Khairul Tahar - Academia.edu (original) (raw)

Papers by Khairul Tahar

Malaysian Journal of Society and Space

Pothole's defect is major damages indicated the road condition visually, and the structural defec... more Pothole's defect is major damages indicated the road condition visually, and the structural defects due to some potential causes. Nowadays, new forms of remote sensing technique were widely used, but less studies in the application of low altitude multispectral mapping. The potential of multispectral images is its help better in resolution due to its spectral characteristic. Hence, it helps a lot in feature classification with proper training sample, classifier used, and spectral band composite. Thus, this study aims to extract the defective roads by using the multispectral image of Parrot Sequoia with low flight altitude. This study tries to detect a pothole's existence from band combination and supervised classification other than its common use which ultimately for agriculture purposes. The classifier used in this is Maximum Likelihood, Support vector machine (SVM) and Mahalanobis Distance. 15 different probability of band stacks of green, NIR, red edge, and red band were used as multispectral images. The comparison of the performance between the types of classifier and band combination was modeled and discussed in this study. Classifier algorithm maximum likelihood gives the lowest error of 0.108m² with a combination of NIR + red edge band. SVM gives the lowest error of 0.427m² with a combination of green + NIR + red edge + red band. While Mahalanobis distance gives the lowest error of-0.082m² with a combination of red edge + red band. Averagely, Mahalanobis distance gives the lowest error of 0.299m² of all bands used.

International Journal of Electrical and Computer Engineering (IJECE)

At the current stage, an investigation technique on the accident takes a longer time and this cau... more At the current stage, an investigation technique on the accident takes a longer time and this causes longer traffic congestion. The aim of this study is to reconstruct a 3D model of an accident scene using an unmanned aerial vehicle (UAV). The flight parameters that have been chosen are the circular method, the double grid method, and the single grid method. All these designs can produce a good 3D model to achieve the study’s objective. The methodology in this study is divided into 4 phases which are preliminary work, data acquisition, data processing, and data analysis. The main results of this study are the 3D model of the accident scene, an orthophoto map layout, and an accuracy assessment of a 3D model of reconstructed accident scene. All these parameters will be tested on accuracy based on the root mean square error (RMSE) value, comparing the UAV data and site measurement data. This objective has been tested for 10 different types of processing and different types of flight pa...

IOP Conference Series: Earth and Environmental Science, 2021

Unmanned Aerial Vehicles (UAVs) are aircrafts without pilot on board, which are controlled by the... more Unmanned Aerial Vehicles (UAVs) are aircrafts without pilot on board, which are controlled by the ground station or transmitter. The ability of UAVs to provide high-resolution imageries and accurate positioning makes it the best platform as compared to satellite images. Therefore, UAVs can speed up the topographic works, especially during data collection. Topographic mapping has been used by many agencies such as the government, private, and military. Furthermore, the geotagged high resolution UAV images can provide accurate results using Ground Control Points (GCPs). UAV flight parameters, such as flight altitude and overlap and sidelap percentages, can affect the topographic map result derived from the UAV images. The optimal flight altitude and overlap and sidelap percentages based on the specific topographic surface need to be investigated to produce an accurate topographic map. The aim of this study is to assess the accuracy of topographic maps from different flight parameters....

Engineering, Technology & Applied Science Research, 2021

Unmanned Aerial Vehicles (UAVs) are increasingly used in forestry as they are economical and flex... more Unmanned Aerial Vehicles (UAVs) are increasingly used in forestry as they are economical and flexible. This study aims to present the advantages of the drone photogrammetry method in collecting individual tree crowns, as individual tree crown detection could deliver essential ecological and economic information. The referred accuracy for individual tree crown extraction is 79.2%. Only crowns that were clearly visible were selected and manually delineated on the image because the distribution of the true crown size is significantly different from the segmented crowns. The aim of this study is to investigate UAVs orthomosaics in individual tree crown detection. The objectives of this study are to produce the orthomosaic of tree crown extraction mapping using the Pix4D software and analyze the tree crowns using tree crown delineation and the OBIA algorithm. Data processing involves the processing of aerial images using Pix4Dmapper. Automatic tree crown detection involves a tree crown d...

Tree crown plays a crucial role in creating urban characters and spatial arrangements of living e... more Tree crown plays a crucial role in creating urban characters and spatial arrangements of living environment towards a green-sustainable city. It provides the fundamental needs for human’s living quality and health conditions such as improving water quality, preserving energy, minimising greenhouse gasses, and beautification and comfortable purposes. Therefore, there is a need for urban planners to recognise its importance and plan for it wisely. This paper attempts to demonstrate a mapping tree crowns for a case of the residential neighbourhood using Unmanned Aerial Vehicle (UAV) based GIS technologies. Four main stages involved in a mapping tree crown process namely: flight planning, data acquisition, data processing and analyses and results. As a result, this paper able to show the capabilities of the technologies in measuring and mapping tree crowns for the residential neighbourhood. Moreover, it provides urban planners with informative scenario of the tree planting and clarifies...

