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Developing an accurate Lowest Astronomical Tide (LAT) in a continuous form is essential for many maritime applications as it can be employed to develop an accurate continuous vertical control datum for hydrographic surveys applications and to produce accurate dynamic electronic navigation charts for safe maritime navigation by mariners. The LAT can be developed in a continuous (surface) using an estimated LAT surface model from the hydrodynamic ocean model along with coastal discrete LAT point values derived from tide gauges data sets to provide the corrected LAT surface model. In this paper, an accurate LAT surface model was developed for the Red Sea case study using a Maximum Likelihood Estimator (MLE) with multiple hydrodynamic ocean models hybridization, namely, WebTide, FES2014, DTU10, and EOT11a models. It was found that the developed optimal hybrid LAT model using MLE with multiple hydrodynamic ocean models hybridization ranges from 0.1 m to 1.63 m, associated with about 2.4 cm of uncertainty at a 95% confidence level in the Red Sea case study area. To validate the accuracy of the developed model, the comparison was made between the optimal hybrid LAT model developed from multiple hydrodynamic ocean models hybridization using the MLE method with the individual LAT models estimated from individual WebTide, FES2014, DTU10, or EOT11a ocean models based on the associated uncertainties estimated at a 95% confidence level. It was found that the optimal hybrid LAT model accuracy is superior to the individual LAT models estimated from individual ocean models with an improvement of about 50% in average, based on the estimated uncertainties. The importance of developing optimal LAT surface model using the MLE method with multiple hydrodynamic ocean models hybridization in this paper with few centimeters level of uncertainty can lead to accurate continuous vertical datum estimation that is essential for many maritime applications.
Mohammed El-Diasty. Optimal Lowest Astronomical Tide Estimation Using Maximum Likelihood Estimator with Multiple Ocean Models Hybridization. ISPRS International Journal of Geo-Information 2020, 9, 327 .
AMA StyleMohammed El-Diasty. Optimal Lowest Astronomical Tide Estimation Using Maximum Likelihood Estimator with Multiple Ocean Models Hybridization. ISPRS International Journal of Geo-Information. 2020; 9 (5):327.
Chicago/Turabian StyleMohammed El-Diasty. 2020. "Optimal Lowest Astronomical Tide Estimation Using Maximum Likelihood Estimator with Multiple Ocean Models Hybridization." ISPRS International Journal of Geo-Information 9, no. 5: 327.
Recently, the Saudi KSACORS network GNSS stations were developed by Saudi Geodetic Commission for Survey (GCS) to maintain an accurate GNSS positioning solution within Saudi Arabia coverage area. This paper evaluates the performance of real-time KSACORS-based network-RTK (NRTK) GNSS positioning solution for Saudi coastal maritime navigation and investigates whether the achieved accuracy can meet the International Maritime Organization (IMO) standards. To examine the performance of the real-time KSACORS-based NRTK GNSS positioning solution accuracy, kinematic data from a dual frequency GNSS data that collected onboard a vessel was processed with the KSACORS-based NRTK GNSS positioning techniques and compared with the post-processed PPK GNSS positioning solution. The root-mean-squares error (RMS) of the 2D horizontal position for the real-time KSACORS-based NRTK GNSS solution was estimated and was investigated whether RMS can fulfill the IMO standards for Saudi coastal maritime navigation. It is shown that the real-time KSACORS-based NRTK GNSS positioning solution fulfills IMO requirements at 95% confidence level for the three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with an accuracy requirement ranges from 10 to 0.1 m.
Mohammed El-Diasty. A real-time KSACORS-based NRTK GNSS positioning system for Saudi coastal navigation. Australian Journal of Maritime & Ocean Affairs 2020, 12, 95 -107.
AMA StyleMohammed El-Diasty. A real-time KSACORS-based NRTK GNSS positioning system for Saudi coastal navigation. Australian Journal of Maritime & Ocean Affairs. 2020; 12 (2):95-107.
Chicago/Turabian StyleMohammed El-Diasty. 2020. "A real-time KSACORS-based NRTK GNSS positioning system for Saudi coastal navigation." Australian Journal of Maritime & Ocean Affairs 12, no. 2: 95-107.
