Sayısal haritaların coğrafi bilgi sistemlerinde kullanılması ve kordinat transformasyonu /

Abstract

Bu çalışmada, büyük ölçekli sayısal haritaların Coğrafi Bilgi Sistemlerinde kullanılması ve koordinat transformasyon problemlemleri ele alınmıştır. Çalışmanın birinci bölümünde, genel olarak zaman, bilgi ve teknolojinin ulaştığı seviyenin günümüzde bilgi sistemlerinin kurulmasının zorunlu hale geldiği vurgulanmış, özellikle büyük kentlerde coğrafi bilgi sistemlerinin kurulmasının gerekliliğine dikkat çekilmiştir. İkinci bölümde, coğrafi bilgi sistemini oluşturan unsurlar olan coğrafya, bilgi, veri, tarihi gelişimi, ülkemizdeki uygulanabilirliği, veritabanı ve veritabanı yönetim sistemleri, farklı meslek dalları ile ilişkileri, verilerin ortak paylaşımı, teknolojik ve organizasyonel bileşenleri açıklanmıştır. Üçüncü bölümde, bir coğrafi bilgi sistemi uygulama örneği olan İGABİS (İGDAŞ Altyapı Bilgi Sistemi) başlangıç aşamasından bugüne kadar gelişim süreci, yapılan uygulamalar, karşılaşılan problemler, çözüm yolları ve gelecekteki hedefler incelenmiştir. Dördüncü bölümde, coğrafi bilgi sistemlerinin harita modül kısmını oluşturan büyük ölçekli sayısal haritaların kullanılabilirliği, sisteme entegrasyonu ve ülkemizdeki sayısal harita üretimi irdelenmiştir. İstanbul Beyoğlu bölgesinde iki büyük caddeye ait (M. Mebusan ve İstiklal Caddeleri) farklı zamanlarda, farklı kurumlarca ve farklı yöntemlerle üretilen haritalar irdelenmiştir. Lokal olarak üretilen büyük ölçekli sayısal sokak haritaları ve 1/1000 ölçekli fotogrametrik sayısal haritalar kullanılarak; M. Mebusan Caddesinde 6 adet eşlenik nokta seçilerek grafik ortamda (Geographies programında) afin dönüşümü yapılmış elde edilen sonuçlardan koordinat farkları ve lineer kapanma hataları hesaplanmıştır. Aynı cadde için 5 eşlenik nokta kullanılarak Helmert dönüşümü uyuşum testi yapılmış, elde edilen sonuçlardan koordinat farkları ve lineer kapanma hataları hesaplanmıştır. - İstiklal Caddesinde 5 adet eşlenik nokta kullanılarak yine grafik ortamda afin dönüşümü yapılmış elde edilen sonuçlardan koordinat farkları ve lineer kapanma hataları hesaplanmıştır. Aynı caddeler için farklı yöntemlerle yapılan dönüşümler ve İGDAŞ tarafından grafik ortamda öteleme ve döndürme işlemleri ile yapılan dönüşümler ile karşılaştırılmış ve üretilen haritaların doğrulukları irdelenmiştir. Bulunan sonuçlar, tablo ve grafiklerle gösterilmiş ve sonuçlar karşılaştırılmıştır. Son bölümde ise, coğrafi bilgi sistemi uygulamalarına zaman geçirmeden başlanılması gerektiği tekrar vurgulanmış ve transforme edilmiş sokak haritalarının altyapı sistemlerinde uygulanabilecek doğruluğa sahip oldukları ancak, bu çalışmalarla elde edilmiş haritaların kentsel kadastro çalışmalarında kullanılamayacağı, buna karşılık Coğrafi Bilgi Sistemi uygulamalarından olan Altyapı Bilgi Sistemleri için kullanılabileceği belirtilmiştir. xı

Time has obliged new expressions to enter our lives by emphasizing the importance of knowledge and technology more and more Geographic Information System is a very fresh expression which is newly becoming ripe in the world. But not well known in Turkey. GTS (Geographic Information Systems) is a computer-based system that handles the input, management, manipulation, analysis, and output of spatial and tabular data. Spatial data is referenced to specific locations on the earth and is stored as graphic elements. Tabular data is non-graphic attributes tied to spatial data and stored in a relational database. Enter the last decade of what has to be the greatest century of change in the history of mankind. It seems appropriate to take this opportunity to reflect for a moment on where we are, and most importantly, where we are going to with information technology in general and GIS technology in particular. One of the interesting things about GIS is that it has such a varied background. In the late 1960s and early 1970s, several development efforts paralleled each other; the resulting products are now collectively known as GIS. At present, vendors of GIS or AM/FM systems are attempting to diminish the appearance of any difference between GIS and AM/FM functionality. The system vendors are making an effort to provide all the major functions a client needs, regardless of whether the applications require AM/FM or GIS functionality. This has created the use of the term AM/FM /GIS. Currently, the marketplace appears to be replicating this term with GIS to mean all aspects of AM/FM/GIS. Throughout this publication, the term GIS is used to refer to all aspect of AM/FM and/or GIS. Recently, many organizations are spending large amounts of money on GISs and on geographic databases. Because the geography with the data describing it is a part of human's everyday life; almost every decision is constrained influenced or dictated by some facts of geography. It means that the GIS is not only a need,but also an opportunity. Maps are specific coverage within the project area as defined by a map index shape. Each map is comprised of some or all features for a specific category. Map names and category information are stored in the maps system table. Many organizations own and operate geographically dispersed facilities, such as electric lines, gas lines, sewer lines, telephone cables, traffic lights, and/or water mains. These facilities must be efficiently planned, designed, constructed, operated, maintained, and managed. xu Features User Data Commands Figure 1. The figure of A Project of GIS GIS is used different field