http://repository.unn.edu.ng/handle/123456789/4449 2026-09-02T19:57:23Z http://repository.unn.edu.ng/handle/123456789/6383 Development of Datum Transformation Procedure for Nigeria Based on National Transformation Version 2 (NTv2) Model Hart, Lawrence Positions of geodetic network of points in Nigeria in terms of horizontal coordinates in the local Minna datum were established using classical survey methods resulting in varying degree of accuracy. However, with the advent of modern technology, such as the Global Positioning System (GPS), coordinates that are more homogenous and with higher accuracy are now easily determined. To integrate geospatial data (coordinates) based on local and global datums there is need to determine acceptable transformation parameters for Nigeria, which will ensure proper data integration and effective use of Global Positioning System (GPS). This research aimed to develop a suitable datum transformation procedure for Nigeria based on the Canadian National Transformation Version 2 (NTv2) model. The specific objectives were to: (i) determine the seven (7) optimal transformation parameters (using Molodensky-Badekas model) and their corresponding standard deviations for Nigeria, (ii) generate the regular Grid Shift file based on the NTv2 model for Nigeria and (iii) create computer based forms and components to enable friendly Graphic User Interface (GUI) in the transformation of coordinates from local (Minna) datum to global (WGS84). The similarity conformal transformation approach based on the Molodensky-Badekas model and least squares interpolation techniques (grid based) were used in developing a transformation procedure for Nigeria. In addition, the bi-linear interpolation and the least square collocation techniques (covariance function) were used to model distortion and determine transformation components in latitude (Δp) and longitude (Δp) with corresponding accuracies at the grid nodes. The Visual Basic.6 (VB.6) computer programming language was employed in adding functionality, in a code-behind-file model which was served to the web pages using Active Server Pages.Net server side programming language. The seven transformation parameters obtained for Nigeria with their standard deviations were ���� = 93.83753636758280 ± 0.40683128890m, ���� = 89.476395081711 ± 0.406523878m, Dz = −118.8114111450710 ± 0.4064409664m,Rx = 0.000010675828398rad ± 0.000001095445115",Ry = 0.000001686966862rad ± 0.0000016733200530",Rz = 0.000002042700900rad ± 0.000001414213562",L = 1.000005727067014 ± 0.000001095445115m The unit variance of the adjusted parameters 02 was 6.931937 and at 95% confidence interval, a t-test revealed that the a priori variance factor was 5.4262  02  8.7282 therefore the null hypothesis is not rejected (H0: 02 = 1is not rejected). The grid shift file for Nigeria with fundamental grid parameters were developed to be deployed for GIS software applications. The standard error (accuracy) of transformed coordinates obtained by the application of the NTv2 model was in the range of ±0.037-0.184m (latitude) and ±0.0260.281m (longitude). A PC and Web-Based Graphic User Interface for single and batch data coordinate transformation in Nigeria were developed. Finally, this research present the tools developed to facilitate datum transformation including the grid file generated based on NTv2 format to make datum transformation process simpler. It is hereby recommend that the Office of the Surveyor General of the Federation (OSGOF) should embark on the provision of first order controls as common points to facilitate determination of improved parameters. This is in addition to a more aggressive campaign and advocacy about coordinate transformation and its procedures based on NTv2 model to all stakeholders and geospatial users. 2015-03-01T00:00:00Z http://repository.unn.edu.ng/handle/123456789/6319 Application Of Remote Sensing And Gis In The Population Study Of Achara Layout Enugu, Enugu State, Nigeria OZOEKWE, CHARLES IFEANYI This project is an attempt to study population distribution in Achara Layout Enugu, in Enugu State through integration of Remote sensing and Geographic Information System (GIS). The Remote sensing data used in this study included high spatial resolution Quick Bird imagery. Questionnaires were given out for use in generating the desired product in an interactive GIS environment. Field site capturing was based on basic survey principle, technique and instruction. Field work was done to determine the type of building appearing in the satellite imagery and the no of rooms estimated, thus a standard family size gotten. After estimating the population size of Achara Layout, the result was compared to the population data gotten from National Population Commission for Achara Layout Enugu state which was divided into two as it comprised of data for Achara Layout and Idaw River Layout Enugu as directed by National Population Commission Enugu. The methodology involved carrying out a user needs assessment, collection of map from Enugu State Town Planning Department of Ministry of Land, collection of Population census data from National Population Commission, rigorous field work, data processing, comparison of results and presentation of results. The average difference between the population recorded in the 2006 then projected to 2015, and that estimated from Quick Bird images for Achara Layout Enugu, is found to be equal to 1.61%. Results from Arc GIS were presented in form of map while results from Microsoft Excel environment were presented in form of table. 