Multibeam echosounding technique is used to provide sea-floor mapping with relatively high-quality level and requires an accurate positioning and attitude system. Integration of Global Navigation Satellite System (GNSS) and inertial navigation system (INS) is widely used for positioning and attitude control and is carried out using an inertial unit integrated with GNSS solution to provide the required accuracy. Recently, the Kingdom of Saudi Arabia Continuously Operating Reference Station (KSACORS) network GNSS stations were developed by the Saudi Geodetic Commission for Survey (GCS) to maintain an accurate GNSS positioning solution for governmental and private sectors within Saudi Arabia coverage area. This paper investigates the performance of the KSACORS-based network GNSS-INS integration for Saudi coastal hydrographic surveys and also investigates whether the archived accuracy fulfill International Hydrographic Organization (IHO) standards for all survey orders. To meet this objective, the KSACORS-based network real-time-kinematic (NRTK) and network post-processed kinematic (NPPK) solutions are integrated with INS solution. The implementation of the KSACORS-based NRTK and NPPK GNSS-INS integration methods shows that centimeters and arc-minutes level of accuracies for position and attitude solutions, respectively, can be successfully achieved throughout onshore hydrographic surveys. Also, it is shown that the KSACORS-based NRTK GNSS-INS and NPPK GNSS-INS integration systems fulfill IHO standards for all survey orders and can be employed for Saudi coastal multibeam echosounding surveys. The significant contribution of the paper is that it implemented the performance of KSACORS-based NRTK GNSS-INS and NPPK GNSS-INS integration systems for hydrographic surveying application and validated their accuracies against IHO standards.
Mohammed El-Diasty. Evaluation of KSACORS-based network GNSS-INS integrated system for Saudi coastal hydrographic surveys. Geomatics, Natural Hazards and Risk 2020, 11, 1426 -1446.
AMA StyleMohammed El-Diasty. Evaluation of KSACORS-based network GNSS-INS integrated system for Saudi coastal hydrographic surveys. Geomatics, Natural Hazards and Risk. 2020; 11 (1):1426-1446.
Chicago/Turabian StyleMohammed El-Diasty. 2020. "Evaluation of KSACORS-based network GNSS-INS integrated system for Saudi coastal hydrographic surveys." Geomatics, Natural Hazards and Risk 11, no. 1: 1426-1446.
The observed hydrographic surveying data from multibeam echosounder system (MBES) contains sounding and backscatter intensity data that can be utilized in many coastal and marine applications such as marine geological and environmental investigations. In this paper, the seabed sediments mapping for Sharm Obhur (Obhur Creek) was derived using backscatter intensity data. The backscatter data were radiometrically and geometrically corrected to produce a seabed backscatter mosaic for Sharm Obhur study area. Then, the angular response analysis was implemented to derive the seabed sediment’s grain size, classification (gravel, sand and mud) and associated confidence level values that identify the quality of the classification method implemented in this paper. It was shown that the mouth in the south of the Sharm Obhur mainly contains sand sediments, however, the north side of the Sharm Obhur contains mud sediments and gravel sediments can be seen in very small areas. Moreover, it was found that the successful rate of classification is 90% based on the estimated confidence values. To validate the derived seabed sedimentation map, a comparison was made between the grab sampling results reported in the literature and the seabed sediments types derived in this paper. The comparison showed that the derived seabed sediments results using angular response model agree with the grab sampling results. The advantage of mapping the seabed sedimentation using multibeam backscatter data over the grab sampling method is that it can provide the seabed sediment mapping for the entire area using the MBES due to its 100% coverage of the seabed.
Mohammed El-Diasty. Mapping seabed sediments for Sharm Obhur using multibeam echosounder backscatter data. Modeling Earth Systems and Environment 2019, 6, 163 -171.
AMA StyleMohammed El-Diasty. Mapping seabed sediments for Sharm Obhur using multibeam echosounder backscatter data. Modeling Earth Systems and Environment. 2019; 6 (1):163-171.
Chicago/Turabian StyleMohammed El-Diasty. 2019. "Mapping seabed sediments for Sharm Obhur using multibeam echosounder backscatter data." Modeling Earth Systems and Environment 6, no. 1: 163-171.