Alinteri Journal of Agriculture Sciences, 2021

The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, h... more The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, hydrographic surveyors often have sparse data, and even though the data is dense and equal distances, there is still a gap in time. This paper present coastal depth extraction from satellite images. The problem encountered during the bathymetry derivation process and the problem related to the space, distribution and quantity of the Single-beam echo sounder (SBES) data. Therefore, the idea of using spatial interpolation could be a suitable approach in solving the problems. This study intends to produce Satellite-Derived Bathymetry (SDB) from Landsat 8 images at Pantai Tok Jembal, Terengganu, Malaysia. The proposed method by first interpolating the SBES point in the calibration data using spatial predictors, i.e. Inverse Distance Weightage, Thin-Plate Spline, Spline with Tension, Universal Kriging, Natural Neighbor, and Topo to Raster. Second, the raster output created from the interpolati...

Managing and planning depot area consisting of shipping containers are of high interest in transp... more Managing and planning depot area consisting of shipping containers are of high interest in transport and logistics. The role of Unmanned Aerial Vehicle (UAV) in fast mapping for a shipping containers depot is demonstrated. The technique comprises of UAV fitted with high resolution digital camera to capture aerial images covering the depot area. The aerial images are captured in series with calculated overlaps for the construction of 3D models and orthophoto by utilizing the photogrammetric techniques. Orthophoto is an aerial photograph or image geometrically corrected such that the scale is uniform and depicts a map. Information such as the 3D models and orthophoto will be of high value towards managing and planning of depot area. Apart from the 3D model and orthophoto constructed, an automated counting of the shipping containers for the depot area based on the 3D models constructed will also be demonstrated. Constructed 3D models, orthophoto and the automatic approached in coun...

Article history: Received 11 February 2017 Received in revised form 16 March 2017 Accepted 26 Mar... more Article history: Received 11 February 2017 Received in revised form 16 March 2017 Accepted 26 March 2017 Available online 4 April 2017 Camera calibration has always been an essential component in photogrammetric measurement. Nowadays, self-calibration is being integral and routinely applied operations within photogrammetric triangulation, especially in high accuracy close range measurement. This study is to compare the accuracy of different types of software in order to determine the correct technique based on two different calibrations software. The objective of this study is to analyze the accuracy based on different resolution, to assess the calibration result based on two different software and to evaluate the best technique in camera calibration. Based on this study, the data involves are image of calibration sheet from different camera resolutions, good and bad light conditions and different flash conditions. This is the three types of data needed in this study before next pro...

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020

Traffic accidents are one of the major causes of fatality in developing countries. The aim of the... more Traffic accidents are one of the major causes of fatality in developing countries. The aim of the study is to reconstruct accident scenes by using UAV photogrammetry. The methodology of this study is organised into four main phases which consist of preliminary work, flight planning, 3D model processing and analysis of the results. The 3D model was successfully generated by using Point of Interest (POI) flight planning. The 3D model showed that the results of the process produced good 3D texture where the two vehicles had good shapes and could be seen clearly from an oblique view. In addition, the effect of the tyres on the road could also be seen clearly and had good shape which were generated accurately. The accuracy values obtained from the POI technique and waypoint technique were 0.059m and 0.043m, respectively. Due to the availability of UAVs in the market at reasonable costs, photogrammetry offers the best alternative technique to other methods that have been used to reconstruct the accident scene.

Built Environment Journal, 2019

In Malaysia, the existing of counting approach on the shipping container at depot is carried out ... more In Malaysia, the existing of counting approach on the shipping container at depot is carried out by manual based system. This has made the efficiency of the method to be questioned which can be solved through automation. Under previous studies, Unmanned Aerial Vehicle (UAV) is demonstrated for automatic counting of cars and trees. Therefore, the possibility for shipping container counting is highly required in which promotes low-cost alternative and automatedpilot for data collection. Based on this study, the aerial images captured using UAV is combined with geographical information processing software, ArcGIS, towards automated approach for container counting. The overlapping aerial images are post-processed using photogrammetric technique to produce Digital Surface Model (DSM) that represents the ground and above surface feature’s elevations. Then, the constructed DSM is filtered to develop Digital Terrain Model (DTM) where it represents the ground surface’s elevation only. Then, ...

Indonesian Journal of Electrical Engineering and Computer Science, 2020

The current techniques to extract building footprints frequently involve Light Detection and Rang... more The current techniques to extract building footprints frequently involve Light Detection and Ranging (LiDAR), as well as satellite images. The UAV is proposed to acquire aerial imagery in this study as it is more efficient, time-efficient, and inexpensive, especially for small budget projects. Hence, this study evaluated the building footprints from different UAV platforms. The objectives of this study are to perform the different UAV image processing of building footprints using fixed-wing UAV and multi-rotor UAV, as well as to analyse the outcomes of building footprints from different UAV platforms with existing layout plans. The methodology begins with a preliminary study, and continued with acquisition of data via UAV, data processing, and lastly, analyses of the outcome from different platforms. Based on the analysis in terms of area, the accuracy gained by using multi rotor UAV had been better than that for fixed wing UAV with area difference of 13.648 m² compared to 18.091 m²...

