Papers by Mohamed Aissa Meslem
The use of GPS for the estimation of orthometric heights in a given region, with the help of exis... more The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can be collected swiftly without using the orthometric heights from levelling; it is what one calls commonly levelling by GPS. In this framework, the Least Squares Collocation method (LSC) has been used to evaluate the quality of the available GPS-Levelling data, to determine a gravimetric geoid in the North region of Algeria and to estimate the constant datum bias. The data used in the setting of this study are: The geopotential model EGM96, a total number of 2534 gravity anomalies, as well as 43 GPS points connected to the geodetic network levelling present on the whole North part of Algerian.
Supplementary material to "Coastal Sea Level Monitoring in the Mediterranean and Black Seas
Power-law noise Identification: Application in Timing
Campaign for the Selection of Sites Eligible for Installation of GNSS / Cors Stations in Algeria: Study and Analysis
SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings, 2019
A nationwide project is under taken since a few years with the purpose to upgrade the geodetic in... more A nationwide project is under taken since a few years with the purpose to upgrade the geodetic infrastructure by setting up a wide real-time GNSS/CORS (Global Navigation Satellite System/Continuously Operating Reference Stations) network. In this perspective, a study is achieved in the setting of this assignment with the purpose to select eligible sites of the network infrastructure. The technical selection criteria were based essentially on the assessment of GNSS data received by permanent sites under experiment. Northern and southern GNSS sites over the territory has been selected to perform this investigation. These sites are located in Algiers (DZAL), Oran (DZOR) and Constantine (DZCO) in the north and in Ouargla (OGLA), Bechar (BECH) and Tindouf (TIND) in the south. The study is based on evaluation of monument stability analysis through the post-processing of data supplied by these GNSS sites, multipath and signal interference evaluation. Finally, we analyzed the Vertical Total Electron Content (VTEC) variations in the aim to confirm a previous result in term of ionosphere response at low latitude.
Spanning over a century, a traditional way to monitor sea level variability by tide gauges isin c... more Spanning over a century, a traditional way to monitor sea level variability by tide gauges isin combination with modern observational techniques like satellite altimetryan inevitable ingredient in sea level studies over the climate scales and in coastal seas. The development of the instrumentation, remote data acquisition, processing and archiving in last decades allowed for extending the applications towards a variety of users and coastal hazard managers. The Mediterranean and Black seas are an example for such a transitionwhile having a long tradition for sea level observations with several records spanning over a century, the number of modern tide gauge stations are growing rapidly, with data available both in real-time and as a research product at different time resolutions. As no comprehensive survey of the tide gauge networks has been carried out recently in these basins, the aim of this paper is to map the existing coastal sea level monitoring infrastructures and the respective data availability. The survey encompasses description of major monitoring networks in the Mediterranean and Black seas and their characteristics, including the type of sea level sensors, measuring resolutions, data availability and existence of ancillary measurements, altogether collecting information about 236 presently operational tide gauge stations. The availability of the Mediterranean and Black seas sea level data in the global and European sea level repositories has been also screened and classified following their sampling interval and level of quality-check, pointing to the necessity of harmonization of the data available with different metadata and series at different repositories. Finally, an assessment of the networks' capabilities for their usage in different sea level applications has been done, with recommendations that might mitigate the bottlenecks and assure further development of the networks in a coordinated way, being that more necessary in the era of the human-induced climate changes and the sea level rise.
The use of GPS for the estimation of orthometric heights in a given region, with the help of exis... more The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can be collected swiftly without using the orthometric heights from levelling; it is what one calls commonly levelling by GPS. In this framework, the Least Squares Collocation method (LSC) has been used to evaluate the quality of the available GPS-Levelling data, to determine a gravimetric geoid in the North region of Algeria and to estimate the constant datum bias. The data used in the setting of this study are: The geopotential model EGM96, a total number of 2534 gravity anomalies, as well as 43 GPS points connected to the geodetic network levelling present on the whole North part of Algerian.
A gravimetric quasi-geoid evaluation in the Northern region of Algeria using EGM96 and GPS/Levelling
Newton S Bulletin, 2006
The use of GPS for the estimation of orthometric heights in a given region, with the help of exis... more The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can
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The use of GPS for the estimation of orthometric heights in a given region, with the help of exis... more The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can be collected swiftly without using the orthometric heights from levelling; it is what one calls commonly levelling by GPS.
Conference Presentations by Mohamed Aissa Meslem
International Multidisciplinary Scientific GeoConference: SGEM, 2019
A nationwide project is under taken since a few years with the purpose to upgrade the geodetic in... more A nationwide project is under taken since a few years with the purpose to upgrade the geodetic infrastructure by setting up a wide real-time GNSS/CORS (Global Navigation Satellite System/Continuously Operating Reference Stations) network. In this perspective, a study is achieved in the setting of this assignment with the purpose to select eligible sites of the network infrastructure. The technical selection criteria were based essentially on the assessment of GNSS data received by permanent sites under experiment. Northern and southern GNSS sites over the territory has been selected to perform this investigation. These sites are located in Algiers (DZAL), Oran (DZOR) and Constantine (DZCO) in the north and in Ouargla (OGLA), Bechar (BECH) and Tindouf (TIND) in the south. The study is based on evaluation of monument stability analysis through the post-processing of data supplied by these GNSS sites, multipath and signal interference evaluation. Finally, we analyzed the Vertical Total Electron Content (VTEC) variations in the aim to confirm a previous result in term of ionosphere response at low latitude.
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Papers by Mohamed Aissa Meslem
Conference Presentations by Mohamed Aissa Meslem