Accurate bathymetric modeling is required for safe maritime navigation in shallow waters as well as for other marine operations. Traditionally, bathymetric modeling is commonly carried out using linear models, such as the Stumpf method. Linear methods are developed to derive bathymetry using the strong linear correlation between the grey values of satellite imagery visible bands and the water depth where the energy of these visible bands, received at the satellite sensor, is inversely proportional to the depth of water. However, without satisfying homogeneity of the seafloor topography, this linear method fails. The current state-of-the-art is represented by artificial neural network (ANN) models, which were developed using a non-linear, static modeling function. However, more accurate modeling can be achieved using a highly non-linear, dynamic modeling function. This paper investigates a highly non-linear wavelet network model for accurate satellite-based bathymetric modeling with dynamic non-linear wavelet activation function that has been proven to be a valuable modeling method for many applications. Freely available Level-1C satellite imagery from the Sentinel-2A satellite was employed to develop and justify the proposed wavelet network model. The top-of-atmosphere spectral reflectance values for the multispectral bands were employed to establish the wavelet network model. It is shown that the root-mean-squared (RMS) error of the developed wavelet network model was about 1.82 m, and the correlation between the wavelet network model depth estimate and “truth” nautical chart depths was about 95%, on average. To further justify the proposed model, a comparison was made among the developed, highly non-linear wavelet network method, the Stumpf log-ratio method, and the ANN method. It is concluded that the developed, highly non-linear wavelet network model is superior to the Stumpf log-ratio method by about 37% and outperforms the ANN model by about 21%, on average, on the basis of the RMS errors. Also, the accuracy of the bathymetry-derived wavelet network model was evaluated on the basis of the International Hydrographic Organization (IHO)’s standards for all survey orders. It is shown that the accuracy of the bathymetry derived from the wavelet network model does not meet the IHO’s standards for all survey orders; however, the wavelet network model can still be employed as an accurate and powerful tool for survey planning when conducting hydrographic surveys for new, shallow water areas.
Mohammed Kandil El-Emam El-Diasty. Satellite-Based Bathymetric Modeling Using a Wavelet Network Model. ISPRS International Journal of Geo-Information 2019, 8, 405 .
AMA StyleMohammed Kandil El-Emam El-Diasty. Satellite-Based Bathymetric Modeling Using a Wavelet Network Model. ISPRS International Journal of Geo-Information. 2019; 8 (9):405.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty. 2019. "Satellite-Based Bathymetric Modeling Using a Wavelet Network Model." ISPRS International Journal of Geo-Information 8, no. 9: 405.
Global navigation satellite systems (GNSS) is widely utilized in marine applications for high accuracy vertical positioning. The errors introduced to charts by the present use of traditional shore-based discrete point chart datum (CD) can become a significant part of the total vertical error and deteriorates the vertical positioning accuracy estimated by GNSS technique. Therefore, a need for developing a CD in a continuous form is essential to replace the traditional CD so that it can be transformed from/to another continuous datum such as the reference ellipsoid (WGS84). The importance of the development of CD-to-WGS84 separation model is that it can be utilized by the hydrographers to develop an accurate vertical control for hydrographic surveys applications and can be utilized by the mariners to produce an accurate dynamic electronic navigation charts (ENC). In this paper, a Saudi continuous chart datum in the Arabian Gulf area is developed to provide CD-to-WGS84 separation model. It is shown that the Saudi continuous chart datum ranges from –14.96 m to –34.64 m and can be achieved with uncertainty ranges from 0.11 m to 0.16 m. The developed CD-to-WGS84 separation model in this paper can meet many maritime applications.
Mohammed El-Diasty; Salim Al-Harbi; Spiros Pagiatakis. Development of Saudi continuous chart datum: Arabian Gulf case study. Geomatics, Natural Hazards and Risk 2019, 10, 1738 -1749.
AMA StyleMohammed El-Diasty, Salim Al-Harbi, Spiros Pagiatakis. Development of Saudi continuous chart datum: Arabian Gulf case study. Geomatics, Natural Hazards and Risk. 2019; 10 (1):1738-1749.
Chicago/Turabian StyleMohammed El-Diasty; Salim Al-Harbi; Spiros Pagiatakis. 2019. "Development of Saudi continuous chart datum: Arabian Gulf case study." Geomatics, Natural Hazards and Risk 10, no. 1: 1738-1749.