International Journal of Optics, 2018

Unmanned Aerial Vehicles (UAVs) can be used for close range mapping. In engineering survey works,... more Unmanned Aerial Vehicles (UAVs) can be used for close range mapping. In engineering survey works, the conventional survey involves huge cost, labour, and time. Low-cost UAVs are very practical in providing reliable information for many applications such as road design. UAVs can provide the output that meets the accuracy of engineering surveys and policies, especially for small-scale mapping. UAVs are also a competitive technology which is stable and rapidly developing, same as other surveying technologies. This study investigates the performance of multirotor UAV for road design. This study involves four phases which consist of preliminary study, data collection, data processing, and analysis. This study focuses on the UAV as a tool to capture data of the ground from a certain altitude. The analysis includes UAV flight planning, image acquisition, and accuracy assessment of road design. It can be concluded that UAVs can be used to provide data for road design with reliable accuracy.

International Journal of Building Pathology and Adaptation, 2019

Purpose The current technique used to measure construction is the conventional total station meth... more Purpose The current technique used to measure construction is the conventional total station method. However, the conventional method is time-consuming and could not be used to create a photo-realistic three-dimensional (3D) model of an object. Furthermore, the Canseleri building is located at a slope. The paper aims to discuss this issue. Design/methodology/approach The aim of this study is to assess the geometric accuracy of a 3D model using unmanned aerial vehicle (UAV) images. There are two objectives in this study. The first is to construct a 3D model of the Canseleri building using UAV images. The second objective is to validate the 3D model of the Canseleri building based on actual measurements. Findings The close-range photogrammetry method, using the UAV platform, was able to produce a 3D building model. The results show that the errors between the actual measurement and the generated 3D model were less than 4 cm. The accuracy of the 3D model achieved in this study was abou...

International Journal of Optics, 2019

Surf zone is a sand area that stretches inside a breaking wave to limit the rise and fall of wave... more Surf zone is a sand area that stretches inside a breaking wave to limit the rise and fall of waves on the beach. Advanced technology in the geomatics field offers a fast and accurate solution to produce surf zone maps. The demand for surf zone map is increasing during the monsoon season, especially at coastal areas. Nowadays, the Unmanned Aerial Vehicle (UAV) or drone has become popular platform in the geospatial and surveying field. The aim of this study is to produce surf zone 3D surface mapping by using a multirotor Unmanned Aerial Vehicle. There are four phases in this study which are image acquisition, UAV image processing, photogrammetric results, and analysis. The image acquisition was solely obtained using a multirotor UAV based on the photogrammetric concept. The acquired UAV images were processed using commercial software with a specific workflow. Photogrammetric products such as digital elevation model, orthophoto, contour, and surf map zone were produced. The analyses of...

Open Access Journal of Science, 2017

The terrestrial laser scanner is a new technology which is use remote sensing and photogrammetric... more The terrestrial laser scanner is a new technology which is use remote sensing and photogrammetric concept as efficient tools for fast and reliable three-dimensional point cloud data acquisition. This technology can measure a very high accuracy point cloud per minutes and this instrument is reflector less and contactless of acquisition of a point cloud by using the time of flight distance measurement of an infrared laser pulse. This study focuses on the capability of TLS in slope mapping. The objectives of this study are to generate 3D slope model based on various resolutions and to study the different attribute for each resolution. The resolutions that use such as 5mm, 10mm, 15mm and 20mm resolution. This study has been conducted at Tanah Rata Cameron Highland, Pahang Malaysia. The data acquisition is conducted at the selected slope at Tanah Rata using Topcon GLS1500 laser scanner. Ground control points are established using, Real Time Kinematic to provide a local coordinates system for laser scanner's data position. 1 The different resolution has been evaluated based on the slope mapping pattern. In this study, it was found that the resolution gives an effect in slope mapping pattern. Each resolution has each suitable degree of slope. Therefore, the scanning resolution needs to be identified according to the application.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2013

