Khairil Afendy Hashim

Digital aerial imagery of unmanned aerial vehicle for various applications

Digital aerial imagery (DAI) can be acquired using digital mapping camera attached to light aircraft. The DAI is used for the production of topographic and thematic map. The cost of acquiring DAI is very expensive and suitable for large area coverage. The acquisition of DAI is not economical and suitable for small area coverage. Therefore an alternative method should be used to fulfill this need. There are two alternative methods that can be used for acquisition of DAI which include using a small format digital camera attached to light aircraft and using a small format attached to an unmanned aerial vehicle (UAV). UAV system has been reported used in various and diversified applications such as mapping applications (eg. map revision, landslide, coastal erosion, archaeology, forestry), industrial application (eg. engineering, crash accident), Geographic Information System (GIS) applications and others. In this study, micro unmanned aerial vehicle (UAV) systems which comprise of fixed wing UAV flying and rotary UAV are attached with small format high resolution digital camera to acquire DAI for the purpose of mapping at the flying height of 300m at 100m respectively. The micro UAVs were flown autonomously (i.e automatically) and a series of DAIs of a slope using fixed wing UAV and a stream using rotary UAV were acquired rapidly within short period. Ground control point (GCP) and check point (CP) were established using the Global Positioning System and conventional Total Station techniques around the study area for the slope and stream respectively for the purpose of digital image processing and accuracy assessment. The DAIs were processed to produce photogrammetric output such as digital elevation model (DEM) and orthophoto. All these photogrammetric products were successfully produced and assessed. The achievable accuracy is less than ±1m for slope mapping and ±0.280m for stream mapping. In this study, it is proven that the micro UAV system can be used for mapping which cover small area. As conclusion, micro UAV is suitable for mapping small area, rapid data acquisition, accurate, low cost and can be employed for various applications.

A study on flood risk assessment for Bandar Segamat sustainability using remote sensing and GIS approach

Flood is one of the natural disaster usually take place that in the southern states of Malaysia such as Johor, Pahang and Malacca during rainy season. The number of area affected from this event has increase over the past years. This paper describes a study made to explore the application of GIS and Remote Sensing in flood risk assessment for Bandar Segamat sustainability. The objective is to explore and understand the flood risk assessment characteristics, Remote Sensing (RS) and Geographic Information System (GIS). Open source software such as QuantimGIS and Infoworks RS is used as tools in processing the data. The result show a significant movement of water in Segamat city which causing such loss in terms of property damages and lives. A simulation of flood risk and sustainability at Bandar Segamat was developed which indicate the most, moderate and less affected area in Segamat. The main contribution of the study was to prove that anyone that involved directly or indirectly in GIS or RS field are able to perform the similar study without the need of high cost, great experience and with basic knowledge of the field study.

Assessment of low altitude aerial data for large scale urban environmental mapping

Development of UAV systems become more popular for missions with high societal impact. Therefore, UAV is developed from the low-altitude photogrammetric mapping to perform the accuracy of the aerial photography and the resolution of the image. The objective of this study is to assess the accuracy of the photogrammetric output i.e. Digital Elevation Model (DEM) and orthophoto. The Ground Control Points (GCPs) and Check Points (CPs) are established using Rapid Static techniques through GPS observation for registration purpose in photogrammetric process. The GCPs is used in the photogrammetric processes to produce photogrammetric output while the CP is employed for accuracy assessment. A Pentax Optio W90 consumer digital camera is also used in image acquisition of the aerial photograph. Besides, this study also involves image processing and map production using Erdas Imagine 8.6 software. The accuracy of the orthophoto is determined using the equation of Root Mean Square Error (RMSE). In a nutshell, UAV system has potential use for large scale urban environmental mapping in field of surveying and other diversified urban environmental applications especially for small area which has limited time and less man power.

3D images processing of structural building using Digital Close-Range Photogrammetric Approach

This paper presents a comprehensive research study in mapping of structural building using Digital Close-Range Photogrammetric Approach. The building chosen for this research study is Ipoh Old General Post Office. Digital Close-Range Photogrammetric approach is capable in 3D mapping of building and able to deliver an accurate measurements, less in time then conventional approach (ie. total station / tape measurement). 3D point was extrapolated from 2D images acquired from various angles at the scene and fed into photogrammetric processor that capable in producing 3D model. This research study shows that user is able to navigate throughout the building with ease and accuracy. The images created in 3D model are irrefutable recording of the 3D points and lot of data can be interpreted and is presented as final outcome.

A study on school location suitability using AHP in GIS approach

The National Education System at school level under the government education institution category consists of preschool, primary, secondary and post-secondary education. Ministry of education has many departments and division with a lot of aim, objective and task to produce Malaysian citizens who will be knowledgeable and competent, possess high moral standards, responsible and capable of achieving high level of personal well-being for harmony and betterment of the family, the society and nation contribution. This research is focus on i). The suitability study of existing school distribution/location and ii). The determination of new school location at Negeri Perlis Indera Kayangan. Perhap with the increments number of population nowadays, this is the right time for a school suitability location determination study in order to determine i). The Most Suitable, ii). Suitable and iiii). Less Suitable location for existing and new school in Negeri Perlis Indera Kayangan. The use of AHP (Analytical Hierarchy Process) in GIS approach was implemented and the results show that the most, suitable and less suitable has been successfully presented for Perlis State.