Mohammed El-Diasty; Salim Al-Harbi; Spiros Pagiatakis. Hybrid harmonic analysis and wavelet network model for sea water level prediction. Applied Ocean Research 2018, 70, 14 -21.
AMA StyleMohammed El-Diasty, Salim Al-Harbi, Spiros Pagiatakis. Hybrid harmonic analysis and wavelet network model for sea water level prediction. Applied Ocean Research. 2018; 70 ():14-21.
Chicago/Turabian StyleMohammed El-Diasty; Salim Al-Harbi; Spiros Pagiatakis. 2018. "Hybrid harmonic analysis and wavelet network model for sea water level prediction." Applied Ocean Research 70, no. : 14-21.
Open sea and inland waterways are the most widely used mode for transporting goods worldwide. It is the International Maritime Organization (IMO) that defines the requirements for position fixing equipment for a worldwide radio-navigation system, in terms of accuracy, integrity, continuity, availability and coverage for the various phases of navigation. Satellite positioning systems can contribute to meet these requirements, as well as optimize marine transportation. Marine navigation usually consists of three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with alert limit ranges from 25 m to 0.25 m. GPS positioning is widely used for many applications and is currently recognized by IMO for a future maritime navigation. With the advancement in autonomous GPS positioning techniques such as Precise Point Positioning (PPP) and with the advent of new real-time GNSS correction services such as IGS-Real-Time-Service (RTS), it is necessary to investigate the integrity of the PPP-based positioning technique along with IGS-RTS service in terms of availability and reliability for safe navigation in maritime application. This paper monitors the integrity of an autonomous real-time PPP-based GPS positioning system using the IGS real-time service (RTS) for maritime applications that require minimum availability of integrity of 99.8 % to fulfil the IMO integrity standards. To examine the integrity of the real-time IGS-RTS PPP-based technique for maritime applications, kinematic data from a dual frequency GPS receiver is collected onboard a vessel and investigated with the real-time IGS-RTS PPP-based GPS positioning technique. It is shown that the availability of integrity of the real-time IGS-RTS PPP-based GPS solution is 100 % for all navigation phases and therefore fulfil the IMO integrity standards (99.8 % availability) immediately (after 1 second), after 2 minutes and after 42 minutes of convergence time for Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking, respectively. Moreover, the misleading information is about 2 % for all navigation phases that is considered less safe is not in immediate danger because the horizontal position error is less than the navigation alert limits.
M. El-Diasty. INTEGRITY ANALYSIS OF REAL-TIME PPP TECHNIQUE WITH IGS-RTS SERVICE FOR MARITIME NAVIGATION. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2017, XLII-4/W5, 61 -66.
AMA StyleM. El-Diasty. INTEGRITY ANALYSIS OF REAL-TIME PPP TECHNIQUE WITH IGS-RTS SERVICE FOR MARITIME NAVIGATION. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2017; XLII-4/W5 ():61-66.
Chicago/Turabian StyleM. El-Diasty. 2017. "INTEGRITY ANALYSIS OF REAL-TIME PPP TECHNIQUE WITH IGS-RTS SERVICE FOR MARITIME NAVIGATION." The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W5, no. : 61-66.
A major error component of Global Positioning System (GPS) is the ionospheric delay. Ionopspheric error can be reduced by a dual frequency receiver using a linear combination technique that can not be applied with a single frequecy receiver. However, an accurate ionospheric error modeling for single-frequency receiver is required. Due to the nonlinearity of the ionospheric error, a highly nonlinear wavelet network (WN) method is proposed in this paper. The main objective of the paper is to develop a short-term prediction model based on a short dataset. Therefore, five GPS stations with five days of ionospheric datasets along with time and location were employed to develop the proposed WN-based ionospheric model. Four days of datasets were employed to develop the model and one day of dataset was employed to test the prediction accuracy. To validate the WN-based ionospheric model, a comparison was made between the developed WN-based ionospheric model and the CODE, JPL and IGS Global Ionospheric Map (GIM) models. It is shown that the Root-Mean-Squared (RMS) errors of the developed WN-based ionospheric model are 2.51 TECU, 2.75 TECU and 2.50 TECU (Total Electronic Content Unit) with percentage errors of about 3.4%, 3.8% and 3.4% when compared with the CODE, JPL and IGS GIM models.