This paper presents a novel method of unmanned aerial vehicle image processing using photogrammet... more This paper presents a novel method of unmanned aerial vehicle image processing using photogrammetric technique. The study area consist different slope class which involves undulating area around the Skudai area, Malaysia. All photogrammetric methods were applied in this study including selection of test area, flight planning, camera calibration and image processing orientation. A new ground control point configurations is introduced in this study as a generic approach in unmanned aerial vehicle photogrammetric block. These configurations are used to determine the best photogrammetric results based on number of ground control points in the photogrammetric block during image processing. The objective of this study is to determine the best configuration for photogrammetric block in order to produce the best photogrammetric products. Photogrammetric image processing involves two main orientations which are known as interior orientation and exterior orientation. Interior orientation involves the parameters of camera in order to calibrate the image in the same position as during the image acquisition. Exterior orientation involves the measurement of tie points to tie up all images in the strips until photogrammetric block. In this study, six ground control point configurations were tested to determine the best photogrammetric results. In this study, two main photogrammetric results were produced namely digital orthophoto and digital elevation model. The verification results show that all configurations recorded coefficient percentage of more than 97 % accuracy for the six configurations. The validation results conclude that ground control point plays an important role in photogrammetric block to acquire the accurate photogrammetric results. In this study eight and nine ground control point configurations are the best configurations among the others. Qualitatively, vector plot error for easting and northing coordinates can be viewed graphically to distinguish the error and direction for all configurations which has been proposed in this study.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015

Most of consultation work only involves a small area, especially for slope mapping studies. The o... more Most of consultation work only involves a small area, especially for slope mapping studies. The objective of this study is to evaluate the accuracy of slope mapping results from different altitudes at semi-undulated area and undulated area. Multi-rotor UAV is used as an instrument for data acquisition for this study. The images of slope were captured from five different altitudes in the same study area. All images were processed using photogrammetric software to produce digital elevation models and digital orthophoto. In this study, slope map from all different altitudes were identified and recorded for analysis purposes. It was found that the accuracy of slope is increase when altitude is increase. In conclusion, the condition of slope such as semi-undulated and undulated area did have an influence on the slope accuracy.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015

Height accuracy is one of the important elements in surveying work especially for control point's... more Height accuracy is one of the important elements in surveying work especially for control point's establishment which requires an accurate measurement. There are many methods can be used to acquire height value such as tacheometry, leveling and Global Positioning System (GPS). This study has investigated the effect on height accuracy based on different observations which are single based and network based GPS methods. The GPS network is acquired from the local network namely Iskandar network. This network has been setup to provide real-time correction data to rover GPS station while the single network is based on the known GPS station. Nine ground control points were established evenly at the study area. Each ground control points were observed about two and ten minutes. It was found that, the height accuracy give the different result for each observation.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012

This paper looks into the latest achievement in the low-cost Unmanned Aerial Vehicle (UAV) techno... more This paper looks into the latest achievement in the low-cost Unmanned Aerial Vehicle (UAV) technology in their capacity to map the semi-development areas. The objectives of this study are to establish a new methodology or a new algorithm in image registration during interior orientation process and to determine the accuracy of the photogrammetric products by using UAV images. Recently, UAV technology has been used in several applications such as mapping, agriculture and surveillance. The aim of this study is to scrutinize the usage of UAV to map the semi-development areas. The performance of the low cost UAV mapping study was established on a study area with two image processing methods so that the results could be comparable. A non-metric camera was attached at the bottom of UAV and it was used to capture images at both sites after it went through several calibration steps. Calibration processes were carried out to determine focal length, principal distance, radial lens distortion, tangential lens distortion and affinity. A new method in image registration for a non-metric camera is discussed in this paper as a part of new methodology of this study. This method used the UAV Global Positioning System (GPS) onboard to register the UAV image for interior orientation process. Check points were established randomly at both sites using rapid static Global Positioning System. Ground control points are used for exterior orientation process, and check point is used for accuracy assessment of photogrammetric product. All acquired images were processed in a photogrammetric software. Two methods of image registration were applied in this study, namely, GPS onboard registration and ground control point registration. Both registrations were processed by using photogrammetric software and the result is discussed. Two results were produced in this study, which are the digital orthophoto and the digital terrain model. These results were analyzed by using the root mean square errors and mean absolute error to determine the level of accuracy and the precision of photogrammetric products. It can be concluded that the new method of image registration by using the GPS onboard of the UAV produces medium accuracy result compared to the method that uses the ground control point. This new method can be used for the medium accuracy requirements. Unmanned Aerial Vehicle can be used for several applications, which requires a medium accuracy.

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016

The establishment of ground control points is a critical issue in mapping field, especially for l... more The establishment of ground control points is a critical issue in mapping field, especially for large scale mapping. The fast and rapid technique for ground control point’s establishment is very important for small budget projects. UAV onboard GPS has the ability to determine the point positioning. The objective of this research is to assess the accuracy of unmanned aerial vehicle onboard global positioning system in positioning determination. Therefore, this research used UAV onboard GPS as an alternative to determine the point positioning at the selected area. UAV is one of the powerful tools for data acquisition and it is used in many applications all over the world. This research concentrates on the error contributed from the UAV onboard GPS during observation. There are several points that have been used to study the pattern of positioning error. All errors were analyzed in world geodetic system 84- coordinate system, which is the basic coordinate system used by the global posi...

