Book Image

Learning Geospatial Analysis with Python

By : Joel Lawhead
Book Image

Learning Geospatial Analysis with Python

By: Joel Lawhead

Overview of this book

Geospatial Analysis is used in almost every field you can think of from medicine, to defense, to farming. This book will guide you gently into this exciting and complex field. It walks you through the building blocks of geospatial analysis and how to apply them to influence decision making using the latest Python software. Learning Geospatial Analysis with Python, 2nd Edition uses the expressive and powerful Python 3 programming language to guide you through geographic information systems, remote sensing, topography, and more, while providing a framework for you to approach geospatial analysis effectively, but on your own terms. We start by giving you a little background on the field, and a survey of the techniques and technology used. We then split the field into its component specialty areas: GIS, remote sensing, elevation data, advanced modeling, and real-time data. This book will teach you everything you need to know about, Geospatial Analysis from using a particular software package or API to using generic algorithms that can be applied. This book focuses on pure Python whenever possible to minimize compiling platform-dependent binaries, so that you don’t become bogged down in just getting ready to do analysis. This book will round out your technical library through handy recipes that will give you a good understanding of a field that supplements many a modern day human endeavors.
Table of Contents (17 chapters)
Learning Geospatial Analysis with Python Second Edition
About the Author
About the Reviewers

Measuring distance

The essence of geospatial analysis is discovering the relationships of objects on the Earth. Items which are closer together tend to have a stronger relationship than those which are farther apart. This concept is known as Tobler's First Law of Geography. Therefore, measuring distance is a critical function of geospatial analysis.

As you have learned, every map is a model of the Earth, and they are all wrong to some degree. For this reason, measuring accurate distance between two points on the Earth while sitting in front of a computer is impossible. Even professional land surveyors who go out in the field with both traditional sighting equipment and very precise GPS equipment fail to account for every anomaly on the Earth's surface between point A and point B. So, in order to measure distance, we must look at what we are measuring, how much we are measuring, and how much accuracy we need.

There are three models of the Earth we can use to calculate distance:

  • Flat plane

  • Spherical...