS) at National Research Institute Astronomy Geophysics (NRIAG), Egypt, access high-quality predictions for orbits....
In this paper, the laser system used at Helwan Satellite Laser Ranging Station (H-SLR) will be in satellite's illumination as well for satellite ranging. The estimated model which describes energy and number of photons photoelectrons are investigated from received signals beam. For ranging purposes, equipment H-SLR is described also method its calibration. Range corrections due to effect atmosphere on beam discussed applied some satellites observed Helwan. illuminating space modeled computed...
In the presented paper, a model describing range equation, energy received, number of returned photons, and photoelectrons as well Time-Of-Flight, has been analytically studied. The data concerning Satellite Laser Ranging (SLR) observed from Changchun Observatory are considered to evaluate some parameters such received ground telescope Erecv, photons Np Npe. SLR-data taking into our consideration with summarised results for observations taken first quarter 2018. is applied on variety...
Abstract Existing remote sensing platforms often overlook the security of the
remote image acquisition process, creating opportunities for potential attackers
to exploit. To address this issue, paper proposes a novel optical encryption
framework (ECC DPM) based on elliptic curves and phase truncation to ensure the
secure transmission keys. Furthermore, an encryption scheme is
designed ECC DPM enable synchronous secure during data stage, ensuring that...
The present paper concerns fitting the range residuals of Satellite Laser Ranging (SLR) data using overlap technique. are characterized by its randomly distributed points. method used for is represented. results compared with those obtained when whole Chebyshev polynomial and Least Squares Method. later already applied in Helwan SLR station. We have found that technique allows us to use low degree polynomials order fit large number points and, at same time, provides better standard...
The present work concerns the study of great solar proton events during cycle 23. For this purpose, temporal behavior six indices these will be studied. These are radio flux (10.7cm) intensity, sunspot no., area, GEOS X-ray background and intensity flares optical flares.
Abstract History, Maths and Astronomy are all mixed up in an innovative educational project that is being carried out the Faculty of Education Universidad de La Laguna, Spain. Students learn how to teach (to primary school students) about shape Earth, distances Moon, Sun other planets, collecting their own data with simple instrumentation and, most important, connect ideas different disciplines. The structure contents this presented, as well examples activities out.