Malaysian Journal of Society and Space

Pothole's defect is major damages indicated the road condition visually, and the structural defec... more Pothole's defect is major damages indicated the road condition visually, and the structural defects due to some potential causes. Nowadays, new forms of remote sensing technique were widely used, but less studies in the application of low altitude multispectral mapping. The potential of multispectral images is its help better in resolution due to its spectral characteristic. Hence, it helps a lot in feature classification with proper training sample, classifier used, and spectral band composite. Thus, this study aims to extract the defective roads by using the multispectral image of Parrot Sequoia with low flight altitude. This study tries to detect a pothole's existence from band combination and supervised classification other than its common use which ultimately for agriculture purposes. The classifier used in this is Maximum Likelihood, Support vector machine (SVM) and Mahalanobis Distance. 15 different probability of band stacks of green, NIR, red edge, and red band were used as multispectral images. The comparison of the performance between the types of classifier and band combination was modeled and discussed in this study. Classifier algorithm maximum likelihood gives the lowest error of 0.108m² with a combination of NIR + red edge band. SVM gives the lowest error of 0.427m² with a combination of green + NIR + red edge + red band. While Mahalanobis distance gives the lowest error of-0.082m² with a combination of red edge + red band. Averagely, Mahalanobis distance gives the lowest error of 0.299m² of all bands used.

International Journal of Electrical and Computer Engineering (IJECE)

At the current stage, an investigation technique on the accident takes a longer time and this cau... more At the current stage, an investigation technique on the accident takes a longer time and this causes longer traffic congestion. The aim of this study is to reconstruct a 3D model of an accident scene using an unmanned aerial vehicle (UAV). The flight parameters that have been chosen are the circular method, the double grid method, and the single grid method. All these designs can produce a good 3D model to achieve the study’s objective. The methodology in this study is divided into 4 phases which are preliminary work, data acquisition, data processing, and data analysis. The main results of this study are the 3D model of the accident scene, an orthophoto map layout, and an accuracy assessment of a 3D model of reconstructed accident scene. All these parameters will be tested on accuracy based on the root mean square error (RMSE) value, comparing the UAV data and site measurement data. This objective has been tested for 10 different types of processing and different types of flight pa...

IOP Conference Series: Earth and Environmental Science, 2021

Unmanned Aerial Vehicles (UAVs) are aircrafts without pilot on board, which are controlled by the... more Unmanned Aerial Vehicles (UAVs) are aircrafts without pilot on board, which are controlled by the ground station or transmitter. The ability of UAVs to provide high-resolution imageries and accurate positioning makes it the best platform as compared to satellite images. Therefore, UAVs can speed up the topographic works, especially during data collection. Topographic mapping has been used by many agencies such as the government, private, and military. Furthermore, the geotagged high resolution UAV images can provide accurate results using Ground Control Points (GCPs). UAV flight parameters, such as flight altitude and overlap and sidelap percentages, can affect the topographic map result derived from the UAV images. The optimal flight altitude and overlap and sidelap percentages based on the specific topographic surface need to be investigated to produce an accurate topographic map. The aim of this study is to assess the accuracy of topographic maps from different flight parameters....

Engineering, Technology & Applied Science Research, 2021

Unmanned Aerial Vehicles (UAVs) are increasingly used in forestry as they are economical and flex... more Unmanned Aerial Vehicles (UAVs) are increasingly used in forestry as they are economical and flexible. This study aims to present the advantages of the drone photogrammetry method in collecting individual tree crowns, as individual tree crown detection could deliver essential ecological and economic information. The referred accuracy for individual tree crown extraction is 79.2%. Only crowns that were clearly visible were selected and manually delineated on the image because the distribution of the true crown size is significantly different from the segmented crowns. The aim of this study is to investigate UAVs orthomosaics in individual tree crown detection. The objectives of this study are to produce the orthomosaic of tree crown extraction mapping using the Pix4D software and analyze the tree crowns using tree crown delineation and the OBIA algorithm. Data processing involves the processing of aerial images using Pix4Dmapper. Automatic tree crown detection involves a tree crown d...

Tree crown plays a crucial role in creating urban characters and spatial arrangements of living e... more Tree crown plays a crucial role in creating urban characters and spatial arrangements of living environment towards a green-sustainable city. It provides the fundamental needs for human’s living quality and health conditions such as improving water quality, preserving energy, minimising greenhouse gasses, and beautification and comfortable purposes. Therefore, there is a need for urban planners to recognise its importance and plan for it wisely. This paper attempts to demonstrate a mapping tree crowns for a case of the residential neighbourhood using Unmanned Aerial Vehicle (UAV) based GIS technologies. Four main stages involved in a mapping tree crown process namely: flight planning, data acquisition, data processing and analyses and results. As a result, this paper able to show the capabilities of the technologies in measuring and mapping tree crowns for the residential neighbourhood. Moreover, it provides urban planners with informative scenario of the tree planting and clarifies...