Mohammed Kandil El-Emam El-Diasty. Regional ionospheric modeling using wavelet network model. The Journal of Global Positioning Systems 2017, 15, 2 .
AMA StyleMohammed Kandil El-Emam El-Diasty. Regional ionospheric modeling using wavelet network model. The Journal of Global Positioning Systems. 2017; 15 (1):2.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty. 2017. "Regional ionospheric modeling using wavelet network model." The Journal of Global Positioning Systems 15, no. 1: 2.
Accurate water levels modelling and prediction is essential for maritime applications. Water prediction is traditionally developed using the least-squares-based harmonic analysis method based on water level change (WLC) measurements. If long water level measurements are not obtained from the tide gauge, accurate water levels prediction cannot be estimated. To overcome the above limitations, the wavelet neural network (WNN) has recently been developed for the WLC prediction from short water level measurements. However, a new adaptive neuro-fuzzy inference system (ANFIS) model is proposed and developed in this paper. The ANFIS model is utilized to predict and select the WLC models of one month of hourly WLC for Yarmouth, Sain-John and Charlottetown stations in Canadian waters and compared with the current-state-of-the-art WNN model. The statistical analysis is applied to analyse the performance of the developed model in training and testing stages. The results showed an accurate modelling level using ANFIS technique for each station in training and testing stage. A comparison between the developed ANFIS method and the current-state-of-the-art WNN method shows that the accuracy of the developed ANFIS model is superior to the current-state-of-the-art model by 21.5% in average.
Mosbeh R Kaloop; Mohammed El-Diasty; Jong Wan Hu. Real-time prediction of water level change using adaptive neuro-fuzzy inference system. Geomatics, Natural Hazards and Risk 2017, 8, 1320 -1332.
AMA StyleMosbeh R Kaloop, Mohammed El-Diasty, Jong Wan Hu. Real-time prediction of water level change using adaptive neuro-fuzzy inference system. Geomatics, Natural Hazards and Risk. 2017; 8 (2):1320-1332.
Chicago/Turabian StyleMosbeh R Kaloop; Mohammed El-Diasty; Jong Wan Hu. 2017. "Real-time prediction of water level change using adaptive neuro-fuzzy inference system." Geomatics, Natural Hazards and Risk 8, no. 2: 1320-1332.
The multibeam echosounding technique is used to provide seafloor mapping at a relatively high-quality level and requires an accurate positioning and orientation system. Integration of a global positioning system (GPS) and an inertial navigation system (INS) is widely used for positioning and orientation control and is performed by using an inertial unit integrated with a real-time kinematic (RTK) GPS solution with two GPS receivers to provide the required accuracy. However, the RTK-based GPS/INS system is presently limited to a distance of approximately 10 km and cannot be used for offshore hydrographic surveys. Recently, precise-point positioning (PPP) technology has shown promise toward the development of an autonomous GPS solution for positioning applications in which only one GPS receiver is used. This paper investigates a real-time PPP-based GPS/INS integrated system position and orientation solution using the international GPS service (IGS) real-time service (RTS) for hydrographic surveys. To meet this objective, the real-time IGS-RTS PPP-based GPS solution is integrated with the INS solution. It is shown that the real-time IGS-RTS PPP-based GPS/INS integration system fulfills International Hydrographic Organization (IHO) special-order 1a, 1b, and 2 requirements at the 95% confidence level and can be used for onshore and offshore hydrographic surveys.
Mohammed El-Diasty. Development of Real-Time PPP-Based GPS/INS Integration System Using IGS Real-Time Service for Hydrographic Surveys. Journal of Surveying Engineering 2016, 142, 05015005 .
AMA StyleMohammed El-Diasty. Development of Real-Time PPP-Based GPS/INS Integration System Using IGS Real-Time Service for Hydrographic Surveys. Journal of Surveying Engineering. 2016; 142 (2):05015005.
Chicago/Turabian StyleMohammed El-Diasty. 2016. "Development of Real-Time PPP-Based GPS/INS Integration System Using IGS Real-Time Service for Hydrographic Surveys." Journal of Surveying Engineering 142, no. 2: 05015005.
