DESIGN AND IMPLEMENTATION OF A COMPUTERIZED DATA BASE SYSTEM FOR OUTPATIENT

CHAPTER ONE

1.1 INTRODUCTION

A Geographical Information System GIS is a system of hardware, software and procedures to facilitate the management, manipulation, analysis, modeling, representation and display of georeferenced data to solve complex problems regarding planning and management of resources. Functions of GIS include data entry, data display, data management, information retrieval and analysis. The applications of GIS include mapping locations, quantities and densities, finding distances and mapping and monitoring change. There are mainly three categories of geographic positioning systems to determine or track a users location, which have been designed and proposed over the years. These systems are mainly three categories:

Global Positioning System, Widearea Location System and Indoor Positioning System. Global Positioning System GPS receives signals from multiple satellites to determine the physical location of a user.

The limitation for this system is that it is inefficient for indoor use; alongside in urban areas it often possesses difficulties in receiving signals where high buildings shield the satellite signals.

Widearea location systems are mainly based on cellular networks that involve measuring the signal strength, the angle of signal arrival and/or the time difference of signal arrival. The positioning information in widearea location systems is highly limited by the cell size or cell coverage.

Geographic Information GI represents information that can be associated to a location on Earth, information about nature phenomena, natural, cultural and human resources in general. A GIS Geographic Information System represents an ensemble of hardwaresoftware for capturing stocking, validating, managing, analyzing and visualizing data that have a geographic reference.

1.2 BACKGRAOUND

Application of Remote Sensing and GIS

Function of an Information system is to improve ones ability to make decisions. An Information system is a chain of operations starting from planning the observation and collection of data, to store and analysis of the data, to the use of the derived information in some decision making process. A GIS is an information system that is designed to work with data referenced to spatial or geographic coordinates. GIS is both a database system with specific capabilities for spatially referenced data, as well as a set of operation for working with data. There are three basic types of GIS applications which might also represent stages of development of a single GIS application.

A. Inventory Application

Many times the first step in developing a GIS application is making an inventory of the features for a given geographic area. These features are represented in GIS as layers or themes of data. The emphasis at this stage of application development consists of updating and simple data retrieval.

B. Analysis Application

Upon completion of the inventory stage, complex queries on multiple layers can be performed using spatial and spatial analysis techniques.

C. Management Application

More advanced spatial and modeling techniques are required to support the decisions of managers and policy makers. This involves shifting of emphasis from basic geographic data handling to manipulation, analysis and modeling in order to solve real world problems.

D. Uses of Coastal GIS Packages

1. Retrieval of information of any specific site.

2. Provision of summary data for planning purpose.

3. Graphical display for educational and public relation exercise.

4. Classification of coasts and management zone.

5. Predicting modeling to determine.

i. Projections of coastal changes.

ii. Impacts of individual schemes.

iii. Impacts from changes of use.

iv. Impacts from natural calamities.

1.3 Statement of Problem:

The application of GIS is so enormous that it is only limited to the mindset of the administrators and users. This project therefore focuses on the visualization and manipulation of geospatial information to support decision making in urban development and other areas the GIS can be applied.