Alinteri Journal of Agriculture Sciences, 2021

The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, h... more The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, hydrographic surveyors often have sparse data, and even though the data is dense and equal distances, there is still a gap in time. This paper present coastal depth extraction from satellite images. The problem encountered during the bathymetry derivation process and the problem related to the space, distribution and quantity of the Single-beam echo sounder (SBES) data. Therefore, the idea of using spatial interpolation could be a suitable approach in solving the problems. This study intends to produce Satellite-Derived Bathymetry (SDB) from Landsat 8 images at Pantai Tok Jembal, Terengganu, Malaysia. The proposed method by first interpolating the SBES point in the calibration data using spatial predictors, i.e. Inverse Distance Weightage, Thin-Plate Spline, Spline with Tension, Universal Kriging, Natural Neighbor, and Topo to Raster. Second, the raster output created from the interpolati...

Managing and planning depot area consisting of shipping containers are of high interest in transp... more Managing and planning depot area consisting of shipping containers are of high interest in transport and logistics. The role of Unmanned Aerial Vehicle (UAV) in fast mapping for a shipping containers depot is demonstrated. The technique comprises of UAV fitted with high resolution digital camera to capture aerial images covering the depot area. The aerial images are captured in series with calculated overlaps for the construction of 3D models and orthophoto by utilizing the photogrammetric techniques. Orthophoto is an aerial photograph or image geometrically corrected such that the scale is uniform and depicts a map. Information such as the 3D models and orthophoto will be of high value towards managing and planning of depot area. Apart from the 3D model and orthophoto constructed, an automated counting of the shipping containers for the depot area based on the 3D models constructed will also be demonstrated. Constructed 3D models, orthophoto and the automatic approached in coun...

Article history: Received 11 February 2017 Received in revised form 16 March 2017 Accepted 26 Mar... more Article history: Received 11 February 2017 Received in revised form 16 March 2017 Accepted 26 March 2017 Available online 4 April 2017 Camera calibration has always been an essential component in photogrammetric measurement. Nowadays, self-calibration is being integral and routinely applied operations within photogrammetric triangulation, especially in high accuracy close range measurement. This study is to compare the accuracy of different types of software in order to determine the correct technique based on two different calibrations software. The objective of this study is to analyze the accuracy based on different resolution, to assess the calibration result based on two different software and to evaluate the best technique in camera calibration. Based on this study, the data involves are image of calibration sheet from different camera resolutions, good and bad light conditions and different flash conditions. This is the three types of data needed in this study before next pro...

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020

Traffic accidents are one of the major causes of fatality in developing countries. The aim of the... more Traffic accidents are one of the major causes of fatality in developing countries. The aim of the study is to reconstruct accident scenes by using UAV photogrammetry. The methodology of this study is organised into four main phases which consist of preliminary work, flight planning, 3D model processing and analysis of the results. The 3D model was successfully generated by using Point of Interest (POI) flight planning. The 3D model showed that the results of the process produced good 3D texture where the two vehicles had good shapes and could be seen clearly from an oblique view. In addition, the effect of the tyres on the road could also be seen clearly and had good shape which were generated accurately. The accuracy values obtained from the POI technique and waypoint technique were 0.059m and 0.043m, respectively. Due to the availability of UAVs in the market at reasonable costs, photogrammetry offers the best alternative technique to other methods that have been used to reconstruct the accident scene.

Built Environment Journal, 2019

In Malaysia, the existing of counting approach on the shipping container at depot is carried out ... more In Malaysia, the existing of counting approach on the shipping container at depot is carried out by manual based system. This has made the efficiency of the method to be questioned which can be solved through automation. Under previous studies, Unmanned Aerial Vehicle (UAV) is demonstrated for automatic counting of cars and trees. Therefore, the possibility for shipping container counting is highly required in which promotes low-cost alternative and automatedpilot for data collection. Based on this study, the aerial images captured using UAV is combined with geographical information processing software, ArcGIS, towards automated approach for container counting. The overlapping aerial images are post-processed using photogrammetric technique to produce Digital Surface Model (DSM) that represents the ground and above surface feature’s elevations. Then, the constructed DSM is filtered to develop Digital Terrain Model (DTM) where it represents the ground surface’s elevation only. Then, ...

Indonesian Journal of Electrical Engineering and Computer Science, 2020

The current techniques to extract building footprints frequently involve Light Detection and Rang... more The current techniques to extract building footprints frequently involve Light Detection and Ranging (LiDAR), as well as satellite images. The UAV is proposed to acquire aerial imagery in this study as it is more efficient, time-efficient, and inexpensive, especially for small budget projects. Hence, this study evaluated the building footprints from different UAV platforms. The objectives of this study are to perform the different UAV image processing of building footprints using fixed-wing UAV and multi-rotor UAV, as well as to analyse the outcomes of building footprints from different UAV platforms with existing layout plans. The methodology begins with a preliminary study, and continued with acquisition of data via UAV, data processing, and lastly, analyses of the outcome from different platforms. Based on the analysis in terms of area, the accuracy gained by using multi rotor UAV had been better than that for fixed wing UAV with area difference of 13.648 m² compared to 18.091 m²...

