Yazar "Bayrak, Temel" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • Küçük Resim
    Öğe
    Application of Low-Cost GPS Tools and Techniques for Landslide Monitoring: A Review
    (Jurnal Teknologi, 2014) Etim, E. Eyo; Musa, Tajul Ariffin; Omar, Kamaludin Mohd; Idris, Khairulnizam M.; Bayrak, Temel; Onuigbo, Ifeanyi; Opaluwa, Yusuf
    The main goal of our ongoing research is to design a low-cost continuous monitoring system for landslide investigation using the Reverse RTK (RRTK) technique. The main objectives of this paper are to review the existing Global Positioning System (GPS) tools and techniques used for landslide monitoring, and to propose a novel low-cost landslide monitoring technique using Reverse RTK GPS. A general overview of GPS application in landslide monitoring is presented, followed by a review of GPS deformation monitoring systems and some of the factors used for their categorization. Finally, the concept, principles and advantages of the proposed new landslide monitoring system are discussed.
  • [ X ]
    Öğe
    Deformation Analysis Based on Designed Experiments and Kalman Filter
    (Croatian Geodetic Soc, 2014) Eyo, Etim; Bayrak, Temel; Musa, Tajul; Onuigbo, Ifeanyi; Kuta, Abdullahi; Odumosu, Joseph
    This paper is focused on the deformation monitoring of survey control points in the Gidan Kwano main campus, Federal University of Technology, Minna, Nigeria. The main objectives are to develop and test a kinematic deformation analysis model using simulated GPS test data. RTK GPS was the main equipment deployed for the monitoring. The kinematic deformation analysis model developed for this study was based on Kalman filtering technique. In order to verify the developed kinematic model, designed experiments, with artificially introduced deformations, were performed to test centimetre-level horizontal movements on four points (GPS 01, GPS 08, GPS 09 and GPS 12). The developed kinematic model was used to determine six unknown parameters of movements, namely position displacements (dx, dy), velocities (Vx, Vy) and accelerations (ax, ay). The results of the computed movement parameters of the control points show that the introduced deformations were detected by the kinematic deformation model. The model also detected that there was no deformation introduced to point GPS 09. Some of the discrepancies in the computed results can be attributed to centring errors during observations.
  • [ X ]
    Öğe
    DEVELOPMENT OF AN ALTERNATIVE LOW-COST LANDSLIDE MONITORING METHOD USING DATA FROM TUSAGA-AKTIF GNSS NETWORK
    (Univ Federal Parana, Centro Politecnico, 2015) Bayrak, Temel; Eyo, Etim; Basoglu, Nesat; Musa, Tajul; Akpee, Dinebari
    The main objectives of this paper are to develop a kinematic deformation analysis model for landslides using Kalman filtering procedures; and to utilise the observations from TUSAGA-Aktif GNSS Network in Turkey to determine the velocity fields of a landslide study area in the Eastern Black Sea Region of Turkey. Thirty five (35) points were established for the determination of 3D time dependent velocities of the landslides study area. Point displacements and velocities were determined by single point kinematic model to perform 3-D statistical analysis, and to assess the significance of point displacements and velocities using three periodic observations from TUSAGA-Aktif Network. The determined velocities were used to generate the velocity fields of the landslide area for three epochs using Geographic Information System (GIS). The results obtained indicate that almost all the monitored points showed significant movements, with varying magnitudes of velocities. The directions of movement of the 35 monitored points were also determined. The results show that the dominant trends of landslide movements in the study area are in the northwest and northeast directions. These results are in agreement with the previous results obtained in the same study area about ten years ago.
