A Digital Elevation Model (DEM) is a digital representation of ground surface topography or terrain with different accuracies for different application fields. DEM have been applied to a wide range of civil engineering and military... more
A Digital Elevation Model (DEM) is a digital representation of ground surface
topography or terrain with different accuracies for different application fields. DEM have been
applied to a wide range of civil engineering and military planning tasks. DEM is obtained using a
number of techniques such as photogrammetry, digitizing, laser scanning, radar interferometry,
classical survey and GPS techniques. This paper presents an assessment study of DEM using
GPS (Stop&Go) and kinematic techniques comparing with classical survey. The results show that
a DEM generated from (Stop&Go) GPS technique has the highest accuracy with a RMS error of
9.70 cm. The RMS error of DEM derived by kinematic GPS is 12.00 cm.
Recently, the Precise Point Positioning (PPP) technique has been deeply investigated in surveying researches to achieve distinguished coordinates accuracy using one dual frequency GNSS instrument. In this research study, four SAPOS... more
Recently, the Precise Point Positioning (PPP) technique has been deeply investigated in surveying researches to achieve distinguished coordinates accuracy using one dual frequency GNSS instrument. In this research study, four SAPOS stations with 24 hours observation data in Baden-Württemberg State, Germany were selected to be processed. The station’s observation times were divided into different convergence times (1-hour, 2-hours, 4-hours, 6-hours, 8-hours, 12-hours and 24-hours). This paper aims to evaluate the accuracy of the static PPP solution with different convergence times using three PPP software packages, the APPS-PPP online service, the CSRS-PPP online service, and Bernese V. 5.2 software.
Together, the study indicates that, APPS-PPP online service in position3D after 4-hours 1 cm; the solution is steady after 6-hours up to 24-hours. CSRS-PPP online service shows a stable solution after 6-hours with a position3D of 1.2 cm. Bernese software provides a position3D of 1.44 cm after 6-hours and this solution is still improved to reach 1 cm after 24-hours convergence time. Obviously for this case study, the APPS-PPP online service provides the best PPP coordinate solution.
Precise Point Positioning (PPP) has been one of the major research areas in surveying in recent years to obtain cost effectively coordinates using one dual frequency GNSS instrument. The purpose of this study is to investigate the... more
Precise Point Positioning (PPP) has been one of the major research areas in surveying in
recent years to obtain cost effectively coordinates using one dual frequency GNSS instrument.
The purpose of this study is to investigate the accuracy of the kinematic PPP solution using
Bernese software for hydrographic applications. This PPP solution was compared with the
double-difference solution from Bernese software. The Virtual SAPOS
(SAtellitenPOSitionierungsdienst der deutschen Landesvermessung) reference station was
considered as a reference station.
Two kinematic trajectories have been observed within project “HydrOs (Integrated
Hydrographic Positioning System) on the Rhine River, Duisburg, Germany. This project is
launched in co-operation of the department M5 (Geodesy) of the German Federal Institute of
Hydrology (BfG) and the Institute of Engineering Geodesy at the University of Stuttgart
(IIGS).
The first kinematic trajectory shows a standard deviation for the kinematic PPP solution of 6
cm in East, 2.1 cm in North, and 6.8 cm in height. If the 5% of the measurements are
eliminated as outliers, the standard deviation values for a confidence level of 95% (SD95%)
are 5 cm in East, 1.2 cm in North and 5 cm in height. The second trajectory, which started
with 40 minutes of quasi-static observation time (non-moving vessel), achieves a more precise
solution. The standard deviation values of all measurement are 1.7 cm in East, 2.6 cm in
North, and 4.9 cm in height. For a confidence level of 95%, the PPP solution provides a
standard deviation (SD95%) of 1.5 cm for the East and North directions. Moreover, it delivers
3 cm for the height.
A new high accuracy technique using one dual frequency GNSS receiver, precise point positioning (PPP) offers the possibility of cost effectively obtaining coordinates. This study investigates the accuracy of kinematic PPP for hydrographic... more
A new high accuracy technique using one dual frequency GNSS receiver, precise point positioning (PPP) offers the possibility of cost effectively obtaining coordinates. This study investigates the accuracy of kinematic PPP for hydrographic applications on rivers, and shows results comparable to double-difference solutions.
Accuracy Assessment of Digital Elevation Models Using GPSA Digital Elevation Model (DEM) is a digital representation of ground surface topography or terrain with different accuracies for different application fields. DEM have been applied... more
Accuracy Assessment of Digital Elevation Models Using GPSA Digital Elevation Model (DEM) is a digital representation of ground surface topography or terrain with different accuracies for different application fields. DEM have been applied to a wide range of civil engineering and military planning tasks. DEM is obtained using a number of techniques such as photogrammetry, digitizing, laser scanning, radar interferometry, classical survey and GPS techniques. This paper presents an assessment study of DEM using GPS (Stop&Go) and kinematic techniques comparing with classical survey. The results show that a DEM generated from (Stop&Go) GPS technique has the highest accuracy with a RMS error of 9.70 cm. The RMS error of DEM derived by kinematic GPS is 12.00 cm.
