Derivation of high-resolution orthophoto map from multirotor drone survey for application in infrastructure management

An orthophoto is a geometrically corrected aerial image that can be used in the same approach as map. It provides various geospatial information and therefore plays an important role in infrastructure management. This paper describes the methodology of an aerial survey using a multirotor drone and the processing of aerial images acquired from the survey to produce an orthophoto map. The survey work was carried out using Zenmuse X4S photogrammetric camera controlled by an autopilot multirotor drone at 200m above the ground. Optimal flight path for the autonomous mission was created and organized using the Map Pilot software. Five ground control points were laid within the survey area and their locations were determined using a real-time kinematic global navigation satellite system. Aerial images acquired from the survey were processed with the Pix4Dmapper photogrammetry software. The photogrammetric processing generated a 6 cm-resolution orthophoto map. The presented work demonstrates the practicality of multirotor drone survey and intelligent image processing for non-professionals in deriving high-resolution orthophoto map for application in infrastructure management

Granite Exploration by using Electrical Resistivity Imaging (ERI): A Case Study in Johor

Electrical Resistivity Imaging (ERI) is a tool used in near surface geophysical surveys by flowing an electric current through electrodes that were injected into the ground. The usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in geotechnical engineering application owing to the efficiency and effectiveness of the method in term of time, cost and also data coverage. The survey performed with respect to the particular reference to ERI in determining the granite rock underneath the ground. There were seven (7) lines of ERI performed at the study area by using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Six (6) boreholes were also drilled to obtain engineering properties of rock at the study area. In order to develop the relationship between resistivity and engineering properties, a comparison between borehole field test result and the resistivity value were made. Results from the ERT indicated the presence of zones with high resistivity values identified as overburden soil, fractured granite and solid granite. The findings of this study also showed that the electrical resistivity imaging coupled with borehole drillings were applicable tools for the determination of the granite rock underneath the ground via subsurface profiles and such as depth of overburden soil and engineering properties of soil

Application of unmanned aerial vehicle (UAV) for slope mapping at Pahang Matriculation College, Malaysia

This paper discusses the applications of unmanned aerial vehicle (UAV) for slope mapping which located at Pahang Matriculation College, Malaysia. Mapping is very important to obtain the terrain profiles for study area. By using UAV and commercial software, important information of slopes including perimeter, area and volume will be determined. With the development of modern technology, the utilization of UAV to gather data for mapping becoming easier as it is quick, reliable, precise, cost-effective and also easily to operate. High imagery quality is essential for the effectiveness and nature of normal mapping output such as Digital Surface Model (DSM) and Digital Orthophoto. With the help of established software, the dimensions of selected study area can be determined easily which can be considered as the main interest in this study. In addition to that, the cross-section of selected area can be obtained which help to determine the highest and lowest point of each area together with the terrain profiles. These slope profiles are determined according to their respective axis (vertical and horizontal) since both axis give different terrain profiles for each slope. Other than that, this research was further extended by determining the potential slope hazard based on their respective angles. These determinations are very important as early precautionary steps for engineers and researchers to prevent from any danger, injuries and accidents that for worse may cause fatalities

Application of Unmanned Aerial Vehicle (UAV) for Slope Mapping at Pahang Matriculation College, Malaysia

This paper discusses the applications of unmanned aerial vehicle (UAV) for slope mapping which located at Pahang Matriculation College, Malaysia. Mapping is very important to obtain the terrain profiles for study area. By using UAV and commercial software, important information of slopes including perimeter, area and volume will be determined. With the development of modern technology, the utilization of UAV to gather data for mapping becoming easier as it is quick, reliable, precise, cost-effective and also easily to operate. High imagery quality is essential for the effectiveness and nature of normal mapping output such as Digital Surface Model (DSM) and Digital Orthophoto. With the help of established software, the dimensions of selected study area can be determined easily which can be considered as the main interest in this study. In addition to that, the cross-section of selected area can be obtained which help to determine the highest and lowest point of each area together with the terrain profiles. These slope profiles are determined according to their respective axis (vertical and horizontal) since both axis give different terrain profiles for each slope. Other than that, this research was further extended by determining the potential slope hazard based on their respective angles. These determinations are very important as early precautionary steps for engineers and researchers to prevent from any danger, injuries and accidents that for worse may cause fatalities

Granite exploration by using electrical resistivity imaging (ERI): a case study in Johor

Electrical Resistivity Imaging (ERI) is a tool used in near surface geophysical surveys by flowing an electric current through electrodes that were injected into the ground. The usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in geotechnical engineering application owing to the efficiency and effectiveness of the method in term of time, cost and also data coverage. The survey performed with respect to the particular reference to ERI in determining the granite rock underneath the ground. There were seven (7) lines of ERI performed at the study area by using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Six (6) boreholes were also drilled to obtain engineering properties of rock at the study area. In order to develop the relationship between resistivity and engineering properties, a comparison between borehole field test result and the resistivity value were made. Results from the ERI indicated the presence of zones with high resistivity values identified as overburden soil, fractured granite and solid granite. The findings of this study also showed that the electrical resistivity imaging coupled with borehole drillings were applicable tools for the determination of the granite rock underneath the ground via subsurface profiles and such as depth of overburden soil and engineering properties of soil. In conclusion, ERI is a method that does not disturb the structure or the function of the soil which successfully became the best method in exploring the granite rock