of application: Multi-disciplinary GIS; Agencies and offices within a municipality or region can access a single GIS database to meet their own application-specific needs for data. For example, ifa county establishes a centralised GIS, it may be used by the:. School Board to modify school districts and develop transportation plans.. Public Works Department to maintain and upgrade the road system.. Recycling Office to plan efficient waste collection routes.. Registrar of Voters to manage ward boundaries and generate voter lists.. Tax Assessment Office to maintain a file of properties and owners.. Environmental Agency to monitor hazardous waste and groundwater quality. Each organisation would access the data that was of value to their particular needs and, in an ideal situation, each organisation would be responsible for the maintenance of their own dataset within the GIS. Municipal Utilities; Public services such as water, electricity, gas, and telephone are provided to the residents and businesses in a municipality. Utility managers must make intelligent and well-informed decisions regarding these facilities. Until recently, they had to rely on various hard copy documents as the best source of information: maps and plans for spatial information, and paper files and billing documents for associated attribute data. Managers can now use a GIS to view a map at any logical scale, check map features, or query the associated database tables. For example, an inquiry regarding water mains that have not been serviced for a specified period of time could produce a tabular report or a plotted map. When construction work is planned for a particular area, the GIS provides information to create work orders. It can be used to generate Xlll mailing labels based on address ranges or geographic locations to inform residents of pending work. GIS tools can help predict the demand on services due to new housing or interruptions in existing services. Emergency Response Systems; Computer-aided dispatch systems for fire departments, ambulance services, and police forces are used in many urban centers to find the optimal route to an accident scene. Route selection can be based on a number of weighted factors such as distances, road widths, traffic patterns, weather conditions, and construction. Rural and Urban Planning: GIS provides information to help in planning decisions such as selecting the best site for a new facility based on diverse requirements and criteria. For example, the site for a new ambulance station could be based on population distribution, accessibility to major roads and highways, local traffic patterns, and proximity to other facilities like hospitals and fire halls. Use GIS as a modelling system to determine optimal school bus routes based on student distribution, road quality, and minimal travel distances. It can also be used to assist in redistricting of school boundaries based on proximity of students to schools, traffic hazards, current housing development, and population trends. Cartography and Thematic Mapping; CAD systems are used extensively for the automated production of maps. Traditionally, vast amounts of information was stored in the static visual presentation of a map; feature characteristics were portrayed with varying symbology and the display scale of map information was fixed to a great extent. With a GIS approach to cartographic production, a feature database can be used to drive resymbolization and feature selection based on specifications for various themes and map scales. Also, statistical data can be combined with geographic data to produce thematic maps or special-purpose maps. GIS operations can be used to analyze data, merge geographic boundaries, and generate new maps based on the results of analysis. Cadastral Mapping; Use GIS within a municipality to build and maintain a geographic database of all property descriptions and related data such as registered owners and assessed values. This information can be made accessible to property owners and developers for real estate purposes, and to government officials for taxation purposes. Management of Natural Resources; GIS is used by various levels of government and resource industries to maintain an inventory, monitor changes, and manage various natural resources such as agriculture and forestry. In a forestry application, analysis based on buffer zone generation, area measurement, and overlay of polygons can aid in planning timber harvests, determining access routes, planning reforestation efforts, and generating reports for government agencies. Demographic Studies for Business; GIS is regularly used to help retailers and service providers ascertain population distribution and consumer buying patterns. This information can be used in advertising and direct mail campaigns, to formulate sales districts and identify areas for marketing, to locate customers, and schedule deliveries with time- and cost-effective routing. Businesses use GIS to identify prime locations for a new retail outlet based on local population distribution and characteristics, spending patterns, proximity to major streets, zoning fabric, property values, etc. xi v The SQL Manager enables you to review and edit database linkages to features and the non-graphic attributes of the features. It also allows you to locate associated map features across a map library. A data extraction facility enables the creation of new data sets from a map library using a combination of spatial and database