Recently, the establishment of Continuously Operation Reference Stations (CORS) networks has been fundamental for Global Navigation Satellite Systems (GNSS)-based geomatics activities worldwide. The Egyptian Surveying Authority (ESA)... more
Recently, the establishment of Continuously Operation Reference Stations (CORS) networks has been fundamental for Global Navigation Satellite Systems (GNSS)-based geomatics activities worldwide. The Egyptian Surveying Authority (ESA) established a CORS network in 2011 adjusted to the International Terrestrial Reference Frame (ITRF) ITRF2008 (epoch 2011.8096). CORS networks' coordinates must be updated regularly to remain consistent with the latest reference frame realization, so this study aims to update the ESA CORS network to the ITRF 2014 (epoch 2019.5833) reference frame, analyze the coordinates' changes, and determine the positional directions and velocities because of tectonic movements over 2011-2019. Results show that the 2D and 3D coordinate discrepancies during that time have averages of 0.237 m and 0.253 m, respectively. Furthermore, the average direction of horizontal movements is 55.4 , and the overall 2D and 3D regional velocities are 29.7 and 31.7 mm/year, respectively. Therefore, the tectonic movements in Egypt, over the last decade, should be considered in GNSS high-accuracy geomatics activities. In addition, the developed ITRF coordinates-conversion produced accuracy in the order of 1-2 cm. Therefore, we suggest this conversion model is appropriate for GNSS surveying applications in Egypt.
This paper proposes a modification in the maximum power point tracking (MPPT) by using model predictive control (MPC). The modification scheme of the MPPT control is based on the perturb and observe algorithm (P&O). This modified control... more
This paper proposes a modification in the maximum power point tracking (MPPT) by using model predictive control (MPC). The modification scheme of the MPPT control is based on the perturb and observe algorithm (P&O). This modified control is implemented on the dc-dc multilevel boost converter (MLBC) to increase the response of the controller to extract the maximum power from the photovoltaic (PV) module and to boost a small dc voltage of it. The total system consisting of a PV model, a MLBC and the modified MPPT has been analyzed and then simulated with changing the solar radiation and the temperature. The proposed control scheme is implemented under program MA TLAB/SIMULINK and the obtained results are validated with real time simulation using dSPACE 1103 ControlDesk. The real time simulation results have been provided for principle validation.
Model predictive control has emerged as a very powerful method for controlling of electrical energy. One of the major advantages for this control is the performance of the power converters become more better comparing with the traditional... more
Model predictive control has emerged as a very powerful method for controlling of electrical energy. One of the major advantages for this control is the performance of the power converters become more better comparing with the traditional modulation control techniques. In this paper, a model predictive control is used to drive a three phase grid connected Quasi-Z-Source Inverter (qZSI) to improve the performance of the three phase injected output current. This technique uses a model of the qZSI and capacitor voltage, input inductor current and AC three phase output load currents to predict the behavior of the measured parameters. The resulting closed-loop system achieves high dynamic performance for all controlled parameters. The total system has been analyzed, simulated by using MATLAB/SIMULINK program then implement by using dSPACE 1103 to prove the idea.
This paper presents an analysis and the design of an off grid PV system for providing electricity for remote area. The system composed of de-de multilevel boost converter (MLBC) which is used for extracting maximum power from the cell. It... more
This paper presents an analysis and the design of an off grid PV system for providing electricity for remote area. The system composed of de-de multilevel boost converter (MLBC) which is used for extracting maximum power from the cell. It has been chosen to generate three de voltages at its output terminal. In addition to, a multilevel de link inverter suitable for the generated dc bus voltages. The inverter generates 7 levels at its output terminal. A maximum power point tracking (MPPT) program is designed and simulated to extract the maximum power from the PV cell. Regulation of the ac output voltage is executed by employing constant voltage and frequency control on its output voltage. To validate the studied system, analysis, simulation, and experimental results have been provided. Where inverter switch control signals are derived using multicarrier PWM switching technique. The effect of the modulation indexes on the load voltage and on the TUD has been studied.
The quasi-Z-source inverter (qZSI) has attracted much attention for motor drives and renewable energy applications due to its capability to boost or buck in a single converter stage. However, this capability is associated with different... more
The quasi-Z-source inverter (qZSI) has attracted much attention for motor drives and renewable energy applications due to its capability to boost or buck in a single converter stage. However, this capability is associated with different challenges related to the closed loop control of currents, control the DC capacitor voltage, produce three-phase AC output current with high dynamic performance and obtain continuous and low ripple input current. This paper presents a predictive control strategy for a three-phase qZSI that fulfills these requirements without adding any additional layers of control loops. The proposed controller implements a discrete-time model of the qZSI to predict the future behavior of the circuit variables for each switching state, along with a set of multi-objective control variables all in one cost function. The quasi impedance network and the AC load are considered together when designing the controller in order to obtain stability of the impedance network with a step change in the output reference. A detailed comparative investigation between the proposed controller and the conventional PI controller is presented to prove the superiority of the proposed method over the conventional control method. Simulation and experimental results are presented.
This paper presents a multi-objective economic-environmental dispatch (MOEED) model for integrated thermal, natural gas, and renewable energy systems considering both pollutant emission levels and total fuel or generation cost aspects.... more
This paper presents a multi-objective economic-environmental dispatch (MOEED) model for integrated thermal, natural gas, and renewable energy systems considering both pollutant emission levels and total fuel or generation cost aspects. Two cases are carried out with the IEEE 30-bus system by replacing thermal generation units into natural gas units to minimize the amount of toxin emission and fuel cost. Equality, inequality like active, reactive powers, prohibited operating zones (POZs) which represents poor operation in the generation cost function, and security constraints are considered as system constraints. Natural gas units (NGUs) are modeled in detail. Therefore, the flow velocity of gas and pressure pipelines are also considered as system constraints. Multi-objective optimization algorithms, namely multi-objective Harris hawks optimization (MOHHO) and multi-objective flower pollination algorithm (MOFPA) are employed to find Pareto optimal solutions of fuel or generation cost...
