Book Image

Learning Geospatial Analysis with Python

By : Joel Lawhead
4 (1)
Book Image

Learning Geospatial Analysis with Python

4 (1)
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. It is an approach to use statistical analysis and other informational engineering to data which has a geographical or geospatial aspect. And this typically involves applications capable of geospatial display and processing to get a compiled and useful data. "Learning Geospatial Analysis with Python" uses the expressive and powerful Python programming language to guide you through geographic information systems, remote sensing, topography, and more. It explains how to use a framework in order to approach Geospatial analysis effectively, but on your own terms. "Learning Geospatial Analysis with Python" starts with a background of the field, a survey of the techniques and technology used, and then splits the field into its component speciality areas: GIS, remote sensing, elevation data, advanced modelling, and real-time data. This book will teach you everything there is to know, from using a particular software package or API to using generic algorithms that can be applied to Geospatial analysis. 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. "Learning Geospatial Analysis with Python" will round out your technical library with handy recipes and a good understanding of a field that supplements many a modern day human endeavors.
Table of Contents (17 chapters)
Learning Geospatial Analysis with Python
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Reprojection


While reprojection is less common these days, because of more advanced methods of data distribution, sometimes you need to reproject a shapefile. The pure Python utm module works for reference system conversion, but for a full reprojection we need some help from the OGR Python API.

As an example we'll use a point shapefile containing museum and gallery locations in the Lambert conformal projection. We'll reproject it to WGS84 geographic (or unproject it rather). You can download this zipped shapefile at:

https://geospatialpython.googlecode.com/files/NYC_MUSEUMS_LAMBERT.zip

The following minimalist script reprojects the shapefile. The geometry is transformed and then written to the new file, but the dbf file is simply copied to the new name as we aren't changing it. The standard Python shutil module, short for shell utilities, is used to copy dbf. The source and target shapefile names are variables at the beginning of the script. The target projection is also near the top which...