In this paper, new perspectives and developments in applying a ground-based micro-gravimetric method to detect groundwater storage change in Waterloo Moraine are investigated. Four epochs of gravity survey were conducted using absolute gravimeter (FG5), two relative gravity meters (CG5) and two geodetic global positioning systems (GPS) in the Waterloo Moraine in May and August of 2010 and 2011, respectively. Data were processed using the parametric least-squares method and integrated with geological and hydrological studies. The gravity differences between May and August for 2010 and 2011 epochs were inverted to provide the estimated total water storage changes. Changes in soil water content obtained from land surface models of Ecological Assimilation of Land and Climate Observations (EALCO) and the Global Land Data Assimilation System (GLDAS) program were employed to estimate the groundwater storage change. The ratios between the estimated groundwater storage changes and measured water table changes (specific yields) were determined at a local monitoring well located in the survey area. The results showed that the estimates of specific yields between May and August of 2010 and 2011 were consistent at a significant confidence level and are also within the range of the specific yield from geological and hydrological studies. Therefore, the micro-gravimetric (absolute and relative gravity meters) technology has demonstrated the great potential in detecting groundwater storage change and specific yield for local scale aquifers such as Waterloo Moraine.
Mohammed El-Diasty. Groundwater storage change detection using micro-gravimetric technology. Journal of Geophysics and Engineering 2016, 13, 259 -272.
AMA StyleMohammed El-Diasty. Groundwater storage change detection using micro-gravimetric technology. Journal of Geophysics and Engineering. 2016; 13 (3):259-272.
Chicago/Turabian StyleMohammed El-Diasty. 2016. "Groundwater storage change detection using micro-gravimetric technology." Journal of Geophysics and Engineering 13, no. 3: 259-272.
The integration of Global Positioning System (GPS) with Inertial Navigation System (INS) has been widely used in many applications for positioning and orientation purposes. Traditionally, random walk (RW), Gauss-Markov (GM), and autoregressive (AR) processes have been used to develop the stochastic model in classical Kalman filters. The main disadvantage of classical Kalman filter is the potentially unstable linearization of the nonlinear dynamic system. Consequently, a nonlinear stochastic model is not optimal in derivative-based filters due to the expected linearization error. With a derivativeless-based filter such as the unscented Kalman filter or the divided difference filter, the filtering process of a complicated highly nonlinear dynamic system is possible without linearization error. This paper develops a novel nonlinear stochastic model for inertial sensor error using a wavelet network (WN). A wavelet network is a highly nonlinear model, which has recently been introduced as a powerful tool for modelling and prediction. Static and kinematic data sets are collected using a MEMS-based IMU (DQI-100) to develop the stochastic model in the static mode and then implement it in the kinematic mode. The derivativeless-based filtering method using GM, AR, and the proposed WNbased processes are used to validate the new model. It is shown that the first-order WN-based nonlinear stochastic model gives superior positioning results to the first-order GM and AR models with an overall improvement of 30% when 30 and 60 seconds GPS outages are introduced.
Mohammed Kandil El-Emam El-Diasty; Ahmed El-Rabbany; Spiros Pagiatakis. An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks. nano Online 2016, 1 .
AMA StyleMohammed Kandil El-Emam El-Diasty, Ahmed El-Rabbany, Spiros Pagiatakis. An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks. nano Online. 2016; ():1.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty; Ahmed El-Rabbany; Spiros Pagiatakis. 2016. "An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks." nano Online , no. : 1.
Mohammed El-Diasty; Salim Al-Harbi. Development of wavelet network model for accurate water levels prediction with meteorological effects. Applied Ocean Research 2015, 53, 228 -235.
AMA StyleMohammed El-Diasty, Salim Al-Harbi. Development of wavelet network model for accurate water levels prediction with meteorological effects. Applied Ocean Research. 2015; 53 ():228-235.
Chicago/Turabian StyleMohammed El-Diasty; Salim Al-Harbi. 2015. "Development of wavelet network model for accurate water levels prediction with meteorological effects." Applied Ocean Research 53, no. : 228-235.