2015-12-01T00:00:00Z http://repository.unn.edu.ng/handle/123456789/6060 As-Built Surveying For The Facility Retrofitting Of An Offshore Gas Plant Using Leica Scanstation 2 High Definition Surveying Instrument Nwaka, Okwuchukwu Christopher 3D as-built models have been utilized over the years as an aid to several engineering activities and there are conventional survey methods; e.g. Total Station ray method, photogrammetric technique etc., with which the data required for these models are generated. These methods have proven not to be optimal in capturing datasets required for the modeling of some complex engineering structures. The reasons for this been the intrusive nature of some of these methods and their point rather than surface sampling abilities.Others include the time taken to generate enough data as required and the average overall low accuracy achievable by these methods. This had led to several 3D models been a product of various degrees of interpolations and its attendance loss in model accuracy. High Definition Surveying (HDS) is a non-intrusive surveying method for collecting timely, accurate and complete geometric data of existing sites and structures.The HDS method has the capability of capturing tens of thousands of surface points in a second, making it very suitable for generating data required for the modeling of complex surfaces and structures. In this project, the ability and suitability of the HDS technique for use in complex and usually volatile oil and gas environments were proven as it was utilized for the production of the 3D model required as an aid for the retrofitting of an offshore gas platform. The Leica ScanStation 2 was deployed for the data capture alongside the Cyclone application program, the Cyclone program was also utilized for the processing of the measured data as well as production of a topologically and geometrically accurate 3D model of the required section of the platform. The produced model was subjected to some physical tests/checks to certify its correctness. Data interoperability was also achieved as the resulting 3D model as well as cloud of points were viewed and analyzed from various application programs e.g. AutoCAD. Further research was however recommended especially in the area of methods of quality assurance of completed models as the physical methods currently been utilized is not only slow, but also gives an indication of the presence of an error without giving an idea of its source and how it can be corrected. 2015-10-01T00:00:00Z http://repository.unn.edu.ng/handle/123456789/5115 As-built Model of the Central Bank of Nigeria (CBN) Centre of Excellence Building University of Nigeria Enugu Campus Using Leica HDS Scanstation 2 Okoroafor, Victor Chuma Laser scanning technology has grown to become a useful surveying tool in many industries in the last decade. Laser scanning is now used in many areas such as surveying, engineering, mining, architecture, archaeology, crime investigation and control, agriculture, historic documentation, industrial pipe plant surveys etc. A laser scanner is a powerful surveying tool that is able to survey and record about 50,000 (fifty thousand) points in a second. This gives today’s surveyors the option of recording vast amounts of field data in a fast and accurate way. In recent times the study of engineering structures has been on the rise for several uses, varying from as-built survey, deformation studies, improved planning for renovations to more accurate modeling of a building, control of the verticality of a high rise building, disaster assessment and management, etc. As-built drawings are drawings that represent the actual built structure. Not as it was designed, but as it actually is today (i.e. the day of measurement). People always make changes to their designs during the construction process and these changes almost never make it back to a set of revised plans because it was made in the field, there’s no reason to update the plans, whose sole purpose is to tell the builder what to build. Also, a building of any vintage may have had additional projects that made alterations to its original form, that may have affected everything from interior finishes to the core structural system of the building (and this includes brand new buildings too). More often than not, these projects are executed without permits, plans, and in the worst cases, without the guidance of someone who knows what they are doing. These observations point to the need for methods to create as-built models. The creation of an as-built model involves measuring the geometry and appearance of an existing facility to obtain a collection of spatial data and transforming those measurements into a high-level, semantically rich representation (i.e. As-built Model). This study will be determining the as-built survey of the Centre of Excellence Building in the University of Nigeria, Enugu Campus and establish deformation monitoring framework for the building. Although as-built building information is useful, the current process for capturing, retrieving, and modeling, such information requires a lot of manual, time-consuming work. This labour intensive and time-consuming nature increases the cost of using as-built building information in practice. In order to address these issues, this project investigates the potentials of using High Definition Surveying (HDS) terrestrial laser scanning equipment named Leica ScanStation 2 to generate millions of point cloud spatial data for automatically capturing, retrieving, and modeling the exterior as-built building geometry and features in a very short time. The point cloud was georeferenced to a real world coordinate system established around the building by static GPS observation. Although this study was supposed to establish deformation monitoring framework for the building, the massive construction work still going on at the time of this project execution, will disturbed any monitoring point established on the structure hence this study will only demonstrate the possibility of using Leica ScanStation 2 for deformation monitoring using seven points fixed on the building for deformation monitoring. The results from the scanning sessions were analysed with Cyclone software to produce a 3D view of point clouds and a 3D view of as-built model of the structure exported to AutoCAD format. This result is useful in capturing construction deviations from construction documents, resource for future maintenance and planning and provides a snapshot of existing design. 2015-10-01T00:00:00Z