Preface

In the past, professional spatial analysis in the business sector was equivalent to buying an ArcGIS license, storing the data in some kind of Esri database, and publishing results with the ArcGIS Server. These trends seem to be changing in the favor of open source software. As FOSS (free and open source software) products are gaining more and more power due to the hard work of the enthusiastic open source GIS community, they pique the curiosity of the business sector at a growing rate. With the increasing number of FOSS GIS experts and consulting companies, both training and documentation--the two determining factors that open source GIS products traditionally lacked--are becoming more available.

What this book covers

Chapter 1, Setting Up Your Environment, guides you through the basic steps of creating an open source software infrastructure you can carry out your analyses with. It also introduces you to popular open data sources you can freely use in your workflow.

Chapter 2, Accessing GIS Data with QGIS, teaches you about the basic data models used in GIS. It discusses the peculiarities of these data models in detail, and also makes you familiar with the GUI of QGIS by browsing through some data.

Chapter 3, Using Vector Data Effectively, shows you how you can interact with vector data in the GIS software. It discusses GUI-based queries, SQL-based queries, and basic attribute data management. You will get accommodated to the vector data model and can use the attributes associated to the vector features in various ways.

Chapter 4, Creating Digital Maps, discusses the basics of digital map making by going through an exhaustive yet simple example in QGIS. It introduces you to the concept of projections and spatial reference systems, and the various steps of creating a digital map.

Chapter 5, Exporting Your Data, guides you through the most widely used vector and raster data formats in GIS. It discusses the strengths and weaknesses of the various formats, and also gives you some insight on under what circumstances you should choose a particular spatial data format.

Chapter 6, Feeding a PostGIS Database, guides you through the process of making a spatial database with PostGIS. It discusses how to create a new database, and how to fill it with various kinds of spatial data using QGIS. You will also learn how to manage existing PostGIS tables from QGIS.

Chapter 7, A PostGIS Overview, shows what other options you have with your PostGIS database. It leaves QGIS and talks about important PostgreSQL and PostGIS concepts by managing the database created in the previous chapter through PostgreSQL's administration software, pgAdmin.

Chapter 8, Spatial Analysis in QGIS, goes back to QGIS in order to discuss vector data analysis and spatial modeling. It shows you how different geometry types can be used to get some meaningful results based on the features' spatial relationship. It goes through the practical textbook example of delimiting houses based on some customer preferences.

Chapter 9, Spatial Analysis on Steroids - Using PostGIS, reiterates the example of the previous chapter, but entirely in PostGIS. It shows how a good software choice for the given task can enhance productivity by minimizing manual labor and automating the entire workflow. It also introduces you to the world of PostGIS spatial functions by going through the analysis again.

Chapter 10, A Typical GIS Problem, shows raster analysis, where spatial databases do not excel. It discusses typical raster operations by going through a decision making process. It sheds light on typical considerations related to the raster data model during an analysis, while also introducing some powerful tools and valuable methodology required to make a good decision based on spatial factors and constraints.

Chapter 11, Showcasing Your Data, goes on to the Web stack, and discusses the basics of the Web, the client-server architecture, and spatial servers. It goes into details on how to use the QGIS Server to create quick visualizations, and how to use GeoServer to build a powerful spatial server with great capabilities.

Chapter 12, Styling Your Data in GeoServer, discusses the basic vector and raster symbology usable in GeoServer. It goes through the styling process by using traditional SLD documents. When the concepts are clear, it introduces the powerful and convenient GeoServer CSS, which is also based on SLD.

Chapter 13, Creating a Web Map, jumps to the client side of the Web and shows you how to create simple web maps using the server architecture created before, and the lightweight web mapping library--Leaflet. It guides you through the process of creating a basic web map, ranging from creating an HTML document to scripting it with JavaScript.

Appendix shows additional information and interesting use cases of the learned material through images and short descriptions.

What you need for this book

For this book, you will need to have a computer with mid-class computing capabilities. As the open source GIS software is not that demanding, you don't have to worry about your hardware specification when running the software, although some of the raster processing tools will run pretty long (about 5-10 minutes) on slower machines.

What you need to take care of is that you have administrator privileges on the machine you are using, or the software is set up correctly by an administrator. If you don't have administrator privileges, you need to write the privilege at least to the folder used by the web server to serve content.

Who this book is for

The aim of this book is to carry on this trend and demonstrate how even advanced spatial analysis is convenient with an open source product, and how this software is a capable competitor of proprietary solutions. The examples from which you will learn how to harness the power of the capable GIS software, QGIS; the powerful spatial ORDBMS (object-relational database management system), PostGIS; and the user-friendly geospatial server, GeoServer are aimed at IT professionals looking for cheap alternatives to costly proprietary GIS solutions with or without basic GIS training.

On the other hand, anyone can learn the basics of these great open source products from this practical guide. If you are a decision maker looking for easily producible results, a CTO looking for the right software, or a student craving for an easy-to-follow guide, it doesn't matter. This book presents you the bare minimum of the GIS knowledge required for effective work with spatial data, and thorough but easy-to-follow examples for utilizing open source software for this work.

Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, and user input are shown as follows: "It uses the * wildcard for selecting everything from the table named table, where the content of the column named column matches value."

A block of code is set as follows:

    SELECT ST_Buffer(geom, 200) AS geom
     FROM spatial.roads r
     WHERE r.fclass LIKE 'motorway%' OR r.fclass LIKE 'primary%';

Any command-line input or output is written as follows:

    update-alternatives --config java

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "If we open the Properties window of a vector layer and navigate to the Style tab, we can see the Single symbol method applied to the layer."

Note

Warnings or important notes appear in a box like this.

Note

Tips and tricks appear like this.

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