International Journal of Optics, 2018

Unmanned Aerial Vehicles (UAVs) can be used for close range mapping. In engineering survey works,... more Unmanned Aerial Vehicles (UAVs) can be used for close range mapping. In engineering survey works, the conventional survey involves huge cost, labour, and time. Low-cost UAVs are very practical in providing reliable information for many applications such as road design. UAVs can provide the output that meets the accuracy of engineering surveys and policies, especially for small-scale mapping. UAVs are also a competitive technology which is stable and rapidly developing, same as other surveying technologies. This study investigates the performance of multirotor UAV for road design. This study involves four phases which consist of preliminary study, data collection, data processing, and analysis. This study focuses on the UAV as a tool to capture data of the ground from a certain altitude. The analysis includes UAV flight planning, image acquisition, and accuracy assessment of road design. It can be concluded that UAVs can be used to provide data for road design with reliable accuracy.

International Journal of Building Pathology and Adaptation, 2019

Purpose The current technique used to measure construction is the conventional total station meth... more Purpose The current technique used to measure construction is the conventional total station method. However, the conventional method is time-consuming and could not be used to create a photo-realistic three-dimensional (3D) model of an object. Furthermore, the Canseleri building is located at a slope. The paper aims to discuss this issue. Design/methodology/approach The aim of this study is to assess the geometric accuracy of a 3D model using unmanned aerial vehicle (UAV) images. There are two objectives in this study. The first is to construct a 3D model of the Canseleri building using UAV images. The second objective is to validate the 3D model of the Canseleri building based on actual measurements. Findings The close-range photogrammetry method, using the UAV platform, was able to produce a 3D building model. The results show that the errors between the actual measurement and the generated 3D model were less than 4 cm. The accuracy of the 3D model achieved in this study was abou...

International Journal of Optics, 2019

Surf zone is a sand area that stretches inside a breaking wave to limit the rise and fall of wave... more Surf zone is a sand area that stretches inside a breaking wave to limit the rise and fall of waves on the beach. Advanced technology in the geomatics field offers a fast and accurate solution to produce surf zone maps. The demand for surf zone map is increasing during the monsoon season, especially at coastal areas. Nowadays, the Unmanned Aerial Vehicle (UAV) or drone has become popular platform in the geospatial and surveying field. The aim of this study is to produce surf zone 3D surface mapping by using a multirotor Unmanned Aerial Vehicle. There are four phases in this study which are image acquisition, UAV image processing, photogrammetric results, and analysis. The image acquisition was solely obtained using a multirotor UAV based on the photogrammetric concept. The acquired UAV images were processed using commercial software with a specific workflow. Photogrammetric products such as digital elevation model, orthophoto, contour, and surf map zone were produced. The analyses of...

Open Access Journal of Science, 2017

The terrestrial laser scanner is a new technology which is use remote sensing and photogrammetric... more The terrestrial laser scanner is a new technology which is use remote sensing and photogrammetric concept as efficient tools for fast and reliable three-dimensional point cloud data acquisition. This technology can measure a very high accuracy point cloud per minutes and this instrument is reflector less and contactless of acquisition of a point cloud by using the time of flight distance measurement of an infrared laser pulse. This study focuses on the capability of TLS in slope mapping. The objectives of this study are to generate 3D slope model based on various resolutions and to study the different attribute for each resolution. The resolutions that use such as 5mm, 10mm, 15mm and 20mm resolution. This study has been conducted at Tanah Rata Cameron Highland, Pahang Malaysia. The data acquisition is conducted at the selected slope at Tanah Rata using Topcon GLS1500 laser scanner. Ground control points are established using, Real Time Kinematic to provide a local coordinates system for laser scanner's data position. 1 The different resolution has been evaluated based on the slope mapping pattern. In this study, it was found that the resolution gives an effect in slope mapping pattern. Each resolution has each suitable degree of slope. Therefore, the scanning resolution needs to be identified according to the application.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2013

