Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Detailed building footprints from LiDAR


Frequently, with spatial analyses, we receive data in one form that seems quite promising but we need it in another more extensive form. LiDAR is an excellent solution for such problems; LiDAR data is laser scanned either from an airborne platform, such as a fixed-wing plane or helicopter, or from a ground unit. LiDAR devices typically return a cloud of points referencing absolute or relative positions in space. As a raw dataset, they are often not as useful as they are once they have been processed. Many LiDAR datasets are classified into land cover types, so a LiDAR dataset, in addition to having data that contains x, y, and z values for all the points sampled across a space, will often contain LiDAR points that are classified as ground, vegetation, tall vegetation, buildings, and so on.

As useful as this is, the data is intensive, that is, it has discreet points, rather than extensive, as polygon representations of such data would be. This recipe...