A review of WEB - based GIS for visualization of George Town, Penang sustainability as world heritage site

Integration of the Geographical Information System (GIS) technology and various applications are able to contribute towards reconstructing the dynamic of representation in GIS visualization. WEB-based GIS visualization users like architects, planners, landuse planners and urban designers are capable to visualize the effect of urban, proposed and zoning landuse. Its also capable to predict the results of smart growth initiatives for sustainable development to be achieved. Therefore this paper will review and discuss on how the GIS and other combined techniques are potentially into modeling a WEB-based GIS visualization of the real heritage world. This paper will focus on the discussion in establishing the WEB-based GIS together with visualization towards sustainable development of George Town (not “Georgetown” as most people used and tend to spell it) as world heritage site while application from this WEB-based is capable to become a tool for sustainable development of George Town as world heritage site. It is expected that by using WEB-based GIS many users are capable to analyst the categories of heritage building in George Town, in terms of non - heritage building or heritage building and so on. Therefore it is believed that WEB-based GIS is capable to become efficient tools to be use in supporting the process of such as data sharing, decision making, manipulation of data information and map for George Town as the world heritage site.

A study on the extraction of Digital Elevation Model (DEM) using Remote Sensing and Geographic Information System (GIS) for flood risk assessment

Digital Elevation Model (DEM) has been widely used in many fields such as flight simulation, surface analysis, engineering works and flood risk assessment. In these recent years, it can be seen that the use of DEM in flood risk assessment and modeling is increasing. This paper describes a study made on the extraction of DEM using Remote Sensing and Geographic Information System (GIS) in flood risk assessment. The objective is to explore and understand the characteristics and the use of Digital Elevation Model (DEM) in flood risk assessment. There are some different sources of Digital Elevation Models (DEMs) highlighted in this paper which include ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), LiDAR (Light Detection and Ranging) and topographic map.

Image processing for facade mapping using Digital Close Range Photogrammetric (DCRP) approach

The Digital Close Range Photogrammetric (DCRP) approach in image processing has been used for documentation of cultural heritage (façade mapping) and restoration of heritage monuments for many years. The DCRP approach offers an automatic measurement process, 3D vector data, digital orthophotos and digital surface models of heritage monument, beside an alternative of the old traditional approach. Conservation and reconstructions of heritage buildings has been an important part of cultural heritage, by preparing and producing the heritage buildings façades map using appropriate geomatic image processing technology. Heritage buildings are usually characterized as an irregular geometry where it surface is complex. In this context, the DCRP approach is very applicable to be implemented. The Istana Bukit Jugra, also well known as Istana Bandar, which was built in 1915 is one of the heritage building at Selangor Darul Ehsan. Located in Kampong Bandar, the Istana Bandar or Town Palace was built by Sultan Alauddin Shah. In this paper overall view of documentation (façade mapping) for cultural heritage by using DCRP approach and general aspects of documentation of cultural heritage are presented for the Istana Bukit Jugra. The final output is a digital facade plan/map of front view of the palace together with the 3D data information consists of X, Y and Z coordinates.

Tree age estimation by tree diameter measurement using digital close range photogrammetry (DCRP)

The digital close range photogrammetry (DCRP) approach has been used for trees age estimation from its photographs with image analysis. Age of a tree can be determined using diameter or from the circumference, then convert it into diameter of a tree. The aim of this study is to determine the age of a tree by measuring tree diameter using close range photogrammetry technique. Conventional method was used to estimate the age of a tree by determining diameter at breast height (DBH) by using a measuring tape. Three jelutong trees with a different size were used in this study. Finding of the results shows the 3D representation of three sample trees with their circumference and diameter measurement compared to the conventional reading. From the analysis it was found that the different between conventional and DCRP method on tree age estimation on tree id 020, 047 and 053 yields 0.313%, 0.850% and 0.424% respectively.

Accuracy assessment of calibrating high resolution digital camera

Today many photogrammetric works involved the use of digital cameras due to its in low cost. Digital camera has been used in many photogrammetric applications such as archaeology, architecture, accident investigation, cultural heritage and etc. Theoretically, most digital camera is known as non-metric camera where the interior geometrical of digital camera is not stable, however, the optical quality is not acceptable. The need for camera calibration has been fundamental requirement for obtaining accurate measurement since the inception of photogrammetry. This study deals with the acquisition and processing of different configuration of digital camera (convergent and generic network) which are position at different height versus different digital camera setup. The accuracy assessment was performed for two high resolution digital cameras which are Nikon D90 and Rollei D30metric5 digital cameras. The height of digital camera is setup at approximately 80cm and 100cm. Finally, this study evaluates the accuracy of the camera calibration based on standard deviation of interior camera calibration parameters. This study shows that high resolution Nikon D90 digital camera which is categorized as low cost could be used in photogrammetric application with good accuracy achievable.