This paper presents a novel method of unmanned aerial vehicle image processing using photogrammet... more This paper presents a novel method of unmanned aerial vehicle image processing using photogrammetric technique. The study area consist different slope class which involves undulating area around the Skudai area, Malaysia. All photogrammetric methods were applied in this study including selection of test area, flight planning, camera calibration and image processing orientation. A new ground control point configurations is introduced in this study as a generic approach in unmanned aerial vehicle photogrammetric block. These configurations are used to determine the best photogrammetric results based on number of ground control points in the photogrammetric block during image processing. The objective of this study is to determine the best configuration for photogrammetric block in order to produce the best photogrammetric products. Photogrammetric image processing involves two main orientations which are known as interior orientation and exterior orientation. Interior orientation involves the parameters of camera in order to calibrate the image in the same position as during the image acquisition. Exterior orientation involves the measurement of tie points to tie up all images in the strips until photogrammetric block. In this study, six ground control point configurations were tested to determine the best photogrammetric results. In this study, two main photogrammetric results were produced namely digital orthophoto and digital elevation model. The verification results show that all configurations recorded coefficient percentage of more than 97 % accuracy for the six configurations. The validation results conclude that ground control point plays an important role in photogrammetric block to acquire the accurate photogrammetric results. In this study eight and nine ground control point configurations are the best configurations among the others. Qualitatively, vector plot error for easting and northing coordinates can be viewed graphically to distinguish the error and direction for all configurations which has been proposed in this study.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015

Most of consultation work only involves a small area, especially for slope mapping studies. The o... more Most of consultation work only involves a small area, especially for slope mapping studies. The objective of this study is to evaluate the accuracy of slope mapping results from different altitudes at semi-undulated area and undulated area. Multi-rotor UAV is used as an instrument for data acquisition for this study. The images of slope were captured from five different altitudes in the same study area. All images were processed using photogrammetric software to produce digital elevation models and digital orthophoto. In this study, slope map from all different altitudes were identified and recorded for analysis purposes. It was found that the accuracy of slope is increase when altitude is increase. In conclusion, the condition of slope such as semi-undulated and undulated area did have an influence on the slope accuracy.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015

Height accuracy is one of the important elements in surveying work especially for control point's... more Height accuracy is one of the important elements in surveying work especially for control point's establishment which requires an accurate measurement. There are many methods can be used to acquire height value such as tacheometry, leveling and Global Positioning System (GPS). This study has investigated the effect on height accuracy based on different observations which are single based and network based GPS methods. The GPS network is acquired from the local network namely Iskandar network. This network has been setup to provide real-time correction data to rover GPS station while the single network is based on the known GPS station. Nine ground control points were established evenly at the study area. Each ground control points were observed about two and ten minutes. It was found that, the height accuracy give the different result for each observation.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012

This paper looks into the latest achievement in the low-cost Unmanned Aerial Vehicle (UAV) techno... more This paper looks into the latest achievement in the low-cost Unmanned Aerial Vehicle (UAV) technology in their capacity to map the semi-development areas. The objectives of this study are to establish a new methodology or a new algorithm in image registration during interior orientation process and to determine the accuracy of the photogrammetric products by using UAV images. Recently, UAV technology has been used in several applications such as mapping, agriculture and surveillance. The aim of this study is to scrutinize the usage of UAV to map the semi-development areas. The performance of the low cost UAV mapping study was established on a study area with two image processing methods so that the results could be comparable. A non-metric camera was attached at the bottom of UAV and it was used to capture images at both sites after it went through several calibration steps. Calibration processes were carried out to determine focal length, principal distance, radial lens distortion, tangential lens distortion and affinity. A new method in image registration for a non-metric camera is discussed in this paper as a part of new methodology of this study. This method used the UAV Global Positioning System (GPS) onboard to register the UAV image for interior orientation process. Check points were established randomly at both sites using rapid static Global Positioning System. Ground control points are used for exterior orientation process, and check point is used for accuracy assessment of photogrammetric product. All acquired images were processed in a photogrammetric software. Two methods of image registration were applied in this study, namely, GPS onboard registration and ground control point registration. Both registrations were processed by using photogrammetric software and the result is discussed. Two results were produced in this study, which are the digital orthophoto and the digital terrain model. These results were analyzed by using the root mean square errors and mean absolute error to determine the level of accuracy and the precision of photogrammetric products. It can be concluded that the new method of image registration by using the GPS onboard of the UAV produces medium accuracy result compared to the method that uses the ground control point. This new method can be used for the medium accuracy requirements. Unmanned Aerial Vehicle can be used for several applications, which requires a medium accuracy.

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016

The establishment of ground control points is a critical issue in mapping field, especially for l... more The establishment of ground control points is a critical issue in mapping field, especially for large scale mapping. The fast and rapid technique for ground control point’s establishment is very important for small budget projects. UAV onboard GPS has the ability to determine the point positioning. The objective of this research is to assess the accuracy of unmanned aerial vehicle onboard global positioning system in positioning determination. Therefore, this research used UAV onboard GPS as an alternative to determine the point positioning at the selected area. UAV is one of the powerful tools for data acquisition and it is used in many applications all over the world. This research concentrates on the error contributed from the UAV onboard GPS during observation. There are several points that have been used to study the pattern of positioning error. All errors were analyzed in world geodetic system 84- coordinate system, which is the basic coordinate system used by the global posi...