The maritime navigation accuracy requirements for radionavigation systems such as GPS are specified by the International Maritime Organization (IMO). Maritime navigation usually consists of three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with an accuracy requirement that ranges from 10 m to 0.1 m. With the advancement in autonomous GPS positioning techniques such as Precise Point Positioning (PPP) and with the advent of the new IGS-Real-Time-Service (RTS), it is necessary to assess the possibility of a wider role of the PPP-based positioning technique in maritime applications. This paper investigates the performance of an autonomous real-time PPP-positioning solution by using the IGS- RTS service for maritime applications that require an accurate positioning system. To examine the performance of the real-time IGS-RTS PPP-based technique for maritime applications, kinematic data from a dual frequency GPS receiver is investigated. It is shown that the real-time IGS-RTS PPP-based GPS positioning technique fulfills IMO requirements for maritime applications with an accuracy requirement ranges from 10 m for Ocean/Coastal/Port approach/Inland waterways navigation to 1.0 m for in port navigation but cannot fulfill the automatic docking application with an accuracy requirement of 0.10 m. To further investigate the real-time PPP-based GPS positioning technique, a comparison is made between the real-time IGS-RTS PPP-based positioning technique and the real-time PPP-based positioning by using the predicted part of the IGS Ultra-Rapid products and the real-time GPS positioning technique with the Wide Area Differential GPS service (WADGPS). It is shown that the IGS-RTS PPP-based positioning technique is superior to the IGS-Ultra-Rapid PPP-based and WADGPS-based positioning techniques.
Mohammed El-Diasty; Mohamed Elsobeiey. Precise Point Positioning Technique with IGS Real-Time Service (RTS) for Maritime Applications. Positioning 2015, 06, 71 -80.
AMA StyleMohammed El-Diasty, Mohamed Elsobeiey. Precise Point Positioning Technique with IGS Real-Time Service (RTS) for Maritime Applications. Positioning. 2015; 06 (04):71-80.
Chicago/Turabian StyleMohammed El-Diasty; Mohamed Elsobeiey. 2015. "Precise Point Positioning Technique with IGS Real-Time Service (RTS) for Maritime Applications." Positioning 06, no. 04: 71-80.
We develop a new frequency-domain dynamic response method to model integrated Inertial Navigation System (INS) and Global Positioning System (GPS) architectures and provide an accurate impulse-response-based INS-only navigation solution when GPS signals are denied (GPS outages). The input to such a dynamic system is the INS-only solution and the output is the INS/GPS integration solution; both are used to derive the transfer function of the dynamic system using Least Squares Frequency Transform (LSFT). The discrete Inverse Least Squares Frequency Transform (ILSFT) of the transfer function is applied to estimate the impulse response of the INS/GPS system in the time domain. It is shown that the long-term motion dynamics of a DQI-100 IMU/Trimble BD950 integrated system are recovered by 72%, 42%, 75%, and 40% for north and east velocities, and north and east positions respectively, when compared with the INS-only solution (prediction mode of the INS/GPS filter). A comparison between our impulse response model and the current state-of-the-art time-domain feed-forward neural network shows that the proposed frequency-dependent INS/GPS response model is superior to the neural network model by about 26% for 2D velocities and positions during GPS outages.
Mohammed El-Diasty; Spiros Pagiatakis. A Frequency-Domain INS/GPS Dynamic Response Method for Bridging GPS Outages. Journal of Navigation 2010, 63, 627 -643.
AMA StyleMohammed El-Diasty, Spiros Pagiatakis. A Frequency-Domain INS/GPS Dynamic Response Method for Bridging GPS Outages. Journal of Navigation. 2010; 63 (4):627-643.
Chicago/Turabian StyleMohammed El-Diasty; Spiros Pagiatakis. 2010. "A Frequency-Domain INS/GPS Dynamic Response Method for Bridging GPS Outages." Journal of Navigation 63, no. 4: 627-643.
In this paper, we examine the effect of changing the temperature points on MEMS-based inertial sensor random error. We collect static data under different temperature points using a MEMS-based inertial sensor mounted inside a thermal chamber. Rigorous stochastic models, namely Autoregressive-based Gauss-Markov (AR-based GM) models are developed to describe the random error behaviour. The proposed AR-based GM model is initially applied to short stationary inertial data to develop the stochastic model parameters (correlation times). It is shown that the stochastic model parameters of a MEMS-based inertial unit, namely the ADIS16364, are temperature dependent. In addition, field kinematic test data collected at about 17 °C are used to test the performance of the stochastic models at different temperature points in the filtering stage using Unscented Kalman Filter (UKF). It is shown that the stochastic model developed at 20 °C provides a more accurate inertial navigation solution than the ones obtained from the stochastic models developed at −40 °C, −20 °C, 0 °C, +40 °C, and +60 °C. The temperature dependence of the stochastic model is significant and should be considered at all times to obtain optimal navigation solution for MEMS-based INS/GPS integration.