filtering criteria. In the software which has relational database interface allows you to connect to a wide range of client/server database systems. Transformation Affine transformation uses the following set of normal equations to approximate x',y' (the target coordinates), given x and y (the source coordinates): A(x,y) = x* = cl * x + c2 * y + c3 B(x,y) = y' = c4 * x + c5 * y + c6 The six coefficients are calculated by solving a system of six linear equations of the partial derivatives and using the control points to substitute for x,y and x',y'. The affine transformation works best minimizing the distance in x and the distance in y. It but does a poor job in the overall distance minimization. Helmert transformation that has two dimensional linear defend angle A(x,y) = X = a*x-b*y + c B(x,y) =Y=b*x+a*y+d The four coefficients are calculated by solving a system of four linear equations of the partial derivatives and using the control points to substitute for x,y and X, Y. The best characteristic of Helmert is fixed scale In GIS, topology refers to the spatial relationships between elements. For example, an area is defined by a set of bounding linear elements. Adjacency between areas and connectivity between linear elements are also topological concepts. Features graphic elements that represent real world objects Each feature has defined symbology and element types and belongs to a single category. Features with related database information also include the name of a user attribute table within their feature definition. A category is a grouping of similar features, often arranged in a hierarchical order. A Category is defined by the Maps and Features that comprise it. Each map and each feature belong to only one category, but a category can have many maps and any number of features. Warping, or rubber sheeting, is the transformation of graphic elements to fit a known set of monuments. For example, you may change files developed from a local coordinate system to a U.T.M. Plane Coordinate System, or you may warp a digitized map to match a digital image. Two types of benefits can be realized with the use of a GIS. Quantitative or hard benefits are those benefits that can be measured and quantified in specific economic terms. Qualitative or soft benefits cannot be directly quantified or measured, but can ultimately impact the economics of a GIS project. Input Hardware Keyboard xv Command Tablet Graphic Input Device Digitizing Tablets Scanners Pen-Based Laptop/Hand-Held PCs Output Hardware Pen Plotters Raster Plotters Screen Copy Devices Computer FAX Printers One of the biggest factors influencing the degree of complexity of a GIS data conversion project is the quality and coverage of the source data. An analysis of the quality coverage of possible source is required because a particular GIS feature is often shown on multiple sources of varying quality. The quality source materials must be equal to or greater than the desired quality of the converted database; otherwise the source should be rejected and replaced. For example, if maps do not show the required information with appropriate accuracy, precise calculations or aerial mapping may have to be used to provide the data. This underlines the importance of identifying the quality of sources as part of database definition, before the cost conversion is estimated and quoted, and data conversion begun. The parameters that follow describe the quality and coverage of source material; they are similar to the ones used to assess the quality and coverage of the database itself. Accuracy - Reliability Coverage - Convenience Completeness - Condition Timeliness - Readability Correctness - Precedence Credibility - Maintainability Validity There are three categories of data within GIS for which data quality has to be defined: the graphic features, with their position and representation; the attributes; and the database intelligence. The firs chapter contains a general view to this study and deal with the importance of data needs. The relation GIS, GPS (Global Position Systems) and surveying engineer is also given. Third chapter is dedicated to the design and implementation of GIS plot project about IGDAS in ISTANBUL which is good application in the future for Istanbul's people. Because of learning about our neutral gas line underground, querying lots of questions and digressing risk of emergency. It is containing the creation of geographic database and basic spatial analysis and gueryies to produce reports and maps. The fourth chapter, there are used different three maps which are local maps, photogrammetric (Universal Transversal Mercator-UTM) maps and new produced xvi maps in IGABIS (IGDAS Infrastruction Information System). Because of different coordinate system of local maps is the biggest problem to use GIS. So we do not know about its accuracy. We transformed large scale local maps with Affine and Helmert methods. Affine transformation method is used on the graphic environment but Helmert method used only calculation environment so we calculated accuracy of points. Then we compared maps that transformed by IGDAS and our maps on the UTM systems maps. In the fifth and final chapter it is presented some results, suggestions and opinions, about GIS, data standardisation and transformation of maps accuracy. At the and of the transformation, old produced large scale local maps and new large scale maps are used Infrastruction Information System but not used city cadastral application. xvn