  • Küçük Resim
    Öğe
    Global Positioning System Network Reference Control Optimization Using Dilution of Precision Variances in Gidan Kwano Area, Minna, Nigeria
    (International Journal of Scientific and Engineering Research, 2014) Lazarus, M. Ojigi; Etim, E. Eyo; Bayrak, Temel
    The precision of Global Positioning System (GPS) observables depends on the satellite geometry, represented by the Dilution of Precision (DOP) values, and range of errors caused by signal strength, ionospheric delay, tropospheric delay, and satellite clock offset from GPS time, multipath effects, receiver antenna phase shift, etc. One of the ways of assessing the integrity of satellite availability, positional and navigational accuracy of GPS observation is the use of dilution of precision (DOP) during field observations. This study therefore attempts to optimize GPS Network Reference Control in Gidan Kwano area of Minna, Nigeria, using pre-observation planning and post-observation DOP variances, for selecting the optimum reference point within an established survey network, for future observations and control extension in the study area. Twenty-five (25) GPS stations were observed in rapid-static mode with Leica SR20 DGPS Receivers. The estimates of the DOPs (GDOP, PDOP, HDOP, VDOP and TDOP) showed that, post-observation DOPs have mean values of 2.0, 1.8, 1.6, 0.9, and 0.9 for GDOP, PDOP, HDOP, VDOP and TDOP, respectively, which agree with the post-observation DOPs within about 80 -90%. This implies that, the PDOP developed in the pre-observation planning is valid for rapid-static or kinematic surveys in the study area but less valid for a long-duration (30-minutes and above) static survey in the study area. Based on the DOPs variance analysis for each observed network point, control point GPS14 with PDOP and GDOP of 1.4 and 1.5, respectively was adjudged the optimum point as Reference for survey network observations and extension in the study area.
  • [ X ]
    Öğe
    Kinematic Analysis of Small and Slow-Moving Landslides Using Pleiades-1 Satellite Data
    (Ieee-Inst Electrical Electronics Engineers Inc, 2023) Eyo, Etim; Hashim, Mazlan; Reba, Mohd Nadzri Md; Bayrak, Temel; Shahabi, Himan
    Although they may have small velocity values, small slope failures can cause damage to facilities such as roads and pipelines. The main goals of this paper are to detect and map, and quantify the kinematics of small and slow-moving landslides in Kutlugun, Northeastern Turkey. Object-based image analysis (OBIA) and rule-based classification techniques were utilized to detect and map the small and slow-moving landslides. The horizontal displacement of the landslides was investigated using the sub-pixel image correlation method, Cosi-Corr software, and Pleiades-1 images. Kalman filtering method and Real-Time Kinematics-Global Positioning System (RTK-GPS) observations were utilized to formulate a kinematic analysis model for the landslides. A total of 123 small landslides covering an area of approximately 413.332 m(2) were detected in the study area. The displacements determined by image correlation compare very well with the RTK-GPS measurements, with a maximum deviation of 0.86 mm. The movement rate of the small landslide from RTK-GPS results ranged from 0.80- 8.28 mm during the six-month monitoring period. The average displacement value for all the monitoring points is 9.88 mm, while the average movement rate is 3.11 mm during the monitoring period. Compared to the deformation obtained using only the RTK-GPS measurements, the optical image correlation produced a more coherent deformation pattern and more detailed information on the extent and distribution of deformation. The results of the kinematic analysis suggest that the entire body of the small landslide moved slowly during the monitoring period.
  • Küçük Resim
    Öğe
    Modelling the relationship between water level and vertical displacements on the Yamula Dam, Turkey
    (Natural Hazards and Earth System Sciences, 2007) Bayrak, Temel
    Monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the study is to find the extent to which rising reservoir level affects the mechanism of deformation of The Yamula Dam under certain change in the reservoir level conditions during to the first filling period. Three different deformation analysis techniques, namely static, kinematic and dynamic, were used to analyze four geodetic monitoring records consisting of vertical displacements of nine object points established on the Dam and six reference points surrounding of it, to see whether the rising reservoir level have a role in the vertical deformations during the first filling period. The largest vertical displacements were in the middle of the dam. There is an apparent linear relationship between the dam subsidence and the reser- voir level. A dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the ob- served structural deformation of the dam.
  • Küçük Resim
    Öğe
    Verifying Pressure of Water on Dams, a Case Study
    (Sensors, 2008) Bayrak, Temel
    Sensing and monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the present study is to find the extent to which rising reservoir level affects the mechanism of deformation of the Yamula dam under certain changes in the reservoir level conditions during the first filling period. A new dynamic deformation analysis technique was developed to analyze four geodetic monitoring records consisting of vertical and horizontal displacements of nine object points established on the dam and six reference points surrounding it, to see whether the rising reservoir level is responsible for the vertical and horizontal deformations during the first filling period. The largest displacements were determined in the middle points of the dam construction. There is an apparent linear relationship between the dam subsidence and the reservoir level. The dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the observed structural deformation of the dam.