Mohammed Kandil El-Emam El-Diasty; Spiros Pagiatakis. A Rigorous Temperature-Dependent Stochastic Modelling and Testing for MEMS-Based Inertial Sensor Errors. Sensors 2009, 9, 8473 -8489.
AMA StyleMohammed Kandil El-Emam El-Diasty, Spiros Pagiatakis. A Rigorous Temperature-Dependent Stochastic Modelling and Testing for MEMS-Based Inertial Sensor Errors. Sensors. 2009; 9 (11):8473-8489.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty; Spiros Pagiatakis. 2009. "A Rigorous Temperature-Dependent Stochastic Modelling and Testing for MEMS-Based Inertial Sensor Errors." Sensors 9, no. 11: 8473-8489.
The integration of Inertial Navigation System (INS) and Global Positioning System (GPS) architectures can be achieved through the use of many time-domain filters such as, extended Kalman, unscented Kalman, divided difference, and particle filters. The main objective of these filters is to achieve precise fusion of the data from GPS and INS to provide INS-only navigation solution during GPS outages. The prediction mode performance of all state-of-the-art time-domain filters is poor with significant drift in the INS-only solution. In this paper, a new frequency-domain dynamic response method is proposed to model the INS/GPS system. The input to this dynamic system is the INS-only solution and the output is the INS/GPS integration solution that help derive the transfer function. The discrete Inverse Least Squares Frequency Transform (ILSFT) of the transfer function is applied to estimate the impulse response of the INS/GPS system. It is shown that the long-term motion dynamics are recovered by 72%, 42%, 75%, and 40% for north velocities, east velocities, north positions, and east positions respectively when compared with INS-only solution (prediction mode of the INS/GPS filter).
Mohammed El-Diasty; Spiros Pagiatakis. An efficient INS/GPS impulse response model for bridging GPS outages. 2009 IEEE Toronto International Conference Science and Technology for Humanity (TIC-STH) 2009, 328 -333.
AMA StyleMohammed El-Diasty, Spiros Pagiatakis. An efficient INS/GPS impulse response model for bridging GPS outages. 2009 IEEE Toronto International Conference Science and Technology for Humanity (TIC-STH). 2009; ():328-333.
Chicago/Turabian StyleMohammed El-Diasty; Spiros Pagiatakis. 2009. "An efficient INS/GPS impulse response model for bridging GPS outages." 2009 IEEE Toronto International Conference Science and Technology for Humanity (TIC-STH) , no. : 328-333.
Mohammed Kandil El-Emam El-Diasty; A El-Rabbany; S Pagiatakis. Temperature variation effects on stochastic characteristics for low-cost MEMS-based inertial sensor error. Measurement Science and Technology 2007, 18, 3321 -3328.
AMA StyleMohammed Kandil El-Emam El-Diasty, A El-Rabbany, S Pagiatakis. Temperature variation effects on stochastic characteristics for low-cost MEMS-based inertial sensor error. Measurement Science and Technology. 2007; 18 (11):3321-3328.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty; A El-Rabbany; S Pagiatakis. 2007. "Temperature variation effects on stochastic characteristics for low-cost MEMS-based inertial sensor error." Measurement Science and Technology 18, no. 11: 3321-3328.
Mohammed Kandil El-Emam El-Diasty; Ahmed El-Rabbany; Spiros Pagiatakis. An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks. Journal of Applied Geodesy 2007, 1, 1 .
AMA StyleMohammed Kandil El-Emam El-Diasty, Ahmed El-Rabbany, Spiros Pagiatakis. An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks. Journal of Applied Geodesy. 2007; 1 (4):1.
Chicago/Turabian StyleMohammed Kandil El-Emam El-Diasty; Ahmed El-Rabbany; Spiros Pagiatakis. 2007. "An accurate nonlinear stochastic model for MEMS-based inertial sensor error with wavelet networks." Journal of Applied Geodesy 1, no. 4: 1.